Ambulatory blood pressure monitoring in children with aortic coarctation and kidney transplantation.

BACKGROUND: Ambulatory blood pressure monitoring (ABPM) has been found to be of significant importance in clinical practice because numerous blood pressure (BP) measurements may be made throughout the 24-hour period. OBJECTIVE: To assess the clinical utility of ABPM in children with secondary hypertension. METHODS: We studied 37 patients (21 boys and 16 girls), with a mean age of 16.4 +/- 4.1 years, after kidney transplantation and 38 patients (27 boys and 11 girls), with a mean age of 10.2 +/- 2.1 years, after surgical correction of aortic coarctation. Data, expressed as mean +/- SD, were analyzed after dividing the patients into 4 groups. Group A consisted of 25 patients receiving antihypertensive therapy; group B included 12 patients not receiving antihypertensive therapy. Group C included 25 patients operated on before 3 years of age (8 +/- 7 months of age); group D included 13 patients operated on after 3 years of age (74 +/- 29 months of age). RESULTS: In groups A and B, casual BP measurement showed that 16 of 37 patients (43%) were hypertensive; 24-hour ABPM detected a larger number of patients who were hypertensive (23 of 37, 62%); there were 18 in group A and 5 in group B. In groups C and D, casual BP measurement identified 6 of 38 (15%) patients as hypertensive, whereas 24-hour ABPM again identified a higher number (13 of 38, 34%). CONCLUSIONS: Our findings confirm that 24-hour ABPM is more sensitive than casual BP in detecting abnormal BP in patients at high risk for secondary hypertension.

Left ventricular hypertrophy, treadmill tests, and 24-hour blood pressure in pediatric transplant patients.

BACKGROUND: Hypertension and left ventricular hypertrophy (LVH) are possible complications in pediatric patients after renal transplantation. METHODS: We performed left ventricular echocardiography, 24-hour ambulatory blood pressure monitoring (24-hr ABPM), and treadmill tests in 28 pediatric renal transplant patients (mean age 16.1 +/- 3.7; time since transplantation 36 +/- 23 months). Left ventricular mass (LVM) was indexed for height 2.7. RESULTS: LVH was found in 82% of the patients. Seven of these patients were normotensive by 24-hour ABPM, but five patients showed a hypertensive systolic BP response during the treadmill test. LVM/height 2.7 correlated significantly with the mean 24-hour systolic BP (P = 0.002) and with the maximal exercise systolic BP (P = 0.002). CONCLUSION: LVH is frequent in pediatric renal transplant patients. More information is needed with respect to the risk for LVH, including data from 24-hour ABPM and treadmill testing.

Exercise tolerance and blood pressure response to exercise testing in children and adolescents after renal transplantation.

The aim of the study was to assess exercise tolerance and blood pressure (BP) response to treadmill exercise in children after renal transplantation. Forty-five children were selected (29 males and 16 females) whose mean age was 14.3 +/- 4.2 years. All children had Hb >/= 10 g/dl and creatinine clearance >/=40 ml/min/1.73 m2. They were at least 6 months posttransplantation and were on triple immunosuppressive therapy. Twenty-seven were also on various antihypertensive medications. Each underwent clinical examination and measurement of BP, both at rest and during exercise testing on treadmill. The test was stopped on muscular fatigue or exhaustion. The patients were divided into two groups: those off (A) or on (B) antihypertensive therapy. When compared to a population of healthy children the patients had reduced exercise tolerance (10.1 +/- 2.1 vs 15.1 +/- 1.7 min, p < 0.001) (67 +/- 16%), increased heart rate (174 +/- 19 vs 161 +/- 19 beats/min, p < 0.001) (109 +/- 15%), and increased maximum systolic BP (150 +/- 26 vs 134 +/- 13 mmHg, p < 0. 001) (113 +/- 19%) at comparable workloads. Within the two patient groups, significant differences were observed during exercise testing for maximum heart rate, which was lower in group B (p = 0.03), and maximum systolic BP, which was higher in group A (p = 0.04). Our study confirms that children and adolescents on immunosuppressive therapy after renal transplantation have a hypertensive response during exercise, probably related to medication-induced peripheral vascular tone.

Hypertension in young patients after renal transplantation: ambulatory blood pressure monitoring versus casual blood pressure.

