Elizabeth Asztalos

Effects of Targeting Higher vs Lower Arterial Oxygen Saturations on Death or Disability in Extremely Preterm Infants: A Randomized Clinical Trial

IMPORTANCE The goal of oxygen therapy is to deliver sufficient oxygen to the tissues while minimizing oxygen toxicity and oxidative stress. It remains uncertain what values of arterial oxygen saturations achieve this balance in preterm infants. OBJECTIVE To compare the effects of targeting lower or higher arterial oxygen saturations on the rate of death or disability in extremely preterm infants. DESIGN, SETTING, AND PARTICIPANTS Randomized, double-blind trial in 25 hospitals in Canada, the United States, Argentina, Finland, Germany, and Israel in which 1201 infants with gestational ages of 23 weeks 0 days through 27 weeks 6 days were enrolled within 24 hours after birth between December 2006 and August 2010. Follow-up assessments began in October 2008 and ended in August 2012. INTERVENTIONS Study participants were monitored until postmenstrual ages of 36 to 40 weeks with pulse oximeters that displayed saturations of either 3% above or below the true values. Caregivers adjusted the concentration of oxygen to achieve saturations between 88% and 92%, which produced 2 treatment groups with true target saturations of 85% to 89% (n = 602) or 91% to 95% (n = 599). Alarms were triggered when displayed saturations decreased to 86% or increased to 94%. MAIN OUTCOMES AND MEASURES The primary outcome was a composite of death, gross motor disability, cognitive or language delay, severe hearing loss, or bilateral blindness at a corrected age of 18 months. Secondary outcomes included retinopathy of prematurity and brain injury. RESULTS Of the 578 infants with adequate data for the primary outcome who were assigned to the lower target range, 298 (51.6%) died or survived with disability compared with 283 of the 569 infants (49.7%) assigned to the higher target range (odds ratio adjusted for center, 1.08; 95% CI, 0.85 to 1.37; P = .52). The rates of death were 16.6% for those in the 85% to 89% group and 15.3% for those in the 91% to 95% group (adjusted odds ratio, 1.11; 95% CI, 0.80 to 1.54; P = .54). Targeting lower saturations reduced the postmenstrual age at last use of oxygen therapy (adjusted mean difference, -0.8 weeks; 95% CI, -1.5 to -0.1; P = .03) but did not alter any other outcomes. CONCLUSION AND RELEVANCE In extremely preterm infants, targeting oxygen saturations of 85% to 89% compared with 91% to 95% had no significant effect on the rate of death or disability at 18 months. These results may help determine the optimal target oxygen saturation. TRIAL REGISTRATIONS ISRCTN Identifier: 62491227; ClinicalTrials.gov Identifier: NCT00637169.

Survival Without Disability to Age 5 Years After Neonatal Caffeine Therapy for Apnea of Prematurity

CONTEXT Very preterm infants are prone to apnea and have an increased risk of death or disability. Caffeine therapy for apnea of prematurity reduces the rates of cerebral palsy and cognitive delay at 18 months of age. OBJECTIVE To determine whether neonatal caffeine therapy has lasting benefits or newly apparent risks at early school age. DESIGN, SETTING, AND PARTICIPANTS Five-year follow-up from 2005 to 2011 in 31 of 35 academic hospitals in Canada, Australia, Europe, and Israel, where 1932 of 2006 participants (96.3%) had been enrolled in the randomized, placebo-controlled Caffeine for Apnea of Prematurity trial between 1999 and 2004. A total of 1640 children (84.9%) with birth weights of 500 to 1250 g had adequate data for the main outcome at 5 years. MAIN OUTCOME MEASURES Combined outcome of death or survival to 5 years with 1 or more of motor impairment (defined as a Gross Motor Function Classification System level of 3 to 5), cognitive impairment (defined as a Full Scale IQ<70), behavior problems, poor general health, deafness, and blindness. RESULTS The combined outcome of death or disability was not significantly different for the 833 children assigned to caffeine from that for the 807 children assigned to placebo (21.1% vs 24.8%; odds ratio adjusted for center, 0.82; 95% CI, 0.65-1.03; P = .09). The rates of death, motor impairment, behavior problems, poor general health, deafness, and blindness did not differ significantly between the 2 groups. The incidence of cognitive impairment was lower at 5 years than at 18 months and similar in the 2 groups (4.9% vs 5.1%; odds ratio adjusted for center, 0.97; 95% CI, 0.61-1.55; P = .89). CONCLUSION Neonatal caffeine therapy was no longer associated with a significantly improved rate of survival without disability in children with very low birth weights who were assessed at 5 years.

