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.