Midterm Flashcards

(197 cards)

1
Q

1.Approach to the Surgical Patient

A
  • Chief complaint
  • History of present illness
    • pain
    • vomiting
    • change in bowel habits
    • hematemesis,rectal bleeding
    • trauma
  • Past Medical history
    • drugs,ROS
  • Past surgical history
  • OB/GYN history
  • Social and family history
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2
Q

1.1.Approach to the Surgical Patient

A
  • Physical examination
    • Elective surgical examination
    • Examination of body orifices
  • <c>ABCDE
    <ul>
    <li>
    <strong>C</strong>atastrophic Haemorrhage control</li>
    <li>
    <b>A</b>irway (cervical spine control when appropriate)</li>
    <li>
    <strong>B</strong>reathing</li>
    <li>
    <b>C</b>irculation</li>
    <li>
    <strong>D</strong>isability</li>
    <li>
    <strong>E</strong>xtremity-environment-exposure</li>
    </ul>
    </c>
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3
Q

1.2.Approach to the Surgical Patient

A
  • Provisional diagnosis
    • most probable diagnosis so far
  • Differential diagnoses
    • list of probable diagnoses to rule out
  • Lab & other studies
    • blood tests
    • urine tests
    • functional studies : ECG etc
  • Imaging test
    • X-ray
    • ultrasound
    • CT,MRI
  • Special investigations
    • colonoscopy
    • angiography
    • cytoscopy
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4
Q

2.Types of Healing

A

Primary healing (first intention)

  • Tissue is clean
  • Reapproximation with sutures
  • Healing without complication, minimal scarring

Secondary Healing (second intention)

  • Infected wounds & burns
  • Open wound
  • Formation of granulation tissue

Delayed primary closure (third intention)

  • Secondary healing for 5 days
  • Then primary closure
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5
Q

3.Granulation Tissue

A
  • Red,moist,granular tissue
  • Appears during healing of open wounds
  • Microscopy : collagen, new blood vessels, fibroblasts, inflammatory cells
  • Healing achieved by creation of scar tissue
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6
Q

4.Wound Healing

Hemostasis & Inflammation

A
  • 0-5th day after injury
  • Platelet aggregation to exposed subendothelial collagen (IGF-1,TNFa,b, PDGF)
  • Coagulation cascade: fibrin clot⇒ coagulation &scaffolding
  • Chemotaxis : Damaged endothelial cells ⇒ activation of complement components
  • Inflammatory cells :
    • Neutrophils & monocytes 24-48h : rolling and adhesion
    • Macrophages 48-96h
    • T-lymphocyes peak at 7 days
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7
Q

4.1.Wound Healing

Proliferation

A
  • 4-14 days
  • Fibroblast replication
  • Platelets release PDGF,IGF-1,TGFb
  • Macrophages and fibroblasts release FGF,IGF-1,VEGF,IL-1,2,8, PDGF, TGFa,b
  • Fibroblasts produce collagen and proteoglycans
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8
Q

4.2.Wound Healing

Angiogenesis

A
  • 2nd to 4th day after injury
  • Response to chemoattractants from platelets and macrophages
  • PDGF,FGF,TNFa,b,VEGF
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9
Q

4.3.Wound Healing

Epithelization

A
  • starts from wound edges
  • Low PO2⇒TGFb from epithelial cells⇒blocks differentiation and promotes mitosis
  • Wound needs to be moist to promote epithelization
  • Exudate contains : growth factors and lactate
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10
Q

4.4.Wound Healing

Maturation & Remodeling

A
  • 8d-months
  • Fibroblasts replace fibrin ECM with collagen monomers⇒polymerization and cross-linking
  • ECM evolution : fibronectin, collagen III,glycosaminoglycans,proteoglycans,collagen I
  • Remodeling⇒collagen lysis and turnover (MPPs)
  • Collagen deposition>>collagen lysis
  • Fibroblasts attach to collagen fibres⇒wound contraction
  • Negative effect of contraction⇒deformation,stricture
  • Wound stretching if tension>>contraction
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11
Q

4.5.Wound Healing

Completion of Healing

A
  • Lactic acidosis and hypoxia normalization⇒stopping of healing
  • Keloids : hypertrophic scars due to local overgrowth of CT

Impaired healing

  • inadequate inflammatory response : corticosteroids,immunosuppressants,chemotherapeutic drugs
  • Excessive inflammation
  • Malnutrition (weight loss,hypoalbuminemia)
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12
Q

5.Healing of Specialized Tissues

Bone

A
  • Inflammation
  • Proliferation : specialized granulation tissue (fibrocartilaginous callus)
    • osteoclasts
    • osteoblasts
    • chondroblasts
  • Bone remodeling
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13
Q

5.1.Healing of Specialized Tissues

Nerve

A
  • Brain⇒CT scar
  • Peripheral nerves⇒sheath&axon regenerates from the nerve cell but reconnects randomly distally
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14
Q

5.2.Healing of Specialized Tissues

Intestine

A
  • 4-7th day : risk of anastomotic leakage
  • Strength regained in a week
  • Peritoneal adhesions
    *
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15
Q

6.Factors Affecting Wound Healing

A
  • Systemic
    • Age
    • Nutrition
    • Smoking
    • Metabolic diseases(DM,Metabolic syndrome)
    • Drugs: corticosteroids,immunosup,chemo
    • CT disorders - Ehler-danlos,marfan syndromes
  • Local
    • Hypoxia
    • Mechanical injury
    • Infection
    • Edema
    • Irradiation
    • Ischemia
    • Foreign bodies
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16
Q

7.Chronic Wounds &Ulcers

A

Decubitus ulcers

  • prolonged pressure⇒tissue ischemia
  • prolonged contact with moisture,urine,feces
  • malnutrition
  • in immobile,elderly,operated patients
  • Treatment:
    • drainage of infected space
    • excision of necrotic tissue
    • musculocutaneous flap
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17
Q

7.1.Chronic Wounds & Ulcers

A

Venous Ulcers

  • poor perfusion and perivascular leakage of plasma
  • lower leg
  • Treatment: compression stocking,surgical treatment of vein insufficiency

Ischemic Ulcers

  • Lateral ankle and foot
  • Treatment: revascularisation,hyperbaric oxygen
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18
Q

7.2.Chronic Wounds & Ulcers

A

Diabetic Ulcers

  • Neuropathy⇒trauma
  • Microangiopathy⇒ischemia
  • Treatment: protection of the ulcer,revascularisation

Treatment of wounds & ulcers

  • Control infection w/ antibiotics
  • Treat underlying circulatory disease
  • Keep wound moist
  • Debridement of unhealthy tissue
  • Reduce autonomic vasoconstriction
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19
Q

8.Excess Healing

A

Excess dermal scarring

  • Hypertrophic scar if epithelization takes longer than 3-4 wks
  • Keloid
    • 3 months after surgery
    • keloidal fibroblasts synthesize 20x
    • treat with local steroid injection

Peritoneal scarring(adhesions)

  • Fibrin,fibroblasts &collagen⇒filmy adhesions
  • Fibrinolysis w/in a week
  • Migration of capillaries,nerves,CT⇒solid adhesions
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20
Q

9.Wound Management

Classification

A
  • I.Clean:
    • uninfected,no inflammation
    • elective surgical wounds
    • e.g.hernia,breast surgery
    • management: primary closure
    • Infection rate : <2%
  • II.Clean-contaminated:
    • Minor and brief contamination,minor inflammation
    • Clean and sharp with local damage
    • e.g.gastric surgery
    • management: primary closure and wound cleaning
    • infection rate : 1-5%
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21
Q

9.1.Wound Management

Classification

A
  • III.Contaminated:
    • Contamination apparent and prolonged,major inflammation
    • Ragged and contused wounds w/ gross local damage
    • E.g. inflamed appendectomy,penetrating wounds
    • management: copious irrigation,debridement and primary closure
    • infection rate : 5-25%
  • IV.Dirty:
    • Gross contamination w/ infection
    • Old traumatic wounds >12h
    • Severe tissue damage and excessive ischemic tissue
    • e.g. abscess,perforated bowel
    • management healing by secondary intention
    • infection rate : 50%
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22
Q

10.Assessment of Wound Mechanism

A
  • Kinetic energy injury -closed -blunt
  • Kinetic energy injury-open-penetrating
    • low energy -knife
    • high energy - bullet
  • Thermal injury
    • Heat
    • Frost
  • Chemical injury
  • Electrical injury
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23
Q

