Biomedical subjects
D Chamley
Publications and source records attributed to D Chamley.
Malignant hyperthermia in infancy and identification of novel RYR1 mutation.
Malignant hyperthermia (MH) has been reported as non-existent in children less than 1 yr old, although several unconfirmed reports have been published. A case report of MH in a 6-month-old child is presented, with confirmation of MH susceptibility by in vitro contracture testing of quadriceps muscle at 13 yr old. Genetic analysis revealed a novel RYR1 mutation that substitutes arginine 2452 for tryptophan in a region of the calcium channel mutated in several other MH pedigrees.
A comparison of 0.5% ropivacaine and 0.5% bupivacaine for axillary brachial plexus anaesthesia.
The purpose of this study was to compare the use of 0.5% ropivacaine with 0.5% bupivacaine for axillary brachial plexus anaesthesia. Sixty-six patients undergoing upper limb surgery were enrolled in a double-blind, randomized, multicentre trial. Five patients were subsequently excluded for various reasons. Of the remaining patients, 30 received 40 ml of 0.5% ropivacaine and 31 received 40 ml of 0.5% bupivacaine. Brachial plexus block was performed by the axillary approach using a standardized technique with a peripheral nerve stimulator. Parameters investigated included the frequency, onset and duration of sensory and motor block, the quality of anaesthesia and the occurrence of any adverse events. The six principal nerves of the brachial plexus were studied individually. The frequency for achieving anaesthesia per nerve ranged from 70 to 90% in the ropivacaine group and 81 to 87% in the bupivacaine group. The median onset time for anaesthesia was 10 to 20 minutes with ropivacaine and 10 to 30 minutes with bupivacaine, and the median duration was 5.3 to 8.7h with ropivacaine and 6.9 to 20.3h with bupivacaine. Motor block was evaluated at the elbow, wrist and hand, and was completely achieved at a rate of 60 to 73% in the ropivacaine group and 55 to 71% in the bupivacaine group. The median duration of motor block was 6.5 to 7.5h with ropivacaine and 6.0 to 9.0h with bupivacaine. These parameters were not statistically different. The duration of partial motor block at the wrist (6.8 v 16.4h) and hand (6.7 v 12.3h) was significantly longer with bupivacaine. Ropivacaine 0.5% and bupivacaine 0.5% appeared equally efficacious as long-acting local anaesthetics for axillary brachial plexus block.
Continuous extradural infusion of ropivacaine for prevention of postoperative pain after major orthopaedic surgery.
We studied 151 patients undergoing total hip or knee arthroplasty, or cruciate ligament reconstruction in a multicentre study in Australia and New Zealand. Patients were openly allocated randomly to one of five treatment groups or to a control group. General anaesthesia was induced after introduction of extradural block with 0.5% ropivacaine. After surgery, patients received an extradural infusion of 0.2% ropivacaine at 6, 8, 10, 12 or 14 ml h-1 or received no postoperative extradural infusion (control group). All patients had access to i.v. PCA morphine for supplementary analgesia. Morphine consumption was lower in all treatment groups compared with the control group, decreasing with increasing ropivacaine infusion rate. Median VAS scores were lower in all ropivacaine infusion groups compared with the control group for the first 10 h of the study; however by the end of the study, VAS scores were similar in all groups. The higher ropivacaine infusion rates caused a slower convergence of spread of the initial sensory block and a higher degree of motor block. The overall incidence of side effects was similar, with the exception of a higher incidence of urinary retention and hypotension in the groups receiving the higher rates of ropivacaine. The quality of treatment scores were similar for all treatment groups (Br. J. Anaesth. 1996; 76: 606-610).
An assessment of postoperative oxygen therapy in patients with fractured neck of femur.
Arterial oxygen tension was studied in sixty patients with fractured neck of femur. The mean preoperative arterial oxygen tension was 63.7 mmHg (SD 12.8). Half of the patients received nasal oxygen for five days postoperatively. In these patients, mean arterial oxygen tension was greater at all times than preoperative values, and exceeded values in those not receiving oxygen in whom no change in oxygen tension occurred until an increase on the fifth postoperative day.
Wall outlet oxygen failure.
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