Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Neuromuscular blocking agents are frequently used in the Intensive Care Unit to facilitate tracheal intubation and the application of continuous paralysis. This review will focus on various conditions of the critically ill patient such as multi-organ dysfunction, acid-base and electrolyte imbalance, prolonged immobility, multiple drug interactions and specific disease/injury processes that may affect the pharmacokinetic and pharmacodynamic behaviour of muscle relaxants. As such, due to the complex nature of the critically ill patients, the effects of neuromuscular blocking agents are unpredictable. Therefore, guidelines regarding their administration and the methodology and requirement for continuous bedside monitoring of neuromuscular function will be presented.
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Randomized Controlled Trial Clinical Trial
Spinal anaesthesia with lidocaine 2% for caesarean section.
Spinal anaesthesia with 2, 2.5 or 3 ml of glucose-free lidocaine 2% was studied in 50 patients undergoing Caesarean section. Onset time, cephalad spread of analgesia, quality of analgesia, muscle relaxation, the cardiovascular effects and duration of analgesia and motor block were assessed. Reliable anaesthesia was provided with 2.5 and 3 ml while 2 ml of 2% lidocaine was insufficient. ⋯ Hypotension (SBP < 100 mmHg) was noted in 10% (n = 5) of patients in whom the cephalad spread of analgesia was also higher. All the neonates had an apgar score of 7 or more at 1 min. These results suggest that 2.5 to 3 ml of 2% lidocaine provides satisfactory anaesthesia for Caesarean section.
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Randomized Controlled Trial Comparative Study Clinical Trial
Continuous infusions of atracurium and vecuronium, compared with intermittent boluses of pancuronium: dose requirements and reversal.
This study was designed to determine the effect of prolonged infusion on the ease of reversal of atracurium and vecuronium, and whether factors which potentiate the block delayed reversal. In phase one, 40 patients were randomized (double blind) to determine the steady state conditions for atracurium and vecuronium. Fourteen atracurium patients and 17 vecuronium patients were evaluable. ⋯ The addition of an inhalation agent to atracurium reduced the infusion rate by 2.01 +/- 0.28 micrograms.kg-1 x min-1 (P = 0.0001) for each increase in MAC. The mean reversal times for atracurium with three different anaesthetics and for vecuronium were not different. Reversal of pancuronium blockade, from less profound twitch depression (86.4 vs 95%) took twice as long as for atracurium and vecuronium for which the following predictors were identified: age, weight, duration of infusion, level of blockade, and type of anaesthetic, using a stepwise regression model.(ABSTRACT TRUNCATED AT 250 WORDS)
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The purpose of this review is to emphasise the ineffectiveness of traditional analgesic therapy in paediatric patients after surgery, to examine the sensation of pain in infants and children, and to describe the use of intravenous opioids for postoperative analgesia. The management of acute postoperative pain in the paediatric surgical population has been poor. This is despite the knowledge that infants and children have sufficient neurological development at birth to sense pain, and that the same hormonal and metabolic responses to nociceptive stimuli that occur in adult also occur in the neonate. ⋯ Two of these, continuous intravenous opioid infusion and patient-controlled analgesia, have proved to be very successful. Children older than six months can receive either modality safely with regular monitoring by qualified nursing staff. Infants younger than six months receiving continuous opioid infusions should be monitored in high-dependency units.
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Capnography is a useful technique in monitoring the integrity of anaesthetic equipment such as the malfunctioning of unidirectional valves in circle system. However, the lack of a precise mechanism in existing capnographs to identify the start of inspiration and the beginning of expiration in the capnograms, makes the analysis of the carbon dioxide waveforms during inspiration difficult and thus results in inaccurate assessment of rebreathing. We report a case where, during the malfunction of the inspiratory unidirectional valve in the circle system, the capnograph failed to detect the presence of substantial rebreathing. Critical analysis of the capnogram recorded during the malfunction revealed that there was substantial rebreathing which was underestimated by the capnograph as it reports only the lowest CO2 concentration rebreathed during inspiration in such abnormal situations.