Effects of epidural anesthesia on postoperative nausea and vomiting in laparoscopic gynecological surgery: a randomized controlled trial.

PURPOSE: Patients undergoing laparoscopic gynecological surgery are susceptible to postoperative nausea and vomiting (PONV). We hypothesized that a combination of epidural and general anesthesia to minimize intraoperative opioid administration would reduce the incidence of PONV following laparoscopic gynecological surgery. METHODS: Women undergoing elective laparoscopic gynecological surgery were randomly assigned to receive general anesthesia alone (group G, n = 45) or general anesthesia with epidural anesthesia (group GE, n = 45). Patients in group G received fentanyl and remifentanil for intraoperative analgesia, and those in group GE received single-shot ropivacaine at the time of induction of anesthesia. The primary outcome was the incidence of PONV within 24 h of surgery. Secondary outcomes included the use of rescue metoclopramide within 24 h of surgery and the time to first incidence of PONV and first use of rescue metoclopramide. RESULTS: The incidence of PONV within 24 h of surgery was 60.0% in group G and 44.4% in group GE [relative risk (RR): 0.53, 95% confidence interval (CI): 0.23-1.23, p = 0.14]. There were no intergroup differences in the use of rescue metoclopramide (40.0% in group G, 24.4% in group GE, RR: 0.49, 95% CI 0.20-1.20, p = 0.11) and the time to first incidence of PONV and first use of rescue metoclopramide (p = 0.20 and 0.12, respectively). CONCLUSION: Minimizing intraoperative opioid administration by combining epidural and general anesthesia did not reduce the 24-h incidence of PONV or rescue metoclopramide use after laparoscopic gynecological surgery.

Reversal with sugammadex in the absence of monitoring did not preclude residual neuromuscular block.

BACKGROUND: In Japan, routine clinical care does not normally involve the use of a monitoring device to guide the administration of neuromuscular blocking drugs or their antagonists. Although most previous reports demonstrate that sugammadex offers more rapid and reliable antagonism from rocuronium-induced neuromuscular blockade, this advantage has not been confirmed in clinical settings when no neuromuscular monitoring is used. In this multicenter observational study, we sought to determine whether sugammadex reduces the incidence of postoperative residual weakness compared with neostigmine when the administration of rocuronium and its antagonists is not guided by neuromuscular monitoring. METHODS: This study was conducted in two 5-month periods that preceded and followed the introduction of sugammadex into clinical practice in Japan. Five university-affiliated teaching hospitals participated in this study. Neostigmine was used to antagonize rocuronium-induced neuromuscular blockade in the first phase, and sugammadex was used in the second phase. The timing and doses of rocuronium, neostigmine, and sugammadex were determined by the attending anesthesiologists without the use of neuromuscular function monitoring devices. To ascertain the incidence of postoperative residual neuromuscular weakness, the train-of-four ratio (TOFR) was determined acceleromyographically after tracheal extubation. Since our practice also does not usually involve calibration and normalization of accelerographic responses, both TOFR <0.9 and TOFR <1.0 were used as the criteria for defining postoperative residual weakness. RESULTS: In the first phase, 109 patients received neostigmine (average dose 33 µg/kg) and 23 patients were considered (by clinical criteria) to have adequate recovery and did not receive neostigmine (spontaneous recovery group). In the second phase, 117 patients received sugammadex (average dose 2.7 mg/kg) for antagonism of rocuronium-induced blockade. The incidence (95% confidence interval) of TOFR <0.9 under spontaneous recovery, after neostigmine, and after sugammadex, was 13.0% (2.8%-33.6%), 23.9% (16.2%-33.0%), and 4.3% (1.7%-9.4%), respectively. The incidence (95% confidence interval) of TOFR <1.0 in these groups was 69.6% (47.1%-86.6%), 67.0% (57.3%-75.7%), and 46.2% (36.9%-55.6%), respectively. The use of sevoflurane in the neostigmine group and the short interval between the administration of the last doses of rocuronium and sugammadex were associated with a higher incidence of postoperative residual weakness. CONCLUSIONS: This study demonstrated that the risk of TOFR <0.9 after tracheal extubation after sugammadex remains as high as 9.4% in a clinical setting in which neuromuscular monitoring (objective or subjective) was not used. Our finding underscores the importance of neuromuscular monitoring even when sugammadex is used for antagonism of rocuronium-induced neuromuscular block.

Retrospective evaluation of intravenous fentanyl patient-controlled analgesia during labor.