11.Surgical Management of Wounds

A
  • Wound evaluation :
    • mechanism of injury
    • extent of injury and wound type
    • decision for wound closure
  • Patient consent
  • Antimicrobials : tetanus prophylaxis
  • Wound prep and sterile field
  • Anesthesia
  • Debridement-washing
  • Hemostasis
  • Closure
  • Dressing
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24
Q

12.Other skin closure options

A
  • Adhesive tapes
    • (+) rapid, simple, no risk of needle injury
    • (-) needs dry skin,poor adherence,poor hemostasis,accidental removal
  • Skin glue
    • (+) rapid,simple,reduced pain,good aethetic result
    • (-) poor approximation of deep layers,poor hemostasis
  • Surgical skin staples
    • (+) fast closure of large wounds,less rxn than sutures
    • (-) poor hemostasis
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25
13.Surgical instruments
* Cutting instruments * Scalpels * Scissors -for tissues and sutures * Grasping instruments * Tissue forceps * Ratcheted tissue forceps * Needle-holders * Retracting instruments * Hand-held retractors * Self-retaining retractors
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13.1.Surgical instruments
Surgical staplers * Skin stapler * Linear stapler * Gastrointestinal anastomosis stapler * Circular stapler
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13.2.Surgical Instruments
Energy applying instruments * Diathermy * Electrocoagulation * Monopolar- patient return electrode * Bipolar Other energy applying instruments * Mechanical energy (ultrasound scalpel) * Laser * Cyrotherapy * Radiofrequency needles
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13.3.Surgical Instruments
Sutures and Needles * Suture materials * Absorbable : polyglycolic acid,polydioxanone * Non absorbable : polypropylene,polyamide * Suture strand type * Monofilament * Multifilament * Twisted * Braided * Suture size : 10/0 - thinner than 1
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13.4.Surgical Instruments
Sutures and needles
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14.Local Anesthetics
* Inhibit electrical conduction along neurons * Transient blocking of Na+ transport channels in the cell membrane ⇒ blocks initial depolarization * sensory neurons are more sensitive than motor neurons * Lidocaine : 20mg/ml with or w/o adrenaline * Bupivacaine : 5mg/ml * Ropivacaine : 7.5 mg/ml * onset : 5-10 mins, duration 1-6 hrs
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14.Local Anesthetic Uses
* Topical * Lipid soluble cream * Extent of action :skin and mucosa up to few mm deep * Local infiltration * injected into tissue * local nerves * Nerve block * Injected around a nerve or plexus * Distribution of nerve blocked * IV block * IV injection in arterial tourniqueted limb * Nerve tissue within limb * Centrineural block * Epidural or spinal injection * Multiple dermatomes * Cavity administration * intrapleural or intraperitoneal admin * local nerves in cavity
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15.Local Anesthesia Toxicity
* Side effects * Mouth and tongue numbness * Anxiety * Tremor * Drowsiness * Tachypnea * Hypotension * Nausea & vomiting * Allergy
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16.Local infiltration anesthesia
* Lidocaine * time to onset : 5-10 min * dilution : 2% lidocaine - max dose 300 mg for a 70 kg person * #23 blue or #25 orange needle * infiltration technique : inject around site of incision
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17.Basic Surgical Skills
* Suturing * simple interrupted sutures * running (continuous) sutures * Knot tying * Incisions & excisions * elliptical excision : to take out a lesion * incision * Wound debridement * Hemostasis * with electrocoagulation * with ligature * Dissection * blunt dissection * sharp dissection
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18.Sterile Technique
* Sterile : all forms of microbial life destroyed * Aseptic : free from pathogens * Disinfection: process of destroying all pathogens * Clean : absence of gross contamination or dirt Principles 1. Reduction of env. contamination 2. Disinfection of procedural site 3. Isolation of procedural site 4. Sterilization of procedural tools
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19.Reduction of Environmental Contamination
* Clean OR staff * clean clothing * hair and beard covered * OR shoes * face mask * Clean hands * hand washing (scrub or hydroalcoholic rub) * Clean air * closed OR * laminar airflow * Clean equipment * no touching
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20.Disinfection of Procedural Site
* Cleaning * washing to remove macroscoping contamination * hair removal * painting skin with antibacterial solution * chlorohexidine 0.5%, povidone iodine 10%
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21.Isolation of Procedural Site
* Gowning and gloving * sterile gowns * sterile gloves - sometimes double gloving * no touch technique * Draping * exclusion of operative site w/ sterile towels or shet * two layers * raised sterile curtain btw anesthesist & surgeon
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22.Sterilization of procedural tools
* Steam: * Sterilization of all metallic instruments * Sterilization in packs * 20 PSI / 126C / 10 min * Autoclave, flash sterilizes * Dry heat: * 160C/ 1h * Chemical: * Gas (ethylene oxide) * Liquid (glutaraldehyde) - 10h soaking * Plasma (ionized hydrogen peroxide gas) * Sensitive equipment (endoscopes) : soaked in disinfectant
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23.Surgical Team Safety
Body fluids and substances * Risk of HBV,HCV,HIV * Avoidance of contact w/ mucosas and skin * Universal precautions Sharps and needles * Risk of injury from scalpels,needles * Handling,returning & handing over sharp instruments * Never recap needles * Never place sharps on pt * Protect needle point with needle holder Other hazards * Radiation exposure * Electrical shock from equipment * Toxic substances
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24.Patient Safety
Preparation for the procedure * Patient consent * Correct patient, correct operation,correct side - mark lesion * All lab and radiology tests available * Any pt allergies or important info known Positioning on operating table * No metal to skin contact * No pressure points * No abnormal traction or angulation of limbs * Mechanical DVT prophylaxis * Eyes taped shut to prevent drying * Stabilization of pt to avoid movement
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24.1.Patient Safety
Procedure * Injury from sharps * Injury from retractors * Electrocoagulation,lasers gauzes * Breach in sterile technique After procedure * Risk in transfer from the OR table (tube displacement, injury) * Post anesthetic observation
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25.Systemic Inflammatory Response Syndrome
* Inflammatory response to injury * Two or more of the criteria: * T ≥ 38oC or ≤ 36oC * HR ≥ 90/min * RR ≥ 20/min * WBC ≥ 12000/mm3 or ≤4000mm3 * Balance⇒Recovery * Proinflamatory phase (SIRS) * Counter - regulatory anti inflammatory response syndrome (CARS) * Mixed antagonist response syndrome * Imbalance ⇒ Multi Organ Failure (MOF)
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26.Sepsis and Septic shock
* Sepsis : Suspected documented infection + an acute increase of ≥ SOFA points * Septic shock : * Sepsis + persisting hypotension that requires vasopressors to maintain MAP of 65mmHg * Serum lactate level \> 2mmol/L (18mg/dL) despite adequate volume resussitation
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27.Sequential Organ Failure Assesment Score
46
28.Acute Phase Proteins
* Non-specific proteins secreted in response to tissue injury * Produced by liver * Biomarkers of systemic inflammation * **CRP** - normal \< 1 mg/dL * **Procalcitonin** - normal \< 0.15 ng/mL * IL-6
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29. CNS inflammatory regulation
Autonomic regulation of: * HR, BP,RR,GI motility * Body temp * Pro-inflammatory vs anti-infammatory response Afferent Signals * Inflammatory mediators * TNFa * Parasympathetic sensory input * Cytokines TNFa,IL-1 * Baroreceptors * Chemoreceptors * Thermoreceptors
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29.1 CNS inflammatory regulation
Cholinergic anti-inflammatory response * Ach receptors on tissue macrophages : Ach reduces tissue macrophage release of proinflammatory mediators * Ach reduces macrophage activation * Effect of PS on HR, Gı motility, arteriole dilation
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30.Hormonal Response to Injury
Pathways * Receptor kinases * G-protein receptors * Ligand gated ion channels ACTH- from anterior pituitary * glucocorticoid production Cortisol & Glucocorticoids - adrenal cortex * Hyperglycemia - release of FFA & TG from fat cells, immunosuppression, down-regulation of pro-inflammatory cytokines
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31.Inflammatory Mediators
* Cytokines * Heat shock proteins (protection from stress) * Oxygen radicals * Eicosanoids - endocrine,immune,vasomotor funct. * FA metabolites : attenuation of inflammatory resp. * Kallikrein-kinin sys : vasodilation, ↑ capillary permeability * Serotonin : vasoconstriction,bronchocons.,inotrope * Histamine : hypotension, ↑capillary permeability
