Triological Society Best Practice
Is polysomnography required prior to tonsillectomy and adenoidectomy for diagnosis of obstructive sleep apnea versus mild sleep disordered breathing in children?
Polysomnography (PSG) has been recommended by the American Academy of Pediatrics1 as the gold standard for the diagnosis of obstructive sleep apnea (OSA) versus mild sleep disordered breathing (SDB) prior to tonsillectomy and adenoidectomy (T+A) in children. Mild SDB includes primary snoring and upper airway resistance syndrome. Controversy exists regarding the accuracy of history and physical exam (H+P) alone in children for the diagnosis of OSA versus mild SDB prior to T+A.2 Thus, PSG has been recommended to confirm the diagnosis.1 However, controversy also exists regarding the value of PSG in children, because different sleep centers use different equipment and different criteria for defining positive studies for OSA. This variability in PSG studies often makes it difficult to clearly interpret PSG results.3
A meta-analysis by Brietzke and colleagues2 included 12 publications concerning the accuracy of H+P compared to PSG for the diagnosis of OSA versus mild SDB in children. These authors concluded that 11 of 12 studies showed that H+P was not accurate for the diagnosis of OSA versus mild SDB, and that PSG is required prior to T+A in children. However, a review by Ray and Bower3 presented an opposing view and discussed that four of these 12 studies (references 2, 5, 8, 9 in Brietzke et al.2) used the adult criteria for a positive PSG defined as an apnea/hypopnea index of ≥5/hour rather than the pediatric criteria of ≥1/hour, one study had no specified criteria (reference 10 in Brietzke et al.2), and one study was not controlled (reference 7 in Brietzke et al.2). Therefore, six of these 11 studies may not have correctly correlated H+P findings with PSG data. PSG is also time consuming, expensive, and often not available. Sources of variability in PSG studies in children include: 1) use of nasal air flow thermister versus pressure sensor, 2) definition of hypopnea as 50% reduction in air flow with arousal or desaturation versus 30% reduction in air flow with arousal or desaturation, 3) some centers do not measure end-tidal CO2 to confirm or exclude hypoventilation, and 4) some centers do not differentiate between central versus obstructive apneas. Thus, the rate of positive PSG studies in children may vary depending on equipment and criteria used.3
Mild SDB without true OSA has been shown to often carry the same morbidity as OSA in children, including daytime somnolence, behavioral changes, and poor school and cognitive performance.4 Additionally, the outcomes following T+A for OSA versus mild SDB in children are the same, with significant improvements in these morbidities for both groups. This improvement is independent of severity of PSG findings.4 These similarities make the need to obtain PSG less important for distinguishing between OSA versus mild SDB in symptomatic children.
A survey of the members of the American Society of Pediatric Otolaryngology reported that 75% of members obtained PSG prior to T+A in children with obstructive symptoms in less than 10% of patients, and that 64% proceeded with T+A without PSG.5 However, selected groups of children are recommended to have PSG prior to T+A.5 These include children suspected of having severe OSA, such as those with craniofacial syndromes, morbid obesity, neuromuscular disorders, and children <3 years of age. The diagnosis of severe OSA alerts the surgeon to place the child in the intensive care unit postoperatively for monitoring and treatment. Additionally, children who are at increased risk for anesthesia and surgery should have PSG performed prior to T+A, because a normal PSG may allow avoidance of the risk of surgery. This includes children with significant comorbidities, such as cardiac or pulmonary disease.
Even with preoperative PSG data, it may be difficult to predict which patients will have postoperative complications. Postoperative admission for monitoring and treatment of complications, such as desaturations and apneas, is appropriate for at-risk children following T+A. This approach also makes preoperative PSG unnecessary.
For otherwise healthy children with a history consistent with nighttime snoring; restlessness; daytime symptoms, including somnolence, behavioral changes, and poor cognitive performance; and a physical exam consistent with adenotonsillar hypertrophy, with or without witnessed apnea, it is reasonable to proceed with T+A without prior PSG.3 Preoperative PSG is needed when the child has medical comorbidities, age <3 years, or small tonsils and adenoids, and the physical findings do not correlate with the degree of airway obstruction.5
LEVEL OF EVIDENCE
For reference 1, the evidence-based medicine (EBM) level for a clinical guideline was not classified. For reference 2, the EBM level for the 12 studies ranged from 1 to 4, with an overall level of 2. For reference 3, the EBM level for a review was not classified. For reference 4, the EBM level was 1. For reference 5, the EBM level was 4. Overall, the low level of evidence in the literature suggests that additional well-controlled prospective studies are required to further clarify the value of H+P versus PSG for the diagnosis of OSA versus mild SDB, and to clarify the outcomes of T+A in these children.