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Biomedical subjects

C J Stolar

Publications and source records attributed to C J Stolar.

At least 37 records · Page 2Linked to original sources
PubMed1995

Cholelithiasis in pediatric cardiac transplant patients on cyclosporine.

From June 1984 to June 1993, symptomatic chlolethiasis was observed in six (6.7%) of 90 cases of pediatric heart or heart-lung transplants at the author's institution. The incidence of cholelithiasis for all children under 16 years of age is estimated to be less than 1%. Previously, information on cholelithiasis in pediatric transplant patients on cyclosporine therapy had been limited. Studies concerning the incidence of gallstones in adult kidney and cardiac transplant patients have shown that there is an increase associated with cyclosporine, possibly related to elevated levels and hepatoxicity. Five patients underwent uneventful cholecystectomy. There was only one death, which occurred after emergency cholecysostomy tube placement for biliary sepsis. If indicated, biliary tract surgery can be performed safely in cardiac transplant patients. The authors report on their experience with symptomatic cholelithiasis in pediatric cardiac transplant patients and review the current literature on the hepatotoxic effects of cyclosporine.

Adolescent↗
PubMed1994

Fetal breathing characteristics and postnatal outcome in cases of congenital diaphragmatic hernia.

OBJECTIVE: Our purpose was to determine characteristics of fetal breathing activity by recording fetal nasal fluid flow velocity in cases of congenital diaphragmatic hernia. STUDY DESIGN: Fetal breathing-related nasal fluid flow was studied in 47 patients at 34 to 41 weeks of gestation, 16 cases of antenatally diagnosed congenital diaphragmatic hernia and 31 cases of uncomplicated pregnancy. The examination was performed by ultrasonography combined with color-flow and spectral Doppler analysis. An average of 25 breath cycles from each case was determined for each of the following timing parameters: breath-to-breath interval, time of inspiration, time of expiration, and ratio of time of inspiration and time of expiration. RESULTS: In all cases with uncomplicated pregnancy fetal breathing-related nasal fluid flow was seen at the level of the nose, and the timing components of this flow were determined as control values. In two cases with diaphragmatic hernia no perinasal flow was demonstrated, although fetal breathing movements observed as chest wall movements were present. The other 14 cases with congenital diaphragmatic hernia who demonstrated perinasal flow had the following postnatal outcome: one stillbirth, five neonatal deaths (group I), and eight survived and were discharged (group II). The study revealed that the time of expiration (in milliseconds) in group II (493.2 +/- 34.3 SEM) was significantly (p = 0.0030) shorter than in group I (653.4 +/- 38.4) and in cases of uncomplicated pregnancy (633.6 +/- 18.5). The value of the time of inspiration/time of expiration ratio in group II was approximately 15% higher than in group I and approximately 30% higher than in cases of uncomplicated pregnancies. CONCLUSIONS: Observation of fetal breathing-related nasal fluid flow velocity in cases of antenatally diagnosed congenital diaphragmatic hernia provides a rationale for the hypothesis that time of expiration and the time of inspiration/time of expiration ratio may be useful in the prediction of postnatal outcome. We speculate that the changes in the group of survivors may represent a compensatory phenomenon by causing intermittent changes in the volume of fluid within the lungs.

Amniotic Fluid↗
PubMed1994

Neuroimaging of brain injury in neonates treated with extracorporeal membrane oxygenation: lessons learned from serial examinations.

The head ultrasound (US) is used extensively at most extracorporeal membrane oxygenation (ECMO) centers to screen for intracranial pathology in the ECMO candidate. Daily head US examinations are obtained in patients on ECMO to detect the emergence of intracranial hemorrhage (ICH). The authors asked whether these serial studies could be correlated with more definitive diagnostic studies, such as computed tomography (CT) and magnetic resonance imaging (MRI) scans, autopsy data, or the long-term neurodevelopmental status, to discern the predictive value of these daily examinations. Seventy-four consecutively treated neonates with reversible respiratory failure refractory to conventional support met institutional criteria for placement on ECMO. In addition to a pre-ECMO US, daily real-time portable head US images were evaluated for changes in echotexture, ventricular configuration, and extraaxial fluid. Follow-up CT and MRI scans were evaluated for the presence of hemorrhagic or ischemic lesions. Autopsy data were obtained from nonsurvivors. Survivors were examined by a neurodevelopmental specialist at regular intervals and classified as normal or delayed for chronological age. In this series of 74 patients, CT/MRI scanning and autopsy data demonstrated structural injury in 19 patients; there were 16 ischemic infarctions and three hemorrhages. The incidence of hemorrhage in this series was considerably lower than that previously reported. Ten of the 19 patients had serial head US findings demonstrating a progression from focal increases in echotexture to diffuse effacement of cerebral architecture. In the remaining nine, serial head US examinations did not show injury. An additional 10 children had a clear delay in neurological development despite no evidence of anatomic injury on serial head US examinations or CT/MRI scanning.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗
PubMed1994

