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The objective of this study was to document the pattern of bowel gas decompression and mediastinal shift in infants with congenital diaphragmatic hernia (CDH) before delayed surgical correction. The setting was the Neonatal Intensive Care Unit, Royal Alexandra Hospital, Edmonton. The design was a retrospective review of radiographs and charts of all infants with CDH between January 1990 and December 1993. Bowel gas in the upper and middle one third of the hemithorax was classified as grade III and grade II, respectively. Bowel gas in the lower one third of the hemithorax or absent bowel gas was classified as grade I. All the infants showed partial return of the contralateral shift in the mediastinum toward the midline when comparing the admission chest radiographs with the immediate preoperative films. Complete return of the mediastinum to normal (using the first postoperative radiograph as the gold standard) occurred in all but 1 of the 10 infants on extracorporeal membrane oxygenation (ECMO) (90%) and 7 of 13 (54%) of conventionally treated infants (P = .12). At the time of the first radiograph, a similar proportion of non-ECMO and ECMO infants (61% versus 70%, respectively) had either grade II or III bowel gas patterns. By 72 hours none of the non-ECMO-treated infants (who were paralyzed with muscle relaxants) had bowel gas in the middle and upper one third of the hemithorax. In contrast, 66% of infants on ECMO still had a grade II bowel gas pattern at 72 hours (P < .05), with 4 infants showing an actual increase in bowel gas after discontinuation of muscle relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)

Study objective. To change physician attitudes and practices regarding the routine use of local and regional anesthesia for newborn circumcision. Design. Interventional study, followed by an audit of physician practice over a 1-month period, 1 year following interventions. Setting. The newborn nurseries of the Womens' Pavilion, Royal Alexandra Hospital, Edmonton. Interventions. A broad range of awareness and educational programs were directed at physicians who perform newborn circumcisions, including posters, newsletters, presentations at grand rounds, video recordings, and practical "hands-on" demonstration of the techniques of local anesthesia to the prepuce and dorsal penile nerve block. Results. Only one physician was using local analgesia for newborn circumcision prior to the introduction of the educational program. The audit, performed 12 months later, documented 46 circumcisions performed by 22 physicians, each performing between 1 and 6 circumcisions (median = 1). Sixteen of the 22 physicians (73%) used either local anesthesia to the prepuce (19 cases) or dorsal penile nerve block (13 cases) during circumcisions. Thus, local analgesia was used in 66% (32/48) of all circumcisions. Six physicians, performing 16 circumcisions, did not use any form of analgesia. Conclusions. This simple educational program has been associated with a remarkable change in attitudes and practice regarding local analgesia for neonatal circumcision. Our ideal objective, which we hope to achieve through repeated education and practical demonstrations of the techniques to interested physicians, is that all newborn circumcisions are performed under local or regional anesthesia in our institution.

We studied the hemodynamic responses of peritoneal dialysis (PD) in three children following open heart surgery. Hemodynamic measurements were made prior to a dialysis run, following the instillation of dialysis solution (20 ml/kg), and immediately prior to and 5 min after drainage of the peritoneal cavity. The same protocol was repeated 48 h later. There was a significant increase in right atrial pressure (RAP) and mean pulmonary artery pressure upon instillation of the dialysate into the peritoneal cavity (p less than 0.01). However, cardiac index, mean arterial blood pressure (MAP), systemic (SVRI) and pulmonary vascular resistances (PVRI), left atrial pressure (LAP), and oxygen saturation did not change significantly. There were no significant differences between responses in the initial study and that performed 48 h later. PD is associated with modest right-sided hemodynamic changes which, in this small group of patients, did not compromise patient care.

AIM--To examine the haemodynamic effects of intravenous magnesium sulphate on an animal model of neonatal pulmonary hypertension induced by hypoxia. METHODS--The cardiac index (Q), pulmonary arterial pressure (PAP), systemic arterial pressure (SAP), and pulmonary (PVRI) and systemic (SVRI) vascular resistance indices were measured in nine newborn piglets (including three controls). Pulmonary hypertension was induced by lowering the FIO2 to 0.12-0.14, after which there was a significant increase in PAP and PVRI (37% and 142%, respectively; p < 0.01) and a significant fall in SAP and Q (30% and 33%, respectively; p < 0.01). RESULTS--Magnesium sulphate was infused intravenously as four doses of 25 mg/kg, 15 minutes apart, which resulted in a significant mean (SD) increase in serum magnesium (0.83 (0.07) mmol/l to 1.82 (0.19) mmol/l; p < 0.01). After the initial dose SAP, SVRI, PAP and PVRI decreased, but not significantly. Each subsequent dose of (50, 75, 100 mg/kg) was accompanied by further significant reductions in these variables from control baseline (p < 0.05). The PVRI:SVRI ratio remained unchanged throughout. Inhaled nitric oxide (NO) 40 ppm was administered after the last dose of magnesium sulphate. The PVRI:SVRI significantly decreased (p < 0.05), indicating that reversible pulmonary hypertension remained after a maximum dose of magnesium sulphate. CONCLUSIONS--Unlike NO, magnesium sulphate is not a selective pulmonary vasodilator and may lead to deleterious effects on systemic pressures in critically ill newborns.

