Autoregulation versus defaecation: An unusual side effect of CPAP (2014)

Type of publication:
Conference abstract

*Stone H., *Fazal F., *Moudgil H., *Ahmad N., *Naicker T., *Srinivasan K.

European Respiratory Journal, September 2014, vol./is. 44 (Suppl 58)

Introduction Continuous Positive Airway Pressure is the first line treatment for symptomatic moderate to severe obstructive sleep apnoea. Side effects of CPAP are well known; however faecal incontinence secondary to CPAP is not documented. We present the case of a patient with OSA who developed this on commencing CPAP. Case A 50 year old female with ulcerative colitis had a total colectomy in 1992 and a subsequent ileo-anal pouch reconstruction. She was referred to the sleep clinic as she was experiencing daytime somnolence (Epworth score of 15/24). Her sleep study demonstrated severe obstructive sleep apnoea with an apnoea-hypopnoea index of 35.2, and for 12.5% of the study, her Sa02 were below 90%. She was commenced on CPAP using auto titration. Initially, she experienced problems with faecal leakage – defecating up to 4 times per night. During this time her mean CPAP pressure had been 17cm water. She was subsequently converted CPAP at 10cms fixed maximum pressure and now tolerates CPAP very well; having a degree of faecal leakage only 2 or 3 times a week, rather than every night as previously. Her Epworth score has now fallen to 9/24, her AHI is 2.5 and her OSA symptoms have improved, leading to better treatment compliance. Conclusion It was hypothesised that the patient’s problems were related to increased intra-thoracic pressure from the CPAP, resulting in raised intra-abdominal pressure, putting a strain on the ileo-anal pouch reconstruction giving rise to the faecal incontinence. This resolved with lower CPAP pressures, resolving the faecal frequency whilst still adequately treating the OSA. Limiting pressures should be considered in the future in patients with colorectal disease to avoid faecal incontinence.

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