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32.Endothelium mediated injury
* ↑ vascular permeability during inflammation * facilitate O2 delivery * facilitate immunocyte migration * ischemia reperfusion injury * accumulation of neutrophils * unleashing O2 metabolites,lysosomal enz * oxidation of basal membranes * microvascular thromboses * Endothelium hypoxia,endotoxins,injury and sheer stress produce * NO -smooth m relaxation * Prostacyclin - vasodilation & platelet activa. * Endothelins - most potent vasoconstrictor * Platelet-activ factor - activates neut,platelets - ↑ vascular permeability * Atrial Natriuretic Peptides -vasodilation,fluid & electrolyte secretion, aldosterone inhibitors
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33. Causes of Fluid and electrolyte imbalance
* Surgical trauma - sepsis * 3rd space fluid isolation * Peri-operative fasting * Vomiting * Diarrhea
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34.Body Water
* Total body water = 50-60% of total body weight * Tissue water concentration * Muscle-solid organs \> fat * New born\>adult\>elderly * Male\>female * Lean\>obese
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35.Fluid Compartments
* Intracellular fluid : 40% of total body weight * K+ : 150mM , Na+: 15mM, Mg2+: 40mM, Ca2+: minimal * Phosphates,sulfates:150mM,HCO3- : 10mM, proteins : 40mM * Extracellular fluid : 20% of total body weight * Interstitial fluid 15% * Plasma 5% * Na+ : 142mM, K+: 5mM,Ca2+: 5mM,Mg2+:2mM * Cl-:103mM,HCO3- : 26 mM,Phosphates: 2mM,Sulfates :1mM, Proteins: 17 mM
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36.Body Fluid Osmolality
* Total solute concentration : mOsm/kg * 290-310 mOsm/kg * water diffuses freely between compartments
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37.Fluid Sodium
* Sodium is confined to ECF * Sodium containing fluids * expansion of intravascular space - 5% * 3x expansion of interstitial space - 15%
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38. Daily solute balance
* Oral intake : 2000 mL * Cell metabolism : 400 mL * Urinary excretion: 1500 mL * Stool: 200 mL * Skin,Lungs: 600 mL
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39.Fluid Volume & Osmolality Control
* Baroreceptors * Pressure sensors in aortic arch & carotid sinuses * Osmoreceptors * Sensors that detect changes in osmolality,kidney * Hypothalamus⇒vasopressin ⇒renin-angiotensin-aldosterone⇒atrial natriuretic peptide⇒reduction in expanded ECF
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40.Body Fluid Disturbances
* Volume disturbances * Volume deficit * Volume excess * Electrolyte concentration disturbances * Acid-base imbalance
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41.Extracellular Volume Deficit
Causes in surgical patients: * Inability to ingest water * Loss of GI fluids : * Nasogastric tube suction * vomiting * diarrhea * enterocutaneous fistula * Fluid isolation * soft tissue injuries * burns * peritonitis-sepsis * ileus-obstruction
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41.1.Extracellular Volume Deficit
Clinical observations * Weight loss 1kg/1L * ↓ skin turgor * Sunken eyes * Tachycardia * Hypotension * Oliguria * Confusion Lab exam: * ↑BUN,↓GFR * ↑BUN: Creatine ratio * ↑Hematocrite * ↑urine osmolality (higher than serum) * ↓urine sodium (20mEq/L)
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42.Extracellular Volume Excess
Causes: * Iatrogenic * Renal dysfunction * Heart failure * Cirrhosis * Inappropriate secretion of antidiuretic hormone Clinical observations: * Weight gain * Peripheral edema- limb swelling * ↑central venous pressure * distended jugular veins * pulmonary edema - fine crackles * cardiac insufficiency - gallop rhythm Lab exams: * ↓ hematocrite * ↓ urine osmolality
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43.Electrolyte Disturbances Sodium
* Na+ : predominant electrolyte of ECF * Na+ concentration influences fluid osmolality * Changes in Na+ are inversely proportional to total body weight * Serum Na+ : 135-145 mEq/L **Hypernatremia** * causes: * high volume * gain of Na+ in excess of water * hyperaldosteronism,cushing syndrome * normal or low volume * loss of free water (renal,GI tract,DI)
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43.1.Electrolyte Disturbances Sodium
Clinical Observations of Hypernatremia * Thirst * If Na+ concentration \> 160mEq/L * Cellular dehydration - extracellular water shifting * CNS symptoms - restlessness,irritability,seizures,coma * Musculoskeletal - weakness * If hypovolemic hypernatremia * Tachycardia * Orthostatic hypotension Lab exams : serum Na+ \> 145 mEq/L severe if \> 160, urine specific gravity SG \> 1.030 if nonrenal water loss
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43.2. Electrolyte Disturbances Sodium
**Hyponatremia** Causes: * Dilution * Iatrogenic * Polydipsia (psychogenic,DM, DI) * Severe hyperglucemia (glc osmosis) * Secretion of ADH (post trauma,surgery) * Drugs (ACEI,antipsychotics) * Depletion * Low Na+ diet * GI losses (vomiting,nasogastric suction) * Renal losses (diuretics,renal diseases)
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43.3.Electrolyte Disturbances Sodium
Clinical observations of hyponatremia * If severe - \< 120 mEq/L * CNS - seizures, coma,↑intracranial pressure * Musculoskeletal - weakness,fatigue,cramps * Rapid correction of severe hyponatremia⇒ osmotic demyelination syndrome Lab exams: * Serum Na+ \< 135 mEq/L * Low urine Na+ concentration \< 20 mEq/L if extrarenal losses * High urine Na+ concentration \> 20 mEq/L if renal losses
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44.Electrolyte Disturbances Potassium
* Predominant intracellular cation * Only 2% of total body K+ is extracellular while 98% is intracellular * Critical to cardiac and neuromuscular function * Serum K+ : 3.5-5 mEq/L **Hyperkalemia** : K+ \> 5mEq/L Causes: * Excesive K+ intake - supplements, blood transfuse * Cell destruction - hemolysis,crush injury * K+ extracellular shifting - acidosis * Impaired kidney K+ secretion -K sparing diuretics,renal insufficiency
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44.1.Electrolyte Disturbances Potassium
Clinical Observations of hyperkalemia * GI - nausea,vomiting,colic * Neuromuscular - weakness,paralysis * Cardiovascular - arrythmia,arrest ECG alterations * Peaked T waves, flattened P wave * Prolonged PR interval * Widened QRS * V-fib
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44.2.Electrolyte Disturbances Potassium
**Hypokalemia** : K+ \< 3.5 mEq/L Causes: * ↓ intake - inadequate oral or iv K+ * Intracellular K+ shifting - alkalosis * Excessive K+ renal excretion - diuretics,hyperaldosteronism * GI losses - diarrhea,vomiting,fistula
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44.3.Electrolyte Disturbances Potassium
Clinical observations of hypokalemia * GI- ileus,constipation * Neuromuscular-↓reflexes,fatigue,weakness,paralysis * Cardiovascular-PEA,asystole ECG alterations * U waves * T-wave flattening * Arrythmias
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45.Electrolyte Disturbances Calcium
* contained in bone matrix 99% * serum calcium - 50% ionized (free) and 50% bound (protein & phosphate complexes) * total serum Ca2+ is measured but the ionized is responsible for neuromuscular stability **Hypercalcemia** Causes: * primary hyperparathyroidism * malignancy - bone metastases,secretion of PTH related protein Clinical observations * GI - nausea,vomiting,abdominal pain * Neuromuscular - weakness,confusion,coma,pain * CV- hypertension,arrythmia,ECG alterations
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45.1.Electrolyte Disturbances Calcium
**Hypocalcemia** : Ca2+\< 8.5 mEq/L Causes: * Hypoparathyroidism * Other - pancreatitis,renal failure Clinical observations: * In severe hypocalcemia * Neuromuscular - hypereflexia,tetany,Chvostek's sign (spasm of facial m. when facial n is tapped at lvl of jaw),Trousseau's sign (carpal spasm induced by BP cuff), bone pain * CV - heart failure, ECG alterations
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46.Electrolyte Disturbances Magnesium
* Predominantly intracellular * 1/3 serum Mg is albumin bound * Normal serum Mg2+ = 1.5-2.5 mg/dL **Hypermagnesemia** Causes: * Excess intake - Mg laxatives and antacids * Renal failure Clinical observations * GI - nausea,vomiting * Neuromuscular- weakness,vomiting, ↓reflexes * CV-hypotension,arrest,ECG alterations like hyper-K
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46.1.Electrolyte Disturbances Magnesium
**Hypomagnesemia** : Mg2+ \< 1.5 mg/dL Causes: * common in hospitalized patients * poor intake * ↑ renal excretion - alcohol, diuretics * GI losses - diarrhea * acidosis Clinical observations * Neuromuscular - hyperactive reflexes,tremors,tetany,seizures * CV - ECG alterations-torsade de pointes,arrest * can produce hypocalcemia * can cause persistent hypokalemia
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47.Electrolyte Disturbances Phosphorus
