Gastric-outlet obstruction induced by prostaglandin therapy in neonates

BACKGROUND

An infusion of prostaglandin E1 is widely used to maintain patency of the ductus arteriosus in neonates with congenital heart disease. After gastric-outlet obstruction was recognized in several infants who received prostaglandin E1, we studied the association between the drug and this complication.

METHODS

We evaluated all neonates who received prostaglandin E1 in our hospital between October 1, 1989, and September 30, 1991, for clinical, radiologic, or pathological evidence of acute gastric-outlet obstruction.

RESULTS

Of the 74 neonates evaluated, 65 had no signs of gastric obstruction and were considered normal; 5 had clinical and radiologic or pathological evidence of gastric obstruction consistent with the presence of antral mucosal hyperplasia. The remaining four neonates had clinical signs of gastric obstruction, but no radiologic or pathological examinations were performed. The 5 neonates with antral hyperplasia had received prostaglandin E1 for longer periods (mean [+/- SD] duration, 569 +/- 341 hours) than the 65 normal neonates (54 +/- 58 hours, P less than 0.001) or the 4 neonates with clinical signs of gastric obstruction (119 +/- 60 hours, P less than 0.05). The cumulative dose of prostaglandin E1 was higher in the neonates with antral hyperplasia (2982 +/- 1392 micrograms per kilogram of body weight) than in the normal neonates (279 +/- 270 micrograms per kilogram, P less than 0.001) or the neonates with signs of gastric obstruction (528 +/- 306 micrograms per kilogram, P less than 0.01). In two neonates with antral hyperplasia, the cessation of therapy lessened the gastric-outlet obstruction.

CONCLUSIONS

The administration of prostaglandin E1 to neonates can cause gastric-outlet obstruction due to antral hyperplasia. Neonates who receive prostaglandin E1 at recommended doses for more than 120 hours should be closely monitored for evidence of antral hyperplasia.

Corneal diameter, axial length, and intraocular pressure in premature infants

PURPOSE

Seventy premature infants 25 to 37 weeks' postconceptional age were examined during their first week of life to determine the correlation of corneal diameter, axial length, and intraocular pressure with gestational age and birth weight.

METHODS

Corneal diameter measurement was determined with corneal templates, total axial length with standardized A-scan ultrasound, and intraocular pressure with a Tonopen II tonometer.

RESULTS

Corneal diameter and total axial length showed parallel linear increases from 6.2 mm to 9.0 mm and 12.6 mm to 16.2 mm, respectively; however, no significant correlation was found between intraocular pressure and gestational age or birth weight. The mean intraocular pressure was 10.3 mmHg (standard deviation, 3.5).

CONCLUSION

Normative values are established for corneal diameter and total axial length as they relate to birth weight and gestational age, and a mean and standard deviation for intraocular pressure in the premature newborn. These values will aid the ophthalmologist in assessing ocular dimensions in premature infants.

Induction of labor as compared with serial antenatal monitoring in post-term pregnancy. A randomized controlled trial. The Canadian Multicenter Post-term Pregnancy Trial Group

BACKGROUND

The rates of perinatal mortality and neonatal morbidity are higher for post-term pregnancies than for term pregnancies. It is not known, however, whether the induction of labor results in better outcomes than does serial fetal monitoring while awaiting spontaneous labor.

METHODS

We studied 3407 women with uncomplicated pregnancies of 41 or more weeks' duration. The women were randomly assigned to undergo induction of labor or to have serial antenatal monitoring and spontaneous labor unless there was evidence of fetal or maternal compromise, in which case labor was induced or cesarean section was performed. In the induction group, labor was induced by the intracervical application of prostaglandin E2. Serial antenatal monitoring consisted of counts of fetal kicks, nonstress tests, and assessments of amniotic-fluid volume. The outcomes we measured were the rates of perinatal mortality, neonatal morbidity, and delivery by cesarean section.