Less-Tight versus Tight Control of Hypertension in Pregnancy

BACKGROUND The effects of less-tight versus tight control of hypertension on pregnancy complications are unclear. METHODS We performed an open, international, multicenter trial involving women at 14 weeks 0 days to 33 weeks 6 days of gestation who had nonproteinuric preexisting or gestational hypertension, office diastolic blood pressure of 90 to 105 mm Hg (or 85 to 105 mm Hg if the woman was taking antihypertensive medications), and a live fetus. Women were randomly assigned to less-tight control (target diastolic blood pressure, 100 mm Hg) or tight control (target diastolic blood pressure, 85 mm Hg). The composite primary outcome was pregnancy loss or high-level neonatal care for more than 48 hours during the first 28 postnatal days. The secondary outcome was serious maternal complications occurring up to 6 weeks post partum or until hospital discharge, whichever was later. RESULTS Included in the analysis were 987 women; 74.6% had preexisting hypertension. The primary-outcome rates were similar among 493 women assigned to less-tight control and 488 women assigned to tight control (31.4% and 30.7%, respectively; adjusted odds ratio, 1.02; 95% confidence interval [CI], 0.77 to 1.35), as were the rates of serious maternal complications (3.7% and 2.0%, respectively; adjusted odds ratio, 1.74; 95% CI, 0.79 to 3.84), despite a mean diastolic blood pressure that was higher in the less-tight-control group by 4.6 mm Hg (95% CI, 3.7 to 5.4). Severe hypertension (≥160/110 mm Hg) developed in 40.6% of the women in the less-tight-control group and 27.5% of the women in the tight-control group (P<0.001). CONCLUSIONS We found no significant between-group differences in the risk of pregnancy loss, high-level neonatal care, or overall maternal complications, although less-tight control was associated with a significantly higher frequency of severe maternal hypertension. (Funded by the Canadian Institutes of Health Research; CHIPS Current Controlled Trials number, ISRCTN71416914; ClinicalTrials.gov number, NCT01192412.).

Caffeine for Apnea of Prematurity trial: benefits may vary in subgroups

OBJECTIVE To determine whether the benefits of caffeine vary in three subgroups of 2006 participants in the Caffeine for Apnea of Prematurity (CAP) trial. STUDY DESIGN Post-hoc subgroup analyses were performed on the basis of: (1) indication for commencement of study drug: treat apnea, prevent apnea, or facilitate extubation; (2) positive pressure ventilation (PPV) at randomization: endotracheal tube (ETT), noninvasive ventilation, or none; and (3) timing of commencement of study drug: early or late (< or =3 versus >3 days). Outcomes assessed were those showing treatment effects in the original analyses. We investigated the consistency of caffeine effects by using regression models that incorporated treatment/subgroup factor interactions. RESULTS There was little evidence of a differential treatment effect of caffeine in subgroups defined by the clinical indication for starting study drug. The size and direction of the caffeine effect on death or disability differed depending on PPV at randomization (P = .03). Odds ratios (95% CI) were: no support, 1.32 (0.81-2.14); noninvasive support, 0.73 (0.52-1.03); and ETT, 0.73 (0.57-0.94). Adjustment for baseline factors strengthened this effect (P = .02). Starting caffeine early resulted in larger reductions in days of respiratory support. Postmenstrual age at time of discontinuing PPV was shorter with earlier treatment (P = .01). Mean differences (95% CI) were: early, 1.35 weeks (0.90-1.81); and late 0.55 weeks (-0.11-0.99). Adjustment for baseline factors weakened this effect (P = .03). CONCLUSIONS There is evidence of variable beneficial effects of caffeine. Infants receiving respiratory support appeared to derive more neurodevelopmental benefits from caffeine than infants not receiving support. Earlier initiation of caffeine may be associated with a greater reduction in time on ventilation.

Neurodevelopmental outcome of extremely low birth weight infants randomly assigned to restrictive or liberal hemoglobin thresholds for blood transfusion

BACKGROUND AND OBJECTIVE. Extremely low birth weight infants frequently receive red cell transfusions. We sought to determine whether a restrictive versus liberal hemoglobin transfusion threshold results in differences in death or adverse neurodevelopmental outcomes of extremely low birth weight infants. PATIENTS AND METHODS. Extremely low birth weight infants previously enrolled in the Preterm Infants in Need of Transfusion Trial, a randomized, controlled trial of low versus high hemoglobin transfusion thresholds, were followed up at 18 to 21 months’ corrected age. Erythrocyte transfusion was determined by an algorithm of low (restrictive) or high (liberal) hemoglobin transfusion thresholds, differing by 10 to 20 g/L and maintained until first hospital discharge. The primary composite outcome was death or the presence of cerebral palsy, cognitive delay, or severe visual or hearing impairment. RESULTS. Of 451 enrolled infants, the primary outcome was available in 430. There was no statistically significant difference in the primary outcome, found in 94 (45%) of 208 in the restrictive group and 82 (38%) of 213 in the liberal group. There were no statistically significant differences in preplanned secondary outcomes. However, the difference in cognitive delay (Mental Development Index score < 70) approached statistical significance. A posthoc analysis with cognitive delay redefined (Mental Development Index score < 85) showed a significant difference favoring the liberal threshold group. CONCLUSIONS. Maintaining the hemoglobin of extremely low birth weight infants at these restrictive rather than liberal transfusion thresholds did not result in a statistically significant difference in combined death or severe adverse neurodevelopmental outcome.

