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Biomedical subjects

D F Geary

Publications and source records attributed to D F Geary.

At least 19 recordsLinked to original sources
PubMed2001

Maintenance intravenous iron therapy in pediatric hemodialysis patients.

Iron supplementation is required for optimal response to erythropoietin (EPO) in hemodialysis patients. This is due to blood lost in the dialysis tubing after dialysis and the increased demand for iron by EPO therapy. Maintenance intravenous (IV) iron was administered according to a standardized protocol to pediatric patients on hemodialysis in our institution. The effect of this protocol on EPO dose, iron indices, anemia, and medication costs was evaluated. Data on two groups of patients were retrieved from the health records. Group 1 (n=14) consisted of patients treated in the 18 months prior to the protocol. These patients received oral iron supplements and occasional IV iron. Group 2 (n=5) consisted of all patients treated with the IV iron protocol. There was no difference in clinical characteristics and mean values for monthly hemoglobin, serum iron, ferritin, and transferrin saturation between groups. The dose of EPO was significantly reduced in group 2 compared with group 1 (193.9 +/- 121.4 vs. 73.9 +/- 39.0 units/kg per week, P<0.05). Medication costs were reduced by 26% in group 2. No significant adverse events were seen. Maintenance IV iron reduced the dose of EPO required to maintain blood hemoglobin levels. Our results also suggest that maintenance IV iron is a more-economic method of iron supplementation for pediatric hemodialysis patients.

Anemia↗
PubMed2000

Can the DOQI guidelines be met by peritoneal dialysis alone in pediatric patients? Dialysis Outcomes Quality Initiative.

DOQI guidelines recommend minimal standards for automated peritoneal dialysis (APD), with a weekly Kt/V of 2.1 and creatinine clearance (Ccr) of 63 l/1.73 m2. The purpose of this study was to assess if the DOQI guidelines could be met by dialysis alone in children on PD. Dialysis clearance studies were retrospectively analyzed in 20 pediatric patients on APD, all with a dwell volume of at least 1,000 ml/m2. Mean dialytic Kt/V was 2.0; only 45% had a Kt/V above the recommended 2.1. Mean dialytic Ccr was 43.5 l/week per 1.73 m2; only 10% achieved a Ccr above the recommended 63 l/week per 1.73 m2. Despite the significant correlation between total therapy volume (TTV) and both Kt/V and Ccr, only 2 of 10 patients with a TTV over 10 l/m2 per day reached the target Ccr. All patients had currently recommended dwell volumes, therapy times, and nocturnal cycles, but DOQI guidelines were difficult to achieve with dialysis alone. Strict adherence to DOQI guidelines in anephric pediatric PD patients may result in changing dialysis modality. However, without evidence of a correlation between delivered dose of dialysis and improved outcome, adequate dialysis should not be assessed by only measuring Kt/V and Ccr.

Canada↗
PubMed1999

Complications of gastrostomy feeding in children receiving peritoneal dialysis.

Gastrostomy tube (g-tube) feeding is recognized to improve the nutritional delivery to children with end-stage renal disease. A retrospective study was undertaken assessing the complications of g-tube feeding in children receiving peritoneal dialysis (PD). Twenty-three patients, mean age 3.8+/-3.2 years received PD and g-tube feeding for 758 patient-months, with 127 patients receiving PD for 1,969 patient-months used as controls. Peritonitis occurred every 18.4 patient-months in controls and 7.8 patient-months in those with a g-tube. Peritonitis occurred every 6.0 patient-months before and 8.1 patient-months after g-tube insertion in those undergoing g-tube insertion on PD. PD catheter exit site infection (PDESI) occurred every 18.7 patient-months in controls and 16.8 patient-months in those with a g-tube. PDESI occurred every 126 patient-months before and 16.2 patient-months following g-tube insertion. PD catheter replacement secondary to infection occurred every 109.4 patient-months in controls and 39.9 patient-months in those with a g-tube. It did not occur before g-tube insertion and occurred every 32.5 patient-months following insertion. Thirty-four episodes of g-tube exit site infection occurred, in 10 the same organism caused concurrent peritonitis. G-tube replacement occurred on 37 occasions. Hemodynamically significant gastrointestinal bleeding occurred in 3 patients, being terminal in 1. We conclude that, although not without risk, g-tube feeding in patients receiving PD is not contraindicated.

Bacterial Infections↗
PubMed1999

Hemodialysis for end-stage renal disease in children weighing less than 10 kg.