* primarily a constituent of bone * predominant intracellular anion HPO43- * abundant in metabolic active cells : high energy phosphate products (ATP) * controlled by urinary secretion * serum phosphorus : 2.5-4.5 mg/dL **Hyperphosphatemia** : P-3 \> 4.5 mg/dL Causes * ↓ urinary excretion * ↑ intake - phosphorus rich laxatives * ↑ production- cell destruction Clinical observations * asymptomatic * high calcium-phosphate product⇒calcifications
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47.1.Electrolyte Disturbances Phosphorus
**Hypophosphatemia** : P-3 \< 2.5 mg/dL Causes: * poor dietary intake - alcoholism * antacid administration- binding of P in bowel * hyperparathyroidism Clinical observations: * When severe hypo-p \<1 mg/dL * Neuromuscular - fatigue,weakness,convulsions * CV- impaired heart contractibility * Osteomalakia-chronic depletion
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48.Acid Base Balance
* Daily metabolism produces 1 mEq/kg of H+ * Produced CO2 is transformed to H2CO3 * Buffering systems * intracellular proteins- hemoglobin * extracellular bicarbonate/carbonic acid H++HCO3- ⇔ H2CO4⇔H2O +CO2 pH = pK + log ( [HCO3- ] / 003 x PCO2 * PCO2 ⇒ regulated by **pulmonary ventilation** * HCO3- is regulated by the **kidney** * HCO3- reabsorption * Secretion of H+ * Secretion of NH4+
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49.Normal Values
* pH is regulated at 7.35-7.45 * Acidemia ⇒ pH \< 7.35 * Alkalemia ⇒ pH \> 7.45 * HCO3- : 22-26 mmol/L * PCO2 : 35-45 mmHg Anion gap * UA-UC = [Na+] - ( [HCO3-] +[Cl-]) : 3-11 mEq/L
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50.Respiratory Acidosis
* PCO2 \> 45 mmHg Acute respiratory acidosis * Acute respiratory failure - obstruction,aspiration * PCO2 ↑ * HCO3- stable * pH↓ - acidemia Chronic respiratory acidosis * Chronic respiratory failure * PCO2 ↑ * HCO3- ↑ - compensation - renal NH4 excretion * pH normalized
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51.Respiratory Alkalosis
* PCO2 \< 35 mmHg Acute respiratory alkalosis * Acute hyperventilation - psychogenic,sepsis * PCO2 ↓ * HCO3- stable * pH ↑ - alkalemia Chronic respiratory alkalosis * PCO2↑ * HCO3- ↑ * pH normalized
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52. Metabolic Acidosis
* HCO3- \< 22 mmol/L * Excessive HCO3- - diarrhea, diuretics * HCO3- ↓ * Cl- ↑ * Anion gap is normal N = 3-11 mEq/L * hyperchloremic metabolic acidosis * Excessive lactate,acetoacetate,b-hydroxybutyrate * Addition of unmeasured anions * Anion gap is ↑ * HCO3- ↓ - consumption
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53.Metabolic Alkalosis
* HCO3- \> 26 mmol/L * Causes * Loss of H+ ⇒ ↑ in HCO3- (vomiting,ng suction) * Impaireed renal exertion of HCO3- * Associated hyperchloremia * Volume depletion
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54.Respiratory & Metabolic Components of Acid-Base Disorders
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55.Principles of Fluid & Electrolyte Therapy
* Surgical patients need fluids * None by mouth ⇒ IV * Maintenance of fluids * Volume replacement * Bleeding * Sepsis * GI losses * Evaluation of the fluid volume deficit * Calculation of ongoing fluid losses * Assessment of Na+,K+ requirements * Management of acid-base disturbances
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56.Volume and Electrolyte Content of GI Fluids
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57.Types of Replacement Fluids
**Crystaloids** * Solutions of water w/ electrolytes * Solutions of water w/ glucose **Colloids** * Solutions of high molecular weight macromolecules
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58.Parenteral Electrolyte Solutions Crystaloids
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59.Parenteral Electrolyte Solutions Colloids
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60. Replacement Fluid Guidelines
* Maintenance fluids : 30-40 ml /kg/day * Replace all losses volume for volume * Isotonic vs hypotonic vs hypertonic * No K+ for the early post-operative period Infused fluids distribution * Glc solutions ⇒ 2/3 intracellular , 1/3 extracellular * Na+ solutions ⇒ 1/4 intravascular, 3/4 interstitial * Colloids⇒ intravascular space
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61. ASA Physical Status Classification
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62. Altered State Patient
Nutritional Assessment * Anticipated post-operative fasting * Dietary history * Weight loss \> 10% * Serum albumin \< 3 g/dL, transferrin \< 150 mg/dL Immune incompetence * Elderly patients, malnutrition,cancer,severe burns * Total lymphocyte count * Skin tests (anergy) Infectious risk * Drugs : corticosteroids, immunosuppressors,cytotoxic drugs, prolonged antibiotic therapy * Renal failure * Granulocytopenia * Hematologic diseases: lymphomas,leukemias,hypogammaglobulinemia * Uncontrolled diabetes
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63.Patient with Pulmonary Dysfunction
* Risk of post-operative complications : hypoxia,atelectasis,pneumonia History * Heavy smoking \>20 PY * Cough - character sputum,Wheezing * Exercise intolerance * Obesity * Old age * Known pulmonary disease Physical exam * Wheezing, prolonged expiration Lab tests * Chest x-ray, ECG * Arterial blood gases - CO2 retention - respiratory acidosis, pulmonary function tests - FVC,FEV1
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64.Delayed wound healing
Patient at risk * Hypoproteinemia * Vit C deficit * Volume disorders - edema/dehydration * Anemia * Diabetes * Smoking * Corticosteroids- in large doses * Cytotoxic chemotherapy * Irridation
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65.Drug effect
Drug allergies * Penicillin/antibiotics * Morphine/opioids * Xylocaine-local anesthetics * Aspirin/NSAIDS * Tetanus antitoxin * Iodine-other antiseptics * Other drugs,Food,Adhesive tape Drug adaptation * Digitalis,insulin,corticosteroids⇒continuation * stress dose of corticosteroids- hydrocortisone 100 mg x3 * Oral anticoagulation drugs replaced w/heparin * Oral antidiabetics replaced w/ insulin during fasting * CNS depressants - barbiturates,opioids,alcohol,chlorpromazine * Antihypertensives
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66.Patient at Risk of Thromboembolism
Patient risk factors * Cancer * Obesity * MI * Age \>45 * History of thromboembolic event Surgery * General,pelvic,orthopedic surgery DVT prevention * Early postoperative mobilisation * Mechanical : graduated compression stockings,intermittent pneumatic compression * Chemical : unfractioned heparin,low molecular weight heparin
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67.Elderly Patients
Physiological vs chronological age * CV,renal,other systemic diseases Patients \> 60 * Arteriosclerosis * Cardiac reserve limitation * Renal reserve limitation * Occult cancer Avoid volume overload * fluid intake and output * body weight * CVP Adapted doses of drugs * Narcotics * Benzos can cause agitation
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68.The Obese Patient
Metabolic Syndrome * ↑BP, ↑ blood sugar lvl, ↑↑↑ body fat around waist, abnormal cholesterol levels Risk of concominant disease * Heart disease * Stroke * Diabetes Wound complications
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69.Preoperative Patient Preparation
* Preoperative hyperalimentation (7-10d) * Pulmonary prep for \> 48h * Abstinence from smoking * Inhaled bronchodilators * Chest physical therapy x2 a day * Inspiratory effort exercise devices * Maintain blood volume and tissue perfusion * Avoid dehydration/volume deficit * Drug adaptation * Thromboembolic prophylaxis * Fasting for 6h (solids) & 2h (liquids) before major operations or general anesthesia
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70.Preoperative Formalities
* Patient info * Surgeon * Diagnosis * Planned surgical procedure * Risks & possible complications * Need for blood transfusion * Postoperative recovery * Anesthesiologist * Type of anesthesia * Anesthesia related risks * Postanesthesia recovery * Signed informed consent * Signed by pt or legal guardian of minors * Emergency lifesaving operations
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71.Operative Field Preparation
Initial prep- evening before operation * Washing w/ soap and water * No shaving - ↑ skin infection risk * Marking of operative site by surgeon In operating room * Hair clipping if required * Skin prep w/ 2% iodine in 90% alcohol - for \> 1 min, avoid using in perineum,genitelia,face,avoid spilling outside operative field * Universal precautions * Barrier protections * Avoid accidental injuries * Avoid contact of open wounds w/ pt * Check gloves for tears
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72.Control of Hospital Cross-Infections
Surgical infection control program * Target of \< 1% of clean wond infection rate * Cultures and antibiotic sensitivity on all infections * Isolation of pt w/ communicable infections * Aseptic technique * Isolation of OR * Dressing of open wounds * Hand washing * Antibioprophylaxis * For clean-contaminated & contaminated cases * For clean cases if implanted material * Give 1h to 30 min before incision * 2nd gen cephalosporin,single dose. Repeat after 4h of surgery or major blood loss
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73.Immediate Post-operative - Post-anesthetic Phase
