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Biomedical subjects

Derek Stephens

Publications and source records attributed to Derek Stephens.

At least 19 recordsLinked to original sources

Pulmonary nodular opacities in children with hereditary hemorrhagic telangiectasia.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a rare inherited disorder of vascular endothelium that can result in the formation of pulmonary arteriovenous malformations (pAVMs). We observed that small pulmonary nodules, possibly representing early vascular malformations, are more common in these children than in the general population. OBJECTIVE: To describe and characterize the small pulmonary nodules seen on chest CT examination in the lungs of children with HHT. MATERIALS AND METHODS: We followed 19 children who had undergone chest CT as part of their initial diagnostic evaluation in the HHT clinic of a pediatric hospital. Chest CT scans were reviewed independently by two radiologists blinded to clinical data. Pulmonary nodules were analyzed according to lobar distribution, anatomic position in the lung (outer, mid, inner third), shape (round, linear, V- or Y-shaped, ill-defined), presence of overt AVMs, and nodule size ( 5 mm). We also reviewed a control group of chest CT scans performed on 25 age-matched children. RESULTS: A total of 35 pulmonary nodules were identified on the CT scans in 15 of the 19 children. Multiple nodules were seen in eight children (42%), solitary nodules were seen in seven children (37%) and no nodules were seen in the remaining four children (21%). The nodules were found to be nonspecific with regard to multiple factors other than their anatomic position within the lung. The chest CT scans of 2 of the 25 age-matched controls revealed a total of only four nodules, a significantly lower total (P = 0.0001 vs. children with HHT). CONCLUSION: Nonspecific nodules are commonly seen in children with HHT.

Adolescent↗

Parents' and patients' perceptions of postoperative appearance in adolescent idiopathic scoliosis.

STUDY DESIGN: A cross-sectional evaluation of patients after surgery for adolescent idiopathic scoliosis (AIS). OBJECTIVES: To determine the agreement between patients' and parents' perceptions of the patient's postoperative appearance and to compare those perceptions with physical and radiographic measures of deformity. SUMMARY OF BACKGROUND DATA: Improving cosmesis is an important aim of surgery. Patients' appearances may influence their evaluation of its outcome. METHODS: Physical and radiographic data were collected 2 years after surgery for 128 patients with AIS. Patients and parents independently rated shoulder blades, shoulders, waist, and overall appearance. Additionally, patients completed the Quality of Life Profile for Spinal Disorders (QLPSD). Agreement was evaluated with the weighted kappa statistic ranging between 0 and 1 where higher values indicate better agreement. RESULTS: Fair to moderate agreement was found between patient and parent ratings of the patient's shoulder blades (kappa = 0.39; 95% confidence interval [CI], 0.29-0.48), shoulders (kappa = 0.38; 95% CI, 0.26-0.50), waist (kappa = 0.45; 95% CI, 0.25-0.55), and overall appearance (kappa = 0.22; 95% CI, 0.04-0.40). Patients rated the appearance of their waist (P = 0.013) and overall appearance (P = 0.039) significantly worse than their parents. Patients' perceptions of their overall appearance had higher correlations with the body image subscale score (r = 0.45, P = 0.000) and the total quality of life score on the QLPSD (r = 0.37, P = 0.000) than did parents' perceptions of those same measures (r = 0.21, P = 0.025; and r = 0.08, P = 0.369, respectively). CONCLUSIONS: Radiographic and physical measures of deformity do not correlate well with patients' and parents' perceptions of appearance. Patients and parents do not strongly agree on the cosmetic outcome of AIS surgery. Therefore, given that the adolescents themselves undergo the surgery, patients' assessments of their deformity, rather than radiographic measures or parents' assessments, should play a major role in the evaluation of surgical success.

Adolescent↗

Influence of arm movement on central tip location of peripherally inserted central catheters (PICCs).

