Association between Intermittent Hypoxemia and Severe Bronchopulmonary Dysplasia in Preterm Infants.

Rationale: Bronchopulmonary dysplasia increases the risk of disability in extremely preterm infants. Although the pathophysiology remains uncertain, prior exposure to intermittent hypoxemia may play a role in this relationship. Objectives: To determine the association between prolonged episodes of intermittent hypoxemia and severe bronchopulmonary dysplasia. Methods: A post hoc analysis of extremely preterm infants in the Canadian Oxygen Trial who survived to 36 weeks' postmenstrual age was performed. Oxygen saturations <80% for ⩾1 minute and the proportion of time per day with hypoxemia were quantified using continuous pulse oximetry data that had been sampled every 10 seconds from within 24 hours of birth until 36 weeks' postmenstrual age. The study outcome was severe bronchopulmonary dysplasia as defined in the 2001 NIH Workshop Summary. Measurements and Main Results: Of 1,018 infants, 332 (32.6%) developed severe bronchopulmonary dysplasia. The median number of hypoxemic episodes ranged from 0.8/day (interquartile range, 0.2-1.1) to 60.2/day (interquartile range, 51.4-70.3) among the least and most affected 10% of infants. Compared with the lowest decile of exposure to hypoxemic episodes, the adjusted relative risk of severe bronchopulmonary dysplasia increased progressively from 1.72 (95% confidence interval, 1.55-1.90) at the 2nd decile to 20.40 (95% confidence interval, 12.88-32.32) at the 10th decile. Similar risk gradients were observed for time in hypoxemia. Significant differences in the rates of hypoxemia between infants with and without severe bronchopulmonary dysplasia emerged within the first week after birth. Conclusions: Prolonged intermittent hypoxemia beginning in the first week after birth was associated with an increased risk of developing severe bronchopulmonary dysplasia among extremely preterm infants. Clinical trial registered with www.isrctn.com (ISRCTN62491227) and www.clinicaltrials.gov (NCT00637169).

Higher or Lower Hemoglobin Transfusion Thresholds for Preterm Infants.

BACKGROUND: Limited data suggest that higher hemoglobin thresholds for red-cell transfusions may reduce the risk of cognitive delay among extremely-low-birth-weight infants with anemia. METHODS: We performed an open, multicenter trial in which infants with a birth weight of 1000 g or less and a gestational age between 22 weeks 0 days and 28 weeks 6 days were randomly assigned within 48 hours after delivery to receive red-cell transfusions at higher or lower hemoglobin thresholds until 36 weeks of postmenstrual age or discharge, whichever occurred first. The primary outcome was a composite of death or neurodevelopmental impairment (cognitive delay, cerebral palsy, or hearing or vision loss) at 22 to 26 months of age, corrected for prematurity. RESULTS: A total of 1824 infants (mean birth weight, 756 g; mean gestational age, 25.9 weeks) underwent randomization. There was a between-group difference of 1.9 g per deciliter (19 g per liter) in the pretransfusion mean hemoglobin levels throughout the treatment period. Primary outcome data were available for 1692 infants (92.8%). Of 845 infants in the higher-threshold group, 423 (50.1%) died or survived with neurodevelopmental impairment, as compared with 422 of 847 infants (49.8%) in the lower-threshold group (relative risk adjusted for birth-weight stratum and center, 1.00; 95% confidence interval [CI], 0.92 to 1.10; P = 0.93). At 2 years, the higher- and lower-threshold groups had similar incidences of death (16.2% and 15.0%, respectively) and neurodevelopmental impairment (39.6% and 40.3%, respectively). At discharge from the hospital, the incidences of survival without severe complications were 28.5% and 30.9%, respectively. Serious adverse events occurred in 22.7% and 21.7%, respectively. CONCLUSIONS: In extremely-low-birth-weight infants, a higher hemoglobin threshold for red-cell transfusion did not improve survival without neurodevelopmental impairment at 22 to 26 months of age, corrected for prematurity. (Funded by the National Heart, Lung, and Blood Institute and others; TOP ClinicalTrials.gov number, NCT01702805.).

Oxygen saturation target ranges and alarm settings in the NICU: What have we learnt from the neonatal oxygenation prospective meta-analysis (NeOProM)?