Postanesthesia Care Unit * Monitoring for 1-3 hrs post-op * Discharge when cv,pulmonary & neurological functions normalized Discharge w/ written post-op orders to * Ward * ICU /High dependency unit
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74.Post-operative orders
* Monitoring * Vitals * ECG monitor * CVP,PCWP * Fluid input/output * Respiratory care * Position in bed and mobilization * pt turned every 30 min til conscious * change position every 1h for first 8-12h * early mobilization * Diet,Fluids & electrolytes, * Medications : analgesics,dvt prophylaxis,gastric acid suppression etc * Lab & imaging exams
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75.Intermediate Postoperative Period
After complete recovery from anesthesia & transfer to ward * Wound care * Keep wound covered w/ sterile dressings for 2-3d post-op * Soaked dressings replaced * Dressing replacement on first 24h should be done w/ aseptic technique * By 48h after closure, the skin wounds is sealed off from external env
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75.1.Intermediate Postoperative Period
* Management of drains * Prevent contamination of drain tract * Handling of the drain w/ asceptic technique * Early drain removal * Post-op care of GI tract * GI tract peristalsis return to normal after laparatomy : * Small bowel w/in 24h * Right colon after 48h * Left colon after 72h * Early normal feeding/enteral feeding
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75.2.Intermediate Postoperative Period
Post-op pain control * Parenteral opioids * ↓ risk of addiction * side effects : respiratory depression, nausea, vomiting, paralytic ileus * NSAIDs * side effects : GI ulcers, impaired coagulation, reduced renal function * Paracetamol * Patient controlled analgesia * Continuous epidural analgesia * Nerve blocks
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76.Postoperative Complications
* Every complication that appears after operation * May result from 1o disease, the operation, comorbidities, or unrelated factors * Early detection * Pre-op identification or risks & pt optimization
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76.1.1.Postoperative Complications Classification Systems
* Grade I : * any deviation from normal post-op course w/out need for pharma treatment, or surgical endoscopic and radiological interventions * Grade II: * Requiring treatment w/ drugs other than such allowed for grade I complications. * Grade III: * Requires surgical,endoscopic or radiological intervention * Grade IV: * Life threatening complications (including CNS) requiring ICU-management * Grade V: * Death of patient
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76.1.2.Postoperative Complications Wound Complications
Seroma * Fluid collection other than pus or blood * After lymphatic transection * Delay healing, infection risk * Treatment: watchful wait, needle aspiration, compression dressing Hematoma * Collection of blood & clot * Imperfect hemostasis * Discomfort, compression effect, infection risk * Risk factors: anticoagulants, aspirin, marked HT * Treatment: evacuation of blood clot under sterile conditions & hemostasis
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76.1.3.Postoperative Complications Wound care
Surgical site infection * Bacterial infection w/ inflammation and/or purulent collection * Breach of aseptic conditions or operative contamination * Risk factors: pt factors vs operation related factors * Treatment: wound exploration/drainage, cultures, antibiotics Pain * Controlled by analgesics * Pain ↓ on first 4-6 post-op days * Persistent pain needs exploration - abcess, granuloma, incisional hernia
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76.1.4.Postoperative Complications Wound Complications
Ascitic leak * Risk of wound infection and peritonitis * Treatment: wound exploration (OR) & fascia closure Wound dehiscence * Partial & total disruption of any or all layers of wound * Systemic vs. local factors * Between 5-8 post-op days * Discharge of serosanguineous fluid * Dehiscence of laparatomy ⇒ evisceration * Treatment: wound covered w/ moist towels, abdominal closure in OR
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76.1.5.Postoperative Complications Respiratory Complications
Atelectasis * Bronchiole closure &/or obstruction from secretions * Risk factors: old age, smoking, obesity, abdominal operations * Diagnosis: fever, tachypnea, tachycardia, chest x-ray * Atelectatic segments - risk of infection (pneumonia) * Prevention: early mobilization, frequent changes in position, coughing, incentive spirometer * Treatment: chest percussion,nasotracheal suction,bronchodilators,mucolytics
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76.1.6.Postoperative Complications Respiratory Complications
Pulmonary Aspiration * Risk factors: NG tube, CNS depression, gastroesophageal reflux, intestinal obstruction, pregnancy, trauma patients * Diagnosis: tachypnea, rales, hypoxia, cyanosis, wheezing * Causes chemical pneumonitis & is a major risk of pneumonia * Treatment: endotracheal suction, bronchoscopy, fluid resuscitation, antibiotics
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76.1.7.Postoperative Complications Respiratory Complications
Post-op pneumonia * Risk factors: intubation, atelectasis, aspiration, bronchial secretions * Microbes: g (-) bacilli, pseudomonas aeruginosa, klebsiella * Mortality : 20-40% * Treatment : Clearing of secretions, sputum cultures, antibiotics
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76.1.8.Postoperative Complications Respiratory Complications
Pleural effusion * After upper abdominal operations, cardiac failure, pulmonary lesion, subdiaphragmatic inflammation * Treatment: watchful wait, aspiration,drainage Pneumothorax * After pleural injury or positive pressure ventilation * Treatment: thoracostomy tube
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76.1.9. Postoperative Complications Respiratory Complications
Cardiac complications * Cardiac arrythmias * due to reversible factors (hypo-K, hypoxia, acidosis, stress, drug toxicity) * Pt w/ preexisting arrythmias * Post-op MI * 1/2 post-op MI are asymptomatic * Postponing elective operations for 6 mo after MI * Predisposing factors: hypoxia, hypotension, stress * Post-op cardiac failure * Left ventricular failure & acute pulmonary edema * Predisposing factors: cardiac arrythmia, MI, volume overload, sepsis
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76.2.Postoperative Complications Peritoneal Complications
Hemoperitoneum * W/in 24h of the operation * Tachycardia, hypotension, peripheral vasoconstriction, oliguria * Changes in Hct and Hg seen after 4-6h * Radiological imaging - US, CT * Patient stabilization, surgical treatment
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76.2.1. Postoperative Complications Complications of Drains
* Risk of drain tract infection * Drain displacement * Bleeding from drain tract * Pain
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76.2.2.Postoperative Complications GI Motility Complications
Prolonged paralytic ileus * Return of GI motility w/in 24h after non-abdominal surgery * After laparotomy return of GI motility w/in 48h * Paralytic ileus can last up to 5 post-op days * No specific therapy Bowel Obstruction * From post-op adhesions or internal hernia * Surgical treatment
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76.2.3.Postoperatie Complications GI Motility Complications
Gastric Dilation/Gastroparesis * Massive distention of the stomach by fluid & gas * Abdominal pain, distention and hiccups * Risk of inhalation * Gastric decompression w/ ng tube Fecal Impaction * Aggravating factors: opioids, anticholinergics, paralytic ileus * Digital extraction, enemas
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76.2.4.Postoperative Complications Anastomotic Leak
* Healing failure of an intestinal anastomosis * Usually 3-8d after surgery - up to 1 month * Peritonitis: acute abdominal pain w/ rigid abdomen, tachycardia, high fevers & often hemodynamic instability * Abscess: insidious presentation : low grade fever, prolonged ileus or failure to thrive * Treatment options: surgical treatment, percutaneous drainage
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76.2.5.Postoperative Complications Liver and Pancreas Complications
Hepatic dysfunction * Prehepatic jaundice * Hemolysis * Reabsorption of hematomas * Hepatocellular insufficiency * Hepatic cell necrosis (drugs, hypotension, hypoxia, sepsis) * Massive liver resection * After prolonged total parenteral nutrition * Posthepatic obstruction * Injury to the CBD * Retained CBD stones
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76.2.6.Postoperative Complications Liver & Pancreas Complications
Postoperative cholecystitis * Acalculous cholecystitis⇒risk of necrosis * After ERCP-Endoscopic Retrograde Cholangiopancreatography * After embolization of the right hepatic artery Postoperative pancreatitis * After operations in the vicinity of pancreas * Mechanical trauma to the pancreas or its blood supply * Drug induced pancreatitis (theiaazides, azathioprin, valproic acid)
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76.2.7.Postoperative Complications Clostridium Difficile Colitis
