Alkalosis is excessive blood alkalinity caused by an overabundance of bicarbonate in the blood or a loss of acid from the blood (metabolic alkalosis), or by a low level of carbon dioxide in the blood that results from rapid or deep breathing (respiratory alkalosis).
Respiratory alkalosis
Respiratory alkalosis is characterized by a deficiency of CO2 in the blood (hypocapnia), as indicated by a decrease in PaCO2. PaCO2 is below 35 mm Hg (normal level is 45 mm Hg). This condition is caused by alveolar hyperventilation. Elimination of CO2 by the lungs exceeds the production of CO2 at the cellular level, leading to deficiency of CO2 in the blood. Uncomplicated respiratory alkalosis leads to a decrease in hydrogen ion concentration, which causes elevated blood pH.
CAUSES
Pulmonary causes
• Acute asthma
• Interstitial lung disease
• Pneumonia
• Pulmonary vascular disease
Nonpulmonary causes
• Anxiety
• Aspirin toxicity
• CNS disease (inflammation or tumor)
• Fever
• Hepatic failure
• Metabolic acidosis
• Pregnancy
• Sepsis
Metabolic alkalosis
Metabolic alkalosis is a clinical state marked by decreased amounts of acid or increased
amounts of base bicarbonate. It causes metabolic, respiratory, and renal responses, producing characteristic symptoms—most notably, hypoventilation. This condition always occurs secondary to an underlying cause. With early diagnosis and prompt treatment, the prognosis is good; however, untreated metabolic alkalosis may lead to coma and death.
METABOLIC ALKALOSIS
Key signs and symptoms
• Atrial tachycardia
• Confusion
• Diarrhea
• Hypoventilation
• Twitching
• Vomiting
