Quantification of glutathione in plasma samples by HPLC using 4-fluoro-7-nitrobenzofurazan as a fluorescent labeling reagent.

A rapid and highly sensitive high-performance liquid chromatograpy method with fluorescence detection has been developed for determination of glutathione (GSH) in human plasma. A simple pre-column derivatization procedure with 7-flouro-4-nitrobenzo-2-oxa-1,3-diazole (NBD-F) reagent was employed. The separation of the derivatized glutathione was performed using a mobile phase consisting of phosphate buffer (0.02 mol/L, pH 6.0)-acetonitrile (77:23, v/v) at a flow rate of 1.0 mL/min with the column temperature 2°C. The eluted derivatives were fluorometrically detected at an excitation wavelength 470 nm and an emission wavelength 530 nm. Under the optimum chromatographic conditions, the calibration curve was linear over the range of 0.1 µmol/L to 10.0 µmol/L with the correlation coefficient of 0.9988. The precision of the method was satisfactory with the intra- and inter-day coefficient of variation being 6.3%, 6.9%, respectively. This method has been used to determine glutathione concentrations in plasma samples from healthy individuals.

Transdermal scopolamine: an alternative to ondansetron and droperidol for the prevention of postoperative and postdischarge emetic symptoms.

BACKGROUND: Given the controversy regarding the use of droperidol and the high cost of the 5-HT3 antagonists, a cost-effective alternative for routine use as a prophylactic antiemetic would be desirable. We designed two parallel, randomized, double-blind sham and placebo-controlled studies to compare the early and late antiemetic efficacy and adverse event profile of transdermal scopolamine (TDS) 1.5 mg, to ondansetron 4 mg IV, and droperidol 1.25 mg IV for antiemetic prophylaxis as part of a multimodal regimen in "at risk" surgical populations. METHODS: A total of 150 patients undergoing major laparoscopic (n = 80) or plastic (n = 70) surgery procedures received either an active TDS patch (containing scopolamine 1.5 mg) or a similar appearing sham patch 60 min before entering the operating room. All patients received a standardized general anesthetic technique. A second study medication was administered in a 2-mL numbered syringe containing either saline (for the two active TDS groups), droperidol, 1.25 mg, or ondansetron, 4 mg (for the sham patch groups), and was administered IV near the end of the procedure. The occurrence of postoperative nausea and vomiting/retching, need for rescue antiemetics, and the complete response rates (i.e., absence of protracted nausea or repeated episodes of emesis requiring antiemetic rescue medication) was reported. In addition, complaints of visual disturbances, dry mouth, drowsiness, and restlessness were noted up to 72 h after surgery. RESULTS: There were no significant differences in any of the emetic outcomes or need for rescue antiemetics among the TDS, droperidol, and ondansetron groups in the first 72 h after surgery. The complete response rates varied from 41% to 51%, and did not significantly differ among the treatment groups. The overall incidence of dry mouth was significantly more frequent in the TDS groups than in the droperidol and ondansetron groups (21% vs 3%). CONCLUSIONS: Premedication with TDS was as effective as droperidol (1.25 mg) or ondansetron (4 mg) in preventing nausea and vomiting in the early and late postoperative periods. However, the use of a TDS patch is more likely to produce a dry mouth.

Effect of low-dose droperidol on the QT interval during and after general anesthesia: a placebo-controlled study.

