Impact of a single perioperative dose of dexamethasone on the incidence of surgical site infections: a case-control study.

AIMS: Dexamethasone is recommended in several international guidelines to prevent postoperative nausea and vomiting, a problem especially frequent in gynecological patients. Despite the increasing use of dexamethasone for this indication there are limited data concerning potential harmful effects of corticosteroids in surgical patients, especially the potential negative impact on wound healing and surgical site infection (SSI). This case-control study was conducted to look for potentially harmful effects of a single perioperative dose of dexamethasone with respect to the occurrence of SSI in gynecological and obstetric surgery patients. MATERIALS AND METHODS: We retrospectively analyzed 3449 patients undergoing inpatient gynecological or obstetric surgical procedures for the occurrence of deep SSI requiring surgical intervention or prolonged antibiotic treatment. These case patients were matched to control patients according to the surgeon performing the procedure, the type of surgery, biometric data, and known risk factors for SSI. Furthermore, timely linearity of dexamethasone use and SSI rate was exploratorily analyzed using several auto-regressive, integrated, moving-average models. RESULTS: Forty patients with deep SSI were matched to 158 controls. The risk profile for wound infections of both groups was comparable. Forty-five percent (95% confidence interval: 29-62%) of the case patients were treated with dexamethasone and 49% (95% confidence interval: 41-57%) of the control group received the drug. An increasing use of dexamethasone over time was not followed by an increased SSI rate. There were no timely correlations between dexamethasone usage and the occurrence of SSI. CONCLUSION: In this case-control study we could not detect any evidence for an increased risk for SSI after a single-dose of dexamethasone (4-8 mg) in gynecological patients.

[Postoperative nausea and vomiting (PONV) - recommendations for risk assessment, prophylaxis and therapy - results of an expert panel meeting]. / Übelkeit und Erbrechen nach Operationen in Allgemeinanästhesie - Empfehlungen zur Risikoeinschätzung, Prophylaxe und Therapie.

BACKGROUND: The aim was to update recommendations concerning the management of postoperative nausea and vomiting (PONV) for German speaking countries. METHODS: An expert panel produced evidence-based, consented statements graded according to the Scottish Intercollegiate Guidelines Network (SIGN). RESULTS: Relevant risk factors for PONV include female gender, non-smoking status, history of PONV, history of motion sickness, use of intra- and postoperative opioids, volatile anesthetics and nitrous oxide. PONV scoring systems allow for an approximative risk assessment as a basis for a risk adapted approach. Since a risk-adapted prophylaxis vs. a risk-independent, fixed (combined) prophylaxis has not yet proven superior and because of inherent limitations of PONV scoring systems a fixed prophylaxis may be favourable. Regardless of the strategy for prophylaxis of PONV, high risk patients must be given a multimodal prophylaxis by avoiding known risk factors and applying multiple validated and effective antiemetic interventions. In the case of PONV immediate treatment is indicated due to its relevance for patients as well as the economic and medicolegal implications PONV may have. CONCLUSIONS: Given the impact of PONV on patient satisfaction and the availability of effective and safe measures to prevent and treat PONV, further efforts should be taken to actually implement present evidence in order to improve patient?s outcome following surgical procedures.

[High volume local infiltration analgesia (LIA) for total hip and knee arthroplasty: a brief review of the current status]. / Lokale Infiltrationsanästhesie (LIA) für Hüft- und Kniegelenksendoprothesen--Eine kurze Übersicht über den aktuellen Stand.

Local infiltration analgesia (LIA) is usually performed intraoperatively by the surgeon who injects 150 mL (300 mg Ropivacain, 30 mg Ketorolac and 0.5 mg adrenalin) into the bone, cartilage, ligament, musculature, or hyperdermis. A tight bandage and ice cooling for 4 - 6 hours lengthen the duration of analgesia, mobilisation can be undertaken about 5 hours after the operation. Besides large observation-in-use studies, there are 11 randomised studies in the fields of total hip and knee arthroplasty that report comparisons with systemic analgesia as well as with epidural or peripheral anaesthesia, all of which showed positive results for LIA. In addition LIA is safe, has favourable costs and does not require any special technical abilities in contrast to epidural and peripheral regional anaesthesia.

Randomised controlled trial of the effect of oral premedication with dexamethasone on hyperglycaemic response to abdominal hysterectomy.

