A Prospective, Multicenter, Single-Blind Study Assessing Indices of SNAP II Versus BIS VISTA on Surgical Patients Undergoing General Anesthesia.

BACKGROUND: Traditionally, anesthesiologists have relied on nonspecific subjective and objective physical signs to assess patients' comfort level and depth of anesthesia. Commercial development of electrical monitors, which use low- and high-frequency electroencephalogram (EEG) signals, have been developed to enhance the assessment of patients' level of consciousness. Multiple studies have shown that monitoring patients' consciousness levels can help in reducing drug consumption, anesthesia-related adverse events, and recovery time. This clinical study will provide information by simultaneously comparing the performance of the SNAP II (a single-channel EEG device) and the bispectral index (BIS) VISTA (a dual-channel EEG device) by assessing their efficacy in monitoring different anesthetic states in patients undergoing general anesthesia. OBJECTIVE: The primary objective of this study is to establish the range of index values for the SNAP II corresponding to each anesthetic state (preinduction, loss of response, maintenance, first purposeful response, and extubation). The secondary objectives will assess the range of index values for BIS VISTA corresponding to each anesthetic state compared to published BIS VISTA range information, and estimate the area under the curve, sensitivity, and specificity for both devices. METHODS: This is a multicenter, prospective, double-arm, parallel assignment, single-blind study involving patients undergoing elective surgery that requires general anesthesia. The study will include 40 patients and will be conducted at the following sites: The Ohio State University Medical Center (Columbus, OH); Northwestern University Prentice Women's Hospital (Chicago, IL); and University of Miami Jackson Memorial Hospital (Miami, FL). The study will assess the predictive value of SNAP II versus BIS VISTA indices at various anesthetic states in patients undergoing general anesthesia (preinduction, loss of response, maintenance, first purposeful response, and extubation). The SNAP II and BIS VISTA electrode arrays will be placed on the patient's forehead on opposite sides. The hemisphere location for both devices' electrodes will be equally alternated among the patient population. The index values for both devices will be recorded and correlated with the scorings received by performing the Modified Observer's Assessment of Alertness and Sedation and the American Society of Anesthesiologists Continuum of Depth of Sedation, at different stages of anesthesia. RESULTS: Enrollment for this study has been completed and statistical data analyses are currently underway. CONCLUSIONS: The results of this trial will provide information that will simultaneously compare the performance of SNAP II and BIS VISTA devices, with regards to monitoring different anesthesia states among patients. CLINICALTRIAL: Clinicaltrials.gov NCT00829803; https://clinicaltrials.gov/ct2/show/NCT00829803 (Archived by WebCite at http://www.webcitation.org/6nmyi8YKO).

The relationship between the Bispectral Index (BIS) and the Observer Alertness of Sedation Scale (OASS) scores during propofol sedation with and without ketamine: a randomized, double blinded, placebo controlled clinical trial.

Prior studies have examined the static effect of intravenous ketamine on the BIS Index for sedation but it remains unknown if the BIS Index is a reliable method to track sedation levels in the presence of ketamine. The major objective of the current investigation was to compare the BIS Vista Index ability to track varying depths of sedation as determined by OASS scores in a standardized anesthetic regimen with and without ketamine. The study was a randomized, double blinded clinical trial. Patients undergoing breast surgery under sedation with propofol were randomized to receive ketamine (1.5 µg kg min(-1)) or saline. Infusion data was used to estimate propofol plasma concentrations (Cp). The main outcome of interest was the correlation between the BIS Vista Index with the OASS score. Twenty subjects were recruited and fifteen completed the study. Four hundred fifty-five paired data points were included in the analysis. Model performance (Nagelkerke R(2)) of the multinomial logistic regression model was 0.57 with the c-statistic of 0.87 (95 % CI 0.82-0.91). Compared to awake the odds ratio for BIS values predicting moderate sedation in the saline/propofol group 1.19 (95 % CI 1.12-1.25) but only 1.06 (95 % CI 1.02-1.1) in the ketamine/propofol group (P = 0.001). There was no difference in the odds for BIS values to predict deep sedation between groups (P = 0.14). The BIS monitor can be used to monitor sedation level even when ketamine is used with propofol as part of the sedation regimen. However, ketamine reduces the value of the BIS in predicting moderate sedation levels.

