Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Dec 1984
Midazolam as adjunct to high-dose fentanyl anaesthesia for coronary artery bypass grafting operation.
The usefulness of midazolam as an adjunct during high-dose fentanyl anaesthesia was studied by following the changes in the haemodynamics and total body oxygenation after an intravenous injection of 0.075 mg/kg and 0.15 mg/kg of midazolam during the induction of fentanyl (75 micrograms/kg)-oxygen anaesthesia for a coronary artery bypass operation. These responses were then compared to the changes seen in patients receiving the same fentanyl anaesthesia without the midazolam. A rapid decline after the midazolam injection was seen in the mean systemic arterial pressure (24-32%--the lowest individual value was 45 mmHg (6.0 kPa)) and in the systolic and diastolic pulmonary arterial pressures (29-33% and 30-31%) in 1-3 min. ⋯ The tissue oxygenation seemed to be sufficient in all groups during the study period. An intravenous injection of a relatively low dose of midazolam during the induction of high-dose fentanyl anaesthesia seems to be followed by rapidly increased venous pooling and a moderately to severely decreased systemic arterial pressure. Based on the results of this study, midazolam cannot be recommended as an adjunct during high-dose fentanyl anaesthesia.
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Acta Anaesthesiol Scand · Dec 1984
Distribution of expiratory gas and rebreathing in a T-piece modification combined with a PEEP valve.
T-piece modifications with PEEP valves are often used in weaning from mechanical ventilation or for intubated patients not requiring ventilatory support. Distribution of expiratory gas and the extent of rebreathing in a T-piece modified with an inspiratory reservoir (ICR) and with a PEEP valve were studied in a model with various fresh gas flows (FGF), tidal volumes and frequencies at three valve settings: 0 cmH2O (ZEEP) and PEEP of 5 and 10 cmH2O (0.490-0.981 kPa). Two types of distribution of expiratory gas were delineated: type one with expiratory gas in the inspiratory limb (IL) and a high ratio of the maximum CO2 content and corresponding end-expiratory CO2 concentration in the expiratory limb (EL) (FmaxCO2/FECO2) and a type 2 with no detectable alveolar gas in the IL and a low ratio of FmaxCO2/FECO2. ⋯ The ratio of FGF to minute ventilation just preventing rebreathing during spontaneous ventilation is approximately 1, in contrast to 3 in other modifications. These advantages minimize the risk of rebreathing, even when the minute ventilation rises to that of the fresh gas flow. The T-system with a compliant inspiratory reservoir and a PEEP valve can, in most clinical weaning situations, satisfy the inspiratory peak flow of different respiratory patterns with a standard FGF of 15 l X min-1.
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Acta Anaesthesiol Scand · Dec 1984
Randomized Controlled Trial Comparative Study Clinical TrialComparison of intramuscular analgesia, intercostal block, epidural morphine and on-demand-i.v.-fentanyl in the control of pain after upper abdominal surgery.
Eighty patients undergoing upper abdominal surgery were randomly allocated to four groups according to the postoperative pain treatment. All patients had a standardized balanced anaesthesia and for postoperative analgesia either intramuscular oxycodone and/or metamizol (IM), intercostal block with 0.5% bupivacaine (IC), epidurally 4 mg morphine (EM) or i.v. infusion of fentanyl 0.54-0.99 micrograms min-1 + on-demand boluses of 7.2-13.5 micrograms (ODAC) were given. The pain intensity 2 h postoperatively was similar in all groups, mean score ranging from 3.2-4.3 on a scale from 0-10. ⋯ The amount of fentanyl infused in 24 h to the ODAC patients varied considerably, 814-2233 micrograms, as did the number of on-demand boluses, 3-155. At 24 h, an efficacy rating "good" was distributed as follows: IM 9/20, IC 11/20, EM 11/20 and ODAC 13/20. In the whole patient material 92.5% rated their condition as "good" or "fair".
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Acta Anaesthesiol Scand · Dec 1984
Comparative StudyHydroxyethyl starches, dextran and balanced salt solution in correction of hypotension during epidural anaesthesia.
A low molecular weight (Mw 38 000) and a medium molecular weight (Mw 125 000) hydroxyethyl starch and a medium molecular weight dextran (Mw 70 000) solution were compared with a balanced salt solution in 123 patients undergoing operations of the lower extremities in epidural anaesthesia; 500 ml of the studied solutions were infused during 15 min after the injection of the epidural anaesthetic. The need for etilefrine hydrochloride as a vasoconstrictor in correcting hypotensive reactions was recorded. Changes in haemoglobin (Hb), haematocrit (Hct), serum total protein and serum albumin concentrations were measured. ⋯ The fall in blood pressure cannot be totally inhibited by administration of 500 ml plasma substitute. According to the differences in Hb, Hct, serum protein and albumin values, the hydroxyethyl starch solutions were significantly more effective plasma substitutes than the balanced salt solution and as effective as dextran. No side-effects attributable to the solutions used were observed.
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Acta Anaesthesiol Scand · Dec 1984
Randomized Controlled Trial Comparative Study Clinical TrialPerivascular axillary block V: blockade following 60 ml of mepivacaine 1% injected as a bolus or as 30 + 30 ml with a 20-min interval.
Perivascular axillary blockade was performed on 60 patients with the aid of a catheter technique. The patients were randomly allocated to two groups. All patients received the same dose of local anaesthetic: 60 ml of mepivacaine 1% with adrenaline, but one group received the dose as a bolus injection, whereas the other group received the dose as fractional injections of 30 + 30 ml with an interval of 20 min. ⋯ There was no difference in blood concentrations of mepivacaine between the two groups. None of the 60 patients showed any sign of systemic toxic reactions. Fractional injection of local anaesthetic in perivascular axillary blockade does not offer any advantage over bolus injection with regard to the resulting blockade.