BACKGROUND: This study was performed to evaluate the metabolic effects of a single oral dose of 8 mg dexamethasone in women undergoing hysterectomy. METHODS: Ninety non-diabetic women undergoing abdominal hysterectomy were randomised to receive 8 mg dexamethasone or placebo 2 h before surgery. Patients' perioperative care was standardised (fasting from midnight before surgery, balanced anaesthesia using propofol, fentanyl, remifentanil, cisatracurium, desflurane in oxygen/air). At five defined time points after drug administration (approximately 2, 4, 6, 10 and 14 h), blood samples were drawn under fasting conditions to measure blood glucose and free (non-esterified) fatty acids (NEFA). Data were analysed using analysis of variance for repeated measures. RESULTS: Data of 82 patients (dexamethasone: 44 and placebo: 38) were eligible for analysis. There was a statistically significant increase in blood glucose in both groups (P = 0.008). This increase was more pronounced in patients receiving dexamethasone (interaction term: P = 0.02) with maximum values at 6 h after surgery (or approximately 10 h after dexamethasone administration). There were 36 patients (placebo: 9 = 24% and dexamethasone: 27 = 61%) presenting with elevated glucose concentrations (>7 mmol l⁻¹) and 11 patients (placebo: 2 = 5% and dexamethasone: 9 = 20%) with hyperglycaemia (>8.5 mmol l⁻¹). There were no statistically significant changes in the plasma concentrations of NEFA during the perioperative period. CONCLUSION: Amounts of dexamethasone frequently used for prophylaxis of post-operative nausea and vomiting can cause short-lasting hyperglycaemia in the post-operative period, but no relevant alterations in fat metabolism. Thus, the benefits of administering corticosteroids should be weighed against the potential side-effects of short-lasting hyperglycaemia.

Efficacy of perphenazine to prevent postoperative nausea and vomiting: a quantitative systematic review.

BACKGROUND AND OBJECTIVE: despite the introduction of newer antiemetics in the prevention of postoperative nausea and vomiting (PONV), perphenazine is recommended in current guidelines, as the concept of multimodal management of PONV in high-risk patients requires more than two drugs to be combined. The aim of this quantitative systematic review was to assess the efficacy and safety of perphenazine in the prophylaxis of PONV in adults and children. METHODS: randomised controlled trials investigating the efficacy of perphenazine in the prevention of PONV in comparison with any other drug or placebo were systematically searched in MEDLINE, EMBASE, CINAHL and the Cochrane Library. Dichotomous data on the efficacy and adverse effects were combined and relative risks (RRs) as well as corresponding 95% confidence intervals (CIs) were calculated. RESULTS: eleven trials published between 1965 and 1999 including a total of 2081 participants fulfilled the inclusion criteria and were further analysed. In children, perphenazine 0.07 mg kg was effective in preventing vomiting (RR, 0.31; 95% CI, 0.18-0.54), whereas in adults, a dose of about 5 mg was effective for the prevention of PONV (RR, 0.50; 95% CI, 0.37-0.67). When compared with established newer drugs, for example, ondansetron, dexamethasone or droperidol, no significant differences were observed in the pooled analysis with limited data. Reporting of adverse events was poor. Transient sedation was reported in three eligible trials (RR, 0.9; 95% CI, 0.40-2.05). CONCLUSION: there is evidence that perphenazine is effective in the prevention of PONV in children and adults without serious adverse effects compared with placebo.

The effect of stimulating versus nonstimulating catheter techniques for continuous regional anesthesia: a semiquantitative systematic review.

BACKGROUND AND OBJECTIVES: Stimulating catheters provide feedback regarding the location of the catheter tip in relation to the target nerve or plexus. There is debate concerning whether stimulating catheters may reduce the failure rate of postoperative analgesia or whether they may enhance functional recovery by providing superior and more reliable postoperative analgesia. METHODS: Studies comparing the effect of stimulating versus nonstimulating catheters for postoperative analgesia were systematically and independently searched by 2 authors. RESULTS: Eleven randomized controlled studies could be included in this review. One trial was performed in volunteers; the others were clinical trials in patients. Five trials were performed in patients scheduled for a femoral nerve catheter, 4 for a distal sciatic nerve catheter, 1 in patients receiving an interscalene nerve catheter, and 1 in patients with an infraclavicular brachial plexus block. A standard quantitative analysis was deemed inappropriate because of considerable heterogeneity regarding the investigated outcome parameters. A semiquantitative review revealed that efficacy (judged by reduction in the need for rescue analgesics, complete surgery block, or median effective local anesthetic volume blocking the nerve) suggests improvement in stimulating catheters compared with nonstimulating catheters. Patient satisfaction as well as functional recovery was poorly investigated, so no conclusions could be drawn. CONCLUSIONS: Published reports of randomized controlled trials provide evidence for a better analgesic effect from stimulating catheters. Future trials should be conducted in a standardized manner with uniform reporting of outcomes, which may facilitate future quantitative analysis.

