Favorable outcome of neonatal aortic thrombosis and renovascular hypertension

Fifteen children with renovascular hypertension as a result of aortic thrombosis were followed for a mean of 26 months (range 5 to 58 months) to determine outcome. As neonates, all patients had hypertension and elevated plasma renin activity. Of 11 patients studied with radionuclide renography and scintigraphy, 10 had abnormal renal blood flow; three had complete absence of unilateral perfusion. On follow-up examination all children were normotensive; five children ages 5 to 24 months required antihypertensive medication. Of 15 children, 14 had normal statural growth; all had normal serum creatinine, plasma renin activity, and calculated glomerular filtration rate values. Patients with complete absence of renal perfusion unilaterally remained functionally anephric; children with less severe perfusion deficits had improved perfusion as shown by radionuclide renography and scintigraphy. We believe that many patients with aortic thrombosis and renovascular hypertension who have had aggressive antihypertensive therapy in the neonatal period will have good renal function and increased perfusion to the affected kidney 2 years later.     

Development and usability of a feedback tool, “My Personal Brain Health Dashboard”, to improve setting of self-management goals among people living with HIV in Canada

Quality of Life Research - (1) To develop a personalized health outcome profile as a feedback tool to improve self-management in people living with chronic conditions such as HIV and (2) to...     

Sleep-disordered breathing in patients with myelomeningocele: the missed diagnosis

Moderate to severe sleep-disordered breathing (SDB) was identified in 20% (17 of 83) of children with spina bifida/myelomeningocele (SB/MM) at the Montreal Children's Hospital. The prevalence of SDB in patients with SB/MM elsewhere has not been determined. To establish current practices for identifying SDB in patients with SB/MM, questionnaires were sent to the coordinators of the 212 spina-bifida clinics in Canada and in the United States. Eighty-six (41%) questionnaires were returned, representing data on 13 349 patients. Although 67% of the responding centers reported availability of cardiorespiratory sleep studies, only 996 (7.5%) patients with SB/MM had been tested and only 418 (3.1%) patients had been diagnosed with SDB. Across clinics, the prevalence of SDB was directly related to the frequency of testing. Of 380 deaths over the past 10 years, SDB and sudden unexplained death during sleep were identified as the cause of death in 49 (12.8%) and 34 (8.9%) patients, respectively. Moderate to severe SDB may not have been identified in a significant number of patients with SB/MM because they have not been tested.     

T-Cell populations in liver and renal transplant recipients with infectious esophagitis

Individuals undergoing hepatic and renal transplants are susceptible to infections of the gastrointestinal tract, particularly the esophagus. The most common responsible agents are Candida and herpes simplex virus (HSV) with cytomegalovirus (CMV), Aspergillus, and other agents being regarded as unusual pathogens even in this unique population. Altered T-cell populations have been associated with CMV colitis in healthy homosexuals and in individuals with the acquired immunodeficiency syndrome (AIDS). Similarly, individuals with Epstein-Ban virus infections have altered T-cell populations. Whether these infections alter T-cell populations in infected individuals or the abnormalities in T-cell subpopulations occur first and enhance the likelihood of an infection in susceptible populations is as yet unknown. In this study peripheral blood T-cell populations in individuals before (19 patients) and after (47 patients) liver transplantation and after receiving a renal allograft (21 patients) were compared. Those individual having any symptoms related to esophageal disease underwent upper gastrointestinal endoscopy combined with mucosal biopsies, brushings, and cultures and were subdivided into those with and without infectious esophagitis. CMV esophagitis was found to be associated with an arithmetically decreased T-cell helper/supressor H/S) ratio principally due to an increase in the suppressor cell number. Such a reduction in the T_H/S ratio and in the number of circulating suppressor cells was not found in esophagitis due to either HSV or Candida and was unrelated to the serum cyclosporine level or prednisone dosage prescribed. Therefore the reduced H/S ratio due to an increase in the circulating suppressor cell number in patients with CMV esophagitis is probably due to the presence of the CMV infection per se rather than a factor predisposing the individual for a CMV infection.This work was supported by grants DK 2 R01 32556-05 and AA 066015-03.     

Ventilatory effects of almitrine bismesylate in congenital central hypoventilation syndrome

Patients with congenital central hypoventilation syndrome (CCHS) lack hypercapnic and hypoxic stimulation of ventilation but have demonstrated carotid body function in response to hyperoxia and to pharmacological stimulation with doxapram. This study investigated the ventilatory effects of almitrine bismesylate, a carotid body stimulant, in 12 patients with CCHS. Measurements of minute ventilation, tidal volume (VT), respiratory rate (RR) and transcutaneous PO2 (TCPO2) were taken before and after administration of 4.5 mg/kg and 6 mg/kg of almitrine. Twenty-four hour pharmacokinetic studies were performed in 7 patients who received 4.5 mg/kg and in 6 patients who received 6 mg/kg almitrine. There was no significant improvement in ventilatory and gas exchange parameters at either dose of almitrine despite appropriate peak serum concentration of the drug at the time of the studies. These results suggest that almitrine is not a useful ventilatory stimulant in children with CCHS.     

