Fluids and Electrolytes Chapter18 P107-123

Question 1

What are the two major body fluid compartments?

P107

Answer 1

1. Intracellular

2. Extracellular

Question 2

What are the two subcompartments of extracellular fluid?

P107

Answer 2

1. Interstitial fluid (in between cells)

2. Intravascular fluid (plasma)

Question 3

What percentage of body weight is in fluid?

P107 (picture)

Answer 3

60%

Question 4

What percentage of body fluid is intracellular?

P108

Answer 4

66%

Question 5

What percentage of body fluid is extracellular?

P108

Answer 5

33%

Question 6

What is the composition of body fluid?

P108

Answer 6

Fluids = 60% total body weight:
Intracellular = 40% total body weight
Extracellular = 20% total body weight
(Think: 60, 40, 20)

Question 7

How can body fluid distribution by weight be remembered?

P108

Answer 7

“TIE”:
T = Total body fluid = 60% of body weight
I = Intracellular = 40% of body weight
E = Extracellular = 20% of body weight

Question 8

On average, what percentage of body weight does blood
account for in adults?
P108

Answer 8

≈7%

Question 9

How many liters of blood
are in a 70-kg man?
P108

Answer 9

0.07 x 70 = 5 liters

Question 10

What are the fluid requirements every 24 hours for each of the following substances:
1. Water
P108

Answer 10

≈30 to 35 mL/kg

Question 11

What are the fluid requirements every 24 hours for each of the following substances:
2. Potassium
P108

Answer 11

≈1 mEq/kg

Question 12

What are the fluid requirements every 24 hours for each of the following substances:
3. Chloride
P108

Answer 12

≈1.5 mEq/kg

Question 13

What are the fluid requirements every 24 hours for each of the following substances:
4. Sodium
P108

Answer 13

≈1–2 mEq/kg

Question 14

What are the levels and sources of normal daily water loss?

P108

Answer 14

Urine—1200 to 1500 mL (25–30 mL/kg)
Sweat—200 to 400 mL
Respiratory losses—500 to 700 mL
Feces—100 to 200 mL

Question 15

What are the levels and sources of normal daily electrolyte loss?
P108

Answer 15

Sodium and potassium = 100 mEq

Chloride = 150 mEq

Question 16

What are the levels of sodium and chloride in sweat?

P109

Answer 16

≈40 mEq/L

Question 17

What is the major electrolyte in colonic feculent fluid?

P109

Answer 17

Potassium—65 mEq/L

Question 18

What is the physiologic response to hypovolemia?

P109

Answer 18

Sodium/H2O retention via renin → aldosterone, water retention via ADH, vasoconstriction via angiotensin II and
sympathetics, low urine output and tachycardia (early), hypotension (late)

Question 19

THIRD SPACING
What is it?
P109

Answer 19

Fluid accumulation in the interstitium of tissues, as in edema, e.g., loss of fluid into the interstitium and lumen of a paralytic bowel following surgery (think of the intravascular and intracellular spaces as the first two spaces)

Question 20

THIRD SPACING
When does “third-spacing” occur postoperatively?
P109

Answer 20

Third-spaced fluid tends to mobilize back into the intravascular space around POD #3 (Note: Beware of fluid overload once the fluid begins to return to the intravascular
space); switch to hypotonic fluid and decrease IV rate

Question 21

THIRD SPACING
What are the classic signs of third spacing?
P109

Answer 21

Tachycardia

Decreased urine output

Question 22

THIRD SPACING
What is the treatment?
P109

Answer 22

IV hydration with isotonic fluids

Question 23

THIRD SPACING
What are the surgical causes of the following conditions:
Metabolic acidosis
P109

Answer 23

• Loss of bicarbonate: diarrhea, ileus, fistula, high-output ileostomy, carbonic anhydrase inhibitors
• Increase in acids: lactic acidosis (ischemia), ketoacidosis, renal failure, necrotic tissue

Question 24

THIRD SPACING
What are the surgical causes of the following conditions:
Hypochloremic alkalosis
P109

