Anesthesia and analgesia
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Anesthesia and analgesia · Sep 1999
Randomized Controlled Trial Comparative Study Clinical TrialThe effectiveness of preemptive analgesia varies according to the type of surgery: a randomized, double-blind study.
The reliability of preemptive analgesia is controversial. Its effectiveness may vary among anatomical areas or surgical types. We evaluated preemptive analgesia by epidural morphine in six surgery types in a randomized, double-blind manner. Pain intensity was rated using a visual analog scale, a verbal report, and a measurement of postsurgical morphine consumption. Preemptive analgesia was effective in limb surgery and mastectomy, but ineffective for gastrectomy, hysterectomy, herniorrhaphy, and appendectomy. Relief of postsurgical pain in hemiorrhaphy was more rapid than that in the other surgery types. Preemptive analgesia was effective in limb surgery and mastectomy, but not in surgeries involving laparotomy, regardless of whether the surgery was major (gastrectomy and hysterectomy) or minor (herniorrhaphy and appendectomy). These results suggest that viscero-peritoneal nociception is involved in postsurgical pain. The abdominal viscera and peritoneum are innervated both heterosegmentally (in duplicate or triplicate by the vagus and/or phrenic nerves) and segmentally (by the spinal nerves). Therefore, supraspinal and/or cervical spinal neurons might be sensitized, despite the blockade of the segmental nerves with epidural morphine. The rapid retreat of the pain after hemiorrhaphy suggests that central sensitization remits soon after minor surgery, but that in appendicitis, it may be protracted by additional noxious stimuli, such as infection. ⋯ Epidural preemptive analgesia was reliably effective in limb and breast surgeries but ineffective in abdominal surgery, suggesting involvement of the brainstem and cervical spinal cord via the vagus and phlenic nerves.
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Anesthesia and analgesia · Sep 1999
Randomized Controlled Trial Comparative Study Clinical TrialThe effects of antagonizing residual neuromuscular blockade by neostigmine and glycopyrrolate on nausea and vomiting after ambulatory surgery.
The effects of neostigmine on the incidence of postoperative nausea and vomiting (PONV) are controversial. In this study, we evaluated the effects of neostigmine and glycopyrrolate on the incidence of PONV and the need for antiemetics in patients undergoing ambulatory surgery. One hundred healthy patients undergoing outpatient surgical procedures were included in the study. A standardized anesthetic technique was used for all patients. Patients were randomized to receive either mivacurium (n = 50) or rocuronium (n = 50) to achieve muscle paralysis. Bolus doses of mivacurium 2-4 mg or rocuronium 5-10 mg were administered to maintain one or two twitches of the train-of-four stimulation of the ulnar nerve at the wrist. After surgery, residual neuromuscular blockade was reversed with neostigmine 2.5 mg i.v. and glycopyrrolate 0.5 mg i.v. only if clinically deemed necessary (i.e., fade on train-of-four stimulation, inadequate tidal volume, reduced hand grip, or inability to maintain head lift). The incidence of PONV and the need for antiemetics were recorded in the post-anesthesia care unit (PACU), in the phase II unit, and 24 h after surgery. We compared patients who received neostigmine (n = 40) for reversal of residual neuromuscular blockade with those who did not (n = 60). More patients receiving rocuronium required reversal drugs than those receiving mivacurium (68% vs 10%). There were no differences in the incidence of nausea (18% vs 15%), vomiting (8% vs 12%), and the need for antiemetics (13% in both the groups) in the PACU between patients who received neostigmine and those who did not. In addition, the duration of PACU stay and the time to home-readiness were also similar between the groups. We conclude that, compared with rocuronium, the use of mivacurium decreases the need for reversal drugs. In addition, reversal of residual neuromuscular blockade with neostigmine does not increase the incidence of PONV or the need for antiemetic medications in patients undergoing ambulatory surgery. ⋯ In this study, we showed that the incidence of postoperative nausea and vomiting and the need for antiemetics do not increase with the use of neostigmine and glycopyrrolate for reversal of residual muscle paralysis.
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Anesthesia and analgesia · Sep 1999
Clinical Trial Controlled Clinical TrialThe preoperative administration of intravenous dextromethorphan reduces postoperative morphine consumption.
