Combining hand techniques with electric pumping increases the caloric content of milk in mothers of preterm infants.

OBJECTIVE: We previously reported that preterm mothers' milk production can exceed levels of term mothers by using early hand expression and hands-on pumping (HOP) with the highest production (955 ml per day) in frequent users of hand expression. In this study, we compared milk composition between mothers stratified by early hand expression frequency. STUDY DESIGN: A total of 67 mothers of infants <31 weeks gestation were instructed on hand expression and HOP. Subjects submitted expression records and 1-ml samples from each pumping session over 24 h once weekly for 8 weeks. RESULT: 78% (52/67) of mothers completed the study. But for Week 1, no compositional differences (despite production differences) were noted between the three groups. Protein and lactose tracked reported norms, but fat and energy of mature milk (Weeks 2-8) exceeded norms, 62.5 g l(-1) per fat and 892.7 cal l(-1) (26.4 cal oz(-1)), respectively. CONCLUSION: Mothers combining manual techniques with pumping express high levels of fat-rich, calorie-dense milk, unrelated to production differences.

Improved outcomes with a standardized feeding protocol for very low birth weight infants.

OBJECTIVE: The objective of this study was to evaluate the impact of a standardized enteral feeding protocol for very low birth weight (VLBW) infants on nutritional, clinical and growth outcomes. STUDY DESIGN: Retrospective analysis of VLBW cohorts 9 months before and after initiation of a standardized feeding protocol consisting of 6-8 days of trophic feedings, followed by an increase of 20 ml/kg/day. The primary outcome was days to reach full enteral feeds defined as 160 ml/kg/day. Secondary outcomes included rates of necrotizing enterocolitis and culture-proven sepsis, days of parenteral nutrition and growth end points. RESULT: Data were analyzed on 147 VLBW infants who received enteral feedings, 83 before ('Before') and 64 subsequent to ('After') feeding protocol initiation. Extremely low birth weight (ELBW) infants in the After group attained enteral volumes of 120 ml/kg/day (43.9 days Before vs 32.8 days After, P=0.02) and 160 ml/kg/day (48.5 days Before vs 35.8 days After, P=0.02) significantly faster and received significantly fewer days of parenteral nutrition (46.2 days Before vs 31.3 days After, P=0.01). Necrotizing enterocolitis decreased in the After group among VLBW (15/83, 18% Before vs 2/64, 3% After, P=0.005) and ELBW infants (11/31, 35% Before vs 2/26, 8% After, P=0.01). Late-onset sepsis decreased significantly in the After group (26/83, 31% Before vs 6/64, 9% After, P=0.001). Excluding those with weight <3rd percentile at birth, the proportion with weight <3rd percentile at discharge decreased significantly after protocol initiation (35% Before vs 17% After, P=0.03). CONCLUSION: These data suggest that implementation of a standardized feeding protocol for VLBW infants results in earlier successful enteral feeding without increased rates of major morbidities.

Combining hand techniques with electric pumping increases milk production in mothers of preterm infants.

OBJECTIVE: Pump-dependent mothers of preterm infants commonly experience insufficient production. We observed additional milk could be expressed following pumping using hand techniques. We explored the effect on production of hand expression of colostrum and hands-on pumping (HOP) of mature milk. STUDY DESIGN: A total of 67 mothers of infants <31 weeks gestation were enrolled and instructed on pumping, hand expression of colostrum and HOP. Expression records for 8 weeks and medical records were used to assess production variables. RESULT: Seventy-eight percent of the mothers completed the study. Mean daily volumes (MDV) rose to 820 ml per day by week 8 and 955 ml per day in mothers who hand expressed >5 per day in the first 3 days. Week 2 and/or week 8 MDV related to hand expression (P<0.005), maternal age, gestational age, pumping frequency, duration, longest interval between pumpings and HOP (P<0.003). Mothers taught HOP increased MDV (48%) despite pumping less. CONCLUSION: Mothers of preterm infants may avoid insufficient production by combining hand techniques with pumping.

