Edward J. Ruley

Feeding disorders and gastroesophageal reflux in infants with chronic renal failure

Twenty-two infants (mean age 7.5 months) with chronic renal failure (CRF) were studied for their nutrition, growth, and upper gastrointestinal function. Most infants had a history of poor caloric intake and 7 had received supplemental feeding (SF) prior to the investigation. All infants were undergrown, underweight, and malnourished. The infants were characterized as having only a fair interest in food, refusing feedings, and vomiting excessively. Sixteen of 22 infants (73%) had significant gastroesophageal (GE) reflux demonstrated by 24-h esophageal pH monitoring. Gastroesophageal scintiscans were less sensitive and specific in detecting the reflux. Infants with GE reflux were significantly younger and more often required SF than those without GE reflux. There were no significant differences in the degree of renal failure, growth failure, caloric intake, protein intake, or nutritional status between the infants with and without GE reflux. From these studies we conclude that GE reflux should be considered as one of the factors contributing to the feeding problems of infants with CRF.

Recombinant erythropoietin (Epogen) improves cardiac exercise performance in children with end-stage renal disease

To determine the effects of anemia in children with end-stage renal disease, we studied cardiac performance before and 1 and 6 months after recombinant erythropoietin (Epogen). Children with end-stage renal disease were included if they had significant anemia [hematocrit (Hct)<30%]. Epogen 50 U/kg was given subcutaneously or intravenously three times per week until the Hct was ≥33%. Echocardiography, cardiac output (acetylene rebreathing), and treadmill (modified Bruce) tests were performed. Boys (9) and girls (9), 11.9±5.6 years, were given Epogen and the Hct increased (from 21.7±2.7% to 33.4±2.1%,P=0.001). Heart rate decreased (P=0.04) and stroke volume did not change. Blood pressure did not change. Cardiac thickness, chamber dimensions, left ventricular wall stress, velocity of circumferential fiber shortening, and indices of diastolic function were normal and did not change after Epogen. Exercise time increased (from 10.3±1.9 to 11.2±1.9 min,P=0.01) after 1 month of Epogen. Resting oxygen consumption (VO2) decreased (from 7.8±1.8 to 6.9±1.4 ml/min per kg,P=0.01) 1 month after Epogen and peak exercise VO2 did not change after Epogen. There were no differences in exercise tests between the 1 and 6 month measurements. Exercise tolerance improves after the short-term correction of anemia and there is no further improvement after long-term correction.

Factitious hematuria: Diagnosis by minor blood group typing

fetal deformation has been said to be a frequent cause. In this series 29% of infants had a prenatal history associated with intrauterine constraint, and an additional 41% had some prenatal factors which might have induced constraint. Intrinsic malformations within the sternomastoid muscle might also produce wryneck or potentiate later deformation. Six infants in the study had rare, large cavernous hemangiomas about the head. It is possible that these children have a syndrome involving vascular malformations of the skin and neck muscles. The abnormal vessels within the sternomastoid might be more susceptible to rupture, either spontaneously or after constraint. Four of the infants had no history to suggest deformation, but one was a breech twin and another had associated deformations at the ankles. Careful evaluation of neck movement would seem warranted in any child with a cavernous hemangioma, especially above the neck. Another malformation mechanism for wryneck may not involve damage to the sternomastoid at all. One infant had apparent right congenital muscular torticollis and ipsilateral shortening of the limbs. This may represent an example of right-sided hemiatrophy or left-sided hemihypertrophy which included the neck muscle. Further examples of both these malformational etiologies for torticollis will be needed to establish them as discrete entities. Regardless of etiology, diligent early therapy should be instituted for any infant with torticollis. Passive stretching exercises have been a recommended treatment, :~ and we found that most infants struggled against these neck manipulations but complied well with the active stretching program. We hope that early treatment of torticollis can prevent much calvarial distortion, and that helmet therapy becomes generally available for infants with a persistent severe asymmetry.

Vancomycin Prevents Polytetrafluoroethylene Graft Infections in Pediatric Patients Receiving Chronic Hemodialysis

Polytetrafluoroethylene (PTFE) grafts have been a useful addition to the pediatric hemodialysis vascular access armamentarium. In this study, 17 pediatric patients underwent 331 total months of hemodialysis via PTFE grafts. There was a statistically significant (P less than .025) decrease in the incidence of graft infections in 12 patients (235 patient-months) while receiving prophylactic parenteral vancomycin compared with 9 patients (96 patient-months) while receiving no vancomycin (0% v 44%). Vancomycin side effects were uncommon and mild. Vancomycin is a safe and effective agent for the prevention of PTFE graft infections in pediatric patients receiving chronic hemodialysis.

Reconstruction of the renal artery after unsuccessful percutaneous transluminal angioplasty in children.

The use of percutaneous transluminal angioplasty as the primary treatment of renovascular stenosis in adults has recently been described. Previously, only three children have been reported to have undergone transluminal angioplasty for stenosis of the renal artery and hypertension. At our hospital, transluminal angioplasty was attempted in four children with renal artery stenosis; one attempt was successful and three were unsuccessful. The three patients who required surgical repair of the renal artery after unsuccessful transluminal angioplasty have been described in detail. The histopathology of the stenotic vessels is also discussed. Based on the analysis of the three children, certain criteria have been derived to select pediatric patients with renovascular hypertension either for attempted transluminal angioplasty or for primary surgical revascularization.