Growth and Nutrient Intakes of Human Milk–Fed Preterm Infants Provided With Extra Energy and Nutrients After Hospital Discharge

OBJECTIVES. The purpose of this pilot study was to determine whether mixing a multinutrient fortifier to approximately one half of the human milk fed each day for a finite period after discharge improves the nutrient intake and growth of predominantly human milk–fed low birth weight infants. We also assessed the impact of this intervention on the exclusivity of human milk feeding. METHODS. Human milk–fed (≥80% feeding per day) low birth weight (750–1800 g) infants (n = 39) were randomly assigned at hospital discharge to either a control or an intervention group. Infants in the control group were discharged from the hospital on unfortified human milk. Nutrient enrichment of human milk in the intervention group was achieved by mixing approximately one half of the human milk provided each day with a powdered multinutrient human milk fortifier for 12 weeks after discharge. Milk with added nutrients was estimated to contain ∼80 kcal (336 kJ) and 2.2 g protein/100 mL plus other nutrients. Intensive lactation support was provided to both groups. RESULTS. Infants in the intervention group were longer during the study period, and those born ≤1250 g had larger head circumferences than infants in the control group. There was a trend toward infants in the intervention group to be heavier at the end of the intervention compared with those in the control group. Mean protein, zinc, calcium, phosphorus, and vitamins A and D intakes were higher in the intervention group. CONCLUSIONS. Results from this study suggest that adding a multinutrient fortifier to approximately one half of the milk provided to predominantly human milk–fed infants for 12 weeks after hospital discharge may be an effective strategy in addressing early discharge nutrient deficits and poor growth without unduly influencing human milk feeding when intensive lactation support is provided.

Prevention and 18-Month Outcomes of Serious Pulmonary Hemorrhage in Extremely Low Birth Weight Infants: Results From the Trial of Indomethacin Prophylaxis in Preterms

OBJECTIVES. A patent ductus arteriosus is a risk factor for pulmonary hemorrhage; however, despite halving the incidence of patent ductus arteriosus, indomethacin prophylaxis did not reduce the rate of pulmonary hemorrhage in the Trial of Indomethacin Prophylaxis in Preterms. Inclusion of mild bleeds after trauma to the upper airways may have masked a beneficial drug effect. Using the Trial of Indomethacin Prophylaxis in Preterms database, we studied the effect of prophylactic indomethacin on the prevention of serious hemorrhages in extremely low birth weight infants. We also compared the 18-month outcomes of infants with and without a serious pulmonary bleed. METHODS. Pulmonary hemorrhage was classified as serious when it was treated with increased ventilator support, a higher concentration of oxygen, or transfusion of blood products. The cumulative risk for serious pulmonary hemorrhage was estimated for the first week of life and for the entire NICU stay. Poor outcome at a corrected age of 18 months was death or survival with cerebral palsy, cognitive delay, blindness, and/or deafness. RESULTS. A total of 123 (10.2%) of 1202 infants developed a serious pulmonary hemorrhage. During week 1, prophylactic indomethacin reduced the risk for serious pulmonary hemorrhage by 35%; however, during the entire NICU stay, the risk for such hemorrhages was decreased by only 23%. A reduced risk for patent ductus arteriosus explained 80% of the beneficial effect of prophylactic indomethacin on serious pulmonary bleeds. The risks for death or for survival with neurosensory impairment were doubled after a serious pulmonary hemorrhage. CONCLUSIONS. Extremely low birth weight infants with serious pulmonary hemorrhage have an increased risk for poor long-term outcome. Prophylactic indomethacin reduces the rate of early serious pulmonary hemorrhage, mainly through its action on patent ductus arteriosus. Prophylactic indomethacin is less effective in preventing serious pulmonary hemorrhages that occur after the first week of life.

Growth and body composition of human milk-fed premature infants provided with extra energy and nutrients early after hospital discharge: 1-year follow-up.

