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Biomedical subjects

P M Weir

Publications and source records attributed to P M Weir.

8 recordsLinked to original sources
PubMed2000

Reducing stress responses in the pre-bypass phase of open heart surgery in infants and young children: a comparison of different fentanyl doses.

High-dose opioids are advocated for paediatric cardiac surgery to suppress stress responses but they can produce unwanted side effects. There are no data on the dose-dependent effects of opioids on the stress response on which to base rational opioid administration. We conducted a dose ranging study on 40 children less than 4 yr undergoing elective open heart surgery using one of five fentanyl doses: 2, 25, 50, 100 or 150 micrograms kg-1 before surgery. The standardized anaesthetic also included pancuronium and isoflurane. Blood samples were taken at induction, before incision, after sternotomy, immediately before, and at the end of cardiopulmonary bypass. Patients in the 2 micrograms kg-1 group had significant rises in prebypass glucose (P < 0.01), pre- and post-bypass cortisol (P < 0.01), and pre- and post-bypass norepinephrine (P < 0.01). No significant rise occurred in glucose, cortisol and catecholamines in any of the higher dosage groups. Patients in the 2 micrograms kg-1 group had significantly higher mean systolic blood pressure (P < 0.02) and heart rate (P < 0.04). A balanced anaesthetic containing fentanyl 25-50 micrograms kg-1 is sufficient to obtund haemodynamic and stress responses to the pre-bypass phase of surgery. Higher doses of fentanyl (100 and 150 micrograms kg-1) offer little advantage over 50 micrograms kg-1, and can necessitate intervention to prevent hypotension.

Anesthesia, General↗
PubMed1997

Regional anaesthesia for circumcision. Subcutaneous ring block of the penis and subpubic penile block compared.

In this prospective study techniques for the subcutaneous ring block of the penis and subpubic block of the penis for analgesia after circumcision were compared. Forty-five boys having circumcision as day-case patients were allocated randomly to have either a subcutaneous ring block or a subpubic penile block. The blocks were inserted after induction of anaesthesia but before surgery. Pain scores at 15, 30, 45 and 60 min post-operatively were recorded. Side effects and analgesic requirements in hospital were recorded post-operatively. Analgesia (morphine, paracetamol or diclofenac) was given depending on the pain score. One patient was withdrawn from the study. Four of the 24 boys who had subpubic penile blocks and nine of the 16 boys who had subcutaneous ring blocks were given morphine for post-operative pain (P = 0.015). The surgeons complained about oedematous tissues in three patients, all of whom had had subcutaneous ring blocks. The subpubic penile block provided significantly better analgesia than the subcutaneous ring block of the penis.

Child, Preschool↗
PubMed1993

Propofol infusion and the incidence of emesis in pediatric outpatient strabismus surgery.

A prospective, randomized, double-blind study was conducted to examine the effect of a propofol infusion on the incidence of postoperative emesis in children undergoing outpatient strabismus surgery. Seventy-eight children, aged 3-12 yr, were allocated randomly to receive either nitrous oxide and halothane or nitrous oxide and a propofol infusion for the maintenance of anesthesia. The overall incidence of vomiting during the first 24 h was 64% in those receiving halothane and 41% in those receiving the propofol infusion; this difference was statistically significant (P < 0.05). In children who received no opioids postoperatively, the incidence of vomiting in the first 24 h was 71% in the halothane group and 24% in the propofol group; this difference was also significant (P = 0.001). We conclude that propofol was effective in reducing the incidence of postoperative emesis in pediatric outpatient strabismus surgery.

Anesthesia↗
PubMed1991

Are you getting the message? A look at the communication between the Department of Health, manufacturers and anaesthetists.

A questionnaire sent to 109 anaesthetists in the South West Region has revealed that there is a problem with dissemination of information relating to hazards with equipment. Thirty-four per cent of consultants, and 67% of junior anaesthetists were only slightly or not at all confident that they see the Hazard Notices and Safety Action Bulletins relating to the equipment they use. The study has also demonstrated the large amount of new equipment coming into circulation and has highlighted deficiencies in the reading of equipment manuals. Some suggestions are made as to how the current system may be improved.

Anesthesiology↗
PubMed1988

Is propofol a safe agent in porphyria?

A case is presented of the use of a propofol infusion for anaesthesia in a patient with known variegate porphyria. Urinary screening for porphyrins demonstrated a marked increase after this anaesthetic, but there were no clinical symptoms.

Adult↗