Hemodialysis (HD) of infants with end-stage renal disease (ESRD) is technically difficult and labor intensive, although there are few data in the literature to document the outcomes of this treatment. We retrospectively reviewed all patients with ESRD who received HD between 1983 and 1997 who weighed <10 kg at the beginning of HD. A total of ten patients aged 2-27 months, weighing 3.5-9.5 kg, were identified. All patients were dialyzed through a central venous line; three had a failed sapheno-femoral loop and one a failed brachial shunt. Line clot was observed in nine and line sepsis in six patients. Subclavian vein stenosis was documented in one patient following removal of a clotted subclavian line. The mean urea reduction ratios calculated during the 1st and 3rd month of HD were only 54% and 49%, respectively. Anemia was a frequent problem, despite the use of erythropoietin in seven of the infants. Outcomes included: successful renal transplant in four, switch back to peritoneal dialysis in two, improved renal function and dialysis discontinuation in one, and death after withdrawal of treatment in three patients. All three patients who died were <5 months of age, weighed <5 kg, and were anuric; two of the three had congenital nephrotic syndrome. In conclusion, successful HD is possible in small children with ESRD, but morbidity is substantial and mortality is high.

Age Factors↗
PubMed1998

Extrauterine twin-twin transfusion affects renal function and perioperative management of conjoined twins.

This series describes the occurrence of unbalanced circulatory shunting in three consecutively treated pairs of conjoined twins. The impact of renal functional changes and compensatory cardiac physiology on the timing of surgery and perioperative management are illustrated. The craniopagus set of twins presented in renal failure (1A) and cardiac failure (1B) to our hospital at age 2.5 years. Renal transplantation for anuria was performed in 1A before separation of the twins. This did not improve urine output in the hypoperfused twin, and normal renal function was not restored until the twins were separated. Two sets of omphalopagus twins were delivered and transferred to our hospital and separated during the first week of life. In each case a preoperative oliguric state in the underperfused twin reversed after separation, and a postoliguric diuresis ensued. Serum creatinine levels were similar in each pair preoperatively despite the inequality in urine volumes. In conjoined twins, assessment of renal function is necessary and should include serial measurements of urine volumes and urine creatinine clearance. Serum creatinine is not a useful marker of individual twin renal function in this situation. When disparity in renal function exists, early separation is indicated to prevent renal failure and compensatory cardiac failure.

Child, Preschool↗
PubMed1996

An economic evaluation of hospital-based hemodialysis and home-based peritoneal dialysis for pediatric patients.

The purpose of this study was to assess the relative health system cost of pediatric ambulatory hospital-based hemodialysis and home-based peritoneal dialysis, including both continuous ambulatory peritoneal dialysis and continuous cycling peritoneal dialysis when either treatment is equally appropriate. A cost analysis was performed from the viewpoint of the "study hospital" and service providers (physicians) using treatment protocols, based on current clinical practice, which incorporate procedures to establish dialysis access sites, ongoing dialysis maintenance, and possible complications. Cost estimates used information from the period between April 1, 1993, to March 31, 1994, including fully allocated inpatient and outpatient costs. A sensitivity analysis was conducted to analyze the effect of complications on treatment costs. Total annual costs (in 1994 Canadian dollars, $1.00 CDN approximately $0.75. US) of a typical and uncomplicated continuous ambulatory peritoneal dialysis, continuous cycling peritoneal dialysis, and hemodialysis patient were $47,569, $48,658, and $76,023, respectively. Differences in cost between peritoneal dialysis and hemodialysis patients were due to hemodialysis maintenance costs, which were attributed to larger physician fees (25.8 percent), greater direct treatment costs incurred by the study hospital (14.2 percent), and higher overhead costs (60.0 percent). The expected total cost of hemodialysis complicated by an arteriovenous fistula clot and central venous line blockages, or peritoneal dialysis complicated by hernia repair and peritonitis was $78,568 and $50,438 for hemodialysis and peritoneal dialysis, respectively. For the range of complication probabilities considered, expected total costs were always lower with peritoneal dialysis than with hemodialysis. The cost analysis demonstrates that peritoneal dialysis is less costly than hemodialysis for pediatric patients. Such analyses are but one component of the treatment decision, and as such, should not be viewed as the sole means to yield a treatment decision, but rather as a device for systematically evaluating the alternative treatment options.

Canada↗
PubMed1994

Renal biopsy in children: comparison of two techniques.