Answer 24

NGT suction, loss of gastric HCl through vomiting/NGT

Question 25

THIRD SPACING What are the surgical causes of the following conditions: Metabolic alkalosis P110

Answer 25

Vomiting, NG suction, diuretics, alkali ingestion, mineralocorticoid excess

Question 26

THIRD SPACING What are the surgical causes of the following conditions: Respiratory acidosis P110

Answer 26

Hypoventilation (e.g., CNS depression), drugs (e.g., morphine), PTX, pleural effusion, parenchymal lung disease, acute airway obstruction

Question 27

THIRD SPACING What are the surgical causes of the following conditions: Respiratory alkalosis P110

Answer 27

Hyperventilation (e.g., anxiety, pain, fever, wrong ventilator settings)

Question 28

THIRD SPACING What is the “classic” acidbase finding with significant vomiting or NGT suctioning? P110

Answer 28

Hypokalemic hypochloremic metabolic alkalosis

Question 29

THIRD SPACING Why hypokalemia with NGT suctioning? P110

Answer 29

Loss in gastric fluid—loss of HCl causes | alkalosis, driving K⁺ into cells

Question 30

THIRD SPACING What is the treatment for hypokalemic hypochloremic metabolic alkalosis? P110

Answer 30

IVF, Cl⁻/K⁺ replacement

Question 31

THIRD SPACING What is paradoxic alkalotic aciduria? P110

Answer 31

Seen in severe hypokalemic, hypovolemic, hypochloremic metabolic alkalosis with paradoxic metabolic alkalosis of serum and acidic urine

Question 32

THIRD SPACING How does paradoxic alkalotic aciduria occur? P110

Answer 32

H⁺ is lost in the urine in exchange for Na⁺ in an attempt to restore volume

Question 33

THIRD SPACING With paradoxic alkalotic aciduria, why is H⁺ preferentially lost? P110

Answer 33

H⁺ is exchanged preferentially into the urine instead of K⁺ because of the low concentration of K⁺

Question 34

THIRD SPACING What can be followed to assess fluid status? P110

Answer 34

Urine output, base deficit, lactic acid, vital signs, weight changes, skin turgor, jugular venous distention (JVD), mucosal membranes, rales (crackles), central venous pressure, PCWP, chest x-ray findings

Question 35

THIRD SPACING With hypovolemia, what changes occur in vital signs? P110

Answer 35

Tachycardia, tachypnea, initial rise in diastolic blood pressure because of clamping down (peripheral vasoconstriction) with subsequent decrease in both systolic and diastolic blood pressures

Question 36

THIRD SPACING What are the insensible fluid losses? P111

Answer 36

Loss of fluid not measured: a) Feces—100 to 200 mL/24 hours b) Breathing—500 to 700 mL/24 hours (Note: increases with fever and tachypnea) c) Skin—≈300 mL/24 hours, increased with fever; thus, insensible fluid loss is not directly measured

Question 37

THIRD SPACING What are the quantities of daily secretions: Bile P111

Answer 37

≈1000 mL/24 hours

Question 38

THIRD SPACING What are the quantities of daily secretions: Gastric P111

Answer 38

≈2000 mL/ 24 hours

Question 39

THIRD SPACING What are the quantities of daily secretions: Pancreatic P111

Answer 39

≈600 mL/ 24 hours

Question 40

THIRD SPACING What are the quantities of daily secretions: Small intestine P111

Answer 40

≈3000 mL/day

Question 41

THIRD SPACING What are the quantities of daily secretions: Saliva P111

Answer 41

≈1500 mL/24 hours | Note: almost all secretions are reabsorbed

Question 42

THIRD SPACING How can the estimated levels of daily secretions from bile, gastric, and small-bowel sources be remembered? P111

Answer 42

Alphabetically and numerically: BGS and 123 or B1, G2, S3, because Bile, Gastric, and Small bowel produce roughly 1 L, 2 L, and 3 L, respectively!

