ABSTRACT.Objective. Candida and coagulase-negative staphylococci are emerging pathogens associated with focal intestinal perforation (FIP) and necrotizing enterocolitis (NEC) in neonates. The objective of this study was to determine whether there are significant differences in the predominant pathogens in culturepositive cases of peritonitis associated with FIP compared with NEC in neonates.Methods. A retrospective cross-sectional study was conducted of neonates with peritoneal culture-positive peritonitis associated with FIP or NEC over a 12-year study period (1989 -2000). Cases with peritonitis were identified from a microbiology database. NEC was defined by radiologic evidence of pneumatosis intestinalis or portal venous gas or by pathology reports or surgical operative notes describing large areas of transmural bowel necrosis. FIP was defined as a <1-cm intestinal perforation surrounded by otherwise normal tissue in the absence of NEC.Results. Thirty-six cases of FIP were compared with 80 cases of NEC. Birth weight and gestational age were significantly lower in infants with FIP compared with NEC. Age at intestinal perforation and case fatality rates were similar between FIP and NEC. There were striking differences in the distribution of predominant pathogens associated with peritonitis in NEC and FIP cases. Enterobacteriaceae were present in 60 (75%) of 80 NEC cases compared with 9 (25%) of 36 FIP cases. In contrast, Candida species were found in 16 (44%) of 36 FIP cases compared with 12 (15%) of 80 NEC cases, and coagulasenegative staphylococci were present in 18 (50%) of 36 FIP cases versus 11 (14%) of 80 NEC cases. There were no significant differences between FIP and NEC cases for the presence of Enterococcus species (28% vs 23%) or anaerobes (3% vs 6%). Stratified analysis for birth weight <1200 g found similar significant differences in the predominant pathogens for FIP (n ‫؍‬ 29) and NEC (n ‫؍‬ 38).

Term and near-term infants with pulmonary hypertension are frequently treated with inhaled nitric oxide. This therapy can be delivered with highfrequency ventilation, but there has been limited study of the relative effectiveness of high-frequency jet ventilation and high-frequency oscillatory ventilation.Objective: To compare short-term clinical outcomes of neonates with pulmonary hypertension treated with inhaled nitric oxide plus either high-frequency jet ventilation or high-frequency oscillatory ventilation.Study Design: Study infants met the following criteria: X35 weeks gestation, respiratory failure with pulmonary hypertension, no congenital malformations and treatment in the first week of life with inhaled nitric oxide plus either high-frequency jet ventilation (n ¼ 22) or high-frequency oscillatory ventilation (n ¼ 43). Data were collected from medical records. Result:The jet ventilation and oscillatory ventilation groups were similar in terms of gestational age, but the jet ventilation group had less severe respiratory illness (that is, lower oxygenation index) just prior to initiation of the combination of nitric oxide and high-frequency ventilation. The jet ventilation group spent more hours on inhaled nitric oxide (71.4 versus 40.8; P ¼ 0.004) but was less likely to require extracorporeal membrane oxygenation (2(9%) versus 19(44%); P ¼ 0.004). No difference was found in the ages at which oxygen and high-frequency ventilation were discontinued. Keywords: persistent pulmonary hypertension; inhaled nitric oxide; hypoxic respiratory failure; high-frequency ventilation; high-frequency oscillatory ventilation; high-frequency jet ventilation Introduction Persistent pulmonary hypertension of the newborn (PPHN) refers to a lack of normal cardiopulmonary adaptation following delivery, 1 including persistence of the elevated pulmonary vascular resistance that is characteristic of fetuses. 2 Most often PPHN occurs in infants with meconium aspiration syndrome (34 to 51%), pneumonia/sepsis (20 to 23%), idiopathic PPHN (17 to 25%), congenital diaphragmatic hernia (10 to 15%) or respiratory distress syndrome (9 to 12%). 3,4 Prior to the introduction, in the late 1990s, of inhaled nitric oxide (iNO), therapies for PPHN included induced alkalosis, supplemental oxygen, mechanical ventilation and neuromuscular blockade; and patients who failed to respond to these measures were treated with extracorporeal membrane oxygenation (ECMO). 5 iNO has been shown to reduce the need for ECMO in term and near-term neonates with pulmonary hypertension. 3,4,6,7 High-frequency ventilation (HFV) has been used with increasing frequency for PPHN, 8 and when combined with iNO results in an acute rise in arterial oxygen saturation, 9 and reduces the likelihood of ECMO treatment. 10 Studies of iNO delivered by HFV have, to date, utilized high-frequency oscillatory ventilation (HFOV). However, since patients treated with high-frequency jet ventilation (HFJV), as compared to conventional ventilation, require lower peak pressures to achieve t...