We evaluated the effect of dextromethorphan on postoperative pain management. Sixty ASA physical status I-III female patients undergoing major abdominal surgery underwent standardized general anesthesia. Thirty patients received an i.v. infusion of dextromethorphan 5 mg/kg before anesthetic induction (Pre group), whereas the remaining 30 patients received the same volume of isotonic sodium chloride solution, followed by a postoperative i.v. infusion of dextromethorphan 5 mg/kg (Post group). Patients in the Pre group received the same volume of isotonic sodium chloride solution postoperatively. All patients were then treated with patient-controlled i.v. analgesia, which administered a 0.6-mg bolus of morphine on demand (maximal 4 h dose 20 mg). The mean visual analog pain score during cough or movement and at rest were similar in the two groups in the first 3 days postoperatively. However, Post group patients consumed more morphine than Pre group patients during the first 2 days (P < 0.01). The sedation scores, patient satisfaction, and the incidence of morphine-related side effects were similar between the two groups. We conclude that the preoperative administration of dextromethorphan 5 mg/kg reduces postoperative morphine consumption compared with postoperative administration. ⋯ In this double-blinded study, we found that the preoperative administration of i.v. dextromethorphan 5 mg/kg, compared with postoperative administration, reduces postoperative morphine consumption, which may provide clinical evidence of preemptive or preventive analgesic effects of dextromethorphan.
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Anesthesia and analgesia · Sep 1999
Randomized Controlled Trial Clinical TrialFentanyl pretreatment does not impair the reliability of an epinephrine-containing test dose during propofol-nitrous oxide anesthesia.
We designed this study to determine the hemodynamic responses to and the efficacy of a simulated IV test dose during propofol anesthesia based on the conventional heart rate (HR; positive if increase > or =20 bpm), the modified HR (positive if increase > or =10 bpm), and the systolic blood pressure (SBP; positive if increase > or =15 mm Hg) criteria. Eighty healthy patients were randomized to receive 2 mg/kgpropofol or propofol plus fentanyl (100 microg) at the induction of anesthesia (n = 40 each). After endotracheal intubation, anesthesia in both groups was maintained with propofol 8 mg x kg(-1) x h(-1) and 67% nitrous oxide in oxygen. Each group of patients was further divided into a test dose group receiving 1.5% lidocaine 3 mL plus epinephrine 15 microg (1:200,000) or a saline group (n = 20 each) receiving 3 mL of isotonic sodium chloride solution i.v. HR and SBP were monitored for 4 min after the i.v. injection of the study drug. The i.v. injection of the test dose produced a HR increase > or =20 bpm in 20 and 17 patients in the propofol and propofol-fentanyl groups, respectively, whereas all patients receiving the test dose and none receiving saline had HR increases > or =10 bpm. Therefore, in the propofol-fentanyl group, sensitivity, specificity, positive predictive value, and negative predictive value were 85%, 100%, 100%, and 87% according to the conventional HR criterion, and all were 100% according to the modified HR criterion. In the propofol group, 100% efficacy was obtained based on both HR criteria. However, all patients receiving the test dose and none receiving saline developed a SBP increase > or =15 mm Hg, resulting in 100% efficacy based on the conventional SBP criterion in both groups. Our results indicate that both the modified HR criterion and the SBP criterion are clinically applicable during propofol anesthesia with or without supplemental fentanyl. ⋯ To determine whether an epidural catheter is in a blood vessel, an epidural test dose containing 15 microg of epinephrine is used. We found that, during propofol anesthesia with or without fentanyl, a heart rate increase > or =10 bpm and a systolic blood pressure increase > or =15 mm Hg are reliable indicators for detecting accidental intravascular injection.
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Anesthesia and analgesia · Sep 1999
Randomized Controlled Trial Comparative Study Clinical TrialComparison of vital capacity induction with sevoflurane to intravenous induction with propofol for adult ambulatory anesthesia.
We compared vital capacity inhaled induction (VC) with sevoflurane with i.v. induction with propofol for adult ambulatory anesthesia. Patients were randomly assigned to receive either 8% sevoflurane in 75% N2O/O2 from a primed circuit (VC, 32 patients) or propofol 2-mg/kg bolus (i.v., 24 patients). Times to loss of consciousness (response to command) and induction side effects (airway, hemodynamic, motor) were assessed. Anesthesia was maintained with sevoflurane/N2O via a face mask for both groups. At the end of surgery, recovery times were measured and psychomotor function tests were performed. Patients were also asked to assess the quality of their anesthesia. Of the VC patients, 59% lost responsiveness in one breath, taking 39 +/- 3 s. All VC patients completed the induction, and all measures of induction time were significantly shorter for VC than for i.v. Induction side effects were different in the two groups (cough and hiccough for VC versus movement and blood pressure changes for i.v.), but overall incidences were similar. There were no significant differences in any index of early or intermediate recovery. Mild nausea occurred more often with VC, but no antiemetics were needed, and discharge was not delayed. Patients' assessments of the quality of induction or wake up were not significantly different between VC and i.v. Thus, VC induction with sevoflurane is an acceptable alternative to propofol i.v. induction of general anesthesia for adult ambulatory surgical patients. ⋯ A vital capacity induction with sevoflurane produced a faster loss of consciousness and had side effects, recovery times, and patient satisfaction similar to that of a propofol induction in adults undergoing ambulatory surgery.