BACKGROUND: PICCs are increasingly employed in children. Some of their risks relate to the location of the central tip. Despite care when placing lines, they sometimes move. OBJECTIVE: To evaluate the influence of arm movement on the central tip location of PICCs placed in children. MATERIALS AND METHODS: The central tip location of PICCs was studied in 85 children, with the arm placed in six positions. The variables of side, vein, site and arm position were examined to measure the direction and range of tip movement. RESULTS: The side, site or vein used did not influence the range of movement of the central tip. Change in position of the arm had a significant influence on the central tip location, moving it an average of 2.2 rib spaces, a maximum of 3.5 ribs. Elbow bending and adduction of the arm caused the central tip to move deeper into the chest, compared to when the arm was straight and abducted 90 degrees . CONCLUSION: Arm position is the significant variable influencing PICC movement. Side, site and vein do not influence the range of movement significantly. Most PICCs descend deeper into the chest with arm adduction and elbow bending.

Adolescent↗

A randomized trial of ganciclovir versus ganciclovir plus immune globulin for prophylaxis against Epstein-Barr virus related posttransplant lymphoproliferative disorder.

BACKGROUND: Transplant recipients who are Epstein-Barr virus (EBV)-seronegative and receive organs from seropositive donors (EBV D+/R-) are at increased risk for posttransplant lymphoproliferative disorder (PTLD) and may benefit from antiviral prophylaxis. We performed a multi-center trial assessing two different antiviral regimens and their effect on EBV replication. METHODS: EBV D+/R- solid organ transplant recipients were randomized to receive either ganciclovir and placebo or ganciclovir and immunoglobulin (IG) for 3 months. Following this, patients were unblinded and IG patients received additional IG therapy until 6 months. EBV viral loads were done at least monthly. RESULTS.: Thirty-four patients (25 pediatric, 9 adult) completed the protocol (16 placebo; 18 IG). The incidence of a detectable viral load within the first year posttransplant was 13/16 (81.3%) in the ganciclovir arm vs. 13/18 (72.2%) in the ganciclovir and IG arm (P=0.8). Time to first detectable viral load, and time to high-level viral load were not significantly different. By repeated measures ANOVA analysis, and by estimation of viral load AUC, no significant effect of randomization group was observed on EBV viral loads. PTLD developed in 3 (8.8%) patients (all in IG arm; P=0.23). CONCLUSIONS: No significant difference in EBV viral load suppression was observed when ganciclovir was compared with ganciclovir and IG in high-risk EBV D+/R- patients.

Adolescent↗

Controlled delivery of high vs low humidity vs mist therapy for croup in emergency departments: a randomized controlled trial.

CONTEXT: Children with croup are often treated with humidity even though this is not scientifically based, consumes time, and can be harmful. Although humidity using the traditional blow-by technique is similar to room air and no water droplets reach the nasopharynx, particles sized for laryngeal deposition (5-10 microm) could be beneficial. OBJECTIVE: To determine whether a significant difference in the clinical Westley croup score exists in children with moderate to severe croup who were admitted to the emergency department and who received either 100% humidity or 40% humidity via nebulizer or blow-by humidity. DESIGN AND SETTING: A randomized, single-blind, controlled trial conducted between 2001 and 2004 in a tertiary care pediatric emergency department. PARTICIPANTS: A convenience sample of 140 previously healthy children 3 months to 10 years of age with Westley croup score of more than 1 or 2 or higher (scoring system range, 0-17); 21 families refused participation. INTERVENTION: Thirty-minute administration of humidity using traditional blow-by technique (commonly used placebo, n = 48), controlled delivery of 40% humidity (optimally delivered placebo, n = 46), or 100% humidity (n = 46) with water particles of mass median diameter 6.21 microm. MAIN OUTCOME MEASURE: A priori defined change in the Westley croup score from baseline to 30 and 60 minutes in the 3 groups. RESULTS: Groups were comparable before treatment. At 30 minutes the difference in the improvement in the croup score between the blow-by and low-humidity groups was 0.03 (95% confidence interval [CI], -0.72 to 0.66), between low- and high-humidity groups, 0.16 (95% CI, -0.86 to 0.53), and between blow-by and high-humidity groups, 0.19 (95% CI, -0.87 to 0.49). Results were similar at 60 minutes. Differences between groups in pulse and respiratory rates and oxygen saturation changes were insignificant, as were proportions of excellent responders; proportions with croup score of 0 at study conclusion; and proportions receiving dexamethasone, epinephrine, or requiring additional medical care or hospitalization. CONCLUSIONS: One hundred percent humidity with particles specifically sized to deposit in the larynx failed to result in greater improvement than 40% humidity or humidity by blow-by technique. This study does not support the use of humidity for moderate croup for patients treated in the emergency department. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00230841.

