To measure the OJ, a 40- mm ruler was used; to measure CC, a metric tape was placed at the cricothyroid membrane, and for AC, the same tape was used, after being placed at the umbilicus.10 Patients were submitted to polysomnography, accompanied by a parent or guardian, for at least 10 h, in a quiet environment, with appropriate temperature and lighting for the examination. This was performed during spontaneous Selleckchem U0126 sleep, with no prior sedation or sleep deprivation, avoiding stimulating foods (coffee, chocolate, soda, and black tea). Polysomnography
was conducted in a hospital setting, using Sonolab 620 computerized equipment (Medtron – Brazil), and the report was issued by the same observer. The following were recorded during the polysomnography: EEG (C4-A1, C3-A2, O2-A1, and O1-A2), electro-oculogram, electromyogram of anterior tibial and chin nerves, and electrocardiogram. Respiratory movements were assessed through thoracic and abdominal band, and SpO2 by pulse oximetry. An oronasal cannula and thermistor were used to measure nasal airflow, in addition to a microphone placed in the neck to record snoring. The American Thoracic Society11 provides the following definition and the following criteria for the apnea-hypopnea index (AHI) in children: it corresponds
to the sum of the number of obstructive and mixed apneas, and obstructive and mixed hypopneas; it must be expressed in events per hour; to calculate this number, the total sleep time must be used, and it is considered abnormal when AHI ≥ 1 event per hour of sleep. Hypopnea was defined as a reduction > 50% of the flow amplitude GSK2656157 purchase Casein kinase 1 associated with a microarousal and/or reduction > 3% of baseline oxygen saturation. As for the apnea index (AI), the following assumptions were
followed: the number of obstructive and mixed apneas (mixed apneas are initially central and can become obstructive at the end of the event), lasting at least two respiratory cycles, which was expressed as events per hour; for the calculation, the total sleep time must be used, and it is considered abnormal when AI ≥ 1 event per hour of sleep. Microarousal was defined as an abrupt change in the electroencephalogram frequency lasting 3 s, preceded by at least 10 s of sleep. Nocturnal desaturation was defined as patients who had more than 30% of total sleep time with peripheral oxygen saturation (SpO2) < 90%. The project was approved by the research ethics committee of the institution (Protocol 197; Opinion 98/2006). Parents or guardians signed the informed consent after agreeing to participate in the study. The SPSS statistical program (released 2012,USA) was used for data tabulation and analysis. Quantitative variables were expressed as mean ± standard deviation or median and interquartile range. Qualitative variables were expressed as absolute and relative frequencies. Student’s t-test for independent samples or the Mann-Whitney test was used to compare two means.