24-hour blood pressure measurements: methodological and clinical problems

Ambulatory blood pressure monitoring in paediatric patients treated by regular haemodialysis and peritoneal dialysis

Ambulatory blood pressure monitoring (ABPM) has been shown to be more representative of blood pressure (BP) levels than casual BP measurements in adult patients treated by haemodialysis (HD). In this study we compared ABPM using the oscillometric SpaceLabs 90207 monitor with casual BP measurements in 35 paediatric patients [17 treated by peritoneal dialysis (PD) and 18 by HD]. Heart rate and plasma concentrations of atrial natriuretic peptide were also measured. No correlations were found between ABPM and causal BP measurements, except for systolic day-time BP in PD patients (r = 0.63). Seventy percent of PD and 33% of HD patients were regarded as hypertensive when evaluated by ABPM, while casual BP measurements demonstrated hypertension in 47% (P < 0.05) of PD patients and in 44% (NS) of HD patients. One-third of patients were reclassified by ABPM either from normotensive to hypertensive (7/19) or from hypertensive to normotensive (5/16). BP assessed by ABPM was higher in PD than in HD patients. The physiological decline of BP at night was significant and more pronounced in PD than in HD patients. In HD patients day-time BP did not differ between the 1st and the 2nd interdialytic day, but increased in the night hours before the following dialysis session. A positive correlation was found between day-time BP and pre-dialysis plasma atrial natriuretic peptide in both treatment groups. In conclusion this study demonstrates that casual BP recordings are not representative of average BP in dialysed paediatric patients. ABPM is useful in the diagnosis and treatment of hypertension in children with end-stage renal disease.

Experience with 24-hour ambulatory blood pressure monitoring in hypertension

Traditional sphygmomanometric blood pressure measurements may lead to errors in the diagnosis of arterial hypertension due to a number of factors, among which are the alerting reaction and pressor response induced in patients by the doctor's visit. This phenomenon, as quantified in our laboratory by continuous intraarterial recordings, is responsible for an average rise in systolic and diastolic blood pressure of 27/15 mm Hg, a rise that does not seem to be reduced by simply desensitizing the patient by means of more frequent physician visits. Twenty-four hour ambulatory blood pressure monitoring may theoretically improve the diagnostic approach to hypertensive patients by overcoming some limitations of isolated cuff measurements. In recording intraarterial blood pressure in 108 ambulant hypertensive subjects, we have found that 24-hour blood pressure values are able to discriminate among patients with different degrees of target organ damage better than isolated sphygmomanometric readings. Moreover, these studies have indicated that 24-hour blood pressure variability may be as important as blood pressure mean values in the assessment of cardiovascular complications. In clinical practice, however, intraarterial blood pressure monitoring is not feasible, and only noninvasive recorders can be used. Use of these devices does not induce any alerting reaction in the patients and does not interfere with day-night blood pressure changes. Although it is characterized by intermittent readings, this approach is not incompatible with a precise estimate of 24-hour blood pressure mean values.(ABSTRACT TRUNCATED AT 250 WORDS)