Efficacy of Once- versus Thrice-Weekly Subcutaneous Recombinant Human Erythropoietin in Children Receiving Continuous Cycling Peritoneal Dialysis

The subcutaneous administration of recombinant human erythropoietin is effective in the treatment of anemia of end-stage renal disease. Single-dose pharmacokinetic studies suggest the possibility of less frequent dosing via the subcutaneous route. In this study, dosing once-weekly was as effective as thrice-weekly subcutaneous dosing in maintaining the corrected hematocrit in a group of children receiving continuous cycling peritoneal dialysis. This regimen was preferred by and beneficial to both patients and their parents.

Use of low-dose subcutaneous recombinant human erythropoietin in end-stage renal disease: experience with children receiving continuous cycling peritoneal dialysis.

The use of recombinant human erythropoietin (rhEPO) for the treatment of renal anemia is well accepted. However, the lowest effective dose for subcutaneous (SC) administration has not been determined. This study documents that a dose of 50 U/kg administered three times a week was effective in 10 children (age range, 13 days to 18.6 years) receiving continuous cycling peritoneal dialysis (CCPD) for a period ranging from 0.25 to 23.5 months. Their hematocrit (hct) increased at an average rate of 0.26% points per day from a baseline of 19.8% +/- 3.1% to a value of at least 30% after a mean of 7.4 +/- 2.5 weeks of treatment. When compared with other studies, this response was more rapid than what has been observed with the same dose administered intravenously (IV). This response was similar to that seen with larger IV doses. Hypertension and functional iron deficiency were the most common complications. Two patients with previously controlled hypertension developed elevation in blood pressure that was easily controlled by oral antihypertensives. Six patients required IV iron dextran to reestablish treatment response. A SC rhEPO dose less than 50 U/kg three times a week may be effective in children and should be investigated.

Accelerated recovery from immune-mediated thrombocytopenia with plasmapheresis

Autoimmune thrombocytopenia unresponsive to corticosteroid therapy developed in a 16-year-old female with long-standing Sjögrens syndrome. Serial plasma exchange caused a linear decrease in platelet antibody titer associated with a concomitant rise in platelet count. Statistical analysis of sequential platelet counts revealed an increase with plasmapheresis and immunosuppression that was significantly greater than that achieved with immunosuppression alone (p less than 0.005).

Descriptions of the participating centers and patient population in the Growth Failure in Children with Renal Diseases Study.

The Growth Failure in Children With Renal Diseases Study, a double-blind, multicenter clinical trial with 108 children entered into the control period over 4.3 years of patient enrollment (December 1984 to April 1989), is being extended for 3 years (December 1988 to December 1991) to provide the time needed to accrue additional patients, aged between 1 1/2 and 10 years, with glomerular filtration rates of 20 to 75 ml/min/1.73 m2. The study design of randomization to two treatment arms (1,25-dihydroxyvitamin D vs dihydrotachysterol) requires a total of 108 patients with a minimum of 6 months of treatment to test the long-term effectiveness and safety of 1,25-dihydroxyvitamin D, an essential part of the therapeutic regimen for children with chronic renal insufficiency. The frequent longitudinal assessments of nutrition and growth in children with chronic renal insufficiency can better define the natural history of renal disease and its influence on growth. Similar data in the treatment period will define the impact of treatment with 1,25-dihydroxyvitamin D3 versus dihydrotachysterol on this natural history. Linear growth must be observed long enough (6 to 12 months minimum) to permit valid quantitation and comparison of the two vitamin D treatment arms, the multiple confounding variables that affect growth (e.g., steroid therapy, diabetes mellitus, prior vitamin D treatment) must be rigorously excluded or controlled, and the assignment of patients to the two groups must be random. These controls--sufficient study duration, sufficient patient numbers, and randomization--should eliminate extraneous sources of variation, including seasonal periodicity. This carefully developed, double-blind clinical trial with multiple participating centers and an effective organizational structure is coming close to achieving the goals of the study. An explosion of data regarding the natural history of chronic renal insufficiency and its treatment with vitamin D metabolites will be forthcoming at the conclusion of the study.

Fibrin configuration on glass led to decrease of neutrophil adherence in systemic lupus erythematosus

Using a previously developed in vitro assay of glass adherence of neutrophils following blood clotting, we compared the results of new patients with systemic lupus erythematosus (SLE), juvenile rheumatoid arthritis (JRA) and those of normal controls. In acute phase of the disease, all 33 patients (100%) of SLE, 2 of 35 patients (5.7%) with JRA had a significantly low neutrophil adherence to glass surface (less than 25% of the normal values). During 2 years follow-up in 18 patients with SLE from the onset of the disease, we consistently observed the low cell adherence during the relapses of the disease in all the patients. When remains of glass surfaces were examined under scanning electron microscope (SEM), we found a notable morphologic difference of fibrin configuration between the specimens of active SLE and normal controls. We conclude that the varied results of neutrophil adherence on glass may reflect the forming of different fibrin configuration induced by the in vitro contact system of coagulation. The findings may explain the increased thrombotic complications reported in patients with active SLE.