Delivery room management of the meconium-stained newborn.

Review of all medical literature dealing with delivery room management of meconium-stained infants. Additionally, the author contacted multiple individuals involved historically or clinically with the published studies or the persons who developed treatment guidelines. Although many therapies have been suggested as being effective, none have been definitively proven efficacious by the gold standard: a large, randomized, controlled trial (RCT). Further adequate investigations (RCTs) need to be performed to assess whether proposed management schemes are of benefit in the care of meconium-stained newborn infants.

Role of multiple site blood cultures to document the clearance of bacteremia in neonates.

OBJECTIVE: To evaluate the usefulness of two-site blood cultures for the documentation of bacterial clearance during initial treatment of culture proven neonatal sepsis. DESIGN/METHODS: Clinical data were prospectively collected for 216 neonates who had blood cultures drawn for evaluation of possible sepsis. A positive diagnostic blood culture was followed by repeat blood cultures from two different peripheral sites after initiation of antimicrobial therapy. RESULTS: Follow-up two-site cultures were drawn on 25 occasions at a median interval of 3 days after start of antimicrobial therapy for culture-proven sepsis in 15 neonates. On 12 occasions, follow-up blood cultures were both negative. On eight occasions, follow-up blood cultures grew the same organisms from both sites. However, follow-up two-site cultures on five occasions in four of the 15 infants grew organisms from one site but not the second site. CONCLUSIONS: Two-site blood cultures seem necessary to document bacterial clearance in response to antimicrobial therapy for culture-proven sepsis, and may help determine the appropriate duration of antimicrobial therapy by reducing false-negative results.

A study of the role of multiple site blood cultures in the evaluation of neonatal sepsis.

BACKGROUND: The optimal number of blood cultures needed to document sepsis in an ill neonate has undergone little critical evaluation. Multiple site cultures may improve pathogen detection if intermittent bacteremia occurs, or if a low density of bacteria is present in the blood. We hypothesized, however, that bacterial clearance is slower and bacteremia more continuous in septic neonates, so that a single site blood culture should be sufficient to accurately document true septicemia. OBJECTIVE: To determine the need for multiple site blood cultures in the evaluation of neonates for sepsis. DESIGN/METHODS: Clinical data were prospectively collected for 216 neonates who had 269 pairs of blood cultures taken from two different peripheral sites for the evaluation of possible sepsis. A minimum of 1 ml of blood was obtained from the two peripheral sites within 15-30 min of each other. Based on prior retrospective data, we determined that 203 infants would need to have two site blood cultures to demonstrate a significant improvement in pathogen detection at an alpha of 0.05 and a beta of 0.20 (80%) power. RESULTS: A total of 186 culture pairs were taken for evaluation of early-onset sepsis in 186 neonates, while 83 pairs were drawn for evaluation of late-onset sepsis in 43 neonates. In all, 21 neonates from the late-onset group were evaluated more than once, and 12 neonates were evaluated for both early- and late-onset sepsis. In all, 20 (9.2%) of 216 neonates had 22 episodes of culture-proven sepsis at a median age of 18 days. All neonates with positive cultures had the same organism with a similar sensitivity pattern obtained from the two different peripheral sites. The other 196 study neonates had negative blood cultures from both sites. The single episode of early-onset sepsis was caused by Listeria monocytogenes, while all remaining episodes were late-onset with the following organisms: Staphylococcus epidermidis (7), methicillin-resistant Staphylococcus aureus (MRSA) (3), combined MRSA and Candida albicans (2), Candida albicans alone (2), late-onset Group B beta-hemolytic Streptococcus (GBS) (2), Klebsiella pneumoniae (2), Enterococcus fecalis (1), Escherichia coli (1), and Serratia marcescens (1). Since no infant grew organisms from only one of the two sites, the data indicate that the diagnosis of sepsis would have been made correctly in all infants with a single site culture. CONCLUSIONS: Two site blood cultures for the initial evaluation of neonatal sepsis do not have a better yield in pathogen detection. Sepsis in neonates can be detected with no loss of accuracy with a single site blood culture with blood volume of>or=1 ml.

Early high-frequency oscillatory ventilation versus synchronized intermittent mandatory ventilation in very low birth weight infants: a pilot study of two ventilation protocols.

