British journal of anaesthesia
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Randomized Controlled Trial Clinical Trial
Partial reversal of the effects of extradural clonidine by oral yohimbine in postoperative patients.
Extradural clonidine produces analgesia, with sedation, hypotension and bradycardia, in postoperative patients. This study assessed if oral yohimbine would reverse these side effects. We studied 30 ASA I-II patients undergoing orthopaedic surgery. ⋯ Pain score was measured on a visual analogue scale (VAS); sedation was assessed on a simple scale graded from 0 (awake and alert) to 3 (deeply sedated, awakening after tactile stimulations) and heart rate and arterial pressure were monitored for 5 h. Yohimbine reversed the sedation induced by extradural clonidine, but also shortened the duration of analgesia (31 (SD 15) min, 186 (72) min and 126 (52) min in the placebo, extradural clonidine and extradural clonidine+yohimbine groups, respectively) (P < 0.05), and did not reduce the hypotension and bradycardia related to clonidine administration. These results suggest that alpha 2 adrenoceptors are mediators of the sedation induced by clonidine and that the haemodynamic effects are not related to stimulation of supraspinal alpha 2 receptors.
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Randomized Controlled Trial Comparative Study Clinical Trial
The pressor response to venous cannulation: attenuation by prior infiltration with local anaesthetic.
We have compared the cardiovascular response to insertion of an 18-gauge venous cannula in 40 healthy patients. In 20 of the patients, cannulation was preceded by infiltration of local anaesthetic. ⋯ We conclude that there is a significant pressor response to venous cannulation which is obtunded by prior infiltration with local anaesthetic. We recommend, therefore, that s.c. injection of lignocaine should be considered before insertion of an i.v. cannula, especially in the high risk patient.
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Randomized Controlled Trial Comparative Study Clinical Trial
IV anaesthesia with propofol using a target-controlled infusion system: comparison with inhalation anaesthesia for general surgical procedures in children.
We studied 40 children undergoing general surgical procedures. They were allocated randomly to receive induction of anaesthesia with propofol 3-5 mg kg-1 followed by maintenance with halothane and an appropriate regional block, or induction and maintenance of anaesthesia with a computerized, target-controlled infusion of propofol with a regional block. ⋯ There were no significant differences between the groups in heart rate, mean arterial pressure and end-expired carbon dioxide concentration during anaesthesia. There was no significant difference in the recovery times of the two groups.
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In order to determine if the Adult Respiratory Distress Syndrome (ARDS) is associated with a shortage of pulmonary surfactant, we have examined a series of 155 undiluted tracheal aspirates obtained from 23 patients with ARDS and from 30 patients without ARDS, all 53 needing ventilatory support. The unfixed and unstained specimens were examined by polarized light microscopy for the presence of pulmonary surfactant. Free surfactant particles were present in the aspirates of 50 patients (95%). ⋯ Fibrinogen/fibrin was found in the aspirates from 20 of 21 patients with ARDS and in only five of 30 patients without ARDS; these five had bronchopneumonia. The method has a sensitivity of 0.95 and a specificity of 0.83. The role of plasma proteins and of neutrophil leucocytes in causing ARDS is discussed.