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Biomedical subjects

R Whyte

Publications and source records attributed to R Whyte.

At least 19 recordsLinked to original sources

Improved outcome of preterm infants when delivered in tertiary care centers.

OBJECTIVE: Previous studies that compared outcomes of infants born outside tertiary care centers (outborn) with those born in tertiary care centers (inborn) did not account for admission illness severity and perinatal risks. The objective of this study was to examine whether outborn status is associated with higher mortality and morbidity, after adjustment for perinatal risks and admission illness severity (using the Score for Neonatal Acute Physiology, Version II [SNAP-II]) among preterm infants who were admitted to Neonatal Intensive Care Units (NICUs). METHODS: Logistic regression analysis was used to compare the risk-adjusted outcomes of 3769 singleton infants born at or before 32 weeks' gestation, who were admitted to 17 Canadian NICUs during 1996-1997. RESULTS: Outborn and inborn infants had significantly different gestational ages, perinatal risk factors (maternal hypertension, prenatal care, antenatal corticosteroid therapy, 5-minute Apgar score, delivery type, small for gestational age) and admission SNAP-II. Outborn infants were at higher risk of death (adjusted odds ratio [OR] 1.7, 95% confidence interval [CI] 1.2, 2.5), grade III or IV intraventricular hemorrhage (adjusted OR 2.2, 95% CI 1.5, 3.2), patent ductus arteriosus (adjusted OR 1.6, 95% CI 1.2, 2.1), respiratory distress syndrome (adjusted OR 4.8, 95% CI 3.6, 6.3), and nosocomial infection (adjusted OR 2.5, 95% CI 1.9, 3.3), even after adjusting for perinatal risks and admission illness severity. CONCLUSIONS: Outborn infants were less mature and more ill than inborn infants at NICU admission. However, even after adjustment for perinatal risks and admission illness severity, inborn infants had better outcomes than outborn infants. Our results support in-utero transfer of high-risk pregnancies to a tertiary level facility.

APACHE↗

Transport risk index of physiologic stability: a practical system for assessing infant transport care.

OBJECTIVES: To develop and validate a practical, physiology-based system for assessment of infant transport care. STUDY DESIGN: Transport teams prospectively collected data, before and after transport, from 1723 infants at 8 neonatal intensive care units (NICUs) from 1996 to 1997. We used logistic regression to derive a prediction model for mortality within 7 days of NICU admission and develop the Transport Risk Index of Physiologic Stability (TRIPS). We validated TRIPS for prediction of 7-day mortality, total NICU mortality (until discharge), and severe (> or =grade 3) intraventricular hemorrhage. RESULTS: TRIPS comprises 4 empirically weighted items (temperature, blood pressure, respiratory status, and response to noxious stimuli). TRIPS discriminated 7-day NICU mortality and total NICU mortality from survival with receiver operating characteristic areas of 0.83 and 0.76, respectively. There was good calibration across the full range of TRIPS scores and gestational age groups. Increase and decrease in TRIPS scores after transport were associated with increased and decreased mortality, respectively. The receiver operating characteristic area for TRIPS prediction of severe intraventricular hemorrhage was 0.74. Addition of TRIPS improved performance of prediction models in which gestational age and baseline population risk variables were used. CONCLUSIONS: TRIPS is validated for infant transport assessment.

APACHE↗

Variations in practice and outcomes in the Canadian NICU network: 1996-1997.

