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Biomedical subjects

P Lang

Publications and source records attributed to P Lang.

At least 343 records · Page 19Linked to original sources
PubMed1986

Electrocardiogram of the premature infant at 1 year of age.

ECGs were examined from 461 premature infants at 1 year of age. Data from those without a history of bronchopulmonary dysplasia were generally similar to published norms for healthy 1-year old infants. History and persistence of residual lung disease were reflected in the ECG by a high prevalence of findings suggestive of right ventricular hypertrophy. Clinically significant patent ductus arteriosus during the neonatal period did not influence the 1-year ECG findings. The data expand the published experience with follow-up ECGs from premature infants and suggest that the ECG may be a useful tool in follow-up of chronic residual lung disease in this population.

Bronchopulmonary Dysplasia↗
PubMed1985

Extravascular lung water in children immediately after operative closure of either isolated atrial septal defect or ventricular septal defect.

Extravascular lung water (EVLW) was measured in 16 patients with congenital heart disease by the cold green dye, double indicator dilution technique. Five patients with optimally corrected tetralogy of Fallot served as controls, and EVLW in this group was 4.7 +/- 0.5 ml/kg (111 +/- 13 ml/m2) (mean +/- standard deviation). In 5 asymptomatic patients with atrial septal defect (ASD), normal pulmonary artery (PA) pressure and increased pulmonary blood flow, EVLW was 5.7 +/- 2.8 ml/kg (132 +/- 63 ml/m2), which was not significantly different from the value of control patients. However, in 6 patients with ventricular septal defect, PA hypertension, normal left atrial pressure and an equivalent left-to-right shunt to ASD patients, EVLW was 15.9 +/- 3.8 ml/kg (270 +/- 60 ml/m2). This was significantly different from values in both control and ASD patients (p less than 0.01). It is concluded that in the face of normal pulmonary vascular resistance, PA pressure is transmitted to the microvasculature, causing hydrostatic pulmonary edema. Other factors that may be implicated in the pathogenesis of pulmonary edema, such as increased pulmonary blood flow and relative lymphatic insufficiency in infants, cannot be excluded.

Child↗
PubMed1985

Assessment of hemodynamic status in the intensive care unit immediately after closure of ventricular septal defect.

Hemodynamic values measured 12 to 24 hours postoperatively in the intensive care unit (ICU) were compared with those measured at a later cardiac catheterization in 68 patients after closure of ventricular septal defect (VSD). A pulmonary arterial (PA) saturation of more than 80% or a pulmonary to systemic blood flow ratio (Qp:Qs) greater than 1.5 in the ICU were sensitive indicators for identifying patients at risk of having a hemodynamically significant residual left-to-right shunt (Qp:Qs greater than 1.5) at catheterization. Measurement of PA pressure in the ICU was a useful predictor of PA pressure at catheterization. In the absence of factors known to alter PA pressure, measurement of PA pressure in the ICU overestimates what it will be at a subsequent cardiac catheterization. Early assessment of hemodynamics after closure of VSD is useful in identifying patients at risk of having hemodynamically significant residual VSD and those who may have persistent PA hypertension.

Adolescent↗
PubMed1985

Single ventricle (single- or double-inlet) complicated by subaortic stenosis: surgical options in infancy.

Intracardiac obstruction to the systemic circulation can develop in patients with many forms of congenital heart disease. When transposition of the great arteries accompanies tricuspid atresia, narrowing of the ventricular septal defect (VSD) leads to subaortic stenosis. In a similar fashion, a restrictive bulboventricular foramen compromises systemic arterial outflow in patients who have single left ventricle with subaortic outflow chamber. The same effect can be seen in VSD closure in mitral atresia with normally related great vessels. Although some forms of single ventricle can be treated by ventricular septation, the modified Fontan procedure can be more generally applied to this entity. Pulmonary vascular resistance must be low, however, which excludes the application of the Fontan principle in infants. While pulmonary artery banding may protect the lungs from the development of excessive pulmonary vascular resistance, it may also accelerate the development of subaortic obstruction. We have successfully applied the Norwood operation, as described for hypoplastic left heart syndrome, to palliate subaortic stenosis due to restrictive VSD in 3 infants with single ventricle or atrioventricular valve atresia. Consideration should be given to a primary Norwood procedure in infants with single ventricle in whom subaortic stenosis is likely to develop. Patients who do receive pulmonary artery bands should be followed closely for the development of subaortic stenosis and should undergo an early, physiologically corrective operation if it occurs.