Differential effects of inhaled nitric oxide on normoxic and hypoxic isolated in situ neonatal pig lungs perfused by extracorporeal membrane oxygenation.

Inhaled nitric oxide (NO) is effective as a selective pulmonary vasodilator, but its effects on uninjured lungs subjected to normoxia and hypoxia have not been fully studied. The authors sought the response of pulmonary vascular resistance (PVR) to inhaled NO in piglet lungs devoid of ischemic injury in a model of reversible pulmonary hypertension. If the changes were dose-responsive, the authors asked whether the PVR changes were related to normoxia or hypoxia, and hypothesized that the change would be more pronounced for hypoxia than normoxia. In situ isolated piglet lungs were prepared by occlusive tracheostomy and ligation of the ductus arteriosus and aorta. Cannulae positioned in the left atrium and pulmonary artery were connected to a standard extracorporeal membrane oxygenation (ECMO) circuit, and flow was increased to approximate cardiac output. After stabilization, piglets (aged 5 to 14 days, weighing 3.2 to 6.4 kg) were divided into two groups of four each: normoxic (FIO2 0.30, normal PVR) and hypoxic (FIO2 0.07, increased PVR). NO was administered at 10 to 80 parts per million (ppm) in increments of 10 ppm, for 5 minutes at each concentration, with a return to baseline before each new dose. Flow, pulmonary arterial (PA) and left atrial (LA) pressures were continuously monitored, from which PVR was calculated (PVR = [PPA - PLA]/flow) and expressed as log delta PVR. Data were analyzed statistically by repeated measures of analysis of variance, comparing log delta PVR to baseline at each dose of NO, and comparing log delta PVR for normoxic and hypoxic lungs at each dose of NO.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Fetal upper respiratory tract function in cases of antenatally diagnosed congenital diaphragmatic hernia: preliminary observations.

Fetal upper respiratory tract function was studied in five cases of antenatally diagnosed congenital diaphragmatic hernia and in 16 cases of uncomplicated pregnancy at gestational ages ranging from 27 to 38 weeks. The evaluation of fetal upper respiratory tract function was performed using ultrasonography combined with color-flow and spectral Doppler analysis. In all cases with uncomplicated pregnancy, fetal breathing-related nasal and oropharyngeal fluid flow was seen at the level of the nose. The five cases with congenital diaphragmatic hernia all demonstrated fetal breathing activity by thoracic wall movement. In four of the fetuses, perinasal fluid flow was seen by the Doppler technique. The fetus with no demonstrated perinasal flow during breathing movements died in the early neonatal period and had pulmonary hypoplasia. Observation of the fetal breathing-related nasal and oropharyngeal fluid flow in cases of antenatally diagnosed congenital diaphragmatic hernia provides a rationale to hypothesize that the absence of this phenomenon is a useful marker for prenatal prediction of pulmonary hypoplasia.

Journal Article↗
PubMed1993

Altered diaphragm function modifies neonatal lung growth: biologic morphometric assessment.

