Internal Medicine

0521779407-C02 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 20:53

352 Chronic Respiratory Acidosis Chronic Respiratory Alkalosis

management

■Treat pulmonary infections aggressively.

■Treat bronchospasm if present.

■Avoid ventilator therapy unless process is rapidly reversible.

specific therapy

■Minimize fluid accumulation with judicious use of diuretics

➣Side effects – hypokalemia, metabolic alkalosis

■Acetazolamide can reduce edema, serum [HCO3−], stimulating ven-

tilation

➣Side effects – hypokalemia, metabolic acidosis

■Oxygen therapy, used judiciously, prolongs survival.

➣Side effects – decreased ventilatory drive, worsening hypercapnia

follow-up

■Stabilize or improve PCO2

complications and prognosis

■Extremely variable, but generally poor

Chronic Respiratory Alkalosis...........................

F. JOHN GENNARI, MD

history & physical

■Increase in ventilation for >2–3 days

■Usually asymptomatic

■With CNS disease, Cheyne-Stokes respiration or, with mid-brain

tumors or injury, metronomic hyperventilation (very regular pat-

tern)

■If symptomatic, symptoms due to underlying illness

■Respiratory rate and/or depth of inspiration increased by definition,

but not usually detected on exam, unless abnormal ventilatory pat-

tern present

tests

Laboratory

■Arterial blood gases are diagnostic – PCO2 <35 mmHg, pH >7.45 (see

below for rule of thumb for [HCO3−])

differential diagnosis

■Conditions to distinguish from Chronic Respiratory Alkalosis