Lynne Harris

Multimodal antiemetic management prevents early postoperative vomiting after outpatient laparoscopy.

Because no completely effective antiemetic exists for the prevention of postoperative nausea and vomiting (PONV), we hypothesize that a multimodal approach to management of PONV may reduce both vomiting and the need for rescue antiemetics in high-risk patients. After IRB approval, women undergoing outpatient laparoscopy were randomized to one of three groups. Group I (n = 60) was managed by using a predefined multimodal clinical care algorithm. Patients undergoing the same surgical procedure who received a standard balanced outpatient anesthetic with ondansetron 4 mg (Group II, n = 42) or placebo (Group III, n = 37) prophylaxis were chosen to establish baseline incidence of nausea and vomiting. None of the Group I patients vomited before discharge, compared with 7% in Group II (P = 0.07) and 22% in Group III (P = 0.0003). However, one patient (2%) in Group I required treatment for symptoms in the postanesthesia care unit, compared with 24% in Group II (P < 0.0001) and 41% in Group III (P < 0.0001). Time to discharge-ready was significantly shorter in Group I (128, 118–139 min; mean, 95% confidence interval) versus Group II (162, 145–181 min;P = 0.0015) and Group III (192, 166–222 min;P = 0.0001). Patient satisfaction with control of PONV was not different between Group I and Group II. Return to normal daily activity and overall satisfaction were not different among groups. Multimodal management resulted in a 98% complete response rate and a 0% incidence of vomiting before discharge; however, this improvement did not result in an increased level of patient satisfaction when compared with routine monotherapy prophylaxis. We conclude that both multimodal management and routine monotherapy antiemetic prophylaxis resulted in an increased level of patient satisfaction than symptomatic treatment in this high-risk population. Implications Use of a multimodal clinical care algorithm eliminates predischarge vomiting and improves satisfaction in patients undergoing outpatient laparoscopy.

Multifactorial Preoperative Predictors for Postcesarean Section Pain and Analgesic Requirement

Background: The study aimed to determine predictive factors for postcesarean pain and analgesia using an assessment of pain threshold and suprathreshold thermal stimuli as well as degree of somatization and anxiety. Methods: Thirty-four healthy parturients scheduled for cesarean delivery under subarachnoid anesthesia were enrolled. Preoperative thermal pain threshold, intensity, and unpleasantness to heat stimuli applied to arm and lower back, State Trait Anxiety Inventory, and patient expectation for postoperative pain and need for analgesia were assessed. After surgery, overall, resting, and movement pain and analgesic consumption were recorded. Prediction of pain and analgesic use outcomes was made by principal component factor analysis, followed by stepwise linear regression. Results: Resting pain was predicted by two factors, thermal pain and unpleasantness and patient expectation (r2 = 0.26, P < 0.01), evoked pain by thermal pain threshold in the back (r2 = 0.20, P < 0.009), composite pain by thermal pain and unpleasantness and preoperative blood pressure (r2 = 0.28, P < 0.008), intraoperative analgesic need by preexisting pain (r2 = 0.22, P < 0.006), recovery room analgesia by thermal pain threshold and State Trait Anxiety Inventory (r2 = 0.27, P < 0.01), and total analgesic need by State Trait Anxiety Inventory (r2 = 0.22, P < 0.01). These models predicted the upper twentieth percentile of composite pain scores and analgesic requirement with sensitivity of 0.71 to 0.80 and specificity of 0.76 to 0.80. Conclusions: The authors’ results suggest a meaningful combination of preoperative patient responses from physical and psychological tests yields a valid multifactorial predictive model for postoperative pain and analgesic requirement with significant improvements over individual predictive variables.