A quality improvement project to improve admission temperatures in very low birth weight infants.

OBJECTIVE: To review the results of a quality improvement (QI) project to improve admission temperatures of very low birth weight inborn infants. STUDY DESIGN: The neonatal intensive care unit at Lucile Packard Children's Hospital underwent a QI project to address hypothermic preterm newborns by staff education and implementing processes such as polyethylene wraps and chemical warming mattresses. We performed retrospective chart review of all inborn infants with birth weight <1500 g during the 18 months prior to (n=134) and 15 months after (n=170) the implementation period. Temperatures were compared between periods. Multivariable logistic regression was used to account for potential confounding variables. We compared mortality rates and grade 3 or 4 intraventricular hemorrhage rates between periods. RESULT: The mean temperature rose from 35.4 to 36.2 degrees C (P<0.0001) after the QI project. The improvement was consistent and persisted over a 15-month period. After risk adjustment, the strongest predictor of hypothermia was being born in the period before implementation of the QI project (odds ratio 8.12, 95% confidence interval 4.63, 14.22). Although cesarean delivery was a strong risk factor for hypothermia prior to the project, it was no longer significant after the project. There was no significant difference in death or intraventricular hemorrhage detected between periods. CONCLUSION: There was a significant improvement in admission temperatures after a QI project, which persisted beyond the initial implementation period. Although there was no difference in mortality or intraventricular hemorrhage rates, we did not have sufficient power to detect small differences in these outcomes.

Venoarterial versus venovenous extracorporeal membrane oxygenation in congenital diaphragmatic hernia: the Extracorporeal Life Support Organization Registry, 1990-1999.

BACKGROUND/PURPOSE: Venoarterial (VA) extracorporeal membrane oxygenation (ECMO) traditionally has been the mode of support used in congenital diaphragmatic hernia (CDH). A few studies report success using venovenous (VV) ECMO. The purpose of this study is to compare outcomes in CDH patients treated with VA and VV. METHODS: The authors queried the Extracorporeal Life Support Organization Registry for newborns with CDH treated with ECMO from January 1, 1990 through December 31, 1999. They analyzed the pre-ECMO data, ECMO course, and complications. RESULTS: VA was utilized in 2,257 (86%) and VV in 371 (14%) patients. The pre-ECMO status was similar, with greater use of nitric oxide, surfactant, and pressors in VV. Survival rate was similar (58.4% for VV and 52.2% for VA, P =.057). VA was associated with more seizures (12.3% v 6.7%, P =.0024) and cerebral infarction (10.5% v 6.7%, P =.03). Sixty-four treatments were converted from VV to VA (VV-->VA). Survival rate in VV-->VA was not significantly different than VA (43.8% v 52.2%, respectively; P =.23). VV-->VA and VA patients had similar neurologic complications. CONCLUSIONS: CDH patients treated with VV and VA have similar survival rates. VA had more neurologic complications. The authors identified no disadvantage to the use of VV as an initial mode of ECMO for CDH, although some infants may need conversion to VA.

Secondary infection presenting as recurrent pulmonary hypertension.

Primary infection in the neonate, especially group B streptococcal infection, has long been recognized as a cause of persistent pulmonary hypertension of the newborn (PPHN), sometimes requiring treatment with inhaled nitric oxide (iNO) and extracorporeal membrane oxygenation (ECMO). However, secondary nosocomial infections in the neonatal period have not been widely reported as a cause of severe recurrent pulmonary hypertension (PHTN). We now present two cases of secondary infection in the neonate leading to significant PHTN. In both cases, the infants presented with PPHN soon after birth, requiring transfer to a level 3 neonatal intensive care unit and treatment with high-frequency oscillatory ventilation and iNO. After successful resolution of the initial PPHN, including extubation to nasal cannula, both infants developed signs of severe recurrent PHTN, leading to reintubation, high-frequency oscillatory ventilation and iNO therapy, and consideration of ECMO. In both cases, blood cultures taken at the time of recurrence of PHTN returned positive, one for Staphylococcus epidermidis, the other for methicillin-resistant Staphylococcus aureus. These unusual cases present the possibility of severe recurrent PHTN requiring iNO or ECMO in the setting of secondary infection. We speculate that these infants, although extubated after their first episodes of PHTN, were at risk for recurrence of PHTN due to continued pulmonary vascular reactivity.

