Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1992
Intraoperative monitoring of tibialis anterior muscle motor evoked responses to transcranial electrical stimulation during partial neuromuscular blockade.
We studied the feasibility of recording motor evoked responses to transcranial electrical stimulation (tce-MERs) during partial neuromuscular blockade (NMB). In 11 patients, compound muscle action potentials were recorded from the tibialis anterior muscle in response to transcranial electrical stimulation during various levels of vecuronium-induced NMB. The level of NMB was assessed by accelerometry of the adductor pollicis muscle after train-of-four stimulation of the ulnar nerve. ⋯ Before administration of vecuronium, the M-response amplitude was 9.6 +/- 3.6 (mean +/- SD) mV, and the tce-MER amplitude was 1.21 +/- 0.66 mV. Although administration of vecuronium (0.05 mg/kg) resulted in loss of the mechanical adductor pollicis response in 8 of the 11 patients, the M-response and the tce-MER remained recordable. Subsequently, during an infusion of vecuronium, adjusted to maintain one or two mechanical responses to train-of-four stimulation, the average M-response to peroneal nerve stimulation was 5.2 +/- 2.5 mV (53% of the control value), and tce-MER amplitude was 0.59 +/- 0.36 mV (59% of the control value).(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Oct 1992
Aspects of mechanical ventilation affecting interatrial shunt flow during general anesthesia.
Intraoperative transesophageal echocardiography was used to study the incidence of flow-patent foramen ovale in 33 normal, healthy patients (ASA physical status I) undergoing general anesthesia in the supine position for nonthoracic surgical procedures. Echocardiographic contrast was injected intravenously during mechanical ventilation in the presence of 0, 5, 10, 15, or 19 cm H2O positive end-expiratory pressure (PEEP). A final test was performed during the release of 19 cm H2O PEEP. ⋯ In all three cases, the shunt flow was accentuated on the release of PEEP; however, no additional cases were detected using this respiratory maneuver. These cases represent the first demonstration of right-to-left interatrial shunting evoked as the result of the sustained application of PEEP. This study also revealed a lower than expected incidence of flow-patent foramen ovale (9%) when measured during general anesthesia and positive pressure ventilation with or without PEEP.
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Anesthesia and analgesia · Sep 1992
Randomized Controlled Trial Comparative Study Clinical TrialMetoclopramide reduces the incidence of vomiting after tonsillectomy in children.
The efficacy of intravenous metoclopramide in controlling vomiting in children after tonsillectomy was determined in a prospective randomized, double-blind investigation. One hundred two unpremedicated, ASA physical status I or II children between the ages of 1 and 15 yr who were undergoing surgical removal of the tonsils, with or without adenoidectomy, were studied. Anesthesia was induced either with halothane, nitrous oxide, and oxygen by mask or by intravenous thiopental and was maintained with halothane, nitrous oxide, oxygen, and intravenous morphine (0.1 mg/kg). ⋯ All episodes of vomiting were recorded for 24 h after completion of surgery. The incidence of vomiting in the saline solution group was 70%, compared with 47% in the metoclopramide group (P = 0.026). The authors conclude that the administration of intravenous metoclopramide in a dose of 0.15 mg/kg on arrival in the postanesthesia care unit significantly decreases the incidence of vomiting in children after tonsillectomy.