Administration, Inhalation↗

Postmortem orbital findings in shaken baby syndrome.

PURPOSE: To compare postmortem orbital findings in pediatric accidental head injury to Shaken Baby Syndrome (SBS). DESIGN: Retrospective study. METHODS SETTING: Institutional. STUDY POPULATION: Thirty-six patients underwent postmortem modified exenteration with sectioning of the orbital contents; 18 victims of SBS and 18 cases of fatal accidental head trauma. OBSERVATION PROCEDURE: In all cases of children who died from accidental head trauma, the orbital tissues were separated to expose the optic nerve sheath. Patients with gross evidence of hemorrhage within the sheath were included. All cases of SBS were included. After accidental head injury, exenteration was performed only if optic nerve sheath hemorrhage was suspected on gross examination. All children younger than 18 years old with head injury as primary cause of death were included. SBS is defined as having at least two of the following: (1) typical abnormal findings on neuroimaging, (2) typical skeletal injury, (3) retinal hemorrhages, (4) history of abusive shaking with or without blunt head trauma, or (5) an inadequate history to explain the observed injuries. MAIN OUTCOME MEASURE: Presence or absence of orbital hemorrhage. RESULTS: Orbital tissue injury is more common in SBS than accidental head trauma without orbital fracture. In addition, optic nerve sheath and optic nerve intradural hemorrhage are also significantly more common in SBS (P < .0001). CONCLUSIONS: Our study reports new evidence of injury to orbital tissues in SBS and supports the concept that these finding are due to unique acceleration-deceleration forces of this type of abusive head injury.

Child, Preschool↗

Assessment of change of optic nerve head cupping in pediatric glaucoma using the RetCam 120.

PURPOSE: To ascertain the interobserver agreement among various specialists when analyzing images of the optic nerve head taken with the RetCam 120 (Clarity Medical Systems, Inc., Pleasanton, CA) for assessing the progression of optic disk cupping in pediatric glaucoma. METHODS: Five observers compared pairs of RetCam 120 two-dimensional photographs from 64 eyes to identify whether or not changes in the optic disk had occurred. Observers included a pediatric glaucoma specialist, pediatric neurophthalmologist, strabismologist, pediatric ophthalmic imaging specialist, and pediatric ophthalmology fellow. Each was masked to the patient identity and clinical course. For each patient, the observers reviewed the photographs taken prior to therapy and at a minimum of 6 months following initiation of therapy. Interobserver variability was calculated and analysis conducted to identify influential variables. RESULTS: Poor agreement was noted between the observers. No significant association was obtained between agreement level and variables affecting photographic quality: variability of contrast and illumination, exposure and magnification, image clarity, presence of fluorescein on the cornea, and pixelation of the image with poor resolution. Raters noted problems with these image variables in 75.6% of the observations. The Kappa statistic obtained was kappa = 0.29 with overall proportion of agreement of p = 0.69, suggesting a fair agreement but not a moderate agreement. CONCLUSIONS: Comparison of RetCam 120 pediatric optic nerve head photographs, when performed subjectively by observers with different perspectives, and in isolation from clinical information, may not be a reliable indicator of cupping change. In addition, variations in image contrast, luminance, color, and pixelation pose significant challenges to agreement between observers. Comparison of RetCam 120 images should not be considered the sole criterion for monitoring pediatric glaucoma.

