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J A Murdoch

Publications and source records attributed to J A Murdoch.

7 recordsLinked to original sources
PubMed2001

Anesthesia for hysteroscopy.

Hysteroscopy is becoming a more widely used technique. Diagnostic hysteroscopy is replacing conventional dilatation and curettage in the diagnosis of intrauterine pathologies. Transcervical endometrial resection is often the first-line surgical treatment for dysfunctional uterine bleeding and carries less associated morbidity and morality. Overall, the technique is extremely safe, but vigilance is required particularly for intravasation of irrigation media. Complications such as gas embolus and hypo-osmolar hyponatremia require prompt treatment to reduce associated morbidity and morality. Careful monitoring of fluid deficit is paramount in avoiding the latter problem. Regional or general anesthetic techniques can be used and, in the ambulatory or office-based setting, in which these procedures are increasingly performed, the need for "street readiness" can influence the choice of the agents used.

Anesthesia↗
PubMed2000

Safety of patient-maintained propofol sedation using a target-controlled system in healthy volunteers.

We investigated the safety of a patient-maintained system that allows individuals to operate a target-controlled infusion of propofol to achieve sedation. Ten healthy volunteers were recruited and instructed to try to anaesthetize themselves with the system. A target-controlled infusion of propofol was set to deliver a target propofol concentration of 1 microgram ml-1, and the subjects allowed to increase the target in increments of 0.2 microgram ml-1 by pressing a control button twice in 1 s. There was a lockout time of 2 min and a maximum permitted target concentration of 3 micrograms ml-1. Heart rate and pulse oximetry oxygen saturation (SpO2) were monitored continuously, and non-invasive arterial pressure, ventilatory frequencies and sedation scores were measured every 5 min. Sedation was continued until the subject stopped pressing the button. A keyword was then read for the individual to remember and sedation discontinued. There were no instances of significant decrease of SpO2 or loss of airway control. Maximum target blood concentration of propofol recorded ranged from 1.4 to 3 micrograms ml-1. Two subjects became oversedated, one of whom was unrousable with loss of eyelash reflex. No subject could recall the keyword, although one recognized it from a list of 10 words. We conclude that the patient-maintained sedation system described could not be guaranteed to produce only conscious sedation in all patients, and that close clinical supervision by an anaesthetist would still be required for safe operation.

Adolescent↗
PubMed1999

Target-controlled remifentanil in combination with propofol for spontaneously breathing day-case patients.

Remifentanil is a new potent opioid with a very short duration of action irrespective of duration of infusion. It may have a role in day-case anaesthesia as part of a balanced total intravenous anaesthetic technique with propofol. We examined the respiratory depressant effects of remifentanil in 20 patients undergoing day-case anaesthesia. The target plasma concentration of remifentanil was varied while maintaining a constant target-controlled infusion of 4.5 microg x ml-1 propofol. In only 12 patients was satisfactory spontaneous respiration maintained. In these patients the median remifentanil target concentration was 1.6 ng x ml-1 and was achieved with a median infusion rate of 0.05 microg x kg-1 x min-1. The range of target concentrations associated with satisfactory spontaneous respiration was wide and varied over a 4.7-fold range from 0.6 to 2.8 ng x ml-1.

Adult↗
PubMed1999

Patient-maintained propofol sedation as premedication in day-case surgery: assessment of a target-controlled system.

We have assessed the efficacy and safety of a system which allowed 20 patients undergoing day-case anaesthesia to operate a target-controlled infusion of propofol to provide anxiolytic premedication. A target-controlled infusion of propofol was started with a target blood concentration of 1 microgram ml-1, and the patient was allowed to increase the target by 0.2 microgram ml-1 by operating a control button. There was a lockout time of 2 min and a maximum target concentration of 3 micrograms ml-1. There were significant reductions in anxiety scores from presedation baseline values and those measured at 15 min after the start of sedation. Values remained low until induction of anaesthesia. Median blood target concentration of propofol varied from 1.0 to 1.2 micrograms ml-1 and mean propofol consumption was 50.3 (SD 17.6) micrograms kg-1 min-1. No patient became oversedated and all remained cardiovascularly stable. Two individuals required low-dose supplementary oxygen for mild arterial oxygen desaturation but there were no instances of airway obstruction. Patient satisfaction with the system was high.

Adolescent↗