Effects of priming with pancuronium or rocuronium on intubation with rocuronium in children.
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Rocuronium is a non-depolarizing neuromuscular blocking agent which has a rapid onset and intermediate duration of action. The goal of this study was to compare the neuromuscular blocking actions of rocuronium with and without a priming dose of pancuronium or rocuronium in children. Thirty patients were randomly allocated into 3 groups. Ten patients received a single dose of 0.6 mg/kg rocuronium (Group I). The others received either 0.015 mg/kg pancuronium (Group II) or 0.06 mg/kg rocuronium (Group III) 3 minutes before an intubating dose of 0.54 mg/kg rocuronium was given. Neuromuscular blockade was measured via accelerographic response to single stimulations (1 Hz) of the ulnar nerve until maximal twitch depression was reached followed by train-of-four (TOF) stimuli (2 Hz) at 15 second intervals for the remainder of recovery. Groups were compared with regard to onset time, duration and recovery indices. The onset time and duration of block did not differ significantly between groups. However, the time to recovery in group II (24.5 +/- 9.9 min) was significantly prolonged compared to that in group I (12.7 +/- 3.1 min) or group III (12.7 +/- 3.9 min). We concluded that the use of rocuronium with a preceding dose of either pancuronium or rocuronium provided no advantage for intubation in children. (+info)
Paralysis of ventilated newborn babies does not influence resistance of the total respiratory system.
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Paralysis with pancuronium bromide is used in newborn infants to facilitate ventilatory support during respiratory failure. Changes in lung mechanics have been attributed to paralysis. The aim of this study was to examine whether or not paralysis per se has an influence on the passive respiratory mechanics, resistance (Rrs) and compliance (Crs) of the respiratory system in newborn infants. In 30 infants with acute respiratory failure, Rrs was measured during paralysis with pancuronium bromide and after stopping pancuronium bromide (group A). Rrs was also measured in an additional 10 ventilated infants in a reversed fashion (group B): Rrs was measured first in nonparalysed infants and then they were paralysed, mainly for diagnostic procedures, and the Rrs measurement repeated. As Rrs is highly dependent on lung volume, several parameters, that depend directly on lung volume were recorded: inspiratory oxygen fraction (FI,O2), arterial oxygen tension/alveolar oxygen tension (a/A) ratio and volume above functional residual capacity (FRC). In group A, the Rrs was not different during (0.236+/-0.09 cmH2O x s x mL(-1)) and after (0.237+/-0.07 cmH2O x s x mL(-1)) paralysis. Also, in group B, Rrs did not change (0.207+/-0.046 versus 0.221+/-0.046 cm x s x mL(-1) without versus with pancuronium bromide). FI,O2, a/A ratio and volume above FRC remained constant during paralysis. These data demonstrate that paralysis does not influence the resistance of the total respiratory system in ventilated term and preterm infants when measured at comparable lung volumes. (+info)
Effects of non-depolarizing neuromuscular blocking agents on norepinephrine release from human atrial tissue obtained during cardiac surgery.
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We have studied the effect of non-depolarizing neuromuscular blocking agents, at concentrations present in serum during anaesthesia, on release of [3H]-norepinephrine ([3H]NE) from superfused atrial appendage obtained during cardiac surgery from 48 patients. Three of the neuromuscular blocking agents (pancuronium, gallamine and rocuronium), which are known to cause an increase in heart rate during anaesthesia, increased stimulation-evoked release of [3H]NE. In contrast, (+)tubocurarine and pipecuronium, neuromuscular blocking agents that do not cause tachycardia, did not affect release of NE. Org 9487 significantly enhanced release while SZ1677 was ineffective, even at concentrations higher than those expected after administration of a 2 x ED95 dose. Atropine enhanced release. These data suggest that the axon terminals of sympathetic nerves in human heart have muscarinic heteroreceptors whose activation by acetylcholine (ACh) released from the vagal nerve reduces release of NE. This action contributes to lowering of heart rate. Therefore, any neuromuscular blocking agent with antimuscarinic actions and capable of increasing the release of NE may produce tachycardia. (+info)
Residual neuromuscular block caused by pancuronium after cardiac surgery.
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We studied 20 adult patients undergoing cardiac surgery. All received pancuronium as the sole neuromuscular blocking drug and no reversal agent was used. In the postoperative intensive care unit, mechanical ventilation was continued and patients were sedated with an infusion of propofol. Neuromuscular block was measured electromyographically at appropriate intervals until the train-of-four ratio (TOF) reached 0.8. At the time when the propofol infusion would normally be discontinued, 13 patients (65%) demonstrated a TOF of less than 0.8 (group median 0.23, interquartile range 0.11-0.6). Subsequently, the median time to achieve a TOF of 0.8 was 2 h 10 min (interquartile range 1 h-2 h 25 min). We found that if pancuronium was used during cardiac surgery, a significant proportion of patients remained partially paralysed when they would normally be allowed to emerge from anaesthesia in the ICU. (+info)
Evidence for a peripheral mechanism of esophagocrural diaphragm inhibitory reflex in cats.
