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Biomedical subjects

R O Hickman

Publications and source records attributed to R O Hickman.

At least 19 recordsLinked to original sources
PubMed2000

Asymptomatic inferior vena cava abnormalities in three children with end-stage renal disease: risk factors and screening guidelines for pretransplant diagnosis.

We report two children with end-stage renal disease (ESRD) found to have inferior vena cava (IVC) thrombosis at the time of renal transplantation. The children suffered from renal diseases that included congenital hepatic fibrosis and portal hypertension as part of their pathophysiology. Neither child had evidence of hypercoaguability or clinical symptoms of IVC thrombosis. Prior to transplantation, the renal replacement therapy consisted primarily of peritoneal dialysis. During their hospital courses, these children had central venous catheters placed for temporary hemodialysis, episodes of peritonitis and numerous abdominal surgeries. The medical literature to date has not identified a link between IVC thrombosis and portal hypertension, nor has an association between the patients' primary renal disease and IVC thrombosis been found. We also report the finding of asymptomatic IVC narrowing in a third patient with obstructive uropathy, colonic dysmotility and numerous abdominal surgeries. IVC narrowing was diagnosed by CT scan during his pretransplant evaluation. In this paper, we consider similarities between these three patients that may have predisposed each of them to asymptomatic IVC pathology, including large-bore central venous access as young children and/or recurrent scarring abdominal processes. A discussion regarding appropriate screening of the 'high-risk patient' for IVC pathology prior to kidney transplantation and surgical options for children with this rare complication are presented.

Catheterization, Central Venous↗
PubMed1999

Safety and efficacy of erythropoietin in children with chronic renal failure.

A prospective randomized study of the use of recombinant human erythropoietin (rHuEPO) in children with chronic renal disease was conducted to assess dosing requirements and side effects. Forty-four children with chronic renal failure, aged 4 months to 21 years, were studied. Twenty-five patients were pre dialysis, 10 on peritoneal dialysis, and 9 on hemodialysis. Patients received either 150 U/kg per week or 450 U/kg per week divided thrice weekly of rHuEPO for 12 weeks or until target hemoglobin (Hb) was attained. Dose was then adjusted to maintain a normal Hb. Eighty-two percent of patients reached target Hb by 7.9+/-5.6 weeks (mean+/-SD); 95% of patients in the high-dose group and 66% in the low-dose group reached target Hb within 12 weeks. The overall median rHuEPO dose at target Hb was 150 U/kg per week. Hemodialysis patients tended to require more rHuEPO to maintain a normal Hb (median 250 U/kg per week). Transfusion requirements and panel-reactive antibody levels decreased during the 12 weeks. Iron deficiency and/or hypertension occurred in 30% of children. In conclusion, rHuEPO at 150 U/kg per week is safe and effective in treating anemia in children with chronic renal disease.

Adolescent↗
PubMed1998

The central venous catheter as a source of medical chaos in Munchausen syndrome by proxy.

PURPOSE: The aim of this study was to determine what percentage of childhood central venous catheters (CVC) are placed in victims of Munchausen syndrome by proxy (MSBP) and to evaluate the clinical indications and complications of CVCs in MSBP. METHODS: Study design was by retrospective chart review. Data were obtained from the regional children's hospital and regional child abuse consultation network. Patients in the MSBP series were all children who on consultation were determined to be victims of MSBP, from 1974 through 1996. Patients in the central catheter series were all children who had central venous catheters placed 1991 through 1995, excluding children whose catheters were placed for cancer chemotherapy or for chronic renal failure. Consultation records of MSBP cases were abstracted noting the clinical characteristics of victims and perpetrators. Hospital procedure codes were reviewed for children who had CVCs placed. Those who had discharge diagnostic codes that commonly require CVC placement were not reviewed, but charts of children with diagnoses not usually requiring CVCs were evaluated. Descriptive statistics and chi2 and Fisher's Exact test were used for comparisons. RESULTS: Sixteen of ninety-three (17%) of MSBP victims had central lines, including two deaths caused by assault through the lines. Line sepsis occurred in 9 of 16 (56%) patients. Primary reasons for CVC were for administration of medicines that can normally be administered orally or subcutaneously (7) or for severe nutritional depletion (8). All but one of the children had symptoms of multiple organ system involvement. Siblings had frequently been victimized. The mean age of symptom onset was 19 months, yet the mean age at diagnosis was delayed until 82 months. All perpetrators were the mother. Fathers were usually physically or emotionally unavailable. Nearly one third of mothers had prior medical training and one third had themselves been victims of prior physical or sexual abuse. Ten of fifteen mothers previously exhibited Munchausen behavior themselves. Of children at our institution who had central venous catheter placement, 8 of 709 (1.1%) were MSBP victims. CONCLUSIONS: CVCs are frequently placed in MSBP victims for physiological problems, malnutrition, or failure to respond to normal treatments. Surgeons should consider requesting systematic evaluation for MSBP in patients seeking CVC placement for diagnoses not usually requiring CVCs lest they become unintentional collaborators in abuse of these children.

