Haemofiltration in newborns treated with extracorporeal membrane oxygenation: a case-comparison study.

INTRODUCTION: Extracorporeal membrane oxygenation is a supportive cardiopulmonary bypass technique for patients with acute reversible cardiovascular or respiratory failure. Favourable effects of haemofiltration during cardiopulmonary bypass instigated the use of this technique in infants on extracorporeal membrane oxygenation. The current study aimed at comparing clinical outcomes of newborns on extracorporeal membrane oxygenation with and without continuous haemofiltration. METHODS: Demographic data of newborns treated with haemofiltration during extracorporeal membrane oxygenation were compared with those of patients treated without haemofiltration in a retrospective 1:3 case-comparison study. Primary outcome parameters were time on extracorporeal membrane oxygenation, time until extubation after decannulation, mortality and potential cost reduction. Secondary outcome parameters were total and mean fluid balance, urine output in mL/kg/day, dose of vasopressors, blood products and fluid bolus infusions, serum creatinin, urea and albumin levels. RESULTS: Fifteen patients with haemofiltration (HF group) were compared with 46 patients without haemofiltration (control group). Time on extracorporeal membrane oxygenation was significantly shorter in the HF group: 98 hours (interquartile range (IQR) = 48 to 187 hours) versus 126 hours (IQR = 24 to 403 hours) in the control group (P = 0.02). Time from decannulation until extubation was shorter as well: 2.5 days (IQR = 0 to 6.4 days) versus 4.8 days (IQR = 0 to 121.5 days; P = 0.04). The calculated cost reduction was euro5000 per extracorporeal membrane oxygenation run. There were no significant differences in mortality. Patients in the HF group needed fewer blood transfusions: 0.9 mL/kg/day (IQR = 0.2 to 2.7 mL/kg/day) versus 1.8 mL/kg/day (IQR = 0.8 to 2.9 mL/kg/day) in the control group (P< 0.001). Consequently the number of blood units used was significantly lower in the HF group (P< 0.001). There was no significant difference in inotropic support or other fluid resuscitation. CONCLUSIONS: Adding continuous haemofiltration to the extracorporeal membrane oxygenation circuit in newborns improves outcome by significantly reducing time on extracorporeal membrane oxygenation and on mechanical ventilation, because of better fluid management and a possible reduction of capillary leakage syndrome. Fewer blood transfusions are needed. All in all, overall costs per extracorporeal membrane oxygenation run will be lower.

Point-of-care creatinine testing in children at risk for sudden deterioration of renal function.

BACKGROUND: Point-of-care testing for creatinine blood concentrations may be useful in predicting the onset of recurrent conditions threatening renal function in children at home. Our aim was to evaluate two point-of-care systems for creatinine testing vs. an automated creatinine assay. METHODS: Twenty patients aged between 2 months and 17 years were randomly selected. Capillary blood specimens were taken for two point-of-care tests (Reflotron and i-STAT), and the results were compared to the routine enzymatic creatinine assay on a Hitachi 912 analyser using material collected simultaneously. RESULTS: The mean difference in creatinine concentration between the Reflotron and the Hitachi 912 and i-STAT and Hitachi 912 test was -16 and 4 micromol/L, respectively. The slope of the Passing-Bablok method comparison was 0.95 (95% CI 0.87-1.06) and 0.96 (95% CI 0.90-1.00) for the Reflotron and i-STAT test, respectively. CONCLUSIONS: The blood creatinine concentrations measured using the Reflotron and the i-STAT device correlated well with those from the routine assay, especially in the concentration range up to 500 micromol/L. Both systems are good options for point-of-care creatinine testing in capillary blood. However, the i-STAT seems the better option for monitoring at home given its greater ease of use.

Cardiovascular disease as a late complication of end-stage renal disease in children.

As in older adults, cardiovascular disease is the most important cause of death in adolescents and young adult patients with end-stage renal disease (ESRD) since childhood. This concerns patients on dialysis as well as transplant patients, despite the fact that a long duration of dialysis during childhood is an extra mortality risk factor. Left ventricular hypertrophy (LVH), aortic valve calcification, and increased arterial stiffness, but not increased arterial intima media thickening, are the most frequently observed alterations in young adult survivors with childhood ESRD. In transplanted patients a concentric LVH as a result of chronic hypertension is mostly observed; in dialysis patients a more asymmetric septal LVH is found as a result of chronic volume overload. These results suggest that in children and young adults with ESRD chronic pressure and volume overload, a high calcium-phosphate product, and chronic inflammation, but not dyslipidemia, play a role in the development of cardiovascular disease.

Severe bone disease and low bone mineral density after juvenile renal failure.

