Fig. 4
From: Pathophysiology and clinical consequences of arterial blood gases and pH after cardiac arrest
The pathophysiologic vicious circle after cardiac arrest: hyperventilation and hypocapnia can quickly cause intracellular and extracellular pH increase; this increases metabolic energy and O2 demand, while ATP production is reduced in cardiac arrest for the activation of the anaerobic pathway; this determinates a sympathetic-like activation aimed to compensate the increased energy demand. Also, cardiac arrest per se' and pH derangements strongly influence intracellular function, thus increasing metabolic expenditure, and oxygen consumption. This occurs in the contest of cardiac injury related to the cardiac arrest as well as to pH changes which can further impair cardiac function; impaired myocardium function results in impaired diastolic function with further hyperventilation and hypocapnia. O2, oxygen; ATP, adenosine triphosphate