Accession Number : AD0289285

Title :   MECHANISMS OF HYPERVENTILATION IN MAN. CARBON DIOXIDE AND ACID-BASE TRANSIENTS DURING HYPERVENTILATION. RECOVERY FROM ACUTE HYPERVENTILATION

Corporate Author : SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX

Personal Author(s) : TOMASHEFSKI,JOSEPH F. ; CARTER,EARL T. ; LIPSKY,JOSEPH A.

Report Date : JUN 1962

Pagination or Media Count : 1

Abstract : Studies were conducted on ten healthy adult males subjected to mechanically induced hyperventilation. Total ventilation was increased approximately 300%. This resulted in a mean arterial CO2 tension decrease to 20 mm. Hg and a mean pH increase to 7.60. Observations of the dynamic shifts in CO2 stores were made for a 12-minute period after the onset of hyperventilation. The total CO2 elimination was determined and compared to the basic metabolic CO2 production to permit estimation of body CO2 depletion. In a second experiment 14 male subjects were mechanically hyperventilated by intermittent positive-pressure breathing. Tidal volume and respiratory frequency were increased approximately three times and one and one-half times control, respectively. Expired air was monitored continuously, and arterial blood was collected frequently during 12-minute periods of hyperventilation and recovery. Breath-by-breath analyses indicate a loss of approximately 2.5 liters of CO2 from the body stores during hyperventilation. Only 1/3 of that volume was restored during the ensuing recovery period, mostly as a result of hypoventilation rather than apnea. Over the entire recovery period, the volume of CO2 regained by the arterial blood represented approximately 75% of the CO2 content lost during hyperventilation. (Author)

Descriptors :   *CARBON DIOXIDE, *OXYGEN, *POISONING, *RESPIRATION, ACID BASE EQUILIBRIUM, ARTERIES, BLOOD, HYPOXIA, LUNG, TISSUES (BIOLOGY)

Distribution Statement : APPROVED FOR PUBLIC RELEASE