Anesthesia and analgesia
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Anesthesia and analgesia · Oct 2003
Clinical TrialSevoflurane in exhaled air of operating room personnel.
Evidence on potential health hazards arising from exposure to volatile anesthetics remains controversial. Exposure may, in principle, be supervised by monitoring of ambient air or, alternatively, in vivo. We used the Proton Transfer Reaction-Mass Spectrometry to screen the breath of 40 operating room staff members before operating room duty, 0, 1, 2, and 3 h after duty, and before commencing duty on the consecutive day, and control persons. Staff members exhibited significantly increased sevoflurane levels in exhaled air after duty, with a mean of 0.80 parts per billion as compared with baseline values of 0.26 parts per billion (P < 0.05). Analysis of variance with adjustment for within correlation (repeated measurements) showed a statistically significant time-effect (P < 0.001). We conclude that (a) Proton Transfer Reaction-Mass Spectrometry biomonitoring of exhaled sevoflurane can serve as a simple and rapid method to determine volatile anesthetic excretion after occupational exposure, and (b) significant concentrations of sevoflurane may be continuously present in persons exposed to sevoflurane on a daily basis. ⋯ The present study depicts the profile of volatile anesthetics, isoflurane and sevoflurane, in exhaled air of ambulatory patients. Biomonitoring of expired anesthetic concentrations is a noninvasive and rapid method to determine volatile anesthetic excretion.
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Anesthesia and analgesia · Oct 2003
Randomized Controlled Trial Clinical TrialContinuous wound infiltration with ropivacaine reduces pain and analgesic requirement after shoulder surgery.
After achieving a reduction of pain scores for 10 h with a single dose wound infiltration after shoulder surgery, we examined in a prospective, placebo-controlled and double-blinded study the analgesic effects of continuous wound infiltration with different concentrations of ropivacaine. Forty-five patients undergoing shoulder surgery were randomly assigned into three groups to receive single dose wound infiltration with 30 mL saline (group S) or ropivacaine 7.5 mg/mL (groups R2 and R3.75) after skin closure. Postoperatively, patients received a continuous wound infiltration with saline (group S), ropivacaine 2 mg/mL (group R2) or ropivacaine 3.75 mg/mL (group R3.75) for 48 h. Supplemental pain relief was provided by IV patient-controlled analgesia with the opioid piritramide. At 1, 2, 3, 4, 24, and 48 h postoperatively visual analogue scale (VAS) values (0-100 mm), piritramide requirements and side effects were registered. Plasma levels of ropivacaine were measured preoperatively and at 24 h and 48 h after surgery. Until 48 h VAS values were smaller in group R3.75 compared with group S (group R3.75, 8 +/- 9 mm; group S, 31 +/- 14 mm; P < 0.005), whereas 4 h and 48 h postoperatively VAS values were even smaller in group R3.75 compared with group R2 (P < 0.05). Cumulative piritramide consumption was always smaller in groups R2 and R3.75 compared with group S (1-24 h, P < 0.005; 48 h, P < 0.05). Plasma ropivacaine levels remained less than the toxic threshold. We conclude that continuous postoperative wound infiltration with ropivacaine, especially using 3.75 mg/mL, provides smaller VAS values and opioid requirement in comparison with saline after shoulder surgery. ⋯ The continuous postoperative wound infiltration after shoulder surgery with different concentrations of ropivacaine, 2 mg/mL and 3.75 mg/mL, results in lower pain scores and opioid requirement compared with infiltration with placebo. Plasma levels of ropivacaine remained less than the toxic threshold.
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Anesthesia and analgesia · Oct 2003
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of psoas compartment block and spinal and general anesthesia for outpatient knee arthroscopy.