RESULTS

Among the 1701 women in the induction group, 360 (21.2 percent) underwent cesarean section, as compared with 418 (24.5 percent) of the 1706 women in the monitoring group (P = 0.03). This difference resulted from a lower rate of cesarean section performed because of fetal distress among the women in the induction group (5.7 percent vs. 8.3 percent, P = 0.003). When two infants with lethal congenital anomalies were excluded, there were no perinatal deaths in the induction group and two stillbirths in the monitoring group (P not significant). The frequency of neonatal morbidity was similar in the two groups.

CONCLUSIONS

In post-term pregnancy, the induction of labor results in a lower rate of cesarean section than serial antenatal monitoring; the rates of perinatal mortality and neonatal morbidity are similar with the two approaches to management.

[Abilities and requirements profile of rheumatic patients, basis for suitability assessment as an interdisciplinary task in vocational rehabilitation]

Vocational rehabilitation service provision is always required when current job tasks can no longer be carried out due to disease-related performance restrictions. For social service agencies and employment offices as well as the rehabilitation facilities to intervene, information is needed on the remaining abilities, in order to be able to match future job requirements accordingly. Chronic rheumatic diseases gain increasing importance due to their high incidence and chronic progression; their impact on the capacity for work is considerable, with little attention however so far paid by the rehabilitation community. For 30 rheumatic patients of working age, abilities profiles have therefore been prepared and requirements profiles been established for their current job tasks, based on the methodological concept of Ertomis-Stiftung which had been supplemented by certain items important from an industrial medical angle. The findings show that the rheumatic person experiences limitations in all movement functions, and that lifting and carrying in particular are not possible. A major request is inclusion of a dynamic assessment criterion in the abilities profiles, as the person with a rheumatic disease in principle is capable of carrying out all movements, not however at the speed required to perform the job tasks.

[The occurrence of tumors in large bears (Ursidae)--a literature review and six case descriptions]

Histological findings on two Malayan sun bears and four sloth bears show that malignant neoplasms play an important role in tropic bears. Further, most of the tumors originated from the hepatic and biliary tract. Our results were compared with other investigations on zoo animals during the last 70 years revealing that malignant neoplasms are the most common ones in bears of the family Ursidae. Accordingly to our results, sloth and Malayan sun bears seem to have a disposition to develop malignant neoplasms of the hepatic and biliary tract, but within other species only polar bears seem to suffer predominantly from such neoplasia. The reason for this phenomenon could be an alimentary intake of carcinogens. Furthermore, Malayan sun bears show very often neoplasms of the thyroid gland as it is also observed in other carnivora.

Hyperplasia of somatostatin and pancreatic polypeptide immunoreactive cells in dogs with idiopathic atrophy of the exocrine pancreas

The pancreatic tissue from 25 dogs with idiopathic atrophy of the exocrine pancreas, and from 6 control dogs, was studied histologically and immunohistometrically. Cells producing insulin (B), glucagon (A), somatostatin (D), and pancreatic polypeptide (PP) were identified using specific antisera and the ABC technique. Histometrical quantitation revealed differences in the distribution of these cell types between the right and left pancreatic lobe. Initial stages of atrophy showed little changes concerning the relative proportions of the four cell types examined. In more advanced stages of atrophy, however, there was significant increase in the percentage of the D cells in the cell population of the left lobe. B and A cells showed no significant changes. In final stages, only tiny tissue spots were considered a secondary and regenerative phenomenon, but an endocrine dysregulation cannot be excluded. Atrophy accompanied by diabetes mellitus and a lack of B cells seem to be due to a deficiency of insulin.

Cerebral blood-flow velocity patterns in post-hemorrhagic ventricular dilation

To evaluate the effect of ventricular dilation (VD) on cerebral hemodynamics, serial cerebral bloodflow velocity patterns from the anterior and middle cerebral, and circle of Willis arteries were examined by range-gated, pulsed Doppler sonography in premature infants developing post-hemorrhagic VD. Nine infants (25 to 30 weeks gestation) without a patent ductus arteriosus were studied until resolution of VD. Forty-nine cranial sonograms from all nine infants were reviewed independently and grouped cross-sectionally into mild, moderate and severe VD prior to shunt. The corresponding pulsatility index (PI) showed a consistent trend of increase with VD in all three studied vessels. In six infants, absent or reversed diastolic flow was observed at the height of VD. Four of these infants required V-P shunt. Immediate fall in PI occurred in all three vessels. Serial measurement of PI during VD reflects global changes in cerebrovascular resistance. Results confirmed PI could be a useful index in monitoring cerebral hemodynamic changes.

