Lab Studies

Question 1

ABG Normal Values

Answer 1

pH 7.35-7.45

CO2 35-45

HCO3 22-26

PaO2 80-100

BE -2 to 2

SaO2 > 95%

Question 2

Base Excess

Answer 2

Normal -2 to 2
> 4 is an indicator for potential need for blood transfusion
> -19 correlates with a negative outcome

Question 3

Base Excess Replacement Formula

Answer 3

0.1 x (-BE) x patient weight in kg = Bicarb needed (mEq)

Question 4

CO2 Regulation

Answer 4

• diffusion into circulation –> pulmonary capillaries
• Capillary/alveolar membrane –> alevoli
• CO moves blood to tissues
• CO2 regulation is a function of minute volume

Question 5

Anion Gap Equation

Answer 5

(Na+) - (Cl- + HCO3-)

Normal anion gap is 12 +/- 4

Question 6

Metabolic Alkalosis

Answer 6

pH > 7.35 and Bicarb > 26

• Usually result of H+, K+, Na+, Cl- loss
• Causes: vomiting, NG tube suctioning, diuretics, steroids, antacid poisoning
• Treat underlying cause

Question 7

Metabolic Acidosis

Answer 7

pH < 7.35 and Bicarb < 22

• # 1 cause is lactic acidosis
• Ketoacidosis
• Treat underlying cause

Question 8

Respiratory Alkalosis

Answer 8

pH > 7.35 and CO2 < 35

• Result of alveolar hyperventilation
• Often caused by ASA poisoning (stimulates resp. center), or hyperthermia, hypermetabolic states
• Check Vt then f if on a vent

Question 9

Respiratory Acidosis

Answer 9

pH < 7.35 and CO2 > 45

• Result of failure to remove CO2
• Chest wall injury, CNS depression, lung injury

Question 10

Anion Gap Causes

Answer 10

• Methanol
• Uremia
• DKA
• Propylene Glycol
• Isoniazid (INH/Iron
• Lactate
• Ethylene Glycol
• Salicylates

Question 11

Anion Gap Acidosis Treatment

Answer 11

Ventilation/secure airway, find cause, if pH < 7.0 consider bicarb based on severity.

Question 12

BMP Values

Answer 12

Na+ - 135-145 mEq/L
K+ - 3.5-5 mEq/L
Cl- - 95-105 mEq/L
CO2 - 22-26 mEq/L
BUN - 6-24 mg/dL
Cr - 0.7-1.4 mg/dL
Glucose - 80-120 mg/dL

Question 13

CBC Values

Answer 13

HGB/HCT - 15/45
PLT - 150k-450k
WBC - 5k-10k

Question 14

Albumin

Answer 14

Primary serum protein, prodcued by the liver, maintains colloid osmotic pressure.

Question 15

Coag Panel

Answer 15

PT - 11sec (Extrinsic Pathway)
PTT - 21-35sec (Intrinsic Pathway)
INR - 1.0 (International Normalized Ratio)

Question 16

Heparin/LMWH

Answer 16

• Affects the intrinsic pathway
• OD treated with protamine sulfate

Question 17

Coumadin

Answer 17

• Affects the extrinsic pathway, clinically monitored by measuring INR
• Therapeutic INR typically 3-4
• Overdose treated with vitamin K

Question 18

Urine Output

Answer 18

• Infant - 2cc/kg/hr
• Child - 1cc/kg/hr
• Adult - 0.5cc/kg/hr

Question 19

Osmolarity

Answer 19

• Measure of solute concentration
• Normal serum osmolarity 280-295 mOsm/L
• Increases with dehyration
• Decreases with overhydration