Cerebral and regional organ perfusion in pigs during xenon anaesthesia

Abstract

Little is known about the haemodynamic effects of inhaled xenon on regional organ perfusion. The aim of this study was to investigate the effect of 79% xenon ventilation on organ perfusion in pigs. We investigated 10 pigs, which were randomly allocated to receive either xenon 79% or total intravenous anaesthesia (TIVA)/oxygen anaesthesia. Microspheres were used to determine organ perfusion. The following regions of interest were investigated: cerebral cortex, medulla oblongata, brainstem, cerebellum, liver, kidney, small intestine, colon, muscle, skin and heart. The results demonstrated a significant increase in regional perfusion in the brainstem (+63%), cerebral cortex (+38%), medulla oblongata (+35%) and cerebellum (+34%). All other organs showed no significant change in regional perfusion. We conclude that xenon should be used with caution in clinical situations associated with pathological increases in intracranial pressure, e.g. neurosurgical procedures, head injury, cerebral mass lesions or stroke.

Xenon for induction of anaesthesia

“…Clinically, similar excitation phases are well known for older, less potent, anaesthetics, but may be seen briefly on slow induction with contemporary anaesthetics. An increased cerebral blood flow under the influence of xenon has previously been described in experimental animal studies, 3 and similar results are found in human research with ketamine 4 . Likewise, the stimulating effect of ketamine on the cardiovascular system is well known in clinical practice.…”

Establishment of a porcine right ventricular infarction model for cardioprotective actions of xenon and isoflurane

“…Because measurement of anesthetic depth is more difficult in animals than in humans, reaching comparable levels using different anesthetic regimes is more complicated. Although 0.55 MAC xenon leads to a 50% reduction of concomitant barbiturate and opioid dosage, as adjusted by equal bispectral EEG levels 32,33 the anesthetic depth might be variable. Differences in hypnotic effects and suppression of reflexes to noxious stimulation and circulatory changes are making validated comparisons nearly impossible.…”

“…2). The reduction of the thiopental infusion dose in the latter two groups to 50% of the initial value (7.5 mg/kg/h) to obtain comparable levels of anesthesia and analgesia was geared to the studies of Schmidt et al 32 and Marx et al 33 using electroencephalograph (EEG)‐based techniques to monitor the depth of anesthesia. After 60 min of adjunct therapy with xenon or isoflurane, the RCA was occluded.…”

Xenon: from stranger to guardian

“…Xenon is not 'inert' with respect to cerebral haemodynamics; increased cerebral blood flow [37][38][39] with preserved cerebral autoregulation [38][39][40] is thought to occur acutely with xenon administration. However, in animals an increase in intracranial pressure with xenon administration has not been reported, despite documented cerebral vasodilatation [41].…”