* Post-op diarrhea - pseudomembranous colitis * From mild diarrhea to severe toxic colitis * Diagnosis by IDing the toxin in the stool, bacteriology, endoscopy * Prevention: hygiene, minimizing antibiotic use * Treatment: metronidazole, vancomycin, fecal transplantation
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76.2.8.Postoperative Complications Urinary Complications
Urinary retention * Interference w/ neural mechanism of micturition * Bladder overdistention \< 500ml * Catheterization for operations longer than 3h, pelvic operations * Encourage preoperative urination & soon after UTIs * Most frequent nosocomial infection * Risk factors: catheter, urinary retention * Cystitis, pyelonephritis * Treatment: hydration, antibiotics
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76.2.9.Postoperative Complications IV and intraarterial catheters
Air embolism * Accidental insertion of air in a central venous catheter * Acute dyspnea, tachypnea, continuous cough, gasp reflex, neurological symptoms * Position pt head down, right side up to trap air in right ventricle- supportive measures Ischemic necrosis of fingers * Ischemia due to indwelling radial artery catheter * Patency of ulnar artery (Allen's test) * Early removal of arterial catheter
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76.3.Postoperative Complications IV and intraarterial catheters
Thrombophlebitis * Common cause of fever * Induration, edema, tenderness * Prevention: aseptic technique, change of tubing, rotation of insertion site
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76.3.1.Postoperative Complications CNS & Psychiatric Complications
Postoperative stroke * Due to poor cerebral perfusion-abrupt hypotension * After carotid endarterectomy, open heart surgery w/ extracorporeal circulation Delirium tremens * Due to abrupt alcohol withdrawal w/in 2 weeks * Personality changes, restlessness, confusion, overactivity, seizures * Treatment: small amounts of alcohol, benzos
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76.3.2.Postoperative Complications CNS & Psychiatric Complications
Postoperative psychosis * Elderly pt, severe systematic disease * Present mood disturbances, confusion, fear, disorientation, delirium * May be drug related: cimetidine, corticosteroids, benzos * Eliminate metabolic derangements and early sepsis ICU syndrome * Due to pain, fear, sleep deprivation from bright lights * Impaired cognitive ability, confusion, halucinations, delirium
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76.3.3.Postoperative Complications Postoperative Fever
* Post-op temperature elevation in 40% of pt * w/in 48h * After 2nd day : thrombophlebitis, pneumonia, UTI * After 5d: Surgical site infection, anastomotic leak * After 1w: Allergy, transfusion, sepsis, intraabdominal abscess
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77.Shock
* Presence of tissue hypoperfusion that is insufficient to maintain normal aerobic metabolism * Provokes sympathetic/paras & neuroendocrine stress response * Leads to tissue hypoxia & end-organ dysfunction * ↑ cardiac contractility & peripheral vascular tone * hormonal response to preserve salt & intravascular fluid * changes in microcirculation to regulate blood flow * Persistent hypoperfusion w/ ↓ CO induce CV decompensation⇒ irreversible phase of shock, irreversible tissue injury and cell death
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78.Neuroendocrine Response to Shock
Afferent signals to CNS * Pain, infection, temp, hypoglycemia, emotional stress * Volume receptors : heart atria * Baroreceptors: aortic arch, carotid bodies * Chemoreceptors: aorta, carotid bodies Efferent signals to CNS * CV response: ↑HR(B1),↑H.contractility(B1),Arterial vasoconstriction(a1) * Hormone response: * ACTH⇒cortisol * Renin-angiotensin⇒aldosterone * ADH
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78.1.Neuroendocrine Response to Shock
Microcirculation * Vasoconstriction of arteries & larger arterioles (a1) * Vasodilation of distal arterioles (local factors) * Diminished capillary hydrostatic pressure * Shifting of fluid from EC space inside capillaries * Capillary occlusion from endothelium cell swelling & neutrophil sludging * Changes of microcirculation blood flow btw & w/in systems
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79.Cellular Response to Shock
Oxygen tissue lvl ↓ * Mitochondrial dysoxia * Anaerobic cell meetabolism (lactate production) * Lactic acidosis * Intracellular acidosis Cellular ATP depletion * Na+,K+, ATPase activity ↓ * Intracellular Na+ accumulation * Cellular edema * ↓ of cell membrane resting potential Apoptosis
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80.Immune & Inflammatory Response to Shock
Pro-inflammatory components * TNFa * By monocytes, macrophages, T-cells * Induction of septic shock * Peripheral vasodilation, pr breakdown, procoagulation * IL-1B * Half life of 6min * Febrile response, anorexia * IL-2 * By activated T-cells * Activates lymphocytes * Shock induced tissue injury
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80.1.Immue & Inflammatory Response to Shock
* IL-6 * Causes lung, liver & gut injury after hemorrhagic shock * Enhances activity of CRP, fibrogen, complement, neutrophil activation * IL-10 * Immunosuppressive properties * By T-cells, monocytes, macrophages * Depression of cytocine production, oxygen radical production, adhesion * IL-4
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81.Forms of Shock Hemorrhagic Shock (hypovolemic)
* Loss of circulating volume from hemorrhage * Sym activation⇒ vasoconstriction * Renin-angiotensin-aldosterone activation⇒urinary Na+ and fluid retention * ADH secretion⇒cerebral & coronary vessel autoregulation Diagnosis: * Capillary refill time \>2sec * Weak peripheral pulse * Cold & clammy extremities Treatment : * secure airway & ventilation * Hemorrhage control * Fluid resuscitation
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81.1.Forms of Shock Cardiogenic Shock
* Circulatory pump failure ⇒tissue hypoxia in setting of adequate intravascular volume * Hemodynamic criteria * SBP \< 90 mHg for more than 30 min * Cardiac index \< 2.2L/min/m2 * PCWP \> 15mmHg * Causes: * Acute MI * End-stage cardiomyopathy * Myocarditis * Valvular disease - aortic stenosis, mitral stenosis * Mortality : 50-80%
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81.1.2.Forms of Shock Cardiogenic Shock
Diagnosis * Signs of shock * Physical exam * cardiac murmur/sounds * arrythmia * acute pulmonary edema * ECG * Chest x-ray * Heart ultrasound * Invasive heart monitoring * CVP * PCWP
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81.1.3.Forms of Shock Cardiogenic Shock
Treatment * Secure airway & ventilation * Exclude hypovolemia * Correction of electrolyte imbalance * Inotropic support * Dobutamine * Dopamine * Epinephrine * Intra-aortic balloon pump * Treatment of underlying disease * PTCA +/- stent for acute MI * Heart transplantation
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81.1.4.Forms of Shock Septic Shock
Vasodilatatory shock = failure of vascular smooth muscles to contract * septic shock * hypoxic lactic acidosis * carbon monoxide poisoning * terminal stage shock of any cause Pathophysiology * Derailment of SIRS ⇒vasodilation & hypotension⇒ ↑catecholamines,↑CO⇒R-A-Al activation ⇒ upregulation of iNOS in vessel wall
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81.1.5.Forms of Shock Septic Shock
Diagnostic criteria * SIRS * T \> 38oC or \< 36oC * HR \> 90/min * RR \> 20/min or PCO2 \< 32 mmHg * WBC \> 12000/mm3 or \< 4000/mm3 or bands \> 10% * Sepsis : SIRS + infection * Septic shock : sepsis + tissue hypoperfusion * SAP \< 90 mmHg * MAP \< 65 mmHg * SAP ↓ \> 40 mmHg from baseline * Lactate \> 4 mmol/L
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81.1.6.Forms of Shock Septic Shock
Treatment * Secure airway & ventilation * Early hemodynamic optimization -6h * Fluid resuscitation * Vasopressors * Infection control * cultures * antibiotics * surgical source control * Glycaemia control * Immune modulation * Activated protein C * Cortisol
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81.1.7. Forms of Shock Neurogenic Shock
* Shock due to loss of vasomotor tone to peripheral arterial beds * Cause: spinal corn injury or ischemia Diagnosis * ↓BP, bradycardia * warm extremities * motor and sensory deficit * Radiographic evidence of spinal cord fracture Treatment * Secure airway & ventilation * Fluid resuscitation * Vasopressors : dopamine and phenylephrine (a-agonist)
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81.1.8.Forms of Shock Obstructive Shock
* Due to mechanical obstruction of venous return * ↓ filling of right atrium (tension pneumothorax) ⇒ ↓ preload (cardiac temponade) Diagnosis : * Respiratory distress * Hypotension * Ipsilateral ↓ breath sounds * Hyperresonance to percussion * Tracheal deviation * Distended jugular veins Treatment : needle paracentesis, tube thoracostomy
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81.1.9.Forms of Shock Obstructive Shock
Cardiac temponade Diagnosis * High index of suspicion - injury mechanism * Dyspnea * Tachycardia & hypotension * Chest pain * Muffled heart sounds * Distended jugular veins/ ↑ CVP * Chest x-ray * Echocardiography Treatment: needle pericardiocentesis, left thoracotomy &pericardial window