BACKGROUND: Since the effects of antiemetic doses of droperidol on the QT interval have not been previously studied, the authors designed a randomized, double-blind, placebo-controlled study to evaluate the intraoperative and postoperative effects of small-dose droperidol (0.625 and 1.25 mg intravenous) on the QT interval when used for antiemetic prophylaxis during general anesthesia. METHODS: One hundred twenty outpatients undergoing otolaryngologic procedures with a standardized general anesthetic technique were enrolled in this study. After anesthetic induction and before the surgical incision, 60 patients were given either saline or 0.625 or 1.25 mg intravenous droperidol in a total volume of 2 ml. A standard electrocardiographic lead II was recorded immediately before and every minute after the injection of the study medication during a 10-min observation period. The QTc (QT interval corrected for heart rate) was evaluated from the recorded electrocardiographic strips. In 60 additional patients, a 12-lead electrocardiogram was obtained before and at specific intervals up to 2 h after surgery to assess the effects of droperidol and general anesthesia on the QTc. Any abnormal heartbeats or arrhythmias during the operation or the subsequent 2-h monitoring interval were also noted. RESULTS: Intravenous droperidol, 0.625 and 1.25 mg, prolonged the QT interval by an average of 15 +/- 40 and 22 +/- 41 ms, respectively, at 3-6 min after administration during general anesthesia, but these changes did not differ significantly from that seen with saline (12 +/- 35 ms) (all values mean +/- SD). There were no statistically significant differences among the three study groups in the number of patients with greater than 10% prolongation in QTc (vs. baseline). Although general anesthesia was associated with a 14- to 16-ms prolongation of the QTc interval in the early postoperative period, there was no evidence of droperidol-induced QTc prolongation after surgery. Finally, there were no ectopic heartbeats observed on any of the electrocardiographic rhythm strips or 12-lead recordings during the perioperative period. CONCLUSION: Use of a small dose of droperidol (0.625-1.25 mg intravenous) for antiemetic prophylaxis during general anesthesia was not associated with a statistically significant increase in the QTc interval compared with saline. More importantly, there was no evidence of any droperidol-induced QTc prolongation immediately after surgery.

Optimal timing of acustimulation for antiemetic prophylaxis as an adjunct to ondansetron in patients undergoing plastic surgery.

We designed this study to evaluate the antiemetic efficacy of transcutaneous electrical acupoint stimulation in combination with ondansetron when applied before, after, or both before and after plastic surgery. A randomized, double-blind, sham-controlled study design was used to compare three prophylactic acustimulation treatment schedules: preoperative--an active device was applied for 30 min before and a sham device for 72 h after surgery; postoperative--a sham device was applied for 30 min before and an active device for 72 h after surgery; and perioperative--an active device was applied for 30 min before and 72 h after surgery (n = 35 per group). All patients received a standardized general anesthetic, and ondansetron 4 mg IV was administered at the end of surgery. The incidence of vomiting/retching and the need for rescue antiemetics were determined at specific time intervals for up to 72 h after surgery. Nausea scores were recorded with an 11-point verbal rating scale. Other outcome variables assessed included discharge times (for outpatients), resumption of normal activities of daily living, complete antiemetic response rate, and patient satisfaction with antiemetic therapy and quality of recovery. Perioperative use of the ReliefBand significantly increased complete responses (68%) compared with use of the device before surgery only (43%). Median postoperative nausea scores were significantly reduced in the peri- and postoperative (versus preoperative) treatment groups. Finally, patient satisfaction with the quality of recovery (83 +/- 16 and 85 +/- 13 vs 72 +/- 18) and antiemetic management (96 +/- 9 and 94 +/- 10 vs 86 +/- 13) on an arbitrary scale from 0 = worst to 100 = best was significantly higher in the groups receiving peri- or postoperative (versus preoperative) acustimulation therapy. For patients discharged on the day of surgery, the time to home readiness was significantly reduced (114 +/- 41 min versus 164 +/- 50 min; P < 0.05) when acustimulation was administered perioperatively (versus preoperatively). In conclusion, acustimulation with the ReliefBand was most effective in reducing postoperative nausea and vomiting and improving patients' satisfaction with their antiemetic therapy when it was administered after surgery.

Comparison of a lower-lipid propofol emulsion with the standard emulsion for sedation during monitored anesthesia care.