Two hundred and thirty-five children who underwent percutaneous renal biopsy under real-time ultrasound guidance at The Hospital for Sick Children, between 1 January 1991 and 31 March 1993, were studied to compare the incidence of complications after biopsies with the Trucut needle (TN) and the Bard Biopty gun (BG). Of the 190 cases for which full clinical details were available and in which a single instrument was used for renal biopsy, 157 were biopsied with the BG and 33 with the TN. There was no significant difference between the two groups in variables such as age, weight, sex, number of needle passes and number of tissue cores obtained. The proportion of native and allograft biopsies in each group was similar. More children in the TN group underwent biopsy under general anaesthesia. Adequate diagnostic tissue samples were obtained in 189 of 190 cases. There were more complications in the TN group than in the BG group (P < 0.001). When allograft and native kidney biopsies were analysed separately, this difference in complications remained highly significant for the native kidney group (P < 0.005), though not for the allograft group. When the effect of needle size alone was investigated, there was no significant difference in the incidence of complications when TN biopsies were compared with 14-gauge BG biopsies or when 14- and 18-gauge BG biopsies were compared with each other.

Biopsy, Needle↗
PubMed1994

Mass transfer area coefficients in children.

OBJECTIVE: Measurement of mass transfer area coefficients (MTAC) in children of different sizes to determine if solute transport varies with age and to compare with published adult values. DESIGN: Mass transfer area coefficients calculated from prospectively collected data in 28 selected patients. PARTICIPANTS: All children starting maintenance peritoneal dialysis at the Hospital for Sick Children. Selected patients were also studied if hospitalized for unrelated reasons. RESULTS: Mean MTAC values for creatinine and glucose were 4.0 and 4.5 mL/min, respectively, both considerably lower than adult values. When scaled per 70 kg body weight, these results were greater, and when scaled per 1.73 m2 surface area, they were lower than reported adult values. The MTAC/kg body weight was inversely correlated to age. CONCLUSIONS: Solute transport in children is directly related to age and does not approach adult values until later childhood. However, more rapid transport per unit body weight is observed in children and may reflect an increased effective peritoneal surface area.

Adolescent↗
PubMed1993

Respiratory function in the prune-belly syndrome.

Respiratory function was evaluated in 11 patients with prune-belly syndrome. Nine had evidence of gas trapping and six of restrictive lung disease. These abnormalities of lung function appear to be secondary to the musculoskeletal disorder associated with prune-belly syndrome rather than parenchymal lung disease.

Adolescent↗
PubMed1992

The peritoneal equilibration test in children.

The peritoneal equilibration test (PET) has been recommended in adults as a standardized means of estimating solute transport. Based on results of the PET, adult peritoneal permeability has been classified as high, high average, low average, and low. We performed a PET on 32 children aged 0.8 to 17.8 years (mean 9.3) using a dwell volume of 32 +/- 5 ml/kg of 2.5% dialysate. Dialysate to plasma (D/P) ratios for creatinine, urea, and sodium were calculated at two and four hours as were the ratios of dialysate glucose at two and four hours to the dialysate glucose at time 0 (D/Do). Stepwise logistic regression identified only the patients' age and D/Do glucose values at two hours as significant predictors of ultrafiltration. Net ultrafiltration after a four hour dwell could be predicted for 75% of children above 9.3 years, or whose D/Do glucose value at two hours was greater than 0.45. The mean and standard deviation values for D/Do glucose and D/P creatinine at four hours were 0.31 +/- 0.17 and 0.71 +/- 0.12, respectively. When children are characterized according to adult standards, at least 70% fall into the high or high average permeability categories.

Adolescent↗
PubMed1991

Low-dose and heparin-free hemodialysis in children.

Successful heparin-free hemodialysis has been reported in adults but not in children. A preliminary study was carried out to determine whether heparin-free hemodialysis was possible in children who were considered to have a high risk of bleeding, and if so, to identify the children in whom this technique might be expected to succeed. Of 28 heparin-free procedures, 21 (75%) were successful, a major clot developed in 4, and a minor clot occurred in 3. These children were 6.76 +/- 4.57 years old and weighed 20.7 +/- 11.3 kg. An activated clotting time (ACT) of less than 170 s was recorded in five of the six patients in whom clotting was observed (normal value 146 s with a range of 110-180 s). In a second prospective study, low-dose heparin was prescribed for patients with an ACT of less than 170 s, while the remaining children again underwent heparin-free dialysis. In this study only those patients with double-lumen vascular access and a predialysis systolic blood pressure greater than 80 mmHg were included. Their mean age was 12.25 +/- 4.61 years and their weights 32.9 +/- 19.3 Kg. In 28 of 31 (90%) procedures, no clotting was observed. Minor clotting developed during the remaining 3 procedures, all in one child who weighed 8.5 kg (the only child weighing less than 10 kg). Heparin (9.6 +/- 3.2 IU/kg body weight per hour) was administered during 18 successful procedures. This study shows that heparin-free hemodialysis is possible in children, particularly, but not exclusively, those with a coagulopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Pulmonary hemorrhage and necrotizing glomerulonephritis without glomerular immune deposits: report of two cases.