Aortic Stenosis, Subvalvular↗
PubMed1985

Pulmonary and systemic hemodynamic responses to ketamine in infants with normal and elevated pulmonary vascular resistance.

Avoidance of ketamine has been recommended in children with pulmonary hypertension or with limited right ventricular reserve, despite absence of data about the effects of ketamine on pulmonary vascular resistance (PVR) in children. Ketamine has been associated with increased PVR in studies of adults; in these studies adults were spontaneously breathing through unprotected airways, despite ketamine's known effects of ventilatory depression and partial loss of airway. The authors measured pulmonary and systemic hemodynamic responses to ketamine during spontaneous ventilation in 14 intubated infants who were receiving minimal ventilatory support with an intermittent mandatory ventilation (IMV) of 4 at an FIO2 of 0.3-0.4. No significant changes were found in cardiac index (CI), pulmonary vascular resistance index (PVRI), or systemic vascular resistance index (SVRI) in a group of seven infants with normal PVRI or in another group of seven infants with preexisting increased PVRI. Results did not differ in infants receiving diazepam sedation. The authors conclude that ketamine has little effect on baseline hemodynamics in mildly sedated infants whose airway and ventilation are maintained; in particular, PVRI is little changed by ketamine administration in ventilated infants with either normal or increased baseline PVRI.

Blood Gas Analysis↗
PubMed1985

Failure of bone marrow cells to reconstitute T cell immunity in graft-vs-host mice.

A chronic GVH reaction (detected by T cell immune deficiency) was induced in unirradiated, adult (C57BL/10 X B10.A)F1 mice by injecting them i.v. with 3 X 10(7) B10.A parental spleen cells. Thirty-four days later, attempts were made to reconstitute the GVH immune-deficient mice by whole-body irradiation and repopulation with bone marrow cells from normal syngeneic F1 mice. The reconstituted mice were tested for CTL responses 147 and 272 days after repopulation with normal F1 bone marrow. These GVH/chimera mice remained immunoincompetent for at least 272 days for CTL responses to hapten-self and H-2 allogeneic antigens.

Animals↗
PubMed1985

Pulmonary and systemic hemodynamic responses to fentanyl in infants.

Pulmonary and systemic hemodynamic responses to fentanyl were studied in 12 infants after repair of congenital heart defects. During controlled ventilation, hemodynamic responses to 25 micrograms/kg of fentanyl were measured. No significant changes were found in heart rate, cardiac index, mean pulmonary artery pressure, or pulmonary vascular resistance index 5 min after the fentanyl had been given. There were small but statistically significant decreases in mean arterial pressure and systemic vascular resistance index after fentanyl. We conclude that under the conditions of this study, pulmonary and systemic hemodynamics in infants are minimally altered by 25 micrograms/kg of fentanyl.

Blood Pressure↗
PubMed1985

Blunting of stress responses in the pulmonary circulation of infants by fentanyl.

After repair of congenital heart defects, stress responses in the pulmonary circulation of fourteen infants produced by a brief endotracheal suctioning procedure were studied before and after fentanyl (25 micrograms/kg). The total time of disconnection from the ventilator with suctioning (FIO2 1.0) was limited to no more than 15 sec to avoid alveolar hypoxia. Before fentanyl, marked increases occurred in mean pulmonary artery pressure and pulmonary vascular resistance index with suctioning, whereas only mild increases in heart rate and mean systemic arterial pressure occurred. All of these increases with suctioning were almost completely abolished by 25 micrograms/kg fentanyl. We conclude that suctioning or other broncho-carinal stimulation can produce a marked pulmonary vasoconstrictive response in infants, which is blunted by fentanyl. This response is separate from that produced by hypoxic pulmonary vasoconstriction associated with prolonged clinical suctioning procedures or with loss of airway.

Blood Pressure↗
PubMed1984

Measurement of extravascular lung water in infants and children after cardiac surgery.

