a. Reflects a relative excess of acid or hydrogen (H+) and a
deficit of base or bicarbonate (HCO3
b. Gain of strong acid may be endogenous (for example,
ketoacids from lipid metabolism) or exogenous (for
example, NH4Cl infusion).
c. Bicarbonate loss may occur via the bowel or kidneys.
II. Etiology—characterized by normal or high anion gap
situations (Priestley, 2007; Thomas & Hamwai, 2007)
a. Normal anion gap (or nonanion gap) acidosis is associated
with loss of bicarbonate from the body, gain of chloride, or
decreased ammonia production.
i. Gastrointestinal (GI) losses: vomiting, diarrhea, smallbowel
and pancreatic or biliary fistulas, ileal loop bladder
ii. Early renal failure
iii. Obstructed ileostomy
iv. Infusion of ammonium chloride, hyperalimentation;
intravenous (IV) sodium chloride in presence of
preexisting kidney dysfunction; acidifying drugs
b. High anion gap acidosis reflects accumulation of organic
i. Diabetic ketoacidosis
ii. Severe malnutrition or starvation, high-fat,
low-carbohydrate diets; parenteral lipid administration
iii. Alcoholic lactic acidosis
iv. Renal tubular necrosis
v. Poisoning: salicylate intoxication (after initial stage),
paraldehyde intoxication; drug therapy including acetazolamide
(Diamox), isoniazid (INH); or NH4Cl
c. Compensatory mechanisms
i. Hyperventilation to reduce PaCO2
ii. Decreased renal secretion of H+, less production of
ammonia, and excretion of HCO3
iii. Treatment of underlying condition
III. Statistics: Morbidity and mortality are primarily related to
the underlying disease; therefore, separate statistics are not
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.