Pulmonary Vascular Response to Increasing Cardiac Index following Systemic Hypotension Is Modified by Pentobarbital Anesthesia

Abstract

We examined the effect of sodium pentobarbital (PB) anesthesia on the pulmonary vascular response to increasing cardiac index (CI) following systemic hypotension (H). The pulmonary vascular pressure gradient (pulmonary arterial-pulmonary capillary wedge pressure:AP) was measured at multiple levels of CI (ml/min/kg) during stepwise inflation and deflation of an inferior vena cava (IVC) occluder in 10 conscious dogs, and again during PB anesthesia (30 mg/kg, iv). Maximum IVC constriction decreased (p<0.01) CI (131 ± 9 to 46 ± 4 vs 120 ± 8 to 39 ± 4) and systemic arterial pressure (113 ± 2 to 51 ± 2 mmHg vs 94 ± 4 to 47 ± 2 mmHg) in conscious and PB dogs, respectively. Following 15 rain of H, CI was gradually increased by deflation of the IVC occluder. Compared to values obtained during inflation of the IVC occluder, AP was not significantly changed at any level of CI following H in conscious dogs. For example, δP was 6.0 ± 0.5 mmHg before and 6.0 ± 0.6 mmHg after H at CI = 60, and 11.7 ± 0.7 mmHg before and 11.8 ± 0.8 mmHg after H at CI - 120. In contrast, pulmonary vasoconstriction was observed following H during PB, i.e. ΔP was increased (p<0.01) 24 ± 5% from 6.1 ± 0.4 mmHg at CI - 60, and 30 ± 7% from 10.5 ± 0.6 mmHg at CI = 120. Thus, pulmonary vascular regulation following H is altered by PB anesthesia.

DOI: 10.1203/00006450-198704010-00234

Cite this paper

@article{Nyhan1987PulmonaryVR, title={Pulmonary Vascular Response to Increasing Cardiac Index following Systemic Hypotension Is Modified by Pentobarbital Anesthesia}, author={Daniel P Nyhan and Bessie B Chen and Harold M Coll and Patrick W Clougherty and Paul A. Murray}, journal={Pediatric Research}, year={1987}, volume={21}, pages={205A-205A} }