A. M. Morin

The development and validation of a risk score to predict the probability of postoperative vomiting in pediatric patients.

Risk scores to predict the occurrence of postoperative vomiting (PV) or nausea and vomiting that were developed for adult patients do not fit for children, because several risk factors are difficult to assess or are usually not applicable in pediatric patients (e.g., smoking status). Thus, in the present study, we sought to develop and to validate a simple score to predict PV in children (POVOC-score). Development and validation of the new score was based on data from 4 independent institutions of 1257 children (aged 0–14 yr) undergoing various types of surgery under general anesthesia without antiemetic prophylaxis. Preoperatively, several potential risk factors were recorded. Postoperatively, the occurrence of PV was observed for up to 24 h. The dataset was randomly split into an evaluation set (n = 657) that was analyzed using a forward logistic regression technique and a validation set (n = 600) that was used to confirm the accuracy of prediction by means of the area under a receiver operating characteristic curve. Four independent risk factors for PV were identified in the final analysis: duration of surgery ≥30 min, age ≥3 yr, strabismus surgery, and a positive history of PV in the children or PV/postoperative nausea and vomiting in relatives (mother, father, or siblings). The incidence of PV was 9%, 10%, 30%, 55%, and 70% for 0, 1, 2, 3, and 4 risk factors observed. Using these incidences as cut-off values in the validation dataset, the area under the receiver operating characteristic curve was 0.72 (95% confidence interval: 0.68–0.77). Our data suggest that PV can be predicted with an acceptable accuracy using a four-item simplified risk score.

Dimenhydrinate for prophylaxis of postoperative nausea and vomiting: a meta‐analysis of randomized controlled trials

Background: Diphenhydramine and its theoclate salt dimenhydrinate are traditional antiemetics still in use. However, so far the quantitative effect of dimenhydrinate in the prophylaxis of postoperative nausea and vomiting (PONV) has not been evaluated systematically.

The Efficacy and Safety of Transdermal Scopolamine for the Prevention of Postoperative Nausea and Vomiting: A Quantitative Systematic Review

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.

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 to12 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.

Impact of a multimodal anti-emetic prophylaxis on patient satisfaction in high-risk patients for postoperative nausea and vomiting

Postoperative nausea and vomiting (PONV) are frequent and unpleasant symptoms. This prospective study aimed to assess the efficacy of a multimodal approach to prevent PONV, and patient satisfaction using the willingness‐to‐pay method. Two validated risk scores were applied to forecast the individual risk for PONV in 900 consecutive patients of whom 108 were identified as high‐risk patients (predicted risk: 79–87%). High‐risk patients received multimodal anti‐emetic prophylaxis: total intravenous anaesthesia with propofol, high fractional inspired oxygen (80%), omission of nitrous oxide, dexamethasone 8 mg, haloperidol 10 µg.kg−1, and tropisetron 2 mg. Of the remaining patients with low or moderate risk for PONV, a random sample of 71 females received balanced propofol‐desflurane anaesthesia without prophylactic anti‐emetics. All patients were interviewed 2 and 24 h after surgery for occurrence of nausea and vomiting. Patient satisfaction was measured using the willingness‐to‐pay method. The incidence of PONV (95%‐confidence interval) in the control‐group was 41% (29–51%), slightly lower than predicted by the risk scores (53–57%). The multimodal anti‐emetic approach reduced the predicted risk (79–87%) in the high risk‐group to 7% (3–14%). This was associated with a high willingness‐to‐pay median (25th/75th percentile) of £84 (£33–184) in the multimodal anti‐emetic grouped compared to £14 (£4–30) in the control group. A multimodal anti‐emetic approach can considerably reduce the incidence of PONV in high‐risk patients and is associated with a high patient satisfaction as measured by the willingness‐to‐pay method.

Risk factors for bacterial catheter colonization in regional anaesthesia

BackgroundAlthough 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.MethodsIn 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.Results33 (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).ConclusionColonization 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.

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.

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 ≤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.

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.