Systematic review on the recurrence of postoperative nausea and vomiting after a first episode in the recovery room - implications for the treatment of PONV and related clinical trials.

BACKGROUND: Despite the presence of a plethora of publications on the prevention of postoperative nausea and vomiting (PONV) only little is known how to treat established symptoms. Besides the high effort of performing these efficacy trials (much more patients must give their consent than are actually included in a study) and ethical concerns, little is known about the rate of re-occurring PONV/vomiting after placebo. As a consequence investigators will have difficulties defining a clinically relevant effect for the new treatment which is crucial for any planning. A quantitative systematic review was performed in order to provide more reliable estimates of the incidence of re-occurring PONV/vomiting after placebo and to help investigators defining a clinically relevant treatment effect. METHODS: A systematic search of the literature was performed using an extended search strategy of a previous review. Data on the recurrence of PONV (any nausea or emetic symptom) and vomiting (retching or vomiting) was extracted from published reports treating PONV with placebo and unpublished results from two observational trials where no treatment was given. A nonlinear random effects model was used to calculate estimates of the recurrence of symptoms and their 95%-confidence intervals (95%-CI). RESULTS: A total of 29 trials (including the unpublished data) were eligible for the calculations. Depending on the length of observation after administering placebo or no treatment the recurrence rate of PONV was between 65% (95%-CI: 53%...75%) and 84% (95%-CI: 73%...91%) and that of vomiting was between 65% (95%-CI: 44%...81%) and 78% (95%-CI: 59%...90%). CONCLUSION: Almost all trials showed a considerable and consistently high rate of recurrence of emetic symptoms after placebo highlighting the need for a consequent antiemetic treatment. Future (placebo) controlled efficacy trials may use the presented empirical estimates for defining clinically relevant effects and for statistical power considerations.

[Regional anaesthesia and analgesia for total knee replacement]. / Regionalanästhesie--Regionalanästhesie und Analgesie für die Kniegelenksendoprothetik.

Postoperative analgesia for total knee replacement with a continuous nerve catheter is more effective than any other form of systemic analgesia. For complete analgesia a combined technique of a femoral with a proximal sciatic nerve block is recommended. An easy and reliable way to achieve this is a femoral or a fascia iliaca compartment block together with a subgluteal sciatic nerve block.

Independent risk factors for postoperative shivering.

Postoperative shivering (PAS) is uncomfortable for patients and potentially risky. In this observational trial we sought to identify independent risk factors for PAS after general anesthesia. Potential risk factors for PAS were recorded in 1340 consecutive patients. Signs of shivering, peripheral and core temperature, and thermal comfort were recorded in the postanesthetic care unit. The data were split into an evaluation data set (n = 1000) and a validation data set (n = 340). The first was used to identify independent risk factors for PAS and to formulate a risk score using backward-elimination logistic regression analysis. The proposed model was subsequently tested for its discrimination and calibration properties using receiver operating characteristic (ROC)-curve analysis and linear correlation between the predicted and the actual incidences of PAS in the validation group. The incidence of PAS was 11.6%. There were three major risk factors: young age, endoprosthetic surgery, and core hypothermia, with age being the most important. The risk score derived from this analysis had a reasonable discriminating power, with an area under the ROC-curve of 0.69 (95% confidence interval, 0.60-0.78; P < 0.0001). Furthermore the equation of the calibration curve (y = 0.69x + 6; R2= 0.82; P < 0.05) indicated a good and statistically significant agreement between predicted and actual PAS incidence. Postoperative shivering can be predicted with acceptable accuracy using the four risk factors identified in the present study. The presented model may serve as a clinical tool to help clinicians to rationally administer prophylactic antishivering drugs.

Postoperative analgesia and functional recovery after total-knee replacement: comparison of a continuous posterior lumbar plexus (psoas compartment) block, a continuous femoral nerve block, and the combination of a continuous femoral and sciatic nerve block.