Objectives: Human milk (HM) is the optimal source of nutrition for premature infants; however, it is unclear whether HM alone is sufficient to meet their elevated nutritional requirements early after hospital discharge. We previously reported that premature infants (750–1800 g birth weight) fed HM containing extra nutrients for 12 weeks after discharge had dietary intakes closer to recommended levels and grew more rapidly than those fed HM alone. The objectives of the present article are to examine the impact of this intervention on bone mineralization, body composition, and HM use up to 1 year. Data are also presented on general developmental level at 18-month corrected age (CA). Patients and Methods: At discharge, predominantly HM-fed infants were randomized to receive for 12 weeks either approximately half of their feedings containing a multinutrient fortifier (intervention, n = 19) or all of their feedings as HM alone (control, n = 20). Results: Intervention infants remained longer (P < 0.001) and had greater whole-body bone mineral content (P = 0.02) until 12-month CA compared with controls. Intervention infants born less than or equal to 1250 g continued to have a larger mean head circumference throughout the first year of life (P < 0.0001). Human milk feeding (mL · kg−1 · day−1) differed between groups at 6- (P = 0.035), but not 12-month CA. No statistically significant differences were found between groups in the mental, motor, or behavior rating scale scores of the Bayley II at 18-month CA. Conclusions: Adding a multinutrient fortifier to HM provided to predominantly HM-fed premature infants early after discharge results in sustained differences in weight, length, and whole-body bone mineral content, and in smaller babies, head circumference for the first year of life.

Pain behaviours in Extremely Low Gestational Age infants.

BACKGROUND To date, there are over 40 infant pain measures. Despite this plethora of measures, only 8 have included preterm infants and only 2 have included Extremely Low Gestational Age (ELGA; infants <28 weeks GA) in their development. Without reliable, valid and clinically useful indicators for procedural pain in ELGA infants, clinicians have no means to interpret the responses from an immature infant who may respond differently from infants of older GA. OBJECTIVE To examine the physiological, behavioural and biochemical responses to painful and non-painful procedures in ELGA infants and the influence of GA and sex. DESIGN/METHODS A prospective crossover design with 50 ELGA infants from one Canadian tertiary level NICU was conducted. Infants were assessed in random order during standardized painful (heel lance) and non-painful (diaper change) procedures. Physiological (heart rate, oxygen saturation) and behavioural (facial and body movement) indicators were continuously collected during 4 phases of the procedures. Biochemical (salivary cortisol) indicators were collected immediately before and 20 min following the procedures. RESULTS Four facial actions (brow bulge, eye squeeze, nasolabial furrow, vertical mouth stretch) increased immediately following the heel lance. There were no specific changes in physiological, body movement or cortisol indicators following the heel lance. ELGA infants demonstrated greater body movements during the diaper change, which may reflect immature motor coordination. No differences in pain responses were found for infants born between 23-25 6/7 weeks GA and those between 26-28 weeks GA. Similarly, no gender differences were found. CONCLUSIONS Changes in 4 facial actions were the most sensitive indicators of pain in ELGA infants. This finding is consistent with existing measures where facial actions are the most prominent pain indicators. Specific body movements such as those included in NIDCAP, may provide more information about pain in ELGA infants. Movements such as hand-on-face, finger splaying, fisting, arching or yawning need to be examined in future research.

Effect of antenatal corticosteroids on fetal growth and gestational age at birth

OBJECTIVE: To estimate the effect of multiple courses of antenatal corticosteroids on neonatal size, controlling for gestational age at birth and other confounders, and to determine whether there was a dose–response relationship between number of courses of antenatal corticosteroids and neonatal size. METHODS: This is a secondary analysis of the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study, a double-blind randomized controlled trial of single compared with multiple courses of antenatal corticosteroids in women at risk for preterm birth and in which fetuses administered multiple courses of antenatal corticosteroids weighed less, were shorter, and had smaller head circumferences at birth. All women (n=1,858) and children (n=2,304) enrolled in the Multiple Courses of Antenatal Corticosteroids for Preterm Birth Study were included in the current analysis. Multiple linear regression analyses were undertaken. RESULTS: Compared with placebo, neonates in the antenatal corticosteroids group were born earlier (estimated difference and confidence interval [CI]: −0.428 weeks, CI −0.10264 to −0.75336; P=.01). Controlling for gestational age at birth and confounding factors, multiple courses of antenatal corticosteroids were associated with a decrease in birth weight (−33.50 g, CI −66.27120 to −0.72880; P=.045), length (−0.339 cm, CI −0.6212 to −0.05676]; P=.019), and head circumference (−0.296 cm, −0.45672 to −0.13528; P<.001). For each additional course of antenatal corticosteroids, there was a trend toward an incremental decrease in birth weight, length, and head circumference. CONCLUSION: Fetuses exposed to multiple courses of antenatal corticosteroids were smaller at birth. The reduction in size was partially attributed to being born at an earlier gestational age but also was attributed to decreased fetal growth. Finally, a dose–response relationship exists between the number of corticosteroid courses and a decrease in fetal growth. The long-term effect of these findings is unknown. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00187382. LEVEL OF EVIDENCE: II