Dexamethason zur Prophylaxe von Übelkeit und Erbrechen in der postoperativen Phase Eine Metaanalyse kontrollierter randomisierter Studien

ZusammenfassungFragestellung. Ziel der Untersuchung war die metaanalytische Aufarbeitung sämtlicher verfügbarer randomisierter, kontrollierter Studien, in denen Dexamethason allein oder in Kombination mit anderen Antiemetika zur Prophylaxe von Übelkeit und Erbrechen in der postoperativen Phase (PONV) eingesetzt wurde. Methodik. Es wurde eine systematische Literatursuche in den Literaturdatenbanken Medline, EMBASE und in der Cochrane-Library durchgeführt und Literaturverzeichnisse von Übersichtsarbeiten und aktuelle Ausgaben lokal verfügbarer Anästhesiejournale manuell durchsucht. Die Studien, die mit diesen Suchstrategien identifiziert worden waren, wurden in die vier folgenden Gruppen eingeteilt, die jeweils getrennt einer Metaanalyse unterzogen wurden: 1. Dexamethason vs. Plazebo, 2. Dexamethason+Partnerantiemetikum vs. Partnerantiemetikum allein, 3. Dexamethason+Partnerantiemetikum vs. Dexamethason allein, 4. Dexamethason vs. andere Antiemetika. Als Hauptzielgröße wurde jeweils der Anteil der Patienten extrahiert, der nach einer antiemetischen Prophylaxe während des postoperativen Beobachtungszeitraums komplett frei von Übelkeit und Erbrechen geblieben war. Daraus wurde die odds-ratio (OR), das relative Risiko (RR) und die “numbers-needed-to-treat” (NNT) jeweils mit den dazu gehörigen 95%-Konfidenzintervallen (jeweils in Klammern aufgeführt) mit einem Modell der zufälligen Effekte (random effects model) berechnet. Ergebnisse. Insgesamt wurden 26 Studien mit insgesamt 2561 Patienten in die Analysen aufgenommen.1. Als Einzelsubstanz ist Dexamethason zur Prophylaxe von PONV einer Plazebobehandlung deutlich überlegen (RR: 0,49 (0,15–0,42); NNT: 3,4 (2,5–5,3)).2. Wird Dexamethason zusammen mit einem anderen Antiemetikum (z. B. einem 5-HT3-Antagonisten) kombiniert, so erweist sich die Dexamethasonkombination der Einzelsubstanz als überlegen (RR: 0,60 (0,46–0,78); NNT: 7,3 (5,7–10,2)).3. Dasselbe gilt, wenn die Dexamethasonkombination mit Dexamethason allein verglichen wird. Auch hier schneidet die Kombination deutlich besser ab (RR: 0,16 (0,08–0,32); NNT: 3,2 (2,2–6,3)).4. Dexamethason wurde bisher v. a. mit 5-HT3-Antagonisten, seltener mit Dopaminantagonisten direkt verglichen. Bei diesen Vergleichen schneidet Dexamethason nicht schlechter ab als die Vergleichsantiemetika (RR: 1,35 (0,99–1,85); NNT: 10,6 (5,6–92,6)).Schlussfolgerungen. Dexamethason weist einen antiemetischen Effekt auf, der Plazebo überlegen und mit dem etablierter Antiemetika (5-HT3-Antagonisten / Dopaminantagonisten) vergleichbar ist. Besonders effektiv ist die Substanz, wenn sie in Kombination mit anderen Antiemetika gegeben wird. In diesem Fall verstärkt sie signifikant die antiemetische Wirkung der jeweiligen Partnersubstanz.AbstractObjective. Randomised controlled trials investigating the efficacy of dexamethasone alone or in combination with other antiemetics to prevent postoperative nausea and vomiting (PONV) were included in a meta-analysis to estimate the relative efficacy of these treatments. Methods. Studies were systematically searched using Medline, EMBASE, the Cochrane-Library, and by manual screening the reference lists and current issues of locally available anaesthesia journals. Studies identified were divided into four different groups. For each subgroup an independent analysis was performed: 1. Dexamethasone vs. placebo, 2. Dexamethasone+other antiemetic vs. other antiemetic alone, 3. Dexamethasone+other antiemetic vs. dexamethasone alone, 4. Dexamethasone vs. other antiemetics.The main end point in each study was defined as complete absence of