Anaesthesia
-
Total intravenous anaesthesia may be most beneficial for day-case surgery with regard to quality of recovery, lack of complications and the ability to sustain an efficient throughput of patients. However, the technique can be applied to all forms of surgery and, with a little practice, consistent results will be achieved. ⋯ The commercially available 'Diprifusor', a target controlled infusion system for propofol, can facilitate the more widespread use of total intravenous techniques and allow their potential benefits to be applied and appreciated more widely. This review outlines some practical considerations that should enable a more confident approach to total intravenous techniques by anaesthetists who are unfamiliar with them.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of the effect of EMLA and semicircular subcutaneous anaesthesia in the prevention of tourniquet pain during plexus block anaesthesia of the arm.
In 54 patients who were to undergo surgery of the upper extremity in plexus block anaesthesia the effect of 5 g EMLA (group E) on tourniquet pain was examined and compared with the effect of a semicircular subcutaneous anaesthesia using 10 ml 0.25% bupivacaine (group B) or 10 ml 1% mepivacaine (group M). Among the patients with satisfactory brachial plexus analgesia allowing for surgery (n = 51), the incidence of tourniquet pain was not significantly different between groups E, M and B. Notably, there was no significant difference in the time of tourniquet application. We conclude that topical application of EMLA is as effective as a semicircular subcutaneous anaesthesia with mepivacaine or bupivacaine in the prevention of tourniquet pain during brachial plexus anaesthesia.
-
The 'Diprifusor' target controlled infusion system has been developed as a standardised infusion system for the administration of propofol by target controlled infusion. A preferred set of pharmacokinetic parameters for propofol was selected using computer simulation of a known infusion scheme with pharmacokinetic parameters described in published literature. The selected model was included in a 'Diprifusor' module that was interfaced with, and later incorporated into, a computer-compatible infusion pump. ⋯ Standardisation of the delivery performance (+/- 5%) of commercial systems has been achieved with a laboratory performance specification. Clinical studies indicate that the actual blood concentrations achieved were about 16% greater than the calculated values displayed by the system. In an individual patient, titration of the target concentration is required in the same manner as an anaesthetic vapouriser is adjusted to obtain a specific pharmacodynamic effect.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Postoperative respiratory function in children after abdominal surgery. A comparison of epidural and intramuscular morphine analgesia.
Thirty children undergoing urological and abdominal surgery were entered into a randomised trial comparing the effects of epidural and intramuscular morphine on postoperative respiratory function. The forced vital capacity and the forced expired volume in 1 s were measured before and 6 h after surgery and on each of the following seven days. Significant decreases (p < 0.01) in forced vital capacity and forced expired volume in 1 s were seen after surgery. ⋯ There were no statistically significant differences between the two groups during the study with respect to forced vital capacity and forced expired volume in 1 s. The quality of analgesia was better in the epidural morphine group than in the intramuscular morphine group. The incomplete recovery of pulmonary function suggests that pain is not the only cause of postoperative respiratory changes in these patients.
-
Review Case Reports
Recurrent respiratory depression after total intravenous anaesthesia with propofol and alfentanil.
Since first commented upon by Lamarche in 1984, several cases of recurrent respiratory arrest after alfentanil infusions have been reported. In all these cases the alfentanil infusions have been used to supplement conventional anaesthetic techniques with nitrous oxide and/or inhalational agents and in most cases rather high total alfentanil doses have been administered. We have seen two cases of severe recurrent respiratory depression in healthy patients after relatively minor procedures performed under total intravenous anaesthesia with propofol-alfentanil infusions, air-oxygen ventilation and muscle relaxation, where the alfentanil doses administered were quite small. These cases are presented in detail and compared within a tabulated presentation with the earlier published cases of alfentanil-related recurrent respiratory depression.