Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1995
Randomized Controlled Trial Clinical TrialThe optimal distance that a multiorifice epidural catheter should be threaded into the epidural space.
Complications can occur during epidural placement for women in labor. As many as 23% of epidural anesthetics may not provide satisfactory analgesia. The cause of this may be technical. ⋯ Fifteen minutes later, the adequacy of the analgesia was assessed by a blinded observer. We found that catheter insertion to a depth of 7 cm was associated with the highest rate of insertion complications while insertion to a depth of 5 cm was associated with the highest incidence of satisfactory analgesia. For women in labor who require continuous lumbar epidural anesthesia, we recommend threading a multiorifice epidural catheter 5 cm into the epidural space.
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Anesthesia and analgesia · Aug 1995
Randomized Controlled Trial Comparative Study Clinical TrialThe use of the laryngeal mask airway in children with bronchopulmonary dysplasia.
Airway maintenance with the laryngeal mask airway (LMA) was evaluated and compared to the endotracheal (ET) tube in 27 former premature infants and children with bronchopulmonary dysplasia (BPD) during second stage open-sky vitrectomy. The children were randomly assigned to a study group and anesthetized with halothane in N2O:O2. The airway was maintained with the LMA (n = 13) or the ET tube (n = 14). ⋯ The incidence of coughing, with and without desaturation, wheezing, and hoarseness in the postoperative period was higher in the ET tube group. Awakening, after discontinuation of the anesthetic (P < 0.01) was more rapid, and home discharge time (P < 0.002) was shorter in the LMA group (P < 0.0025), although our study design could not isolate the use of the LMA as the factor responsible for this. This study in patients with mild chronic lung disease demonstrated that the LMA can maintain a satisfactory airway during minor surgical procedures in children with bronchopulmonary dysplasia and result in fewer respiratory adverse effects than with the ET tube.
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Anesthesia and analgesia · Aug 1995
Fentanyl, clonidine, and repeated increases in desflurane concentration, but not nitrous oxide or esmolol, block the transient mydriasis caused by rapid increases in desflurane concentration.
Initial, but not subsequent, inhalation of 8% desflurane produces transient sympathetic stimulation. We hypothesized that initial but not subsequent increases should produce pupil dilation, and that N2O, fentanyl, and clonidine, but not esmolol, should blunt the response. In 10 volunteers, we maintained anesthesia with 4% end-tidal desflurane in oxygen for 32 min, then increased the concentration to 8% for 10 min. ⋯ Fentanyl 1.5 micrograms/kg and 4.5 micrograms/kg decreased peak diameter (2.3 +/- 0.9 and 1.6 +/- 0.3 mm), as did clonidine (2.3 +/- 1.7 mm) but not esmolol. We conclude that, concurrent with sympathetic stimulation, an initial rapid increase in desflurane concentration transiently increases pupil diameter, whereas repeated increases produce attenuated responses. N2O augments, fentanyl and clonidine attenuate, and esmolol does not affect the response.
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Anesthesia and analgesia · Aug 1995
Comparative StudyComparison of the effects of halothane, isoflurane, and sevoflurane on atrioventricular conduction times in pentobarbital-anesthetized dogs.
It is not known how sevoflurane affects the cardiac conduction system. We compared the effects of halothane, isoflurance, and sevoflurane on specialized atrioventricular (AV) conduction times in eight pentobarbital-anesthetized dogs. AV conduction times with three inhaled anesthetics at end-tidal concentrations of 1 and 2 minimum alveolar anesthetic concentration (MAC), were measured by His-bundle electrocardiography during both sinus rhythm and right atrial pacing at a slightly higher rate than sinus one. ⋯ No significant difference in AV conduction times was observed between isoflurane and sevoflurane. Heart rate during sinus rhythm remained unchanged despite a decrease in arterial pressure with three inhaled anesthetics. The property of sevoflurane and isoflurane which does not affect the cardiac conduction system may be important in the stability of the cardiac rhythm during anesthesia with these drugs.
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Anesthesia and analgesia · Aug 1995
Case ReportsTransient neurologic deficit after spinal anesthesia: local anesthetic maldistribution with pencil point needles?
Recent reports of transient neurologic deficits have raised concern about the potential toxicity of single-dose spinal 5% lidocaine in 7.5% dextrose. Two cases of volunteers who experienced minor local sensory deficits after slow (60 s) injections of 2 mL 5% lidocaine via Whitacre needles are described. One case was a result of a double injection because of a "failed" block. ⋯ Triplicate injections were done at rapid (2 mL/10 s) and slow (2 mL/60 s) rates, with needle side ports oriented in a sacral and cephalad direction. At slow rates of injection, using 27- or 25-gauge sacrally directed Whitacre needles, injections showed evidence of maldistribution with extrapolated peak sacral lidocaine concentrations reaching 2.0%. In contrast, distribution after slow injection through sacrally directed Quincke needles was uniform.(ABSTRACT TRUNCATED AT 250 WORDS)