Desflurane/fentanyl compared with sevoflurane/fentanyl on awakening and quality of recovery in outpatient surgery using a laryngeal mask airway: a randomized, double-blinded controlled trial.

STUDY OBJECTIVE: To compare time to awakening and upper airway morbidity between desflurane and sevoflurane using a Laryngeal Mask Airway (LMA) and a balanced anesthetic regimen inclusive of opioids. DESIGN: Randomized, double-blinded, placebo-controlled clinical trial. SETTING: Ambulatory surgery unit of a university hospital. PATIENTS: 80 subjects receiving general anesthesia for outpatient gynecological surgery using a LMA. INTERVENTIONS: Desflurane/fentanyl or sevoflurane/fentanyl were used for anesthetic maintenance. MEASUREMENTS: Patients were randomly assigned to receive desflurane or sevoflurane. The primary outcome was time to awakening as determined by an observer who was blinded to study group allocation. Secondary outcomes included the frequency of sore throat, cough, and pain perioperatively and at 2 and 24 hours postoperatively. Quality of recovery (QoR; via QoR-40 questionnaire) at 24 hours also was determined. MAIN RESULTS: The median (IQR) time to eye opening following desflurane was 6.8 (5.0 - 9.8) minutes versus 11.8 (8.8 - 14.6) minutes following sevoflurane (P < 0.001), or a difference of 5.0 (99% CI 2.3 - 6.8) minutes. The median difference in response to verbal commands was 5.3 (99% CI 2.4 - 7.1) minutes. The frequency of cough, laryngospasm, sore throat, and hoarseness did not differ between groups. Quality of recovery at 24 hours was better in the desflurane group: difference in medians 6 (99% CI 0 - 12; P = 0.003). CONCLUSIONS: Desflurane retains faster awakening properties than does sevoflurane when used in combination with fentanyl as part of anesthetic maintenance in outpatient surgery with a LMA. The balanced anesthetic maintenance regimen seems to reduce the potential airway reactivity properties of desflurane.

Systemic lidocaine to improve postoperative quality of recovery after ambulatory laparoscopic surgery.

BACKGROUND: Perioperative systemic lidocaine has been shown to have beneficial postoperative analgesic effects. The only previous study examining the use of lidocaine in the outpatient setting did not detect an opioid-sparing effect after hospital discharge. More importantly, it is unknown whether systemic lidocaine provides a better postoperative quality of recovery to patients undergoing ambulatory surgery. Our objective in the current study was to examine the effect of systemic lidocaine on postoperative quality of recovery in patients undergoing outpatient laparoscopic surgery. METHODS: The study was a prospective, randomized, double-blind, placebo-controlled clinical trial. Healthy female subjects were randomized to receive lidocaine (1.5 mg/kg bolus followed by a 2 mg/kg/h infusion until the end of the surgical procedure) or the same volume of saline. The primary outcome was the Quality of Recovery-40 questionnaire at 24 hours after surgery. A 10-point difference represents a clinically relevant improvement in quality of recovery based on previously reported values on the mean and range of the Quality of Recovery-40 score in patients after anesthesia and surgery. Other data collected included opioid consumption, pain scores, and time to meet hospital discharge. Data were compared using group t tests and the Wilcoxon exact test. The association between opioid consumption and quality of recovery was evaluated using Spearman ρ. P < 0.01 was used to reject the null hypothesis for the primary outcome. RESULTS: Seventy subjects were recruited and 63 completed the study. There were no baseline differences regarding subject and surgical characteristics between the study groups. Patients in the lidocaine group had better global quality of recovery scores compared with the saline group, median difference of 16 (99% confidence interval [CI], 2-28), P = 0.002. Patients in the lidocaine group met hospital discharge criteria faster than the saline group, mean difference of -26 minutes (95% CI, -6 to -46 minutes) (P = 0.03). After hospital discharge, subjects in the lidocaine group required less oral opioids, median difference of -10 (95% CI, 0 to -30) (oral milligrams morphine equivalents), than the saline group (P = 0.01). There was an inverse association between postoperative opioid consumption and quality of recovery (ρ = 0.64, P < 0.001). CONCLUSIONS: Systemic lidocaine improves postoperative quality of recovery in patients undergoing outpatient laparoscopy. Patients who received lidocaine had less opioid consumption, which translated to a better quality of recovery. Lidocaine is a safe, inexpensive, effective strategy to improve quality of recovery after ambulatory surgery.