BACKGROUND: Previous reports of variations in outcomes among neonatal intensive care units (NICUs) examined only specific subpopulations of interest (eg, very low birth weight [VLBW] infants <1500 g of birth weight [BW]). OBJECTIVES: We report on current practice and outcomes variations in a population-based national study of Canadian NICUs from January 8, 1996 to October 31, 1997. METHOD: Information on 20 488 admissions to 17 tertiary level NICUs across Canada was prospectively collected by trained abstractors using a standard manual of operations and definitions. Data were verified and analyzed in concert with a steering committee comprising experienced researchers and neonatologists. Patient information included demographic information, antenatal history, mode of delivery, problems at delivery, status of infant and problems at birth, illness severity (Clinical Risk Index for Babies, Score for Neonatal Acute Physiology, Score for Neonatal Acute Physiology-Version II), therapeutic intensity (Neonatal Therapeutic Intensity Scoring System [NTISS]), selected NICU practices and procedures, use of technology and resources, and selected patient outcomes. Patients were tracked until death or discharge home. RESULTS: The mean number of annual admissions to an NICU was 657, with 26% outborn infants. Fifty-three percent were <2500 g BW, 20% were <1500 g BW (VLBW), and 65% were preterm (<38 weeks' gestational age [GA]). Only 2% of mothers received no prenatal care. Antenatal steroids were given to 58%, but there was wide variation in use (23%-76%). Congenital anomalies were present in 14%, and 4% were small for GA (less than the third percentile). Admission illness severity was lowest among infants 33 to 37 weeks of GA and correlated with risk of death. Ninety-six percent of patients survived until discharge, but fewer survived at lower GA. No infant <22 weeks' GA survived. Seven percent of infants had at least 1 episode of infection, but 75% received antibiotics in the NICU. Forty-three percent received respiratory support, and 14% received surfactant. Nitric oxide was given to 150 term infants and to 102 preterm infants. Selected outcomes of VLBW infants were: survival rate (87%); chronic lung disease (26%); >/=stage 3 retinopathy of prematurity (ROP; 11%); >/=grade 3 intraventricular hemorrhage (IVH; 10%); nosocomial infection (22%); necrotizing enterocolitis (NEC; 7%). Sixty-nine percent of VLBW infants survived without major morbidity (>/=grade 3 IVH, chronic lung disease, NEC, >/=grade 3 ROP). The mean duration of NICU stay was 19 days. Forty-seven percent of infants were discharged from the hospital, and 43% were retrotransferred to a community facility before discharge home. Significant variation in practices and outcomes were observed in all aspects of NICU care. CONCLUSION: This study provides population-based information about NICU outcomes. Significant variation in NICU practices and outcomes was observed despite Canada's universal health insurance system. This national database provides valuable information for planning research, allocating resources, designing health and public policy, and serving as a basis for longitudinal studies of NICU care in Canada.

Birth Weight↗

Effect of polyethylene occlusive skin wrapping on heat loss in very low birth weight infants at delivery: a randomized trial.

OBJECTIVE: Significant evaporative heat loss in the very low birth weight infant can occur in the delivery room. We investigated the effect of polyethylene wrap applied immediately at birth (without drying) on rectal temperature measured at nursery admission. STUDY DESIGN: Sixty-two consecutive infants delivered at <32 weeks' gestation were stratified by gestational age and randomly allocated to resuscitation with polyethylene wrap. All infants were resuscitated under radiant warmers. Wraps were removed on nursery admission. Rectal temperature was taken by digital electronic thermometer. RESULTS: Fifty-nine of 62 recruited infants completed the study. Maternal temperature, delivery room temperature, transfer-incubator temperature, and time to admission were recorded. Use of occlusive wrapping resulted in a significantly higher admission rectal temperature in infants <28 weeks' gestation (difference in means = 1.9 C, P <.001). No significant difference was seen in admission rectal temperature in infants of 28 to 31 weeks' gestation (difference in means = 0.17 C, P =.47). All 5 deaths were in the nonwrap group (vs wrap, P =.04); their mean temperature was 35.1 C versus 36.5 C in survivors (P =.001). CONCLUSIONS: Occlusive wrapping of very low birth weight infants at delivery reduces postnatal temperature fall. This may result in a decreased mortality rate.

Apgar Score↗

Seasonal variation of Campylobacter types from human cases, veterinary cases, raw chicken, milk and water.

During August 1996 (winter) and February 1997 (summer), a total of 180 Campylobacter isolates from a restricted geographical area were obtained from human and veterinary cases, raw milk and chicken, and untreated water. Isolates were typed by Penner serotyping and pulsed-field gel electrophoresis (PFGE) of restriction enzyme-produced DNA fragments. Differences were noted between the August and February serotypes with the most, and fourth most frequently isolated serotypes in February being completely absent in August. Two other serotypes were more frequently found in the February isolates, while the reverse was true for two others. In contrast to the serotyping data, one PFGE restriction profile type was dominant in both seasons, and the pattern of distribution of isolates among the other restriction patterns was similar. Five groups of isolates in each month were indistinguishable by both typing methods. Only one group was common to both months. Another group, which was absent in August, dominated the February isolates. Marked differences in the types isolated in the two seasons were therefore evident. Some isolates from human cases were indistinguishable from others isolated from water and raw chicken, indicating possible routes of infection for humans.

Animals↗

Lung volume reduction surgery alters management of pulmonary nodules in patients with severe COPD.

