title: Ambulatory blood pressure before and after adenotonsillectomy in children with obstructive sleep apnea.
abstract: BACKGROUND
  Hypertension is found to be associated with obstructive sleep apnea (OSA) in both children and adults. But data on the effect of blood pressure after adenotonsillectomy (AT) for children with OSA are limited and controversial.
  
  
  OBJECTIVE
  To assess the impact of AT on different parameters of 24-h ambulatory blood pressure monitoring in children with OSA.
  
  
  METHODS
  We retrospectively reviewed records of OSA children who had undergone AT and a repeated sleep polysomnography after AT from 2001 to 2008.
  
  
  RESULTS
  Forty-four children were identified and included in the analysis. The mean apnea-hypopnea index (AHI) dropped from 14.14+/-15.9 to 3.3+/-7.1. (p<0.001). Twenty (45%) were cured of OSA. After AT, the diastolic BP load decreased significantly. Six out of eight (75%) hypertensive children became normotensive after surgery. For the pre-AT hypertensive group, both systolic and diastolic blood pressure decreased significantly during sleep after AT. However, eight children who were normotensive before AT became hypertensive after AT. These 10 post-AT hypertensive patients were more likely to have post-AT AHI>1 than the post-AT normotensive group, although the difference did not reach statistical significance.
  
  
  CONCLUSIONS
  In the current cohort of OSA children, 44% were cured of OSA and a significant decrease in overall diastolic blood pressure load in 24-h ambulatory blood pressure was achieved after adenotonsillectomy for children with OSA. But hypertension may persist or even occur in those previously normotensive children despite the improvement in AHI. Persistence of OSA may be a risk factor and further study is required. Cure of OSA should not be assumed after AT and follow-up PSG should be performed together with 24-h ambulatory blood pressure monitoring. In light of the current findings, long term study of the blood pressure is warranted for children with OSA.
authors.affiliation: Department of Paediatrics, Kwong Wah Hospital, Hong Kong. dkkng@ha.org.hk
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Ng
authors.forename: Jeff C
authors.initials: JC
authors.lastname: Wong
authors.forename: Chung-Hong
authors.initials: CH
authors.lastname: Chan
authors.forename: Lettie C K
authors.initials: LC
authors.lastname: Leung
authors.forename: Shuk-Yu
authors.initials: SY
authors.lastname: Leung
mesh_terms: D000233:Adenoidectomy; D000293:Adolescent; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D011184:Postoperative Period; D057234:Preoperative Period; D012189:Retrospective Studies; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000453:epidemiology / Q000601:surgery*; D014068:Tonsillectomy