Question 43

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) What comprises normal saline (NS)? P111

Answer 43

154 mEq of Cl⁻ | 154 mEq of Na⁺

Question 44

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) What comprises 1/2 NS? P111

Answer 44

77 mEq of Cl⁻ | 77 mEq of Na⁺

Question 45

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) What comprises 1/4 NS? P111

Answer 45

39 mEq of Cl⁻ | 39 mEq of Na⁺

Question 46

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) What comprises lactated Ringer’s (LR)? P111

Answer 46

``` 130 mEq Na⁺ 109 mEq Cl⁻ 28 mEq lactate 4 mEq K⁺ 3 mEq Ca⁺ ```

Question 47

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) What comprises D5W? P111

Answer 47

5% dextrose (50 g) in H(2)O

Question 48

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) What accounts for tonicity? P112

Answer 48

Mainly electrolytes; thus, NS and LR are both isotonic, whereas 1/2 NS is hypotonic to serum

Question 49

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) What happens to the lactate in LR in the body? P112

Answer 49

Converted into bicarbonate; thus, LR cannot be used as a maintenance fluid because patients would become alkalotic

Question 50

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) IVF replacement by anatomic site: Gastric (NGT) P112

Answer 50

D5 1/2 NS + 20 KCl

Question 51

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) IVF replacement by anatomic site: Biliary P112

Answer 51

LR+/-sodium bicarbonate

Question 52

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) IVF replacement by anatomic site: Pancreatic P112

Answer 52

LR+/-sodium bicarbonate

Question 53

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) IVF replacement by anatomic site: Small bowel (ileostomy) P112

Answer 53

LR

Question 54

COMMON IV REPLACEMENT FLUIDS (ALL VALUES ARE PER LITER) IVF replacement by anatomic site: Colonic (diarrhea) P112

Answer 54

LR+/-sodium bicarbonate

Question 55

CALCULATION OF MAINTENANCE FLUIDS What is the 100/50/20 rule? P112

Answer 55

Maintenance IV fluids for a 24-hour period: 100 mL/kg for the first 10 kg 50 mL/kg for the next 10 kg 20 mL/kg for every kg over 20 (divide by 24 for hourly rate)

Question 56

CALCULATION OF MAINTENANCE FLUIDS What is the 4/2/1 rule? P112

Answer 56

Maintenance IV fluids for hourly rate: 4 mL/kg for the first 10 kg 2 mL/kg for the next 10 kg 1 mL/kg for every kg over 20

Question 57

CALCULATION OF MAINTENANCE FLUIDS What is the maintenance for a 70-kg man? P112

Answer 57

``` Using 100/50/20: 100 x 10 kg = 1000 50 x 10 kg = 500 20 x 50 kg = 1000 Total = 2500 Divided by 24 hours = 104 mL/hr maintenance rate ``` ``` Using 4/2/1: 4 x 10 kg = 40 2 x 10 kg = 20 1 x 50 kg = 50 Total = 110 mL/hr maintenance rate ```

Question 58

CALCULATION OF MAINTENANCE FLUIDS What is the common adult maintenance fluid? P113

Answer 58

D5 1/2 NS with 20 mEq KCl/L

Question 59

CALCULATION OF MAINTENANCE FLUIDS What is the common pediatric maintenance fluid? P113

Answer 59

D5 1/4 NS with 20 mEq KCl/L (use 1/4 NS because of the decreased ability of children to concentrate urine)

Question 60

CALCULATION OF MAINTENANCE FLUIDS Why should sugar (dextrose) be added to maintenance fluid? P113

Answer 60

To inhibit muscle breakdown

Question 61

CALCULATION OF MAINTENANCE FLUIDS What is the best way to assess fluid status? P113

Answer 61

Urine output (unless the patient has cardiac or renal dysfunction, in which case central venous pressure or wedge pressure is often used)

Question 62

CALCULATION OF MAINTENANCE FLUIDS What is the minimal urine output for an adult on maintenance IV? P113

Answer 62

30 mL/hr (0.5 cc/kg/hr)