Sonography, CT, and MR imaging: a prospective comparison of neonates with suspected intracranial ischemia and hemorrhage.

BACKGROUND AND PURPOSE: Sonography, CT, and MR imaging are commonly used to screen for neonatal intracranial ischemia and hemorrhage, yet few studies have attempted to determine which imaging technique is best suited for this purpose. The goals of this study were to compare sonography with CT and MR imaging prospectively for the detection of intracranial ischemia or hemorrhage and to determine the prognostic value(s) of neuroimaging in neonates suspected of having hypoxic-ischemic injury (HII). METHODS: Forty-seven neonates underwent CT (n = 26) or MR imaging (n = 24) or both (n = 3) within the first month of life for suspected HII. Sonography was performed according to research protocol within an average of 14.4 +/- 9.6 hours of CT or MR imaging. A kappa analysis of interobserver agreement was conducted using three independent observers. Infants underwent neurodevelopmental assessment at ages 2 months (n = 47) and 2 years (n = 26). RESULTS: CT and MR imaging had significantly higher interobserver agreement (P < .001) for cortical HII and germinal matrix hemorrhage (GMH) (Grades I and II) compared with sonography. MR imaging and CT revealed 25 instances of HII compared with 13 identified by sonography. MR imaging and CT also revealed 10 instances of intraparenchymal hemorrhage (>1 cm, including Grade IV GMH) compared with sonography, which depicted five. The negative predictive values of neuroimaging, irrespective of technique used, were 53.3% and 58.8% at the 2-month and 2-year follow-up examinations, respectively. CONCLUSION: CT and MR imaging have significantly better interobserver agreement for cortical HII and GMH/intraventricular hemorrhage and can reveal more instances of intraparenchymal hemorrhage compared with sonography. The absence of neuroimaging findings on sonograms, CT scans, or MR images does not rule out later neurologic dysfunction.

Decreased use of neonatal extracorporeal membrane oxygenation (ECMO): how new treatment modalities have affected ECMO utilization.

OBJECTIVE: Over the last decade, several new therapies, including high-frequency oscillatory ventilation (HFOV), exogenous surfactant therapy, and inhaled nitric oxide (iNO), have become available for the treatment of neonatal hypoxemic respiratory failure. The purpose of this retrospective study was to ascertain to what extent these modalities have impacted the use of neonatal extracorporeal membrane oxygenation (ECMO) at our institution. METHODS: Patients from 2 time periods were evaluated: May 1, 1993 to November 1, 1994 (group 1) and May 1, 1996 to November 1, 1997 (group 2). During the first time period (group 1), HFOV was not consistently used; beractant (Survanta) use for meconium aspiration syndrome (MAS), persistent pulmonary hypertension of the newborn (PPHN), and pneumonia was under investigation; and iNO was not yet available. During the second time period (group 2), HFOV and beractant treatment were considered to be standard therapies, and iNO was available to patients with oxygenation index (OI) >/=25 x 2 at least 30 minutes apart, or on compassionate use basis. Patients were included in the data collection if they met the following entry criteria: 1) OI >15 x 1 within the first 72 hours of admission; 2) EGA >/=35 weeks; 3) diagnosis of MAS, PPHN or sepsis/pneumonia; 4) <5 days of age on admission; and 5) no congenital heart disease, diaphragmatic hernia, or lethal congenital anomaly. RESULTS: Of the 49 patient in group 1, 21 (42.8%) required ECMO therapy. Of these ECMO patients, 14 (66.6%) had received diagnoses of MAS or PPHN. Only 3 of the patients that went on to ECMO received beractant before the initiation of bypass (14.3%). All ECMO patients in group 1 would have met criteria for iNO had it been available. Of all patients in group 1, 18 (36.7%) were treated with HFOV, and 13 (26.5%) received beractant. Of the 47 patients in group 2, only 13 (27.7%) required ECMO therapy (compared with group 1). Of these ECMO patients, only 5 (38.5%) had diagnoses of MAS or PPHN, with the majority of patients (61.5%) requiring ECMO for sepsis/pneumonia, with significant cardiovascular compromise. Only 5 of these ECMO patients, all outborn, did not receive iNO before cannulation because of the severity of their clinical status on admission. Of all patients in group 2, 41 (87.2%) were treated with HFOV (compared with group 1), 42 (89.3%) received beractant (compared with group 1), and 18 (44.7%) received iNO. CONCLUSIONS: The results indicate that ECMO was used less frequently when HFOV, beractant and iNO was more commonly used. The differences in treatment modalities used and subsequent use of ECMO were statistically significant. We speculate that, in this patient population, the diagnostic composition of neonatal ECMO patients has changed over time.

