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BackgroundSerotonin-also known as 5-hydroxytryptamine or 5-HT-can induce nausea and vomiting (NV) by peripheral mechanisms via the activation of 5-HT3 receptors. In this study, we observed perioperative NV, including intraoperative NV, and changes in serum 5-HT concentrations. We evaluated the relationship between perioperative NV and serum 5-HT levels in patients undergoing cesarean section under epidural anesthesia, and carried out a pilot study to determine if further studies on a larger scale were justified.MethodsTwenty-eight patients who were scheduled for cesarean section under epidural anesthesia were included in the study. Patients were assigned to 2 groups according to the occurrence of NV after induction, i.e., an NV-positive or an NV-negative group. Serum 5-HT concentrations were measured before induction, at the time that NV occurred (in the case of the NV-positive group) or 5 min after the umbilical cord clamping (in the case of the NV-negative group) during surgery, and at 2 h postoperatively.ResultsNV occurred in 10 of the 28 patients. No significant differences in serum 5-HT concentrations were found within or between the two groups.ConclusionsThis study suggests that there is no correlation between serum 5-HT concentration and the occurrence of perioperative NV in patients undergoing cesarean section under epidural anesthesia, and the findings do not seem to support further investigations regarding a possible relationship between serum 5-HT concentration and perioperative NV.

BackgroundSevoflurane and propofol are used widely for interventional neuroradiology (INR). Using the bispectral index (BIS), we compared the clinical properties of sevoflurane and propofol anesthesia in patients undergoing INR at comparable depths of anesthesia.MethodsThe patients were allocated randomly into two groups. The sevoflurane group received propofol (1.5 mg/kg), alfentanil (5 µg/kg), and rocuronium (0.6 mg/kg) for induction, and the propofol group was induced with a target effect-site concentration of propofol (4 µg/ml), alfentanil (5 µg/kg), and rocuronium (0.6 mg/kg). After intubation, anesthesia was maintained with sevoflurane or propofol with 67% nitrous oxide in 33% oxygen. Sevoflurane and propofol concentrations were titrated to maintain the BIS at 50-60. Phenylephrine or opioid was used to maintain the mean arterial pressure within 20% of the baseline values. The amounts of phenylephrine or alfentanil used, the number of patients showing movement during the procedure, and the recovery times were recorded.Results Compared to the propofol group, the sevoflurane group showed faster recovery in spontaneous ventilation, eye opening, extubation, and orientation (4 vs. 7 min, 7 vs. 9 min, 8 vs. 10 min, 10 vs. 14 min, respectively; P < 0.01). In the propofol group, significantly greater amounts phenylephrine were used (P < 0.05), and more patients moved during the procedure (P < 0.05).ConclusionsThe use of sevoflurane in maintaining anesthesia during INR was associated with faster recovery, less patient movement during the procedure, and a more stable hemodynamic response when compared to propofol.

BackgroundRapid and complete reversal of neuromuscular blockade (NMB) is desirable at the end of surgery. Sugammadex reverses rocuronium-induced NMB by encapsulation. It is well tolerated in Caucasian patients, providing rapid reversal of moderate (reappearance of T2) rocuronium-induced NMB. We investigated the efficacy and safety of sugammadex versus neostigmine in Korean patients.MethodsThis randomized, safety assessor-blinded trial (NCT01050543) included Korean patients undergoing general anesthesia. Rocuronium 0.6 mg/kg was given prior to intubation with maintenance doses of 0.1-0.2 mg/kg as required. Patients received sugammadex 2.0 mg/kg or neostigmine 50 µg/kg with glycopyrrolate 10 µg/kg to reverse the NMB at the reappearance of T2, after the last rocuronium dose. The primary efficacy endpoint was the time from sugammadex or neostigmine administration to recovery of the train-of-four (TOF) ratio to 0.9. The safety of these medications was also assessed.ResultsOf 128 randomized patients, 118 had evaluable data (n = 59 in each group). The geometric mean (95% confidence interval) time to recovery of the TOF ratio to 0.9 was 1.8 (1.6, 2.0) minutes in the sugammadex group and 14.8 (12.4, 17.6) minutes in the neostigmine group (P < 0.0001). Sugammadex was generally well tolerated, with no evidence of residual or recurrence of NMB; four patients in the neostigmine group reported adverse events possibly indicative of inadequate NMB reversal.ConclusionsSugammadex was well tolerated and provided rapid reversal of moderate rocuronium-induced NMB in Korean patients, with a recovery time 8.1 times faster than neostigmine. These results are consistent with those reported for Caucasian patients.

BackgroundThe purpose of this study was to measure lumbar epidural pressure (EP) during the insertion of a Tuohy needle under general anesthesia and to evaluate the influence of airway pressure on EP.MethodsLumbar EP was measured directly through a Tuohy needle during intermittent positive pressure ventilation in fifteen patients. Mean and peak EP were recorded after peak inspiratory pressures (PIP) of 0, 15, and 25 cmH2O.ResultsAll measured lumbar EPs were positive, with the pressure increasing during inspiration and decreasing during expiration. Median EP was 6.0 mmHg (interquartile range, 4.0-8.0) at 0 cmH2O of PIP, 6.5 mmHg (4.5-8.5) at 15 cmH2O, and 8.5 mmHg (6.0-10.5) at 25 cmH2O, increasing significantly at 15 cm H2O PIP, and further increasing at 25 cmH2O (P < 0.001).ConclusionsWe demonstrate the influence of increased airway pressure on lumbar EP measured directly through a Tuohy needle. Lumbar EPs were positive, and increasing PIP levels significantly increased lumbar EP.

