British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of hypertonic saline (5%), isotonic saline and Ringer's lactate solutions for fluid preloading before lumbar extradural anaesthesia.
We have compared the haemodynamic effects of fluid preloading performed before lumbar extradural anaesthesia with isotonic saline (NS), 5% hypertonic saline (HS) and Ringer's lactate (RL) solutions in 30 ASA I patients undergoing minor orthopaedic surgery, allocated randomly to the three groups. All patients received an equal amount of sodium (2 mmol kg-1). After fluid preloading, lumber extradural anaesthesia was performed (2% lignocaine 6 mg kg-1) and ephedrine was administered in order to maintain mean arterial pressure (MAP) > 80% of its control value. ⋯ MAP was not affected by any fluid preload and its maximal decrease after lumbar extradural anaesthesia was similar in all groups. Infusion of 5% HS 2.3 ml kg-1 was tolerated well and produced a significant (P < 0.05) but moderate hypernatraemia lasting 90 min after the end of fluid preloading. We conclude that HS may be useful when rapid fluid preloading is desired, in situations where excess free water administration is not desired.
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Randomized Controlled Trial Clinical Trial
Cricoid pressure may prevent insertion of the laryngeal mask airway.
We have studied 42 female patients undergoing elective day-case surgery allocated randomly to two groups. After induction of anaesthesia an attempt was made to insert a laryngeal mask airway after application of cricoid pressure in one group or with no cricoid pressure in the other. ⋯ The laryngeal mask airway was then inserted successfully in all 17 patients after removal of cricoid pressure. The implications of having to remove cricoid pressure if a laryngeal mask airway is to be inserted are discussed.
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Randomized Controlled Trial Comparative Study Clinical Trial
Onset and recovery of rocuronium (Org 9426) and vecuronium under enflurane anaesthesia.
We have studied the onset, duration of action and recovery index of twice the ED90 of rocuronium (Org 9426) (0.6 mg kg-1) and of vecuronium (0.08 mg kg-1) in patients during enflurane anaesthesia. Rocuronium had a significantly shorter mean onset time of 1.8 (SD 0.4) min, compared with vecuronium 3.4 (0.8) min. Clinical duration (time for the first twitch in the train-of-four to recover to 25% of control) was similar for both drugs (29 (10) min vs 31 (12) min). Spontaneous recovery times (TOF ratio 70%) did not differ significantly between rocuronium (47 (10) min) and vecuronium (44 (11) min).
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Randomized Controlled Trial Comparative Study Clinical Trial
Mechanism of extension of spinal anaesthesia by extradural injection of local anaesthetic.
We have examined the effect of extradual injection of 0.5% bupivacaine or normal saline on the progression of spinal anaesthesia in 28 patients undergoing Caesearean section. Three groups were studied. Subarachnoid anaesthesia was established in all patients. ⋯ Sensory levels were compared at 5-min intervals and extension of the block was found to be similar in groups B and C and significantly faster than the control (P < 0.05). The quality of anaesthesia and incidence of adverse effects was similar for all three groups. We conclude that the mechanism of extension of spinal anaesthesia by extradural injection of local anaesthesia is largely a volume effect.