The Neonatal Oxygenation Prospective Meta-analysis combined the individual participant data of 4965 extremely preterm infants. They had been randomly assigned in 5 trials to arterial oxygen saturations of 85%-89% or 91%-95% using modified oximeters to mask the treatment allocation. The primary outcome of death or disability did not differ significantly between the groups. Assignment to the higher target range reduced the risks of death and severe necrotizing enterocolitis but increased the risk of treated retinopathy. Trade-offs between the benefits and risks of higher or lower saturation targets should be informed by the local patient risks and institutional rates for outcomes that may be affected by a policy change. Features of the oximeter masking algorithm introduced unanticipated artifacts into the saturation display that are not seen in routine care. NeOProM provides little guidance on where to set the oximeter alarms and how to respond to them.

What Is New about Transfusions for Preterm Infants? An Update.

Currently the question of whether to maintain a higher hemoglobin level by transfusing more liberally, as opposed to a more restrictive strategy with lower hemoglobin maintenance levels, has not been answered. We review summarized conclusions of a Cochrane systematic review and meta-analysis of 614 infants in 4 randomized controlled trials (RCT) pooling data. This suggests potential benefits of higher hemoglobin levels, i.e., a possible improved cognition of infants at 18-21 months' corrected age and a reduction of apnea. However, the data on cognition is hypothesis generating as it derives from a post hoc analysis from a single trial in 451 infants. Moreover, the data on apnea need confirmation in larger trials. The effect of adding data of cognitive 2-year outcomes of 1,744 infants from 2 RCT, which will be reported soon, should expand our understanding. This new data will need to be integrated with the older generation of RCTs but also with emerging suggestions from observational data on potential risks of blood transfusions. We discuss some of these warnings from observational studies. Finally, we ask whether we are ready to individualize blood transfusion to physiological measures made in individual infants, and we point to some current difficulties hindering this step.

Association Between Oxygen Saturation Targeting and Death or Disability in Extremely Preterm Infants in the Neonatal Oxygenation Prospective Meta-analysis Collaboration.

Importance: There are potential benefits and harms of hyperoxemia and hypoxemia for extremely preterm infants receiving more vs less supplemental oxygen. Objective: To compare the effects of different target ranges for oxygen saturation as measured by pulse oximetry (Spo2) on death or major morbidity. Design, Setting, and Participants: Prospectively planned meta-analysis of individual participant data from 5 randomized clinical trials (conducted from 2005-2014) enrolling infants born before 28 weeks' gestation. Exposures: Spo2 target range that was lower (85%-89%) vs higher (91%-95%). Main Outcomes and Measures: The primary outcome was a composite of death or major disability (bilateral blindness, deafness, cerebral palsy diagnosed as ≥2 level on the Gross Motor Function Classification System, or Bayley-III cognitive or language score <85) at a corrected age of 18 to 24 months. There were 16 secondary outcomes including the components of the primary outcome and other major morbidities. Results: A total of 4965 infants were randomized (2480 to the lower Spo2 target range and 2485 to the higher Spo2 range) and had a median gestational age of 26 weeks (interquartile range, 25-27 weeks) and a mean birth weight of 832 g (SD, 190 g). The primary outcome occurred in 1191 of 2228 infants (53.5%) in the lower Spo2 target group and 1150 of 2229 infants (51.6%) in the higher Spo2 target group (risk difference, 1.7% [95% CI, -1.3% to 4.6%]; relative risk [RR], 1.04 [95% CI, 0.98 to 1.09], P = .21). Of the 16 secondary outcomes, 11 were null, 2 significantly favored the lower Spo2 target group, and 3 significantly favored the higher Spo2 target group. Death occurred in 484 of 2433 infants (19.9%) in the lower Spo2 target group and 418 of 2440 infants (17.1%) in the higher Spo2 target group (risk difference, 2.8% [95% CI, 0.6% to 5.0%]; RR, 1.17 [95% CI, 1.04 to 1.31], P = .01). Treatment for retinopathy of prematurity was administered to 220 of 2020 infants (10.9%) in the lower Spo2 target group and 308 of 2065 infants (14.9%) in the higher Spo2 target group (risk difference, -4.0% [95% CI, -6.1% to -2.0%]; RR, 0.74 [95% CI, 0.63 to 0.86], P < .001). Severe necrotizing enterocolitis occurred in 227 of 2464 infants (9.2%) in the lower Spo2 target group and 170 of 2465 infants (6.9%) in the higher Spo2 target group (risk difference, 2.3% [95% CI, 0.8% to 3.8%]; RR, 1.33 [95% CI, 1.10 to 1.61], P = .003). Conclusions and Relevance: In this prospectively planned meta-analysis of individual participant data from extremely preterm infants, there was no significant difference between a lower Spo2 target range compared with a higher Spo2 target range on the primary composite outcome of death or major disability at a corrected age of 18 to 24 months. The lower Spo2 target range was associated with a higher risk of death and necrotizing enterocolitis, but a lower risk of retinopathy of prematurity treatment.

