Estudio de la vía aérea superior frente a apneas obstructivas del sueño persistentes en pediatría / An approach to the upper airway evaluation in pediatric persistent obstructive sleep apnea

El síndrome de apneas obstructivas del sueño (SAOS) en pediatría constituye un trastorno asociado a múltiples consecuencias en el espectro cognitivo y comportamental. El principal factor de riesgo asociado es la hipertrofia amigdalina y las vegetaciones adenoideas. La adenoamigdalectomía es el tratamiento de primera línea. La incidencia del SAOS persistente varía entre un 15 % y un 75 % según las comorbilidades. Este se presenta como un desafío a la hora de tratarlo; requiere un abordaje integral para su diagnóstico y tratamiento adecuado. El objetivo de esta revisión bibliográfica es proponer un abordaje diagnóstico y terapéutico para el SAOS persistente.

In pediatrics, obstructive sleep apnea syndrome (OSAS) is a disorder associated with multiple consequences at the cognitive and behavioral level. The main associated risk factor is the presence of tonsillar hypertrophy and adenoids. An adenotonsillectomy is the first-line treatment. The incidence of persistent OSAS varies from 15% to 75%, depending on comorbidities. This is a challenge in terms of management; it requires a comprehensive approach for an adequate diagnosis and treatment. The objective of this bibliographic review is to propose a diagnostic and therapeutic approach for persistent OSAS.

Avaliação do ventrículo esquerdo em pacientes com DPOC e hipoxemia noturna / Evaluation of the left ventricle in patients with COPD and nocturnal hypoxemia

RESUMO Objetivo Verificar a associação entre massa e espessura do ventrículo esquerdo (VE) e presença de hipoxemia noturna significativa em pacientes portadores de DPOC com hipoxemia diurna leve. Métodos Estudo transversal realizado em pacientes ambulatoriais, clinicamente estáveis, portadores de DPOC e hipoxemia leve (saturação de oxigênio ≥ 90 a ≤ 94%, identificados por oximetria não invasiva) em um centro clínico especializado no atendimento de doenças respiratórias em Goiânia (GO). Todos foram submetidos a avaliação clínica, espirometria, polissonografia, ecocardiografia, gasometria arterial, teste de caminhada de 6 minutos e radiografia de tórax. Resultados Foram avaliados 64 pacientes com DPOC e hipoxemia noturna. Pacientes com hipoxemia noturna significativa apresentaram parâmetros ecocardiográficos associados a mais quantidade de musculatura do VE quando comparados a pacientes com hipoxemia noturna leve. A relação entre volume/massa do VE foi significativamente menor no grupo com hipoxemia noturna significativa (0,64 ± 0,13 versus 0,72 ± 0,12; p = 0,04) e a espessura diastólica do septo interventricular e a espessura diastólica da parede posterior do VE foram significativamente maiores nesse grupo (9,7 ± 0,92 versus 9,1 ± 0,90; p = 0,03) (9,7 ± 1,0 versus 8,9 ± 1,0; p = 0,01). O tempo de sono REM com saturação abaixo de 85% prediz significativamente a espessura do septo (ajuste para índice de massa corporal [IMC], idade e pressão arterial média; r2 = 0,20; p = 0,046). Conclusão Em indivíduos portadores de DPOC e hipoxemia noturna significativa, foi observada associação entre hipoxemia severa no sono REM e parâmetros ecocardiográficos que indicam aumento da massa do VE. Tal fato sugere que esse subgrupo de indivíduos pode se beneficiar de uma avaliação ecocardiográfica do VE.

ABSTRACT Objective To verify association between left ventricular (LV) mass and thickness and the presence of significant nocturnal hypoxemia in patients with COPD with mild diurnal hypoxemia. Methods A cross-sectional study carried out in clinically stable outpatients with COPD and mild hypoxemia (oxygen saturation ≥90 to ≤94%, identified by noninvasive oximetry) in a clinic specialized in the treatment of respiratory diseases in Goiânia-GO. All patients were submitted to clinical evaluation, spirometry, polysomnography, echocardiography, arterial blood gas analysis, 6-minute walk test and chest X-ray. Results Patients with significant nocturnal hypoxemia had echocardiographic parameters associated with increase of LV musculature when compared to patients with mild nocturnal hypoxemia. The LV volume/mass ratio was significantly lower in the group with significant nocturnal hypoxemia (ratio 0.64 ± 0.13 versus 0.72 ± 0.12, p = 0.04), the thickness diastolic diameter of the interventricular septum and the diastolic thickness of the LV posterior wall were significantly higher in this group (9.7 ± 0.92 versus 9.1 ± 0.90 p = 0.03), (9.7 ± 1.0 versus 8.9 ± 1.0, p = 0.01. The time in REM sleep with saturation below 85% significantly predicted septum thickness (adjustment for BMI, age and mean blood pressure, r2 = 0.20; p = 0.046). Conclusion We observed association between severe REM sleep hypoxemia and echocardiographic parameters indicating increased LV mass in individuals with COPD and significant nocturnal hypoxemia. This suggests that this subgroup of individuals may benefit from an echocardiographic evaluation of the left ventricle.

A negative expiratory pressure test during wakefulness for evaluating the risk of obstructive sleep apnea in patients referred for sleep studies

OBJECTIVE: Obstructive sleep apnea is characterized by increased upper airway collapsibility during sleep. The present study investigated the use of the negative expiratory pressure test as a method to rule out obstructive sleep apnea. METHODS: Flow limitation was evaluated in 155 subjects. All subjects underwent a diurnal negative expiratory pressure test and a nocturnal sleep study. The severity of sleep apnea was determined based on the apneahypopnea index. Flow limitation was assessed by computing the exhaled volume at 0.2, 0.5, and 1.0 s (V0.2, V0.5, and V1.0, respectively) during the application of a negative expiratory pressure and expressed as a percentage of the previous exhaled volume. Receiver-operating characteristic curves were constructed to identify the optimal threshold volume at 0.2, 0.5, and 1.0 s for obstructive sleep apnea detection. RESULTS: Mean expiratory volumes at 0.2 and 0.5 s were statistically higher (p <0.01) in healthy subjects than in all obstructive sleep apneic groups. Increasing disease severity was associated with lower expiratory volumes. The V0.2 ( percent) predictive parameters for the detection of sleep apnea were sensitivity (81.1 percent), specificity (93.1 percent), PPV (98.1 percent), and NPV (52.9 percent). Sensitivity and NPV were 96.9 percent and 93.2 percent, respectively, for moderate-to-severe obstructive sleep apnea, and both were 100 percent for severe obstructive sleep apnea. CONCLUSION: Flow limitation measurement by V 0.2 ( percent) during wakefulness may be a very reliable method to identify obstructive sleep apnea when the test is positive and could reliably exclude moderate and severe obstructive sleep apnea when the test is negative. The negative expiratory pressure test appears to be a useful screening test for suspected obstructive sleep apnea.

Evolución clínica y de laboratorio en lactantes con inmadurez del centro respiratorio que presentan episodios de apnea / Apnoea in infancy: clinical and laboratory characteristics

Los episodios de apnea y de pausa respiratoria son eventos comunes que se presentan en recién nacido sy lactantes 1. Las pausas respiratorias pueden ser normales a diferentes edades, sin embargo, deben ser consideradas anormales si son mayores a 20 segundos de duración o si producen hipoxemia o cianosis asociada 2,3. Una parte significativa de la susceptibilidad de los lactantes menores a presentar apnea y pausas respiratorias, se relaciona al desarrollo del control de la respiración que ocurre dentro de los primeros meses de la vida.