POLYSOMNOGRAPHIC FINDINGS AT DISICHARCE IN INFANTS BORN AT LESS THAN 32 WEEKS CESTATIONAL AGE (GA)

Abstract

Premature infants, particularly survivors of respiratory distress syndrome (RDS), have an increased incidence of sudden infant death syndrome (SIDS). Also, infants who had an episode of aborted SIDS often have abnormal polysomnographic recordings. To determine whether these abnormalities are present in premature infants at discharge from hospital, we recorded chest and abdominal circumference, respired CO₂, skin surface PO₂ (P_sO₂) and PCO₂ (P_sCO₂), ECG, and esophageal pressure (P_es) in 25 infants born at less than 32 weeks of GA. Fourteen infants had RDS defined by clinical and radiological criteria [GA=28 ± 2, birth weight (BW)=1033 ± 265gr,age= 10.8 ± 6 weeks], and 11 had no RDS (GA=30.8 ± 1.3, BW=1250 ± 128, age=6.7 ± 2.4 weeks). Our results show an increased frequency of obstructive apnea (OA), defined as absence of respired CO₂ signal in the presence of respiratory effort; and either a >10 torr decrease in P_sO₂, a heart rate <120, or a P_es <-30 torr; in the RDS group (4.9 vs. 1.9 OA/n, P<0.05). Also, more OA episodes were associated with bradycardia in this group (1.9 vs. 0.4 episodes/h, P<0.10). Both central apnea (CA), defined as absence of both respired CO₂ and respiratory effort for more than 10 s, and periodic breathing (PB) occurred with a similar frequency in both groups (0.2 vs. 0.4 CA/h, 9.8 vs. 16.9% PB, in the RDS and NO RDS groups, respectively), in spite of a lower baseline P_sO₂ in the RDS group (67.7 ± 9.7 vs. 59.2 ± 7.9 torr, P<0.05). These findings suggest that infants born at less than 32 weeks of GA have significant sleep abnormalities which may only be detectable by means of polygraphic recordings. OA is particularly frequent in this group, and its association with serious apnea at home needs to be established.

Supported by NHLBI SCOR HL-27356 and ALA 57002

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD