a. Increase in base or bicarbonate (HCO3
–) concentration, generally
reflecting a relative loss or shift of hydrogen (H+)
and/or gain in HCO3
b. Organ systems most often involved are the kidneys and the
gastrointestinal (GI) tract.
c. Consequences of the condition on organ systems dependent
on degree of alkalemia and underlying pathology.
a. Chloride-responsive: Urine chloride is less than 20 mEq/L
and decreased extracellular fluid (ECF) volume.
i. GI acid losses: vomiting, nasogastric suction, diarrhea
associated with villous adenoma
ii. Diuretics: Thiazides and loop diuretics interfere with
reabsorption of sodium and chloride in the renal tubules,
causing loss of chloride.
– excess: correction of respiratory acidosis, chronic
ingestion of large doses of antacids
iv. Laxative abuse
b. Chloride-resistant: Urine chloride is greater than 20 mEq/L
and increased ECF volume.
i. Renal acid loss: primary or secondary hyperaldosteronism,
thiazides or loop diuretics, hypokalemia and
hypomagnesemia; genetic deficiency of 11-B-HSD2 or
inhibition by licorice, chewing tobacco
ii. Renal artery stenosis
c. Other causes
i. Carbohydrate feeding after starvation
iii. Multiple blood transfusions
d. Compensatory mechanisms
i. Rapid excretion of HCO3
– by the kidneys whenever
plasma level exceeds 24 mmol/L—requires normal
kidney function, with the ability to filter HCO3
– and to
excrete excess H+
ii. Hypoventilation: slow, shallow respirations to increase
retention of carbonic acid
a. Morbidity: Primarily related to the underlying disease;
therefore, separate statistics are not collected; most
common acid-base imbalance in hospitalized adults
(Huang & Priestley, 2007).
b. Mortality: 45% for arterial pH over 7.55; 80% for arterial
pH over 7.65 (Yaseen & Thomas, 2007).
This condition does not occur in isolation but rather is a
complication of a broader problem that may require inpatient
care in a medical-surgical or subacute unit.
Plans of care are specific to predisposing factors.
Fluid and electrolyte imbalances,
Renal dialysis—general considerations,
Respiratory acidosis (primary carbonic acid excess),
Respiratory alkalosis (primary carbonic acid deficit),
1. Achieve homeostasis.
2. Prevent or minimize complications.
3. Provide information about condition, prognosis, and
treatment needs, as appropriate.
1. Physiological balance restored.
2. Free of complications.
3. Condition, prognosis, and treatment needs understood.
4. Plan in place to meet needs after discharge.