Question

A 30-year-old male patient came to the emergency room with symptoms of severe weakness and dehydration. The nurse interviewed the patient and the nurse learned that the patient had been vomiting for four days. The patient stated, “I think I ate something bad in the party that I attended.” During the admission assessment, the vital signs of the patients are: temperature = 39 degrees Celsius, pulse rate = 116 bpm, respiratory rate = 18 breaths/min, and BP = 86/54 mm Hg. The patient also has dry mucous membranes and tenting of skin when pinched. The doctor orders to start 0.45% normal saline IV. The doctor also orders laboratory tests for serum electrolyte and an ABG. The results of the laboratory tests and the ABG analysis are the following:

Sodium (Na+) = 150

Potassium (K+) = 5.5

Chloride (Cl¯) = 110

BUN = 42

Creatinine = 0.8

Glucose = 86

pH = 7.32

PaCO2 = 35

HCO3 = 20

PaO2 = 90

O2 Sat = 98%

a. What is your interpretation of this arterial blood gas sample?

b. Explain the high potassium in this patient.

c. Discuss how did the patient develop dehydration.

Answer 1

a. According to the ABG test results the pH is less than normal which is 7.35 to 7.45.
Bicarbonate (HCO3) is also less than normal which is 22-26 mEq/L.
Sodium level is high than normal which is 135-145 mEq/L

Potassium is slightly higher (normal level is 3.6 to 5.2 mmol/l)

Chloride levels are higher than normal which is 96 to 106 mEq/l

BUN is also higher than normal which is 7-20 mg/dL

The patient also have respiratory rate, increased pulse rate and high temperature

These ABG results suggest that the patient has metabolic acidosis.

b. Due to increased respiratory rate in the patient, bicarbonate level has fallen down and ph has become acidic. This resulted in shift of potassium from intracellular to extracellular space which makes renal excretion of potassium difficulty. Dehydration also shift of water from with the cell to extracellular space. This also cause movement of potassium out of cell.
This is the reason for hyperkalemia in patient.
c. The cause of dehydration in patient is vomiting which is a result of electrolyte imbalance