The results of ambulatory blood pressure monitoring (ABPM) in children after kidney transplant were analyzed to ascertain any alteration in circadian BP profile, degree of hypertension, and efficacy of therapy. The data were also compared with casual BP data and left ventricular mass index (LVMI). We have examined 30 patients (17 male, 13 female), mean age 16.1+/-3.6 years after kidney transplant. All patients were receiving triple immune-suppressive therapy and 20 of them were also taking antihypertensive therapy. They underwent clinical examination with measurement of BP at rest, echocardiogram mono-2D, and ABPM. The following ABPM parameters were recorded: systolic (S) and diastolic (D) BP at rest; mean 24-h SBP and DBP; mean daytime SBP and DBP; mean nighttime SBP and DBP; nocturnal fall in SBP and DBP; and mean daytime and nighttime heart rate (HR). The patients were divided in two groups. Group A consisted of 20 patients taking antihypertensive treatment; group B consisted of 10 patients not taking antihypertensive treatment. Casual and ABPM data for the two groups were compared using the Student t test for unpaired data. Blood pressure at rest and LVMI were not statistically different between the two patient groups. The ABPM data showed statistical differences between the two groups for mean 24-h SBP and DBP, daytime and nighttime SBP, nighttime DBP, fall in nocturnal DBP, and nighttime HR. Mean 24-h SBP and DBP, mean daytime SBP and DBP, and mean nighttime SBP and DBP were significantly correlated to LVMI (respectively, P = .009, P = .005, P = .008, P = .007, P = .05, and P = .01). Twenty-four-hour ABPM was more useful in the diagnosis and management of hypertension than was casual BP at rest.

Combined heart and kidney transplantation in a child: will we need it more in the future?

A 12-year-old girl affected by idiopathic dilated cardiomyopathy and renal failure was referred to our institution for cardiac transplantation. A simultaneous heart-kidney transplantation from the same donor was decided. The immunosuppression schedule consisted of azathioprine, antithymocyte globulin, steroids, and cyclosporine. At a follow-up visit at 24 months after transplantation, no episodes of heart or kidney rejection had occurred and cardiac and renal function were good. Concomitant failure of heart and kidney is well known in the literature, but it appears to be more frequent in adult as compared with the pediatric population. This is the first case of combined heart and kidney transplantation in a child. Because of the successful outcome and good follow-up, the number of combined organ transplantations will most likely increase in the future.

Exercise tolerance and behavior of blood pressure in children and adolescents after renal transplant.

OBJECTIVE: The purpose of the study was to evaluate the exercise tolerance and the behaviour of blood pressure during a maximal exercise testing on treadmill for a group of patients with renal transplant carried out at least 6 months earlier. EXPERIMENTAL DESIGN, SETTING AND PATIENTS: In a retrospective study, nineteen patients were examined in our laboratory: 13 boys and 6 girls, mean age 15.8 years (range 10.5-22). INTERVENTIONS: All patients were given a clinical examination, an ECG at rest, a maximal exercise testing on treadmill (Bruce protocol), a mono-2D echo, a lung function test and 24-hour Holter monitoring. The results of the exercise test were compared with those of two control groups of same age and body surface area. RESULTS: The clinical examination of their cardiovascular apparatus gave normal results. The echo revealed anatomical and heart function anomalies related to the original disease. Exercise testing on treadmill showed a reduction in exercise tolerance (p < 0.001) and the maximal heart rate showed a statistically significant difference (p < 0.001) in comparison to control groups. Maximal systolic blood pressure was higher than in patients with same body surface area (p < 0.001) and higher than in peers (p = 0.133). CONCLUSIONS: In view of this hypertensive response, strenuous physical activity should be undertaken with caution and indeed submaximal aerobic activity is more suitable for this population of patients.

Abnormal hypertensive response during exercise test in normotensive transplanted children and adolescents.

We investigated the cardiovascular and respiratory conditions, at rest and in response to stress testing, in 10 children and adolescents with successful renal transplantation, to release certifications for participation in sports. Our patients were aged more than 6 years, transplanted 6 months or more before the study, with creatinine clearance > 40 ml/min/1.73 m2, without hypertension at rest. All but 1 were on cyclosporine A, prednisone and azathioprine. Two control study groups with the same chronological age and body surface area were paired with our patients. They underwent a graded exercise tread-mill test, during which maximal blood pressure and heart rate were recorded. Resting electrocardiogram, dynamic 24-hour electrocardiogram Holter monitoring and mono- and bidimensional echocardiograms were obtained before the test. Spirometry was performed to study lung flow and volume. A questionnaire collected information about physical activity patterns. Four categories, according to practice, frequency and duration of exercise, were identified: nonactive, starters, experienced and very experienced. Most children and adolescents were sedentary or mildly interested in sports and during treadmill test we observed reduced exercise capacity and systolic hypertensive response to increasing exercise testing.

Haemolytic-uraemic syndrome in childhood: surveillance and case-control studies in Italy. Italian HUS Study Group.

Seventy-six cases of haemolytic-uraemic syndrome (HUS) were collected over a 4-year period during a surveillance and case-control study. The annual incidence of 0.2 per 100,000 children aged 0-14 years is lower than in other countries; 34% had no prodromal diarrhoea. Evidence for verocytotoxin-producing Escherichia coli (VTEC) infection was found in 72% of patients and 3% of controls; 88% of patients with bloody diarrhoea, 67% with non-bloody diarrhoea and 55% without diarrhoea were VTEC positive. Seventy-three percent of patients had creatinine clearance > or = 80 ml/min per 1.73 m2, normal blood pressure, no proteinuria and haematuria < 2+ after 1 year of follow-up. One patient died and none had non-renal sequelae. VTEC positivity was significantly correlated with a good outcome, while the absence of diarrhoea and a high total white blood cell count at onset were not predictors of a bad outcome. Household contacts of HUS patients had diarrhoea more frequently than those of the control group, supporting the hypothesis of person-to-person transmission of VTEC infection.