We describe a case of fatal hypoxic-ischemic encephalopathy, leading to brain death following the modified Fontan procedure in a child with asymptomatic subclavian steal syndrome (SSS). This patient's brain death was most likely multifactorial in view of his postoperative course. However, we believe that the presence of the SSS contributed to the abnormal cerebral circulation during surgery and postoperatively, leading to brain death. The presence of SSS in patients undergoing an open-heart procedure may be a risk factor for cerebral ischemia or brain death.

Editor,—Drawstrings on children’s clothing are a hidden hazard that can lead to death and injury when they catch on cribs, playground equipment, vehicles, and escalators.1-3Although rare, 17 deaths and 42 non-fatal accidents involving the entanglement of drawstrings on children’s outerwear were reported from 1985–95 in the United States. At least 12 of these incidents involved the entanglement of drawstrings in the doors of school buses.4 The recent unrelated deaths of two young boys in Ireland, following entanglement of part of their outercoats in the door of a school bus5 and rotating powershaft of a tractor,6 prompted us to evaluate the safety of children’s outerwear. We evaluated the safety of different designs of children’s winter outerwear …

The recent National Institutes of Health Consensus Development Conference on ANS was strongly supportive of the use of ANS, even for 24 hours but, if possible, for 48 hours, in all fetuses between 24 and 34 weeks of gestation and at risk of preterm delivery regardless of race, gender, or the availability of surfactant replacement. For preterm rupture of membranes at less than 30 to 32 weeks, the use of ANS was also recommended in the absence of amnionitis, and patients eligible for tocolytic therapy were also deemed eligible for ANS. Thus the currently available literature indicates that pediatricians should encourage obstetricians to provide ANS in high-risk pregnancies, as outlined in the proposed National Institutes of Health guidelines. Even if a full 48-hour course of ANS cannot be achieved, ANS given less than 24 hours before delivery is associated with a decreased incidence of intraventricular hemorrhage and periventricular leukomalacia. In addition, we propose that investigators, reviewers, and editors ensure uniformly high maternal ANS exposure, consistent with the realities of clinical practice, when designing, evaluating, and publishing clinical trials with outcomes (e.g., RDS, intraventricular hemorrhage, periventricular leukomalacia, bronchopulmonary dysplasia, and death) that can be significantly affected by ANS. Otherwise, studies will continue to be performed on infants who, as fetuses, were deprived of treatment that may have prevented or ameliorated the disorder being assessed. Studies with an infrequent use of ANS may not be applicable or generalizable to an era when the use of ANS is an essential part of perinatal practice. Future trials should document both ANS use and the reasons for failure to achieve an acceptable level of such treatment.

We tested a number of pulse oximeters in a neonatal ICU to assess their performance as continuous monitors. Using a computer-based data acquisition system and a movement sensor, we determined the proportion of time that the oximeter was unreliable as the duration of monitored time that the oximeter heart rate (HR) differed from a "true" HR by greater than 10 beat/min using each of the oximeters in both their short and long averaging mode. The tested devices were found to be unreliable for 11.9% to 25% in the short averaging mode, and from 13.8% to 29% in the longer averaging mode. Most of the HR discrepancy was secondary to movement of the extremity. A newer model of one of the devices, which uses ECG R-wave detection to trigger optical pulse scanning, was associated with markedly reduced motion artifact (2.1% to 4.1%) when it accurately interpreted HR. The response of the devices to an acute loss of pulsation revealed differences in design and performance with some oximeters indicating zero saturation and others continuing to display a value while indicating a "low quality signal." Pulse oximeters are a valuable adjunct to clinical oxygen monitoring and, when properly applied and reliably indicating the infant's HR, will accurately reflect arterial saturation (r = .8, p less than .0001). ECG synchronization appears to reduce motion artifact when the ECG R-wave is detected.

We studied the hemodynamic effects of acute alterations in PaCO2 in ten ventilator-dependent children after open heart surgery. Despite end-tidal CO2 monitoring, five children inadvertently developed PaCO2 greater than 50 torr during the study. Increasing and decreasing PaCO2 in these children resulted in significant parallel changes in cardiac index (CI), oxygen delivery, physiologic shunt, mean pulmonary pressure, and right ventricular stroke work index, and inverse changes in systemic vascular resistance index (p less than .01). No significant hemodynamic changes were observed with alterations in PaCO2 in children whose PaCO2 remained less than 50 torr. These findings are partly related to significantly larger reductions in PaCO2 which occurred in the hypercarbic children compared to the others (25 vs. 12 torr; p less than .001). Heart rate, mean arterial BP, and venous filling pressures did not change significantly in either group. We conclude that mean alterations in PaCO2 less than or equal to 12 torr (range 28 to 50) have no significant effect on CI in children after open heart surgery. However, moderate hypercarbia and its correction to a mean PaCO2 of 30 torr are associated with significant effects on central hemodynamics. Moreover, no significant changes in the commonly monitored physiologic variables were observed despite large variations in PaCO2.

