Childhood Adenotonsillectomy Trial

1.1 Overview

Systolic and diastolic BP will be continuously monitored (every 30 minutes) using an automated oscillometric monitor (model 90207; Spacelabs Inc., Redmond, Washington, USA) over a 24 hour period on 2 occasions; at baseline and the month 7 visits. The monitor will be worn on a non-school day. If the child will not be attending school for the subsequent 24 hour period, then prior to leaving the clinic, the blood pressure monitor and cuff will be placed and worn for the 24 hour period. Clear instructions will be given to the child and his / her parents. If the child will be attending school within the subsequent 24 hours, the coordinator will demonstrate proper arm placement of the cuff, review the diary instructions and Ambulatory Blood Pressure Journal (AMBP) with the family for placement on the evening of a non-school day. Parents and participants will be instructed to avoid contact sports and swimming during the day of the recording and to keep a diary that reflects their daily activities and sleep time over the 24 hour period. A return prepaid mail box will be provided to each family. Parents will sign an agreement to return the monitor as soon as the study is completed.

The parent/legal guardian/family will be instructed to begin the home BP monitoring prior to bedtime on a non school day for a 24 hour period. For example, Saturday night bedtime is 9:30 PM, and then the cuff will be applied at that time and worn until 9:30 pm on Sunday evening. If the child will be attending school within the subsequent 24 hours, the family will be instructed to begin the home BP monitoring at 12:00 (noon) on the first non-school day following the clinic visit. Teaching will be done with the family on placement and proper use of the AMBP cuff and BP monitor system and an initial blood pressure reading will be taken in the clinic before discharge. The purpose will be to demonstrate to the family the proper use of the BP monitor and also to verify that the equipment is functioning properly before it is sent home with the parent/legal guardian.

The following parameters will be compared between groups:

1. Mean diurnal systolic, diastolic and mean BP
2. Mean nocturnal systolic, diastolic and mean BP
3. Mean 24 hour BP
4. BP dipping defined as the difference between mean awake and sleep systolic, diastolic and mean BP expressed as a percentage of awake measurement.
5. Blood pressure variability measured as BP SD / variance
6. Mean heart rate and heart rate variability AMBP MOP