Fluid and Electrolytes Flashcards Preview

662 > Fluid and Electrolytes > Flashcards

Flashcards in Fluid and Electrolytes Deck (70):
1

Vascular Access Overview 

  • Required to administer IV fluids and medications
  • Useful in obtaining blood sampling for lab tests
  • Types of access depends on medications that need to be administered and anticipated length of use
    • Central vs. peripheral
  • Vascular acces can be utilized for invasive monitoring in critically ill patients 

 

2

Peripheral catheters

Complications?

 

  • Most commonly used catheter in the acute care setting
  • Usually placed in a vein of the hand or arm, placed distally if possible
  • CDC Guidelines recommend changing of catheter every 96 hours
  • Infection, Phlebitis, Extravasation, Infiltration, Air embolism, Hemorrhage, Hematoma 

3

Peripherally Inserted Central Catheters (PICC)

 

  • Good for patietns who are staying long IV acces
  • Alternative to Subclav lines, internal jugular lines or femoral lines, which have higher rates of infection
  • Insertions requires specialised training
  • Complications
    • Catheter occlusion, phlebitis, hemorrhage, thrombosis, infection

 

4

Central Venous Catheters

  • Allows administrations of large volumes of fluid, blood products, TPN, caustics, vasopressors, chemo
  • Capabe of monitoring hemodynamics CVP
  • Placed into a large vein in the neck (internal jugular vein). chest or groin
  • Complications
    • Pneumothorax, Thrombosis, Infections, Air embolism 

5

Intraosseous

  • Entry into the bone marrow to provide a non-collapsible entry point into the systemic venous system
  •  Any medication that can be administered via IV can be administered via IO
  • Useful in emergency situations when IV access cannot be obtained
  • Requires specialized training
  • EM nurses, EMT
  • Can be utilized for ~24 hours
  • Complicatons 
    • Fat embolism, fracture, osteomyelitis, compartment syndrome, Abscess, skin necrosis

6

Complications of IV therapy

  • Infiltration
    • Non-vesicant fluid leaks into surrounding tissue
  • Infections
    • Punture interrupts skin integrity
  • Phlebitis
    • Inflammation of the vein
  • Thromophlebitis
    • Irritation of vein with clot formation
  • Extravascation 
    • Leakage of vesicant fluid into surrounding tissue 

7

Comparison  fo Options for Vascular Access

A image thumb
8

Total Body Water

1 liter of fluid =?

70 kg male =

  • For clinical purposes, total body fluids = 60% body weight for adults 
  • Percent decreases as body fat increases
  • decreases with Age 
  • For calculations, use hydrated (normal) weight unless patient is obese (>20% of IBW) use IBW
  • 2.2Ibs(1 kg)
  • 42 liters 

9

Intracellular fluid 

  • Water within cells
  • 2/3 of TBW
  • 40% of body weight
  • Rich in electrolytes
    • K, Mg, Phosphates, Proteins

10

Extracellular fluid (ECF) 

 

  • Fluid outside cell
    • Rich in Sodium, Chloride, bicarb
  • 1/3 of TBW
  • Made up of two major fluid sub compartements 
    • Interstitual/ lymph 
      • Fluid space between cells
    • Intravascular 

11

Fluids, Electrolytes, Acid-Base losses

 

  • Sensible
    • Urine, stool
    • Water, sodium, K
  • Insensible
    • Lung, evaporation through skin, fever
    • Mostly water and a little Na+
  • Other
    • Nasogastric tube suction
    • Nasojejunal tubes
    • Drains
    • Fistula tracts
    • Burns 

12

Intravascular Depletion Acute problem

Signs/Symptoms and causes 

A image thumb
13

TBW depletion Chronic problem 

A image thumb
14

Replacement therapy Determining the Needs

  • Ongoing exceptional loss
    • If ongoing problems are not accounted for, a second insufficiency will develop soon after correction of the current deficiency 
    • Replacement regimen should match as closely as possible both the amount and composition of the exceptional losses
    • At minimum, realize that exceptional fluid losses maybe be occuring and be particularly vigilant to monitor these patients for S/S of fluid depletion 

15

Maintenance Basal Requirements 

Neonate (1-10 kg)

Child (10-20)

Adults > 20 

  • 100 ml/kg
  • 1000 ml + 50 ml for each kg > 10 
  • 1500 mL + 20 ml for each kg >20 '
  • For sensible losses in hospitalized pts not taking much PO

 

16

Isotonic fluids 

(310 mEq/L) 

 

fluid doesnt shift from ECF to ICF 

 

 

17

Hypertonic > 376 can help?