Question 63

CALCULATION OF MAINTENANCE FLUIDS What is the minimal urine output for an adult trauma patient? P113

Answer 63

50 mL/hr

Question 64

CALCULATION OF MAINTENANCE FLUIDS How many mL are in 12 oz (beer can)? P113

Answer 64

356 mL

Question 65

CALCULATION OF MAINTENANCE FLUIDS How many mL are in 1 oz? P113

Answer 65

30 mL

Question 66

CALCULATION OF MAINTENANCE FLUIDS How many mL are in 1 tsp? P113

Answer 66

5 mL

Question 67

CALCULATION OF MAINTENANCE FLUIDS What are common isotonic fluids? P113

Answer 67

NS, LR

Question 68

CALCULATION OF MAINTENANCE FLUIDS What is a bolus? P113

Answer 68

Volume of fluid given IV rapidly (e.g., 1 L over 1 hour); used for increasing intravascular volume, and isotonic fluids should be used (i.e., NS or LR)

Question 69

CALCULATION OF MAINTENANCE FLUIDS Why not combine bolus fluids with dextrose? P113

Answer 69

Hyperglycemia may result

Question 70

CALCULATION OF MAINTENANCE FLUIDS What is the possible consequence of hyperglycemia in the patient with hypovolemia? P114

Answer 70

Osmotic diuresis

Question 71

CALCULATION OF MAINTENANCE FLUIDS Why not combine bolus fluids with a significant amount of potassium? P114

Answer 71

Hyperkalemia may result (the potassium in LR is very low: 4 mEq/L)

Question 72

CALCULATION OF MAINTENANCE FLUIDS Why should isotonic fluids be given for resuscitation (i.e., to restore intravascular volume)? P114

Answer 72

If hypotonic fluid is given, the tonicity of the intravascular space will be decreased and H(2)O will freely diffuse into the interstitial and intracellular spaces; thus, use isotonic fluids to expand the intravascular space

Question 73

CALCULATION OF MAINTENANCE FLUIDS What portion of 1 L NS will stay in the intravascular space after a laparotomy? P114

Answer 73

In 5 hours, only ≈200 cc (or 20%) will remain in the intravascular space!

Question 74

CALCULATION OF MAINTENANCE FLUIDS What is the most common trauma resuscitation fluid? P114

Answer 74

LR

Question 75

CALCULATION OF MAINTENANCE FLUIDS What is the most common postoperative IV fluid after a laparotomy? P114

Answer 75

LR or D5LR for 24 to 36 hours, followed by maintenance fluid

Question 76

CALCULATION OF MAINTENANCE FLUIDS After a laparotomy, when should a patient’s fluid be “mobilized”? P114

Answer 76

Classically, POD #3; the patient begins to “mobilize” the third-space fluid back into the intravascular space

Question 77

CALCULATION OF MAINTENANCE FLUIDS What IVF is used to replace duodenal or pancreatic fluid loss? P114

Answer 77

LR (bicarbonate loss)

Question 78

ELECTROLYTE IMBALANCES What is a common cause of electrolyte abnormalities? P114

Answer 78

Lab error!

Question 79

ELECTROLYTE IMBALANCES What is a major extracellular cation? P114

Answer 79

Na⁺

Question 80

ELECTROLYTE IMBALANCES What is a major intracellular cation? P114

Answer 80

K⁺

Question 81

HYPERKALEMIA What is the normal range for potassium level? P115

Answer 81

3.5–5.0 mEq/L

Question 82

HYPERKALEMIA What are the surgical causes of hyperkalemia? P115

Answer 82

Iatrogenic overdose, blood transfusion, renal failure, diuretics, acidosis, tissue destruction (injury/hemolysis)

Question 83

HYPERKALEMIA What are the signs/ symptoms? P115

Answer 83

Decreased deep tendon reflex (DTR) or areflexia, weakness, paraesthesia, paralysis, respiratory failure

Question 84

HYPERKALEMIA What are the ECG findings? P115

Answer 84

Peaked T waves, depressed ST segment, prolonged PR, wide QRS, bradycardia, ventricular fibrillation

