Biomedical subjects

D L Stewart

Publications and source records attributed to D L Stewart.

95 records · Page 6Linked to original sources

PubMedDate not supplied

Drug screening in newborns and mothers using meconium samples, paired urine samples, and interviews.

We evaluated the prevalence of illicit substance abuse by comparing drug screening results derived from meconium, urine pairs, and maternal interview. Mother/infant pairs (580) were entered into this blinded, prospective study. Prevalence of illicit substance abuse was 3.4%. The lack of prenatal care correlated with the use of cocaine (p < 0.001). Neonates born to cocaine-using mothers were more likely to be premature, to have a lower birth weight, decreased length, and smaller head circumference using unpaired t test (overall p < 0.05 using Bonferroni method for simultaneous inference). For mother/infant pairs who had positive drug screening for cocaine, the interview, maternal urine sample, and meconium sample showed equal sensitivity, although the newborn urine showed poor correlation. We suggest that the newborn urine sample could be deleted from newborn drug screening, and lack of perinatal care may serve as a marker of substance abuse.

Cocaine↗

PubMedDate not supplied

Use of two-dimensional and contrast echocardiography for venous cannula placement in venovenous extracorporeal life support.

The objective of this study was to determine the efficacy of two-dimensional and contrast echocardiograms to identify venous cannula position. Sequential sampling of 20 infants was evaluated by contrast echocardiography after meeting institutional criteria for extracorporeal life support. Each infant was placed on venovenous extracorporeal life support using a double-lumen cannula. After surgical placement was thought to be satisfactory, optimal two-dimensional images of the cannula were obtained via a subxiphoid or apical view and 2 ml agitated normal saline were injected rapidly into the nearest infusion port. Patient demographics and mixed venous saturations were noted. Distance of the venovenous cannula to tricuspid valve and distance of the venovenous cannula from the intra-atrial septum was recorded. Echocardiograms were available for review on 18 of the 20 patients. Position of the venovenous cannula in relationship to the tricuspid valve was as follows: < 5 mm (8); 5-10 mm (5); > 10 mm (5). Mixed venous saturations decreased, which indicated less recirculation when the orientation of the tip of the cannula was toward the lateral wall in those who required repositioning. The authors conclude that two-dimensional and contrast echocardiography aid in the positioning of the venovenous cannula. Satisfactory position is approximately 5 mm from the tricuspid valve, with orientation toward the lateral wall of the right atrium.

Catheterization, Central Venous↗

PubMedDate not supplied

The use of a second course of extracorporeal membrane oxygenation in neonatal patients.

Extracorporeal membrane oxygenation (ECMO) has been successful in rescuing near term or term infants in cardio-respiratory failure that results from a reversible disease process. In most cases, only one course of ECMO is needed to save these infants. However, a second course of ECMO may be beneficial in a select group of infants when recurrent persistent pulmonary hypertension develops. Other than abstract form, this is the first report of the use of a second course of ECMO in the literature. The authors report on three infants, two with recurrent persistent pulmonary hypertension secondary to congenital diaphragmatic hernia and one with necrotizing tracheobronchitis after Group B streptococcal sepsis who were treated at their institution with a second course of ECMO. Technical considerations in using a second course of ECMO depend upon the initial vessel cannulation site, time elapsed between cannulations, and the condition of the original artery and vein. By adopting a stenting procedure in those infants whose initial trial off was equivocal, a second cannulation may be prevented in neonatal patients with recurrent persistent pulmonary hypertension.

Bronchitis↗

PubMedDate not supplied

Use of extracorporeal life support in total anomalous pulmonary venous drainage.