Anterior thigh, pretibial and midfoot surface temperatures (MFT) were measured by an infrared thermometer in 17 children after open heart surgery. Core temperature was measured by pulmonary artery thermistor and cardiac index (CI) by thermodilution. No significant relationship existed between the previous hour's urinary output (ml/m2.h) and either systemic vascular resistance index (SVRI) and CI. MFT was inversely related to SVRI (r = -5.3; p less than .0001) but not to CI. The core/peripheral temperature gradient correlated directly with SVRI (r = .38, p less than .01) and inversely with CI (r = -.28, p less than .05). There was no improvement in any of the correlation coefficients when hemodynamic variables were tested against temperature gradients from core to thigh and thigh to foot. Although these relationships are statistically significant, we conclude that they are not strong enough to be of value in predicting central hemodynamic status in children after heart surgery.

The amino acid sequences of two low molecular weight proteinase inhibitors from Russet Burbank potatoes have been determined. One of these, a chymotrypsin inhibitor, is a peptide of 52 amino acid residues, while the second inhibitor, which is specific for trypsin, contains 51 amino acid residues. These peptides are highly homologous, differing at only nine positions. At position 38, the chymotrypsin inhibitor possesses leucine and the trypsin inhibitor an arginine. This difference probably represents the P1 sites, which are consistent with the respective specificities of the two inhibitors. The inhibitors are also homologous with potato inhibitor II and with an inhibitor previously isolated from eggplants.

The solution conformation of potato carboxypeptidase inhibitor (CPI) has been investigated by 1H NMR spectroscopy. The spectrum is assigned in a sequential manner by using two-dimensional NMR techniques to identify through-bond and through-space (less than 5 A) connectivities. A set of 309 approximate interproton distance restraints is derived from the two-dimensional nuclear Overhauser enhancement spectra and used as the basis of a three-dimensional structure determination by a combination of metric matrix distance geometry and restrained molecular dynamics calculations. A total of 11 converged distance geometry structures were computed and refined by using restrained molecular dynamics. The average atomic root mean square (rms) difference between the final 11 structures and the mean structure obtained by averaging their coordinates is 1.4 +/- 0.3 A for residues 2-39 and 0.9 +/- 0.2 A for residues 5-37. The corresponding values for all atoms are 1.9 +/- 0.3 and 1.4 +/- 0.2 A, respectively. The larger values for residues 2-38 relative to those for residues 5-37 arise from the fact that the positions of the N- (residues 1-4) and C- (residues 38-39) terminal tails are rather poorly determined, whereas those of the core of the protein (residues 5-37) are well determined by the experimental interproton distance data. The computed structures are very close to the X-ray structure of CPI in its complex with carboxypeptidase, and the backbone atomic rms difference between the mean of the computed structures and the X-ray structure is only 1.2 A. Nevertheless, there are some real differences present which are evidenced by significant deviations between the experimental upper interproton distance limits and the corresponding interproton distances derived from the X-ray structure. These principally occur in two regions, residues 18-20 and residues 28-30, the latter comprising part of the region of secondary contacts between CPI and carboxypeptidase in the X-ray structure.

Six anesthetized paralyzed cats with normal lungs were ventilated by high-frequency chest wall compression (HFCWC) at 5 Hz using a single-chamber circumferential cuff enclosing the thorax from the axillae to the xiphisternum. PaCO2 during HFCWC + PEEP (3 cm H2O) was significantly (p less than .0005) lower compared with conventional mechanical ventilation (CMV). End-expiratory lung volume (VL) during HFCWC + PEEP was significantly (p less than .001) lower than VL during CMV + PEEP but was higher than VL during CMV without PEEP. After the cats' lungs were stiffened by repeated saline lavage, CMV + PEEP at a mean airway pressure (Paw) of 10 cm H2O was compared with HFCWC + continuous positive airway pressure (CPAP) at an equal or lower Paw. A significant decrease in PaCO2 (p less than .02) during HFCWC occurred but no significant differences were observed in PaO2, VL, or compliance. Arterial BP and cardiac output were similar between CMV + PEEP and HFCWC + CPAP. In cats with normal lungs, VL can be maintained by applying CPAP during HFCWC, and in those with injured lungs, HFCWC + CPAP produces comparable gas exchange at a Paw equal to or lower than that used during CMV + PEEP.