British journal of anaesthesia
-
Randomized Controlled Trial Clinical Trial
S(+)-ketamine for caudal block in paediatric anaesthesia.
We have evaluated the intra- and postoperative analgesic efficacy of preservative-free S(+)-ketamine compared with bupivacaine for caudal block in paediatric hernia repair. After induction of general anaesthesia, 49 children undergoing hernia repair were given a caudal injection (0.75 ml kg-1) of S(+)-ketamine 0.5 mg kg-1 (group K1), S(+)-ketamine 1.0 mg kg-1 (group K2) or 0.25% bupivacaine with epinephrine 1:200,000 (group B). No additional analgesic drugs were required during operation in any of the groups. ⋯ Groups B and K2 required less analgesics in the postoperative period compared with group K1 (30% and 33% vs 72%; P < 0.05). Postoperative sedation scores were comparable between the three groups. We conclude that S(+)-ketamine 1.0 mg kg-1 for caudal block in children produced surgical and postoperative analgesia equivalent to that of bupivacaine.
-
Randomized Controlled Trial Clinical Trial
Oral preanaesthetic medication for children: double-blind randomized study of a combination of midazolam and ketamine vs midazolam or ketamine alone.
Anxiolysis and sedation with oral midazolam are common practice in paediatric anaesthesia. However, good or excellent results are seen in only 50-80% of cases. For this reason, we investigated if addition of a low dose of oral ketamine (MIKE: ketamine 3 mg kg-1, midazolam 0.5 mg kg-1) resulted in better premedication compared with oral midazolam 0.5 mg kg-1 or ketamine 6 mg kg-1 alone, in a prospective, randomized, double-blind study. ⋯ In summary, significantly better anxiolysis and separation were observed with a combination of ketamine and midazolam, even in awake children (sedation was not successful according to the preset criteria), than with midazolam or ketamine alone. Duration of action and side effects of the combination were similar to those of midazolam. The combination of both drugs in strawberry flavoured glucose syrup (pH 4.5 approximately) is chemically stable for 8 weeks.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of compound A concentrations with sevoflurane anaesthesia using a closed system with a PhysioFlex anaesthesia machine vs a low-flow system with a conventional anaesthesia machine.
Sevoflurane anaesthesia was conducted using a totally closed circuit PhysioFlex anaesthesia machine (PhysioFlex group) or with a standard Modulus CD anaesthesia machine (Modulus group) (n = 8 in each group). The PhysioFlex was used under closed system conditions and the Modulus was used under low-flow system conditions (flow rate 1 litre min-1). Concentrations of sevoflurane degradation products and the temperature of soda lime were compared. ⋯ Hourly compound A concentrations were lower in the PhysioFlex group than in the Modulus group. End-tidal sevoflurane concentrations during measurement of degradation products were not different between groups. Therefore, use of the totally closed PhysioFlex system may significantly reduce compound A concentrations compared with low-flow anaesthesia using a standard anaesthesia machine.
-
To understand the sequential response of the autonomic nervous system to pregnancy, we studied heart rate variability in 23 first trimester, 23 second trimester and 21 third trimester pregnant women. Twenty non-pregnant women were recruited as controls. Time and frequency domain measures of heart rate variability in three recumbent positions were compared. ⋯ When the position was changed from the supine to the right lateral decubitus, the percentage change in normalized high-frequency power correlated significantly and negatively with normalized high-frequency power in the supine position in non-pregnant controls (r = -0.56, P = 0.01) and in pregnant women in the first (r = -0.44, P = 0.034), second (r = -0.68, P < 0.001) and third (r = -0.68, P < 0.001) trimesters. These results indicate that autonomic nervous activity shifted towards a lower sympathetic and higher vagal modulation in the first trimester, and changed towards a higher sympathetic and lower vagal modulation in the third trimester as gestational age increased. The balance between the haemodynamic changes of pregnancy and aortocaval compression caused by the enlarging gravid uterus may be responsible for the biphasic changes in autonomic nervous activity during pregnancy.
-
Randomized Controlled Trial Clinical Trial
Effect of cricoid pressure on insertion of and ventilation through the cuffed oropharyngeal airway.
We have assessed the effect of cricoid pressure on insertion of and ventilation through the cuffed oropharyngeal airway (COPA) in 53 patients, in a double-blind, randomized study. Two anaesthetists assessed adequacy of ventilation in anaesthetized and paralysed patients at the same time but using different methods. The first assessed ventilation clinically, by observing synchronized chest expansion with gentle manual ventilation and the second noted measurements of tidal volume (VT) and peak inspiratory pressure (PIP). ⋯ Ventilation was clinically 'adequate' in all patients except for one in the cricoid pressure group. There were no significant differences in measured VT or PIP between 'baseline' and 'after manoeuvre' breaths. Significant differences in VT and PIP were found after COPA insertion in the group that received cricoid pressure, with a mean decrease in VT of 108 ml (P = 0.0049) and a mean increase in PIP of 5.2 cm H2O (P = 0.0111).