Adolescent↗

Parental understanding of the role of trainees in the ophthalmic care of their children.

OBJECTIVE: To examine parental knowledge and expectations regarding the roles of trainees involved in their child's ophthalmic care. DESIGN: Prospective survey. PARTICIPANTS: Parents of 128 children attending outpatient pediatric ophthalmology clinics at The Hospital for Sick Children in Toronto. METHODS: A questionnaire was given prospectively to parents (and 1 custodial grandparent). They were asked to identify, using a checklist, the roles and responsibilities of medical students, residents, and fellows and to explore their expectations regarding trainee participation using a multiple choice questionnaire. MAIN OUTCOME MEASURES: Parental knowledge and expectations regarding the roles and participation of medical trainees in the ophthalmic care of their children as measured by survey questionnaire. RESULTS: Parental knowledge about the roles of trainees was very limited with one exception: more than 95% knew that medical students are learning to be doctors and most had a good knowledge of the medical student role. More than 76% wanted to be asked specifically if they would allow trainees involved in their child's care. Seventy-five percent were happy to have capable trainees involved, provided that the trainees discuss all decisions with the responsible staff doctor. Parents wanted health care providers to identify themselves by name (77%) and position (86%). Only 3% did not want trainees involved in any part of their child's care. CONCLUSIONS: Although parental knowledge regarding the relative roles of trainees is poor, parents generally are willing to have trainees involved in their child's medical and surgical care, provided they are adequately supervised and that the parent is aware of their participation.

Adolescent↗

Weight gain in craniopharyngioma--a model for hypothalamic obesity.

OBJECTIVES: To evaluate (1) the pattern of post-operative weight gain and (2) the risk factors associated with the development of post-operative weight gain and obesity in children treated for craniopharyngioma. STUDY DESIGN: The records of 43 children who had primary craniopharyngioma resection were reviewed. Neurological, endocrine, anthropometric and radiological risk factors for the development of obesity and for post-operative increase in BMI SDS were analyzed. RESULTS: Twenty-five patients (58%) became obese post-operatively. Obesity was significantly associated with higher BMI SDS at presentation and pre-operative hydrocephalus (p < 0.05). Increased BMI SDS from 0-12 months was significantly associated with post-operative MRI evidenced hypothalamic damage and higher BMI at presentation (p < 0.05). CONCLUSIONS: Children who developed hypothalamic obesity had a significant, rapid BMI increase over the first 6 months, followed by stabilization, with no regression of BMI SDS.

Adolescent↗

High-dose inhaled fluticasone does not replace oral prednisolone in children with mild to moderate acute asthma.

BACKGROUND: Inhaled corticosteroids are not as effective as oral corticosteroids in school-aged children with severe acute asthma. It is uncertain how inhaled corticosteroids compare with oral corticosteroids in mild to moderate exacerbations. PRIMARY OBJECTIVE: The purpose of this work was to determine whether there is a significant difference in the percentage of predicted forced expiratory volume in 1 second in children with mild to moderate acute asthma treated with either inhaled fluticasone or oral prednisolone. METHODS: This was a randomized, double-blind controlled trial conducted between 2001 and 2004 in a tertiary care pediatric emergency department. We studied a convenience sample of 69 previously healthy children 5 to 17 years of age with acute asthma and forced expiratory volume in 1 second at 50% to 79% predicted value; 41 families refused participation. Albuterol was given in the emergency department and salmeterol was given after discharge to all patients, as well as either 2 mg of fluticasone via metered dose inhaler and valved holding chamber in the emergency department plus 500 microg twice daily via Diskus for 10 doses after discharge (fluticasone group, N = 35) or 2 mg/kg of oral prednisolone in the emergency department plus 5 daily doses of 1 mg/kg of prednisolone after discharge (prednisolone group, N = 34). We measured a priori defined absolute change in percent predicted forced expiratory volume in 1 second from baseline to 4 and 48 hours in the 2 groups. RESULTS. At 240 minutes, the forced expiratory volume in 1 second increased by 19.1% +/- 12.7% in the fluticasone group and 29.8% +/- 15.5% in the prednisolone group. At 48 hours, this difference was no longer significant (estimated difference: 4.0 +/- 3.4; P = .14). The relapse rates by 48 hours were 12.5% and 0% in the fluticasone group and prednisolone group, respectively. CONCLUSION: Airway obstruction in children with mild to moderate acute asthma in the emergency department improves faster on oral than inhaled corticosteroids.

