Ampicillin versus penicillin in the empiric therapy of extremely low-birthweight neonates at risk of early onset sepsis.

BACKGROUND: There are no comparative data on the impact of different empiric antibiotic regimens on early bowel colonization as well as on clinical efficacy in extremely low-birthweight (ELBW) neonates at risk of early onset sepsis (EOS). METHODS: A subgroup analysis was carried out of ELBW neonates recruited into a two-center, prospective, cluster randomized study comparing ampicillin and penicillin both combined with gentamicin, within the first 72 h of life. A composite primary end-point (need for change of antibiotics within 72 h and/or 7 day all-cause mortality) and the rate and duration of colonization by opportunistic aerobic microorganisms were assessed using hierarchical models corrected for study center and period. RESULTS: In the ampicillin (n= 36) and penicillin (n= 39) groups change of antibiotics, 7 day mortality and the composite end-point occurred at similar rates. Neonatal intensive care unit mortality for infants with gestational age <26 weeks was lower in the ampicillin group. Ampicillin treatment was associated with a higher colonization rate by Klebsiella pneumoniae, including ampicillin-resistant strains. CONCLUSION: Preliminary data indicate an urgent need for adequately powered studies of early antibiotic therapy in the subpopulation of ELBW neonates at risk of EOS.

Clinical parameters predicting failure of empirical antibacterial therapy in early onset neonatal sepsis, identified by classification and regression tree analysis.

BACKGROUND: About 10-20% of neonates with suspected or proven early onset sepsis (EOS) fail on the empiric antibiotic regimen of ampicillin or penicillin and gentamicin. We aimed to identify clinical and laboratory markers associated with empiric antibiotic treatment failure in neonates with suspected EOS. METHODS: Maternal and early neonatal characteristics predicting failure of empiric antibiotic treatment were identified by univariate logistic regression analysis from a prospective database of 283 neonates admitted to neonatal intensive care unit within 72 hours of life and requiring antibiotic therapy with penicillin or ampicillin and gentamicin. Variables, identified as significant by univariate analysis, were entered into stepwise multiple logistic regression (MLR) analysis and classification and regression tree (CRT) analysis to develop a decision algorithm for clinical application. In order to ensure the earliest possible timing separate analysis for 24 and 72 hours of age was performed. RESULTS: At 24 hours of age neonates with hypoglycaemia < or = 2.55 mmol/L together with CRP values > 1.35 mg/L or those with BW < or = 678 g had more than 30% likelihood of treatment failure. In normoglycaemic neonates with higher BW the best predictors of treatment failure at 24 hours were GA < or = 27 weeks and among those, with higher GA, WBC < or = 8.25 x 10(9) L(-1) together with platelet count < or = 143 x 10(9) L(-1). The algorithm allowed capture of 75% of treatment failure cases with a specificity of 89%. By 72 hours of age minimum platelet count < or = 94.5 x 10(9) L(-1) with need for vasoactive treatment or leukopaenia < or = 3.5 x 10(9) L(-1) or leukocytosis > 39.8 x 10(9) L(-1) or blood glucose < or = 1.65 mmol/L allowed capture of 81% of treatment failure cases with the specificity of 88%. The performance of MLR and CRT models was similar, except for higher specificity of the CRT at 72 h, compared to MLR analysis. CONCLUSION: There is an identifiable group of neonates with high risk of EOS, likely to fail on conventional antibiotic therapy.

Low cerebral blood flow velocity and head circumference in infants with severe hypoxic ischemic encephalopathy and poor outcome.

AIMS: To evaluate long-term changes in cerebral blood flow velocity (CBFV) and head circumference in asphyxiated infants. METHODS: CBFV was measured in 83 asphyxiated and 115 healthy term infants in anterior and middle cerebral, basilar and internal carotid artery (ICA) up to the age of 60-149 days. The psychomotor development and head circumference was followed for 18 months. RESULTS. Mean CBFV was increased (p < 0.05) during the first days after asphyxia in infants with severe hypoxic-ischemic encephalopathy (HIE) (n = 25) compared to control group or infants with mild to moderate HIE (n = 58) with maximum values found at the age of 36-71.9 h: in ICA (mean [95% CI]) 31.2 (25.5-36.6) cm/s in severe HIE infants compared to 13.0 (12.2-13.9) cm/s in controls. Decreased (p < 0.0001) mean CBFV developed in severe HIE infants by the age of 21-59 days: in ICA 14.1 (11.5-16.8) cm/s compared to 22.9 (21.4-24.4) cm/s in controls. Infants with severe HIE had similar mean height but lower head circumferences compared to controls (p < 0.05) at the age of 21-59 days. CONCLUSION: The high mean CBFV found in infants with severe HIE during the first days after asphyxia is temporary and low CBFV and head circumference develops by the age of 21-59 days.

Changes in cerebral and visceral blood flow velocities in asphyxiated term neonates with hypoxic-ischemic encephalopathy.

OBJECTIVE: The purpose of this study was to evaluate changes in the Doppler blood flow velocity (BFV) in the cerebral and visceral arteries in asphyxiated term neonates. METHODS: The BFV was measured in 47 asphyxiated and 37 healthy term neonates in the anterior cerebral artery, middle cerebral artery, basilar artery, internal carotid artery, celiac artery (CA), superior mesenteric artery (SMA), and renal artery (RA) up to the age of 60 to 149 days. RESULTS: At the age of 12 to 120 hours after asphyxia, the mean BFV had increased, and the resistive index (RI) had decreased (P < .05) in all cerebral arteries in neonates with severe hypoxic-ischemic encephalopathy (HIE) compared with the control group. In neonates with severe HIE, the mean BFV in the RA had significantly decreased at the age of 3 to 240 hours, and the RI had increased at the age of 24 to 240 hours, normalizing by the age of 21 to 59 days compared with the control group (P < .05). In the SMA, a decreased mean BFV was found in neonates with severe HIE compared with those with mild to moderate HIE only at the age of 24 to 36 hours. In neonates with mild to moderate HIE, the mean BFV had increased in the SMA and CA compared with the control group at the age of 2 to 11.9 hours. CONCLUSIONS: A severe alteration of the cerebral and visceral BFV takes place during the first days after asphyxia in neonates with different severities of HIE.