BACKGROUND AND OBJECTIVES: Continuous femoral nerve block is a well-accepted technique for regional analgesia after total-knee replacement. However, many patients still experience considerable pain at the popliteal space and at the medial aspect of the knee. The goal of this study is to evaluate whether a psoas compartment catheter provides better postoperative analgesia than a femoral nerve catheter does and whether it is as effective as the combination of a femoral and a sciatic nerve catheter and, thus, improves functional outcome. METHODS: Ninety patients who underwent total-knee replacement under standardized general anesthesia participated in this prospective randomized study. Group FEM received a continuous femoral nerve block, group FEM/SCI received a combination of a femoral and a sciatic continuous nerve block, and group PSOAS received a continuous psoas compartment block. Patient-controlled analgesia with piritramide was available for 48 hours. Maximal bending and extending of the knee and walking distance was assessed during the first 7 days. A standardized telephone survey was conducted after 9 to 12 months to evaluate residual pain and functional outcome. RESULTS: Postoperative opioid consumption during 48 hours was significantly less in the FEM/SCI group (median: 18 mg; 25th/75th percentile: 6/40) compared with the FEM group (49 mg; 25/66) and the PSOAS group (44 mg; 30/62) (P =.002). Postoperative pain scores were not different, and no differences occurred with respect to short-term or long-term functional outcome. CONCLUSION: The FEM/SCI catheter is superior to FEM and PSOAS catheter with respect to reduced analgesic requirements after total-knee replacement, but functional outcome does not differ with those 3 continuous regional analgesia techniques.

Does femoral nerve catheter placement with stimulating catheters improve effective placement? A randomized, controlled, and observer-blinded trial.

Continuous peripheral nerve blocks offer the benefit of extended postoperative analgesia and accelerated functional recovery after major knee surgery. Conventional nerve localization is performed over a stimulating needle followed by blind insertion of the peripheral catheter. Correct catheter placement is confirmed by testing for satisfactory analgesia. Stimulating catheters offer the advantage of verifying correct placement close to the nerve during catheter placement. The aim of this randomized trial was to determine whether accurate catheter positioning under continuous stimulation accelerates the onset of sensory and motor block, improves the quality of postoperative analgesia, and enhances functional recovery. We compared femoral nerve catheters inserted under continuous stimulation with catheters that were placed using the conventional technique of blind advancement in 81 patients undergoing major knee surgery. Time of catheter placement was similar in both groups with 4 min (3/7.3; median, 25th/75th percentile) in the conventional group and 5 min (4/8.8) in the stimulating catheter group. In both groups, 42% of the catheters could be correctly placed (motor response of the patella with a current < or =0.5 mA) at first attempt. In 22 patients (58%) of the stimulating catheter group, the catheter had to be redirected 1-20 times, including 2 that could not be correctly placed within 20 min. The onset time of sensory and motor block was almost similar in both groups. There were no differences in the postoperative IV opioid consumption, and visual analog scale pain scores at rest and movement, or maximal bending and stretching of the knee joint during the 5 days after surgery. We conclude that with continuous femoral nerve blocks, blind catheter advancement is as effective as the stimulating catheter technique with respect to onset time of sensory and motor block as well as for postoperative pain reduction and functional outcome.

Risk factors for bacterial catheter colonization in regional anaesthesia.

BACKGROUND: Although several potential risk factors have been discussed, risk factors associated with bacterial colonization or even infection of catheters used for regional anaesthesia are not very well investigated. METHODS: In this prospective observational trial, 198 catheters at several anatomical sites where placed using a standardized technique. The site of insertion was then monitored daily for signs of infection (secretion at the insertion site, redness, swelling, or local pain). The catheters were removed when clinically indicated (no or moderate postoperative pain) or when signs of potential infection occurred. After sterile removal they were prospectively analyzed for colonization, defined as > 15 colony forming units. RESULTS: 33 (16.7%) of all catheters were colonized, and 18 (9.1%) of these with additional signs of local inflammation. Two of these patients required antibiotic treatment due to superficial infections. Stepwise logistic regression analysis was used to identify factors associated with catheter colonization. Out of 26 potential factors, three came out as statistically significant. Catheter placement in the groin (odds-ratio and 95%-confidence interval: 3.4; 1.5-7.8), and repeated changing of the catheter dressing (odds-ratio: 2.1; 1.4-3.3 per removal) increased the risk for colonization, whereas systemic antibiotics administered postoperatively decreased it (odds ratio: 0.41; 0.12-1.0). CONCLUSION: Colonization of peripheral and epidural nerve catheter can only in part be predicted at the time of catheter insertion since two out of three relevant variables that significantly influence the risk can only be recorded postoperatively. Catheter localisation in the groin, removal of the dressing and omission of postoperative antibiotics were associated with, but were not necessarily causal for bacterial colonization. These factors might help to identify patients who are at increased risk for catheter colonization.