Antiemetic prophylaxis does not improve outcomes after outpatient surgery when compared to symptomatic treatment

BACKGROUND Although prophylactic administration of antiemetics reduces the incidence of postoperative nausea, vomiting, or both (PONV), there is little evidence to suggest this improves patient outcomes. The authors hypothesized that early symptomatic treatment of PONV will result in outcomes, including time to discharge, unanticipated admission, patient satisfaction, and time to return to normal daily activities, that are similar to those achieved with routine prophylaxis. METHODS Men and women (n = 575) scheduled for outpatient surgery during general anesthesia were randomized to receive either 4 mg intravenous ondansetron or placebo before operation and either 1 mg intravenous ondansetron or placebo if postoperative symptomatic treatment of PONV was necessary. Patients were stratified into subgroups by risk factors for PONV. RESULTS No differences occurred in the time to discharge, rate of unanticipated admission, or time to return to normal activity between the prophylaxis and treatment groups. The reported level of satisfaction with control of PONV was 93% in the treatment arm and 97% in the prophylaxis arm, which fall within the limits defined a priori as clinically equivalent. Female patients with a history of motion sickness or PONV who were undergoing highly emetogenic procedures had a higher reported level of satisfaction with prophylaxis than with treatment (100% vs. 90%, P = 0.043); however, the level of satisfaction with the overall outpatient surgical experience was not different. CONCLUSION Although PONV is unpleasant, the data indicate little difference in outcomes when routine prophylactic medications are administered versus simply treating PONV should symptoms occur.

Antiemetic Prophylaxis for Postdischarge Nausea and Vomiting and Impact on Functional Quality of Living During Recovery in Patients with High Emetic Risks: A Prospective, Randomized, Double-Blind Comparison of Two Prophylactic Antiemetic Regimens

BACKGROUND: We compared two antiemetic prophylaxis regimens, their efficacy for preventing postdischarge nausea and vomiting, and their impact on quality of living, during recovery. METHODS: Sixty-four women undergoing outpatient gynecological surgery and at high risk for emesis were randomized into one of two groups. The study group received intraoperative IV dexamethasone 8 mg and ondansetron 4 mg, followed with an 8 mg oral disintegrating ondansetron tablet, to be taken on discharge and in the morning of postoperative days 1 and 2. The control group received only the IV ondansetron 4 mg intraoperatively. The incidence and severity of emetic symptoms and pain were assessed while patients were in the recovery room and via telephone and patient diary for 5 days after discharge. A modified functional living index of emesis was used to assess the impact on quality of living during recovery. RESULTS: Sixty patients, 30 in each group, completed the study. The incidences for postdischarge nausea were 57% and 20%, and for postdischarge vomiting 20% and 3% in the control and study groups, respectively, for the period between the 8th and 120th hours postanesthesia (P < 0.05). Thirty-three percent of the study and 60% of the control group reported that emetic symptoms negatively affected their quality of living (P < 0.05). CONCLUSIONS: When compared with a single dose of intraoperative IV ondansetron prophylaxis, our study regimen of additional intraoperative dexamethasone and once a day ondansetron significantly reduced the incidence of postdischarge nausea and vomiting and its negative impact on quality of living during the first 5 days of recovery.

Dural puncture with a 27-gauge Whitacre needle as part of a combined spinal-epidural technique does not improve labor epidural catheter function.

Background:This prospective, double-blind, randomized study was designed to examine whether the combined spinal–epidural technique without subarachnoid drug administration improved epidural catheter function when compared with the traditional epidural technique. Methods:After institutional review board approval and informed consent, 251 healthy laboring parturients were randomly assigned to either group DP (combined spinal–epidural technique with 27-gauge Whitacre needle dural puncture but without subarachnoid drug administration) or group NoDP (traditional epidural technique). Patient-controlled epidural analgesia was initiated with 0.11% bupivacaine and 2 &mgr;g/ml fentanyl. Top-up doses in 5-ml increments of 0.25% bupivacaine were administered if needed. Previous power analysis revealed that a sample size of 108 patients/group was needed to show a clinically useful reduction of the catheter manipulation rate from 32% to 15%. Results:In groups DP and NoDP, 107 and 123 evaluable patients, respectively, completed the study. Demographics and outcome variables measured, including epidural catheter manipulation and replacement rate, sacral sparing, unilateral block, number of top-up doses, average hourly epidural drug usage, highest sensory blockade level, and labor analgesia quality, were not different between groups. A subgroup of 18 patients without cerebral spinal fluid return during dural puncture had a higher catheter replacement rate than those of groups DP and NoDP, but it did not reach statistical significance. Conclusions:Dural puncture with a 27-gauge Whitacre needle without subarachnoid drug administration during combined spinal–epidural labor analgesia did not improve epidural labor analgesia quality or reduce catheter manipulation or replacement rate when compared with a traditional epidural technique.

