British journal of anaesthesia
-
Randomized Controlled Trial Comparative Study Clinical Trial
Cricoid pressure applied after placement of the laryngeal mask prevents gastric insufflation but inhibits ventilation.
We studied 50 patients, in a blind, crossover study, to assess if cricoid pressure applied after placement of the laryngeal mask prevented gastric insufflation without affecting ventilation. After induction of anaesthesia and neuromuscular block, a laryngeal mask was inserted and confirmed to be placed correctly. The lungs were ventilated with a maximum inflation pressure of 15 cm H2O. ⋯ In no patient was the mask dislodged after these procedures. Thus, although cricoid pressure applied after insertion of the laryngeal mask prevented gastric insufflation, it also decreased ventilation. The inhibitory effect of cricoid pressure on ventilation without support of the neck was greater than cricoid pressure with support of the neck.
-
Clinical Trial
Continuous extrapleural paravertebral infusion of bupivacaine for post-thoracotomy analgesia in young infants.
We have studied the efficacy of a continuous paravertebral infusion of bupivacaine for the management of post-thoracotomy pain in 20 infants with a median age of 5.3 weeks (range 2 days to 20 weeks). Immediately before chest closure, 0.25% bupivacaine 1.25 mg kg-1 was injected into an extrapleural paravertebral catheter, inserted under direct vision. A continuous infusion of 0.25% bupivacaine 0.5 mg kg-1 h-1 was commenced 1 h later and terminated after 24 h. ⋯ The technique provided effective postoperative pain relief in 18 (90%) patients and the failure in two (10%) infants was attributed to catheter block. Mean maximum serum concentrations of bupivacaine after the loading dose and during infusion were 1.03 (SD 0.56) and 2.00 (0.63) microgram ml-1, respectively. There were no major complications relating to the technique and we conclude that extrapleural paravertebral block is a simple and effective method for post-thoracotomy analgesia in young infants.
-
Randomized Controlled Trial Clinical Trial
Haemostatic changes caused by i.v. regional anaesthesia with lignocaine.
The various components of i.v. regional anaesthesia (IVRA), that is ischaemia, tourniquet compression and the presence of high concentrations of local anaesthetics in the blood vessels of the extremity, may affect haemostatic mechanisms. We performed a cross-over study in 10 healthy male volunteers to examine the role of lignocaine in IVRA on several haemostatic variables, and those indicating fibrinolysis and platelet function in particular. Venous blood samples were obtained from the test arm and the opposite arm before IVRA, at the time of tourniquet cuff deflation and 30 min thereafter. ⋯ Although IVRA appeared to induce some platelet dysfunction, there was a small increase in TEG amplitude indicative of improved fibrin-platelet interaction in the lignocaine-exposed arm at the time of cuff deflation. We conclude that the presence of high i.v. lignocaine concentrations (median 144.4 micrograms ml-1 in cubital veins at the end of the tourniquet time) potentiated ischaemia-induced fibrinolysis activation during IVRA. Concomitant platelet dysfunction was not aggravated by lignocaine.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Combination of ondansetron and dexamethasone in the prophylaxis of postoperative nausea and vomiting.
We studied 100 ASA I-II females undergoing general anaesthesia for major gynaecological surgery, in a prospective, double-blind, placebo-controlled, randomized study. Patients received one of four regimens for the prevention of postoperative nausea and vomiting (PONV): ondansetron 4 mg (n = 25), dexamethasone 8 mg (n = 25), ondansetron with dexamethasone (4 mg and 8 mg, respectively, n = 25) or placebo (saline, n = 25) There were no differences in background factors or factors related to operation and anaesthesia, morphine consumption, pain or side effects between groups. The incidence of nausea and emetic episodes in the ondansetron with dexamethasone group was lower than in the placebo (P < 0.01), ondansetron (P < 0.05) and dexamethasone (P = 0.057) groups. ⋯ Dexamethasone appeared to be preferable in preventing nausea than emetic episodes. Fewer patients in the ondansetron with dexamethasone group needed antimetic rescue (P < 0.01 vs placebo and P < 0.05 vs ondansetron). We conclude that prophylactic administration of combined ondansetron and dexamethasone is effective in preventing PONV.