Regional cerebral blood flow velocity patterns in newborn infants

Using range-gated pulsed Doppler sonography, cerebral blood flow velocity (CBFV) waveforms from the anterior cerebral artery (ACA), middle cerebral artery (MCA) and circle of Willis artery (CW) were examined in a total of 34 newborn infants. We compared the pulsatility index (PI) from the three cerebral arteries sampled in 10 term and 10 preterm (29 +/- 2 weeks) newborn infants without a history of perinatal asphyxia or intracranial pathology. The Pl in the ACA ranged from 0.60 to 1.03. There were no significant differences in Pl between the three vessels by paired comparisons. The Pl of the MCA differed from that of the ACA by 0.00 +/- 0.05. The variation coefficient (CV) was 7%. For CW with ACA, the difference was 0.00 +/- 0.04 and CV was 6%. Both intra- and interexaminer variation in Pl measurements were studied in another 14 infants. The variation coefficients were 5-8% for all three cerebral arteries. We showed that CBFV waveform patterns were similar in regional cerebral arteries, with Pl being a consistent CBFV index. In normal cerebral circulation, the intervessel Pl differences were within observer variations. Deviation from this may suggest abnormal regional cerebral haemodynamics.

Impact of delayed development in premature infants on mother-infant interaction: a prospective investigation

We examined events that precede a diagnosis of developmental delay by comparing 16 very low birth weight premature infants whose condition was diagnosed as developmental delay at 18 months corrected age with 16 matched developmentally normal infants. All infants were observed with their mothers during maternal visits to the nursery and during home visits 1, 3, 6, and 9 months after discharge. The mothers' reactions to their infants were rated at these times. All the children were followed up at a neonatal clinic, and detailed clinic records were used to document the time when a physician first suspected a delay and when this delay was first mentioned to the mother. The results indicate that parents had usually been told of their child's handicap by the time the child was 6 to 9 months old; yet mothers of the delayed children changed the interaction with their children as early as 1 month after discharge from hospital. These mothers initially touched, smiled at, and talked to their developmentally delayed infants significantly more often, but by 9 months they did so much less often than mothers of nondelayed children. The degree of change in mothers' behavior was related to their psychosocial background, with better-adjusted mothers showing the most change. We conclude that mothers' statements about their infants are usually valid and that physicians may share their potential concerns about infants more freely.

Effect of pneumothorax-induced systemic blood pressure alterations on the cerebral circulation in newborn dogs

Pneumothorax has been associated with intraventricular hemorrhage in premature infants, although the mechanism for this relationship is not clear. Because alterations in cerebral blood flow are believed to be important in the pathogenesis of intraventricular hemorrhage, the effect of induced pneumothorax and subsequent evacuation on the cerebral circulation in 16 newborn dogs was evaluated. Continuous Doppler ultrasound was used to monitor changes in cerebral blood velocity. Pneumothorax was induced by slow infusion (5 cc/kg/min) or rapid infusion (5 to 10 seconds) of air to reduce mean arterial blood pressure to half of base-line levels. Both methods of pneumothorax induction resulted in significant elevations of central venous pressure and intrapleural pressure, whereas mean arterial blood pressure and cerebral blood velocity decreased significantly. In each group, the pneumothorax was evacuated either by slow withdrawal of air (10 cc/kg/min) or as rapidly as possible. Rapid evacuation of air resulted in an immediate increase in mean arterial blood pressure and cerebral blood velocity to supranormal levels. Slow evacuation led to a more gradual normalization of mean arterial blood pressure and cerebral blood velocity. It is suggested that the precipitous increases in mean arterial blood pressure and cerebral blood velocity following rapid evacuation of a tension pneumothorax may account for the observed association between pneumothorax and intraventricular hemorrhage in premature infants.

