Development of tissue hypoxia during progressive hyperthermia in dogs

¹ Department of Physiology and Biochemistry, Rutgers-The State University, New Brunswick, New Jersey, and Physiology Branch, School of Aerospace Medicine, Brooks Air Force Base, Texas

Heart rate, mean arterial pressure, respiratory rate, minute volume, arterial blood, Po₂, Pco₂, pH, hemoglobin saturation, lactic acid, and pyruvic acid were determined on anesthetized dogs during progressive hyperthermia. Heart rate increased as rectal temperature (T_r) increased. Mean arterial pressure began to decline at T_r between 41 and 42 C. Respiratory rate and minute volume reached maximum values at temperatures around 42 C. Arterial Po₂ and hemoglobin saturation did not decrease until rectal temperature exceeded 42 C. Pco₂ decreased and pH increased from control values as minute volume increased. Arterial excess lactate showed the most marked rise at T_rs between 41 and 42 C. Failure of external respiration is not the primary physiological failure during progressive hypothermia but the development of tissue hypoxia may be.

Key Words: excess lactate • body temperature • arterial pO₂ • arterial pCO₂ • arterial pH • respiration in hyperthermia

Submitted on March 18, 1963

This article has been cited by other articles:

				V. P. Satinsky and L. L. Konecke Renal Response To Simulated "Mechanical Heart Hyperthermia" Angiology, May 1, 1970; 21(5): 343 - 348. [PDF]