Question

• A seven-year-old boy with nocturnal enuresis and obstructive sleep apnea undergoes surgery to relieve upper airway obstruction and his nocturnal enuresis resolves. Another seven-year-old boy presents to the clinic for a well-child examination, where his mother brings up her frustration with her sons nightly bedwetting. Should I ask about and evaluate for obstructive sleep apnea or upper airway obstruction as a potential etiology or association? In children with nocturnal enuresis, should the possibility of coexisting obstructive sleep apnea be relevant to my clinical history, evaluation, and treatment options?

Clinical Bottom Lines

1. Only case reports and case series of associations between nocturnal enuresis and upper airway obstruction in children and adults are available.
2. Weider et al. demonstrates all-or-none case series evidence (level Ia, grade A) that in children with secondary enuresis (onset equivalent to onset of symptoms of obstructive sleep apnea), additional history regarding coexisting sleep apnea should be sought.¹
3. Although the level of evidence is poor (level III, grade C), in children with primary enuresis, history obtained should probably include symptoms of obstructive sleep apnea.
4. The case series study by Weider et al. demonstrates the need for further randomized controlled trials to evaluate the association between nocturnal enuresis and obstructive sleep apnea.

Summary of Key Evidence

1. In Weider et al.'s case series report, 115 children between the ages of 3 and 19 with symptoms of upper airway obstruction, obligate nighttime mouth breathing, and nocturnal enuresis were evaluated.¹ 
2. Preoperatively, the children in the study had 5.6 enuretic nights each week.
3. All children in the study underwent surgical procedures for relief of upper airway obstruction; 111/115 had tonsillectomy/adenoidectomy.
4. Children were followed for 12 months after surgery.
5. At 1 month, there was a 66% reduction in the number of enuretic nights each week; at 6 months, there was a 77% reduction in the number of enuretic nights each week. This reduction remained constant through the 12 month follow-up period.
6. Of 12 children with secondary enuresis (onset of enuresis equivalent to onset of symptoms of upper airway obstruction), all had stopped bedwetting at 6 months and remained free of enuretic events through 12 months.

Additional Comments

• In critically appraising topics, studies of all designs (systematic reviews, randomized controlled trials, case-controlled studies, case series, etc.) will be encountered. If “grade A” evidence is not available, less ideal levels of evidence can still be applicable and relevant, perhaps with a “lower grades” of recommendation.
• Nocturnal enuresis occurs in 15-20% 5 year olds, and its occurrence steadily (15%/year) decreases with increasing age; this spontaneous resolution of enuresis complicates all studies that attempt to follow it longitudinally.
• The true prevalence of obstructive sleep apnea in children is also difficult to identify; the lowest estimate is 2.9%.²
• Biologically, an association between airway obstruction and nocturnal enuresis could exist for several reasons. Obstructive sleep apnea interrupts sleep and may limit normal arousal and self alerting mechanisms. Hormonal change (obstructive sleep apnea and lower levels of ADH) and increased intra-abdominal pressure have also been suggested as possible factors.

Citation

1. Weider D, Sateia M, and West R. Nocturnal enuresis in children with upper airway obstruction. Otolaryngology—Head and Neck Surgery, 1991; 105:427-432.
2. Wang R, Elkins T, Keech D, Wauquier A, and Hubbard D. Accuracy of clinical evaluation in pediatric obstructive sleep apnea. Otolaryngology—Head and Neck Surgery, 1998; 118:69-73.

CAT Author: Megan Clipp, MD

CAT Appraisers: Robert Schumacher , MD

Date appraised: August 28, 2000