Thoracic volume relationships supported by the diaphragm are important mechanical components of neonatal lung growth. Alterations modify regional lung growth. We used stereologic morphometry to study effects of altered diaphragm function on alveolar growth in neonatal pigs. Nine piglets (1 mo) were divided into three groups: unilateral phrenectomy, noncompliant patch replacement of diaphragm, and sham. Seven days later lungs were fixed in situ with 2.5% glutaraldehyde by airway installation at 20 cm H2O. Five 1-mm cubes were cut from lung corresponding to apex/RUQ(A), base/RLQ(B), apex/LUQ(C), and base/LLQ(D) and prepared for light microscopy (n = 25/quad/animal). Stereologic morphometry involved point counting for air volume density and point intersect to determine the surface area density of the alveolar spaces. Results were analyzed for variance and by Tukey range testing. Variance of air volume % between groups-quadrants B, C, D had decreased air volume % in phrenectomy group compared with patch and sham group (P < .05). Variance of air volume % within groups, for phrenectomy group A (81.5%), is different from all others (B = 70.6%, C = 75.5%, D = 66.7%); C is different from D (P < .05). For patch and sham group, D (P = 74.8%, S = 80.7%) is different from A (P = 84.1%, S = 86.6%) and C (P = 86.2%, S = 84.4%). Variance of surface area density between groups--quadrant D had increased surface area density % in phrenectomy group compared to sham group (P < .05). Variance of surface area density % within groups, for phrenectomy group, A (37.9 mm-1) is different from D (55.7 mm-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1993

Extracorporeal membrane oxygenation: support for overwhelming pulmonary failure in the pediatric population. Collective experience from the extracorporeal life support organization.

Data from the Extracorporeal Life Support Organization (ELSO) regarding the use of extracorporeal membrane oxygenation (ECMO) in pediatric patients with respiratory failure are reviewed. Two hundred eighty-five children between the ages of 14 days and 18 years were supported with ECMO between January 1982 and September 1991. Although these data represent the experience of 52 ECMO centers, seven centers accounted for over 50% of the total. The patients had a mean age of 33 +/- 48 months with a median age of 13 months: 137 (48%) were male and 148 (52%) were female. There were numerous primary pulmonary diagnoses: the two most common were presumed viral pneumonia (32%) and adult respiratory distress syndrome (28%). Entry criteria for ECMO, although poorly defined and specific to each institution, attempted to identify children with an 85% to 100% predicted mortality. The survival rate with ECMO was 47% (135/285). Pre-ECMO mechanical ventilatory support was extreme with an FIO2 .97 +/- .07 and a mean airway pressure (MAP) 23.6 +/- 8 cm H2O used to achieve PaO2 of 50 +/- 39 and PaCO2 51 +/- 22 mm Hg. The MAP was significantly higher in nonsurvivors versus survivors (25.3 +/- 8.7 v 22.0 +/- 7.1 cm H2O, P < .01). The duration of ECMO was 4 hours to 35.5 days with a mean of 245 +/- 165 hours, which is approximately 10 days. Duration for survivors was 222 +/- 151 hours compared with 266 +/- 176 hours for nonsurvivors. ECMO complications are divided into two categories: mechanical (directly related to the ECMO circuit) and medical (patient related).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Newborn surgical emergencies. Congenital diaphragmatic hernia and extracorporeal membrane oxygenation.

Bochdalek hernia is a posterolateral defect in the embryogenesis of the diaphragm. Abdominal contents enter the thorax during fetal development and result in pulmonary hypoplasia. A cause of respiratory distress in the newborn, the management of this disease has undergone dramatic changes. The defect requires surgical repair, but success depends more on preoperative and postoperative management of the associated physiologic derangements.

Animals↗
PubMed1992

The CCSG prospective study of venous access devices: an analysis of insertions and causes for removal.

This is an interval analysis of the 2-year prospective multicenter Childrens Cancer Study Group study of 1,141 chronic venous access devices in 1,019 children with cancer. Device type was external catheter (EC) 72%, totally implantable (TID) 28%, and did not differ for diagnosis or age except more double-lumen devices in bone marrow transplant protocols (77%) and more TIDs in children less than 1 year old (17.7%). Insertion characteristics evaluated in 1,078 (95%) were: operating room placement 99%; general anesthesia 98%; cutdown 67%; percutaneous 33%; atrial position 50%, caval position 50%; and perioperative antibiotics 48%. Vein entry was the external jugular 33%, internal jugular 22%, subclavian 35%, cephalic 7%, and saphenous 3%. Insertion was difficult or very difficult in only 10% and operative complications occurred in only 0.7%. Degree of difficulty bore no relationship to device type or patient age. The reasons for removal in 736 devices (67%) were due to complications in 39%, of which infections were the most frequent. There was some variance between centers ranging from 8.5% to 31% for infection; 2.8% to 24% for dislodgment; and 0% to 13% for occlusion. ECs had a higher risk of dislodgment; elective removals were more frequent in TIDs; there was no difference in infection as a cause for removal between ECs and TIDs. Dislodgment was associated with the shortest distance of the cuff to the skin exit (mean, 4 cm): less than or equal to 2 cm, 49%; greater than 2 cm, 28% (P = .009) and occurred most frequently in the younger patient (18.9%, 0 to 1 years; 0.5%, greater than 8 years.

