El diagnóstico del síndrome de apneas/hipoapneas del sueño (SAHS), se establece en función de manifestaciones clínicas y registros polisomnográficos (PSG) nocturnos. Como alternativa a la PSG nocturna completa, se han propuesto estudios nocturnos abreviados.

Determinar si la corrección de la PSG de la primera mitad de la noche es suficiente para establecer el diagnóstico de SAHS y analizar la correlación existente entre las variables polisomnográficas de los registros de 4 h (mitad del estudio) frente a los de ocho horas de duración (estudio completo), así como determinar la coincidencia diagnóstica.

Se estudian de forma prospectiva 35 pacientes con sospecha clínica de SAHS, a los que se realiza un estudio polisomnográfico basal nocturno, corregido de forma ciega por dos observadores diferentes, según los métodos estándar. El diagnóstico de SAHS, se realiza según la normativa de la Sociedad Española de Neumología y Cirugía Torácica (SEPAR). En la primera mitad y al final del estudio PSG se recogen variables neurofisiológicas, respiratorias y la impresión diagnóstica.

La correlación encontrada entre las diferentes variables consideradas (estadios de sueño, índice de apnea/hipoapnea [IAH] global, IAH REM, IAH no REM y eficiencia del sueño) entre la mitad (MN) y el estudio PSG completo (TN) es significativa para un valor de p < 0,05, tanto al aplicar el coeficiente de correlación de Pearson (r) como al aplicar el coeficiente de correlación intraclase (CCI). La coincidencia diagnóstica se produjo en 33 de los 35 pacientes estudiados (94,3%; intervalo de confianza [IC] del 95%: 80,84-99,30), siendo del 100% en el caso de los SAHS severos.

Sobre la base de los resultados obtenidos, concluimos que los pacientes con diagnóstico de SAHS severo en la primera mitad de la noche son subsidiarios de estudios de titulación en la segunda mitad de la noche.

A diagnosis of sleep apnea/hypopnea syndrome (SAHS) is based on clinical signs and nighttime polysomnograms. Brief polysomnography has been proposed as an alternative to all-night recording.

The aim of this study was to determine whether a polysomnograms obtained during the first half of the night is sufficient for establishing a diagnosis of SAHS and to determine the correlation between polysomnographic variables recorded during the first four hours (half the study time) with those recorded over the full eight hours (full study time), as well as to determine diagnostic agreement.

Thirty-five patients suspected of having SAHS were studied prospectively. Baseline polysomnograms were scored blindly by two independent observers following standard methods. A diagnosis of SAHS was made according to guidelines of the Spanish Society of Pneumology and Chest Surgery. During the first half of the night and up to the end of each recording period we gathered neurophysiological and respiratory variables and diagnostic impressions.

The correlation between variables (sleep stage, overall AHI, REM-AHI, non-REM-AHI and sleep efficiency) recorded in the first half of the night and throughout the night was significant (p < 0.05) by both Pearson's correlation coefficient (r) and by the intraclass correlation coefficient (ICC). In 33 of 35 patients (94.3%) diagnostic agreement was achieved (95% CI 80.84-99.30); when SAHS was severe, agreement was 100%.

Based on these results, we conclude that for patients with a diagnosis of severe SAHS during the first half of the night, data recorded during the second half can be considered supplementary.