Administration, Inhalation↗

Vascularity and angiogenesis as predictors of growth in optic pathway/hypothalamic gliomas.

OBJECT: The authors' aim in conducting this study was to investigate retrospectively the prognostic significance of angiogenic features in optic pathway/hypothalamic gliomas (OPHGs) in children. METHODS: Patients were identified in whom a diagnosis of OPHG was made using pathological analysis at the Toronto Hospital for Sick Children between 1985 and 2002. Tumor specimens were reviewed for diagnostic accuracy and adequacy of the specimen. Sections were immunostained with factor VIII to assess microvessel density (MVD). A ratio of alpha-smooth muscle actin to factor VIII immunostaining was calculated to arrive at a vascular maturity index (VMI). Vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) immunostaining were performed to evaluate angiogenic factors. In addition, the MIB-1 labeling index (LI) was used to assess proliferation. These factors were evaluated with respect to progression-free survival (PFS). Forty-one of 60 patients originally identified had adequate samples and follow up for inclusion in the study. Of these, eight patients had coexisting neurofibromatosis Type 1. Twenty-eight patients experienced tumor progression after the initial treatment (surgery with or without adjuvant treatment). Thirty-eight patients are still alive. A high MVD (> 21 vessels/1.2 mm2) was associated with a significantly higher rate of progression compared with a low MVD (< 21 vessels/1.2 mm2; p = 0.017). Microvessel density was also predictive of reduced PFS on multivariate analysis stratified for extent of resection (p = 0.04), and VMI as well as intensity and distribution of VEGF and VEGFR staining and the MIB-1 LI were not significantly associated with PFS. CONCLUSIONS: These findings suggest that MVD is the best current predictor of PFS in incompletely resected OPHGs. This information highlights the importance of angiogenesis in regard to low-grade gliomas.

Adolescent↗

Factors predicting the outcome of primary clubfoot surgery.

BACKGROUND: We aimed to determine the rate of further surgery, the functional outcome and the factors associated with outcome after primary clubfoot surgery. METHOD: We conducted a retrospective study of a cohort of all children who were less than 2 years of age at the time of surgery for idiopathic clubfoot deformity at the Hospital for Sick Children, Toronto, Ont., a tertiary care pediatric hospital. Of the 91 families who could be contacted, 63 agreed to return. The children's charts were reviewed, and their feet were given a Functional Rating System (FRS) score. RESULTS: Of the original operated population (n = 126), 75% were male and 41% had bilateral clubfoot. The average age at the time of surgery was 8 months, and the mean follow-up was 80.6 months. Further surgery was performed in 19% of cases. The mean FRS outcome score was 79. On average, the FRS score increased by 1.9 points as age at the time of surgery increased by 1 month. Only the presurgical talocalcaneal index was associated with the need for further surgery. CONCLUSION: The need for further surgery was 19% overall. Children who had surgery closer to 12 months of age had better functional results. Therefore, surgery should probably be performed in the second, rather than the first, 6 months of life.

Child↗

Clinical responsiveness of self-report functional assessment measures for children with juvenile idiopathic arthritis undergoing intraarticular corticosteroid injections.

