Smeeta Sardesai

Lung protective ventilatory strategies in very low birth weight infants.

Respiratory distress syndrome (RDS) is the most common respiratory diagnosis in preterm infants. Surfactant therapy and mechanical ventilation using conventional or high-frequency ventilation have been the standard of care in the management of RDS. Bronchopulmonary dysplasia (BPD) continues to remain as a major morbidity in very low birth weight infants despite these treatments. There is no significant difference in pulmonary outcome when an optimal lung volume strategy is used with conventional or high-frequency ventilation. Lung injury is directly related to the duration of invasive ventilation via the endotracheal tube. Studies using noninvasive ventilation, such as nasal continuous positive airway pressure and noninvasive positive pressure ventilation, have shown to decrease postextubation failures as well as a trend toward reduced risk of BPD. Lung protective ventilatory strategy may involve noninvasive ventilation as a primary therapy or following surfactant administration in very preterm infants with RDS. Initial steps in the management of preterm infants may also include sustained inflation to establish functional residual capacity, followed by noninvasive ventilation to minimize lung injury and subsequent development of BPD.

Iatrogenic skin injury in the neonatal intensive care unit

Although neonatal care has become more and more meticulous with significant changes in technology in the neonatal intensive care unit (NICU) in the past 50 years, iatrogenic cutaneous injuries continue to occur. Although the incidence of severe injuries is decreasing because the more difficult procedures are being replaced by improved techniques, skin injuries have not yet been completely eliminated. However, the nature and causes of cutaneous injuries have changed, and the injuries are frequent but generally minor. The major risk factors are low birth weight, gestational age, length of stay, a central venous line, mechanical ventilation, and support with continuous positive airway pressure. The rate of iatrogenic events is about 57% at gestational ages of 24–27 weeks, compared with 3% at term. There are no current comprehensive reviews of iatrogenic cutaneous injury. The purpose of this review is to describe the iatrogenic cutaneous injuries that may occur in the newborns as a consequence of perinatal and postnatal medical procedures. With increased survival of extremely-low-birth-weight (ELBW) infants and changing modes of management in the NICU, neonatologists must make every effort to recognize injuries and prevent their occurrence in the NICU.

Cardiovascular Effects of Low-Dose Dexamethasone in Very Low Birth Weight Neonates with Refractory Hypotension

Background: Administration of hydrocortisone and relatively high doses of dexamethasone increase blood pressure in volume- and pressor-resistant hypotensive preterm infants. However, little is known about the temporal relationship of dexamethasone administration and the improvement in blood pressure and the weaning of pressors/inotropes. Furthermore, there are no sufficient data available on whether a smaller dose of dexamethasone would also be effective in treating refractory hypotension. Objective: To study the cardiovascular responses to low-dose dexamethasone in very low birth weight neonates with volume- and pressor-resistant hypotension. Methods: Retrospective database review. Twenty-four preterm neonates (gestational age 26 (23–34) weeks; birth weight 801 (457–1,180) g; postnatal age 2 (1–24) days, medians (ranges)) who remained hypotensive despite volume administration and combined dopamine and dobutamine treatment at ≧30 µg/kg/min received dexamethasone 0.1 mg/kg followed by 0.05 mg/kg intravenously every 12 h for 5 additional doses if still on pressors ≧8 µg/kg/min. Results: Two hours after the first dose of dexamethasone the mean blood pressure increased from 30 ± 5 to 34 ± 6 mm Hg (p < 0.001) and remained elevated at 4, 6, 12, and 24 h after treatment was started (p < 0.001). Six hours after the initial dose of dexamethasone the pressor/inotrope requirement decreased from 34 ± 9 to 24 ± 13 µg/kg/min (p = 0.001) and continued to decrease at 12 and 24 h (p < 0.001). Urine output also increased significantly during the first 6 h after dexamethasone (p < 0.001). Conclusions: Low-dose dexamethasone rapidly increases blood pressure and decreases pressor requirements in very low birth weight neonates with volume- and pressor-resistant hypotension.

Constitutive IL-10 expression by lung inflammatory cells and risk for bronchopulmonary dysplasia.