OBJECTIVE: To examine the role of lung volume reduction surgery (LVRS) in expanding the treatment options for patients with single pulmonary nodules and emphysema. METHODS: Retrospective review of all patients undergoing LVRS at the University of Michigan between January 1995 and June 1996. Those undergoing simultaneous LVRS and resection of a suspected pulmonary malignancy formed the study group and underwent history and physical examination, pulmonary function tests, chest radiography, and high-resolution CT of the chest. If heterogeneous emphysema was found, cardiac imaging and single-photon emission CT perfusion lung scanning were performed. All study patients participated in pulmonary rehabilitation preoperatively. Age- and sex-matched patients who had undergone standard lobectomy for removal of pulmonary malignancy during the same period formed the control group. RESULTS: Of 75 patients who underwent LVRS, 11 had simultaneous resection of a pulmonary nodule. In 10 patients, the nodules were radiographically apparent with 1 demonstrating central calcification. Histologic evaluation revealed six granulomas, two hamartomas, and three neoplastic lesions (one adenocarcinoma, one squamous cell, and one large cell carcinoma). Preoperative FEV1 was 26.18+/-2.49% predicted in the LVRS group and 81.36+/-6.07% predicted (p=0.000001) in the control group, and the FVC was 65.27+/-5.17% predicted vs 92.18+/-5.53% predicted (p=0.002). Two LVRS patients had a PaCO2 >45 mm Hg while 11 exhibited oxygen desaturation during a 6-min walk test. Postoperative complications occurred in two LVRS patients and three control patients. The mean length of stay in the LVRS group (7.55+/-1.10 days) was not different than in the control group (8.81+/-1.56 days). Three months after LVRS and simultaneous nodule resection, FEV1 rose by 47%, FVC by 25%, and all study patients noted less dyspnea as measured by transitional dyspnea index. CONCLUSIONS: Simultaneous LVRS and resection of a suspected bronchogenic carcinoma is feasible and associated with minimal morbidity and significantly improved pulmonary function and dyspnea.

Aged↗

Psychotherapy--delayed.

The problem of the patient who presents repeatedly in distress, wanting help, is addressed with reference to one such patient. Paradoxically, by an admission that the patient could not be treated, treatment eventually became possible.

Adult↗

Regional diaphragmatic length and EMG activity during inspiratory pressure support and CPAP in awake sheep.

We examined diaphragmatic mechanics in awake sheep during quiet breathing (QB) and the randomized application of 5, 10, and 15 cmH2O continuous positive airway pressure (CPAP), inspiratory pressure support (IPS), and equal combinations of IPS and CPAP (IPS/CPAP). We measured esophageal, gastric, and transdiaphragmatic (Pdi) pressures and regional length, shortening, and electromyogram (EMG) activity of both costal and crural diaphragmatic segments. Segmental resting length normalized to QB decreased during 15 cmH2O CPAP (costal, 19.2 +/- 3.3%; crural, 7.5 +/- 2.1%; P < 0.05) and during 15/15 cmH2O IPS/CPAP (costal 25.3 +/- 4.8%, crural 9.9 +/- 2.6%; P < 0.05). Only during 15 cmH2O IPS did costal shortening fraction increase (67% QB; P < 0.05). Compared with QB, during 15 cmH2O CPAP, end-tidal CO2 increased 6 Torr, regional EMG activity increased threefold, and Pdi increased 58%. During 15 cmH2O IPS these values decreased 3 Torr, threefold, and 44% respectively, but during IPS/CPAP they remained unchanged. Expiratory gastric pressure (Exp-Pga) reached 4.3 +/- 0.4 cmH2O at 15 cmH2O CPAP, but during IPS/CPAP Exp-Pga was less (maximum of 1.7 +/- 0.4 cmH2O) than at comparable CPAP (P < 0.05), despite the shorter diaphragmatic length. We conclude that: 1) IPS alters the actions of the diaphragm during CPAP, 2) Exp-Pga is poorly coupled to diaphragmatic end-expiratory length, and 3) both IPS and the release of Exp-Pga assist active diaphragmatic shortening.

Animals↗

Perinatal hematological profile of newborn infants with candida antenatal infections.

We serially studied hematological profiles of 8 newborns with proven antenatal candida chorioamnionitis and funisitis. Candida albicans was cultured from various sources in the infants; blood and CSF cultures were all negative. Seven of the 8 were premature; 5 were sick. We statistically compared hematological data of the 'well' and 'sick' babies. The latter showed neutrophilia (mean 52,381 vs. 11,326/microliters, p less than 0.01) accompanied by significant elevation of nonsegmented granulocytes (NSG) and a NSG/neutrophil ratio greater than 0.3. Significant monocytosis (mean 7,836 vs. 2,869/microliters, p less than 0.01) and eosinophilia (mean 4,723 vs. 782/microliters, p less than 0.05) were also noted. Remarkable toxic granulations, vacuolization, and Döhle bodies were found in the neutrophils of the 'sick' newborns. Hematological profiles correlated with the infants' clinical condition.

Blood Cell Count↗

Evaluation of graduating neonatal nurse practitioners.