OBJECTIVE: The Childhood Health Assessment Questionnaire (CHAQ), Juvenile Arthritis Functional Assessment Report (JAFAR), and Juvenile Arthritis Functional Status Index (JASI) are widely used functional measures for juvenile idiopathic arthritis (JIA) that differ in content, format, and completion time. We compared the responsiveness and child-parent agreement of the JAFAR, CHAQ, and JASI in a prospective, multicenter study. METHODS: Children and adolescents from 5 rheumatology centers were enrolled. Subjects were about to undergo therapy (intraarticular corticosteroid injections [IAS] and methotrexate or hip surgery (MTX/hip]) expected to produce a functional improvement. All subjects were studied before the intervention and at 6 weeks and 6 months posttreatment. At each study visit, the 3 measures were administered in randomized, balanced order to both parents and children. RESULTS: A total of 92 subjects (mean age 12.8 years) were enrolled in the study, 74 of which were in the IAS group. The responsiveness of all 3 measures was moderate to strong. The standardized response mean at 6 weeks for the IAS group on the JAFAR, CHAQ, and JASI was 0.41 (95% confidence interval [95% CI] 0.18, 0.64), 0.70 (95% CI 0.47, 0.93), and 0.36 (95% CI 0.13, 0.59), respectively. The CHAQ was somewhat more responsive to change at 6 weeks (IAS group: relative efficiency 0.34 [JAFAR], 0.27 [JASI]), but less responsive at 6 months (MTX/hip group: relative efficiency 5.1 [JAFAR], 3.9 [JASI]). All 3 questionnaires showed acceptable parent-child agreement, and overall, there were few differences between the 3 questionnaires. CONCLUSION: The functional outcome measures currently used for JIA are all adequately responsive for use in trials or in the clinic setting. The choice of which measure to use should therefore be based on the time available for completion, the intended clinical/research use, and the depth of content required.

Adolescent↗

Beneficial effect of oral sildenafil therapy on childhood pulmonary arterial hypertension: twelve-month clinical trial of a single-drug, open-label, pilot study.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a progressive and fatal disease. Sildenafil is a type 5 phosphodiesterase inhibitor and pulmonary vasodilator. Therefore, we hypothesized that sildenafil would improve distance walked in 6 minutes and hemodynamics in children with PAH. METHODS AND RESULTS: After baseline assessment of hemodynamics by cardiac catheterization and distance walked in 6 minutes, we administered oral sildenafil at 0.25 to 1 mg/kg 4 times daily to 14 children (median age, 9.8 years; range, 5.3 to 18). Diagnoses were primary (n=4) and secondary (n=10) PAH. We repeated the 6-minute walk test at 6 weeks and at 3, 6, and 12 months (n=14) and cardiac catheterization (n=9) after a median follow-up of 10.8 months (range, 6 to 15.3). During sildenafil therapy, the mean distance walked in 6 minutes increased from 278+/-114 to 443+/-107 m over 6 months (P=0.02), and at 12 months, the distance walked was 432+/-156 m (P=0.005). A plateau was reached between 6 and 12 months (P=0.48). Mean pulmonary artery pressure decreased from a median of 60 mm Hg (range, 50 to 105) to 50 mm Hg (range, 38 to 84) mm Hg (P=0.014). Median pulmonary vascular resistance decreased from 15 Wood units m2 (range, 9 to 42) to 12 Wood Units m2 (range, 5 to 29) (P=0.024). CONCLUSIONS: Oral sildenafil has the potential to improve hemodynamics and exercise capacity for up to 12 months in children with PAH. Confirmation of these results in a randomized, controlled trial is essential.

Adolescent↗

Effect of carbon dioxide on systemic oxygenation, oxygen consumption, and blood lactate levels after bidirectional superior cavopulmonary anastomosis.