Adolescent↗
PubMed1992

The role of surgery in abdominal non-Hodgkin's lymphoma: experience from the Childrens Cancer Study Group.

To determine the appropriate role of surgical intervention in non-Hodgkin's lymphoma primary to the abdomen, we analyzed the effect of multiple prognostic determinants on event-free survival for patients entered into the CCG-551 study. Eighty-four patients were identified with abdominal lymphoma and of these adequate data for analysis was available on 68 (81%). Variables of interest included: extent of disease at diagnosis, completeness of resection, use of bowel resection, radiation to the primary site, and sex/age/race. The median age on study was 8 years; 79% of patients were white and 85% were male. Thirty-three patients (49%) presented with localized disease. Laparotomy was performed in 67 children (99%) with complete gross resection in 28 (42%). Of the 10 reported surgical complications, 8 occurred in those with extensive disease who were incompletely resected. Radiation to the primary site was given in 60% of patients with median dose of 2,000 cGy. Analysis was performed both for the overall group and for the subgroup receiving optimal chemotherapy for histopathology. Variables with significant predictive effect on event-free survival in univariate analysis included extent of disease (P less than or equal to .001), complete resection (P less than or equal to .002), and use of bowel resection (P less than or equal to .004). However, in multivariate analysis, only extent of disease was an independent predictor of outcome. The data support a role for complete operative excision of localized lymphomas especially when accomplished with bowel resection. Aggressive attempts at debulking extensive retroperitoneal or mesenteric lymphomas are contraindicated.

Abdominal Neoplasms↗
PubMed1992

Mechanical forces contribute to neonatal lung growth: the influence of altered diaphragm function in piglets.

Neonatal lung growth is controlled in part by mechanical forces. Altered mechanical forces precipitated by phrenectomy or prosthetic replacement of the diaphragm result in altered thoracic volume relationships, which, in turn, change lung distending pressures and or thoracic volume. These effects might contribute to regional lung growth. We postulated a relationship between altered thoracic mechanical forces and changes in lung growth and asked if altered diaphragm function influenced regional lung growth. Piglets (28d, 7-8kg), were assigned to left transthoracic phrenectomy (P), prosthetic diaphragm replacement (PDR), or sham (S), (n = 6). After a mean 10 days, piglets were studied with tracheostomy and regional pleural pressure transducers. Integrated lung volumes (LV) were recorded with intrapleural pressure (Pip). Dynamic compliance (Cdyn) was calculated (dV/dP). After sacrifice continuous pressure volume (P/V) curves were generated. Lungs were then cut into 4 quadrants based on relationship to R/L bronchus and processed for DNA content and total protein indexes. Analysis of data were made within and between groups. Body weight and gain were similar in all. LV, Pip, Cdyn, and P/V were not significantly different in PDR and P compared with S. Pip differences between thoracic regions within each group were significant for PDR and showed LU less than RU, LL less than RL (P less than 0.05). RU and RL Pip in the PDR group were the same as S. Pip in the P group were decreased in the RU, LU, and LL but only the LL approached significance. Whole lung wet weights were decreased (P less than .05) in P compared to PDR and S.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Differential effects of alveolar and arterial oxygen tension on pulmonary vasomotor tone in ECMO-perfused, isolated piglet lungs.