Small-dose propofol by continuous infusion does not prevent postoperative vomiting in females undergoing outpatient laparoscopy

This study was designed to test the hypothesis that there is a direct prophylactic antiemetic effect of small-dose propofol given by continuous infusion. Sixty female patients undergoing outpatient laparoscopy under general anesthesia were randomized to receive, in a double-blind fashion, either a bolus of 0.1 mg/kg followed by a constant infusion of 1 mg [center dot] kg-1 [center dot] h-1 of propofol or an equivalent volume of 10% Intralipid[R] (placebo) beginning 30 min before induction of anesthesia and continuing until discharge from Stage I postanesthesia care unit (PACU). Anesthesia was induced and maintained in a standard fashion in all patients. The number of emetic episodes before and after discharge from PACU, nausea scores (11-point numerical scale), and time to discharge were evaluated. No significant differences between Intralipid[R] and propofol were found for any of the outcome variables tested. While small-dose propofol is an effective adjuvant in reducing chemotherapy-induced emesis, we were unable to demonstrate any beneficial effect of propofol in reducing postoperative nausea and vomiting when used as the sole prophylactic medication in this patient population. Propofol may have a synergistic effect when administered with other antiemetics, or the specific antiemetic effect of propofol, if it exists, may be dose-dependent and the dose used in this study was below the efficacy threshold. (Anesth Analg 1997;84:71-5)

Chronobiology of Subarachnoid Fentanyl for Labor Analgesia

Background:Chronobiology studies the recurrent biologic rhythms that directly affect how an organism interacts with its environment and how its environment affects the organism. The purpose of this study is to determine whether the time of administration influences the analgesic duration of the commonly used subarachnoid fentanyl for labor analgesia. Methods:After institutional review board approval and informed consent were obtained, 77 healthy nulliparous women in active labor requesting neuraxial analgesia were assigned to one of two groups, based on the time of combined spinal–epidural analgesia placement: the day group, for the time period from 12:00 to 18:00, and the night group, for the period from 20:00 to 02:00. Combined spinal–epidural analgesia was performed with 20 &mgr;g subarachnoid fentanyl. An epidural catheter was inserted but not dosed until patients requested further analgesia. Dynamic data were recorded at 5-min intervals for 20 min initially and then every 15 min. The analgesic duration was defined as the time from subarachnoid fentanyl injection to the time the patient requested further analgesia. Results:Seventy evaluable patients completed the study, with 35 per group. Patient demographics, visual analog pain scale scores, and labor characteristics were similar between groups, but the duration (mean ± SD) for subarachnoid fentanyl labor analgesia was 92 ± 34 min for the day group and 67 ± 21 min for the night group (P < 0.001). Conclusions:The results indicate that chronobiology of subarachnoid fentanyl plays a significant role of up to 27% difference in labor analgesic duration between the two administration time periods studied. Chronobiology should be incorporated in future comparative studies or analysis of previous studies on subarachnoid fentanyl.

Predicting Acute Pain after Cesarean Delivery Using Three Simple Questions

Background:Interindividual variability in postoperative pain presents a clinical challenge. Preoperative quantitative sensory testing is useful but time consuming in predicting postoperative pain intensity. The current study was conducted to develop and validate a predictive model of acute postcesarean pain using a simple three-item preoperative questionnaire. Methods:A total of 200 women scheduled for elective cesarean delivery under subarachnoid anesthesia were enrolled (192 subjects analyzed). Patients were asked to rate the intensity of loudness of audio tones, their level of anxiety and anticipated pain, and analgesic need from surgery. Postoperatively, patients reported the intensity of evoked pain. Regression analysis was performed to generate a predictive model for pain from these measures. A validation cohort of 151 women was enrolled to test the reliability of the model (131 subjects analyzed). Results:Responses from each of the three preoperative questions correlated moderately with 24-h evoked pain intensity (r = 0.24–0.33, P < 0.001). Audio tone rating added uniquely, but minimally, to the model and was not included in the predictive model. The multiple regression analysis yielded a statistically significant model (R2 = 0.20, P < 0.001), whereas the validation cohort showed reliably a very similar regression line (R2 = 0.18). In predicting the upper 20th percentile of evoked pain scores, the optimal cut point was 46.9 (z =0.24) such that sensitivity of 0.68 and specificity of 0.67 were as balanced as possible. Conclusions:This simple three-item questionnaire is useful to help predict postcesarean evoked pain intensity, and could be applied to further research and clinical application to tailor analgesic therapy to those who need it most.

