Anaesthesia
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Randomized Controlled Trial Clinical Trial
Intravenous lignocaine and sympathoadrenal responses to laryngoscopy and intubation. The effect of varying time of injection.
We have studied the effect of varying the timing of a prior dose of intravenous lignocaine 1.5 mg/kg on the cardiovascular and catecholamine responses to tracheal intubation. Forty healthy patients were given an intravenous injection of either placebo or lignocaine 2, 3 or 4 minutes before tracheal intubation. There was a significant increase in heart rate of 21-26% in all groups. There was no significant increase in mean arterial pressure in response to intubation in any group of patients given lignocaine before intubation, but in the placebo group, mean arterial pressure increased by 19.1% compared to baseline values (p less than 0.05).
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Case histories are reported of three patients who had large retrosternal goitres which were responsible for significant abnormalities of the airway. Computerised axial tomography demonstrated the exact anatomy. The site of tracheal compression was shown and accurate measurements of the diameter of the trachea at its narrowest point were made. This information was useful when the management of the patient was planned.
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Randomized Controlled Trial Comparative Study Clinical Trial
Epidural infusion of diamorphine with bupivacaine in labour. A comparison with fentanyl and bupivacaine.
We have compared the analgesic effects of three epidural infusions in a randomised, double-blind study of 61 mothers in labour. An initial dose of bupivacaine 0.5% 8 ml was followed by either bupivacaine 0.125%, bupivacaine 0.125% with diamorphine 0.0025% or bupivacaine 0.125% with fentanyl 0.0002%. ⋯ Diamorphine was shown to be the more effective supplement to bupivacaine. The 5% incidence of pruritus in the opioid groups was less than that reported by earlier authors.
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Review Comparative Study
Potential errors in pulse oximetry. I. Pulse oximeter evaluation.
There is no absolute reference for oxygen saturation, although multiwavelength in vitro oximeters are accepted as the 'gold standard'. Regardless of whether fractional or functional saturation is used by manufacturers to calibrate their oximeters, evaluation against fractional saturation is recommended since this is the clinically relevant variable. The use of standard notation and comparisons based on bias and precision is recommended. ⋯ The empirical algorithms used to convert the signal to its 'readout value' and the quality control of hardware may both be important sources of variability between oximeters. Change in blood temperature may introduce errors in pulse oximeter and in vitro oximeter saturation readings, but these will be clinically insignificant. Changes in blood pH should not decrease pulse oximetry accuracy.
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Randomized Controlled Trial Clinical Trial
The alkalinisation of bupivacaine for intercostal nerve blockade.
A double-blind randomised study was performed to investigate the effect of pH adjustment of bupivacaine, with adrenaline 1:200,000, on the duration of block and pain relief after intercostal nerve blockade following thoracotomy. One group (n = 10) received bupivacaine with adrenaline 1:200,000 (pH = 4.1) and the other (n = 10) received alkalinised bupivacaine with adrenaline 1:200,000 (pH = 6.9). ⋯ A progressive regression of block, not previously described, was observed, explicable by means of spread of local anaesthesia to adjacent intercostal nerves. Alkalinisation of bupivacaine with adrenaline for intercostal nerve blockade has little clinical benefit.