OBJECTIVE: We sought to assess the effects of four different CO2 tensions on systemic oxygenation, oxygen consumption, and arterial blood lactate levels early after bidirectional superior cavopulmonary anastomosis. DESIGN: Prospective study. SETTING: Quaternary pediatric cardiac critical care unit. PATIENTS: Nine children aged 2-23 months (median, 7 months). INTERVENTIONS: All patients were sedated, muscle relaxed, and mechanically ventilated. Baseline Paco2 was adjusted to 35 mm Hg by changing tidal volume. CO2 was added via the inlet port of the ventilator to maintain the Paco2 at 45 and 55 mm Hg. Measurements were repeated after discontinuing additional CO2 gas at a Paco2 of 40 mm Hg. Arterial blood gases and lactate were measured at each level of Paco2. We measured oxygen consumption continuously by respiratory mass spectrometry. MEASUREMENTS AND MAIN RESULTS: Mean (95% confidence interval) Paco2 increased from 35 (34-36) to 45 (44-46) to 55 (54-56) mm Hg (4.7 [4.5-4.9] to 6 [5.7-6.3] to 7.3 [7.2-7.4] kPa), arterial pH decreased from 7.43 (7.39-7.47) to 7.35 (7.31-7.39) to 7.28 (7.24-7.32). Pao2 increased from 36 (32-40) to 44 (40-48) to 50 (45-55) mm Hg (4.8 [4.3-5.3] to 5.9 [5.4-6.4] to 6.7 [6.2-7.2] kPa), and oxygen saturation increased from 72% (67-79%) to 77% (73-81%) to 80% (76-84%). Oxygen consumption decreased significantly, with each increase in Paco2, from 146 (125-167) to 132 (112-152) to 126 (107-145) mL.min.m (p = .0001), and lactate decreased from 1.5 (1-2.0) to 1.2 (0.8-1.6) to 0.8 (0.5-1.1) mmol/L (p < .01). These changes returned toward baseline at a Paco2 of 40 mm Hg. CONCLUSIONS: Moderate hypercapnia with respiratory acidosis improved arterial oxygenation and reduced oxygen consumption and arterial lactate levels, thus improving overall oxygen transport in children after bidirectional superior cavopulmonary anastomosis.

Carbon Dioxide↗

Risk factors for post-transplant lymphoproliferative disorder in pediatric patients: a case-control study.

Post-transplant Lymphoproliferative Disorder (PTLD) because of the Epstein-Barr Virus (EBV) is a major concern after pediatric transplantation. The group at greatest risk is EBV-seronegative recipients who receive EBV-seropositive organs. Additional risk factors remain to be determined, including those among EBV-seropositive recipients. In this case-control study, PTLD cases were biopsy-proven over a period of 4 yr (1997-2000, inclusive). Each case was matched with 2 controls, based on the type of organ transplanted and the period of transplantation (+/-1 yr). Variables compared between cases and controls included those relating to the clinical and virologic profiles and immunosuppressive therapy. Twenty-two cases of PTLD were diagnosed during the study period. PTLD cases occurred at a median of 22.8 months post-transplantation (range 1-131). The median age of cases was 26.2 months (range 6.1-194) compared with 47.4 months (range 0.8-202.2) for controls (p = 0.93). Cases had a higher mean baseline EBV load compared with controls (3.1 log(10) (s.d. +/- 1.0) vs. 1.6 log(10)/10(6) PBMCs (s.d. +/- 1.4), with every 1 log increase in viral load resulting in a three times increase in the likelihood of PTLD (p < 0.007). Close to one in four cases of PTLD were EBV-seropositive pretransplantation. These seropositive recipients tended to be older patients with a trend to a worse outcome compared with their seronegative counterparts. The occurrence of PTLD was not associated with the use of any specific immunosuppressants. A significant proportion of PTLD cases occurred among EBV-seropositive transplant recipients, with a tendency towards an unfavorable outcome. Besides EBV-seronegative recipients who receive seropositive organs, some EBV-seropositive pediatric patients are at risk of PTLD. Additional studies are warranted to further define the factors associated with PTLD in EBV-seropositive transplant recipients.

