Background

Necrotizing enterocolitis is associated with high morbidity and mortality among infants admitted for intensive care. The factors associated with mortality and catastrophic presentation remain poorly understood.

Objective

To describe the factors associated with mortality in infants with necrotizing enterocolitis and to quantify the degree to which catastrophic presentation contributes to mortality in infants with necrotizing enterocolitis.

Methods

We performed a retrospective review of the Pediatrix's Clinical Data Warehouse (1997-2009) to compare the demographic, therapeutic and outcome characteristics of infants who survived NEC versus those who died. Associations were tested by bivariate and multivariate analysis.

Results

In a total cohort of 560,227 infants, there were 2661 cases (17%) of surgically treated and 6460 (42%) of medically treated necrotizing enterocolitis; 1505 (16.5%) died. In multivariate analysis, the factors associated with death (P<0.01 in analysis) were lower estimated gestational age, lower birth weight, a need for assisted ventilation on the day of diagnosis of NEC, a need for vasopressors at the time of diagnosis, and Black race. Patients who received only ampicillin and gentamicin on the day of diagnosis were less likely to die.

Two thirds of NEC deaths occurred quickly (<7 days from diagnosis), with a median time of death of one day from time of diagnosis. Infants who died within 7 days of diagnosis had a higher birth weight, more often required vasopressors and more often were treated with high frequency ventilation at the time of diagnosis compared to patients who died at 7 or more days. Although mortality decreased with increasing gestational age, the proportion of deaths that occur within 7 days was relatively consistent (65-75 percent of the patients who died) across all gestational ages.

Conclusions

Mortality among infants who have necrotizing enterocolitis remains high and infants who die of necrotizing enterocolitis commonly (66%) die quickly. Most of the factors associated with mortality are related to immaturity, low birth weight and severity of illness.

Background

Coagulase-negative staphylococci (CoNS) are the most commonly isolated pathogens in the neonatal intensive care unit (NICU). CoNS infections are associated with increased morbidity including neurodevelopmental impairment.

Objective

Describe the epidemiology of CoNS infections in the NICU. Determine mortality among infants with definite, probable, or possible CoNS infections.

Methods

We performed a retrospective cohort study of all blood, urine, and cerebrospinal fluid cultures from infants <121 postnatal days.

Setting

248 NICUs managed by the Pediatrix Medical Group from 1997 to 2009.

Results

We identified 16,629 infants with 17,624 episodes of CoNS infection: 1734 (10%) definite, 3093 (17%) probable, and 12,797 (73%) possible infections. Infants with lower gestational age and birth weight had a higher incidence of CoNS infection. Controlling for gestational age, birth weight, and 5-minute Apgar score, infants with definite, probable, or possible CoNS infection had lower mortality—OR=0.74 (95% confidence interval; 0.61, 0.89), OR= 0.68 (0.59, 0.79), and OR=0.69 (0.63, 0.76)—compared to infants with negative cultures (P<0.001). No significant difference in overall mortality was found in infants with definite CoNS infection compared to those with probable or possible CoNS infection—OR=0.93 (0.75, 1.16) and OR=0.85 (0.70, 1.03), respectively.

Conclusions

CoNS infection was strongly related to lower gestational age and birth weight. Infants with clinical sepsis and culture-positive CoNS infection had lower mortality rates than infants with clinical sepsis and negative blood culture results. No difference in mortality between infants diagnosed with definite, probable, or possible CoNS infection was observed.

Objective

The purpose of this study is to examine the results of repeat lumbar puncture in infants with initial positive cerebrospinal fluid (CSF) cultures in order to determine the clinical characteristics and outcomes of infants with repeat positive cultures.

Study Design

Cohort study of infants with an initial positive CSF culture undergoing repeat lumbar puncture between 1997 and 2004 at 150 neonatal intensive care units managed by the Pediatrix Medical group. We compared the clinical outcomes of infants with repeat positive cultures and infants with repeat negative cultures.

Result

We identified 118 infants with repeat CSF cultures. Of these, 26 infants had repeat positive cultures. A higher proportion with repeat positive cultures died compared to those with repeat negative cultures, 6/23 (26%) vs. 6/81 (7%), respectively (p=0.02).

Conclusion

Among infants with a positive CSF culture, a repeat positive CSF culture is common. The presence of a second positive culture is associated with increased mortality.

Background

Preterm birth is increasing worldwide, and late preterm births, which comprise more than 70% of all preterm births, account for much of the increase. Early and late onset sepsis results in significant mortality in extremely preterm infants, but little is known about sepsis outcomes in late preterm infants.

Methods

This is an observational cohort study of infants < 121 days of age (119,130 infants less than or equal to 3 days of life and 106,142 infants between 4 and 120 days of life) with estimated gestational age at birth between 34 and 36 weeks, admitted to 248 neonatal intensive care units in the United States between 1996 and 2007.

Results

During the study period, the cumulative incidence of early and late onset sepsis was 4.42 and 6.30 episodes per 1000 admissions, respectively. Gram-positive organisms caused the majority of early and late onset sepsis episodes. Infants with early onset sepsis caused by Gram-negative rods and infants with late onset sepsis were more likely to die than their peers with sterile blood cultures (OR 4.39, 95% CI 1.71–11.23, P=0.002; and OR 3.37, 95% CI 2.35–4.84, P<0.001, respectively).