Factors influencing preoperative stress response in coronary artery bypass graft patients.

BACKGROUND: In many studies investigating measures to attenuate the hemodynamic and humoral stress response during induction of anaesthesia, primary attention was paid to the period of endotracheal intubation since it has been shown that even short-lasting sympathetic cardiovascular stimulation may have detrimental effects on patients with coronary artery disease. The aim of this analysis was, however, to identify the influencing factors on high catecholamine levels before induction of anaesthesia. METHODS: Various potential risk factors that could impact the humoral stress response before induction of anaesthesia were recorded in 84 males undergoing coronary aortic bypass surgery, and were entered into a stepwise linear regression analysis. The plasma level of norepinephrine measured immediately after radial artery canulation was chosen as a surrogate marker for the humoral stress response, and it was used as the dependent variable in the regression model. Accordingly, the mean arterial blood pressure, heart rate and the calculated pressure-rate product were taken as parameters of the hemodynamic situation. RESULTS: Stepwise regression analysis revealed that the oral administration of low-dose clonidine (mean dose 1.75 µg.kg-1) on the morning of surgery was the only significant predictor (p = 0.004) of the high variation in preoperative norepinephrine plasma levels. This intervention decreased norepinephrine levels by more than 40% compared to no clonidine administration, from 1.26 to 0.75 nmol.l-1. There was no evidence for dose-responsiveness of clonidine. All other potential predictors were removed from the model as insignificant (p > 0.05). The use of beta-blocker, ace-inhibitors, ejection fraction, and body mass index were significant determinants for the hemodynamic situation (heart rate, mean arterial pressure, pressure rate product) of the patient during the pre-induction period. CONCLUSION: The oral administration of clonidine is the only significant predictor for the observed variation of norepinephrine levels during the preoperative period. Lack of significant dose responsiveness suggests that even a low dose of the drug can attenuate the preoperative stress response and thus is recommended in cardiovascular high risk patients.

Patients' global evaluation of analgesia and safety of injected parecoxib for postoperative pain: a quantitative systematic review.

Parecoxib is the only parenterally administered cyclooxygenase-2-selective inhibitor available. We performed a systematic review, including full reports of randomized comparisons of parecoxib compared with any other analgesic intervention for prophylaxis or treatment of postoperative pain. Dichotomous data on patients' global evaluation of their analgesic regimen were extracted by means of the fraction of patients who rated their medication as "good" or "excellent." For safety analysis, data on any reported adverse effects were extracted. Relative risk (RR), number needed to treat (NNT), or number-needed-to-harm were calculated with 95% confidence intervals (CI). Data from 9 trials of 50 initially screened were finally analyzed. One thousand thirteen patients were randomized to receive parecoxib, 218 patients were allocated to an active control, and 507 patients received a placebo. With prophylactic administration, the pooled NNT to obtain the desired outcome ("good"/"excellent" rating) with parecoxib 20 and 40 mg compared with placebo was 4.5 (RR, 1.42; 95% CI, 0.91-2.24) and 4.0 (RR, 1.40; 95% CI, 1.10-1.79), respectively. In the treatment trials, the NNT to obtain the outcome of interest with parecoxib 20 mg was 2.1 (RR, 3.44; 95% CI, 1.49-7.96), 5.3 (RR, 1.43; 95% CI, 1.01-2.02), and -8.3 (RR, 0.85; 95% CI, 0.75-0.97) for the comparisons with placebo, morphine, and ketorolac, respectively. The corresponding NNT for treatment with parecoxib 40 mg was 1.7 (RR, 4.65; 95% CI, 2.04-10.61), 3.7 (RR, 1.62; 95% CI, 1.21-2.16), and 50 (RR, 1.03; 95% CI, 0.89-1.18) for the comparisons with placebo, morphine, and ketorolac, respectively. Overall adverse effects for parecoxib 20 and 40 mg were not different from those with placebo, morphine, or ketorolac. These results suggest a favorable profile for parecoxib compared with inactive or active controls. The optimal dose, timing, and frequency of administration need to be determined.

