[Vascular accesses for chronic hemodialysis in children]. / Accesos vasculares para hemodiálisis crónica en niños.

BACKGROUND: The success of a chronic hemodialysis program depends on a good vascular access. AIM: To evaluate the experience with vascular accesses for chronic hemodialysis in pediatric patients. PATIENTS AND METHODS: One hundred fifty-one vascular accesses used in 60 pediatric patients (33 female) coming from 2 hemodialysis (HD) centers were analyzed. RESULTS: The average age of admission to the hemodialysis program was 10 years old (range 1.8-15). Forty percent of accesses were internal arterio-venous fistulae (AVF), 58% were central venous catheters and 2% were grafts. Twenty four patients required a central venous catheter from the beginning since they required immediate dialysis. Twenty patients began dialysis with a permeable AVF and never required another vascular access. Eight small children used a central catheter as the only vascular access and 32 patients required both types of vascular accesses. Eighty-seven catheters were used in 34 patients, of which 77 were temporary and 10 permanent. Seventeen patients needed only one catheter and one girl required 15 catheters. The average life span for AVF was 524 days (20-1277), for temporary catheters 34 days (1-76) and for permanent catheters 73 days (9-147). Two years survival of AVF was 95%. One month survival for subclavian and jugular catheters was 50%. Fifty-six percent of AVF had no complications, 12 failed due to insufficient flow and 24% had a complication. Of the 87 catheters placed, 75% had complications and 22 were electively removed. CONCLUSIONS: Arteriovenous fistula is the vascular access of choice for hemodialysis in pediatric patients. Central venous catheters can become an essential access, specially in small children.

[Chronic hemodialysis in children]. / Hemodiálisis crónica en pediatría.

BACKGROUND: The final objective of every children that is admitted to a program o hemodialysis of peritoneodialysis is to receive a renal graft. AIM: To report the experience in pediatric hemodialysis in two pediatric hospitals in Chile that are reference centers for renal transplantation. PATIENTS AND METHODS: Sixty patients, 55% female, aged 2 to 15 years old, admitted to the dialysis and transplant program since 1987, with a creatinine clearance of less than 20 ml/min/1.73 m2, were studied. RESULTS: Twenty percent of children were less than 5 years old at the moment of admittance to the program and 3.3% weighed less that 10 kg. Etiologies of end stage renal disease were glomerulopathies in 33.4%, reflux nephropathy in 27.7%, obstructive uropathy in 13.3%, hypoplasia/dysplasia in 10%, hereditary problems in 8.3% and vascular disorders in 5%. Eighty six percent of patients were dialyzed less than 2 years and 5% more than 4 years. Fifty percent had received prior medical treatment, 5% had been treated with intermittent peritoneal dialysis, 5% with chronic ambulatory peritoneal dialysis and 20% presented as a terminal renal failure. Sixty two percent received a renal graft, 25% is still on hemodialysis, 3.3% switched to chronic ambulatory peritoneal dialysis, 3.3% had a recovery of renal function and 6.7% died being on hemodialysis. Arterio-venous fistulae were the vascular accesses in 75% of patients, double lumen catheters in 50% and vein grafts in 5%. Malfunctioning or infections were the main complications of arterio-venous fistulae, accounting for 30% of hospital admissions. CONCLUSIONS: The availability of new vascular accesses and new hemodialysis machines specially designed for children, along with specially trained health care personnel, should reduce the mortality and complication rates of hemodialysis in this age group.

[Interstitial nephritis syndrome and uveitis]. / Síndrome nefritis intersticial aguda y uveítis.

A nine year old male patient was admitted to a metropolitan general hospital at Santiago, Chile, because of unexplained severe anemia (hematocrit 18%) and redness of the right eye. Uveitis was confirmed by ophthalmological examination. Laboratory work up showed an erythrocyte sedimentation rate of 101 mm.h, marked nitrogen retention (BUN 91 mg/dl), creatinine clearance was 9 ml/min.1,73 sq m, serum IgG and IgM immune globulin concentrations were 2,368 mg/dl and 263 mg/dl respectively, over the normal range for age, with almost absent serum IgA and reduced T cell populations. Negative rheumatoid factor, antinuclear antibodies and anti smooth muscle antibodies reactions were obtained, together with normal levels of C3 and C4 fractions of complement and normal urine sediment. Renal biopsy specimen included 25 glomerular, one of them was wholly sclerotic, another two had periglomerular fibrosis and the remainder showed only slightly increased mesangial matrix. Heavy mononuclear inflammatory interstitial infiltration, with granulomatous structures including giant multinuclear cells as those seen in foreign body reactions (fig 1) and PAS positive intraluminal tubular crystals were also observed. In spite of steroidal treatment, which was complicated by an inflammatory brain granuloma that healed in coincidence with parenteral antibiotic therapy, the patient evolved toward chronic renal failure. We think that the available evidence strongly suggests an immunological disorder as a very likely explanation for this case.