Adult↗
PubMed1994

Use of the Hickman-Crawford critical care catheter in marrow transplant recipients: a pulmonary artery catheter-adaptable central venous access.

OBJECTIVE: To describe the use of a modified 15.5-Fr double-lumen, tunneled right atrial catheter (Hickman-Crawford catheter) in adult bone marrow transplant recipients, that permits passage of a 5-Fr pulmonary artery catheter through the larger of the catheter's lumens. DESIGN: A case series review of the clinical experience with a modification of the existing central venous catheter design. SETTING: A bone marrow transplantation center. PATIENTS: Fourteen patients (weighing at least 50 kg body weight) undergoing bone marrow transplantation. Ages ranged from 18 to 64 yrs (median 40). There were nine male and five female patients. All patients, except for three who were receiving autologous marrow transplants, underwent allogeneic transplants. MEASUREMENTS AND MAIN RESULTS: Sixteen catheters were inserted into the subclavian vein in 14 patients. The catheters remained in place for a mean of 44 days (median 30; range 6 to 107) and 56% remained functional until removed an average of 60 days later at the time of death (n = 5) or discharge to home (n = 4). One catheter was accidentally dislodged by the patient and six catheters (38%) were electively removed, two because of infection and four because of mechanical occlusion or damage. The Hickman-Crawford catheter was used as venous access for insertion of 21 pulmonary artery catheters in 12 patients (twice in seven patients). Ninety percent of these insertions (19 of 21) were done without difficulty; use of a guidewire was required in the remaining two cases. No complications of pulmonary artery catheterization were seen. CONCLUSIONS: This experience illustrates that a tunneled right atrial catheter for long-term use can be employed safely and repeatedly for insertion of pulmonary artery catheters for central hemodynamic monitoring.

Adolescent↗
PubMed1991

Mitochondrial DNA deletion in a girl with manifestations of Kearns-Sayre and Lowe syndromes: an example of phenotypic mimicry?

Lowe oculocerebrorenal syndrome is an X-linked recessive disease whose locus has been assigned to Xp25. However, several reports of affected females without obvious chromosomal abnormalities suggest genetic heterogeneity of the Lowe phenotype. Although the biochemical defect in typical Lowe syndrome is not known, there is evidence suggesting that mitochondrial metabolism may be impaired. We have studied a girl who presented with an oculocerebrorenal syndrome, but later developed symptoms and signs of mitochondrial encephalomyopathy. Molecular genetic analysis of muscle mitochondrial DNA showed the presence of a population of partially deleted mtDNAs (heteroplasmy). The deletion was 7803 bp long and encompassed several genes encoding subunits of the respiratory chain enzymes. Our results suggest that mitochondrial DNA deletions may mimic several symptoms of the Lowe phenotype and reinforce the concept that a defect of mitochondrial metabolism could be involved in the pathogenesis of the X-linked disease.

Base Sequence↗
PubMed1990

Comprehensive management of renal failure in infants.

From 1986 through 1989, 23 infants (18 of whom were less than 30 days old) required peritoneal dialysis within their first 6 months of life. Modifications to conventional peritoneal dialysis included modified Silastic Tenckhoff catheters, peel-away sheaths for percutaneous insertion, automated peritoneal dialysis "cyclers," and generous omentectomy. With these modifications, there were no bowel perforations, and the infants were successfully dialyzed for prolonged periods. Eight of the 23 infants developed end-stage renal failure and were prepared for transplantation. All had gastrostomy tubes placed to supplement oral nutrition. Living, related transplantation was performed when the child weighted 10 kg. Four of the eight completed this protocol. One child with congenital nephrotic syndrome died before transplantation. One transplant was complicated by a technical problem (venous thrombosis), which resulted in allograft loss and return to peritoneal dialysis. Kidney function, growth, and development in the survivors were excellent.