Question 85

HYPERKALEMIA What are the critical values? P115

Answer 85

K⁺ >6.5

Question 86

HYPERKALEMIA What is the urgent treatment? P115

Answer 86

- IV calcium (cardioprotective), ECG monitoring - Sodium bicarbonate IV (alkalosis drives K⁺ intracellularly) - Glucose and insulin - Albuterol - Sodium polystyrene sulfonate (Kayexalate) and furosemide (Lasix) - Dialysis

Question 87

HYPERKALEMIA What is the nonacute treatment? P115

Answer 87

Furosemide (Lasix), sodium polystyrene sulfonate (Kayexalate)

Question 88

HYPERKALEMIA What is the acronym for the treatment of acute symptomatic hyperkalemia? P115

Answer 88

“CB DIAL K”: Calcium Bicarbonate Dialysis Insulin/dextrose Albuterol Lasix Kayexalate

Question 89

HYPERKALEMIA What is “pseudohyperkalemia”? P115

Answer 89

Spurious hyperkalemia as a result of falsely elevated K⁺ in sample from sample hemolysis

Question 90

HYPERKALEMIA What acid-base change lowers the serum potassium? P116

Answer 90

Alkalosis (thus, give bicarbonate for hyperkalemia)

Question 91

HYPERKALEMIA What nebulizer treatment can help lower K⁺ level? P116

Answer 91

Albuterol

Question 92

HYPOKALEMIA What are the surgical causes? P116

Answer 92

Diuretics, certain antibiotics, steroids, alkalosis, diarrhea, intestinal fistulae, NG aspiration, vomiting, insulin, insufficient supplementation, amphotericin

Question 93

HYPOKALEMIA What are the signs/symptoms? P116

Answer 93

Weakness, tetany, nausea, vomiting, ileus, paraesthesia

Question 94

HYPOKALEMIA What are the ECG findings? P116

Answer 94

Flattening of T waves, U waves, ST segment depression, PAC, PVC, atrial fibrillation

Question 95

HYPOKALEMIA What is a U wave? P116 (picture)

Answer 95

(see picture)

Question 96

HYPOKALEMIA What is the rapid treatment? P116

Answer 96

KCl IV

Question 97

HYPOKALEMIA What is the maximum amount that can be given through a peripheral IV? P116

Answer 97

10 mEq/hour

Question 98

HYPOKALEMIA What is the maximum amount that can be given through a central line? P116

Answer 98

20 mEq/hour

Question 99

HYPOKALEMIA What is the chronic treatment? P116

Answer 99

KCl PO

Question 100

HYPOKALEMIA What is the most common electrolyte-mediated ileus in the surgical patient? P116

Answer 100

Hypokalemia

Question 101

HYPOKALEMIA What electrolyte condition exacerbates digitalis toxicity? P117

Answer 101

Hypokalemia

Question 102

HYPOKALEMIA What electrolyte deficiency can actually cause hypokalemia? P117

Answer 102

Low magnesium

Question 103

HYPOKALEMIA What electrolyte must you replace first before replacing K⁺? P117

Answer 103

Magnesium

Question 104

HYPOKALEMIA Why does hypomagnesemia make replacement of K⁺ with hypokalemia nearly impossible? P117

Answer 104

Hypomagnesemia inhibits K⁺ reabsorption from the renal tubules

Question 105

HYPERNATREMIA What is the normal range for sodium level? P117

Answer 105

135–145 mEq/L

Question 106

HYPERNATREMIA What are the surgical causes? P117

Answer 106

Inadequate hydration, diabetes insipidus, diuresis, vomiting, diarrhea, diaphoresis, tachypnea, iatrogenic (e.g., TPN)

Question 107

HYPERNATREMIA What are the signs/ symptoms? P117

Answer 107

Seizures, confusion, stupor, pulmonary or peripheral edema, tremors, respiratory paralysis