The optimal anesthetic technique for outpatient knee arthroscopy remains controversial. In this study, we evaluated surgical operating conditions, patient satisfaction, recovery times, and postoperative analgesic requirements associated with psoas compartment block, general anesthetic, or spinal anesthetic techniques. Sixty patients were randomized to receive a propofol/nitrous oxide/fentanyl general anesthetic, spinal anesthesia with 6 mg of bupivacaine and 15 micro g of fentanyl, or psoas compartment block with 40 mL of 1.5% mepivacaine. All patients received IV ketorolac and intraarticular bupivacaine. The frequency of postanesthesia recovery room admission was 13 (65%) of 20 for patients receiving general anesthesia, compared with 0 of 21 for patients receiving spinal anesthesia and 1 (5%) of 19 for patients receiving psoas block (P < 0.001). The median time from the end of surgery to meeting hospital discharge criteria did not differ across groups (131, 129, and 110 min for general, spinal, and psoas groups, respectively). In the hospital, 45% of general anesthesia patients received opioid analgesics, compared with 14% of spinal anesthesia and 21% of psoas block patients (P = 0.087). There was no difference among groups with respect to the time of first analgesic use or the number of patients requiring opioid analgesia. Pain scores were highest in patients receiving general anesthesia at 30 min (P = 0.032) and at 60, 90, and 120 min (P < 0.001). Patient satisfaction with anesthetic technique (P = 0.025) and pain management (P = 0.009) differed significantly across groups; patients receiving general anesthesia reported lower satisfaction ratings. We conclude that spinal anesthesia or psoas block is superior to general anesthesia for knee arthroscopy when considering resource utilization, patient satisfaction, and postoperative analgesic management. ⋯ Outpatient knee arthroscopy may be performed using a variety of anesthetic techniques. We report that spinal anesthesia and psoas compartment block are superior to general anesthesia when considering resource utilization, patient satisfaction, and postoperative analgesic management.
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Anesthesia and analgesia · Oct 2003
Randomized Controlled Trial Clinical TrialSevoflurane requirements to suppress responses to transcutaneous electrical stimulation during epidural anesthesia with 0.5% and 1% lidocaine.
We sought to determine general anesthetic requirements to suppress skin vasomotor reflex (SVmR) and pupillary dilation (PD) in response to transcutaneous electrical stimulation (TES) during combined epidural-general anesthesia. Thirty-five patients undergoing lower abdominal surgery were randomly divided into 2 groups to epidurally receive 0.5% (Group 1) or 1% lidocaine (Group 2) with sevoflurane anesthesia. A bolus injection of either lidocaine was followed by the infusion of the same solution, and the central dermatomal level of loss of cold sensation (C) was determined. After the induction of general anesthesia with 5% sevoflurane and 67% nitrous oxide, nitrous oxide was discontinued, and sevoflurane concentration was decreased. TES was given at both site C and site three dermatomal segments (U) cephalad to C to determine the end-tidal sevoflurane concentration required to suppress SVmR and PD. End-tidal sevoflurane concentration that suppressed both responses was larger in Group 1 than in Group 2 at both sites and was larger at site U than at site C in both groups. We conclude that sevoflurane requirements to suppress SVmR and PD in response to TES during combined epidural-general anesthesia are different depending on the concentration of lidocaine and the site where surgical stimulation is applied. ⋯ We evaluated sevoflurane requirements to suppress skin vasomotor reflex and pupillary dilation in response to a transcutaneous electrical stimulation at the surgical site during combined epidural-general anesthesia. Our results indicate that when epidural anesthesia is combined, general anesthetic requirements decrease depending on the lidocaine concentration for epidural anesthesia and the site where surgical stimulation is applied.
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The authors present a rare case of a cervical cord dysfunction after uncomplicated coronary artery bypass grafting. The preoperative neurological examination did not reveal any abnormalities; however, the postoperative magnetic resonance image showed significant spinal canal stenosis at the same levels as high signal lesions. Although the pathophysiological basis of the case was impossible to determine retrospectively, it seems probable that placing the neck in an extended position during surgery might have aggravated a preexisting spinal canal stenosis to produce cervical injury. ⋯ The authors present a rare case of tetraplegia after coronary artery bypass grafting. It is suggested that neck extension during surgery might have aggravated an occult preexisting cervical spinal canal stenosis to produce cervical injury.