BACKGROUND: Little is known about the late effects of juvenile end-stage renal disease (ESRD) on bone integrity. To establish clinical manifestations of metabolic bone disease and bone mineral density (BMD) in young adult patients with juvenile ESRD, we performed a long-term outcome study. METHODS: A cohort was formed of all Dutch patients with onset of ESRD between 1972 and 1992 at age 0 to 14 years, born before 1979. Data were collected by review of medical charts, current history, physical examination, and performing dual energy x-ray absorptiometry (DEXA) of the lumbar spine and the femoral neck. RESULTS: Clinical information was retrieved in 247 out of 249 patients. Of all of these patients, 61.4% had severe growth retardation (<-2 SD), 36.8% had clinical symptoms of bone disease, and 17.8% were disabled by bone disease. Growth retardation and clinical bone disease were associated with a long duration of dialysis. DEXA was performed in 140 out of 187 living patients. Mean BMD +/- SD corrected for gender and age (Z score) of the lumbar spine was -2.12 +/- 1.4 and of the femoral neck was -1.77 +/- 1.4. A low lean body mass was associated with a low lumbar spine and a low femoral neck BMD; male gender, physical inactivity and aseptic bone necrosis were associated with a low lumbar spine BMD. CONCLUSION: Bone disease is a major clinical problem in young adults with pediatric ESRD. Further follow-up is needed to establish the impact of the low bone mineral densities found in these patients.

Increased arterial stiffness in young adults with end-stage renal disease since childhood.

Increased arterial stiffness is a risk factor for mortality in adults over 40 yr of age with end-stage renal disease (ESRD). As no data exist on vascular changes in young adults with ESRD since childhood, a long-term outcome study was performed. All living Dutch adult patients with onset of ESRD between 1972 and 1992 at age 0 to 14 yr were invited for carotid artery and cardiac ultrasound and BP measurements. Data on clinical characteristics were collected by review of all medical charts. Carotid ultrasound data were compared with those of 48 age-matched and gender-matched healthy controls. Carotid artery and cardiac ultrasound was performed in 130 out of 187 eligible patients. Mean age was 29.0 (20.7 to 40.6) yr. Compared with controls, patients had a similar intima media thickness but a reduced mean arterial wall distensibility DC (40.0 versus 45.0 kPa(-1). 10(-3); 95% CI, -9.1 to -0.8; P < 0.001), an increased stiffness parameter beta (4.2 versus 3.8; 95% CI, 0.05 to 0.68; P = 0.02), an increased elastic incremental modulus E(inc) (0.35 versus 0.27 kPa. 10(3); 95% CI, 0.02 to 0.12; P < 0.001). Multiple regression analyses in all subjects revealed that ESRD was associated with an increase in beta and E(inc). Arterial wall properties of patients currently on dialysis and transplanted patients were comparable. In all patients, current systolic hypertension was associated with increased E(inc) and decreased DC. In conclusion, carotid arterial wall stiffness is increased in young adult patients with pediatric ESRD. Hypertension is a main determinant and might be a target for treatment of these potentially lethal arterial wall changes.

Mortality and causes of death of end-stage renal disease in children: a Dutch cohort study.

BACKGROUND: To establish mortality rates, causes of death, and determinants of mortality in children with end-stage renal disease (ESRD), we performed a national long-term follow up study. METHODS: Mortality rate was determined in all Dutch patients with onset of ESRD at ages 0 to 14 years in the period between 1972 and 1992. Causes of death and mortality determinants were investigated in all patients of this cohort who were born before 1979. Data were derived from the Dutch Registry for patients on renal replacement therapy (RRT), medical charts and National Health Database. RESULTS: Of all 381 patients 85 had died. The overall mortality rate (MR) was 1.57/100 patient-years, and the standardized mortality rate (SMR) was 31.0. The MR for patients 0 to 5 and 6 to 10 years old at onset of ESRD decreased from, respectively, 7.0 (range 0-14.9) to 3.9 (1.2-6.7) and 4.3 (1.1-7.5) to 1.6 (0.3-2.8) between the periods 1972-1981 and 1982-1992. The mortality hazard ratio of relatively long standing dialysis and of long standing hypertension were, respectively, 7.2 (4.4-11.8) and 3.1 (2.1-4.6), of cyclosporine-introduction in transplanted patients 0.3 (0.1-0.4). Overall cerebrovascular accidents (24%) and infections (21%) were the most common causes of death; after 10 years of RRT cardiac death (7/21) was most prevalent. Cardiovascular death was most prominent in dialysis as well as transplanted patients. CONCLUSION: Survival in children with ESRD has increased over the last 20 years, but the SMR remains high. Early transplantation and a more vigorous approach toward hypertension and infection may be mandatory in order to further reduce mortality.

Property modification factors for seismic isolation bearings

The overall objective of this task was to develop an improved understanding of the expected performance and behavior of sliding isolationsystems;evaluate their functionality, reliability, and longevity; and assist in the development of improved codes and specifications for their use. This report deals with the problem of establishing upper and lower bound values of properties of seismic isolation bearing for use in the analysis and design of seismicallyisolated bridges. These bounding values of properties are determined by using system property modification factors. The concepts and the values presented represent the basis on which bounding analysis is described in the new 1999 "AASHTO Guide Specifications for Seismic Isolation Design"