Acta anaesthesiologica Scandinavica
-
Acta Anaesthesiol Scand · Jan 1978
Arterial oxygenation during artificial ventilation. The effect of airway closure and of its prevention by positive end-expiratory pressure.
Airway closure and arterial blood gases were measured in 11 healthy subjects both before and during anaesthesia with artificial ventilation, prior to routine surgery. The functional residual capacity was then increased by positive end-expiratory pressure (PEEP), so that ventilation took place at a lung volume where no airway closure was present, and the effect on arterial oxygenation was again investigated. ⋯ There was no improvement in arterial oxygenation on increasing functional residual capacity (FRC) in either group. It may well be that this failure to improve oxygenation was due to a deleterious effect of PEEP on the circulation, even though the PEEP was the minimum required to abolish airway closure.
-
Pre- and preoperative determination of glomerular filtration rate (GFR) was performed in 10 patients operated on during enflurane anaesthesia. The mean GFR decreased significantly by 21%. The decrease in GFR is of the same order of magnitude as that reported for most general anaesthetics.
-
Acta Anaesthesiol Scand · Jan 1977
Peripheral nerve injury due to injection needles used for regional anesthesia. An experimental study of the acute effects of needle point trauma.
Nerve injury can arise as a complication peripheral nerve block anesthesia. Of the various factors involved, the trauma caused by the injection needle may be of significance. ⋯ Fascicular injury was indicated by a fluorescence microscopy technique, tracing locally applied Evans Blue Albumin, The results show that a 45 degrees-beveled needle less frequently produces fascicular damage and should therefore be recommended for use in clinical anesthesia. It is also concluded that paresthesiae, when necessary, should be elicited gently, and that intraneural injections should be avoided.
-
Acta Anaesthesiol Scand · Jan 1977
Comparative StudyThe cerebrovascular CO2 reactivity during the acute phase of brain injury.
Using the intra-arterial 133xenon (133Xe) method, the cerebrovascular response to acute Paco2 reduction was studied in 26 unconscious, brain-injured patients subjected to controlled ventilation. The CO2 reactivity was calculated as delta in CBF/delta Paco2. The perfusion pressure was defined as the difference between mean arterial pressure and mean intraventricular pressure. ⋯ An increase of the CO2 reactivity with time was observed, indicating normal response after 1-2 weeks. Chronic hypocapnia in six unconscious patients resulted in sustained CSF pH adaptation. The question whether a delay in CSF pH adapation exerts an influence on the CO2 reactivity, and the influence of cerebral lactacidosis on the CO2 response are discussed.
-
Acta Anaesthesiol Scand · Jan 1977
Comparative StudyHuman hepatic blood flow and its relation to systemic circulation during intravenous infusion of bupivacaine or etidocaine.
Fifteen healthy young volunteers were studied before and during an intravenous infusion of a local anaesthetic agent. Seven received bupivacaine and eight etidocaine in a dose rate of 2 mg/min over a period of 150 min. Variables of the central systemic circulation and also the hepatic blood flow were measured repeatedly. ⋯ In contrast, these three drugs had the same decreasing effect upon the splanchnic vascular resistance, which caused an almost identical increase in the estimated hepatic blood flow. The calculated vascular resistance in the systemic circulation, excluding the splanchnic, was unchanged during the infusion of etidocaine, while it decreased during the infusion of bupivacaine. Most of this discrepancy was due to the different plasma concentrations of the drugs.