OBJECTIVE: The objective of this study was to analyze the clinical course and neurodevelopmental outcome of infants with total anomalous pulmonary venous drainage (TAPVD) who were treated with venoarterial extracorporeal life support (ECLS). STUDY DESIGN: The study was done by retrospective national survey of ECLS centers located in the United States and Australia. Sixty-six patients from 28 centers that reported cases from 1976 to October 1992 to the Extracorporeal Life Support Organization registry were included in the study. Data regarding type of TAPVD, whether the diagnosis was known or suspected before the initiation of ECLS, method of diagnosis, timing of repair if done, outcome, and follow-up were collected. RESULTS: Fifty-six of the patients were placed on ECLS at ages < 14 days (neonatal) and 10 patients underwent ECLS at ages > or = 14 days (pediatric). TAPVD was known or suspected before the initiation of ECLS in 35 (53%) of 66 and was most commonly diagnosed by color-flow Doppler echocardiography if initially missed. Surgical repair was not attempted in four of the 66 patients, leaving a total of 62 patients for comparison. The overall operative survival for both neonatal and pediatric patients was 24 (39%) of 62. The survival rate for neonates who underwent repair before ECLS was seven (54%) of 13, for those who underwent repair after ECLS it was six (60%) of 10, and for those who underwent repair during ECLS survival was seven (24%) of 29. Neonatal survival (20/52, 38%) was statistically more likely (p = 0.05) if the repair was done before or after ECLS rather than during ECLS, with each group compared separately. Follow-up data were available on 13 of 20 neonates and three of four pediatric patients. Bayley Scales of Infant Development scores were normal in only six (54%) of 11 survivors who returned for testing. CONCLUSIONS: The diagnosis of TAPVD was often known before the initiation of ECLS. Neonates were more likely to survive if the repair could be done before or after ECLS rather than during ECLS. The lower survival of infants who underwent repair during ECLS reflects the degree of illness in many of these infants who were placed on ECLS on an emergency basis because their condition was too unstable to permit detailed cardiac evaluation. The survival rate of infants with TAPVD requiring ECLS is poor, with approximately one half of the survivors having mental and motor deficiencies; however, these infants represent a subset of patients with TAPVD who probably would have died without ECLS. We recommend that infants who are not starting to wean from ECLS at 7 days undergo reevaluation with color-flow Doppler echocardiography with consideration for cardiac catheterization if the diagnosis is in doubt. We also recommend that before infants with known TAPVD are placed on ECLS parents should be informed that survival with the use of ECLS is no different from survival with operation alone and that many of the survivors are impaired. Each active ECLS center should periodically review its accuracy in making this definitive diagnosis.

Extracorporeal Membrane Oxygenation↗

PubMedDate not supplied

Risk factors for intracranial hemorrhage in the extracorporeal membrane oxygenation patient.

The need for cardiopulmonary resuscitation and repeated correction of persistent acidosis identifies extracorporeal membrane oxygenation patients more likely to develop an intracranial hemorrhage. The objective of this study was to identify risk factors for an intracranial hemorrhage (ICH) in infants on extracorporeal membrane oxygenation (ECMO). This study was a retrospective-matched, case-controlled study of infants with ICH on ECMO compared with infants without ICH on ECMO. Data collected included patient demographics, ventilator parameters, blood gases, coagulation parameters, the need for cardiopulmonary resuscitation (CPR), neurologic findings, and outcome. The Neonatal Intensive Care Nursery at Kosair Children's Hospital in Louisville, Ky., was the setting. Twenty-three infants who developed an ICH (excluding subarachnoid hemorrhage) on ECMO were matched with a control group of 23 infants without an ICH on ECMO. The presence of acidosis (pH < 7.19 or HCO3 < 17; p < 0.01 and p < 0.05, respectively) and the need for CPR (heart rate < or = 80 or mean blood pressure < or = 30 mm Hg, p < 0.003) shortly before or during cannulation correlated with the development of an ICH in infants on ECMO. The infants with an ICH required more frequent platelet transfusions (p < 0.005), had difficulty maintaining activated clotting times (ACTs) within a normal range (p < 0.03), and had abnormal neurologic examinations shortly before or after the ICH was detected with head ultrasound. The ultrasound was obtained as soon as possible after a change in the neurologic status. The need for CPR and repeated correction of persistent acidosis before or during cannulation identifies ECMO patients more likely to develop an ICH. We found that elevated ACTs and low platelet counts requiring transfusion showed a statistical association with the development of an ICH. Daily head ultrasounds and frequent neurologic checks are thus valuable tools in assessing the ECMO patient who demonstrates difficulty in maintaining coagulation values in the normal range or who requires frequent platelet transfusions.

Blood Gas Analysis↗