Extravascular lung water (EVLW) was measured in 17 patients with congenital heart disease by the cold-green-dye, double indicator-dilution technique. In 5 control patients, EVLW was 4.7 +/- 0.5 ml/kg (111 +/- 13 ml/m2) (mean +/- standard deviation). Twelve patients were studied immediately after correction of their heart defects. In 6 patients with normal or decreased pulmonary blood flow preoperatively (Group I), EVLW was 6.2 +/- 1.9 ml/kg (122 +/- 46 ml/m2). This value is not significantly different from that of the control patients. In 6 patients with increased pulmonary blood flow and congestive heart failure preoperatively (Group II), EVLW was 15.7 +/- 3.8 ml/kg (270 +/- 60 ml/m2), which is significantly different from both control and Group I patients (p less than 0.01). There was no correlation of EVLW with pre- or postoperative left atrial pressure, length of cardiopulmonary bypass or deep hypothermic circulatory arrest, postoperative serum protein, albumin, hematocrit or cardiac index. Thus, EVLW in the immediate postoperative period is determined by preoperative pathophysiologic characteristics rather than by intraoperative management, and patients with congestive heart failure resulting from left-to-right shunts have increased EVLW despite normal left atrial pressures.

Blood Pressure↗
PubMed1984

Transposition of the great arteries and intact ventricular septum: anatomical repair in the neonate.

Fourteen neonates 18 hours to 32 days old with transposition of the great arteries (TGA) and virtually intact ventricular septum (IVS) underwent arterial switch operations under deep hypothermic circulatory arrest. Preoperative left ventricular to right ventricular peak systolic pressure ratios ranged from 0.7 to 1.0 (mean, 0.92), and the echocardiogram showed a centrally positioned ventricular septum in 10 patients and a rightward displaced ventricular septum in 4. One patient died twelve hours after operation. Postoperative complications included bleeding from the left coronary artery-pulmonary artery anastomosis (1 patient), stenosis of the pulmonary artery-aorta anastomosis requiring reoperation (2 patients), transient ST segment and T wave abnormalities consistent with ischemia (3), and development of pathological Q waves suggestive of clinically silent infarction (2). The capacity of the left ventricle in a neonate to effectively take over the systemic circulation was clearly demonstrated. A longer follow-up period is needed to assess late ventricular function, coronary ostial growth, growth of the aorta-pulmonary artery anastomosis, late aortic valve (anatomical pulmonary valve) function before definitive recommendations about the superiority of the arterial switch operation in neonates with TGA plus IVS can be formulated.

Aorta↗
PubMed1984

Measurement of 24 hour whole body retention of 99Tcm-diphosphonate by a single thyroid probe.

In a comparative study with a thyroid probe and a whole body counter (WBC) we found that whole body retention (WBR) (2 h and 24 h) may be correctly obtained using a single probe, provided that measurements are taken carefully. With the detecting geometry presented, the single probe yielded only a slightly higher WBR than the WBC (less than 3 percentage points). We conclude that the method is capable of differentiating between pathological and normal WBR values.

Diphosphonates↗
PubMed1984

Surgical closure of patent ductus arteriosus in 268 preterm infants.

Over a 2 year period ending in April, 1981, 268 premature infants with birth weight below 1,750 gm underwent operation for a "hemodynamically significant" patent ductus arteriosus. Operations were performed in 13 centers participating in a collaborative study, which was primarily designed to evaluate the role of indomethacin in the management of patent ductus arteriosus. No patient died during the operations, which were done at a median age of 10 days. Eight infants (3%) died within 36 hours after operation. In only one was the death directly attributable to the operative procedure. Hospital mortality (23%) and postoperative morbidity, which included bronchopulmonary dysplasia, pneumothorax, and sepsis, were unrelated to birth weight, age at operation, and degree of preexisting pulmonary disease or preoperative treatment of the infant with indomethacin. Results indicate that surgical ligation is a safe and effective procedure for treating patent ductus arteriosus with large left-to-right shunting in small premature infants.

Clinical Trials as Topic↗
PubMed1984

Hemodynamic response to high-frequency ventilation in infants following cardiac surgery.

The hemodynamic response to high-frequency ventilation was compared with conventional ventilation in six infants following cardiac surgery. While undergoing high-frequency ventilation, adequate gas exchange was maintained in all infants. High frequency ventilation allowed a reduction of peak ventilatory pressure at the airway opening by 19%, and peak tracheal pressure by 42%. No clinically important changes in heart rate, systemic and pulmonary arterial pressure, cardiac index, or systemic and pulmonary vascular resistance were noted when high-frequency ventilation was compared with conventional ventilation.

Blood Pressure↗