Two children with a syndrome of pulmonary hemorrhage and necrotizing, nonimmune glomerulonephritis are reported. A boy and girl, both of East Indian descent, developed recurrent lung infiltrates from the age of 3 months and 2 years, respectively. Both subsequently presented with pulmonary hemorrhage, fever, arthritis, hematuria, and nephrotic range proteinuria at 1.5 and 6 years of age, respectively. Renal biopsy in each case showed acute, severe, focal and segmental, necrotizing and crescentic glomerulonephritis without immune deposits. Subsequent renal biopsies revealed severe glomerular and tubulointerstitial scarring. No vasculitis or granulomas were seen on renal, skin, or lung biopsies. Antineutrophil cytoplasmic antibodies (ANCA) were not detected in sera taken 1.5 years in the boy and 3.5 years in the girl after the onset of renal disease. The boy was treated with prednisone, azathioprine, and plasmapheresis, but developed progressive renal impairment and commenced dialysis within 4 years. Subsequent to renal transplantation, he developed an immunoblastic lymphoma and died. The girl was treated initially with prednisone and later with cyclophosphamide. After 4 years, she had a normal glomerular filtration rate (GFR). While necrotizing nonimmune glomerulonephritis associated with pulmonary hemorrhage is rare, and cases are characteristically difficult to classify because of many overlapping features, it is possible that these children had a unique illness.

Child↗
PubMed1990

Linear growth and anthropometric and nutritional measurements in children with mild to moderate renal insufficiency: a report of the Growth Failure in Children with Renal Diseases Study.

During the control period of the Growth Failure in Children With Renal Diseases Study, investigators at 23 centers were able to observe and characterize growth and to make anthropometric and nutritional measurements in 82 children with mild to moderate renal insufficiency. As a multicenter, controlled clinical trial designed to study the relative efficacy of 1,25-dihydroxyvitamin D3 and dihydrotachysterol in the treatment of renal osteodystrophy, no prior vitamin D exposure and a creatinine clearance of 25 to 75 ml/min/1.73 m2 were criteria for entrance into the clinical trial. Ages ranged from 18 months to 11 years (mean 5.6 +/- 3.1 years), and distribution by age category was as follows: 38%, 1 to 3 years; 28%, 4 to 6 years; and 34%, 7 to 10 years. There was a 3:1 male/female ratio; 72% of the patients had congenital disease by the International Classification of Diseases (ninth revision). Mean creatinine clearance was 49.5 +/- 20 ml/min/1.73 m2. The C-terminal parathyroid hormone values (1121 +/- 1562 pg/ml) were well above 2 SD of the mean of a normal growing population of similar age. Parathyroid hormone values correlated with degree of renal insufficiency (r = -0.57) and with height by bone age but not with chronologic height or growth velocity. The bone age/height age ratio, a predictor of growth potential in normal children, was low for the entire series of patients (0.88 +/- 0.35) but failed to correlate with growth velocity and was negatively correlated with rising parathyroid hormone levels. Average values for height, weight, triceps skin fold, mid-arm muscle circumference, and body mass index were within 2 SD of the mean of the normal population, although measurements for the 1- to 3-year age group were significantly less than those of the older patients. Total energy intake averaged less than 86% of the recommended dietary allowances; total protein intake was more than 161% of the allowance. Nitrogen balance in 23 patients was positive and correlated most significantly with increasing energy intake (r = 0.6). Growth velocity, calculated from the interval gain during the month control period, averaged +0.3 SD, with the highest growth velocity z scores recorded for those with acquired disease. A growth velocity index, expressed as the slope of the regression between change in height SD and growth velocity z score, was used to describe the growth accomplished in the control period by age category.(ABSTRACT TRUNCATED AT 400 WORDS)

Age Determination by Skeleton↗