Anesthetic and obstetric outcomes in morbidly obese parturients: a 20-year follow-up retrospective cohort study

BACKGROUND In 1993, Hood and Dewan published the results of a trial comparing obstetric and anesthetic outcomes of 117 morbidly obese parturients with matched controls. The authors demonstrated a higher initial epidural anesthesia failure rate, a higher cesarean delivery rate and an increased risk of obstetric complications. We replicated the previous study to provide updated information on outcomes in the morbidly obese pregnant population. We hypothesized that morbidly obese women would still have higher complication and failure rates compared to matched controls and that general anesthesia would be less commonly used than in the previous study. METHODS The medical records of 230 patients weighing >136 kg (300 pounds) were compared to matched controls: the next patient delivered by the same obstetrician with a weight <113 kg (250 pounds). RESULTS The mean body mass index of the morbidly obese group was 53.4 ± 6.6 kg/m² [corrected] compared to 31.1±5.4 kg/m2 in the control group. Fifty percent of morbidly obese women required cesarean delivery compared to 32% of controls (P < 0.01). Morbidly obese patients had a longer first stage of labor (P < 0.01), larger neonates (P < 0.01), and were more likely to have a failed initial neuraxial technique for labor analgesia (P < 0.01). The need for a replacement procedure for labor was 17%, significantly less than 20 years ago when 42% of catheters in morbidly obese women failed (P < 0.01). Failure rates of neuraxial anesthesia for cesarean delivery were similar between groups. Neuraxial procedure times were greater in morbidly obese parturients (P < 0.01). Morbidly obese women were less likely to receive general anesthesia compared to 20 years ago (3% vs. 24%, P < 0.01). CONCLUSIONS Morbidly obese parturients are still at increased risk for antenatal comorbidities, failed labor analgesia, longer first stage of labor and operative delivery. Replacement labor epidural catheters and general anesthesia for cesarean delivery are less commonly required anesthetic techniques compared to the original study.

Neostigmine Decreases Bupivacaine Use by Patient-Controlled Epidural Analgesia During Labor: A Randomized Controlled Study

BACKGROUND: Intrathecal neostigmine not only produces analgesia but also severe nausea. In contrast, epidural neostigmine enhances opioid and local anesthetic analgesia without causing nausea. Previous studies examined only single epidural neostigmine bolus administration and did not assess the efficacy of continuous epidural infusion or several aspects of maternal and fetal safety. We therefore tested the hypothesis that epidural neostigmine in combination with bupivacaine by continuous infusion during labor would reduce the amount of bupivacaine required. METHODS: Twelve healthy women scheduled for elective cesarean delivery were assigned to receive epidural neostigmine, 40 μg (first six subjects) or 80 μg (second six subjects) as a single bolus, with fetal heart rate (FHR) and uterine contractions monitored for 20 min. In a subsequent experiment, 40 healthy laboring women were randomized to receive bupivacaine 1.25 mg/mL alone or with neostigmine 4 μg/mL by patient-controlled epidural analgesia. The primary outcome measure was hourly bupivacaine use. RESULTS: Epidural neostigmine bolus did not alter baseline FHR, induce contractions, or produce nausea. Epidural neostigmine infusion reduced bupivacaine requirement by 19% in all patients and 25% in those with >4 h of treatment (P < 0.05 for both) but might have contributed to the incidence of mild sedation. Mode of delivery, incidence of maternal nausea, and FHR abnormality were similar between groups. CONCLUSIONS: These data show that adding epidural neostigmine 4 μg/mL reduces the hourly bupivacaine requirement by 19%–25% with patient-controlled epidural analgesia during labor. Administered as a bolus and by continuous infusion at the studied doses, epidural neostigmine does not cause nausea and does not induce uterine contractions or FHR abnormalities, but mild sedation can occur.