Draws water out of cells into ECF

Help stabalize bp, increase urine output, and reduce edema

18

Hypotonic < 250 

Water is pulled from vascular compartments into interstitial fluid is diluted 

19

Crystalloid solutions

  • Electrolyte solutions supply water and sodium to maintain the osmotic gradient between ICF and ECF
  • Plamsa volume- expanding capability of crystalloid is directly related to its sodium concentration
  • D5W: Free water

20

IV fluid comparisons

A image thumb
21

IV fluid comparisons continued 

A image thumb
22

Choice of approptiate fluid?

Define?

Pts with impaired tissue perfusion?

Standard therapy?

  • Define primary type of fluid problem 
    • TBW depletion vs. ECF depletion 
  • ITP- immediate therpeutic goal 
    • Return volume to intravascular space and ECF compartment
    • Standard therapy is to administer normal saline quickly (150-500 mL/hr) until S/S of impaired tissue perfusion have minimized or disappeared 
      • Pt may be switched to a more hypotonic solution 

23

In pts demonstrating impaired tissue perfusion?

  • LR is an alternative, however, lactate may be problematic during massive prolonged infusions 
  • In severe cases, a solution may be indicated that increases in oncotic pressire within the vasculature space
    • Colloid 
    • blood cells (specially indacted if oxygen-carrying capacity of blood is compromised) 

24

In patients with elevated plasma osmolarity and serum sodium concentrations 

  • In patients demonstrating elevated plasma osmolality and serum sodium concentrations
  • Virtually always have a water-deficit problem and, in the absence of S/S of impaired tissue perfusion, primarily need hydration (water) therapy
  •  Hypotonic solutions: more efficient at replenishing the ICF than do isotonic solutions and reduce the plasma osmolality more quickly 
  •  Solution should have a lower sodium concentration than the patient's serum, but do not drop the serum sodium too quickly (CAUTION - cerebral edema)
  • D5½ NS is a commonly-used general rehydration solution; hypertonic or colloidal solutions have no role in treating TBW depletion

25

Monitoring therapy

Parameters?

Therapuetic goal:  resolve S/S of fluid deficit and normalize lab values as much as possible 

  • Physical S/S (thirst, sunken fontanelles, CNS problems)
  • Orthostatic blood pressure 
  • Pulse rate
  • Wt changes
  • Blood chnages
  • Blood chemistries 
  • FLuid input vs. fluid output
  • CVP, PCWP, cardiac output (ICU pts) 

 

26

Monitoring therapy?

Replenish fluids ______ in conditions that may?

Failure?

  • more cautiously in conditions that may predispose a pt to fluid overload
    • Renal failure 
    • Cardiac failure 
    • Hepatic failure 
    • Elderly 

27

Fluid deficiency summary? 

A image thumb
28

Summary - fluid overload 

  • Excess intake
    • Excess IV fluids 
    • Blood/plasma use
    • hypertonic fluids 
    • Excess dietary sodium 
    • Water intoxication 
    • Remobilization of edema
  • Inadequate Output
    • CHF
    • Cirrhosis
    • Nephrotic syndrome 
    • Hyperaldosteronism
    • Low dietart protein
    • Steroid use 

29

Electrolyte distribution 

Total # of anions = ? 

Critical that cell membrane keep? 

___ concentrations reflect total body stores of ECF electrolytes rather than that of ICF electrolytes

  • total number of cations in each fluid compartment 
  • keep the ICF and ECF separate and biochem distinct
  • Serum  

30

Serum electrolyte normal values? 

A image thumb
31

Sodium disorders (___- ____) 

Physiology 

  • 135-145
  • Predominant cation of the ECF
  • Primary electrolyte in establishing osmostic pressure between the ICF and ECF
  • All body fluids are in osmotic equilibrium and changes in serum sodium concentration (Na) are associated with shifts of water in and out of body fluid compartements 
    • Adding Sodium in the intravascular compartment from the interstitial fluid and, ultimately from ICF

32

Sodium disorder

A pts Na concentration should not be used because it doesnt reflect?

Na imbalances cannot be properly assesses without?

Na disorders are ___ disorders?

Normal sodium maintenance is? 

  • Not be used as an index of sodium because it does not reflect total body sodium content, Na primarily reflects disturbances in TBW
  • Without first assessing the body fluid status 
  • Water disorder
  • 80-120 meq/day 

33

Hyponatremia: Signs and Symptoms 

Usually exhibited at < 120 meq/L 

Usually as <110 

  • Agitation 
  • Fatigue
  • HA
  • Muscle cramps 
  • Nausea/anorexia

 

  • Confusion 
  • Seizures
  • Coma 

34

Hypertonic Hyponatremia

Usually associated with _____ 

Treat the ___ as this is corrected the [Na] will?

hyperglycemia 

Treat the hyperglycemia na with return to normal 

35

Diagnostic algorithm for hyponatremia 

A image thumb
36

Diagnostic algorithm for hyponatremia 

continued 

A image thumb
37

Calculation of sodium deficit in a 75 kg male with a serum sodium of 123 mEq/L

Sodium deficit = (45 liters)(140 mEq/L - 123 mEq/L) = 765 mEq

STOPPED at HYPERNATREMIA 

38

Causes of Hypernatremia

First 4 lead to?

