Focal intestinal perforation in the extremely-low-birth-weight infant.

The purposes of this report were to (1) document the clinical and laboratory features of 11 extremely-low-birth-weight (ELBW) infants with focal intestinal perforation and (2) investigate the clinical events possibly associated with these perforations by examining matched pairs of infants with and without focal intestinal perforation. During the study period 173 infants with birth weights between 600 and 1000 gm were admitted to the neonatal intensive care nursery. Eleven of these ELBW infants had focal intestinal perforations and formed the study group. These infants were matched with 11 ELBW infants who did not have intestinal perforations or signs of inflammatory bowel disease. The matched pairs were similar in all respects except for a significantly higher percent increase in blood urea nitrogen level after treatment with indomethacin (Wilcoxon signed-rank test, p < 0.02) in infants with intestinal perforation. At laparotomy the perforations were noted to be focal, often multiple, and on the antimesenteric border of the distal ileum. None of the infants showed clinical, radiographic, or intraoperative findings that were consistent with classifications for necrotizing enterocolitis (NEC). The incidence of focal intestinal perforation in ELBW infants was 6% versus 2% for typical NEC. In addition, four of the 11 infants with intestinal perforation had positive cultures for either Staphylococcus epidermidis or Candida albicans, whereas none of the infants without perforation had positive cultures during the study period (Fisher's exact test, p < 0.09). We conclude that the clinical presentation and the characteristic intestinal lesions in this group of ELBW infants are distinct from those in typical cases of NEC.(ABSTRACT TRUNCATED AT 250 WORDS)

Intermittent mandatory ventilation with continuous negative pressure compared with positive end-expiratory pressure for neonatal hypoxemia.

The use of continuous negative pressure was prospectively studied in 30 preterm and term hypoxemic (PaO2 < 45 mm Hg) neonates. Infants were randomly assigned to either positive end-expiratory pressure or continuous negative pressure if conventional positive pressure ventilation failed to improve oxygenation. Crossover to the alternative therapy occurred if infants remained hypoxemic after 2 hours. In the continuous negative pressure group, 2 (13%) crossed over to positive end-expiratory pressure, whereas 11 (73%) in the positive end-expiratory pressure group crossed over to continuous negative pressure (p = 0.003). Only five patients remained in the positive end-expiratory pressure group 36 hours after randomization. Compared with positive end-expiratory pressure, continuous negative pressure significantly increased PaO2 (69 +/- 17 mm Hg vs 36 +/- 8 mm Hg) and arterial-alveolar ratio (0.098 +/- 0.070 vs 0.057 +/- 0.014) 30 minutes after randomization and after crossover to continuous negative pressure (60 +/- 12 mm Hg vs 37 +/- 5 mm Hg, and 0.154 +/- 0.096 vs 0.058 +/- 0.009). The use of continuous negative pressure did not increase morbidity. Overall survival was 83.3%. Only three infants were referred to extracorporeal membrane oxygenation. Rescue therapy with continuous negative pressure is effective in infants with refractory hypoxemia and may be considered before referral for extracorporeal membrane oxygenation.

Reintroduction of continuous negative pressure ventilation in neonates: two-year experience.

Continuous negative pressure ventilation utilizes subatmospheric pressure around the thorax to improve oxygenation. It has not been routinely used since the mid-1970s. We treated 37 infants with the combination of continuous negative pressure (CNP) and intermittent mandatory ventilation (IMV), after failing to attain a PaO2 of greater than or equal to 50 torr on IMV alone. Lung diseases included pulmonary interstitial emphysema (PIE), respiratory distress syndrome (RDS), and pulmonary artery hypertension (PAH) due either to meconium aspiration syndrome (MAS) or other causes (non-MAS). All infants had evidence of severe parenchymal pulmonary disease, or pulmonary artery hypertension resulting in persistent hypoxemia and hypotension. In the PIE group, CNP was started later in the course of the disease, and both positive pressure and oxygen were maintained for a longer period. The group of infants with non-MAS PAH required CNP and positive pressure ventilation for the shortest period of time. The infants with PIE also had a greater incidence of bronchopulmonary dysplasia (BPD) and intraventricular hemorrhage (IVH). In addition, three patients with PIE died. In the non-MAS patients with PAH, no complications and no deaths occurred. The response to CNP was a rapid improvement in oxygenation in all groups with the greatest increase of PaO2 in the non-MAS PAH infants: from 30 torr prior to the initiation of CNP to 140 torr within 30 minutes. No significant changes in pH or PaCO2 occurred in any group. Significant decreases in ventilator rate, mean airway pressure (Paw) and FIO2 in peak inspiratory pressure were possible by 12 hours of CNP.(ABSTRACT TRUNCATED AT 250 WORDS)

Continuous negative pressure in the treatment of infants with pulmonary hypertension and respiratory failure.

We report the successful use of continuous negative pressure (CNP) with standard intermittent mandatory ventilation (IMV) in five patients suffering from respiratory failure and persistent pulmonary hypertension of the newborn (PPHN). These infants all fulfilled criteria for use of extracorporeal membrane oxygenation (ECMO) with PaO2 less than 40 torr, alveolar-arterial oxygen difference (AaDO2) greater than 620 mm Hg, and oxygenation index (OI) greater than 50. Despite a considerable amount of conventional ventilation with mean airway pressures (PAW) between 14 and 26 cm water, none of these patients were able to improve oxygenation. All infants demonstrated significant improvement in ventilation requirements after initiation of CNP as reflected by a decrease in PAW, proximal inspiratory pressure (PIP), and IMV. Oxygenation dramatically improved in all infants. All five patients survived without any pulmonary or neurological complications at discharge. Availability of CNP may circumvent the need for ECMO in infants with severe lung disease and PPHN.