Hypoxia is a known stimulant of pulmonary hypertension. We hypothesized graded effects of alveolar (PAO2) and arterial (PaO2) oxygen tension on pulmonary vascular resistance (PVR). A standard in situ, isolated lung preparation was modified by adding an oxygenator to the perfusion circuit with cannulation of the unarrested heart, allowing control of PAO2 and PaO2 in lungs devoid of ischemic injury. Seven anesthetized piglets were prepared with occlusive tracheostomy, ductus arteriosus ligation, and cannulation of the left atrium and main pulmonary artery. Animals were exsanguinated while simultaneously perfusing the lungs with a donor-blood primed extracorporeal membrane oxygenation circuit. Flow, left atrial pressure, pH, and PCO2 were kept constant. PAO2 and PaO2 were altered to establish four different experimental conditions as described by a latin square. PVR was calculated from measurements of pulmonary artery pressure (PAP) before and after introducing an experimental condition. Results show that (1) alveolar hypoxia significantly increases PVR despite arterial hyperoxia; (2) alveolar hypoxia is a more potent stimulus of pulmonary vasoconstriction than arterial hypoxemia; (3) alveolar and arterial oxygen tension are independent, additive effectors of PVR; and (4) recovery from acute hypoxic pulmonary vasoconstriction may be more sensitive to alveolar oxygen tension.

Animals↗
PubMed1991

Congenital diaphragmatic hernia, extracorporeal membrane oxygenation, and death: a spectrum of etiologies.

Extracorporeal Life Support Organization (ELSO) registry data show increased mortality in congenital diaphragmatic hernia (CDH) infants compared with other extracorporeal membrane oxygenation (ECMO) indications. To test the hypothesis that death might be related to various clinical parameters, retrospective data collection was solicited on 175 ECMO-related CDH deaths from 41 American ECMO centers (ELSO Registry 1980 through 1989). Data capture forms were received on 100 of 175 infants representing 29 of 41 centers. After review of all available material, a predominant cause of death was assigned. Other diagnoses were given secondary status. We analyzed arterial blood gas values at 6, 3, and 1 hour pre-ECMO, as well as at the time of highest recorded PO2 (preductal and postductal) and lowest recorded PCO2, and correlated these findings with predominant cause of death. The relationship between individual variables and cause of death was assessed by t test. Multivariate analysis was performed by using a stepwise discriminate procedure. The most common predominant causes of death were brain death (29%), pulmonary hypertension (25%), and pulmonary hypoplasia (17%). Correlation of arterial blood gas values at 6, 3, and 1 hour pre-ECMO with predominant causes of death established the following statistically significant associations (P less than .05): (1) pulmonary hypoplasia and low PO2 at 6 hours pre-ECMO; (2) brain death and low pH at 1 hour pre-ECMO; and (3) pulmonary hypertension and high HCO3- at 1 hour pre-ECMO.(ABSTRACT TRUNCATED AT 250 WORDS)

Bicarbonates↗
PubMed1991

Extracorporeal membrane oxygenation and neonatal respiratory failure: experience from the extracorporeal life support organization.

Extracorporeal membrane oxygenation (ECMO) has rescued moribund infants with respiratory failure from a variety of causes. We report the experience from 58 United States and 7 overseas ECMO centers between 1980 and 1989. Voluntarily submitted data forms provided details of diagnosis, clinical condition, ECMO indications, morbidity, and mortality. Of 3,528 infants with a predicted mortality greater than 80% treated with ECMO, 83% survived. Entry diagnoses and aggregate survival were: meconium aspiration syndrome (MAS) 1,356 (93%), persistent pulmonary hypertension of the newborn (PPHN) 480 (83%); congenital diaphragmatic hernia (CDH) 585 (62%); hyaline membrane disease (HMD) 532 (84%); sepsis 416 (77%); and other 185 (77%). ECMO indications were a-AdO2 greater than 600 for 6 to 8 hours (22%), oxygenation index greater than 40 for 4 hours (18%), acute deterioration (14%), maximal therapy failure (34%), and barotrauma (1%). Annual survival improved over 9 years except for CDH, which decreased from 70% (1987) to 56% (1989) P less than .01). Survivors differed from non-survivors (P less than .05) by birth weight (greater than 2 kg), gestational age (greater than 37 weeks), entry diagnosis (MAS, PPHN, HMD, sepsis v CDH), inborn versus outborn, pre-ECMO pH, and ECMO duration. Technical complications in 25% of patients and medical complications in 75% adversely affected survival. Annual sepsis survival improved to 75% (1989) but had significantly greater complication rates (P less than .05) than other diagnoses. Multicenter data yield information not available from single institution experience. Although entry criteria and conventional therapy continue to evolve, ECMO currently improves survival from an estimated 20% to 83% overall. Individual prognosis depends on entry diagnosis, clinical condition, and complications.