OBJECTIVE: To evaluate the feasibility of conducting a prospective, randomized trial comparing early high-frequency oscillatory ventilation (HFOV) to synchronized intermittent mandatory ventilation (SIMV) in very low birth weight (VLBW) premature infants. This pilot study evaluated two ventilator management protocols to determine how well they could be implemented in a multicenter clinical trial. Although this pilot study was not powered to detect differences in outcome, we also collected outcome data. DESIGN: Prospective, multicenter, randomized pilot study. SETTING: Seven tertiary-level intensive care nurseries with previous experience with both HFOV and flow-triggered SIMV. PATIENTS: Fifty infants weighing 501 to 1200 g, less than 4 hours of age, who had received one dose of surfactant and required ventilation with mean airway pressure > or =6 cm H2O and F(I)O2 > or =0.25, and had an anticipated duration of ventilation greater than 24 hours. INTERVENTIONS: Patients were stratified by birth weight and prenatal steroid status, then randomized to either HFOV or SIMV with tidal volume monitoring. Ventilator management for patients in both study arms was strictly governed by protocols that included optimizing lung inflation and blood gases, weaning strategies, and extubation criteria. MEASUREMENTS: Data were collected using the tools planned for the larger collaborative study. Protocol compliance was closely monitored, with successive changes in the protocol made as necessary to improve clarity and increase compliance. The incidence of major neonatal adverse outcomes was recorded. MAIN RESULTS: Data are presented for 24 HFOV and 24 SIMV infants (two infants, twins, were withdrawn from the study at parent's request). Nineteen of the 24 HFOV infants and 20 of the 24 SIMV infants survived to 36 weeks corrected age. Age at final extubation for survivors was 16+/-16 (mean+/-SD) days for HFOV infants and 24+/-24 days for SIMV infants. At 36 weeks corrected age, 14 of the 19 HFOV survivors were extubated and in room air, whereas 5 required supplemental oxygen. In comparison, 6 of the 20 SIMV survivors were extubated and in room air, whereas 14 required supplemental oxygen. Grade III/IV IVH and/or periventricular leukomalacia occurred in 2 HFOV and 2 SIMV patients. Overall compliance with the ventilator protocols was 82% for the SIMV protocol, and 88% for the HFOV protocol. CONCLUSIONS: The preliminary outcome data supports conducting the large randomized trial, which began in July of 1998. The protocols for the ventilator management of VLBW infants, both with HFOV and with SIMV were easily implemented and consistently followed, and are presented here.

Expanded uses of surfactant therapy.

There are few therapies for which the cumulative evidence of benefit is as much as that for surfactant therapy for RDS in premature infants. Exogenous surfactant therapy does seem to be beneficial for a number of non-RDS disorders. Although there are some trials supporting its use in MAS and ALI-ARDS, there are only a few small prospective, randomized, controlled trials supporting surfactant use in non-RDS disorders. Use of surfactant therapy for any disorder other than RDS must be considered "off the shelf" and experimental. Much work remains to be done to address the role of surfactant therapy in the myriad disorders discussed. Of import for each of the disorders is addressing the optimum type of surfactant to use, and the appropriate dose, method of delivery, and duration of treatment regimens.

Handling the meconium-stained infant.

Clinicians who care for infants in the delivery room or afterward must frequently manage many born through meconium-stained amniotic fluid (MSAF). Approximately 5% of infants born through MSAF develop meconium aspiration syndrome (MAS). This disorder can be severe in nature, with half or more of the affected children needing mechanical ventilation. It is frequently associated with pulmonary air leaks and the presence of persistent pulmonary hypertension. MAS is the most common disorder for which babies may be treated with extracorporeal life support. Various possibilities for preventing MAS exist during labor, parturition, and the first minutes of life. Proposed antenatal therapies include amnioinfusion; intrapartum maneuvers include oropharyngeal suctioning prior to delivery of the babies shoulders; the postnatal intervention of intubation for intratracheal suctioning should be reserved for the non-vigorous meconium-stained infant.

Advances in the treatment of the meconium aspiration syndrome.

Meconium aspiration syndrome (MAS) is a common cause of respiratory distress in neonates. In many affected children, the complex nature of meconium aspiration syndrome contributes to the apparent lack of response to standard therapies. Over the past decade, several new therapies have been suggested to be more effective than "conventional" management in treating meconium aspiration syndrome. These include: anti-inflammatory drugs, medications to counter the effect of prostaglandin-related compounds, high-frequency ventilation, exogenous surfactant, inhaled nitric oxide and liquid ventilation. There are, however, scant evidence-based data to justify routine use of any of those therapies. Additional prospective, well-controlled, randomized trials of diverse therapies are needed to elucidate the optimum management of MAS.

When combined, early bedside head ultrasound and electroencephalography predict abnormal computerized tomography or magnetic resonance brain images obtained after extracorporeal membrane oxygenation treatment.