A dose-ranging study of the effect of transversus abdominis block on postoperative quality of recovery and analgesia after outpatient laparoscopy.

BACKGROUND: Postoperative pain can delay functional recovery after outpatient surgery. Multimodal analgesia can improve pain and possibly improve quality of recovery. In this study, we evaluated the dose-dependent effects of a preoperative transversus abdominis plane (TAP) block on patient recovery using the Quality of Recovery 40 (QoR-40) questionnaire after ambulatory gynecological laparoscopic surgery. Global QoR-40 scores range from 40 to 200, representing very poor to outstanding quality of recovery, respectively. METHODS: Healthy women undergoing outpatient gynecological laparoscopy were randomly allocated to receive a preoperative TAP block using saline, ropivacaine 0.25%, or ropivacaine 0.5%. Needle placement for the TAP blocks was performed using ultrasound guidance and 15 mL of the study solution was injected bilaterally by a blinded investigator. QoR-40 score and analgesic use were assessed 24 hours postoperatively. The primary outcome was global QoR-40 score at 24 hours after surgery. Data were analyzed using the Kruskal-Wallis test. Post hoc pairwise comparisons were made using the Dunn test with P values and 95% confidence intervals Bonferroni corrected for 6 comparisons. RESULTS: Seventy-five subjects were enrolled and 70 subjects completed the study. The median (range) for the QoR-40 score after the TAP block was 157 (127-193), 173 (133-195), and 172 (130-196) for the saline group and 0.25% and 0.5% ropivacaine groups, respectively. The median difference (99.2% confidence interval) in QoR-40 score for 0.5% bupivacaine (16 [1-30], P=0.03) and 0.25% bupivacaine (17 [2-31], P=0.01) was more than saline but not significantly different between ropivacaine groups (-1 [-16 to 12], P=1.0). Increased global QoR-40 scores correlated with decreased area under the pain score time curve during postanesthesia recovery room stay (ρ=-0.56, 99.2% upper confidence limit [UCL]=-0.28), 24-hour opioid consumption (ρ=-0.61, 99.2% UCL=-0.34), pain score (0-10 scale) at 24 hours (ρ=-0.53, 99.2% UCL=-0.25), and time to discharge readiness (ρ=-0.65, 99.2% UCL=-0.42). The aforementioned variables were lower in the TAP block groups receiving ropivacaine compared with saline. CONCLUSIONS: The TAP block is an effective adjunct in a multimodal analgesic strategy for ambulatory laparoscopic procedures. TAP blocks with ropivacaine 0.25% and 0.5% reduced pain, decreased opioid consumption, and provided earlier discharge readiness that was associated with better quality of recovery.

Postoperative epidural morphine for postpartum tubal ligation analgesia.