PURPOSE: Because the safety of intravenous fentanyl patient-controlled analgesia (iv-PCA) administered during labor remains unclear, we retrospectively examined the labor records from January 2005 to December 2007 in our institution, with a focus on both maternal and neonatal outcomes, as compared to no analgesia. METHODS: Parturients over 35 weeks of gestational age who received fentanyl iv-PCA (iv-PCA group) or no analgesia (control group) during labor were enrolled. The former group received iv-PCA through a pump programmed to give a loading dose of 0.05 mg fentanyl, followed by bolus injection of 0.02 mg fentanyl, with a lock-out interval of 5 min. This analgesia was initiated at the parturient's request and was discontinued before the second stage of labor, to ensure neonatal safety. During labor, both maternal and fetal heart rates, maternal pulse oximeter oxygen saturation (SpO(2)), respiratory rate, and sedation and nausea scores were continuously monitored, and the neonatal outcomes including umbilical arterial pH, Apgar scores, and other parameters were recorded. RESULTS: The data of 129 of the 143 parturients who received fentanyl iv-PCA were analyzed, while 697 parturients delivered without any analgesia during the 3-year study period. While iv-PCA prolonged the duration of labor and increased oxytocin use, no obvious maternal or neonatal complications of fentanyl use were recorded. Except for the significantly lower rate of emergency cesarean section in the iv-PCA group, both the maternal and neonatal outcomes were comparable between the groups. CONCLUSIONS: As compared to no analgesia, fentanyl iv-PCA appears to be safe and clinically acceptable as analgesia during labor, particularly in nulliparous women.

[Dibucaine for spinal anesthesia is a probable risk for cauda equina syndrome].

A 64-year-old man was scheduled for transure thral resection of the prostate. The patient's medical history showed borderline diabetic state and two uncomplicated surgeries under spinal anesthesia. Spinal anesthesia was performed at the L 3/4 interspace using hyperbaric 0.24% dibucaine 2.2 ml, which was followed by general anesthesia because the anesthesia level had spread only to the lower left side of the body. On the next day, he complained of difficulty of defecation and urination combined with hypesthesia around the anus, which was diagnosed as cauda equina syndrome. The symptoms had not changed for three weeks. Then, there was a gradual recovery but slight hypesthesia remained even four months after the surgery. Speculation of this clinical etiology suggests that high concentration of dibucaine, having maldistributed inside the intrathecal space, affected cauda equina, which resulted in irreversible nerve damage. There were other risk factors for cauda equina syndrome in this patient such as lithotomy position, history of frequent spinal anesthesia, diabetes and advanced age. None of these are contraindication for spinal anesthesia. Many elderly patients particularly undergoing urological surgeries are likely to have such risk factors. Therefore at least dibucaine should be avoided for spinal anesthesia because of its high neurotoxicity compared with other local anesthetics.

Changes in heart rate variability in sevoflurane and nitrous oxide anesthesia: effects of respiration and depth of anesthesia.

STUDY OBJECTIVE: To quantify the effects of sevoflurane on autonomic nerve function by analyzing changes in heart rate (HR) variability in sevoflurane anesthesia; and to investigate the effects of anesthetic depth and apnea on HR variability. DESIGN: Prospective study. SETTING: Operating room (OR) of a university medical center. PATIENTS: 7 ASA physical status I and II patients scheduled for elective surgery. INTERVENTIONS: Patients were premedicated with ranitidine 150 mg. Anesthesia was induced with thiopental sodium 4 mg/kg intravenously (IV) and succinylcholine 1 mg/kg IV, and maintained with nitrous oxide (N(2)O) 67% and sevoflurane in oxygen. Patients were ventilated mechanically at a rate of 15 breaths/min. MEASUREMENTS: R-R interval of electrocardiography (ECG), electroencephalogram (EEG), noninvasive arterial blood pressure (BP), and end-tidal sevoflurane concentration were recorded. Measurements were performed 1) after patients arrived at the OR and were placed in the supine position, 2) a stable period after inhalation of 2% sevoflurane, and 3) following the appearance of an isoelectric EEG at a higher concentration of sevoflurane. At times 2) and 3), data were recorded during mechanical ventilation and during apnea. MAIN RESULTS: There were decreases in both the low-frequency (LF; 0.04 to 0.15 Hz) and high-frequency (HF; 0.15 to 0.4 Hz) components of HR variability during anesthesia compared with the awake state. HF decreased during apnea at 2% sevoflurane, but LF did not change. Neither LF nor HF changed in response to the absence or presence of respiration during isoelectric EEG. CONCLUSIONS: Autonomic nerve activity was attenuated by sevoflurane. Parasympathetic input to the heart by respiration was markedly suppressed following the appearance of isoelectric EEG.