Expression of IL-10 is decreased in lungs of preterm infants. We determined the constitutive and lipopolysaccharide (LPS)-induced IL-10 synthesis by lung inflammatory cells from preterm and term infants and examined their relationship to gestational age and/or incidence of bronchopulmonary dysplasia (BPD). A total of 37 infants; preterm neonates at gestational ages of 23–27 wk (group 1); 28–34 wk (group 2), and four full-term infants with meconium aspiration (group 3) were enrolled. One sample of lung inflammatory cells, obtained during postnatal d 1–3, and another during postnatal d 4–7 were cultured in vitro in presence or absence of 100 μg/mL of LPS. Secreted IL-10 was measured by ELISA. A positive relationship was found between gestational age and LPS-induced, but not constitutive IL-10 production within 1–3 d of life; group 1 on d 1–3 had a significant number of IL-10 nonresponders compared with group 2. All term neonates in group 3 had positive LPS-induced IL-10 response. Thus, in utero maturation of IL-10 gene expression is due to acquisition of inducibility. In contrast, constitutive IL-10 production within d 1–3 of life correlated with, and predicted the incidence of BPD in the highly vulnerable very premature infants.

Congenital Midgut Volvulus Associated with Fetal Anemia

Congenital volvulus is a life-threatening condition, both for the fetus and for the newborn. A volvulus is a twist of small bowel loops or a proximal part of the colon around the mesenteric artery or its branches. The potential consequences of volvulus are ileus and necrosis of the intestinal wall. Prenatal diagnosis of midgut volvulus is difficult. It should be suspected antenatally when polyhydramnios, intestinal dilatation, ascites and/or signs of fetal anemia are present on ultrasound assessment. We report a case of a congenital midgut volvulus associated with fetal anemia. The fetal ultrasound performed at 32 weeks’ gestation showed a polyhydramnios, hydrothorax, thick ascites accumulation around the liver and the suspicion of a dilated bowel loop. Additionally, Doppler examination showed an increased value of peak systolic velocity in the middle cerebral artery. Cordocentesis confirmed significant fetal anemia. At 34 weeks, because of the suspicion of idiopathic meconium ileus and secondary anemia, a Cesarean section was performed after the administration of steroids. During the laparatomy, performed postnatally, a midgut volvulus was diagnosed. The affected portion of the ileum was resected and end-to-end anastomosis performed. An antenatal diagnosis of midgut volvulus should be considered when signs of fetal anemia, including an increased value of peak systolic velocity in the middle cerebral artery, are present with polyhydramnios, fetal ascites, dilated bowel loops on antenatal ultrasound. An assessment of the fetal hemodynamic status should be a part of the ultrasound assessment for patients with nonspecific fetal bowel pathologies, including congenital volvulus.

Evolution of surfactant therapy for respiratory distress syndrome: past, present, and future

Respiratory distress syndrome (RDS) due to surfactant deficiency is the most common cause of respiratory failure in preterm infants. Tremendous progress has been made since the original description that surfactant deficiency is the major cause of RDS. Surfactant therapy has been extensively studied in preterm infants and has been shown to significantly decrease air leaks and neonatal and infant mortality. Synthetic and animal-derived surfactants from bovine as well as porcine origin have been evaluated in randomized controlled trials. Animal-derived surfactants generally result in faster weaning of respiratory support, shorter duration of invasive ventilation, and decreased mortality when compared to first- or second-generation of synthetic surfactants, but some of the second-generation synthetic surfactants are at least not inferior to the animal-derived surfactants. Using a higher initial dose of porcine derived surfactant may provide better outcomes when compared with using lower doses of bovine surfactants, likely, due to compositional difference and/or the dose. Third-generation synthetic surfactant containing peptide analogs of surfactant protein B and C are currently being studied. Less invasive intra-tracheal surfactant administration techniques in spontaneously breathing neonate receiving noninvasive ventilator support are also being evaluated. In the present era, prophylactic surfactant is not recommended as it may increase the risk of lung injury or death. In the future, surfactants may be used as vector to deliver steroids, or used in combination with molecules, such as, recombinant Club Cell Protein-10 (rhCC-10) to improve pulmonary outcomes. Also, noninvasive surfactant administration techniques, such as aerosolization or atomization of surfactant may play a greater role in the future.

