Development of a pediatric obstructive sleep apnea triage algorithm.

INTRODUCTION: Diagnosis and treatment of obstructive sleep apnea (OSA) in children is often delayed due to the high prevalence and limited physician and sleep testing resources. As a result, children may be referred to multiple specialties, such as pediatric sleep medicine and pediatric otolaryngology, resulting in long waitlists. METHOD: We used data from our pediatric OSA clinic to identify predictors of tonsillectomy and/or adenoidectomy (AT). Before being seen in the clinic, parents completed the Pediatric Sleep Questionnaire (PSQ) and screening questionnaires for restless leg syndrome (RLS), nasal rhinitis, and gastroesophageal reflux disease (GERD). Tonsil size data were obtained from patient charts and graded using the Brodsky-five grade scale. Children completed an overnight oximetry study before being seen in the clinic, and a McGill oximetry score (MOS) was assigned based on the number and depth of oxygen desaturations. Logistic regression, controlling for otolaryngology physician, was used to identify significant predictors of AT. Three triage algorithms were subsequently generated based on the univariate and multivariate results to predict AT. RESULTS: From the OSA cohort, there were 469 eligible children (47% female, mean age = 8.19 years, SD = 3.59), with 89% of children reported snoring. Significant predictors of AT in univariate analysis included tonsil size and four PSQ questions, (1) struggles to breathe at night, (2) apneas, (3) daytime mouth breathing, and (4) AM dry mouth. The first triage algorithm, only using the four PSQ questions, had an odds ratio (OR) of 4.02 for predicting AT (sensitivity = 0.28, specificity = 0.91). Using only tonsil size, the second algorithm had an OR to predict AT of 9.11 (sensitivity = 0.72, specificity = 0.78). The third algorithm, where MOS was used to stratify risk for AT among those children with 2+ tonsils, had the same OR, sensitivity, and specificity as the tonsil-only algorithm. CONCLUSION: Tonsil size was the strongest predictor of AT, while oximetry helped stratify individual risk for AT. We recommend that referral letters for snoring children include graded tonsil size to aid in the triage based on our findings. Children with 2+ tonsil sizes should be triaged to otolaryngology, while the remainder should be referred to a pediatric sleep specialist.

Separation of the erythropoietin-responsive progenitors BFU-E and CFU-E in mouse bone marrow by unit gravity sedimentation.

The sedimentation velocity profiles of the entities in mouse bone marrow responsible for erythropoietic burst formation (BFU-E) and for erythrocytic colony formation (CFU-E) have been studied under conditions designed to determine whether the values observed are real or result from cell interactions occurring during culture of the fractions. Bone marrow cells of adult C3Hf/Bi mice were subjected to unit gravity sedimentation in a bovine serum albumin gradient, and fractions were assayed in plasma culture. Because it was found that cell concentration affected the efficiency of erythropoietic burst formation in culture, aliquots were plated at two different cell concentrations, as well as at a fixed proportion of each fraction. The modal sedimentation velocity of the BFU-E population averaged 3.9 mm/hr and that of the CFU-E population, 6.4 mm/hr; both were found to be independent of cell concentration or method of dividing the fractions. Cells from fractions of different sedimentation velocity were mixed with one another or with unfractionated cells. No significant inhibition or stimulation of erythropoietic burst formation was seen. We concluded that the observed values represented the true modal sedimentation velocities of BFU-E and cfu-e in normal mice. To determine whether a change in the physiologic state of the animals affected the sedimentation velocities of BFU-E or CFU-E, marrow cells from mice hypertransfused with red cells were compared with those from controls. The modal sedimentation velocity of BFU-E was unaffected by hypertransfusion, nor was there any change in the number of BFU-E under these conditions. The number of CFU-E was substantially reduced without a significant change in modal sedimentation velocity.