Conclusion

Late preterm infants demonstrate specific infection rates, pathogen distribution, and mortality associated with early and late onset sepsis. The results of this study are generalizable to late preterm infants admitted to the special care nursery or neonatal intensive care unit.

Objective

Describe cerebrospinal fluid parameters in infants with culture-proven Group B streptococcal meningitis in the era of intrapartum antibiotic prophylaxis.

Study Design

Cohort study of the first lumbar puncture from 13,495 infants cared for at 150 neonatal intensive care units. We compared cerebrospinal fluid parameters [white blood cell count, red blood cell count, glucose, and protein], demographics, and outcomes between infants with and without Group B streptococcal meningitis.

Results

We identified 46 infants with Group B streptococcal meningitis. The median cerebrospinal fluid white blood cell count was 271 cells/mm3 for infants with Group B streptococcal meningitis and 6 cells/mm3 for infants without meningitis (p=0.0001). Of the infants with Group B streptococcal meningitis, 9/46 (20%) had negative blood cultures. Meningitis complicated 22/145 (15%) of episodes of early onset Group B streptococcal sepsis and 13/23 (57%) of episodes of late onset Group B streptococcal sepsis.

Conclusions

Group B streptococcal meningitis occurs in the presence of negative blood cultures. In hospitalized infants who undergo a lumbar puncture, Group B streptococcal sepsis is frequently complicated by GBS meningitis.

Background

Cerebrospinal fluid (CSF) findings are often used to diagnose meningitis in neonates given antibiotics before the lumbar puncture is performed. Traumatic lumbar punctures are common and complicate interpretation of CSF white blood cell counts. The purpose of this study is to evaluate the diagnostic utility of adjusting CSF white blood cell counts based on CSF and peripheral red blood cell counts.

Methods

Cohort study of lumbar punctures performed between 1997 and 2004 at 150 neonatal intensive care units managed by the Pediatrix Medical group. Traumatic lumbar punctures were defined as CSF specimens with ≥500 red blood cells/mm3. CSF white blood cell counts were adjusted downward for traumatic lumbar punctures using several commonly used methods. We calculated sensitivity, specificity, likelihood ratios, and area under the receiver operating characteristic curve of unadjusted and adjusted CSF white blood cell counts for predicting meningitis in neonates with traumatic lumbar punctures.

Results

Of 6,374 lumbar punctures, 2,519 (39.5%) were traumatic. 114/6,374 (1.8%) were positive for meningitis; 50 neonates with traumatic lumbar punctures had meningitis. The areas under the receiver operating characteristic curve for white blood cell count unadjusted and adjusted by all methods were similar.

Conclusions

Adjustment of CSF white blood cell counts to account for increased red cells does not improve diagnostic utility. Adjustment can result in loss of sensitivity with marginal gain in specificity. Adjustment of WBC counts in the setting of a traumatic lumbar puncture does not aid in the diagnosis of bacterial and fungal meningitis in neonates.

Objective:

Cerebrospinal fluid parameters are of great importance in diagnosing meningitis, but normal values for preterm neonates are based on small, single-center studies. We sought to determine current values for preterm neonate cerebrospinal fluid parameters and assess the association of cerebrospinal fluid parameters with culture proven meningitis.

Study Design:

Cohort study of the first lumbar puncture from 4,632 neonates <34 weeks gestation performed in the years 1997-2004 at 150 neonatal intensive care units managed by the Pediatrix Medical Group.

Results:

We identified 95 cases of meningitis from the 4,632 lumbar punctures. The area under the receiver operating characteristic curves for white blood cell count, glucose, and protein were 0.80, 0.63, and 0.72 respectively for prediction of culture proven meningitis.

Conclusion:

Cerebrospinal fluid parameters used to diagnose meningitis in the absence of dependable cerebrospinal fluid cultures are unreliable. Caution should be employed when interpreting cerebrospinal fluid parameters in the premature neonate.

Background:

When used during extracorporeal membrane oxygenation (ECMO), jugular venous bulb catheters, known as cephalad cannulae, increase venous drainage, augment circuit flow and decompress cerebral venous pressure. Optimized cerebral oxygen delivery during ECMO may contribute to a reduction in neurological morbidity. This study describes the use of cephalad cannulae and identifies rudimentary data for jugular venous oxygen saturation (JVO2) and arterial to jugular venous oxygen saturation difference (AVDO2) in this patient population.

Results:

Patients on venoarterial (VA) ECMO displayed higher JVO2 (P < 0.01) and lower AVDO2 (P = 0.01) than patients on venovenous (VV) ECMO (P < 0.01). During VV ECMO, JVO2 was higher and AVDO2 lower when systemic pH was < 7.35 rather than > 7.4 (P = 0.01). During VA ECMO, similar differences in AVDO2 but not in JVO2 were observed at different pH levels (P = 0.01).

Conclusions:

Jugular venous saturation and AVDO2 were influenced by systemic pH, ECMO type and patient age. These data provide the foundation for normative values of JVO2 and AVDO2 in neonates and children treated with ECMO.