Question 108

HYPERNATREMIA What is the usual treatment supplementation slowly over days? P117

Answer 108

D5W, 1/4 NS, or 1/2 NS

Question 109

HYPERNATREMIA How fast should you lower the sodium level in hypernatremia? P117

Answer 109

Guideline is

Question 110

HYPERNATREMIA What is the major complication of lowering the sodium level too fast? P117

Answer 110

Seizures (not central pontine myelinolysis)

Question 111

HYPONATREMIA What are the surgical causes of the following types: Hypovolemic P117

Answer 111

Diuretic excess, hypoaldosteronism, vomiting, NG suction, burns, pancreatitis, diaphoresis

Question 112

HYPONATREMIA What are the surgical causes of the following types: Euvolemic P118

Answer 112

SIADH, CNS abnormalities, drugs

Question 113

HYPONATREMIA What are the surgical causes of the following types: Hypervolemic P118

Answer 113

Renal failure, CHF, liver failure (cirrhosis), iatrogenic fluid overload (dilutional)

Question 114

HYPONATREMIA What are the signs/ symptoms? P118

Answer 114

Seizures, coma, nausea, vomiting, ileus, lethargy, confusion, weakness

Question 115

HYPONATREMIA What is the treatment of the following types: Hypovolemic P118

Answer 115

NS IV, correct underlying cause

Question 116

HYPONATREMIA What is the treatment of the following types: Euvolemic P118

Answer 116

SIADH: furosemide and NS acutely, fluid restriction

Question 117

HYPONATREMIA What is the treatment of the following types: Hypervolemic P118

Answer 117

Dilutional: fluid restriction and diuretics

Question 118

HYPONATREMIA How fast should you increase the sodium level in hyponatremia? P118

Answer 118

Guideline is

Question 119

HYPONATREMIA What may occur if you correct hyponatremia too quickly? P118

Answer 119

Central pontine myelinolysis!

Question 120

HYPONATREMIA What are the signs of central pontine myelinolysis? P118

Answer 120

1. Confusion 2. Spastic quadriplegia 3. Horizontal gaze paralysis

Question 121

HYPONATREMIA What is the most common cause of mild postoperative hyponatremia? P118

Answer 121

Fluid overload

Question 122

HYPONATREMIA How can the sodium level in SIADH be remembered? P118

Answer 122

``` SIADH = Sodium Is Always Down Here = Hyponatremia ```

Question 123

“PSEUDOHYPONATREMIA” What is it? P118

Answer 123

Spurious lab value of hyponatremia as a result of hyperglycemia, hyperlipidemia, or hyperproteinemia

Question 124

HYPERCALCEMIA What are the causes? P119

Answer 124

“CHIMPANZEES”: Calcium supplementation IV Hyperparathyroidism (1° /3° ) hyperthyroidism Immobility/Iatrogenic (thiazide diuretics) Mets/Milk alkali syndrome Paget’s disease (bone) Addison’s disease/Acromegaly Neoplasm (colon, lung, breast, prostate, multiple myeloma) Zollinger-Ellison syndrome (as part of MEN I) Excessive vitamin D Excessive vitamin A Sarcoid

Question 125

HYPERCALCEMIA What are the signs/ symptoms? P119

Answer 125

Hypercalcemia—“Stones, bones, abdominal groans, and psychiatric overtones” Polydipsia, polyuria, constipation

Question 126

HYPERCALCEMIA What are the ECG findings? P119

Answer 126

Short QT interval, prolonged PR interval

Question 127

HYPERCALCEMIA What is the acute treatment of hypercalcemic crisis? P119

Answer 127

Volume expansion with NS, diuresis with furosemide (not thiazides)

Question 128

HYPERCALCEMIA What are other options for lowering Ca⁺ level? P119

Answer 128

Steroids, calcitonin, bisphosphonates (pamidronate, etc.), mithramycin, dialysis (last resort)

Question 129

HYPOCALCEMIA How can the calcium level be determined with hypoalbuminemia? P119

Answer 129

(4-measured albumin level) x 0.8, then add this value to the measured calcium level

Question 130

HYPOCALCEMIA What are the surgical causes? P119

Answer 130

Short bowel syndrome, intestinal bypass, vitamin D deficiency, sepsis, acute pancreatitis, osteoblastic metastasis, aminoglycosides, diuretics, renal failure, hypomagnesemia, rhabdomyolysis

Question 131

HYPOCALCEMIA What is Chvostek’s sign? P119

Answer 131