5

  1. Dehydration = loss of hypotonic fluid (respiratory, skin losses)
  2. Decreased water intake
  3. Osmotic diuresis
  4. Diabetes insipidus (decreased ADH activity)
    1. May be induced by certain drugs (lithium, phenytoin)
  5. Latrogenic- Admin of too mich hypertonic saline-uncommon

39

Hypernatremia treatment

Calculate TBW deficit?

replace deficit over? with?

  • Water def= Normal TBW - Present TBW
  • Over 48-72 hours with solution hypotonic to pts serum 

40

Hypernatremia treatment

Overly-___ correction may lead to?

The rate at which hypernatremia should be corrected depends on the severity of symptoms and the degree of?

For ____ pts, the rate of correction probably should not exceed?

Rule of thumb?

 

  • Rapid may lead to cerebral edema and death
  • Hypertonicity
  • Asymptomatic, 0.5 mEq/L/hour
  • Replace half the calculated deficit with hypotonic solutions over 12 to 24 hours 

41

Hypernatremia example

Calculate the water deficit in a 75 kg patient male with a serum sodium of 156 mEq/L

Water Def (L) = TBW x [(serum sodium/140)-1]

45 x 0.1 = 5 L

42

Calcium disorders (__-__)

Ca and phos concentrations regulated by?

Normal calcium maintenance requirement 

Corrected calcium accounts for? Calculation?

  • 9-10.5 mg/dL
  • Parathyroid hormone (Increased, increases calcium concentration
  • Vit D
  • Calcitonin increased, decreases calcium 

 

Maintenance- 800-1200

CC- accounts for a decrease in percent of protein binding due to decrease albumin concentration

CC= observed [Ca] + 0.8 (normal albumin*-observerd albumin)

Normal = 4 g/dL

43

Hypocalcemia sign/symptoms and causes

A image thumb
44

Checking Trousseaus Signs?

  • Apply a BP cuff to pts upper arm and inflate
  • Pt will experience adducted thumb, flexed wrist and metacarpophalangeal joints
    • Carpopedal spasm=tetany

45

Checking for Chvosteck signs

  • Tap on pts focial nerve adjacent to the ear
  • Brief contraction of upper lip, nose, or side of face indicated tetany 

46

Calcium supplements

A image thumb
47

IV calcium replacement products which one is preferred and why?

How are they given?

Calcium gluconate- preferred less irritating

Calcium chloride- irritating to veins-->central line

 

Preparation given as slow push or added to 50 mL to 250 mL .9% NaCl, LR, D5W for slow infusion 

48

Indications for IV calcium for Acute Hypocalcium 

  • Pt symptomatic (patesthesia, tetany, Chvostek sign)
  • Clinically relevant hypocalcemia (serum Ca < 1 mmol/L)
  • Massive blood transfusion (especially with preexisting cardiac disease)
  • CCB overdose
  • Receiving inotropic or vasopressor support
  • Emergent hyperkalemia 

49

Hypocalcemia treatment

Acute symptomatic hypocalcemia

  • 200-300 mg of elemental calcium IV and repeat until symptoms fully controlled 
    • 1 gram of calcium chloride or 2-3 grams of calcium gluconate
    • No faster then 30-60 mg of elemental calcium per minute
    • Caution if serum phosphate elevated or if on digoxin therapy 

50

Hypercalcemia treatment

  • Consider if pt symptomatic and/or serum concentration > 12 mg/dL
  • 0.9% NaCl +- furosemide
    • Infusion rate as high as 200-300 ml/hr may be needed
    • Only ass loop diuretic after initial ECF depletion has been corrected
    • Function kidney needed (hemodialysis alternative)
    • Monitor [K] and [Mg] Carefully 

51

Treatment strategies and modalities for Hypercalcemia

A image thumb
52

Suggested treatment regimens for Hypercalcemia

  • Because of polyuria, pt is usually dehydrated
  • Normal saline 200-300 mL/hr, checking for continued dehydration or fluid overload. Goal: up tp 4 L on day one
  • Once rehydrated, add furosemide (Block Ca reabsorption) 40-80 mg IV Q 1-4 hours until urine output = 200-250 mL/hour
  • Monitor serum K and Mg 