Bilirubin toxicity and differentiation of cultured astrocytes.

OBJECTIVE: To study the toxicity of bilirubin in primary cultures of newborn rat cerebral cortical astrocytes. STUDY DESIGN: Primary cultures of newborn rat astrocytes were incubated at bilirubin concentrations of 0, 1, 5, 10, 25, 50, 100, 200, and 2000 microM, at a bilirubin:albumin molar ratio of 1.7. Bilirubin toxicity was determined by changes in cellular morphology, trypan blue staining, and lactate dehydrogenase (LDH) release into the culture medium at various times of incubation. To determine if differentiation of astrocytes affects bilirubin toxicity, cultures were treated with dibutyryl cyclic adenosine monophosphate. RESULTS: All three indices of toxicity showed a bilirubin concentration dependence. LDH release in experimental cultures was significantly elevated (p < 0.05) above that of control cultures by 24 hours at bilirubin concentrations of > or = 100 microM. The absolute amount of LDH release differed significantly between the 200 and 2000 microM cultures from 1.5 to 24 hours, after which duration of exposure appeared to take over and all cultures approached maximum. LDH release for the lower concentrations all reached maximum by 120 hours, except for the 1 microM cultures, which showed no significant elevation above control throughout the study period. At 100 and 200 microM bilirubin, LDH release by untreated cells was significantly higher (p < 0.05) than release by treated cells by 36 hours. CONCLUSION: Undifferentiated astrocytes appeared to be more sensitive to bilirubin toxicity, which may correlate with the greater susceptibility of newborns to kernicteric injury. Studies with primary astrocyte culture may provide insight into how bilirubin sensitivity changes with brain development as well as the cellular and biochemical mechanisms of bilirubin encephalopathy.

Strategy for lipid suppression in lactate imaging using STIR-DQCT: a study of hypoxic-ischemic brain injury.

In vivo lactate detection using gradient enhanced double quantum coherence transfer (DQCT) was significantly improved by addition of short-time-inversion-recovery (STIR). Phantom studies demonstrated lipid suppression down to the background noise level with 33% loss of lactate signal. In vivo studies using a rabbit model of hypoxic and unilateral-ischemic brain injury showed reduction down to 29 +/- 11% in lipids with inversion times between 140 and 170 ms. Lactate signals on the ischemic side were 51 +/- 53% higher than the nonischemic side at the peak of hypoxia. STIR-DQCT can be a useful robust method of obtaining metabolic maps of lactate in vivo.

Congenital diaphragmatic hernia associated with aortic coarctation.