Catheters, Indwelling↗
PubMed1990

Escherichia coli O157:H7 and the hemolytic uremic syndrome: importance of early cultures in establishing the etiology.

Fifty-two patients were studied prospectively to determine the etiology of postdiarrheal hemolytic uremic syndrome (HUS). Escherichia coli O157:H7 was isolated from 33 patients (63.4%). If stool obtained within 2 days of the onset of diarrhea was cultured for E. coli O157:H7, the recovery rate was 100%. This rate decreased to 91.7% and 33.3% if stool was cultured for this pathogen 3-6 or greater than or equal to 7 days, respectively, after diarrhea began. The culture-positive group was more likely to have had bloody diarrhea and fecal leukocytes and to have received transfusions than the culture-negative group but was otherwise similar in clinical characteristics. E. coli O157:H7 is the predominant pathogen associated with HUS in western Washington. Recovery of this pathogen is highly dependent on obtaining stool cultures within 6 days of onset of diarrhea.

Adolescent↗
PubMed1989

The increasing incidence of the hemolytic-uremic syndrome in King County, Washington: lack of evidence for ascertainment bias.

The annual incidence of the hemolytic-uremic syndrome was determined for the well-defined population of King County, Washington, between 1971 and 1986, inclusive, to ascertain temporal trends in the epidemiology of this disease. The average annual incidence rose from 0.69 cases per 100,000 children under age 15 years between 1971 and 1975 to 1.77 cases between 1976 and 1980 and 1.74 cases between 1981 and 1986. The mean hematocrits, platelet counts, and blood urea nitrogen and creatinine concentrations on admission were similar in all periods, as were the mean length of hospital stay and the proportions of patients requiring erythrocyte and/or platelet transfusions and dialysis. These results indicate that the increased incidence of hemolytic-uremic syndrome in childhood has been sustained in King County, Washington, and that this increase is not due to ascertainment bias caused by the diagnosis of less severely ill cases. Further investigations are needed to determine whether this increased incidence is being experienced in other populations and to assess strategies for the prevention of microangiopathic sequelae to hemorrhagic colitis.

Adolescent↗
PubMed1987

Use of arteriovenous shunts and right atrial catheters for daily granulocyte collection.

Between June 1982 and April 1984, 67 adult granulocyte donors were randomized to receive external arteriovenous shunts or modified right atrial catheters as vascular access for daily granulocyte collections using blood cell separators. Six of 32 donors with shunts and 2 of 35 donors with right atrial catheters experienced failure of the access method. Local infection occurred in one donor with a shunt and one donor with a right atrial catheter. Bacteremia occurred in one donor with a right atrial catheter. Specified whole blood flow rates of 50-65 ml/minute were achieved with 28 of 32 shunts and 29 of 35 right atrial catheters (P = NS). The majority of the donors in each group tolerated the vascular access without significant problems. This study demonstrates that modified right atrial catheters can be successfully used as method of vascular access for single donor granulocyte collection with blood cell separators.

Arteriovenous Shunt, Surgical↗
PubMed1987

Escherichia coli O157:H7 as the predominant pathogen associated with the hemolytic uremic syndrome: a prospective study in the Pacific Northwest.

During a 12-month period, 14 patients with the hemolytic uremic syndrome were identified in a prospective study of enteric pathogens associated with this disorder. Of the 12 patients with a diarrheal illness preceding the onset of hemolytic uremic syndrome, fecal Escherichia coli O157:H7 was detected in seven (58%), all of whom had bloody diarrhea. Half of the siblings of these patients had concurrent nonbloody diarrhea. No source for infection with this organism was identified. Enteric infection with E coli O157:H7 occurs in the majority of cases of hemolytic uremic syndrome following diarrheal illness in the Pacific Northwest and may represent a previously overlooked cause of hemolytic uremic syndrome in other locales. Evaluation of all cases of hemolytic uremic syndrome for enteric pathogens should routinely include cultures for E coli O157:H7 until results of additional studies clarify the distribution of agents associated with hemolytic uremic syndrome in different geographic regions. These findings may provide new opportunities for the design of therapeutic and preventive strategies in this disorder.

Adolescent↗
PubMed1987

Hemolytic uremic syndrome epidemiology: a population-based study in King County, Washington, 1971 to 1980.