Regional cerebral blood flow, cerebral blood velocity, and pulsatility index in newborn dogs

A technique employing a Doppler ultrasound probe to measure cerebral blood velocity was used to study the cerebral circulation continuously in 30 newborn mongrel dogs. Utilizing a transfontanelle approach, the probe was maintained in fixed position throughout a given experiment. In 20 animals, changes in systolic, diastolic, and mean cerebral blood velocity during hypo- and hypercarbia were directly correlated (P less than 0.01) with changes in regional cerebral blood flow (rCBF) determined in 12 regions of the brain by the [14C]iodoantipyrine autoradiography technique. In an additional 10 dogs, multiple determinations of systolic, diastolic, and mean blood velocity were made over a wide range of PaCO2 values and found to be directly related to the PaCO2 (P less than 0.001). These data suggest that changes in cerebral blood velocity are closely related to changes in cerebral blood flow. We also calculated the pulsatility index (PI) from the peak systolic and end diastolic velocities and found a poor, but direct (r = 0.28, P less than 0.05) relationship between the PI and PaCO2 rather than the indirect relationship, which has been suggested in published clinical studies. We conclude that the Doppler technique may be valuable in monitoring dynamic events of the neonatal cerebral circulation if a constant probe position is maintained. Our results suggest, however, that the PI is not a reliable index of cerebral vascular resistance.

Blood-brain barrier permeability to lactic acid in the newborn dog: lactate as a cerebral metabolic fuel

The arteriovenous difference (A-V) method was utilized to assess the permeability of the blood-brain barrier to lactic acid in paralyzed and artificially ventilated newborn dogs. A femoral artery and the sagittal sinus were cannulated to sample arterial and cerebral venous blood simultaneously for measurements of glucose and lactate during normoglycemia, normoglycemia and hyperlactatemia insulin-induced hypoglycemia, or hypoglycemia and hyperlactatemia. During normoglycemia, arterial lactate concentrations remained less than 2 mmoles/liter for up to 2 h; mean A-V lactate was essentially zero. Arterial lactate increased up to 8 mmoles/liter during intravenous infusion of neutralized 10 mM L-lactic acid. During hyperlactatemia, the A-V lactate was directly proportional to the arterial concentration of the metabolite, a finding which is consistent with transport into brain either by simple diffusion or via a carrier with saturability greater than 8 simple diffusion or via a carrier with saturability greater than 8 mmoles/liter. During hypoglycemia (mean arterial glucose=27 mg/dl), A-V glucose was reduced by 71% with a significant increase in A-V lactate at an arterial lactate level of 1.3 mmoles/liter. Hyperlactatemia combined with hypoglycemia resulted in A-V lactate which was 2-3 fold greater than during normoglycemia at similar arterial lactate concentrations. Brain/blood lactate ratios declined by 83% during hypoglycemia compared with normoglycemic ratios, indicating that, once in brain, lactic acid was actively consumed for oxidative processes. These experimental observations may have clinical relevance in newborn human infants when concentrations of lactate in blood often approach or even exceed those of glucose.

Ventricular dimensions of the brain in premature and full-term infants

A total of 120 computed tomographic scans of the brain in premature and full-term infants were reviewed. Of these, 28 were judged to exhibit normal ventricular dimensions, and the bifrontal, bicaudate, and bioccipital indices of the lateral ventricles were determined. The bifrontal and bicaudate indices followed a Gaussian distribution, with mean values of 0.28 +/- 0.07 (SD) and 0.15 +/- 0.03 (SD), respectively, whereas the bioccipital index was uniform in its distribution (range, 0.13 to 0.26). For comparison, corresponding indices were determined in scans of ten infants with clinical evidence of hydrocephalus. Based on these data, guidelines are suggested to distinguish normal and abnormal ventricular dimensions in newborn infants.