Congenital diaphragmatic hernia (CDH) may be associated with other anomalies, most frequently cardiovascular in nature. Despite fetal echocardiography, diagnosis of an accompanying cardiac malformation often is not made until after birth and sometimes not until after extracorporeal membrane oxygenation (ECMO) has been instituted. Aortic coarctation associated with CDH may occur as an isolated, surgically correctable malformation or it may be a component of the usually fatal left heart "hypoplasia" or "smallness" syndrome. The authors present two cases of aortic coarctation associated with CDH requiring ECMO that illustrate the management challenges of these coincident diagnosis. In one case, the accompanying coarctation was suspected and required precannulation angiography for confirmation, whereas in the other case, the diagnosis of coarctation was not made until after ECMO cannulation. Depending on its anatomic location and severity, an aortic coarctation associated with life-threatening CDH may limit the physiological efficacy of venoarterial ECMO. Furthermore, arterial cannulation for extracorporeal support requires that flow through the remaining carotid artery be maintained during aortic reconstruction, which may prove difficult for lesions best treated by subclavian flap angioplasty. When the diagnosis of coincident aortic coarctation and CDH is suspected or proven before institution of extracorporeal support, serious consideration should be given to venovenous bypass, because this may provide better postductal oxygenation and facilitate aortic repair with the option of left carotid artery inflow occlusion.

Hemopericardium from coronary artery laceration complicating extracorporeal membrane oxygenation.

OBJECTIVE: We report the clinical course and successful surgical treatment of hemopericardium resulting from coronary artery (CA) laceration in two patients with congenital diaphragmatic hernia (CDH) undergoing extracorporeal membrane oxygenation (ECMO) bypass. STUDY DESIGN: Retrospective case review. RESULTS: Two neonates with CDH had needle aspiration for either pneumothorax or pericardial effusion before initiation of ECMO. While on bypass, progressive hemopericardium led to narrow pulse pressure and decreased venous return that limited bypass flow. Widened cardiac silhouette on chest radiographs suggested hemopericardium; echocardiography was confirmatory in one case. The underlying diagnosis of CA laceration was made during pericardiotomy and treated with surgical patching. CONCLUSIONS: Pre-ECMO history of cardiothoracic needle aspiration is important because complications such as hemothorax or hemopericardium may arise once ECMO bypass is initiated. Inadvertent CA laceration may lead to acute hemopericardium, compromising venous drainage. However, CA laceration can be successfully repaired while the patient is on bypass.

Response of premature infants with severe respiratory failure to inhaled nitric oxide. Preemie NO Collaborative Group.

Elevated pulmonary vascular resistance is seen in premature infants with severe respiratory distress syndrome (RDS). Inhaled nitric oxide (NO) has been shown to decrease pulmonary vascular resistance and to improve oxygenation in some patients with respiratory failure. The purpose of this study was to determine whether premature infants with severe RDS would respond to inhaled NO with an improvement in oxygenation. Eleven premature infants (mean gestational age 29.8 weeks) with severe respiratory failure caused by RDS were treated with NO in four concentrations [1, 5, 10, 20 parts per million (ppm) NO] and with placebo (0 ppm NO). Arterial blood gas measurements were drawn immediately before and at the end of each of the 15-minute treatments and were used to determine the arterial/alveolar oxygen ratio (PaO2/PAO2). Ten of the 11 infants had a greater than 25% increase in PaO2/PAO2. Five of the 11 had a greater than 50% increase in PaO2/PAO2. Despite normal cranial ultrasound imaging prior to NO, 3 infants had intracranial hemorrhage (ICH) noted on their first ultrasound scan after this brief period of NO treatment, and 4 additional infants developed ICH later during their hospitalization. No infant had significant elevations of methemoglobin concentrations after the total 60-minute exposure to NO. NO may be an effective method of improving oxygenation in infants with severe RDS. The disturbing incidence of ICH in this small group of infants needs to be carefully evaluated before considering routine use or NO for preterm infants.

Nitrovasodilator therapy for severe respiratory distress syndrome.

