While assessing a patient on the oncology unit, the nurse discovers that the patient has been intermittently vomiting all night. The nurse anticipates that the patient may have which acid-base imbalance?


•Metabolic alkalosis occurs with severe vomiting as a result of a loss of hydrochloric acid and acids from extracellular fluids.

•Vomiting is a major side effect of chemotherapeutic drugs. Antiemetics can be given routinely every 4-6 hours or as prophylaxis before chemotherapy is initiated.

Metabolic Acidosis:
•Caused by loss of bicarb or a build up of acids - Lactic acidosis, diarrhea, renal failure, ketones, ammonium intoxication. Not caused by respiration.
•HCO3 decreases, pH decreases
•Compensation - hyperventilation to eliminate CO2

Metabolic Alkalosis
•Acid (H+) lost from emesis, diuretics, retention of HCO3 from medications, hyperaldosteronism
•Increase in HCO3, Increase in pH
•Compensation - Respiratory centers are not stimulated, this leads to hypoventilation and CO2 retention

Respiratory Alkalosis:
•Caused by excessive ventilation
•Decrease in PCO2, increase in pH
•Compensation - Kidneys excrete HCO3

Respiratory Acidosis:
•Respiratory system is the cause, for ex. hypoventilation
•Increase in PCO2, decrease in pH
•Compensation - Kidneys reabsorb Bicarb (HCO3)

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