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Biomedical subjects

A R Dennis

Publications and source records attributed to A R Dennis.

6 recordsLinked to original sources
PubMed1997

The minimum effective doses of pethidine and doxapram in the treatment of post-anaesthetic shivering.

This study was designed to find the minimum effective doses of doxapram and pethidine to stop post-anaesthetic shivering. Two hundred and twenty healthy patients who shivered following routine surgery were allocated randomly to receive one of 10 doses of doxapram (0.18, 0.23, 0.29, 0.35, 0.41, 0.47, 0.7, 0.93, 1.17 and 1.4 mg.kg-1), one of five doses of pethidine (0.12, 0.18, 0.23, 0.29 and 0.35 mg.kg-1) or saline. Probit analysis demonstrated that the number of patients who stopped shivering with doxapram was independent of the amount of drug given in this dose range. The lowest dose of doxapram (0.18 mg.kg-1) was significantly more effective than placebo (p < 0.01). For pethidine there was a dose-dependent effect on shivering to a maximum of 95% of patients successfully treated with 0.35 mg.kg-1. We conclude that 0.35 mg.kg-1 of pethidine is the minimum dose required to treat post-anaesthetic shivering effectively. We also conclude that 0.18 mg.kg-1 of doxapram is as effective as 1.4 mg.kg-1 in the treatment of post-anaesthetic shivering. Further study is required to find the minimum effective dose of doxapram.

Adolescent↗
PubMed1995

Analgesia after caesarean section. The use of rectal diclofenac as an adjunct to spinal morphine.

A double-blind placebo-controlled study was performed to assess the analgesic effect of rectal sodium diclofenac 100 mg after Caesarean section using subarachnoid hyperbaric bupivacaine 0.5% and morphine 0.2 mg. During the 48 h follow-up period, both placebo and diclofenac groups had comparable analgesia as measured by visual analogue scores (VAS) at rest and on movement. However, diclofenac prolonged the mean time to first analgesia by more than 5 h from 13 h 45 min in the placebo group to 18 h 58 min (p < 0.03). The incidence of side effects (nausea, vomiting, itching, excessive lochia loss and the need for additional analgesia) were comparable in each group.

Adult↗
PubMed1995

A comparison of diclofenac with ketorolac for pain relief after knee arthroscopy.

We performed a double-blind controlled trial to compare the analgesic effect of two nonsteroidal anti-inflammatory drugs. We compared rectal diclofenac 100 mg given 1 h before induction of anaesthesia with intravenous ketorolac 10 mg given immediately before anaesthesia in 40 patients undergoing arthroscopy of the knee as day cases. A visual analogue scale was used to assess pain prior to discharge. Pain, analgesic consumption, sleep disturbance and restriction of activities were recorded by telephone enquiry 24 h after surgery. There was no difference in the pain parameters, sleep disturbance, or restriction of activity between groups. We suggest that ketorolac 10 mg intravenously and diclofenac 100 mg rectally provide comparable postoperative analgesia in the first 24 h after arthroscopy of the knee.

Adolescent↗
PubMed1995

Local anaesthesia for cannulation. Has practice changed?

A questionnaire study was undertaken to assess the influence of recently published, simple and conclusive research on the practice of anaesthetists in four centres. The research had clearly demonstrated the benefit of subcutaneous infiltration of local anaesthetic in reducing the pain of intravenous cannulation. Of the 81% who responded, 71% were aware of the research; 43% of these anaesthetists had altered their clinical practice as a result of the research and 73% used local anaesthesia for cannulae of 18 gauge or less, compared with only 46% of those who were unaware of the research. Practice comparisons were made between centres and grades of anaesthetist. Senior house officers were significantly less likely to be aware of the research than other grades. Anomalies were identified between the apparent awareness of the research and routine practice agreeing with the study findings. The value of research and the incorporation of clinical findings into everyday practice is discussed.

Anesthesia Department, Hospital↗
PubMed1992

Expression of dihydropyridine receptor (Ca2+ channel) and calsequestrin genes in the myocardium of patients with end-stage heart failure.

Cytoplasmic free calcium ions (Ca2+) play a central role in excitation-contraction coupling of cardiac muscle. Abnormal Ca2+ handling has been implicated in systolic and diastolic dysfunction in patients with end-stage heart failure. The current study tests the hypothesis that expression of genes encoding proteins regulating myocardial Ca2+ homeostasis is altered in human heart failure. We analyzed RNA isolated from the left ventricular (LV) myocardium of 30 cardiac transplant recipients with end-stage heart failure (HF) and five organ donors (normal control), using cDNA probes specific for the cardiac dihydropyridine (DHP) receptor (the alpha 1 subunit of the DHP-sensitive Ca2+ channel) and cardiac calsequestrin of sarcoplasmic reticulum (SR). In addition, abundance of DHP binding sites was assessed by ligand binding techniques (n = 6 each for the patients and normal controls). There was no difference in the level of cardiac calsequestrin mRNA between the HF patients and normal controls. In contrast, the level of mRNA encoding the DHP receptor was decreased by 47% (P less than 0.001) in the LV myocardium from the patients with HF compared to the normal controls. The number of DHP binding sites was decreased by 35-48%. As reported previously, expression of the SR Ca(2+)-ATPase mRNA was also diminished by 50% (P less than 0.001) in the HF group. These data suggest that expression of the genes encoding the cardiac DHP receptor and SR Ca(2+)-ATPase is reduced in the LV myocardium from patients with HF. Altered expression of these genes may be related to abnormal Ca2+ handling in the failing myocardium, contributing to LV systolic and diastolic dysfunction in patients with end-stage heart failure.

Adolescent↗