Acta anaesthesiologica Scandinavica
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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
Comparative StudyThe effects of d-tubocurarine, pancuronium and atracurium on the responses of gastrocnemius and soleus muscles in the cat.
In vivo, the effects of d-tubocurarine (0.20 mg kg-1), pancuronium (0.015 mg kg-1) and atracurium (0.15 mg kg-1) on the responses of the indirectly stimulated cat gastrocnemius (fast) and soleus (slow) muscles to a twitch, train-of-four and tetanic stimuli were studied. The soleus muscle demonstrated a greater degree of fade than the gastrocnemius in response to tetanic stimuli (50 Hz). ⋯ Recovery of train-of-four ratio occurred more rapidly than did the tetanic fade ratio. At a time when train-of-four ratio exceeded 0.7, tetanic fade was still evident, especially in the soleus muscle.
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Acta Anaesthesiol Scand · Dec 1984
Comparative StudyRectal diazepam compared to intramuscular pethidine/promethazine/chlorpromazine with regard to gastric contents in paediatric anaesthesia.
Sixty children, aged 1-12 years, were investigated with regard to gastric pH and volume before general anaesthesia. Thirty children (group D) received diazepam 0.75 mg/kg b.w. rectally 1 h before anaesthesia. Thirty children (group L) received a "lytic cocktail" (pethidine 28 mg, promethazine 7 mg, chlorpromazine 7 mg per ml) 0.05 ml/kg b.w. intramuscularly 1 h before anaesthesia. ⋯ The number of children in group L with gastric juice volume exceeding 0.4 ml/kg and the number of children with pH less than 2.5 was significantly smaller compared to group D. The number of children with both gastric pH less than 2.5 and gastric juice volume greater than 0.4 ml/kg was significantly smaller in the group receiving "lytic cocktail" intramuscularly compared to the group receiving diazepam rectally. Bile-stained gastric contents was not related to the gastric pH.
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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.