Hemolytic-uremic syndrome and Vero cytotoxin-producing Escherichia coli infection in Italy. The HUS Italian Study Group.

In a 3-year prospective study, 49 Italian children with the hemolytic-uremic syndrome (HUS) were examined for evidence of infection with Vero cytotoxin-producing Escherichia coli (VTEC). Diagnosis of infection was established in 37 patients (75.5%) by the combined use of stool examination for VTEC and for free fecal neutralizable Vero cytotoxin and serum analysis for antibodies to the Vero toxins and the lipopolysaccharides (LPS) of three major VTEC serogroups (O157, O26, O111). Anti-LPS antibodies were detected in sera from 30 patients: 25 had antibody to O157 LPS, 4 to O26, and 1 to O111. In as many as 27 patients (55.1%), diagnosis of infection relied only on serologic findings, and the presence of antibody to LPS was the sole evidence of VTEC infection in 20 patients (40.8%). The use of LPS from different E. coli serogroups provided evidence that in Italy O157 strains are the most prevalent VTEC involved in HUS.

Isolation in Italy of a verotoxin-producing strain of Escherichia coli O157:H7 from a child with hemolytic-uraemic syndrome.

Verotoxin-producing Escherichia coli O157:H7 was isolated for the first time in Italy from a child with hemolytic-uremic syndrome and his asymptomatic sister. Both parents remained asymptomatic, and neither had evidence of this infection. The source of the infection was not identified, but the children had eaten ground beef during the 15 days prior to the onset of symptoms.

Evaluation of acid-base balance and pO2 with acetate dialysis in non-uremic patients.

The aim of our work was to evaluate the immediate effects of acetate-dialysis in patients with normal renal and respiratory function. For this purpose pH, pO2, pCO2 and HCO3- were monitored in arterial blood before dialysis, after 60, 120, 180 mns and at the end of each treatment in two groups of patients on chronic hemodialysis, a first group of schizophrenic patients and a second group of uremic patients. In the first group of patients the predialytic values were in the normal range. After hemodialysis HCO3- and pCO2 significantly decreased, both these changes were associated with a stable pH. The pO2 significantly decreased after 60 mns of dialysis. At the end of dialysis the pO2 increased without significant variation compared to predialytic values. In conclusion in non-uremic hemodialysis patients metabolic acidosis due to the loss of bicarbonate through the membrane is compensated by respiratory alkalosis. This respiratory alkalosis is not due to hypoventilation secondary to respiratory centre inhibition, but is mainly due to the pCO2 loss through the dialysis membranes.

25-hydroxycholecalciferol in the treatment of renal osteodystrophy in haemodialysed patients.

The effects of 25-OHD3 on renal osteodystrophy have been studied in 6 patients on maintenance haemodialysis. Administration of 25-OHD3, 50 microgram/day, did not improve biochemical data and intestinal absorption of calcium. With a dose of 100 microgram/day in all patients an increase in blood calcium levels eventually reaching hypercalcemic values was observed. In two cases a fall in alkaline phosphatase toward normal values was noted. In the same cases the treatment-induced hyperphosphatemia, uncontrolled by AI(OH)3 supplementation and similarly high iPTH levels were observed. In two cases repeated bone biopsy following 8 months treatment and not show substantial improvement of bone lesions. In one case addition of 1,25-(OH)2D3 to the treatment with 25-OHD3 led to a more rapid improvement in biochemical parameters and iPTH serum levels. Doses of 25-OHD3 capable to correct blood calcium levels and intestinal absorption of calcium, may have minimal benefit on the osteitis fibrosa component of the bone lesion.

[Behavior of serum 25-hydroxycholecalciferol in humans after administration of vitamin D and 25-OHD3]. / Comportamento del 25-idrossicolecalciferolo serico nell'uomo dopo somministrazione di vitamina D e 25-OHD3.

Serum levels of 25 hydroxycholecalciferol were evaluated following i.m. and p.o. vit. D2 and D3 and p.o. 25OHD3 administration. While no increment in 25OHD3 serum levels were observed after i. m. administration of non-hydroxylated calciferols, a marked increment of the metabolite was found following the oral administration. However the peak values were largely impredictable. Acute and chronic p.o. administration of 25OHD3 determines a rapid and dose-dependent increase of the serum levels of the metabolite. In addition considering that a lower dosage is required of 25OHD3 compared to vit. D, this metabolite is preferable in the therapeutic use.