Women undergoing postoperative postpartum tubal ligation (PPTL) often experience considerable pain. We hypothesized that epidural morphine, as part of a multi-modal analgesic regimen, would decrease postoperative pain and the need for systemic analgesia after PPTL. In a double-blinded study, patients were randomized to receive epidural saline or morphine 2 mg, 3 mg, or 4 mg after epidural anesthesia for PPTL. Postoperatively, ibuprofen 600 mg was administered every 6 h and patients could request acetaminophen 325 mg/hydrocodone 10 mg. The primary outcome variable was time to first request for supplemental analgesia. Verbal rating scores for pain and the incidence and severity of side effects were recorded for 24 h. Morphine group subjects requested supplemental analgesia later and received fewer doses compared with the saline group subjects. Peak cramping and incisional verbal rating scores for pain and the area under the verbal rating scores for pain x time curve for cramping pain were less after epidural morphine compared with saline, but there were no differences among morphine groups. Nausea, vomiting, and pruritus occurred more often in all morphine groups and subjects who received morphine 4 mg required treatment for these side effects more frequently than the saline or morphine 2 mg groups. In conclusion, epidural morphine 2 mg as part of a multi-modal analgesic regimen improved analgesia and decreased the need for supplemental analgesics after PPTL. The need to treat side effects with morphine 2 mg was not increased compared to a regimen of oral acetaminophen/opioid/nonsteroidal antiinflammatory analgesics.

The risk of cesarean delivery with neuraxial analgesia given early versus late in labor.

BACKGROUND: Epidural analgesia initiated early in labor (when the cervix is less than 4.0 cm dilated) has been associated with an increased risk of cesarean delivery. It is unclear, however, whether this increase in risk is due to the analgesia or is attributable to other factors. METHODS: We conducted a randomized trial of 750 nulliparous women at term who were in spontaneous labor or had spontaneous rupture of the membranes and who had a cervical dilatation of less than 4.0 cm. Women were randomly assigned to receive intrathecal fentanyl or systemic hydromorphone at the first request for analgesia. Epidural analgesia was initiated in the intrathecal group at the second request for analgesia and in the systemic group at a cervical dilatation of 4.0 cm or greater or at the third request for analgesia. The primary outcome was the rate of cesarean delivery. RESULTS: The rate of cesarean delivery was not significantly different between the groups (17.8 percent after intrathecal analgesia vs. 20.7 percent after systemic analgesia; 95 percent confidence interval for the difference, -9.0 to 3.0 percentage points; P=0.31). The median time from the initiation of analgesia to complete dilatation was significantly shorter after intrathecal analgesia than after systemic analgesia (295 minutes vs. 385 minutes, P<0.001), as was the time to vaginal delivery (398 minutes vs. 479 minutes, P<0.001). Pain scores after the first intervention were significantly lower after intrathecal analgesia than after systemic analgesia (2 vs. 6 on a 0-to-10 scale, P<0.001). The incidence of one-minute Apgar scores below 7 was significantly higher after systemic analgesia (24.0 percent vs. 16.7 percent, P=0.01). CONCLUSIONS: Neuraxial analgesia in early labor did not increase the rate of cesarean delivery, and it provided better analgesia and resulted in a shorter duration of labor than systemic analgesia.

Impact of bispectral index monitoring on fast tracking of gynecologic patients undergoing laparoscopic surgery.

BACKGROUND: The need for increasing operating room efficiency has led to various initiatives, one of which is the elimination of mandatory admission to the phase I recovery area postoperatively, also referred to as fast tracking of ambulatory surgery patients. This Institutional Review Board-approved study was conducted to evaluate the effect of Bispectral Index (BIS) monitoring on the ability of patients to successfully bypass the phase I recovery area following gynecologic laparoscopy during general anesthesia. METHODS: Ninety-nine consenting patients were randomly assigned to one of two groups: group one, in which the BIS monitor (Aspect Medical Systems, Natick, MA) was used, and group two, in which no BIS monitor was used. All patients received a standardized anesthetic that included 1 microg/kg sufentanil and sevoflurane in oxygen, titrated in group one to a BIS value of 50-60 and in group two to maintain vital signs within 20% of preoperative values. All patients received prophylactic nonsteroidal antiinflammatory drugs and antiemetics. Postoperatively, patients were evaluated using the modified Aldrete scoring system, and those who achieved a score of 9 or higher within 10 min were permitted to bypass the phase I recovery area. RESULTS: There was no statistically significant difference between the two groups with respect to the number of patients who successfully bypassed the phase I recovery area, postoperative length of hospital stay, or cost of hospitalization. CONCLUSION: With a standardized anesthetic regimen and a strict discharge scoring system, BIS monitoring does not have a significant effect on the ability to fast track outpatients.