In:
American Journal of Physiology-Heart and Circulatory Physiology, American Physiological Society, Vol. 286, No. 5 ( 2004-05), p. H1811-H1820
Abstract:
Studies are needed to provide a rigorous examination of the relevance of monitored variables during prolonged hemorrhagic hypotension (HH). This study was designed to investigate the parameters that describe biochemical and O 2 transport patterns in animals subjected to HH. Systemic parameters that could differentiate survivors from nonsurvivors were identified. An aortic flow probe was implanted in rats ( n = 21) for continuous measurement of cardiac output. Experiments were performed 6–9 days after surgery. Rats were bled to a mean arterial pressure of 40 mmHg and kept at that level using Ringer-lactate solution. Arterial and venous blood pressures, gases, acid-base status, glucose, lactate, electrolytes, hemoglobin, O 2 saturation, heart and respiratory rates, total peripheral resistance, and O 2 delivery and consumption were measured before hemorrhage, soon after 40 mmHg was reached, and 0.5, 1, 2, 3, and 4 h later. Fifty-three percent of rats survived ≥3 h (survivors); others were considered nonsurvivors. Nonsurvivors showed a significantly greater degree of metabolic acidosis than survivors. Arterial Po 2 , respiratory rate, O 2 saturation, O 2 content, glucose, and pH were significantly higher in survivors. The rate of Ringer-lactate infusion, arterial K + , and Pco 2 were lower in survivors. Arterial K + and respiratory rate were the only parameters significantly different between survivors and nonsurvivors at all time points during HH. Arterial levels of K + showed the clearest distinction between survivors and nonsurvivors and may explain the sudden death experienced by animals during HH. The data suggest that early respiratory and metabolic compensations are essential for survival of prolonged HH.
Type of Medium:
Online Resource
ISSN:
0363-6135
,
1522-1539
DOI:
10.1152/ajpheart.00837.2003
Language:
English
Publisher:
American Physiological Society
Publication Date:
2004
detail.hit.zdb_id:
1477308-9
SSG:
12
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