What is the role of ambulatory BP monitoring in pediatric nephrology?

Ambulatory blood pressure monitoring (ABPM) has been developed to overcome recognized deficiencies and inaccuracies of classic (office) BP measurements in the diagnosis and management of hypertension (HTN). Although in adults it has become a valuable tool for the diagnosis and ongoing management of HTN, and its use has been documented in over 50 studies in children, few pediatric nephrologists systematically use this approach for HTN assessment. Some of the reluctance to completely embrace the technique comes from the fact that none of the major hypertension trials has been based on ambulatory BP readings. The prognostic information from ABPM studies is slowly accumulating, but there is still relatively little information on the long-term prognostic value of ABPM-derived readings. For children there are particular problems in measuring representative BP values. It would be very helpful to know to what extent ABPM can help. However, there have been few comprehensive reviews in this particular population, which leaves the practicing nephrologist rather confused. The purpose of this review is to assess the present state of knowledge of ABPM usage in children, high-lighting important studies that help to delineate the place of ABPM in their medical management. We discuss: advantages and limitations of ABPM, the variability of blood pressure in children, clinical uses of ABPM in pre-dialysis renal failure, dialysis, renal transplantation, primary renal diseases, and diabetes, comparison with adult data. The relationship between casual BP (CBP) and ABPM is presented, specifically the prevalence and relevance of either white-coat hypertension or relative 'office' hypertension. We conclude that in 2004, the sole reliance on casual BP to diagnose and to treat hypertension in children brings with it many difficulties. ABPM offers some clear solutions to these problems and thus should be routinely used in appropriately defined clinical settings, but is not a panacea.