Benefits of Oxygen Saturation Targeting Trials: Oximeter Calibration Software Revision and Infant Saturations.

It has been reported in the 3 Benefits of Oxygen Saturation Targeting (BOOST-II) trials that changes in oximeter calibration software resulted in clearer separation between the oxygen saturations in the two trial target groups. A revised analysis of the published BOOST-II data does not support this conclusion.

The Effect of Skin Pigmentation on the Accuracy of Pulse Oximetry in Infants with Hypoxemia.

To compare pulse oximetry measurement bias between infants with hypoxemia with either dark skin or light skin with Masimo Radical 7 and Nellcor Oximax. There was no significant difference in systematic bias based on skin pigment for either oximeter.

Effects of Targeting Higher or Lower Oxygen Saturations in Centers with More Versus Less Separation between Median Saturations.

Subgroup analysis of the Canadian Oxygen Trial to compare outcomes of extremely preterm infants in centers with more versus less separation between median arterial oxygen saturations in the two target ranges. Centers with more separation observed lower rates of death or disability in the 85%-89% range than in the 91%-95% target range.

Association Between Intermittent Hypoxemia or Bradycardia and Late Death or Disability in Extremely Preterm Infants.

IMPORTANCE: Extremely preterm infants may experience intermittent hypoxemia or bradycardia for many weeks after birth. The prognosis of these events is uncertain. OBJECTIVE: To determine the association between intermittent hypoxemia or bradycardia and late death or disability. DESIGN, SETTING, AND PARTICIPANTS: Post hoc analysis of data from the inception cohort assembled for the Canadian Oxygen Trial in 25 hospitals in Canada, the United States, Argentina, Finland, Germany, and Israel, including 1019 infants with gestational ages of 23 weeks 0 days through 27 weeks 6 days who were born between December 2006 and August 2010 and survived to a postmenstrual age of 36 weeks. Follow-up assessments occurred between October 2008 and August 2012. EXPOSURES: Episodes of hypoxemia (pulse oximeter oxygen saturation <80%) or bradycardia (pulse rate <80/min) for 10 seconds or longer. Values were sampled every 10 seconds within 24 hours after birth until at least 36 weeks' postmenstrual age. MAIN OUTCOMES AND MEASURES: The primary outcome was a composite of death after 36 weeks' postmenstrual age, motor impairment, cognitive or language delay, severe hearing loss, or bilateral blindness at 18 months' corrected age. Secondary outcomes were motor impairment, cognitive or language delay, and severe retinopathy of prematurity. RESULTS: Downloaded saturation and pulse rate data were available for a median of 68.3 days (interquartile range, 56.8-86.0 days). Mean percentages of recorded time with hypoxemia for the least and most affected 10% of infants were 0.4% and 13.5%, respectively. Corresponding values for bradycardia were 0.1% and 0.3%. The primary outcome was ascertained for 972 infants and present in 414 (42.6%). Hypoxemic episodes were associated with an estimated increased risk of late death or disability at 18 months of 56.5% in the highest decile of hypoxemic exposure vs 36.9% in the lowest decile (modeled relative risk, 1.53; 95% CI, 1.21-1.94). This association was significant only for prolonged hypoxemic episodes lasting at least 1 minute (relative risk, 1.66; 95% CI, 1.35-2.05 vs for shorter episodes, relative risk, 1.01; 95% CI, 0.77-1.32). Relative risks for all secondary outcomes were similarly increased after prolonged hypoxemia. Bradycardia did not alter the prognostic value of hypoxemia. CONCLUSIONS AND RELEVANCE: Among extremely preterm infants who survived to 36 weeks' postmenstrual age, prolonged hypoxemic episodes during the first 2 to 3 months after birth were associated with adverse 18-month outcomes. If confirmed in future studies, further research on the prevention of such episodes is needed.

Effect of cobedding twins on coregulation, infant state, and twin safety.

