Internal Medicine

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

Chronic Respiratory Alkalosis Chronic Respiratory Failure 353

➣Metabolic acidosis

➣Mixed disorders

Metabolic acidosis and respiratory alkalosis

Acute on chronic respiratory alkalosis

■Rule of Thumb:

➣Expected [HCO3−] in chronic respiratory alkalosis:

➣[HCO3−](expected)=24 mEq/L−0.4×(40−PCO2, mmHg)

Observed [HCO3−] should be within 4 mEq/L of the expected value

in uncomplicated chronic respiratory alkalosis.

■Causes of Chronic Respiratory Alkalosis

➣Sustained hypoxemia

➣High altitude exposure

➣Pregnancy

➣Hepatic failure

➣Interstitial pulmonary disease

➣CNS disease – cerebrovascular disease, tumors

➣Drugs – progesterone, salicylates

management

■No treatment necessary for alkalosis per se – disorder is sign helping

to diagnose underlying diagnosis (e.g., CNS disease, hepatic failure)

specific therapy

n/a

follow-up

■Dependent on underlying condition

complications and prognosis

■Dependent on underlying condition

■Very poor if secondary to hepatic failure or CNS disease

Chronic Respiratory Failure.............................

THOMAS SHAUGHNESSY, MD

history & physical

Risk Factors

■Malnutrition

■Catabolic nutritional state: Sepsis, burn, ARDS, multiple organ fail-

ure syndrome (MOFS), systemic inflammatory response syndrome

(SIRS)