Tonsillectomy in Pediatric Patients with Sleep Disorderd Breathing

The prevalence of pediatric obstructive sleep apnea is estimated to be between one and three percent in preschool and school-age children. Sleep-disordered breathing for these young patients can range from partial obstruction of the upper airway (producing snoring) to increased upper airway resistance syndrome to continuous episodes of complete upper airway obstruction or OSA. Tonsillectomy and adenoidectomy (T&A) has been proven to be successful in eliminating obstruction in 85-95 percent of otherwise normal children with obstructive sleep apnea.

While the effects of obstructive sleep apnea on children are well recorded, there is confusion and inaccuracy related to predicting which children will have a positive polysomnography (PSG), the overnight sleep study, a key indicator for OSA. In seven previous trials, the accuracy of clinical evaluation of pediatric OSA predicting a positive sleep study was poor, ranging from 30 to 85 percent. Insofar that research has established that 20-30 percent of snoring children have a positive PSG, numerous medical authorities recommend that a PSG be obtained prior to a tonsillectomy to differentiate primary snoring from obstructive sleep apnea.

However, problems remain with establishing an appropriate course of action for children with sleep disordered breathing. First, past research claiming that sleep studies fail to provide an accurate evaluation of OSA in children used adult criteria in interpretation of PSG results. Additionally, none of the past research studies considered the diagnosis of upper airway resistance syndrome in PSG evaluations, a task that requires esophageal pressure monitoring and is not available in most sleep study centers.

Children presenting a clinical assessment suggestive of OSA yet with a negative PSG finding provide a dilemma to the specialist treating a child with sleep-disordered breathing. Essentially, the sleep study has been considered the "gold standard" diagnostic tool determine which children with upper airway obstruction would benefit from a tonsillectomy and adenoidectomy. Yet, numerous prior reports have shown that children's upper airway obstruction symptoms improve after T&A regardless of whether a child's apnea is documented by a PSG.

A team of specialists set out to determine whether otherwise healthy children with a clinical assessment of significant upper airway obstruction but with a PSG negative for OSA have improvement after tonsillectomy/adenoidectomy as compared to children who do not undergo surgery. The authors of the study, "The Clinical Assessment of Pediatric Obstructive Sleep Apnea," are Nira A. Goldstein MD, Andrew C. Goldman MD, Vasanthi Pugazhendhi MD, Madu Rao MD, Alex Sternberg ScD, Sudha M. Rao MD, and Jeremy Weedon PhD, all from the State University of New York Downstate Medical Center, Brooklyn, NY; Thomas F. Campbell PhD, from the Children's Hospital of Pittsburgh, J. Christopher Post MD, at Allegheny General Hospital, both in Pittsburgh, PA. Their findings were presented at the 18th annual meeting of the American Society of Pediatric Otolaryngology http://www.aspo.us/ , meeting May 4-5, 2003, at the Gaylord Opryland Hotel, Nashville, TN.

If the study found that children with a clinical assessment of pediatric obstructive sleep apnea but with a negative PSG finding do not improve with observation alone, then the clinician's role in diagnosing significant upper airway obstruction is correct.

Methodology: Fifty-nine children, between age two and 14, with a clinical diagnosis of obstructive sleep apnea were prospectively evaluated by a standardized history, physical examination, voice recording, review of tape recording of breathing during sleep, lateral neck radiograph to assess adenoid size, and echocardiogram to evaluate for pulmonary hypertension. The PSG (sleep study) was then applied to confirm the presence or absence of sleep apnea. Children with a positive PSG underwent a tonsillectomy and adenoidectomy; those with a negative PSG finding were randomized with one half receiving the surgery, the other half, not. The children would be assessed six months later with another PSG.

The PSG consisted of respiratory rate, pulse rate, pulse oximetry, inductive plethysmography of the chest and chest and abdomen, and oronasal airflow from a loose mask or oral/nasal thermistors. Obstructive sleep apnea was defined as the cessation of oronasal airflow with continued respiratory effort for at least 2.5 times the typical breath interval. Obstructive hypopnea was defined as a decrease in amplitude of oronasal airflow of at least 50 percent with no decrease in respiratory effort for the same duration. The PSG was considered positive for OSA if five obstructive apneas plus hypopneas per hour of sleep occurred, or at least ten percent of the night was spent with oxygen saturation less than 90 percent.

Results: Fifty-six children underwent a PSG. Twenty-seven (48 percent) had positive PSG; 29 (52 percent) registered a negative finding. Of the 29 children with negative PSG, 15 were randomized to T&A and 14 were selected not to have surgery. The parents of three children with a positive PSG score and parents of two children with a negative PSG finding, assigned to surgery, declined to have their children undergo the surgical procedure. Thirteen of the 56 children were lost to follow-up before the final study visit due to administrative reasons.

Accordingly, follow-up was available for 11 patients with negative PSG, randomized to undergo a tonsillectomy/adenoidectomy and nine non-surgery patients. The mean age of the children completing the protocol was between 5.8 and seven years. There were an almost equal number of boys and girls in the study with more girls with negative PSG randomized to surgery and more boys with negative PSG randomized for no surgery.

Follow-up revealed that of the 11 negative PSG patients who underwent a T&A, nine were asymptomatic compared with two of the nine who did not have surgery.

Conclusions: The PSG or sleep study has been recommended to differentiate children with primary snoring (snoring without apnea) who do not have other nighttime and daytime symptoms and have normal sleep study results, as compared to the pediatric patient with obstructive sleep apnea. Primary snoring is considered to be a benign condition, resolving by itself in 50 percent of children over time, and progressing to mild obstructive sleep apnea in ten percent of patients. Conventional wisdom was that children with a negative PSG be not considered for surgical treatment of upper-airway obstruction even if symptoms related to enlarged tonsils and adenoids are present.

This study demonstrates that otherwise healthy children with a clinical assessment suggestive of obstructive sleep apnea benefit from tonsillectomy and adenoidectomy, even if the PSG is normal. The authors believe that until a non-invasive, reliable test for sleep disordered breathing is available, the clinical evaluation remains an essential tool in determining the need for surgical intervention.