Flashcards in Surgery - Pre and Post Op Care, Electrolytes Deck (56):
How to decrease risk of surgical site infections
Hair removal w/ clippers (not razors)
Warm room temperature (will have more blood flow to skin)
Tight blood flucose control
Common causes of post-op fever and the days of these causes
5Ws = wind, water, walking, wound, wonder drugs
1-2 d = Atelectasis (#1), PNA
3-5 d = UTI
4-6 d = DVT
5-7d = wound infection
> 7d = medications (drug fever)
Most common cause of post-op drug fever
How much isotonic fluid do you give per amount of blood lost?
If lose 500 mL blood, give 500 x 3 = 1500 mL isotonic fluid (NS or LR)
normal urine output
0.5-1 mL/ kg / hr
Most common cause of fever in immediate post op period
2nd most common?
1 - Atelectasis
2 - UTI
Preop characteristics of pts likely to experience postop ischemia after noncardiac surgery
1. JVD - tx w ACEi, Bblockers, digitalis, diuretics
2. MI in last 6 mo (< 6% after 6 mo, 40% within 3 mo)
Mitral regurg / aortic stenosis
> 5 PVC / min
Tortuous or calcified aorta
EF < 35%
Perioperative stroke results...
mortality after post op stroke is high
NOT related to hx of multiple strokes or poststroke TIAs
Transfusions of blood through
- hypotonic solutions
- ringers lactate
Hypotonic (D5W / NS)
- swelling of erythrocytes and lysis
- has Ca and causes clotting in IV line --> PE can happen
How long after cig abstinence do you get improvement in postop respiratory morbidity?
Preop hepatic risk - predictors of mortality
Tx malignant hyperthermia
T > 104
Quickly finish surgery
Hyperventilate w/ 100% O2
+ IV dantrolene
alkalinize urine to prevent myoglobin precipitation
When do you see bacteremia post op?
30-45 mins after
BCx x 3
Start empiric abx
When do you get periop MI?
within 1st 2-3 days post op
Greater mortality than non-surgery induced MI
Tx directed at complications (no tPA)
Pulmonary embolus findings
Tachycardia (1st sign)
1st thing suspect when post op pt gets confused and disoriented?
#1 = Hypoxia ; Can be 2/2 sepsis
Ammonium intoxication (in cirrhotic pts)
AKI FeNa of:
Prerenal < 1
Renal > 2
Postrenal > 2
AKI BUN/Cr of:
What can paralytic ileus be prolonged by?
Tx early post op obstruction
- Occurring within 30 days of open operation
- Management is conservative and most resolve spontaneously
- Will not go in early on b/c collagen deposition is happening to fix the cuts made during surgery and that will be very hard to get through. Go back in about 6 weeks is safe
Risk of wound dehiscence
Dehiscence is fascia is not properly sewn together
Can get evisceration --> skin opens up and all ab contents flow out
Factors assoc w / failure of fistula to heal
Foreign body in wound
Radiation damage to area
Infection or inflammatory bowel disease
Epithelialization of fistulous tract
Distal bowel obstruction
Wound healing process
Inflammation - Proliferation - Remodeling
- rapid influx of neutrophils
- then monocytes to phagocytose debris and bacteria and secrete TNF, TGF, PDGF, FGF
- angiogenesis + collagen formation
- fibroblasts enter @ day 3 to lay down collagen
- type 3 collagen (elastic fibrils) predominates
- replaced by type 1 collagen (rigid)
- collagen deposition and degradation reach steady state at ~ 1yr
- needs to be crosslinked by fibroblasts
- fibroblasts also contract w/ SM elements called myofibroblasts --> can result in contractures
2) Growth factors
- Epithelial growth factor
When do you need perioperative abx?
Epithelialization vs wound contraction
Epithelialization responsible for healing of closed incision (usually w/in 48 hrs after incision)
Wound contraction is primary method of closure in open wounds
- can cause 90% reduction in size of open wound but varies if tight skin adherence is present (eg in leg)
- fibroblasts proliferate becoming myofibroblasts and contract wound
- bacteria colonization does not harm process
Wound healing cytokines
Injury: platelets release --
Macrophages release -
- Plasminogen activator inhibitor
Collagen synthesis initiated and progresses upon stimulation by
- Volume repletion so that vol is corrected fast but tonicity is slower to correct
- use D5 1/2 NS
If due to SIADH, water restriction
Otherwise, use 3% saline or Ringer lactate
IV K @ 10 mEq/h (try not to exceed)
Causes of hyperkalemia
C BIG K
CaCl2 (cell membrane stabilization)
Insulin (insulin and glucose are the fastest - give glucose too to avoid hypoglycemia)
Dialysis is ultimate therapy
What med for hyperkalemia counteracts myocardial effects of K w/o reducing serum K level?