Definitive neuroimaging of the brain using computerized tomography (CT) or magnetic resonance imaging (MRI) in extracorporeal membrane oxygenation (ECMO)-treated infants must be delayed until after this therapy is completed. Bedside head ultrasound (HUS) and electroencephalography (EEG) studies during ECMO, if highly correlated with later definitive neuroimaging, might be used to affect the acute clinical care and early parental counseling of infants with severe cardiorespiratory failure. One hundred and sixty ECMO-treated patients had both bedside EEG and HUS studies performed during ECMO, as well as a later CT or MRI study prior to hospital discharge. There was a significant difference in CT or MRI findings among patients having normal studies on both the HUS and EEG, compared to those having an abnormality on either the HUS or the EEG, and compared to those having abnormalities on both studies. In ECMO-treated infants, the combination of a normal bedside HUS and an EEG without marked abnormalities is highly predictive of normal post-ECMO CT and MRI neuroimaging studies.

Delivery room management of the apparently vigorous meconium-stained neonate: results of the multicenter, international collaborative trial.

OBJECTIVE: Disagreement exists concerning the appropriate delivery room management of the airway of vigorous meconium-stained infants. Some suggest a universal approach to intubation and suctioning of the airway in all such neonates, whereas others advocate a selective approach. We performed this investigation: 1) to assess whether intubation and suctioning of apparently vigorous, meconium-stained neonates would reduce the incidence of meconium aspiration syndrome (MAS); and 2) to determine the frequency of complications from delivery room intubation and suctioning of such infants. METHODS: Inclusion criteria included: 1) gestational age >/=37 weeks; 2) birth through meconium-stained amniotic fluid of any consistency; and 3) apparent vigor immediately after birth. Subjects were randomized to be intubated and suctioned (INT) or to expectant management (EXP). Primary outcome measures included: 1) the incidence of respiratory distress, including MAS, and 2) the incidence of complications from intubation. RESULTS: A total of 2094 neonates were enrolled from 12 participating centers (1051 INT and 1043 EXP). Meconium-stained amniotic fluid consistency was similar in both groups. Of the 149 (7.1%) infants that subsequently demonstrated respiratory distress, 62 (3.0%) had MAS and 87 (4.2%) had findings attributed to other disorders. There were no significant differences between groups in the occurrence of MAS (INT = 3.2%; EXP = 2.7%) or in the development of other respiratory disorders (INT = 3.8%; EXP = 4.5%). Of 1098 successfully intubated infants, 42 (3.8%) had a total of 51 complications of the procedure. In all cases, the complications were mild and transient in nature. CONCLUSIONS: Compared with expectant management, intubation and suctioning of the apparently vigorous meconium-stained infant does not result in a decreased incidence of MAS or other respiratory disorders. Complications of intubation are infrequent and short-lived.

Bronchopulmonary segmental lavage with Surfaxin (KL(4)-surfactant) for acute respiratory distress syndrome.

We performed a trial to assess the safety and tolerability of sequential bronchopulmonary segmental lavage with a dilute synthetic surfactant (Surfaxin) in 12 adults with ARDS. Patients received one of three dosing regimens in which aliquots of Surfaxin were administered via a wedged bronchoscope to each of the 19 bronchopulmonary segments. Suctioning was performed 10-30 s after instillation of individual aliquots. Group 1 patients (n = 3) received one 30-ml aliquot of a 2.5-mg/ml concentration of Surfaxin in each segment, followed by a second 30-ml aliquot with a 10-mg/ml concentration. Group 2 patients (n = 4) received two 30-ml aliquots of the 2.5-mg/ml concentration followed by a third lavage with the 10-mg/ml concentration. Group 3 patients (n = 5) received therapy identical to that received by patients in Group 2 and were eligible for repeat dosing 6 to 24 h later. All patients tolerated the procedure. There were no serious adverse experiences ascribed to either the procedure or the surfactant. In the 96 h after treatment initiation, FI(O(2)) decreased from 0.80 to 0.52 and PEEP decreased from 10.3 to 7.6 cm H(2)O. Bronchoscopic "cleansing" of the lungs with dilute Surfaxin may offer a safe and feasible approach to improving outcomes in patients with ARDS. Wiswell TE, Smith RM, Katz LB, Mastroianni L, Wong DY, Willms D, Heard S, Wilson M, Hite RD, Anzueto A, Revak SD, Cochrane CG. Bronchopulmonary segmental lavage with Surfaxin (KL(4)-surfactant) for acute respiratory distress syndrome.

Management of meconium-stained amniotic fluid.

Meconium staining of the amniotic fluid will always be a common problem. Although several therapies may be of benefit in preventing MAS, most require further rigorous scientific investigation to assess their potential in preventing this disorder.

The possible role of magnesium in protection of premature infants from neurological syndromes and visual impairments and a review of survival of magnesium-exposed premature infants.