BACKGROUND: The currently used emulsion formulations of 1% propofol contain 10% soybean oil. However, a new emulsion of 1% propofol (Ampofol) containing 50% less lipid has recently become available for clinical investigation. This study was designed to compare the pharmacodynamic properties of Ampofol with those of a standard formulation (Diprivan) when administered for intraoperative sedation. METHODS: Sixty healthy outpatients undergoing minor operations with local anesthesia were randomly assigned to receive either Ampofol (n = 31) or Diprivan (n = 29) for intravenous sedation. The sedation was initiated with an intravenous loading dose of propofol, 0.75 mg/kg, followed by an initial infusion rate of 50 microg x kg(-1) x min(-1) to achieve an Observer's Assessment of Alertness/Sedation score of 3. The targeted level of sedation was maintained with a variable-rate propofol infusion during the operation. The onset times to achieving a sedation score of 3, the severity of pain on injection of the loading dose, intraoperative hemodynamic variables, and electroencephalographic Bispectral Index values were recorded. In addition, recovery times, postoperative pain and nausea, and patient satisfaction with the sedative medication were assessed. RESULTS: There were no significant differences between Ampofol and Diprivan with respect to onset times, dosage requirements, Bispectral Index values, hemodynamic variables, recovery times, or patient satisfaction scores. The incidence of moderate pain on injection was higher in the Ampofol group (26%vs. 7% with Diprivan; P < 0.05). CONCLUSIONS: Ampofol was equipotent to Diprivan with respect to its sedative properties during monitored anesthesia care. Although both groups received pretreatment with intravenous lidocaine, Ampofol was associated with more pain on injection.

The pharmacodynamic effects of a lower-lipid emulsion of propofol: a comparison with the standard propofol emulsion.

UNLABELLED: Using a randomized, double-blind protocol design, we compared a new lower-lipid emulsion of propofol (Ampofol) containing propofol 1%, soybean oil 5%, and egg lecithin 0.6% with the most commonly used formulation of propofol (Diprivan) with respect to onset of action and recovery profiles, as well as intraoperative efficacy, when administered for induction and maintenance of general anesthesia as part of a "balanced" anesthetic technique in 63 healthy outpatients. Anesthesia was induced with sufentanil 0.1 microg/kg (or fentanyl 1 microg/kg) and propofol 2 mg/kg IV and maintained with a variable-rate propofol infusion, 120-200 microg x kg(-1) x min(-1). Onset times to loss of the eyelash reflex and dropping a syringe were recorded. Severity of pain on injection, speed of induction, intraoperative hemodynamic variables, and electroencephalographic bispectral index values were assessed. Recovery times to opening eyes and orientation were noted. The results demonstrated that there were no significant differences between Ampofol and Diprivan with respect to onset times, speed of induction, anesthetic dose requirements, bispectral index values, hemodynamic variables, recovery variables, or patient satisfaction. However, the incidence of pain on injection was more frequent in the Ampofol group (26% versus 6%, P < 0.05). We conclude that Ampofol is equipotent to Diprivan with respect to its anesthetic properties but was associated with a more frequent incidence of mild pain on injection. IMPLICATIONS: The pharmacodynamic profile of a lower-lipid containing emulsion of propofol (Ampofol) was compared with Diprivan when administered for induction and maintenance of general anesthesia. This preliminary study demonstrated that the two formulations of propofol were equivalent with respect to their induction and maintenance properties. However, Ampofol was associated with a more frequent incidence of pain on injection.

Spinal anesthesia: functional balance is impaired after clinical recovery.

