British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Re-evaluation of appropriate size of the laryngeal mask airway.
We have assessed 32 males and 31 females in a randomized, crossover study to see if there was any difference in the correct positioning of the laryngeal mask, optimal ventilation (defined as no gas leak around the mask at an airway pressure of 18 cm H2O) and cuff visibility between sizes 4 and 5 masks in males and sizes 3 and 4 in females. The position of the mask in relation to the glottis was assessed using a fibreoptic bronchoscope. ⋯ Gas leak was significantly less frequent for a larger than a smaller mask (P < 0.01 for both sexes), whereas the cuff was more often seen in the mouth with larger masks (P < 0.02 for males and P < 0.01 for females). Therefore, larger masks (size 4 in females and size 5 in males) provided a better seal than smaller sizes without worsening the relative position of the mask to the glottis; however, the larger mask came up within the mouth more often, which could interfere with tonsillectomy and could increase the risk of sore throat or lingual nerve damage.
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Randomized Controlled Trial Clinical Trial
Comparison of pentastarch and Hartmann's solution for volume preloading in spinal anaesthesia for elective caesarean section.
We studied 160 patients undergoing elective Caesarean section under spinal anaesthesia who received a preloading volume of 15 ml kg-1 of 10% pentastarch in 0.9% saline, or Hartmann's solution, in a prospective, randomized, double-blind study. We compared the incidence of spinal-induced hypotension in each group. Hypotension was defined as a decrease in systolic arterial pressure to less than 70% of baseline values or < or = 90 mm Hg, whichever was the greater. ⋯ Linear regression analysis showed that the only significant variable was type of fluid used. Blood glucose concentrations were not related to the presence of hypotension. We conclude that starches may be suitable for preloading in Caesarean section under spinal anaesthesia and provide an alternative to the aggressive use of vasoconstrictors.
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Randomized Controlled Trial Clinical Trial
Postoperative analgesia with i.v. patient-controlled morphine: effect of adding ketamine.
We have studied the effect of adding ketamine to i.v. morphine patient-controlled analgesia (PCA) for the treatment of pain after laparotomy. Thirty patients were allocated randomly to receive PCA with saline or ketamine in a double-blind, randomized study. Analgesia was started in the recovery room when visual analogue scale (VAS) scores were > 4. ⋯ VAS scores decreased significantly with time (P = 0.0001) and were similar (P = 0.3083) in both groups. Cumulative morphine consumption at 48 h was significantly lower in the ketamine group (28 mg) than in the control group (54 mg) (P = 0.0003). Nausea was less frequent in the ketamine group (P = 0.03).
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Randomized Controlled Trial Comparative Study Clinical Trial
Double-blind comparison of sevofluran vs propofol and succinylcholine for tracheal intubation in children.
We have studied intubating conditions in 64 healthy children, aged 3-10 yr, undergoing adenotonsillectomy, in a double-blind, randomized study. Intubation was performed 150 s after induction using either 8% sevoflurane in nitrous oxide and oxygen or propofol 3-4 mg kg-1 with succinylcholine 2 mg kg-1. ⋯ The sevoflurane technique cost 3.62 +/- 0.55 Pounds to completion of tracheal intubation, significantly more (P < 0.001) than the cost of propofol-succinylcholine and isoflurane (2.04 +/- 0.54 Pounds) when based on actual amount of drug used. This cost increased to 4.38 +/- 0.05 Pounds when based on whole ampoules, which is significantly more than the cost of sevoflurane (P < 0.001).
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Randomized Controlled Trial Clinical Trial
A potential mechanism of propofol-induced pain on injection based on studies using nafamostat mesilate.
To elucidate the mechanism of propofol-induced pain on injection, we performed several studies using nafamostat mesilate, a kallikrein inhibitor, or lidocaine. As both pretreatment and low-dose mixing with nafamostat produced the same effects on pain reduction, we used the latter method in the following experiments. Low-dose mixing had the same effect on injection pain as mixing with lidocaine. ⋯ Injection of the lipid solvent before propofol significantly aggravated pain compared with prior injection of saline, although the lipid solvent injected twice caused no change in pain. These results suggest that the lipid solvent for propofol activates the plasma kallikrein-kinin system and produces bradykinin which modifies the injected local vein. This modification of the peripheral vein may increase the contact between the aqueous phase propofol and the free nerve endings of the vessel, resulting in aggravation of propofol-induced pain.