Cardiac surgery in octogenarians with poor lung function.
Explore the source record for details and available documents.
Aged↗
Biomedical subjects
H J Skinner
Publications and source records attributed to H J Skinner.
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. Partial pressure of the end-tidal carbon dioxide (PE'(CO(2))) and mean arterial pressure were measured throughout the study. Anaesthesia was induced with propofol and was maintained with desflurane at end-tidal concentrations of 7.4% (1 MAC) or 10.8% (1.5 MAC). The order of administration of the desflurane concentrations was determined randomly and a period of 15 min was allowed for equilibration at each concentration. The transient hyperaemic response tests were performed before induction of anaesthesia and after equilibration with each concentration of desflurane. 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.
Adolescent↗
Effect of cricoid pressure on gastro-oesophageal reflux in awake subjects.
This study aimed to evaluate whether cricoid pressure is associated with a high risk of gastro-oesophageal reflux. Fifteen awake, fasted volunteers were studied. A cricoid pressure of 44 N was applied for 60 s by resting a padded yoke over the cricoid cartilage. Using continuous oesophageal pH monitoring, no volunteer had gastro-oesophageal reflux during cricoid pressure, although one subject had a reflux spike soon after relieving cricoid pressure. We conclude with 95% confidence that the incidence of gastro-oesophageal reflux during cricoid pressure is not more than 20%.
Adult↗
Influence of metoclopramide on plasma cholinesterase and duration of action of mivacurium.
Mivacurium is metabolized by plasma cholinesterase (PCHE). Metoclopramide inhibits PCHE in vitro and in vivo. We have assessed the effect of metoclopramide on duration of action of mivacurium and measured PCHE at baseline and at the time of maximal block. In a randomized, double-blind study, 30 patients received metoclopramide 0.15 mg kg-1 i.v. or saline, followed by propofol anaesthesia and mivacurium 0.15 mg kg-1. Using a TOF-Guard accelerometer, times to recovery of TI to 25%, 75% and 90% were 13.4, 19.3 and 21.9 min in the saline group and 17.8, 25.3 and 28.8 min in the metoclopramide group (P < 0.01, P < 0.05, P < 0.05, respectively). There were no differences in onset time or recovery index between the groups. PCHE activity at the time of maximum block decreased within each group (P < 0.01) but there was no difference between groups. In a second biochemical study of eight patients, a small decrease in PCHE activity was detected after metoclopramide 0.15 mg kg-1, but before administration of mivacurium (P < 0.025). We conclude that metoclopramide prolongs the duration of action of mivacurium.
Adult↗
Gastro-oesophageal reflux during day case gynaecological laparoscopy under positive pressure ventilation: laryngeal mask vs. tracheal intubation.
This study aimed to evaluate whether or not the use of intermittent positive pressure ventilation via the laryngeal mask airway is associated with a higher risk of gastro-oesophageal reflux when compared with intermittent positive pressure ventilation via a tracheal tube in patients undergoing day case gynaecological laparoscopy in the head down position. Sixty healthy women were randomly allocated to receive either the laryngeal mask or cuffed tracheal tube for intra-operative airway maintenance. Using continuous oesophageal pH monitoring, four patients in the tracheal tube group and none in the laryngeal mask group had evidence of gastro-oesophageal reflux (as indicated by a decrease in oesophageal pH to below 4). The difference in the incidence of reflux did not achieve statistical significance (p = 0.11). In conclusion, we found no evidence to suggest that the use of intermittent positive pressure ventilation via the laryngeal mask increases the risk of gastro-oesophageal reflux in patients undergoing elective day case gynaecological laparoscopy.
Adult↗
Another angle on LMA stability.
Explore the source record for details and available documents.
Equipment Design↗
Evaluation of intubating conditions with rocuronium and either propofol or etomidate for rapid sequence induction.
We have assessed the effect of two induction agents on tracheal intubating conditions after rocuronium 0.6 mg.kg-1 in unpremedicated patients undergoing simulated rapid sequence induction. Following pre-oxygenation, anaesthesia was induced with propofol up to 2.5 mg.kg-1 (n = 35) or etomidate 0.3 mg.kg-1 (n = 36), and further increments as required. After loss of verbal contact, cricoid pressure was applied and rocuronium was injected. Laryngoscopy was performed at 45 s and intubation attempted at 60 s after rocuronium had been given. Ninety-four per cent of patients in the propofol group had clinically acceptable (good or excellent) intubating conditions compared to only 75% in the etomidate group (p = 0.025). Owing to coughing, one patient in the etomidate group could not be intubated on the first attempt. A greater pressor response also followed intubation after induction with etomidate. We conclude that etomidate and rocuronium alone cannot be recommended for intubation at 60 s under rapid sequence induction conditions.
Adolescent↗
Gastro-oesophageal reflux with the laryngeal mask during day-case gynaecological laparoscopy.
We have evaluated if breathing spontaneously via a laryngeal mask airway is associated with a higher risk of gastro-oesophageal reflux compared with positive pressure ventilation via a laryngeal mask airway in 40 patients undergoing day-case gynaecological laparoscopy. Patients were allocated randomly to receive either positive pressure ventilation or breathe spontaneously via a laryngeal mask airway. Using continuous oesophageal pH monitoring, three patients in the ventilated group and one in the spontaneous breathing group had gastrooesophageal reflux (P = 0.29). We found no evidence to suggest that breathing spontaneously via a laryngeal mask airway increased the risk of gastro-oesophageal reflux compared with positive pressure ventilation in this group of patients.
Adult↗