Awake acute blood loss acid-base

Acute blood loss leads to decreased cardiac output, tachycardia, hypotension, and hypovolemic shock. Inadequate organ perfusion and oxygen delivery interfere with aerobic metabolism. Increased anaerobic metabolism leads to production of lactic acid and metabolic acidosis. The body’s buffering capacity is reduced due to loss of bicarbonate and hemoglobin during hemorrhage. The kidneys can begin to compensate for a metabolic acidosis by reabsorbing bicarbonate and secreting hydrogen ions, but this process takes time. In awake patients, the primary mechanism by which a metabolic acidosis can be compensated is by increased minute ventilation. Both peripheral and central chemoreceptors respond to decrease pH by increasing alveolar ventilation.