N-acetylcysteine (NAC) is used to treat various types of bowel obstruction in children but evidence of efficacy is lacking. The formulations used are unlicensed and the dosing information in the British National Formulary for Children does not cover all the situations in which it may be required. This audit was undertaken to identify why, when and how this drug is used in a children's hospital.

Method A literature search was conducted to identify the evidence base for this treatment and then a retrospective audit of all patients who received NAC for bowel obstruction between January 2012 and December 2012 was undertaken. Suitable patients were identified using the JAC dispensing system and data extracted from prescriptions and medical notes using a standardised data collection form. Data collated included age, indication for NAC, dose, route, duration and the outcome of treatment. A positive outcome was determined to be the ability to tolerate feeds at the end of treatment without adverse effects. Data was analysed using descriptive statistics.

Results 15 patients received NAC during this period; insufficient data was available for 2 patients who were therefore excluded from the audit. Patients who received NAC ranged from newborn to two years old (mean 12 weeks, median 6 weeks of age). Abdominal distension was the only adverse effect identified. Cystic Fibrosis (CF) was the most common underlying diagnosis. Of the 5 CF patients, 2 required repeated courses of NAC whilst the 8 patients without CF received only one treatment episode each. The mean duration of treatment was slightly shorter in CF patients (range: 2–18 days, mean: 10.4 days) compared to those without CF (range: 5–26 days, mean: 13 days). Two patients, one with CF, remained on NAC at the end of the study period. Treatment for those with CF usually stopped when the patient was tolerating 30 mL boluses of enteral feeds (the threshold for starting Creon supplementation). The end point for those without CF was less definitive and the courses generally longer. Two patients without CF did not manage to tolerate feeds after using NAC and remained on TPN.

Conclusion This audit has shown that NAC is used for a variety of types of bowel obstruction in children. Dosing regimes were variable and in this audit the highest dose administered was associated with an adverse effect. The criteria for stopping NAC via different routes and for non-CF patients is poorly defined and may contribute to the overall increased course length in these patients. There is a need for randomised controlled trials to identify whether this treatment is effective and, if so, the optimal regimen to use.