Droperidol and dolasetron alone or in combination for prevention of postoperative nausea and vomiting after vitrectomy.

PURPOSE: Droperidol and the new serotonin-3 antagonists are effective drugs for the prophylaxis of postoperative nausea and vomiting (PONV). The aim of this trial was to evaluate whether dolasetron could be a substitute for droperidol, because the Food and Drug Administration has required a Black Box warning on the droperidol package insert. DESIGN: Randomized, placebo-controlled, double-blinded trial. PARTICIPANTS: Inpatients undergoing vitreoretinal surgery (standard 3-port pars plana vitrectomy for proliferative diabetic vitreoretinopathy, complicated retinal detachment, or macular disease, such as macular pucker, macular hole, or choroidal neovascularization). INTERVENTION: Two hundred forty patients (3x80) receiving droperidol (10 microg. kg(-1)), dolasetron (12.5 mg), or the combination of both drugs administered 5 to 10 minutes before the end of surgery. CONTROL: Eighty patients received saline placebos as controls. METHODS: Standardized general anesthesia was performed, including benzodiazepine premedication, propofol, atracurium or vecuronium, desflurane in N(2)O/O(2), and a continuous infusion of remifentanil. Postoperative analgesia and antiemetic rescue medication were standardized. Episodes of vomiting, retching, nausea, and the need for additional antiemetics were recorded for 24 hours. MAIN OUTCOME MEASURES: Severity of PONV (rated by a standardized scoring algorithm) was analyzed as the main end point of the study using the Kruskal-Wallis test. RESULTS: Data of 304 patients could be analyzed. Mean severity scores in the placebo, dolasetron, droperidol, and combination groups were 1.21, 0.76, 0.47, and 0.30. Incidences of PONV of any severity were 56%, 40%, 28%, and 18%, respectively. The reduction of the incidence of PONV and its severity was statistically significant in the droperidol group and in the combination group relative to the placebo. Dolasetron alone failed to reduce the incidence of PONV. The combination of dolasetron and droperidol showed an additive antiemetic efficacy. CONCLUSION: Low-dose droperidol (10 microg. kg(-1)) but not dolasetron (12.5 mg) reduced postoperative nausea and vomiting after vitreoretinal surgery. Dolasetron (12.5 mg) is not an equivalent substitute for droperidol.

Ginger does not prevent postoperative nausea and vomiting after laparoscopic surgery.

IMPLICATIONS: The potential antiemetic effect of two different oral doses of the herbal remedy ginger (Zingiber officinale) to prevent postoperative nausea and vomiting in 180 patients undergoing gynecologic laparoscopy was investigated in this randomized, double-blinded trial. Ginger failed to reduce the incidence of postoperative nausea and vomiting after these procedures.

The efficacy and safety of transdermal scopolamine for the prevention of postoperative nausea and vomiting: a quantitative systematic review.

UNLABELLED: The role of scopolamine administered via transdermal therapeutic systems in the prevention of postoperative vomiting, nausea, and nausea and vomiting is unclear. We performed a systematic search for full reports of randomized comparisons of transdermal scopolamine with inactive control. Dichotomous data were extracted. In the meta-analysis, relative risks and numbers-needed-to-treat/harm were calculated with 95% confidence intervals (CI). In 23 trials, 979 patients received transdermal scopolamine, and 984 patients received placebo. Sensitivity analyses were performed using restricted data for truncated control event rates (40%-80%) and for large trials. With these data, the relative risks for postoperative vomiting (five reports), nausea (five reports), nausea and vomiting (eight reports), and rescue treatment (three reports) were 0.69 (95% CI, 0.58-0.82), 0.69 (95% CI, 0.54-0.87), 0.76 (95% CI, 0.66-0.88), and 0.68 (95% CI, 0.54-0.85), respectively. This means that of 100 patients who receive transdermal scopolamine, approximately 17 will not experience postoperative vomiting who would have done so had they all received a placebo. However, 18 of 100 patients will have visual disturbances, eight will report dry mouth, two will report dizziness, one will be classified as being agitated, and 1-13 patients who are prescribed transdermal scopolamine will not use it correctly. The timing of application does not alter efficacy. IMPLICATIONS: Of 100 patients who receive transdermal scopolamine, approximately 17 will not vomit in the postoperative period who would have done so had they all received a placebo. However, 18 of 100 patients will have visual disturbances, and eight will report dry mouth. Incorrect use further limits its efficacy.