Effects of Althesin on Cerebral Blood Flow and Oxygen Consumption in Man

Abstract

Cerebral circulation and metabolism during Althesin anaesthesia were studied in seven healthy patients. Althesin was given in a single dose of 0.1 ml/kg and thereafter infused at a constant rate of 0.3 ml/kg/h. During Althesin infusion, the cerebral blood flow (CBF), the cerebral metabolic rate for oxygen (CMRo2) were 29 +/- 10 ml/100 g/min and 1.7 +/- 0.4 ml/133 g/min, respectively. These values were significantly different from those obtained in awake subjects in our laboratory (CBF: 46 +/- 7 ml/100 g/min; CMRo2: 3.1 +/- 0.6 ml/100 g/min). During CBF measurement, the mean cerebral perfusion pressure, cerebral vascular resistance (CVR) and arterial carbon dioxide tension (PaCO2) were 89 +/- 16 mm Hg, 3.4 +/- 1.3 mm Hg/ml/100 g/min, and 36 +/- 9 mm Hg, respectively. The relationship between CBF and PaCO2 were studied and it was found that during Althesin anaesthesia reactivity of cerebral vessels to the alteration of PaCO2 was maintained. It is concluded that Althesin caused cerebral metabolic depression which was accompaned by a decrease in CBF and an increase in CVR.

Effects of sevoflurane and isoflurane on the ratio of cerebral blood flow/metabolic rate for oxygen in neurosurgery

“…At 0.5 and 1.0 MAC, the present results demonstrated no significant differences in the global CBF relative to CMRo 2 between the two drugs. Although we did not compare the values of CBF equivalent with those in the awake condition in the present study, the values at 0.5 and 1.0 MAC with both anesthetics are greater than those of awake patients reported with the use of the same technique [8].…”

Cerebral Blood Flow and Metabolism During Etomidate Anaesthesia in Man

“…Similar decreases have been reported following the administration of most i.v. anaesthetic drugs, for example thiopentone (Pierce et al, 1962), Innovar (Michenfelder and Theye, 1971), diazepam (Cotev and Shalit, 1975) and Althesin (Renou et al, 1976;Sari et al, 1976). On the other hand, ketamine (Simard, 1975) and most inhalation anaesthetic agents such as cyclopropane (Alexander et al, 1968) and halothane (Smith and Wollman, 1972) increase c.b.f.…”

Rhesus immunisation during pregnancy: the case for antenatal anti-D.

“…Althesin is a steroid intravenous anaesthetic agent used in an infusion to provide total intravenous anaesthesia by virtue of its short action and minute-to-minute control of the depth of narcosis.3 It is also used in neurosurgery to reduce the cerebral oxygen consumption, cerebral blood flow, and, therefore, intracranial pressure. 4 We have used it in our ITU for severe head injuries. In addition, the solution provides the main daily fluid input.…”