Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2002
Randomized Controlled Trial Clinical TrialThe effect of methylene blue on the hemodynamic changes during ischemia reperfusion injury in orthotopic liver transplantation.
After graft reperfusion in orthotopic liver transplantation (OLT), ischemia reperfusion syndrome (IRS) is characterized by persistent hypotension with a low systemic vascular resistance. Methylene blue (MB) has been used as a vasopressor in sepsis and acute liver failure. We investigated the effect of MB on IRS during OLT. Thirty-six patients undergoing elective OLT were randomized to receive either a bolus of MB 1.5 mg/kg before graft reperfusion, or normal saline (placebo). We recorded hemodynamic variables, postoperative liver function tests, and time to hospital discharge. Blood samples were analyzed for arterial lactate concentration, cyclic 3',5'-monophosphate, and plasma nitrite/nitrate concentrations. The MB group had higher mean arterial pressure (P = 0.035), higher cardiac index (P = 0.04), and less epinephrine requirement (P = 0.02). There was no difference in systemic vascular resistance or central venous pressure. Serum lactate levels were lower at 1 h after reperfusion in MB patients, suggesting better tissue perfusion (P = 0.03). In the presence of MB, there was a reduction in cyclic 3',5'-monophosphate (P < 0.001), but not plasma nitrites. Postoperative liver function tests and time to hospital discharge were the same in both groups. MB attenuated the hemodynamic changes of IRS in OLT acting via guanylate cyclase inhibition. ⋯ Methylene blue attenuates the hemodynamic changes of the ischemia reperfusion syndrome in liver transplantation, and this effect involves guanylate cyclase inhibition.
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Anesthesia and analgesia · Apr 2002
Randomized Controlled Trial Clinical TrialKorean hand acupressure reduces postoperative nausea and vomiting after gynecological laparoscopic surgery.
To investigate the effectiveness of prophylactic Korean hand acupressure in the prevention of postoperative vomiting in women scheduled for minor gynecological laparoscopic surgery, we conducted a double-blinded, randomized, placebo-controlled study. In one group (n = 40), acupressure was performed 30 min before the induction of anesthesia by using special acupressure seeds, which were fixed onto the Korean hand acupuncture point K-K9 and remained there for at least 24 h. The second group (n = 40) functioned as the Placebo group. The treatment groups did not differ with regard to demographics, surgical procedure, or anesthetic administered. In the Acupressure group, the incidence of nausea and vomiting was significantly less (40% and 22.5%) than in the Placebo group (70% and 50%). We conclude that Korean hand acupressure of the acupuncture point K-K9 is an effective method for reducing postoperative nausea and vomiting in women after minor gynecological laparoscopic surgery. ⋯ This randomized study was performed to investigate the antiemetic effect of the Korean hand acupuncture point K-K9. Acupressure of K-K9 reduces the incidence of postoperative nausea and vomiting in female patients after minor gynecological laparoscopic surgery.
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Anesthesia and analgesia · Apr 2002
Randomized Controlled Trial Clinical TrialPostoperative analgesia with continuous sciatic nerve block after foot surgery: a prospective, randomized comparison between the popliteal and subgluteal approaches.
To compare the posterior popliteal and subgluteal continuous sciatic nerve block for anesthesia and acute postoperative pain management after foot surgery, 60 ASA physical status I and II patients undergoing elective orthopedic foot surgery were randomly assigned to either a Subgluteal group (n = 30) or Popliteal group (n = 30). Before surgery and after performing a femoral nerve block with 15 mL of 2% mepivacaine, we performed the sciatic nerve block with 20 mL of 0.75% ropivacaine using either a subgluteal or posterior popliteal approach, and the placement of a catheter came afterward. In the recovery room, the catheter was connected to a patient-controlled analgesia pump to infuse 0.2% ropivacaine (basal infusion rate of 5 mL/h, incremental bolus of 10 mL, and a lockout time of 60 min). There were no technical problems in catheter placement. Intraoperative efficacy of nerve block was similar in the two groups. Postoperative catheter displacement and occlusion were recorded in four patients in the Popliteal group and two patients in the Subgluteal group (P = 0.67). Both approaches provided similar postoperative analgesia. We conclude that the subgluteal approach is as effective and safe as the previously described posterior popliteal approach for continuous sciatic block and can be considered a useful alternative to anesthesia and acute postoperative analgesia after foot procedures. ⋯ Comparing two different approaches for continuous sciatic nerve block after orthopedic foot surgery, this prospective, randomized study demonstrated that the subgluteal approach is as effective and safe as the previously described posterior popliteal approach, and can be considered a useful alternative to anesthesia and acute postoperative analgesia after foot procedures.