To compare the knowledge and problem-solving, communication, and clinical skills of graduating neonatal nurse practitioners (NNPs) and pediatric residents, a cohort study was conducted in a 33-bed tertiary-level neonatal intensive care unit in a 400-bed teaching hospital affiliated with a faculty of health sciences. Participants were all (n = 10) NNP graduates from the first 3 years of the educational program and 13 (87%) of 15 second-year pediatric residents. One hundred multiple-choice questions and 20 radiographic slides were used to test knowledge; a semistructured oral examination tested problem-solving skills; three simulated interactions with parents tested communication skills; and seven simulated procedures tested clinical skills. Graduating NNPs scored similarly to the pediatric residents on the multiple-choice questions (difference -3.4%; 95% confidence interval [CI] around difference -9.7, 2.9), radiographs (difference -1.4%; 95% CI -11.5, 8.7), oral examination (difference 2.8%; 95% CI -11.1, 16.7), communication skills (simulated parents assessment: difference 0.8%; 95% CI -4.2, 5.7; expert observer assessment: difference 5.8%; 95% CI -2.8, 14.3), and clinical skills (difference 7.4%; 95% CI -5.5, 20.2). The NNPs about to graduate from their educational program showed knowledge and problem-solving, communication, and clinical skills equivalent to those of second-year pediatric residents and are thus likely to deliver comparable care in the clinical setting. The results support the adoption of the NNP role.

Clinical Competence↗

Antigen protection of monoclonal antibodies undergoing labelling.

The effectiveness of a methodology designed to protect the antigen binding capacity of monoclonal antibodies undergoing labelling with a number of reagents was examined. The antigen binding sites of monoclonal antibodies were protected by complexing them with their antigen. Chemical modification with 6 mM of the water soluble Bolton-Hunter reagent of site protected monoclonal antibodies to glucoamylase resulted in antibodies that could tolerate a four-fold increase in reagent incorporation, without any loss of antigen binding capacity. Iodination of these antibodies (modified under site protected conditions) yielded over 70% increase in radioactivity incorporated in the active antibody fraction, compared with the incorporation into unprotected antibodies. Site protected labeling was found to be effective in retaining the antigen binding capacity of monoclonal antibodies modified with all reagents tested with the exception of chloramine-T.

Animals↗

Psychotherapy--a last resort.

A patient in whom a series of treatments of all sorts had failed was given two trials of psychotherapy over a prolonged period. Although the patient judged the trials of psychotherapy to be a failure, and therapy was terminated, he does seem to have matured, and his disturbed behaviour has ceased. The possible reasons for this are discussed.

Adult↗

Pulmonary thromboemboli after neonatal asphyxia.

Two surviving neonates with pulmonary thromboembolism, diagnosed by ventilation-perfusion lung scan, are described. Both infants had respiratory distress, and one had features consistent with persistent pulmonary hypertension of the neonate. These reports demonstrate that substantive pulmonary emboli can occur in neonates and may not be recognized without an appropriate level of clinical suspicion.

Asphyxia Neonatorum↗

Growth, metabolic response, and development in very-low-birth-weight infants fed banked human milk or enriched formula. I. Neonatal findings.

Banked human milk has been widely used, although its composition and nutritional adequacy for preterm infants are uncertain. We randomized 76 healthy infants of less than or equal to 1500 gm birth weight to ad lib feedings of frozen BHM or a protein-mineral-calorie-enriched formula (Similac Special Care) designed to sustain intrauterine accretion rates; BHM contained 2.2 gm fat/100 ml and 60 kcal/100 ml (gross energy). Infants fed BHM ingested more milk (197 vs 165 ml/kg/day) but less gross energy (118 vs 143 kcal/kg/day); grew less rapidly in weight (15 vs 30 gm/day), length (0.7 vs 1.1 cm/wk), and head circumference (0.8 vs 1.2 cm/wk); and were discharged at a lower weight (2200 vs 2348 gm) and older age (61 vs 47 day) than infants fed formula (P less than 0.02). At 37 weeks' postmenstrual age, infants fed BHM were less responsive to Brazelton inanimate stimuli (mean total score 5.0 vs 7.5; P less than 0.02). With few exceptions, blood amino acids, pH, and serum electrolyte values were similar in both groups. The different caloric intake of our feeding groups may explain only part of the large difference in growth rate. Donor milk should not be fed to preterm infants unless it has been analyzed and the feedings shown to provide a nutrient intake considered appropriate to the needs of these infants.

Body Weight↗

Psychiatric new-patient clinic non-attenders.

Non-attenders at a psychiatric new-patient clinic were seen and interviewed six weeks after the missed appointment, as were a group of controls who did attend. The non-attenders were more likely to have had frequent changes of occupation or belong to families where this was the case with the family breadwinner; a history of court conviction; and a history of previous psychiatric treatment. They were less likely to have improved since referral to the clinic; and to have a diagnosis of manic depressive psychosis, depressed type. The findings are discussed. There appears to be some self-selection, the most treatable patients keeping their appointments.

Bipolar Disorder↗