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81.2.Forms of Shock Traumatic Shock
Systemic response after trauma * Mechanism * Soft tissue injury * Long bone fracture * Blood loss * Pathophysiology * Pro-inflammatory activation * High incidence of ARDS * Treatment * Hemorrhage control * Volume resuscitation * Stabilization of fractures & treatment of soft tissue injuries
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82.Endpoints Resuscitation
* Goal in treatment of shock : restoration of adequate organ perfusion & tissue oxygenation * Endpoints for resuscitation * O2 transport * Lactate * Base deficit * Gastric tonometry * Near infrared spectroscopy * Tissue pH, O2,CO2 * Right ventricular and diastolic index
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83.Fluid Resuscitation
Crystalloids vs Colloids * Crystaloids more used, cheaper, better results in trauma patients Albumin infusion : detrimental * ↑mortality in hypovolemia, burns, hypoalbuminemia Hypertonic saline (NaCl 7.5%) * Outcomes of hemorrhagic shock : immunomodulation, intracellular liquid shifting Blood transfusion trigger * Hg 7-9 g/dL , Hg 10-12 g/dL for pt w/ cardiac disease Hypotensive resuscitation * Penetrating injury : SBP 80-90 mmHg * Blunt trauma: SBP 110 mmHg
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84.Nutritional Assessment History
* Factors predisposing to malnutrition * Absorption disorders (celiac sprue) * AIDS * Alcoholism * Chronic renal insufficiency * Cirrhosis * DM * Enteric obstruction * IBS * Malignancy * Prolonged starvation * Psychiatric disorders * Recent major surgery,trauma or burn * Surgical operations of GI tract * Severe cardiopulmonary disease
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84.1.Nutritional Assessment Physical Examination
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84.2.Nutritional Assessment Lab tests
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85.Nutritional Indices
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86.Calculating Daily Energy Requirements
Basal Energy Expenditure BEE(male) = 66.4 + [13.7 x weight in kg] + [5xheight in cm] - [6.8 x age] BEE(female)= 655 + [9.6 x weight in kg] + [1.7xheight in cm] - [4.7 x age] TEE = BEE x stress factor (1-1.8) kcal/day
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87.Metabolism Energy Requirements
* Basal Metabolic Rate - 60% of TEE * 50% ion pumping * 30% pr metabolism * 20% aa,glc,lactate &pyruvate metabolism * Physical activity - 30% of TEE * 10-50% for normal subjects * 10-20% for hospitalized pts * Thermic Effect of Food - 10% of TEE * Energy expanded for digestion,absorption & metabolism of nutrients
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88.Nutrient Requirements Carbohydrates
* 1o energy source * 30-40% of total caloric intake * 4 kcal/g * Digestion: * salivary & pancreatic amylase * absorption by first 1-1.5m of small bowel * Min. intake of 400 kcal of CHOs / day minimizes pr takedown * Glc necessary for hemopoietic system & CNS
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88.1.Nutrient Requirements Proteins
* Composed of 20aas * 4 kcal/g of pr * Digestion * gastric peptin * pancreatic proteases * absorption at duodenum - 50% and mid-jejenum * Protein turnover * Total body pr 10-11 kg in a 70 kg person * Daily pr turnover 250-300g * Requirements : 0.8/kg body weight/day * Nitrogen balance * enteral + parenteral intake - urine losses-feces losses- other losses * 6.23 g of pr = 1 g of N * Urine nitrogen losses from 24h urine collection * Index of pr synthesis & breakdown
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88.2.Nutrient Requirements Lipids
* 24-45% of caloric intake * 9 kcal/g of lipid * Digestion * Bile salts⇒emulsification * Pancreatic lipase,cholesterol esterase, phospholipase A2 * Lipolysis stimulated by steroids, catecholamines, glucagon. Inhibited by insulin * Body can synthesize most lipids * linoleic & linolenic LCFA are essential * Minimum of 3% caloric intake as essential FA
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88.3. Nutrient Requirements Nucleotides & Vitamins
* Nucleotides * Fat soluble vitamins : A,D,E,K * Water soluble vitamins : B1, B2, B6, B12, niacin, folate, biotin, pantothenic acid * Trace elements : Fe, Zn, Cu, Cr, Se, Mn, I
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89.Starvation
Effects of fasting * Overnight fast⇒ depletion of liver glycogen * 24h fast⇒depletion of CHO stores * First days⇒degredation of pr & fat * depression of insulin * breakdown of muscle pr * liver gluconeogenesis from aas * TG hydrolysis⇒FFA⇒energy for gluconeogenesis
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89.1.Starvation
* Gluconeogenesis from aas * Urinary nitrogen secretion of 8-12g/day (urea) * Loss of 340g/day of lean tissue * Loss of 35% lean body mass in 1 month ⇒death * However : if sufficient water intake ⇒ starvation can be survived for 2-3 months * adaptation of metabolism to conserve energy by recycling metabolic intermediates
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89.2.Starvation
* Metabolic adaptations to chronic starvation * After 10 days of starvation, brain starts using ketones as 1o fuel * ↓ in basic metabolism * ↓HR * ↓ of voluntary activity * ↑ in blood ketone levels * ↓ in gluconeogenesis * Urinary nitrogen excretion falls to 2-3g/day
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90.Elective Operation or Trauma
* Neurohormonal activation * Epinephrine,cortisol - adrenals * Norepinephrine - sympathetic nerves * ADH- post pituitary * ACTH,TSH,GH - anterior pituitary * Glucagon * Peripheral lipolysis (glucagon,epinephrine,T3) * Accelerated catabolism-proteolysis (cortisol) * ↓peripheral glc uptake (GH,insulin) * glc intolerance * Water & Na urinary excretion * 15-20g/day * lean tissue loss of 750g/day - severe trauma * W/out nutrients the median survival is 15 days
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91.Sepsis & Nutrition
* Inflammatory cytokines * TNFa, IL-1,IL-6 * Marked muscle catabolism * Plasma glc, aas, FFA ↑ * Glc intolerance * Urinary nitrogen excretion 20-30g/day * Without nutrients the median survival is 10 days
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92.Surgical Patient Diet
Surgical pt can't eat : * up to 6h before anesthesia * under sedation * before upper GI endoscopy * after major upper GI procedures * bowel obstruction * paralytic ileus Optimal diet: * CHO 55-60% (230-275g/day) * Fat 30% (70-75g/day) * Protein 10-15% (95-100g/day) * Cholesterol 300 mg/day - 1 egg yolk * Salt 3g/day * Fibers 25g/day * Vitamins * Total calories 2000-2500kcal/day - 30kcal/kg/day
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93.Normal Diet
Benefits: * Most physiological * Metabolic benefits * Production of gut immunoglobulins * Easily accepted by patient * Reduces post-op complications * Safer * Low cost Problems: * Cannot be used for paralytic ileus or bowel obstruction * Risk of vomiting & inhalation * Patient anorexia⇒inadequate caloric intake
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94.Enteral Nutrition
* Food directly into the gut * Blenderized food or special formulas * Can be given with syrienge * a pump controls the mixture administration rate Benefits: * Preferred method of nutritional support for pt unable or unwilling to eat * Preserves gut functionality * Blenderized foot may be given * Lower cost than parenteral nutrition Problems * Cannot be used in pt needing bowel rest * Delivery method requires a tube placement, dietary formulas, monitoring of feeding * Technical problems (5%) - tube clogging or displacement * Metabolic problems (25%) - nausea, vomiting, diarrhea, distension, hypernatremia, hyperglucemia
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95.Parenteral Nutrition
* Nutrients given directly in blood * Requires specialized sterile nutritional slns * Circumvents digestive tube completely ⇒ bowel rest * Route of administration : peripheral parenteral nutrition, total parenteral nutrition Indications * short bowel syndrome \<100cm w/out colon, \<50cm w/ colon * ↑output enteric fistulas (\>500ml/d) * surgical pt w : prolonged paralytic ileus, multiple injuries or severe abdominal trauma * severe intestinal malabsorption syndromes * failure to maintain caloric needs w/ enteral nutrition
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95.1.Parenteral Nutrition
Formulas * 3-in-1 mixtures * Dextrose 20-50% * Aas 10% * Fat emulsion 20% * Electrolytes * vitamins * oligo-elements * Benefits * only method for pt w non functional digestive tube * bowel rest * Problems : * requires sterile conditions, catheter, close monitoring * technical problems : catheter clogging, displacement (embolism risk), infection(sepsis) * metabolic problems : hyper-hypoglucemia, electrolyte disorders, liver steatosis, gut mucosal atrophy
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95.2. Peripheral Parenteral Nutrition
* Given through a peripheral vein catheter * Patients requiring nutritional support \< 14 days * To avoid phlebitis the solution osmolarity \< 1000 mosm/L * Great volumes of slns (\>2.5-3L/day) are needed to fulfill caloric needs
