Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Oct 1986
Randomized Controlled Trial Clinical TrialAnaesthetic temperature and shivering in epidural anaesthesia.
The mechanism of shivering during epidural analgesia remains unclear. This study investigates the role of the temperature of the local anaesthetic injected extradurally. Forty patients admitted for elective caesarean section under epidural anaesthesia were studied; 20 were given bupivacaine warmed to 37 degrees C (warm group) and 20 were given bupivacaine stored at 4 degrees C (cold group); the occurrence of shivering in both groups was recorded. ⋯ This difference was statistically significant (P less than 0.03). The results suggest that there are thermosensory mechanisms in the human spinal canal. In our view, epidural anaesthetic solutions should be warmed to body temperature prior to injection to reduce the incidence of shivering.
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Acta Anaesthesiol Scand · Oct 1986
Comparative StudyFresh gas flow in coaxial Mapleson A and D circuits during spontaneous breathing.
In a lung model simulating spontaneously breathing halothane anaesthesia, the rebreathing characteristics of the coaxial Mapleson A (Lack circuit) and D (Bain circuit) systems were tested. Using decreasing fresh gas flows (VF), the end-tidal carbon dioxide fraction (FACO2) was monitored and the point of rebreathing (R. P.) detected. ⋯ In neither system did any changes in VCO2 affect the rebreathing characteristics. The conclusion was drawn that the Lack system is a much better choice concerning the fresh gas flows for anaesthesia with spontaneous breathing than the Bain system. It was also concluded that the fresh gas flows recommended by Humphrey for the Lack system (i.e. 51 ml X min-1 X kg b.w.-1) and by the manufacturers for the Bain system (i.e. 100 ml X min-1 X kg b.w.-1) are inadequate and should be increased if a considerable degree of rebreathing is to be avoided.
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Acta Anaesthesiol Scand · Aug 1986
Pulmonary ventilation, CO2 response and inspiratory drive in spontaneously breathing young infants during halothane anaesthesia.
Pulmonary ventilation, CO2 response and inspiratory drive were studied during halothane anaesthesia prior to surgery in 13 spontaneously breathing infants less than 6 months of age. Pneumotachography and capnography were used. Airway and oesophageal pressures were measured and occlusion tests were performed at functional residual capacity. ⋯ It is concluded that young spontaneously breathing infants anaesthetized with halothane (MAC 1.3) have an increased respiratory drive with greater tidal volumes during CO2 stimulations. Respiratory timing, dynamic compliance and total pulmonary resistance were, however, uninfluenced by 4% CO2 stimulation. Increased monitoring of CO2 output in anaesthetized infants is suggested.
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Acta Anaesthesiol Scand · Aug 1986
Randomized Controlled Trial Comparative Study Clinical TrialComparison of different methods of postoperative analgesia after thoracotomy.
Fifty-one patients scheduled for thoracotomy were included in a study involving five different methods of postoperative analgesia. Forty patients were randomly divided into: Group C, receiving intramuscular oxycodone on request following an intraoperative intercostal block; Group IC, intercostal blocks with 0.5% bupivacaine performed prior to surgery, 6 h later and on the first postoperative morning: Group EB, epidural bupivacaine as a continuous infusion of 0.25% bupivacaine (5 ml h-1); Group EM4 epidural morphine 4 mg injected prior to surgery and on the first postoperative morning. In addition, a fifth group (Group EM6) of 11 patients received 6 mg of epidural morphine timed as in Group EM4, but these patients were automatically scheduled to be observed in the ICU. ⋯ Postoperative blood-gas analyses contained slightly elevated PCO2 values (6.0-7.3 kPa) in all groups. Postoperatively, only Group EB was devoid of PCO2 values above 7.3 kPa. Urinary retention was a common complication in the patients receiving epidural analgesia, occurring most frequently in Group EM6; 10 of the 11 patients had to be catheterized.
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Acta Anaesthesiol Scand · Aug 1986
Comparative StudyCO2 production and breathing pattern during invasive and non-invasive respiratory monitoring.
A computerized non-invasive strain gauge system for respiratory monitoring is described and compared with pneumotachography. With the use of simultaneous capnography, changes in breathing pattern, end-tidal PCO2 and CO2 production were evaluated during non-invasive (NIM) and invasive breathing monitoring (IM) in 14 healthy subjects. ⋯ These changes were mainly accomplished by an increased respiratory drive with the timing component unaltered. During IM both end-tidal PCO2 and CO2 production increased significantly as compared with those during NIM.