``` Facial muscle spasm with tapping of facial nerve (Think: CHvostek = CHeek) ```

Question 132

HYPOCALCEMIA What is Trousseau’s sign? P120

Answer 132

Carpal spasm after occluding blood flow in forearm with blood pressure cuff

Question 133

HYPOCALCEMIA What are the signs/symptoms? P120

Answer 133

Chvostek’s and Trousseau’s signs, perioral paraesthesia (early), increased deep tendon reflexes (late), confusion, abdominal cramps, laryngospasm, stridor, seizures, tetany, psychiatric abnormalities (e.g., paranoia, depression, hallucinations)

Question 134

HYPOCALCEMIA What are the ECG findings? P120

Answer 134

Prolonged QT and ST interval (peaked T waves are also possible, as in hyperkalemia)

Question 135

HYPOCALCEMIA What is the acute treatment? P120

Answer 135

Calcium gluconate IV

Question 136

HYPOCALCEMIA What is the chronic treatment? P120

Answer 136

Calcium PO, vitamin D

Question 137

HYPOCALCEMIA What is the possible complication of infused calcium if the IV infiltrates? P120

Answer 137

Tissue necrosis; never administer peripherally unless absolutely necessary (calcium gluconate is less toxic than calcium chloride during an infiltration)

Question 138

HYPOCALCEMIA What is the best way to check the calcium level in the ICU? P120

Answer 138

Check ionized calcium

Question 139

HYPERMAGNESEMIA What is the normal range for magnesium level? P120

Answer 139

1.5–2.5 mEq/L

Question 140

HYPERMAGNESEMIA What is the surgical cause? P120

Answer 140

TPN, renal failure, IV over supplementation

Question 141

HYPERMAGNESEMIA What are the signs/ symptoms? P120

Answer 141

Respiratory failure, CNS depression, decreased deep tendon reflexes

Question 142

HYPERMAGNESEMIA What is the treatment? P120

Answer 142

Calcium gluconate IV, insulin plus glucose, dialysis (similar to treatment of hyperkalemia), furosemide (Lasix)

Question 143

HYPOMAGNESEMIA What are the surgical causes? P120

Answer 143

TPN, hypocalcemia, gastric suctioning, aminoglycosides, renal failure, diarrhea, vomiting

Question 144

HYPOMAGNESEMIA What are the signs/symptoms? P121

Answer 144

Increased deep tendon reflexes, tetany, asterixis, tremor, Chvostek’s sign, ventricular ectopy, vertigo, tachycardia, dysrhythmias

Question 145

HYPOMAGNESEMIA What is the acute treatment? P121

Answer 145

MgSO4 IV

Question 146

HYPOMAGNESEMIA What is the chronic treatment? P121

Answer 146

Magnesium oxide PO (side effect: diarrhea)

Question 147

HYPOMAGNESEMIA Hypomagnesemia may make it impossible to correct what other electrolyte abnormality? P121

Answer 147

Hypokalemia (always fix hypomagnesemia with hypokalemia)

Question 148

HYPERGLYCEMIA What are the surgical causes? P121

Answer 148

Diabetes (poor control), infection, stress, TPN, drugs, lab error, drawing over IV site, somatostatinoma, glucagonoma

Question 149

HYPERGLYCEMIA What are the signs/symptoms? P121

Answer 149

Polyuria, hypovolemia, confusion/coma, polydipsia, ileus, DKA (Kussmaul breathing), abdominal pain, hyporeflexia