Adolescent↗

Darbepoetin alfa (Aranesp) in children with chronic renal failure.

BACKGROUND: Darbepoetin alfa use has been reported in 7 children with chronic renal failure (CRF). Our objective was to evaluate the efficacy and safety of darbepoetin and determine a therapeutic dose in a larger sample of children with CRF. METHODS: Twenty-six children with chronic renal insufficiency (CRI) GFR <30 mL/min/1.73 m(2), on peritoneal dialysis (PD) or hemodialysis (HD) entered a prospective, open-label study of darbepoetin. Seven ineligible children who underwent the same evaluation were analyzed retrospectively. The starting dose was 0.45 microg/kg/week. IRB/REB approval and informed consent were obtained. The primary outcome measure was hemoglobin (Hb) response within a target range of 10.0 to 12.5 g/dL between 8 and 12 and 20 and 28 weeks. RESULTS: Thirty-three children (15 CRI, 9 HD, 9 PD; aged 1-17 years) were enrolled in the study. Ten patients dropped out (3 before 12 weeks and 7 before 28 weeks), none due to darbepoetin. Mean Hbs were 11.8 and 11.4 between weeks 8 and 12 and 20 and 28, respectively; the proportion of patients with Hb values >10.0 g/dL was 97% and 91% in the same intervals. No effect of grouping patients into CRI, HD, or PD or prospective versus retrospective was observed. One of 13 serious adverse events (hypertension) was possibly related to darbepoetin; 8/14 children reported injection-site pain. At 12 and 28 weeks, respectively, 73% and 87% were receiving darbepoetin less than once weekly. CONCLUSION: A dose approximating 0.5 microg/kg/week of darbepoetin effectively treats anemia in children with chronic renal failure; for many, this may be proportionately increased and injected less than once weekly.

Adolescent↗

Gas distribution in intraabdominal and pelvic abscesses on CT is associated with drainability.

OBJECTIVE: Intraabdominal and pelvic abscesses are treated by percutaneous image-guided drainage, under sedation or general anesthesia. This study attempts to determine if the CT features of gas distribution are associated with "drainability." Our premise was that gas may be trapped deep in a collection as bubbles, if the material is thick. Gas may rise to the surface if the material is thin, forming either an air-fluid level or superficial bubbles. MATERIALS AND METHODS: Patients with intraabdominal and pelvic abscesses were identified by the interventional radiology database, after research ethics board approval. Patients without prior CT were excluded. The imaging and clinical records were analyzed retrospectively. Intracollection gas distribution was recorded as superficial bubbles, deep bubbles, or air-fluid levels. Collections were classified accordingly: type 1, air-fluid levels; type 2, superficial or deep bubbles and air-fluid levels; type 3, superficial bubbles; type 4, deep bubbles; and type 5, no gas. RESULTS: One hundred five abscesses were examined in 61 patients, ranging in age from 2-17 years. Eight of 8 of type 1, 16 of 16 of type 2, 19 of 21 of type 3, 8 of 13 of type 4, and 43 of 47 of type 5 were drainable. The abscesses of all patients with an air-fluid level were drainable. Of abscesses with deep bubbles, 61.5% were drainable, versus 90.5% of those with superficial bubbles. Of those with superficial gas (superficial bubbles or air-fluid levels), 95.6% were drainable. In comparison with superficial gas, abscesses with deep trapped gas were associated with a longer duration of drainage, longer hospital stay, lower percentage of successful drainage, and higher percentage of residual collections. The difference is significant for drainability (p = 0.0048; p = 0.0331 after statistical adjustment for multiple testing). CONCLUSION: Distribution of gas in an intraabdominal or pelvic abscess is associated with drainability. Abscesses with superficial gas (superficial bubbles or air-fluid levels) have a greater chance of being drained successfully than do abscesses with deep trapped gas.

Abdominal Abscess↗