BACKGROUND: The ability of patients to walk without assistance after spinal anesthesia is a determining factor in the time to discharge following ambulatory surgery. The authors compared clinical markers of gross motor recovery with objective data of functional balance after spinal anesthesia. METHODS: Twenty-two male patients with American Society of Anesthesiology physical status I or II who were scheduled for perineal surgery were studied during recovery from spinal anesthesia to compare the predictive accuracy of clinical markers of ambulatory readiness (e.g., full knee flexion and extension) with that of an objective method of measurement focused on functional balance. Lumbar puncture was performed at the L2-L3 or L3-L4 interspace using a 25-gauge Whitacre needle, with patients in the sitting position. A 3-ml mixture of 5 mg bupivacaine (heavy) and 10 microg fentanyl was injected. Block regression and restoration of motor function were assessed and recorded. Functional balance was measured using a computerized force platform method. RESULTS: The majority of patients maintained motor function and proprioception sensation at the onset of surgical anesthesia, as indicated by performance on clinical tests of function: 96% were able to perform the straight leg increase; 82, 77, and 91%, respectively, were able to perform full knee flexion and extension, perform heel-to-shin maneuvers, and identify joint position in the supine position. Postoperatively, clinical return of motor function occurred much earlier than recovery of functional balance. At 60 min after onset of spinal anesthesia, 22 patients (100%) had recovered sensory and gross motor function, but only 36% could stand, and 8% could walk without assistance (P < 0.01). At 150-180 min after onset, 96-100% of patients achieved the levels of functional balance that permitted adequate ambulation. CONCLUSIONS: The results suggest that the recovery time to unassisted ambulation is longer than has been assumed, and that the standard clinical markers of gross motor function are poor predictors of functional balance following ambulatory surgery.

Titration of isoflurane using BIS index improves early recovery of elderly patients undergoing orthopedic surgeries.

PURPOSE: This study was designed to investigate the effect of bispectral index (BIS) monitoring on the recovery profiles, level of postoperative cognitive dysfunction, and anesthetic drug requirements of elderly patients undergoing elective orthopedic surgery with general anesthesia. METHODS: Sixty-eight patients over the age of 60 were randomized into one of two groups. In the standard practice (SP) group, the anesthesiologists were blinded to the BIS value, and isoflurane was titrated according to standard clinical practice. In the BIS group, isoflurane was titrated to maintain a BIS value between 50-60. RESULTS: The total isoflurane usage was 30% lower in the BIS group compared to the SP group (5.6 +/- 3 vs 7.7 +/- 3 mL, P <0.05). The time to orientation was faster in the BIS group compared to the SP group (9.5 +/- 3 vs 13.1 +/- 4 min, P <0.001). There were no differences in the postoperative psychometric tests between the two groups. CONCLUSIONS: There was no difference in the level of postoperative cognitive dysfunction between the two groups. However, titration of isoflurane using the BIS index decreased utilization of isoflurane and contributed to faster emergence of elderly patients undergoing elective knee or hip replacement surgery.

The assessment of postural stability after ambulatory anesthesia: a comparison of desflurane with propofol.

UNLABELLED: We designed this study to evaluate postural stability in outpatients after either desflurane or propofol anesthesia. After IRB approval, 120 consenting women undergoing gynecological laparoscopic procedures were randomly assigned to receive either desflurane or propofol-based general anesthesia. After surgery, patients' postural stability was measured as body sway velocity by using a computerized force platform in the following conditions: 1) standing on a firm surface with eyes open versus closed and 2) standing on a foam surface with eyes open versus closed. These measurements were made before anesthesia, immediately after the patient achieved a Post-Anesthesia Discharge Score of 9, and at actual discharge home. At the time patients first achieved a Post-Anesthesia Discharge Score of 9, the body sway in the Propofol group was significantly more than in the Desflurane group when patients were asked to stand on a foam surface with eyes closed (testing the ability of using vestibular information for balance control). We concluded that the desflurane-based anesthetic was associated with better postural control than the propofol-based anesthetic in the early recovery period after outpatient gynecological laparoscopic procedures. IMPLICATIONS: The residual effects of the short-acting general anesthetics desflurane and propofol on patient's balance function during recovery after surgery were assessed with a computerized force platform. The results showed that desflurane seemed to be associated with better postural control than propofol in the early recovery period.