- patho phys
"CATS go numb"- Convulsions, Arrhythmias (QT prolongation), Tetany and numbness/parasthesias in hands, feet, around mouth and lips
The neuromuscular symptoms of hypocalcemia are caused by decreased interaction of calcium with sodium channels.
Since calcium blocks sodium channels and inhibits depolarization of nerve and muscle fibers, diminished calcium lowers the threshold for depolarization
Hyper Ca results in osmotic diuresis making hyper Ca worse
1) rehydrate w/ normal saline
2) furosemide for Ca diuresis if volume overload
3) + bisphosphonates longterm
4) Tx underlying cause
Only need to manage immediately severe hypercalcemia. Mild and moderate is treated only if symptomatic
When see SEVERE hypermagnesemia?
What's the earliest clinical indication of hyperMg?
- Advanced renal failure treated w/ Mg- antacids
- OBs +MgSO4 for preeclampsia
Loss of deep tendon reflexes
- docs give pts MgSO4 until see this
Hypermagnesemia clinical findings
HypoTN (arteriolar relaxing)
Changes in Mental status
Hypomagnesemia clinical findings
Like hypo Ca
BUT get torsades!
K wasting by kidney
functional hypoPTH --> lowers serum Ca
Happens in malnourished pts, pts w/ large GI fluid losses
How to rapidly differentiate hypo Ca vs. hypo Mg
Why do we give D5 1/2 NS + KCl to patients?
How do you calculate how much maintenance fluid to give someone?
Prevent ketosis with glucose!
1/2 Normal saline is hypoosmotic fluid and is maintenance fluid to make it isoosmotic with D5
Calculating maintenance fluid:
1st 10 kg --> give 4 cc/kg/hr
Next 10 kg --> give 2 cc/kg/hr
Remainder of weight --> give 1 cc/kg/hr
Trick for hourly maintenance = 40 + weight (kg)
- CO2 used in laparoscopy b/c better solubility in blood so less risk of gas embolism. Also noncombustible
Risks for pneumoperitoneum:
o CO2 embolus in pulmonary artery
o HypoTN 2/2 compression of IVC
Insulin-dep Diabetic pt pre-op
Check glucose AM of surgery
- better to be slightly increased glucose
If gluc > 250 --> + 2/3 AM dose of NPH + reg insulin
If gluc < 250 --> + 1/2 AM dose
Make sure glucose is below 250 mg/dL preop - delay if not so
mets to bone
Vit A intoxication
SCC of lung (PTrH)
Secretion of parathyroid hormone is controlled chiefly by
serum [Ca2+] through negative feedback.
Calcium-sensing receptors located on parathyroid cells are activated when [Ca2+] is low.
Gq receptors!!!! PIP
kidney stones (#1)
cardiac effects - HTN, LVH, calcification of valves
Tx hypovolemic hypernatremia
Mild: D5W + 1/2 NS
Severe: NS, then switch to 1/2 NS
CEntral pontine myleinolysis consequence of
hyponatremia corrected too fast
Correct hypernatremia too fast...
Tx euvolemic or hypervolemic hypernatremia
IV free water may cause RBC lysis b/c osmotic shock
S/E loop diuretics
Prerenal renal failure
Changes in calcium binding w/ pH
Alkalosis (increase pH) --> more albumin binds calcium, therefore less free calcium
Free calcium is the only active form!
When can you start heparin/dvt ppx on a post op patient without increased risk of bleeding?
48-72 hrs after operation is safe if they are hemodynamically stable
Pt NPO for a while + receiving broad spectrum abx. Starts to bleed from IV site. PT and PTT prolonged. What happened?
Vit K deficiency
No food --> no vit K intake
Abx --> get rid of bacteria --> no make Vit K
PT will usually be more elevated than PTT
Meds causing hyperkalemia
ACE inhibitors, ARBs
INhibit renal tubular Cr secretion (artificial increase in serum Cr)