Principles of Surgical Physiology

Question 1

Total body water comprises slightly less than _/3 of total body weight?

Answer 1

2/3

Question 2

Approx what percent of body weight is plasma volume?

Answer 2

~5%

Question 3

Plasma is what percent of blood volume?

Answer 3

~60%

Question 4

What’s the main intracellular ion?

Answer 4

Potassium (Kin)

Question 5

What’s the main extracellular ion?

Answer 5

Sodium

Question 6

What’s the minimum daily urine excretion in mL/kg/hr?

Answer 6

0.5mL/kg/hr

Question 7

What’s the shortcut for estimating fluid maintenance?

Answer 7

First 20kg = 60mL/hr, then add 1mL/kg/hr above that

Question 8

What two pathological processes can increase water needs?

Answer 8

1. Fever

2. Increased respiratory rate

Question 9

Which maintenance fluid is near perfect?

Answer 9

D5 1/2 NS with 20mEq/L potassium

Question 10

What kind of hyponatremia do the following cause: hyperglycemia, mannitol infusion?

Answer 10

Hyperosmolar hyponatremia

Question 11

What kind of hyponatremia do the following cause: hypertriglyceridemia, hyperlipidemia, hyperproteinemia (large molecules displace water)

Answer 11

Normoosmolar (pseudohyponatremia)

Question 12

What kind of hyponatremia do the following cause: renal losses, RTA, cerebral salt wasting, GI losses, tea and toast syndrome, burns, trauma?

Answer 12

Hypovolemic hypoosmolar hyponatremia

Question 13

What kind of hyponatremia do the following cause: low CO, hypoalbuminemia, renal failure, CHF, nephrotic syndrome (anything where the RAAS system and ADH can’t be excreted by the kidneys)?

Answer 13

Hypervolemic hypoosmolar hyponatremia

Question 14

What kind of hyponatremia do the following cause: SIADH, psychogenic polydipsia, glucocorticoid deficiency, hypothyroidism?

Answer 14

Euvolemic hypoosmolar hyponatremia

Question 15

In which condition should you avoid giving hypertonic solution?

Answer 15

SIADH

Question 16

What’s the tx for respiratory acidosis?

Answer 16

Increase alveolar ventilation (usually with mechanical ventilation)

Question 17

What’s the tx for metabolic acidosis?

Answer 17

Correction of underlying problem and proper fluid/electrolyte management

Question 18

When do you give bicarb for metabolic acidosis?

Answer 18

When pH <7.2 or when loss of bicarb (diarrhea, RTA) is the primary issue

Question 19

What’s the tx for respiratory alkalosis?

Answer 19

Decrease the minute ventilation rate

Question 20

What’s the treatment for metabolic alkalosis?

Answer 20

Stop the loss of chloride and replace water and chloride with isotonic NaCl and K