[Prevention and treatment of postoperative nausea and vomiting in children. An evidence-based approach]

Impact of the mode of hospitalisation on the postoperative complication rate after dissection tonsillectomy in children

OBJECTIVES

To compare postoperative complication rates after dissection tonsillectomy in patients operated by outpatient surgery and patients operated by inpatient surgery.

POPULATION AND METHODS

A prospective, single-centre, observational study was conducted over a period of 1 year. Dissection tonsillectomy was performed in 103 patients (mean age: 4 years) between September 2011 and September 2012. The following parameters were studied: bleeding or inflammatory complication rate, readmissions, unscheduled visits, factors contraindicating outpatient surgery, reasons for failure of outpatient surgery and influence of Postoperative Nausea and Vomiting scores.

RESULTS

Two patient groups were composed: 54 patients were managed by outpatient surgery (Group O) and 49 patients were managed by inpatient surgery (Group I). The two main factors contraindicating outpatient surgery were age less than 3 years (40%) and preoperative suspicion of sleep apnoea-hypopnoea syndrome (26%). Seven patients of Group O had to stay in hospital (outpatient failure rate of 13%). Postoperative complications were observed in 13% of patients of Group O versus 12.2% of patients of Group I with no statistically significant difference between the two groups. One patient in each group had to be readmitted; no statistically significant difference was observed between the two groups (P=0.41). PONV scores were very high (2) in all cases.

CONCLUSION

Outpatient tonsillectomy in well-selected patients is not associated with a higher postoperative complication rate than inpatient tonsillectomy. With systematic appropriate prophylaxis, Postoperative Nausea and Vomiting scores had no influence on the postoperative course.

Postoperative vomiting in pediatric oncologic patients: prediction by a fuzzy logic model

OBJECTIVE

To report a fuzzy logic mathematical model to predict postoperative vomiting (POV) in pediatric oncologic patients and compare with preexisting scores.

BACKGROUND

Although POV has a high incidence in children and may decrease parental satisfaction after surgeries, there is only one specific score that predicts POV in children: the Eberhart's score. In this study, we report a fuzzy model that intends to predict the probability of POV in pediatric oncologic patients. Fuzzy logic is a mathematical theory that recognizes more than simple true and false values and takes into account levels of continuous variables such as age or duration of the surgery. The fuzzy model tries to account for subjectiveness in the variables.

METHODS

Preoperative potential risk factors for POV in 198 children (0-19 year old) with malignancies were collected and analyzed. Data analysis was performed with the chi-square test and logistic regression to evaluate probable risk factors for POV. A system based on fuzzy logic was developed with the risk factors found in the logistic regression, and a computational interface was created to calculate the probability of POV.

RESULTS

The model showed a good performance in predicting POV. After the analysis, the model was compared with Eberhart's score in the same population and showed a better performance.

CONCLUSIONS

The fuzzy score can predict the chance of POV in children with cancer with good accuracy, allowing better planning for postoperative prophylaxis of vomiting. The computational interface is available for free download at the internet and is very easy to use.

[Low-dose droperidol in children: rescue therapy for persistent postoperative nausea and vomiting]

BACKGROUND

Droperidol had been used as an effective antiemetic since the 1970s but was withdrawn from the market in 2001 because of a black box warning about QT prolongation and possible cardiac arrhythmia after high doses. In the meantime the black box warning has seriously been questioned and parenteral droperidol has again been licensed in 2008. Because droperidol acts on dopaminergic receptors different to 5-HT(3) antagonists and dexamethasone, it could possibly serve as a rescue drug after failed postoperative nausea and vomiting (PONV) prophylaxis. Persistent PONV after the recommended prophylaxis is a significant problem in pediatric anesthesia but a satisfactory strategy has not yet been defined. Therefore a retrospective audit was performed in order to evaluate whether low-dose droperidol (10 µg/kgBW) would be an effective rescue drug for failed antiemetic prophylaxis.

PATIENTS AND METHODS

The electronic anesthesia patient data base of the University Children's Hospital Zurich was searched from 2004-2009 for patients who received low-dose droperidol in the postanesthesia care unit as rescue therapy for persistent PONV after antiemetic prophylaxis. Based on the recorded electronic data the effectiveness of low-dose droperidol as PONV rescue therapy and possible side effects were analyzed.

RESULTS

A total of 338 patients who received droperidol were found from a total of 34,032 patients and the charts were analyzed. Of these patients 134 were excluded because they had received droperidol for indications other than PONV, 43 patients were excluded because they had not received antiemetic prophylaxis before droperidol and in 17 patients the data were incomplete, leaving 144 patients with an average age of 12.3 years (interquartile range IQR 9.5-15.2 years) for analysis. The upper range of ages resulted from patients with chronic diseases who were still being treated in the Children's Hospital. Low-dose droperidol was given because of persistent nausea to 59 patients (41%) and to 85 patients (59%) for persistent vomiting. Initial antiemetic prophylaxis and/or therapy had consisted of dexamethasone plus tropisetrone in 80 patients and tropisetrone or dexamethasone alone in 64 patients. In 128 patients (89%) rescue therapy with a median dose of 10.9 µg/kgBW droperidol was effective but vomiting persisted in 16 patients (11%). Sedation was the only side effect recorded and this was observed in 39 patients (27%).

CONCLUSIONS

Low-dose droperidol (10 µg/kgBW) was found to be effective as rescue medication in pediatric patients experiencing PONV despite various prophylactic antiemetic regimens. No neurological or cardiopulmonary side effects were recorded after this low dosage.

Children's vomiting following posterior fossa surgery: A retrospective study

BACKGROUND

Nausea and vomiting is a problem for children after neurosurgery and those requiring posterior fossa procedures appear to have a high incidence. This clinical observation has not been quantified nor have risk factors unique to this group of children been elucidated.

METHODS

A six year retrospective chart audit at two Canadian children's hospitals was conducted. The incidence of nausea and vomiting was extracted. Hierarchical multivariable logistic regression was used to quantify risk and protective factors at 120 hours after surgery and early vs. late vomiting.

RESULTS

The incidence of vomiting over a ten day postoperative period was 76.7%. Documented vomiting ranged from single events to greater than 20 over the same period. In the final multivariable model: adolescents (age 12 to <17) were less likely to vomit by 120 hours after surgery than other age groups; those who received desflurane, when compared to all other volatile anesthetics, were more likely to vomit, yet the use of ondansetron with desflurane decre kelihood. Children who had intraoperative ondansetron were more likely to vomit in the final multivariable model (perhaps because of its use, in the clinical judgment of the anesthesiologist, for children considered at risk). Children who started vomiting in the first 24 hours were more likely to be school age (groups 4 to <7 and 7 to <12) and receive desflurane. Nausea was not well documented and was therefore not analyzed.

CONCLUSION

The incidence of vomiting in children after posterior fossa surgery is sufficient to consider all children requiring these procedures to be at high risk for POV. Nausea requires better assessment and documentation.