Accession Number:

AD0289285

Title:

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

Descriptive Note:

Corporate Author:

SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TEX

Report Date:

1962-06-01

Pagination or Media Count:

1.0

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 13 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

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE