Anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
The level of neuromuscular block needed to suppress diaphragmatic movement during tracheal suction in patients with raised intracranial pressure: a study with vecuronium and atracurium.
The effects of tracheobronchial suction before and after neuromuscular blockade with vecuronium (0.12 mg.kg-1; ED95 x 2; group A) and atracurium (0.4 mg.kg-1; ED95 x 2; group B) on intracranial pressure were studied in 18 neurosurgical patients with a Glasgow Coma Scale < 7. Despite adequate sedation, moderate to severe diaphragmatic movements (bucking and coughing) in response to carinal stimulation with significant increases in intracranial pressure (A: 18 SD 7 to 24 SD 8 mmHg; B: 19 SD 7 to 27 SD 5 mmHg) and subsequent decreases in cerebral perfusion pressure (group A: 69 SD 11 to 63 SD 8 mmHg; group B: 63 SD 11 to 59 SD 17 mmHg) could be observed without muscle relaxation. ⋯ Slight diaphragmatic movements could be elicited in only two patients in group A and in two patients in group B during tracheal suction; intracranial pressure (group A: 20 SD 8 to 20 SD 8 mmHg; group B: 19 SD 7 to 19 SD 7 mmHg) and cerebral perfusion pressure (group A: 65 SD 13 to 65 SD 13 mmHg; group B: 66 SD 12 to 65 SD 11 mmHg) remained unchanged. When coordinating respiratory therapy in neurosurgical intensive care patients, profound neuromuscular block, quantified by a post-tetanic count of at least 5 for vecuronium and 1 for atracurium, it is necessary to rule out any impact of diaphragmatic movement on intracranial pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
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Comparative Study
The measurement of right ventricular ejection fraction by thermodilution. A comparison of values obtained using differing injectate ports.
Thermodilution measurements of cardiac output and right ventricular ejection fraction were obtained using a rapid response pulmonary artery catheter. Values were compared when injectate was administered via either a cannula within the right internal jugular vein or the dedicated right atrial port of the pulmonary artery catheter. Mean (SD) bias for cardiac output and right ventricular ejection fraction measurements were 0.08 (0.32) l.min-1 and 2.6 (6.6)% respectively. We therefore conclude that both injectate techniques will provide similar values for cardiac output but dissimilar values for right ventricular ejection fraction measurement.
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A constant pressure differential valve for the control of tracheal tube cuff pressure was tested under clinical conditions. Fifty-one patients underwent controlled ventilation and 20 patients were allowed to breathe spontaneously. Nitrous oxide 66% with oxygen 33% and halothane were used via a circle system. ⋯ Fifty-two control patients had the same incidence of sore throat (40%) and hoarseness (30%) at 24 h. With spontaneous ventilation, fresh gas flows of 5-15 l.min-1 maintained the cuff pressure above 10 cmH2O. We conclude that this valve prevents excessive tracheal cuff pressure while maintaining the airway seal.