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95.3.Total Parenteral Nutrition
* Given through a central venous catheter (subclavian, internal jugular, femoral) or a peripheral inserted central catheter * More concentrated slns - ↑osmolarity *
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96. Hallmarks of Cancer
* Self-sufficiency in growth signals * Insensitivity to anti-growth signals * Evading programmed cell death * Limitless replicative potential * Sustained angiogenesis * Tissue invasion & metastasis * Deregulated metabolism * Evading the immune system * Genome instability * Inflammation
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97.Diagnosis of Cancer
* Fine needle aspiration biopsy * cytological examination- no architecture * breast lumps, lung nodules, thyroid tumours * Core needle biopsy * sliver of tissue for pathological exam * radiological guidance * Excisional biopsy * removal of entire gross tumors * Sampling of a representative area of a lesion
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98.Tumor Grade
* Tumor grade is a histological determination of the degree of cellular differentiation * ↑tumor grade ⇒ tumor is more biologically agressive * tumor grade factors : nuclear pleomorphism, cellularity, necrosis, cellular invasion, # of mitoses * Tumor grade is important for sarcomas, astrocytomas, Hodgkin & non-Hodgkin lymphomas, prostate cancer
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99.Tumor Stage
* Denotes the extent of disease * Most imprtant prognostic & therapeutic strategy deliminating factor * Staging * Clinical * Pathological * Staging systems * TNM * Stage I-IV
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100.TNM Staging System
* Tumor - T * 1o tumor extension * T1-4 * Lymph Nodes - N * Regional lymph node involvement * N0-3 * Metastases - M * Presence of distant metastases * M0-1
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101.Treatment
* Curative surgery * resection of 1o tumor : R0,1 microscopic residual, R2 gross residual * Lymphadenectomy * Regional control * Sampling - staging * Sentinel lymph node - selective lymphadenopathy * Resection of isolated metastases * Adjuvant & neoadjuvant treatments
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102. Palliation
Control of pain, bleeding, obstruction, malnutrition, infection in unresectable advanced cancer Surgical palliation * malnutrition: vascular access, gastrostomy, jejunostomy * Pain * Oncological emergencies : hemorrhage, obstruction, perforation
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103. Indication for Prophylactic Surgery
Removal of an organ that is at high risk of developing cancer due to a present mutation * ulcerative colitis ⇒ total coloproctectomy * familial adenomatous polyposis coli ⇒ total colectomy * multiple endocrine neoplasia (MEN2a&MEN2b)⇒total thyroidectomy * BRCA1&2 ⇒ bilateral mastectomy
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104.Cytotoxic Chemotherapy
* Curative : for hematologic, anal, testicular cancer * Adjuvant : to improve survival after surgery * Neoadjuvant : to facilitate surgical resection by shrinking 1o tumor, to convert an initially unresectable tumor to a resectable one, to test a tumor sensitivity to chemotherapy * Palliative: to prolong survival &/or improve quality of life * systemic vs regional administration * Alkylating agents, platinum analogues, antimetabolites, antimicrotubule agents, topoisomerase inhibitors, antibiotics
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105. Hormonal Therapy
Blocking effects of hormones that stimulate proliferation * Estrogen & androgen inhibitors * Tamoxifen for estrogen sensitive breast c. * Flutamide for prostate cancer * GRH anologues : leuprolide ⇒ pharma castration for breast & prostate cancer * Aromatase inhibitors : Anastroxol for metastatic breast c in postmenapause woman * Somatostatin anagolues octreotide for neuroendocrine tumors of gut etc
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106.Radiation Therapy
* Locoregional control * Alone or in combination w/ surgery * pre or post operative * Mode of delivery * teletherapyi brachytherapy * Effect of radiation * Electrons or ↑E photons, exposure : roentgens, absorbed dose : gray, ionization ⇒ creation of free radicals
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107.Biologic Therapy
Molecular therapeutics exploit the molecular differences btw normal & cancer cells - targeted * Monoclonal antibodies w/ specificity to tumor antigens * Rituximab : anti CD20- non-hodgkin's * Cancer preventative vaccines * HPV,HBV * Immunostimulants & vaccines * BCG infusion for superficial urinary bladder carcinoma * Experiental biological therapy * oncolytic virus therapy, gene therapy, adoptive T-cell cancer therapy
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108.Prognosis
* Survival & disease free survival * Tumor grade * Tumor stage * Optimized & customized treatment strategy * Response to systemic treatment
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109.Paraneoplastic Syndromes
* Cushing syndrome - ACTH-like * Syndrome of inappropriate ADH-secretion * Hypercalcemia- osteolysis- pthlike * Venous thrombosis * DIC
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110. Tumor Markers
Substances that can be deteted in ↑ than normal amounts in serum or body fluids of pts * Prostate-specific antigen * Carcinoembryonic antigen - colorectal cancer * Alpha Fetopr-hepatocellular carcinoma * Cancer Antigen 15-3,27-29-recurrence of breast c * Chromogranin A-prognosis and monitoring of neuroendocrine tumors
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111.Transplantation Definitions
* Allograft : an organ or tissue transplanted from one individual to another * HLA : human leukocyte antigen, the main trigger to graft rejection * Xenograft : a graft performed btw different species * Orthotopic graft : a graft placed in its normal anatomical site * Heterotopic graft : a graft placed in a site different from that where the organ is normally located
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112.Transplant Immunology
* Allorecognition : IDing of antigen * APCs + Alloantigen +MHC * Bcells & antibodies * Tcells * Other cells : NK cells, monocytes/macrophages
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113.Transplant Rejection
* Hyperacute rejection : antibodies bind to ABO blood group antigens * Acute rejection : T-cells cellular, Bcells hormonal rejection * Chronic rejection : fibrosis of small vessels Diagnosis * Clinical & biochemical impaired organ function * Mild systemic immune symptoms : low grade fever, malaise, lymphocytosis * Biopsy * Immunosuppression masks symptoms
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114.Immunosuppression & Side effects
* Corticosteroids,cancineurein inhibitors * Mammalian target of rapamycin inhibitors * Mycophenolic acid, anti-thymocyte globulin Side effects * Opportunistic infection : Cytomegalovirus, Pneumocytosis jiiroveci * Malignancy : Post transplant lymphoproliferative disorders
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115. Transplant Donors
* Living donors * Relatives or emotionally connected people * Organs : kidney,liver lobe * Minimal risk for donor * Deceased donation : heart- beating, brainstem death, non-heart beating donors after circulatory death 1. Registration as organ donor- agreement of next of kin 2. Confirmation of brainstem death-irreversible structural brain damage 3. Surgery for organ procurement 4. Organ preservation 5. Transplantation to receiver
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116.Heart Transplant
* Indication : end-stage heart disease * Matching donor recipient * ABO compatibility * Size match * Technique : orthotopic heart * Survival 5-year 65%
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117. Lung Transplant
* Indication : end-stage lung disease * Matching donor to recipient * ABO compatibility * Size match * Technique : orthotopic single lung, double lung, heart lung transplantation * Survival : 5 year 40%
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118. Kidney Transplant
* Indication : end stage renal failure * Matching donor to recipient * ABO compatibility * HLA typing * Technique : extraperitoneal placement into iliac fossa * Survival : 5-year survival 84%
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119. Pancrease & Islets of Langerhan Transplantation
* Indication: insulin-dependent diabetes - w/kidney transplantation * Technique * Pancreas transplantation: whole organ implanted intraperitoneally or right iliac fossa * Islet cell transplantation: islet cells isolated & embolized into the donor liver through portal venous catheter
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120. Liver Transplantation
* Indication: end-stage liver disease, hepatocellular carcinoma * Child-Pugh score C⇒ indication * High MELD score - ↑er priority * Technique: * Orthotopic liver transplant * Living donor- lobe-transplant * Survival : 5 year graft survival 60%
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121. Small bowel transplant
* Indication : intestinal failure w/ life threatening TPN complication * Short bowel syndrome \<50cm * High risk of acute rejection- gut immune cells