BackgroundNeck flexion has been shown to increase cranial spread of contrast agent when a small fixed volume was injected into the high thoracic epidural space. The purpose of this study was to evaluate the effect of volume of contrast medium on its distribution through the high thoracic epidural space during neck extension and flexion using the rabbit model.MethodsAn epidural catheter was introduced into the epidural space of New Zealand white rabbits with the tip located at the T3-4 intervertebral level. The neck was extended or flexed (n = 8 for each group), and the contrast medium was injected with the volume increasing by increments of 0.1 ml/kg, up to 0.3 ml/kg. The spread of contrast medium was determined by counting the number of vertebral body units using lateral epidurographic images.ResultsIn both groups, the total spread of contrast medium was similar, increasing continuously with injected volume. The cranial spread was greater in the flexion group than the extension group. However, the caudal spread was greater in the extension than in the flexion group. In the extension group, the contrast medium spread caudally about twice as far as it spread cranially, but there was no statistically significant difference between cranial and caudal spread in the flexion group.ConclusionsIn the high thoracic epidural space of rabbit, the contrast medium of varying doses showed limited cranial spread. The flexion of the neck increased cranial spread and extension of the neck increased caudal spread.

BackgroundWe hypothesized that, even in patients taking aspirin, the variance of preoperative platelet response to collagen might be associated with myocardial injury during coronary artery bypass graft (CABG) surgery. Therefore, we evaluated the relationship between preoperative whole-blood aggregometry (WBA) by collagen and the postoperative myocardial injuries.MethodsFor 44 patients who were scheduled for elective off-pump CABG and taking aspirin, WBA was measured by the impedance method in the presence of collagen (2 mg/ml or 5 mg/ml) as stimulatory agents. After CABG, myocardial injury was evaluated by analysis of the creatine kinase (CK), creatine kinase-MB (CK-MB), and lactate dehydrogenase (LD), and by electrocardiography.ResultsHigh response group (n = 13) on preoperative WBA with collagen (2 and 5 mg/ml) showed significantly higher postoperative cardiac enzyme levels (CK, CK-MB and LD) than those of low response group (n = 31).ConclusionsIn patients who take aspirin and undergoing off-pump CABG, the preoperative platelet response to collagen is correlated with postoperative myocardial injury.

BackgroundThe aim of this study was to investigate the neuroprotective effects of sevoflurane after severe forebrain ischemic injury. We also examined the relationship between the duration of ischemia and neuronal cell death.MethodsMale Sprague-Dawley rats (300-380 g) were subjected to 6 (each n = 6) or 10 min (each n = 10) of near-complete forebrain ischemia while anesthetized with either 50 mg/kg of zoletil given intraperitoneally or inhaled sevoflurane (2.3%). Ischemia was induced by bilateral common carotid artery occlusion plus hemorrhagic hypotension (26-30 mmHg). Histologic outcomes were measured 7 days after ischemia in CA1 pyramidal cells of the rat hippocampus.ResultsThe mean percentage of necrotic cells in the hippocampal CA1 area decreased in the sevoflurane group compared to the zoletil group (25% vs. 40% after 6 min ischemia, respectively: P = 0.004 and 44% vs. 54% after 10 min of ischemia, respectively P = 0.03). The percentage of apoptotic cells was similar in all groups. The percentage of necrotic cells in each anesthetic groups was significantly higher in the 10 min ischemia group compared to the 6 min ischemia group (P = 0.004 in the sevoflurane group, P = 0.03 in the zoletil group).ConclusionsThe present data show that sevoflurane has neuroprotective effects in rats subjected to near-complete cerebral ischemia. Longer duration of ischemia is associated with more neuronal injury when compared to ischemia of shorter duration.

BackgroundThis randomized controlled study evaluated the efficacy of intravenous patient-controlled analgesia (IV-PCA) with fentanyl and ketorolac for neurosurgical patients, and compared the effectiveness of IV-PCA with intermittent analgesics injection.MethodsThe patients undergoing craniotomy were randomly assigned to two groups. Patients of group P (n = 53) received fentanyl (0.2 µg/kg/hr) and ketorolac (0.3 mg/kg/hr) via IV-PCA, and those of group N (n = 53) received intermittent fentanyl or ketorolac injection as needed. Pain was evaluated using a 0-10 visual analogue scale (VAS) at postoperative 1, 4, and 24 hr. The amount of infused analgesic drugs, Glasgow Coma Scale (GCS) score, systolic arterial pressure, heart rate, respiratory rate, and the incidence of nausea and miosis were measured at the same time points.ResultsAlthough VAS of pain (VASp) was comparable at postoperative 1 hr (P = 0.168) between the two groups, the group P had significantly lower VASp at postoperative 4 hr (P = 0.007) and 24 hr (P = 0.017). In group P, less analgesic drugs were administered at postoperative 1 hr, and more analgesic drugs were administered at postoperative 24 hr. There were no differences between two groups with respect to nausea, GCS, systolic arterial pressure, and heart rate. IV-PCA did not further incur respiratory depression or miosis.ConclusionsIV-PCA with fentanyl and ketorolac after craniotomy is more effective analgesic technique, without adverse events, than the intermittent administration of analgesics.