Question 150

HYPERGLYCEMIA What is the treatment? P121

Answer 150

Insulin

Question 151

HYPERGLYCEMIA What is the Weiss protocol? P121

Answer 151

Sliding scale insulin

Question 152

HYPERGLYCEMIA What is the goal glucose level in the ICU? P121

Answer 152

80–110 mg/dL

Question 153

HYPOGLYCEMIA What are the surgical causes? P121

Answer 153

Excess insulin, decreased caloric intake, insulinoma, drugs, liver failure, adrenal insufficiency, gastrojejunostomy

Question 154

HYPOGLYCEMIA What are the signs/ symptoms? P121

Answer 154

Sympathetic response (diaphoresis, tachycardia, palpitations), confusion, coma, headache, diplopia, neurologic deficits, seizures

Question 155

HYPOGLYCEMIA What is the treatment? P121

Answer 155

Glucose (IV or PO)

Question 156

HYPOPHOSPHATEMIA What is the normal range for phosphorus level? P122

Answer 156

2.5–4.5 mg/dL

Question 157

HYPOPHOSPHATEMIA What are the signs/symptoms? P122

Answer 157

Weakness, cardiomyopathy, neurologic dysfunction (e.g., ataxia), rhabdomyolysis, hemolysis, poor pressor response

Question 158

HYPOPHOSPHATEMIA What is a complication of severe hypophosphatemia? P122

Answer 158

Respiratory failure

Question 159

HYPOPHOSPHATEMIA What are the causes? P122

Answer 159

GI losses, inadequate supplementation, medications, sepsis, alcohol abuse, renal loss

Question 160

HYPOPHOSPHATEMIA What is the critical value? P122

Answer 160

1.0 mg/dL

Question 161

HYPOPHOSPHATEMIA What is the treatment? P122

Answer 161

Supplement with sodium phosphate or potassium phosphate IV (depending on potassium level)

Question 162

HYPERPHOSPHATEMIA What are the signs/symptoms? P122

Answer 162

Calcification (ectopic), heart block

Question 163

HYPERPHOSPHATEMIA What are the causes? P122

Answer 163

Renal failure, sepsis, chemotherapy, | hyperthyroidism

Question 164

HYPERPHOSPHATEMIA What is the treatment? P122

Answer 164

Aluminum hydroxide (binds phosphate)

Question 165

MISCELLANEOUS This ECG pattern is consistent with which electrolyte abnormality? P122 (picture)

Answer 165

Hyperkalemia: peaked T waves

Question 166

MISCELLANEOUS If hyperkalemia is left untreated, what can occur? P123 (picture)

Answer 166

Ventricular tachycardia/fibrillation → death

Question 167

MISCELLANEOUS Which electrolyte is an inotrope? P123

Answer 167

Calcium

Question 168

MISCELLANEOUS What are the major cardiac electrolytes? P123

Answer 168

Potassium (dysrhythmias), magnesium | dysrhythmias), calcium (dysrhythmias/inotrope

Question 169

MISCELLANEOUS Which electrolyte must be monitored closely in patients on digitalis? P123

Answer 169

Potassium

Question 170

MISCELLANEOUS What is the most common cause of electrolyte-mediated ileus? P123

Answer 170

Hypokalemia

Question 171

MISCELLANEOUS What is a colloid fluid? P123

Answer 171

Protein-containing fluid (albumin)

Question 172

MISCELLANEOUS What is the rationale for using an albuminfurosemide “sandwich”? P123

Answer 172

Albumin will pull interstitial fluid into the intravascular space and the furosemide will then help excrete the fluid as urine

Question 173

MISCELLANEOUS An elderly patient goes into CHF (congestive heart failure) on POD #3 after a laparotomy. What is going on? P123

Answer 173

Mobilization of the “third-space” fluid into the intravascular space, resulting in fluid overload and resultant CHF (but also must rule out MI)

Question 174

MISCELLANEOUS What fluid is used to replace NGT (gastric) aspirate? P123

Answer 174

D5 1/2 NS with 20 KCl

Question 175

MISCELLANEOUS What electrolyte is associated with succinycholine? P123

Answer 175

Hyperkalemia