Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1997
Clinical TrialDynamic ventilatory characteristics during weaning in postoperative critically ill patients.
Postoperative patients occasionally require more than 48 h of mechanical ventilation. This study examined whether there were distinct differences in dynamic respiratory variables between patients who successfully weaned from mechanical ventilation and those who failed. Forty general and thoracic surgery patients underwent a standardized weaning sequence: 25 min of synchronous intermittent mandatory ventilation (SIMV) at 8 bpm plus 5 cm H2O pressure support ventilation (PSV), then SIMV at 4 bpm plus 5 cm H2O PSV, followed by continuous positive airway pressure (CPAP) plus 5 cm H2O PSV and, finally, CPAP without PSV. ⋯ P0.1 (threshold 4.5 cm H2O, sensitivity 1.00, specificity 1.00), patient work of breathing (threshold 1.3 J/L, sensitivity 0.92, and specificity 0.98), and the sRR/sV(T) ratio (threshold 65 bpm/L, sensitivity 0.90, specificity 0.80) were distinctive. Most unique was the analysis of spontaneous breaths during low SIMV rates. This appears to permit an early determination of whether weaning would succeed.
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Anesthesia and analgesia · Jun 1997
Randomized Controlled Trial Clinical TrialThe effect of intradermal administration of lidocaine and morphine on the response to thermal stimulation.
Opioids appear to exert a peripheral effect by gaining access to peripheral opioid receptors. It has been proposed that inflammatory processes and highly osmotic substances could alter the perineural barrier, thereby allowing easy access to opioid receptors. Although local anesthetics do not have osmotic activity, they are highly active on neural tissue and appear to work synergistically with opioids when administered for major conduction blockade. ⋯ Pain scores indicated that the combination of lidocaine plus morphine was not more effective than lidocaine alone in attenuating the heat-induced pain. Twenty and 120 min after injection, scores at the lidocaine plus morphine site were 37% and 20% greater than those at the lidocaine site. The addition of morphine to lidocaine did not result in an improvement in the analgesic efficacy and actually had an antianalgesic effect.
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Anesthesia and analgesia · Jun 1997
Case Reports Randomized Controlled Trial Clinical TrialGlossopharyngeal nerve block for pain relief after pediatric tonsillectomy: retrospective analysis and two cases of life-threatening upper airway obstruction from an interrupted trial.
A regional anesthetic technique formerly used in adults for tonsillectomy was adapted to provide posttonsillectomy pain relief in children. Injection of 3-10 mL of 0.25%-0.5% bupivacaine into each lateral pharyngeal space appeared to provide good postsurgical analgesia. A retrospective chart review failed to link the technique to airway-related complications. ⋯ We conclude that the volume and concentration of bupivacaine were sufficient to block the vagus nerves proximal to the take off of the recurrent laryngeal nerves and/or the hypoglossal nerves, resulting in severe UAO. The short distance between the hyoid and jugular foramen would predispose children and adults with a short neck to the development of this complication. In conclusion, bilateral local anesthetic injection into the lateral pharyngeal space may result in severe UAO and loss of protective reflexes.
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Anesthesia and analgesia · Jun 1997
Randomized Controlled Trial Clinical TrialSpinal anesthesia with meperidine. Effects of added alpha-adrenergic agonists: epinephrine versus clonidine.
We determined the effects of intrathecally administered epinephrine and clonidine on the duration and quality of a meperidine spinal block. Forty-five patients scheduled for orthopedic surgery, divided into three groups, received spinal anesthesia with 1 mg/kg 5% meperidine, alone or with 200 microg epinephrine or 2 microg/kg clonidine. Using a double-blind method, the onset, extension, and duration of sensory block (to pinprick) and the duration and degree of motor block (Bromage scale) were assessed. ⋯ Only the addition of clonidine prolonged the postoperative analgesia (P<0.001), but was associated with an increased sedation score. The incidence of other side effects did not differ between the groups. We conclude that coadministration of epinephrine or clonidine with meperidine enhances the duration and degree of spinal anesthesia and that adding clonidine prolongs the duration of postoperative analgesia.
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Anesthesia and analgesia · Jun 1997
Randomized Controlled Trial Clinical TrialEvaluation of residual neuromuscular block using train-of-four and double burst stimulation at the index finger.
We examined the percentage of tactile detection of fade in response to train-of-four (TOF), double burst stimulation3,3 (DBS3,3), or DBS3,2 at the index finger compared with that at the thumb during continuous infusion of vecuronium. One hundred five adult patients were studied. At TOF ratios (T4/T1) of 0.41-0.70, fades in response to TOF were more frequently identified by tactile means at the index finger than at the thumb (58% vs 26%, P < 0.05). ⋯ The baseline displacement of the index finger was significantly less than that of the thumb (P < 0.05). In summary, the percentage of tactile detection of fade in response to neurostimulation at the index finger is higher than at the thumb, and the absence of fade in response to DBS3,3 at the index finger is a good indicator of adequate recovery from neuromuscular block. This is probably because of the smaller baseline displacement of the index finger.