We conducted a retrospective, population-based study of the hemolytic uremic syndrome of childhood in King County, Washington. The average annual incidence of hemolytic uremic syndrome between 1971 and 1980, inclusive, was 1.16 cases per 100,000 children younger than 15 years of age and increased during the decade and into the early 1980s. The highest annual incidence was in children less than 3 years of age (3.02 per 100,000 children) and was equal in black and white children. No demographic risk factors were associated with the incidence of this disease including population density, median family income, crowding in housing units, percentage of households with public water supply, and percentage of households with public sewers. Our data suggest that this disease is common, endemic, and increasing in incidence in King County, Washington.

Adolescent↗
PubMed1984

Granulocyte collection by continuous-flow centrifugation using arteriovenous shunts.

Two thousand nine hundred twenty-seven granulocyte collections were made using continuous-flow centrifugation with the Aminco Celltrifuge I, the Fenwal Celltrifuge II, and the IBM 2997. There were 231 recipients and 246 donors. In 32 patients attempts to provide daily granulocyte transfusions from a single donor were unsuccessful owing to clotting of the silastic-Teflon arteriovenous shunt. Repeated granulocyte donations produced severe anemia requiring red cell transfusions in all the females and most of the males who had previously donated marrow for transplantation. Granulocyte collections were similar when collected with the Celltrifuge I or the IBM 2997, but collections with the Celltrifuge II were smaller. Infusion of hydroxyethyl starch directly into whole blood as it entered the centrifuge increased granulocyte collections. Granulocyte collections decreased with increasing number of daily collections.

Arteriovenous Shunt, Surgical↗
PubMed1984

Hickman catheter infections in patients with malignancies.

The infectious complications associated with implantation of 1,088 Hickman catheters (HCs) in 992 patients reported in 18 published series are presented (including data on 129 previously unreported HCs from our own institution). HCs allow reliable long-term venous access (mean, 92.4 days) with low complication and infection rates (0.30 and 0.14 cases per 100 catheter days, respectively). Exit site infections were the most common form of infection encountered (45.5%), followed by septicemia alone (30.8%), tunnel infections (20.3%), and septic thrombophlebitis (3.5%). Staphylococcus epidermidis (54.1%) and S. aureus (20.0%) were the most common pathogens responsible for catheter infections. HC infections were associated with a low mortality rate (maximum rate of 0.5%). Risk factor analysis of 129 HCs demonstrated that catheter thrombosis was the major risk factor associated with development of catheter infection. Presence of fever, distant infection, neutropenia or antibiotic administration on the day of catheter insertion was not significantly associated with HC infection in this series (although there was a trend suggesting an increased risk of infection of HCs inserted during febrile episodes). Based on observations at our institution and from a review of the literature, tentative recommendations for management of the various types of HC infections are outlined.

Acute Disease↗
PubMed1983

Experience using central venous access for long-term hemodialysis. A new concept.

Central venous access for acute renal failure has been used for a number of years. The femoral vein and, more recently, the subclavian vein have been the routes of access. This technique has many advantages, however, it also has some significant limitations. We have recently been using a catheter for long- as well as short-term hemodialysis. The catheter is placed by means of a short incision through an opening in the internal jugular vein, and maneuvered so that the tip lies in the superior portion of the right atrium. After dialysis, the catheter is filled with heparin. The catheter then requires no additional care between between hemodialysis sessions. We have reported an experience of 50 patients in whom this catheter has been used. The complications have been remarkably few, and none were serious or fatal. At present, the patient using the catheter for the longest period of time has had it in position for approximately 19 months. We believe this technique provides a significant new choice among the ways in which hemodialysis can be achieved for short- or long-term needs.

Acute Kidney Injury↗
PubMed1982

Nutritional support in marrow graft recipients with single versus double lumen right atrial catheters.

To determine the comparative efficiency of single and double lumen right atrial catheters, marrow transplant recipients were evaluated during a 26-month period retrospectively. Calories and protein infused as a percent of the amount ordered was calculated by week from initiation of total parenteral nutrition through day 28 posttransplantation. Data from 1979 reflected initial technical difficulties, showing no significant difference between groups. Patients with double lumen catheters received significantly greater (P less than 0.05) calories during the first 3 weeks after transplant in 1980 and 1981. A similar trend was seen in protein infusion. A significantly greater proportion of patients with double lumen catheters received at least 90% of the ordered total parenteral nutrition during the first 3 weeks after transplant in both years. These results suggest that the ability to infuse total parenteral nutrition in ordered amounts can be accomplished using the double lumen catheter.

Adolescent↗