Nocturnal hypoxemia, but not hypercapnia, correlates with sleep quality in children.

BACKGROUND A correlation has been observed between obstructive sleep events and sleep quality. The aim of the study was to assess if there is also a correlation between nocturnal hypoxemia and hypercapnia and sleep efficiency and sleep fragmentation in children. METHODS Nocturnal pulse oximetry (S(pO(2))) and transcutaneous carbon dioxide (P(tcCO(2))) recordings with simultaneous actigraphy were performed in 38 children with nocturnal hypoxemia and hypercapnia during spontaneous breathing (nocturnal hypoventilation [NH] group), 25 children with partially corrected nocturnal hypoventilation (PC-NH group), and 11 subjects with normal nocturnal gas exchange (no-NH group). RESULTS Sleep efficiency and sleep fragmentation on actigraphy correlated with minimal S(pO(2)) (r(2) = 0.21, P = .004, and r(2) = -0.10, P = .050, respectively) and the percentage of night time with S(pO(2)) < 90% (r(2) = -0.33, P < .001, and r(2) = 0.13, P = .028, respectively) in the NH group. Sleep efficiency and sleep fragmentation also correlated with pulse rate standard deviation (r(2) = -0.42, P < .001, and r(2) = 0.37, P < .001, respectively). No correlation was observed between sleep efficiency and sleep fragmentation and P(tcCO(2)). No correlation was observed between sleep efficiency and sleep fragmentation and S(pO(2)), P(tcCO(2)), and pulse rate in the PC-NH group. Sleep efficiency, sleep fragmentation, and nocturnal S(pO(2)), and P(tcCO(2)) were all normal and not correlated in the no-NH group. CONCLUSIONS In children with nocturnal hypoventilation, nocturnal hypoxemia but not hypercapnia correlates with sleep efficiency and sleep fragmentation on actigraphy.