nausea, retching, and vomiting after prophylactic antiemetic treatment. The pooled odds-ratios, the relative risk (RR) and the numbers-needed-to-treat (NNT) with their corresponding 95%-confidence intervals (given in parentheses) were calculated using a random effects model.Results. A total of 26 studies with 2561 patients were analysed.1. As a sole antiemetic agent dexamethasone is superior to placebo to prevent PONV (RR: 0,49 (0,15–0,42); NNT: 3,4 (2,5–5,3)).2. When dexamethasone and an other antiemetic (e.g. a 5-HT3-antagonist) are combined this drug combination is significantly more effective than the single antiemetic without dexamethasone (RR: 0,60 (0,46–0,78); NNT: 7,3 (5,7–10,2)).3. A similar result was obtained when the dexamethasone combination was compared with dexamethasone alone. The combination is statistically superior (RR: 0,16 (0,08–0,32); NNT: 3,2 (2,2–6,3)).4. Dexamethasone was usually compared with 5-HT3-antagonist and to a less extends also with dopamine antagonists. Summarising these studies, there was no significant difference concerning effectiveness (RR: 1,35 (0,99–1,85); NNT: 10,6 (5,6–92,6)).Conclusion. Dexamethasone has antiemetics effects that are superior to placebo treatment and are comparable with conventional antiemetic agents (e.g. 5-HT3-antagonist, dopamine antagonists). The drug is especially useful in combination with other antiemetics and increases the efficacy of the antiemetic partner drug.OBJECTIVE Randomised controlled trials investigating the efficacy of dexamethasone alone or in combination with other antiemetics to prevent postoperative nausea and vomiting (PONV) were included in a meta-analysis to estimate the relative efficacy of these treatments. METHODS Studies were systematically searched using Medline, EMBASE, the Cochrane-Library, and by manual screening the reference lists and current issues of locally available anaesthesia journals. Studies identified were divided into four different groups. For each subgroup an independent analysis was performed: 1. Dexamethasone vs. placebo, 2. Dexamethasone + other antiemetic vs. other antiemetic alone, 3. Dexamethasone + other antiemetic vs. dexamethasone alone, 4. Dexamethasone vs. other antiemetics. The main end point in each study was defined as complete absence of nausea, retching, and vomiting after prophylactic antiemetic treatment. The pooled odds-ratios, the relative risk (RR) and the numbers-needed-to-treat (NNT) with their corresponding 95%-confidence intervals (given in parentheses) were calculated using a random effects model. RESULTS A total of 26 studies with 2561 patients were analysed. 1. As a sole antiemetic agent dexamethasone is superior to placebo to prevent PONV (RR: 0.49 (0.15-0.42); NNT: 3.4 (2.5-5.3)). 2. When dexamethasone and an other antiemetic (e.g. a 5-HT3-antagonist) are combined this drug combination is significantly more effective than the single antiemetic without dexamethasone (RR: 0.60 (0.46-0.78); NNT: 7.3 (5.7-10.2)). 3. A similar result was obtained when the dexamethasone combination was compared with dexamethasone alone. The combination is statistically superior (RR: 0.16 (0.08-0.32); NNT: 3.2 (2.2-6.3)). 4. Dexamethasone was usually compared with 5-HT3-antagonist and to a less extends also with dopamine antagonists. Summarising these studies, there was no significant difference concerning effectiveness (RR: 1.35 (0.99-1.85); NNT: 10.6 (5.6-92.6)). CONCLUSION Dexamethasone has antiemetics effects that are superior to placebo treatment and are comparable with conventional antiemetic agents (e.g. 5-HT3-antagonist, dopamine antagonists). The drug is especially useful in combination with other antiemetics and increases the efficacy of the antiemetic partner drug.