Post-repair laxative management in obstetric anal sphincter injury guidelines: A narrative review

BACKGROUND

Childbirth is a common factor which increases the risk of obstetric anal sphincter injuries (OASIS). Damage to the anal sphincters increases the risk of anal incontinence, which has a debilitating impact on the quality of life. Post-repair laxatives are prescribed in this group of women. However, there is no consensus regarding the type or frequency with which they are used, and available guidelines lack consistency and evidence to support the recommendations.

AIM

The aim was to review and compare the international, national and local Australian management guidelines for recommendations regarding laxative use in women after OASIS.

METHOD

An online literature search of medical and nursing databases such as PubMed, Embase, MEDLINE, CINAHL, Web of Science, Scopus and Cochrane was performed between January 2000 and October 2020. Full-text articles with MeSH headings and Text Words [TW] identified guidelines in the prevention, management and care of OASIS. The search terms included 'obstetric anal sphincter injury', 'OASIS', 'perineal tear', 'postpartum continence', 'bowel injury', 'aperient', 'laxative use' and 'bulking agents'.

RESULTS

Thirteen guidelines were included. Laxatives were recommended in most guidelines; however, there was a lack of consistency regarding the type of laxative used, frequency, dose and duration of use. Guidelines were based on historical evidence, with paucity of recently acquired data identified.

CONCLUSIONS

There is no consensus regarding an optimal laxative regime for women who sustain an anal sphincter injury after childbirth. Further research is required to develop evidence-based robust clinical guidelines regarding laxative use in women who sustain OASIS.

Utilisation and Safety of Polyethylene Glycol 3350 With Electrolytes in Children Under 2 Years: A Retrospective Cohort

OBJECTIVES

In the UK, Movicol paediatric plain (polyethylene glycol 3350 with electrolytes [PEG 3350+E], Norgine, UK), is licensed for chronic constipation in children 2 -11 years of age and faecal impaction (FI) from 5 years. This study aimed to investigate usage and characterise the risk profile in children under 2 years of age using PEG 3350+E in the UK.

METHODS

Retrospective, single exposure cohort study, with patients identified from Clinical Practice Research Datalink (CPRD) GOLD. Patients first prescribed PEG 3350+E under 2 years of age for the treatment of constipation or FI, between September 2003 and July 2019, were included.

RESULTS

There were 13,235 patients with a constipation indication and 40 patients with FI. For the constipation cohort: median age of PEG 3350+E first prescription was 1.2 years [interquartile range (IQR) 0.9, 1.6] and 68.4% had one treatment episode (TE). The mean duration of exposure, in the first TE, was 88.9 days. The most common total daily dose was one sachet (6.9 g).In terms of incident events on treatment, 0.5% of patients had abdominal pain, 3.0% had diarrhoea (may be attributed to treatment) and 4.1% had vomiting. 2.0% had signs/symptoms which could (in extreme cases) be associated with electrolyte disturbance, however, none had abnormal electrolyte values.

DISCUSSION

The safety aspect of this study did not identify any signals of concern in the constipation cohort. The number of patients in the FI cohort were too small for robust conclusions. If information were available, then a safety study would ideally assess treatment intake per kilogram, including electrolyte intake, before reaching safety conclusions. Nevertheless, these data contribute to real-world evidence on the use of PEG 3350+E in this population.

Augmentation with pre-emptive macrogol-based osmotic laxative does not significantly improve standard bowel preparation in unselected patients: A randomized trial

Background and Aim

The addition of a laxative prior to a standard bowel preparation (BP) has shown variable results in efficacy, safety, and tolerability of the BP. This study compared the efficacy and tolerability of a macrogol-augmented BP (M-BP) with standard BP for routine colonoscopy in unselected patients.

Methods

Adults undergoing outpatient colonoscopy were randomized to either M-BP (one sachet of macrogol-based osmotic laxative (MBOL) twice daily for eight doses prior to standard preparation) or BP (split-dose of polyethylene glycol and sodium picosulfate). Bowel cleansing was assessed using the Ottawa BP scale. Risk factors for poor BP, patient satisfaction, and tolerance were recorded.

Results

This randomized trial was stopped due to futility after 14 months; at that point, 92 subjects were randomized to the study arm and 102 to the control arm. M-BP had a success rate of 71.7% (95% CI: 58.5-82.7%), while the BP had a success rate of 67.7% (95% CI: 54.9-78.8%), with a Pearson χ ² test P-value of 0.639, which exceeded the cut-off for futility (0.313). In subgroup analyses, there were statistically significant decreases in the rates of successful BP in patients taking regular opioids and regular laxatives. Both preparations were well tolerated, with no difference between groups (BP - 5.3% and M-BP - 6.6% P = 0.66).

Conclusion

The addition of MBOL prior to a standard BP in unselected subjects does not significantly improve bowel cleanliness at routine colonoscopy. The role of this laxative in patients at high risk of poor preparation warrants further investigation.