British journal of anaesthesia
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Comparative Study
An alternative method of increasing PCO2 using apnoea and continuous positive airway pressure.
We have examined the use of continuous positive airway pressure (CPAP) and apnoeic oxygenation for restoration of spontaneous breathing at the end of anaesthesia after controlled ventilation. We studied 45 adult patients without a history of acute or chronic respiratory disturbances. Anaesthesia was induced with thiopentone or propofol and maintained with nitrous oxide and enflurane in oxygen. ⋯ All patients were well oxygenated (PO2 mean 43.5 kPa, range 21-76 kPa) when spontaneous ventilation started. The pH was close to 7.28 in most cases (mean 7.28, range 7.21-7.32), and PCO2 varied in the range 6.6-9.9 kPa (mean 7.9 kPa). It is concluded that the method is safe with regard to oxygenation and acid-base balance.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of the effect of EMLA cream, subcutaneous ring anaesthesia and a double cuff technique in the prevention of tourniquet pain.
We have examined the effect of EMLA on tourniquet pain and compared it with those of subcutaneous ring anaesthesia (SRA), a double cuff technique and a single cuff (control) during i.v. regional anaesthesia. The durations of analgesia (mean 57.3 (SD 16.6) min) and tolerance (72.3 (13.9) min) to tourniquet inflation in the EMLA group were comparable to those in the SRA group (54.1 (16.2) min and 68.3 (19.0) min), but significantly (P < 0.05) greater than those in the control group (30.0 (10.7) min and 45.6 (14.0) min). The double cuff technique was the most effective method, with 91.5 (14.9) min duration of analgesia. We conclude that EMLA provided a significant analgesic effect on tourniquet pain compared with the control group, but a relatively limited analgesic effect compared with a double cuff technique.
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Randomized Controlled Trial Clinical Trial
Comparison of nasal cannulae with face mask for oxygen administration to postoperative patients.
Thirty postoperative patients were allocated randomly to receive oxygen by Hudson face mask at 4 litre min-1 (group I) or 2 litre min-1 (group II) via nasal cannulae. From 22:00 on the first night after operation, the position of the nasal cannula or face mask was observed for 8 h using video and oxyhaemoglobin saturation (SpO2) recorded simultaneously. In group I the mask remained on and positioned correctly in five patients. ⋯ In group II the nasal cannula was removed once in one patient for 16 min 38 s and eight times in another for a total of 1 h 18 min 7 s. Average SpO2 with mask on was 98% (range 96.1-99.9%), with mask off 95% (range 89.8-98.8%) and with cannula 97% (range 90.8-99.3%). We conclude that nasal cannulae are more likely to remain in position than face masks and maintain an adequate saturation in most patients.
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We have examined the prolongation of a maintenance dose of vecuronium after an intubating dose of pipecuronium in 45 patients who received either pipecuronium 70 micrograms kg-1 or vecuronium 200 micrograms kg-1 i.v. for tracheal intubation, followed by either pipecuronium 10 micrograms kg-1 or vecuronium 15 micrograms kg-1 for maintenance of neuromuscular block. The duration of the vecuronium maintenance dose was greater after pipecuronium (40 (SD 12) min) than after vecuronium (29 (9) min) (P = 0.02). The duration of pipecuronium after pipecuronium (49 (15) min) was similar to that of vecuronium after pipecuronium. We conclude that the duration of action of vecuronium is prolonged by prior administration of pipecuronium.