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Anesthesia and analgesia · Apr 2002
How to schedule elective surgical cases into specific operating rooms to maximize the efficiency of use of operating room time.
We considered elective case scheduling at hospitals and surgical centers at which surgeons and patients choose the day of surgery, cases are not turned away, and anesthesia and nursing staffing are adjusted to maximize the efficiency of use of operating room (OR) time. We investigated scheduling a new case into an OR by using two patient-scheduling rules: Earliest Start Time or Latest Start Time. By using several scenarios, we showed that the use of Earliest Start Time is rational economically at such facilities. Specifically, it maximizes OR efficiency when a service has nearly filled its regularly scheduled hours of OR time. However, Latest Start Time will perform better at balancing workload among services' OR time. We then used historical case duration data from two facilities in computer simulations to investigate the effect of errors in predicting case durations on the performance of these two heuristics. The achievable incremental reduction in overtime by having perfect information on case duration versus using historical case durations was only a few minutes per OR. The differences between Earliest Start Time and Latest Start Time were also only a few minutes per OR. We conclude that for facilities at which the goals are, in order of importance, safety, patient and surgeon access to OR time, and then efficiency, few restrictions need to be placed on patient scheduling to achieve an efficient use of OR time. ⋯ We showed how elective cases should be scheduled to maximize the efficiency of use of operating room time. The analysis applies to surgical suites at which surgeons and patients have access to operating room time every workday.
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Anesthesia and analgesia · Apr 2002
Clinical TrialRemifentanil in obstetric analgesia: a dose-finding study.
IV patient-controlled analgesia (PCA) with remifentanil is a new approach in systemic opioid analgesia during labor. We determined the minimum effective dose of IV remifentanil by increasing the PCA bolus from 0.2 microg/kg with 0.2 microg/kg increments during a 60-min study period until the analgesia was considered adequate by the parturient. Twenty healthy parturients with singleton pregnancies participated in the study during the first stage of labor. Remifentanil hydrochloride was given IV via PCA over 1 min with a lockout time of 1 min. The parturient started the PCA bolus at the first subjective sign of uterine contraction. All 17 patients who completed the study reached adequate pain relief. The median effective PCA bolus was 0.4 microg/kg and consumption was 0.066 microg x kg(-1) x min(-1), with wide individual variation (0.2-0.8 microg/kg and 0.027-0.207 microg x kg(-1) x min(-1), respectively). The pain scores were reduced by a median of 4.2 (25th-75th percentiles, 3.1-5.2; P < 0.001) on an 11-point numeric scale. Although there was a wide individual variation in the dose required, remifentanil seems effective for labor analgesia. However, maternal oxygen desaturation, sedation, and reduced fetal heart rate beat-to-beat variability were observed frequently. There was wide individual variation in the dose required for effective labor analgesia. Potentially serious side effects, which were observed frequently during remifentanil analgesia, may limit remifentanil's use in obstetrics. ⋯ We determined the minimum effective dose of patient-controlled IV remifentanil for labor analgesia. There was wide individual variation in the dose required for effective labor analgesia. Potentially serious side effects, which were observed frequently during remifentanil analgesia, may limit its use in obstetrics.