The survival rate of very preterm, low birth weight infants (weighing less than 1500 g) is 85 per cent in the USA and is ever increasing, while 42 to 75 per cent of extremely premature infants (weighing 751-1000 g) survive. Of great concern is the lack of consistent decrease in neurological syndromes and associated visual impairments. Because of short gestations, these infants have not had time to accrue up to 80 per cent of magnesium normally present at term. These very preterm infants are at highest risk for cerebral hypoxia/ischemia (H/I), intracranial hemorrhage (ICH), periventricular leukomalacia (PVL) or cystic PVL (CPVL), and possible sequelae, cerebral palsy (CP) and mental retardation (MR). These syndromes are associated with damage to optic structures and the visual pathways which traverse the brain. Visual defects are common in surviving preterm infants. Increased levels of harmful neurochemical mediators that have been reported in these conditions include oxygen free radicals, excitatory amino acids, tumor necrosis factor-alpha (TNF-a), and thromboxane A2 (TXA2) which are aggravated in magnesium deficiency and may be ameliorated by magnesium. We review the published data concerning the effects of prenatal magnesium supplementation on ICH, CPVL, CP and MR and available reports concerning survival. Further considerations on the safety and efficacy of magnesium sulphate administration given prenatally to the preterm neonate await the outcome of three trials that are continuing for more than a year on three continents.

Meconium-stained amniotic fluid and the meconium aspiration syndrome. An update.

Over the past 5 years, increasing understanding about the pathophysiology of meconium-stained amniotic fluid (MSAF) and the meconium aspiration syndrome (MAS) has occurred. Many new therapies are being used in an attempt to prevent MAS and to treat the disorder. The authors review the current status of knowledge concerning the MSAF and MAS and management of these entities.

Mainstream end-tidal carbon dioxide monitoring in the neonatal intensive care unit.

BACKGROUND: Continuous noninvasive monitoring of arterial carbon dioxide (CO2) in neonatal intensive care unit (NICU) patients would help clinicians avoid complications of hypocarbia and hypercarbia. End-tidal CO2 monitoring has not been used in this population to date, but recent technical advances and the introduction of surfactant therapy, which improves ventilation-perfusion matching, might improve the clinical utility of end-tidal monitoring. OBJECTIVE: To determine the accuracy and precision of end-tidal CO2 monitoring in NICU patients. DESIGN: Nonrandomized recording of simultaneous end-tidal and arterial CO2 pairs. SETTING: Two university NICUs. PATIENTS: Forty-five newborn infants receiving mechanical ventilation who had indwelling arterial access, and a predefined subsample of infants who were <1000 g birth weight, <8 days of age, and who received surfactant therapy (extremely low birth weight -ELBW- <8). OUTCOME MEASURES: The correlation coefficient, degree of bias, and 95% confidence interval were determined for both the overall population and the ELBW <8 subgroup. Those factors which significantly influenced the bias were identified. The ability of the end-tidal monitor to alert the clinician to instances of hypocarbia or hypercarbia was determined. RESULTS: There were 411 end-tidal/arterial pairs analyzed from 45 patients. The correlation coefficient was 0.833 and the bias was -6. 9 mm Hg (95% confidence interval, +/-11.5 mm Hg). The results did not differ markedly in the ELBW <8 infants. Measures of the degree of lung disease, the ventilation index and the oxygenation index, had small influences on the degree of bias. This type of capnometry identified 91% of the instances when the arterial CO2 pressure was between 34 and 54 mm Hg using an end-tidal range of 29 to 45 mm Hg. End-tidal values outside this range had a 63% accuracy in predicting hypocarbia or hypercarbia. CONCLUSION: End-tidal CO2 monitoring in NICU patients is as accurate as capillary or transcutaneous monitoring but less precise than the latter. It may be useful for trending or for screening patients for abnormal arterial CO2 values.

Volutrauma, PaCO2 levels, and neurodevelopmental sequelae following assisted ventilation.

Today it is essential that we define care practices in neonatology that not only increase survival but also produce optimal pulmonary and neurodevelopmental outcomes for our patients. Assisted ventilatory care continues to be influential at all three levels. In this article, the authors discuss current understanding of the possible mechanisms for pulmonary and neurologic injury, or benefits associated with ventilation at both low and high PaCO2 levels, as well as evidence for neurodevelopmental sequelae with various ventilator strategies.

Contemporary controversies in the management of congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) has remained the most frustrating of the major birth defects to manage successfully. Despite the earlier detection of severe diaphragmatic defects by prenatal ultrasound, and the early recognition of CDH as a cause for respiratory distress presenting at birth, current mortality has improved little from the original series presented in 1940 by Ladd and Gross. This article discusses the difficulty in defining population with congenital diaphragmatic hernia, current controversies in the medical and surgical management of these patients, appropriate timing and usage of ECMO, a review of current, experimental therapies, and short-term and long-term outcomes of these patients.