Physiologic responses and plasma endothelin-1 concentrations associated with abrupt cessation of nitric oxide inhalation in isoflurane-anesthetized horses

Abstract

The improvement in arterial oxygenation during pulsed inhalation of NO to healthy isoflurane-anesthetized horses decreased only gradually during a 30-minute period following cessation of NO inhalation, and serum ET-1 concentration was not affected. Because a rapid rebound response did not develop, inhalation of NO might be clinically useful in the treatment of hypoxemia in healthy isoflurane-anesthetized horses.

Oxygenation and plasma endothelin‐1 concentrations in healthy horses recovering from isoflurane anaesthesia administered with or without pulse‐delivered inhaled nitric oxide

“…These results are similar to those from previous studies in which iNO was discontinued while the horses were still receiving isoflurane and 100% oxygen (Heinonen et al. 2001, 2002; Grubb et al. 2008).…”

“…1991), thus horses might have a different susceptibility to a rebound response; 2) the delivery of iNO by pulses rather than continuously since continuous delivery is the existing ‘gold standard’ in human medicine and pulse delivery is currently reported only in horses (Heinonen et al. 2001, 2002; Grubb et al. 2008) and all other studies used continuous delivery of iNO; and 3) the health of study animals since healthy horses were used in this study and many of the studies describing the rebound reflex were in compromised study subjects or patients (Chen et al.…”

“…2002; Wagner 2009) and any factors that further jeopardized the recovery period would be unacceptable. Previously, Grubb et al. (2008) demonstrated that a rebound effect does not occur when iNO administration is discontinued in dorsally recumbent horses continuing to be maintained on isoflurane and oxygen.…”

Pulsed delivery of inhaled nitric oxide counteracts hypoxaemia during 2.5 hours of inhalation anaesthesia in dorsally recumbent horses

“…The response to iNO was immediate and lasted during 2.5 hours delivery without measured adverse physiological effects. After cessation of continuous pulse‐delivered iNO, arterial oxygen tension and shunt gradually returned to baseline values (Grubb et al. 2008).…”

Added Value with Extended NO Analysis

“…(11.9): C A NO corrected = (C A NO − 0.08 · F E NO 0.05 )/0.92 (11.9) Endogenous NO from the upper and lower airways is transported into the alveolar region. 38 Seen from a physiological viewpoint, the movement of NO by axial diffusion is therefore not an optimal solution. This endogenous inhalation of NO in the ppb range is known to increase oxygenation.…”