Accuracy of pulse oximeter readings from probe placement on newborn wrist and ankle

Objective:To compare the accuracy of pulse oximetry oxygen saturation (SpO2) measured on the wrist compared with the ipsilateral palm, and SpO2 measured on the ankle compared with the ipsilateral sole.Study Design:In this prospective observational study, neonates admitted to the neonatal intensive care unit were enrolled. We recorded SpO2 (Masimo Radical-7 pulse oximeter) detected at the palm and ipsilateral wrist initially, then at 30 s, and at 1 min, and we repeated the same procedure over the sole and ipsilateral ankle. We recorded the time to obtain the SpO2 readings from all these sites. Regression analysis was performed to determine the relationship between paired SpO2 measurements. The mean difference (bias) and standard deviation of the paired SpO2 differences (precision) were calculated (Bland–Altman plots).Result:A total of 150 patients (birth weight 2381±1020 g, gestational age 34.3±4.3 weeks, median postnatal age 3.5 days (25th–75th percentile 1–16 days)) were enrolled. There was a good correlation between SpO2 measured at the palm versus the wrist (r=0.95, P<0.001 (right); r=0.97, P< 0.001 (left)) and between SpO2 measured at the sole versus the ankle (r=0.92, P<0.001 (right); r=0.91, P<0.001 (left)). There was also a good agreement between paired SpO2 measurements from these sites. The bias and precision for SpO2 at the right palm and right wrist was 0.08±0.94% and for the left palm and left wrist 0.22±0.87%. Similarly, the bias and precision for SpO2 at the right sole and right ankle was −0.03±0.93% and for the left sole and left ankle was −0.01±0.93%.Conclusion:Our results show that the wrist and ankle can be used as alternative sites to measure SpO2 in newborn infants in place of the routinely used palm or sole.

DEXAMETHASONE VERSUS HYDROCORTISONE FOR HYPOTENSION REFRACTORY TO HIGH DOSE INOTROPIC AGENTS AND INCIDENCE OF CANDIDA INFECTION IN EXTREMELY LOW BIRTH WEIGHT INFANTS. † 1425

DEXAMETHASONE VERSUS HYDROCORTISONE FOR HYPOTENSION REFRACTORY TO HIGH DOSE INOTROPIC AGENTS AND INCIDENCE OF CANDIDA INFECTION IN EXTREMELY LOW BIRTH WEIGHT INFANTS. † 1425

Acute effects of vecuronium on pulmonary function and hypoxemic episodes in preterm infants

Background: Varying effects of pancuronium on neonatal pulmonary mechanics have been documented, including a decrease in pulmonary compliance or no significant change in compliance; but measurements of respiratory mechanics or quantification of episodes of hypoxemia in preterm newborns receiving vecuronium (Norcuron, Bedford Labs, Bedford, OH, USA) have not been reported. The objective of the present study was to quantify the short‐term effects of vecuronium on pulmonary mechanics and episodes of hypoxemia in preterm infants receiving mechanical ventilation.

Validation of noninvasive hemoglobin measurement by pulse co-oximeter in newborn infants.

Objective:To describe the accuracy of noninvasive hemoglobin (Hb) obtained with pulse co-oximeter (SpHb) compared with total Hb (tHb) from laboratory co-oximeter in neonates.Study design:Neonates with birth weight (BW) <3000 g admitted to LAC+USC Medical Center neonatal intensive care unit were included. SpHb was recorded using Masimo Radical-7 and compared with tHb. A total of three data sets were obtained for each patient. Regression analysis and Bland–Altman analysis were performed.Result:Sixty-one patients (mean±s.d., BW 1177±610 g and gestational age 28.7±3.9 weeks) were enrolled. The mean tHb value was 13.9±2.0 g dl−1 and the mean SpHb was 14.0±2.0 g dl−1. There was a moderately positive correlation between SpHb and tHb (r=0.66, P<0.001) with a bias and precision of −0.09±1.67 g dl−1. Data from a subgroup of infants with gestational age ⩽32 weeks (52/61 patients) were analyzed, and the correlation coefficient was moderately positive (r=0.69, P<0.001) with a bias and precision of −0.23±1.60 g dl−1.Conclusion:Our results suggest that noninvasive SpHb may be considered as an adjunct to invasive tHb measurements in newborn infants <3000 g especially in preterm infants ⩽32 weeks of gestation.