Improved gas exchange in infants with severe respiratory distress syndrome has been reported in association with infusion of nitroprusside and during inhalation of nitric oxide. To evaluate the association between nitrovasodilator therapy and clinical improvement in premature neonates with severe respiratory distress syndrome, we reviewed the courses of 22 infants with severe respiratory distress syndrome who were treated with sodium nitroprusside for at least 24 hours. These infants had birth weights of 2049 +/- 828 gm (range 720 to 3430 gm), gestational ages of 32.5 +/- 3.5 weeks (range 25 to 38 weeks), high ventilator settings before treatment (FIO2 of 100%, peak inspiratory pressures of 37.8 +/- 6.1 cm H2O [range 30 to 50 cm H2O], and mean airway pressures of 18.0 +/- 3.3 cm H2O [range 12.3 to 26 cm H2O]), and low pretreatment PaO2 of 49.3 +/- 9.4 mm Hg (range 27 to 69 mm Hg). Baseline oxygenation indexes were 39.4 +/- 12.1 (range 18.6 to 66.7). Nitroprusside infusion was temporally associated with increased PaO2, decreased PaCO2, and reduced oxygenation index. Potentially beneficial changes were inconsistent in infants with pulmonary interstitial emphysema and were greatest in infants treated with end-expiratory pressures of at least 4 cm H2O. These observations provide a basis for the hypothesis that nitrovasodilator therapy produces improvement in gas exchange in premature infants with severe respiratory distress syndrome.

A model for detecting early metabolic changes in neonatal asphyxia by 1H-MRS.

In newborn rabbits, the early cerebral metabolic changes caused by hypoxic-ischemic (H-I) insult was examined by using volume localized 1H-MRS (STEAM). Partial ischemia was caused by unilateral carotid artery ligation, and hypoxia was induced by 10% oxygen inspiration for 150 minutes. Lactate immediately increased after hypoxia induction and almost disappeared 120 to 150 minutes after removal of hypoxia in both H-I and hypoxia-only experiments. Lactate production correlated well with decrease of the blood oxygen saturation. More lactate was produced on ischemic side 50 minutes post-hypoxia induction in H-I study. Ischemia alone did not cause any significant lactate production. Lactate caused by hypoxia can be dynamically monitored by localized 1H-MRS. Existence of regional ischemia can induce greater anaerobic glycolysis and may affect the pattern of brain injury under hypoxia. 1H-MRS is a sensitive tool to detect the acute metabolic change caused by H-I insult.

Lobar lung transplantation as a treatment for congenital diaphragmatic hernia.

The mortality rate for infants severely affected with congenital diaphragmatic hernia (CDH) remains high despite significant advances in surgical and neonatal intensive care including delayed repair and extracorporeal membrane oxygenation (ECMO). Because of the increasingly successful experience with single-lung transplantation in adults; this approach has been suggested as a potential treatment for CDH infants with unsalvageable pulmonary hypoplasia. The authors report on a newborn female infant who was the product of a pregnancy complicated by polyhydramnios. At birth, she was found to have a right-sided CDH and initially was treated with preoperative ECMO, followed by delayed surgical repair. Despite the CDH repair and apparent resolution of pulmonary hypertension, the infant's condition deteriorated gradually after decannulation, and escalating ventilator settings were required as well as neuromuscular paralysis and pressor support because of progressive hypoxemia and hypercarbia. A lung transplant was performed 8 days after decannulation, using the right lung obtained from a 6-week-old donor. The right middle lobe was excised because of the size discrepancy between the donor and recipient. After transplantation, the patient was found to have duodenal stenosis and gastroesophageal reflux, which required duodenoduodenostomy and fundoplication. The patient was discharged from the hospital 90 days posttransplantation, at 3 1/2 months of age. Currently she is 24 months old and doing well except for poor growth. This case shows the feasibility of single-lung transplantation for infants with CDH, and the potential use of ECMO as a temporary bridge to transplantation. Lobar lung transplantation allowed for less stringent size constraints for the donor lung.

Intracranial abnormalities and neurodevelopmental status after venovenous extracorporeal membrane oxygenation.

Computed tomography scans of the head and early neurodevelopmental assessment (Bayley Scales of Infant development) were recorded for 24 surviving infants who received venovenous extracorporeal membrane oxygenation and were compared with those of infants treated with venoarterial bypass matched by diagnosis and oxygenation index before extracorporeal membrane oxygenation. A comparable neuroradiographic and early neurodevelopmental outcome was documented for survivors of venoarterial and venovenous extracorporeal membrane oxygenation.