British journal of anaesthesia
-
Randomized Controlled Trial Clinical Trial
Effects of desflurane on cerebral autoregulation.
The aim of this study was to determine the effects of desflurane, at 1 and 1.5 MAC, on cerebral autoregulation. Data were analysed from eight patients undergoing non-neurosurgical procedure. The blood flow velocity in the middle cerebral artery was measured by transcranial Doppler ultrasound and cerebral autoregulation was assessed by the transient hyperaemic response test. ⋯ An infusion of phenylephrine was used to maintain pre-induction mean arterial pressure and ventilation was adjusted to maintain the pre-induction value of PE'(CO(2)) throughout the study. Two indices derived from the transient hyperaemic response test (the transient hyperaemic response ratio and the strength of autoregulation) were used to assess cerebral autoregulation. Desflurane resulted in a marked and significant impairment in cerebral autoregulation; at concentrations of 1.5 MAC, autoregulation was almost abolished.
-
Randomized Controlled Trial Clinical Trial
Influence of nitrous oxide on induction of anaesthesia with sevoflurane.
Nitrous oxide is often used during inhalation induction of anaesthesia with sevoflurane. Although the value of using nitrous oxide during inhalation induction with other volatile anaesthetics has been studied, the popularity of sevoflurane induction and the different characteristics of this agent make a study of the combination of nitrous oxide with this agent of interest. We compared induction times, oxygenation, and excitatory events during inhalation induction of anaesthesia using sevoflurane, with and without nitrous oxide. ⋯ Mean time to induction of anaesthesia (fall of an outstretched arm) was 102 s in both groups, but excitation (limb or head movement) was more frequent in those receiving nitrous oxide (10 patients) than in those receiving oxygen only (five patients) (P<0.05). Oxygenation was similar in both groups. We conclude that nitrous oxide confers no advantage when anaesthesia is induced with sevoflurane in this way.
-
Cardiac tamponade is a poorly recognized complication of central venous catheterization associated with a high mortality. We present a case of fatal cardiac tamponade after intra- pericardial infusion of total parenteral nutrition in a patient who had two central venous catheters. We suggest that catheter tip position should always be confirmed before use of a catheter. Tamponade should be suspected in a patient who deteriorates when a central venous catheter is used and resuscitation via the catheter should be avoided.
-
Case Reports
Ipsilateral thoraco-lumbar anaesthesia and paravertebral spread after low thoracic paravertebral injection.
We report ipsilateral thoraco-lumbar anaesthesia and paravertebral spread of contrast after injection through a thoracic paravertebral catheter that was placed at the right T8-9 spinal level for pain management in a patient with multiple fractured ribs. We review the literature and describe the subendothoracic fascial communication between the thoracic paravertebral space and the retroperitoneal lumbar paravertebral region, which we propose, is the anatomical basis for ipsilateral thoraco-lumbar anaesthesia and paravertebral spread of contrast in our patient.
-
Perioperative levels of jugular bulb oxyhaemoglobin saturation (Sj(O(2))) and lactate concentration (Lj), and postoperative duration of Sj(O(2))<50% were compared between patients undergoing coronary artery bypass grafting (CABG) (n=86), heart valve (n=14) and abdominal aortic (n=16) surgery. Radial artery and jugular bulb blood samples were aspirated after induction of anaesthesia, during re-warming on cardiopulmonary bypass (CPB) (36 degrees C), on arrival in the intensive care unit (ICU) and, subsequently, at 1, 2 and 6 h after ICU admission. Most patients having heart surgery were hypocapnic at 36 degrees C on CPB. ⋯ Following correction for La, there were no postoperative effects on Lj. No significant differences (P=0.2) in duration of Sj(O(2))<50% existed between patients undergoing CABG (1054 (82) min), abdominal aortic (893 (113) min) and heart valve (1073 (91) min) surgery. The lack of significant reciprocal effects on Lj combined with the frequency of hypocapnia and strong influence of Pa(CO(2))()on Sj(O(2)), suggest that Sj(O(2))<50% during CPB and after cardiac surgery represents hypoperfusion as a consequence of hypocapnia rather than cerebral ischaemia.