Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Randomized Controlled Trial Clinical Trial
Patient-controlled epidural analgesia in labour: varying bolus dose and lockout interval.
This double-blind prospective study was designed to determine the best dose variables for patient-controlled epidural analgesia (PCEA) and to compare bolus-only PCEA with continuous infusion epidural analgesia (CIEA) during the first stage of labour. Five groups of parturients self-administered 0.125% bupivacaine with 1:400,000 epinephrine and fentanyl 2.5 micrograms.ml-1 using PCA pumps programmed as follows: Group A, 2 ml bolus/10 min lockout interval (LI); Group B, 3 ml bolus/15 min LI; Group C, 4 ml bolus/20 min LI; Group D, 6 ml bolus/30 min LI; Group E, 8 ml.hr-1 continuous infusion. Hourly assessments included: VAS scores for pain and satisfaction, sensory and motor block, bupivacaine and fentanyl consumption. ⋯ There was higher consumption of bupivacaine and fentanyl in Group E than in any of the other four groups: bupivacaine mg.hr-1, mean (SD), 9.4 (2.7) in Group E vs 5.2 (1.7) in Groups A-D inclusive (P < 0.0001); fentanyl microgram.hr-1, 19.6 (4.6) in group E vs 12.6 (7.5) in Groups A-D inclusive (P < 0.05). Motor block was minimal, whereas sensory levels were higher at the 3- and 4-hour assessments in Groups D and E than in all other groups (P < 0.05). Plasma fentanyl concentrations were < 0.5 ng.ml-1 in all samples and no sequelae from fentanyl were observed, apart from mild pruritus.(ABSTRACT TRUNCATED AT 250 WORDS)
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Laryngoscope blade design has tended to be relatively arbitrary and so far scientific analysis has not allowed useful comparisons between blade shapes. A new theoretical method of analysing laryngoscope blades is introduced and uses the depth of insertion profiles of two angular measurements. One represents eyeline displacement and the other the forward space that the blade occupies at the level of the mandible. ⋯ All three are superior to the straight Soper size 3 blade. The Macintosh size 1 and 2 blades are quite different from the larger Macintosh blades. This theoretical basis for blade analysis is consistent with commonly expressed clinical opinions and may influence blade design in the future.
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Case Reports
Delayed ischaemia of the hand necessitating amputation after radial artery cannulation.
We present a case of ischaemic hand injury in a patient, who had 95% occlusion of both the ulnar and radial arteries, after atraumatic placement of a left radial artery catheter. The presence of cigarette burns on the dorsum of the hand was highly suggestive of vascular compromise. ⋯ Ten days after placement the patient complained of pain with ensuing ischaemic changes resulting in necrosis of the finger tips and eventual amputation of the hand. We recommend using other sites of arterial access such as axillary or superficial temporal artery in patients with severe peripheral vascular disease.
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Randomized Controlled Trial Clinical Trial
Intubating conditions and haemodynamic changes following thiopentone or propofol for early tracheal intubation.
Intubating conditions and haemodynamic changes were studied 30 sec after a fixed induction dose of thiopentone or propofol in patients scheduled for elective surgery. The hypnotic agent was preceded by the administration of papaveretum 10 mg three minutes before induction and alcuronium 0.2 mg.kg-1 at induction. Ease of intubation was graded and the study conducted in a randomised double-blind fashion. ⋯ In the propofol group there was a decrease in systolic pressure after induction (average 14.4%; range 15.5% increase to 41.4% decrease, P < 0.05) but the subsequent pressor response to intubation was markedly attenuated compared with baseline (average systolic pressure decreased 15.5% (range 22.4% increase to 42.7% decrease)). Following intubation and maintenance, ventilation with nitrous oxide 70% and halothane 1% the systolic pressure decreased markedly in both groups with a greater reduction in the propofol group (P < 0.05). Compared with baseline there were increases (P < 0.0001) in heart rate in both groups from induction of anaesthesia to the end of study.(ABSTRACT TRUNCATED AT 250 WORDS)
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Displacement of the larynx by backward, upward and rightward pressure on the thyroid cartilage or "BURP" may improve visualization of the glottis in some cases of difficult direct laryngoscopy. In a patient with the Treacher-Collins syndrome in whom conventional laryngoscopy had proved impossible and tracheal intubation extremely difficult, this manoeuvre exposed the entire glottis and made tracheal intubation under direct vision easy. In a patient with protruding upper incisors and a prominent premaxilla which precluded a view of the glottis by conventional laryngoscopy, "BURP" again revealed the glottic opening and simplified the placement of an endotracheal tube. This experience suggests that "BURP" be considered as a potential aid in the management of difficult direct laryngoscopy.