Creation and testing of the Geriatric Self-Efficacy Index for Urinary Incontinence

OBJECTIVES: To report on the content development, construct validity, and reliability testing of the Geriatric Self-Efficacy Index for Urinary Incontinence (GSE-UI).
DESIGN: Prospective cohort study.
SETTING: Six UI outpatient clinics in Quebec, Canada.
PARTICIPANTS: Community-dwelling incontinent men and women aged 65 and older.
MEASUREMENTS: Thirty-eight items were generated using a literature search and interdisciplinary panel of experts. Item reduction was achieved through field-testing with 75 older men and women with UI attending an information session. The final 20-item draft, measuring older adults' level of confidence in preventing urine loss, was administered to a new group of consecutive patients 1 week before and at the time of their first visit to the UI clinic to enable evaluation of test–retest reliability. A 3-day voiding diary, quantifying the frequency of UI, and the Incontinence Quality of Life questionnaire were used to test construct validity.
RESULTS: One hundred sixteen of 300 eligible patients (39%) participated (mean age±standard deviation 74±6, range 65–87). The GSE-UI items showed normal distributions and no ceiling effects. Self-efficacy scores ranged from 16 to 193 (mean 104±41, possible range 0–200) and correlated positively with quality of life scores ( r =0.7, P <.001) and negatively with UI severity ( r =−0.4, P <.001). Internal consistency for the GSE-UI was 0.94 (Cronbach alpha). Initial test–retest reliability of the 20 items using intraclass correlations ranged from 0.50 to 0.86.
CONCLUSION: The GSE-UI will enable measurement of whether a person's confidence in their ability to prevent urine loss is an important mechanism contributing to improvements in UI.     

Diaphragm pacing in infants and children. A life-table analysis of implanted components

Since 1976, we have implanted bilateral phrenic nerve electrodes for diaphragm pacing in 33 infants and children. This population includes 23 patients with congenital central hypoventilation syndrome (CHS), two with late onset CHS and hypothalamic dysfunction, three with hypoventilation associated with Chiari II malformation and myelomeningocele, and five with quadriplegia. Our experience, totalling 192 system-years and 96 patient-years of pacing, has enabled us to document the nature and frequency of problems related to the implanted components of the Avery Laboratories (S-232-1) pacemaker system when used in a pediatric population. By life table analysis, the mean time to need for replacement of any implanted component was 56.3 months. A total of 26 failures requiring component replacement occurred and were classified into four types: (1) receiver failure (15 cases), (2) electrode wire or wire insulation breakage (six cases), (3) infection requiring diaphragm pacer system removal (three cases), and (4) mechanical nerve injury (two cases). We conclude that the present diaphragm pacing system is effective but not without risk of biomedical component failure. The present system might be substantially improved by (1) a modified receiver design with a hermetic seal to prevent fluid penetration, (2) stronger, better insulated electrode wires, and (3) modifications of surgical technique and electrode type to prevent phrenic nerve damage.     

Pulse oximetry: Accuracy of methods of interpreting graphic summaries

Although pulse oximetry has been used to determine the frequency and extent of hemoglobin desaturation during sleep, movement artifact can result in overestimation of desaturation unless valid desaturations can be identified accurately. Therefore, we determined the accuracy of pulmonologists' and technicians' interpretations of graphic displays of desaturation events, derived an objective method for interpreting such events, and validated the method on an independent data set. Eighty-seven randomly selected desaturation events were classified as valid (58) or artifactual (29) based on cardiorespiratory recordings (gold standard) that included pulse waveform and respiratory inductive plethysmography signals. Using oximetry recordings (test method), nine pediatric pulmonologists and three respiratory technicians (“readers”) averaged 50 ± 11% (SD) accuracy for event classification. A single variable, the pulse amplitude modulation range (PAMR) prior to desaturation, performed better in discriminating valid from artifactual events with 76% accuracy (P < 0.05). Following a seminar on oximetry and the use of the PAMR method, the readers' accuracy increased to 73 ± 2%. In an independent set of 73 apparent desaturation events (74% valid, 26% artifactual), the PAMR method of assessing oximetry graphs yielded 82% accuracy; transcutaneous oxygen tension records confirmed a drop in oxygenation during 49 of 54 (89%) valid desaturation events. In conclusion, the most accurate method (91%) of assessing desaturation events requires recording of the pulse and respiratory waveforms. However, a practical, easy-to-use method of interpreting pulse oximetry recordings achieved 76–82% accuracy, which constitutes a significant improvement from previous subjective interpretations. Pediatr Pulmonol. 1996; 21:121–131. © 1996 Wiley-Liss, Inc.