The haemodynamic and catecholamine response to xenon/remifentanil anaesthesia in Beagle dogs

Abstract

SummaryThe noble gas xenon seems to have minimal cardiovascular side-effects and so may be an ideal anaesthetic agent when investigating cardiovascular physiology. In comparison with standard modern anaesthetics, we investigated the haemodynamic and hormonal effects of xenon in Beagle dogs. After a 30 min baseline period, anaesthesia was induced with propofol and maintained with either (1) 1.2% isoflurane/70% nitrous oxide (N 2 O), (2) 0.8% isoflurane/ 0.5 mg/kg/min remifentanil or (3) 63% xenon/0.5 mg/kg/min remifentanil (n ¼ 6 per group).Haemodynamics were recorded and blood samples taken before and 60 min after induction. Mean arterial blood pressure (MAP) was higher in conscious dogs than during isoflurane/N 2 O (86 + 2 vs. 65 + 2 mmHg, mean + SEM) and isoflurane/remifentanil anaesthesia (95 + 2 vs. 67 + 3 mmHg), whereas MAP did not decrease significantly in response to xenon/ remifentanil anaesthesia (96 + 4 vs. 85 + 6 mmHg). Bradycardia was present during isoflurane/remifentanil (54 + 2/min) and xenon/remifentanil (40 + 3/min), but not during isoflurane/N 2 O anaesthesia (98 + 3/min, P , 0.05). Xenon/remifentanil anaesthesia induced the highest reduction in cardiac output (CO) ( -61%), and the highest increase in systemic vascular resistance (þ120%) among all treatment groups (P , 0.05). A simultaneous increase in endogenous adrenaline and noradrenaline concentrations could only be observed in the xenon/remifentanil group, whereas angiotensin II and vasopressin concentrations increased in all groups. In conclusion, xenon/remifentanil anaesthesia maintains MAP but reduces heart rate and CO and is associated with a considerable stimulation of vasopressor hormones in Beagle dogs. Therefore, xenon/remifentanil exerts a new quality of adverse haemodynamic effects different from volatile anaesthetics and may not perform better during studies of cardiovascular physiology.

Endothelin receptor subtype A blockade does not affect the haemodynamic recovery from haemorrhage during xenon/remifentanil or isoflurane/remifentanil anaesthesia in dogs

“…A fraction of the results reported here overlap with data in previous publications (Francis et al. 2006, 2008; Höhne et al.…”

“…For improved readability, error bars are unilateral, and indicators of significance (see Table 1) are omitted. Part of the awake and anaesthesia baseline data in controls and after ET A blockade in all Figures and Tables has been published previously (Francis et al. 2006, 2008; Höhne et al.…”

“…The present study is part of a much wider investigation into the effects of ET A receptor blockade, angiotensin II receptor blockade, or both; their influence in the response to haemorrhage and if these changes are altered by the anaesthetic regimen in use (Höhne et al. 2004, 2008; Francis et al. 2006, 2008).…”

Xenon offers stable haemodynamics independent of induced hypothermia after hypoxia–ischaemia in newborn pigs

“…Xe 60% has been associated with better left ventricular performance [26] and systolic function [27] in patients with moderate cardiovascular risk [26] and ischaemic heart disease [27], respectively. Other possible mechanisms for maintaining stable MABP may be due to the preservation of the systemic vascular resistance and myocardial contractility following inhalation of Xe 50-70% in pigs [25], Xe 63% in dogs [28], and Xe 15-53% in humans who underwent coronary artery bypass grafts [29]. This could explain Xe's ability to maintain MABP 10.1 mmHg higher during rewarming, when the systemic vascular resistance is likely to fall [30].…”

Avaliação da concentração expirada de isoflurano em infusão continua de remifentanil em cadelas submetidas a mastectomia

“…Monteiro et al (2011) used a different constant rate of remifentanil infusion and obtained similar results to those of this study, including decreased heart rate and cardiac index and stable arterial pressure (although a significant increase in arterial blood pressure was observed with the higher infusion rate of remifentanil (0.9 µg kg -1 min -1 )), which can be explained by an increase in the systemic vascular resistance index, which is correlated with an increase in vasopressin level. Francis et al (2008) also found that remifentanil in combination with inhalation anesthetics can cause bradycardia and decrease cardiac output, but it can also increase systemic vascular resistance up to 120% through stimulation of vasopressors, such as angiotensin II and vasopressin, to maintain arterial blood pressure at normal values in dogs. Allweiler et al (2007) observed higher values of arterial blood pressure in animals treated with remifentanil than in the control group.…”