53

Phosphorus disorders (___-___)

Express phosphate in mg or mmoles not milliequivalents

# of mmoles = 

Normal maintenance phosphate requirement

  • 3-4.5 mg/dL
  • = amount in mg/ atomic moleculat wt
  • 800-1200 mg/day (250 mg = 8 mmol)

54

Hypophosphatemia treatment

  • Mild 2-2.5
    • Eat
  • Moderate 1-2.5 
    • Oral therapy
      • 1.5-2 grams/day divided into 3-4 doses
      • Diarrhea may be dose limiting
  • Severe <1
    • Parenteral therapy indicated
      • .o8-.64 mmol/kg
      • Range 5-45 over 4-12 hours
      • Select replacement based on need for other electrolytes (Na vs. K)
      • Caution in pts with hypercalcemia, renal dysfunction, or evidence of tissue injury
      • Switch to oral supplement when level 2-2.5 mg/dL

55

Phosphate replacementproducts

A image thumb
56

 IV Phosphate repletion protocol

A image thumb
57

Hyperphosphatemia treatment

  • Dietary restriction of phosphate and protein
  • If tetany (spasms) administer calcium salts IV (see hypocalciemia aboce)
  • Diaylsis of caused by renal failure
  • Oral phosphate binders
    • Mg hydroxide (milk of Mg)
      • Can cause diarrhea
    • Calcium carbonate
      • Inexpensive, tablen can be crushed 

58

5 phosphate binders for treating hyperphosphatemia

  1. Mg hydroxide (milk of Mg)
    1. Can cause diarrhea
  2. Calcium carbonate (tums)
    1. inexpensive, tablets can be crushed
  3. Calcium acetate 
    1. 2 tabs/each meal 
  4. Sevelamer carbonate
    1. Cationic polyer, contains neither Ca ot Al
    2. 800-1600 mg/each meal
  5. Lantanim carbonate
    1. Initial dose 250-500 mg PO 3 x daily to max 3750 mg/day
    2. most need 1500-3000 mg/day 

59

K dissorders (___-___) 

Normal maintenance

3.5-5 mEq/L

0.5-1 mEq/kg/day or 40-50 mEq/day 

60

Causes of hypokalemia

A image thumb
61

Potassium supplements

A image thumb
62

Hypokalemia treatment

Moderate

Severe

  • Moderate hypokalemia (2.5-3.5) without EKG change
    • Usually replace orally at dose of 40-120 mEq/day
  • <2.5 and or EKG change
    • Initiate IV replacement 
      • 1 mEq fall in serum K from 4-3 is a 200 mEq deficit
      • Serum K <3.0
        • Total body deficit increases by 200-400 mEq for each 1 mEq reduction in serum concentration 

63

Recommended K dosage/infusion rate guideline

A image thumb
64

Hyperkalemia causes

  • Increased K intake
    • Excessive intake
    • Blood transfusion
    • Rapid excessive IV admin
  • Decreased K elimination
    • Renal failure
    • Medications (ACEs, Bactrim, spironolactone, NSAIDs)
    • Addisons disease decrease cortisol production
  • K release from cells
    • Tissue breakdown (surgery, trauma, hemolysis, rhabdomyolysis)
    • Metabolic acidosis
  • Pseudo-hyperkalemia
    • Hemolyzed blood samples

65

Treatment of Hyperkalemia

A image thumb
66

Mg disorders (__-__)

Normal maintenance?

1.4-1.8

280-350 mg/day

67

Empiric treatment of Hypomagnesemia

A image thumb
68

Hypomagnesemia treatment

  • Diarrhea may be dose-limiting with oral therapy
  • Replace more cautiously in those with renal dysfunction
  • Hypokalemia must be corrected concomitantly
  • Generally takes 3-5 days to restore levels because up to 50% of a dose is excreted in urine, monitor renal function, adjust replacement if needed

69

Hypermagnesemia treatment

  • IV calsium gluconate- temporarily reverses neuromuscular and cardiavascular effects
    • Indicated if [Mg] > 5.0 mEq/L with symptoms or if >8 without
    • 1-2 grams repeat if needed
  • 0.9% NaCl + furosemide (good renal function) or hemodialysis (renal failure)
  • D/C all Mg containing medications (MOM, Maalox) 

70

Summary

Electrolyte disorders need to be?

Understanding the ___ of electrolyte disturbances is?

Knowledge of appropriate electrolyte strategies based on?

Including?

  • Identified and treated rapidly
  • cause of electrolyte disturbances is important to ensure continued insult is not occurring
  • Based on pts serum electrolyte levels
    • Including rate of adminitration based on IV access