British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Influence of induction technique on intubating conditions after rocuronium in adults: comparison with rapid-sequence induction using thiopentone and suxamethonium.
We have assessed the effect of anaesthetic technique on intubating conditions after rocuronium 0.6 mg kg-1 in four groups (n = 25 each) of unpremedicated patients in whom anaesthesia was induced with either thiopentone 5 mg kg-1 or propofol 2.5 mg kg-1 alone, or supplemented with alfentanil 20 micrograms kg-1. Fifty control patients were anaesthetized with thiopentone followed by suxamethonium. Laryngoscopy was commenced at 45 s. ⋯ However, intubation time was similar in all five groups and averaged 55 (SD 3.2) s, and the tube could be passed through open vocal cords within 70 s. After rocuronium the response of the diaphragm to intubation was more pronounced in the two groups of patients not receiving alfentanil (P < 0.0001) and in patients anaesthetized using propofol with alfentanil (P < 0.01) than in the control group. Opioids (in doses equivalent to alfentanil 20 micrograms kg-1) constitute an integral part of an induction regimen containing rocuronium 0.6 mg kg-1, regardless of whether or not thiopentone or propofol is used, in order to achieve overall intubating conditions similar to those after suxamethonium.
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Comparative Study Clinical Trial Controlled Clinical Trial
Thoracic impedance used for measuring chest wall movement in postoperative patients.
Thoracic impedance (TTI) and rib cage inductance band (IB) signals were measured in 10 patients during the first night after abdominal surgery, and compared by successive correlation of the change in each signal. Poor matching of the signals occurred, on average, for 94 min either because of movement of differences in the waveform. There were frequent episodes of transient poor correlation, generally associated with transient respiratory disturbance, predominantly airway obstruction (58%). Thoracic impedance measurements are simpler than inductance band methods for detecting rib cage movement and may be useful for large studies of respiratory abnormalities in patients after operation.
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Randomized Controlled Trial Comparative Study Clinical Trial
Intubating conditions and time course of rocuronium-induced neuromuscular block in children.
We have investigated the potential of rocuronium 0.6 mg kg-1 (2xED95) and 0.9 mg kg-1 (3xED95) for rapid sequence induction in 100 children, aged 3-7 yr. Intubating conditions with the two different doses of rocuronium were assessed in 70 children (n = 35 in each group) undergoing elective surgery. Intubation was carried out by mimicking rapid sequence induction, and intubation conditions were evaluated according to a standard score. ⋯ Three times the ED95 induced deeper neuromuscular block, 1 min after injection compared with 2xED95 (twitch height: 42 (24) vs 25 (19)%, respectively; P < 0.05). The same was true for onset time (193 (47) vs 118 (23) s; P < 0.01), clinical duration (21 (4) vs 34 (11) min; P < 0.01) and duration to 75% recovery (30 (6) vs 44 (4) min; P < 0.01). By mimicking rapid sequence induction, both doses of rocuronium offered clinically acceptable (good or excellent) intubating conditions.
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Clinical Trial
Sternomental distance as the sole predictor of difficult laryngoscopy in obstetric anaesthesia.
Sternomental distance and view at laryngoscopy were documented in 523 parturients undergoing elective or emergency Caesarean section under general anaesthesia. Eighteen (3.5%) had a grade III or IV laryngoscopic view (Cormack and Lehane's classification) and were classified as potentially difficult tracheal intubations. There was a significant difference between sternomental distance in those patients with a grade III or IV laryngoscopic view compared with those with a grade I or II (13.17 (SD 1.54) cm vs 14.3 (1.49) cm; P = 0.0013). ⋯ A sternomental distance of 13.5 cm or less had a sensitivity, specificity, positive and negative predictive values of 66.7%, 71.1%, 7.6% and 98.4%, respectively. While there was no association between sternomental distance and age, weight, height or body mass index (BMI), there was a significant association between grade of laryngoscopy (III and IV) and older (P = 0.049) and heavier (P = 0.0495) mothers. The results suggest that while sternomental distance on its own may not be an adequate sole predictor of subsequent difficult laryngoscopy the measurement should be incorporated into a series of quick and simple preoperative tests.
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Comparative Study
Inflammatory changes after extradural anaesthesia may affect the spread of local anaesthetic within the extradural space.
We have assessed cephalad spread of analgesia in 491 patients undergoing extradural anaesthesia at the L2-3 or L3-4 interspace. Patients were classified into one of three groups based on the number of previous lumbar extradural anaesthesia procedures: none (group I, n = 339), one (group II, n = 82), and two or more (group III, n = 70). ⋯ Extraduroscopy showed the extradural space to be patent in patients with no history of prior lumbar extradural anesthesia, but it was not clearly identified in patients who had received extradural anaesthesia one or more times because of aseptic inflammatory changes, including proliferation of connective tissue, adhesions between the dura mater and the ligamentum flavum, granulation and changes in the ligamentum flavum. Extradural anaesthesia may cause aseptic inflammatory changes in the extradural space which may reduce the spread of analgesia.