Nasal continuous positive airway pressure reduces sleep-induced blood pressure increments in preeclampsia

Preeclampsia is the predominant cause of admissions to neonatal intensive c are. The diurnal blood pressure pattern is flattened or reversed in preecla mpsia. We hypothesized that snoring and partial upper airway obstruction co ntribute to nocturnal rises in blood pressure. We tested this hypothesis by controlling sleep-induced upper airway flow limitation and snoring with na sal positive pressure. Eleven women with preeclampsia underwent two consecu tive polygraphic sleep studies with simultaneous beat-to-beat blood pressur e monitoring. Average blood pressure for the night overall and in each slee p stage was calculated. Sleep architecture was similar on the two study nig hts. Sleep-induced partial upper airway flow limitation occurred in all pat ients in the initial study. Autosetting nasal continuous positive airway pr essure (CPAP) applied at a mean maximal pressure of 6 +/- 1 cm H2O eliminat ed flow limitation throughout sleep on the treatment night. Blood pressure was markedly reduced on the treatment night [(128 +/- 3)/(73 +/- 3)] when c ompared with the initial nontreatment study night [(146 +/- 6)/(92 +/- 4)], p = (0.007)/(0.002). We conclude that partial upper airway obstruction dur ing sleep in women with preeclampsia is associated with increments in blood pressure, which can be eliminated with the use of nasal CPAP.