Equipment Failure↗
PubMed1991

Extracorporeal membrane oxygenation for perioperative support in pediatric heart transplantation.

Extracorporeal membrane oxygenation has demonstrated effectiveness for cardiopulmonary support in a variety of clinical situations. This article reviews the cases in which extracorporeal membrane oxygenation was used as an adjunct to pediatric cardiac transplantation. Twenty children, aged 7 days to 17 years, with cardiac failure refractory to conventional therapy received extracorporeal membrane oxygenation for 6 to 192 hours. In 4 cases it was used as a bridge to transplantation; in 10 cases it facilitated resuscitation of the cardiac allograft in the immediate postoperative period; and in 6 cases it complemented therapy for severe rejection in the late postoperative period. Twelve patients survived extracorporeal membrane oxygenation, 7 of whom lived more than 8 months. One long-term survivor was in the bridge-to-transplant group, 4 in the immediate postoperative group, and 2 in the rejection group. All survivors have normal cardiac allograft function. These data suggest that extracorporeal membrane oxygenation can be used to support profound cardiac failure in the pediatric heart transplant patient as a bridge to transplantation, in the resuscitation of the cardiac allograft, or to supplement a rejecting allograft.

Adolescent↗
PubMed1990

Anatomic and functional abnormalities of the esophagus in infants surviving congenital diaphragmatic hernia.

As more infants with congenital diaphragmatic hernia (CDH) survive by means of extracorporeal membrane oxygenation (ECMO), new clinical observations are being made. We report anatomic and functional abnormalities of the esophagus in these infants. Twenty-two of 30 infants with CDH survived. Three of 7 non-ECMO-treated infants and 14 of 17 ECMO-treated infants had an air- or fluid-filled mediastinal mass that was confirmed by an upper gastrointestinal series as ectatic esophagus. Contrast studies demonstrated severe gastroesophageal reflux. Intra-esophageal pH monitoring confirmed significant reflux (Euler scores greater than 50) in 69% of tested patients. Prolonged acid clearance in most patients implied abnormal peristalsis. Hydramnios was correlated to the observed esophageal abnormalities, being present in 13 of 16 infants with an available amniotic history. All patients had symptomatic gastroesophageal reflux managed without antireflux surgery and were discharged 36 +/- 2 days after initiation of feeding. Follow-up (range: 7 to 56 months; mean: 32 months) showed that weight gain in affected children was slower than in those not affected. All but one are asymptomatic. Repeat upper gastrointestinal series shows persistent ectasia but less gastro-esophageal reflux. Gastroesophageal reflux/ectasia is a new observation with CDH. The associated hydramnios may result from proximal foregut obstruction by kinking the gastroesophageal junction with CDH. The radiographic appearance can be quite unusual. Clinical manifestations of gastro-esophageal reflux are manageable without surgery but may account for the observed compromised growth.

Dilatation, Pathologic↗
PubMed1990

Modification of cardiopulmonary hemodynamics and vasoactive mediators by extracorporeal membrane oxygenation in newborn lambs.

We asked if prolonged venoarterial extracorporeal membrane oxygenation (ECMO) causes alterations in cardiopulmonary hemodynamics that might be reflected in arbiters of vascular tone: thromboxane, prostacylin, norepinephrine, and epinephrine. Newborn lambs undergoing ECMO demonstrated significant augmentation of systemic and pulmonary arterial blood pressure that was temporally related to rises in all vasoactive mediators measured. Although the prostanoids returned to baseline within 30 minutes, the catecholamines remained elevated significantly throughout bypass. Long-term bypass, however, was not associated with sustained systemic hypertension. Pulmonary hypertension was achieved only after 6 hours of bypass. These acute and chronic changes may exacerbate a pathological state for which ECMO is indicated.

Animals↗