Canadian journal of anaesthesia = Journal canadien d'anesthésie
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The increases in tension at the masseter and adductor pollicis muscles following succinylcholine, 1 mg.kg-1, during halothane anaesthesia were measured in eight children, 3-10 yr, with strabismus. The results were compared with those obtained in a control group of general surgical patients. Supramaximal train-of-four (TOF) stimulation was applied to the ulnar nerve and the nerve to the masseter simultaneously. ⋯ The duration of the phenomenon was 1-2 min in both muscles studied, and was not statistically different in the strabismus group. Time to complete neuromuscular blockade was significantly faster at the masseter, 31 +/- 6 sec--control groups; 39 +/- 11 sec--strabismus group, than at adductor pollicis, 61 +/- 34 sec--control groups; 75 +/- 28 sec--strabismus group (P less than 0.05 and 0.013 respectively). It is concluded that succinylcholine causes similar increases in jaw tension and comparable degrees of neuromuscular blockade in patients undergoing strabismus surgery as in other children.
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Randomized Controlled Trial Clinical Trial
Large volumes of apple juice preoperatively do not affect gastric pH and volume in children.
The effect on gastric pH and volume of 0, 6 and 10 ml.kg-1, of apple juice given 2.5 hours before surgery to children aged five to ten years was investigated in this prospective, randomized, single-blind study. Gastric contents were aspirated after induction of anaesthesia, and the volume measured. The pH of the gastric aspirate was then assessed using pH paper. ⋯ Gastric volumes after 0, 6 and 10 ml.kg-1, of juice averaged (mean +/- SD) 0.45 +/- 0.31, 0.66 +/- 0.79 and 0.71 +/- 0.76 ml.kg-1, respectively; gastric pH averaged 1.7 +/- 0.6, 1.7 +/- 0.6 and 1.8 +/- 0.8, respectively. On the basis of questions asked immediately before induction of anaesthesia, patients who drank 6 ml.kg-1 of apple juice had decreased thirst and were less irritable and upset before anaesthesia than those who had not (P less than 0.05). It is concluded that drinking large volumes of clear apple juice 2.5 hours before scheduled surgery does not have a measurable effect on gastric volume and pH and may offer benefits such as improved patient comfort.
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Comparative Study
A clinical comparison of indices of pulmonary gas exchange with changes in the inspired oxygen concentration.
Several indices have been introduced as convenient alternatives to calculation of the physiological shunt fraction (Qs/QT) for the assessment of pulmonary gas exchange. These include: the arterial-alveolar oxygen tension ratio (a/APO2), the arterial oxygen tension-inspired oxygen concentration ratio (PaO2/FIO2), the respiratory index (RI), [A-a)DO2/PaO2) and the alveolar-arterial oxygen tension difference [A-a)Do2). These indices are in use clinically despite the fact that they may not accurately predict gas exchange in situations where FIO2, Qs/QT or arterial-venous oxygen content is changing. ⋯ As FIO2 was increased incrementally from 0.30 to 1.00, 42 to 55 per cent of the measured changes in these indices were opposite in direction to the corresponding changes in the physiological shunt. The maximum magnitudes of the opposite changes were substantial; 24 and 22 per cent for the a/APO2 and PaO2/FIO2 ratio respectively, 67 per cent for the RI and 101 per cent for the (A-a)DO2. We conclude that the use of any of these indices for clinical assessment of a patient's gas exchange defect when FIO2 is varying can be substantially misleading.
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Anaesthetists are responsible for the management of the airway in patients with unstable cervical spines. Unfortunately, the anaesthetic literature does not contain a recent, critical analysis of the current medical literature to aid anaesthetists attending such patients. This review is intended to serve such a purpose. ⋯ Relevant findings included the high prevalence of cervical spinal instability in such disorders such as Trisomy 21 and rheumatoid arthritis and the relatively low incidence after trauma. There are deficiencies in the minimalist approaches to assessing the cervical spine, such as a simple cross table lateral radiograph after trauma, as they are neither sensitive nor specific. Finally, recognizing the potential for instability and intubating with care, while avoiding spinal movement, appears to be more important than any particular mode of intubation in preserving neurological function.
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Au cours de 18 cœlioscopies chez des jeunes femmes A. S. A. status physique 1, les conséquences hémodynamiques du pneumopéritoine et de la position de Trendelenburg ont été évaluées par la méthode non invasive de bioimpédance électrique thoracique. ⋯ Elevated intra-abdominal pressure was also associated with a significant increase in mean arterial pressure (from 68 to 88 mmHg) and systemic vascular resistance index (from 1620 to 2491 dyn · s · cm-5· m-2). However, values were not restored after peritoneal exsufflation: systemic vascular resistance index values remained 30 per cent higher than that before insufflation. Decreased venous return may account for the significant decrease in cardiac output but mechanical compression does not explain the persistent elevation of systemic vascular resistance.