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The esophagogastric junction (EGJ) is guarded by two sphincters, a smooth muscle lower esophageal sphincter (LES) and a skeletal muscle crural diaphragm. These two sphincters relax simultaneously under certain physiological conditions, i.e., swallowing, belching, vomiting, transient LES relaxation, and esophageal distension. Esophageal distension-induced crural diaphragm relaxation is mediated through vagal afferents that are thought to exert inhibitory influence on the central mechanism (brain stem) of crural diaphragm contraction. We conducted studies in 10 cats to determine whether a mechanism of crural diaphragm relaxation was located at the level of the neuromuscular junction and/or muscle. Stimulation of the crural diaphragm neuromuscular junction through 1) the electrodes implanted in the muscle and 2) the bilateral phrenic nerve resulted in an increase in EGJ pressure. Nicotinic receptor blockade (pancuronium, 0.2 mg/kg) abolished the EGJ pressure increase caused by electrical stimulation of the neuromuscular junction. Esophageal distension and bolus-induced secondary esophageal peristalsis caused relaxation of the EGJ during the stimulation of the neuromuscular junction. Bilateral phrenicotomy and vagotomy had no influence on this relaxation. These data suggest the existence of a peripheral mechanism of crural diaphragm inhibition. This peripheral inhibitory mechanism may reside at the level of either the neuromuscular junction or the skeletal muscle. (+info)
Effect of pipecuronium and pancuronium on intracranial pressure and cardiovascular parameters in patients with supratentorial tumours.
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A prospective, randomised, single blind study was conducted to evaluate and compare the intracranial pressure (ICP) and cardiovascular effects of pipecuronium (PPC) and pancuronium (PNC) in 20 patients undergoing supratentorial surgery. Patients were randomly divided into two groups. Patients in Group I (n = 10) received pancuronium (0.1 mg kg(-1)) and in Group II (n = 10) pipecuronium (0.07 mg kg(-1)) for intubation. Intracranial pressure (ICP), heart rate (HR), systolic, diastolic and mean arterial pressures (SAP, DAP, MAP), central venous pressure (CVP), nasopharyngeal temperature and arterial blood gases (ABG) were monitored at the following time periods: before induction (0 minutes); 3 minutes after thiopentone and muscle relaxant; immediately after intubation; and 4, 6, 8, 10, 20 and 30 minutes following intubation. The rise in intracranial pressure at intubation was significantly greater in group I (21.10+/-3.97 torr, 122.59%) when compared to group II patients (1.80+/-0.70 torr, 10.04%) (p<0.0 1). Cardiovascular parameters also showed a significantly greater degree of rise in group I when compared to group II patients. Heart rate increased by 29+/-6.32 beats min(-1) (33.52%) and systolic arterial pressure by 11.60+/-7.37 torr (9.47%) in group I. These parameters did not change significantly in group II. No significant alterations were observed in the other measured parameters in either of the two groups. (+info)
Prolongation of pancuronium-induced neuromuscular blockade by intravenous infusion of nitroglycerin.
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Based upon clinical observation of undue prolongation of pancuronium-induced blockade in the presence of intravenous infusion of nitroglycerin, neuromuscular blockades produced by pancuronium, succinylcholine and d-tubocurarine were studied in 51 cats using the sciatic-gastrocnemius nerve-muscle preparation. Pancuronium-induced blockade was found to be significantly prolonged (P less than 0.1) in the presence of a nitroglycerin infusion of 1 microgram/kg/min (65 vs. 127 min). Less, but still significant, prolongation occurred when nitroglycerin, 0.5 microgram/kg/min, was infused. The intravenous infusion of nitroglycerin must be started prior to the pancuronium injection for the block to be prolonged. Neuromuscular blocks produced by succinylcholine and d-tubocurarine were not altered by nitroglycerin. In experiments using the isolated rat diaphragm preparation, the depth of pancuronium-induced block was found not to be changed by nitroglycerin, suggesting an effect of nitroglycerin on the process of recovery from blockade. These findings indicate a selective pancuronium-nitroglycerin interaction. (+info)
Postoperative residual paralysis and respiratory status: a comparative study of pancuronium and vecuronium.
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The objective of this prospective double-blind study was to determine whether postoperative residual paralysis (PORP) after pancuronium or vecuronium results in hypoxemia and hypercapnia in the immediate admission period to the recovery ward. Eighty-three consecutive surgical patients received balanced or intravenous anesthesia with pancuronium for operations lasting longer than one hour or vecuronium for those lasting less than 60 min, both combined with neostigmine at the end of anesthesia. Standard clinical criteria assessed neuromuscular function intraoperatively. Postoperatively, we determined neuromuscular function (acceleromyography with supramaximal train-of-four (TOF) stimulation of the ulnar nerve, and a 5-s head lift) and pulmonary function (pulse oximetry: SpO2, and blood gas analysis: SaO2, PaCO2). We defined PORP as a TOF-ratio <70%, hypoxemia as a postoperative SpO2 > or =5% below the pre-anesthestic level together with a postoperative SaO2 <93%, and hypercapnia as a PaCO2 > or =46 mm Hg. Among the 49 pancuronium and 27 vecuronium patients studied, the PORP rates were 20% in the pancuronium group and 7% in the vecuronium group (p>0.05). Hypoxemia and hypercapnia occurred more often in pancuronium patients with PORP than in those without PORP namely 60% vs. 10% (p<0.05) and 30% vs. 8% (p>0.05), respectively. We conclude that PORP after pancuronium is a significant risk factor for hypoxemia. (+info)