OBJECTIVE: To evaluate the efficacy of cobedding on twin coregulation and twin safety. DESIGN: Randomized controlled trial (RCT). SETTING: Two university affiliated Level III neonatal intensive care units (NICUs). PARTICIPANTS: One hundred and seventeen sets (N = 234) of stable preterm twins (<37 weeks gestational age at birth) admitted to the NICU. METHODS: Sets of twins were randomly assigned to be cared for in a single cot (cobedded) or in separate cots (standard care). State response was obtained from videotaped and physiologic data measured and recorded for three, 3-hour sessions over a one-week study period. Tapes were coded for infant state by an assessor blind to the purpose of the study. RESULTS: Twins who were cobedded spent more time in the same state (p < .01), less time in opposite states (p < .01), were more often in quiet sleep (p < .01) and cried less (p < .01) than twins who were cared for in separate cots. There was no difference in physiological parameters between groups (p = .85). There was no difference in patient safety between groups (incidence of sepsis, p = .95), incidence of caregiver error (p = .31), and incidence of apnea (p = .70). CONCLUSIONS: Cobedding promotes self-regulation and sleep and decreases crying without apparent increased risk.

Impact of study oximeter masking algorithm on titration of oxygen therapy in the Canadian oxygen trial.

OBJECTIVE: To compare oxygen saturations as displayed to caregivers on offset pulse oximeters in the 2 groups of the Canadian Oxygen Trial. STUDY DESIGN: In 5 double-blind randomized trials of oxygen saturation targeting, displayed saturations between 88% and 92% were offset by 3% above or below the true values but returned to true values below 84% and above 96%. During the transition, displayed values remained static at 96% in the lower and at 84% in the higher target group during a 3% change in true saturations. In contrast, displayed values changed rapidly from 88% to 84% in the lower and from 92% to 96% in the higher target group during a 1% change in true saturations. We plotted the distributions of median displayed saturations on days with >12 hours of supplemental oxygen in 1075 Canadian Oxygen Trial participants to reconstruct what caregivers observed at the bedside. RESULTS: The oximeter masking algorithm was associated with an increase in both stability and instability of displayed saturations that occurred during the transition between offset and true displayed values at opposite ends of the 2 target ranges. Caregivers maintained saturations at lower displayed values in the higher than in the lower target group. This differential management reduced the separation between the median true saturations in the 2 groups by approximately 3.5%. CONCLUSIONS: The design of the oximeter masking algorithm may have contributed to the smaller-than-expected separation between true saturations in the 2 study groups of recent saturation targeting trials in extremely preterm infants.

Red blood cell transfusion in newborn infants.

Red blood cell transfusion is an important and frequent component of neonatal intensive care. The present position statement addresses the methods and indications for red blood cell transfusion of the newborn, based on a review of the current literature. The most frequent indications for blood transfusion in the newborn are the acute treatment of perinatal hemorrhagic shock and the recurrent correction of anemia of prematurity. Perinatal hemorrhagic shock requires immediate treatment with large quantities of red blood cells; the effects of massive transfusion on other blood components must be considered. Some guidelines are now available from clinical trials investigating transfusion in anemia of prematurity; however, considerable uncertainty remains. There is weak evidence that cognitive impairment may be more severe at follow-up in extremely low birth weight infants transfused at lower hemoglobin thresholds; therefore, these thresholds should be maintained by transfusion therapy. Although the risks of transfusion have declined considerably in recent years, they can be minimized further by carefully restricting neonatal blood sampling.

La transfusion de culot globulaire est un élément important et fréquent des soins intensifs néonatals. Le présent document de principes traite des méthodes et des indications pour transfuser des culots globulaires au nouveau-né, d'après une analyse bibliographique. Les principales indications de transfusion sanguine au nouveau-né sont le traitement aigu du choc hémorragique périnatal et la correction récurrente de l'anémie de la prématurité. Le choc hémorragique périnatal exige l'administration immédiate de fortes quantités de culots globulaires, mais il faut tenir compte des effets d'une transfusion massive sur d'autres composants sanguins. Grâce à des essais cliniques sur les transfusions en cas d'anémie de la prématurité, il est désormais possible de compter sur des lignes directrices, même s'il reste beaucoup d'incertitude. D'après des données dont la qualité de preuves est faible, l'atteinte cognitive pourrait être plus grave au suivi chez les nouveau-nés d'extrême petit poids à la naissance qui sont transfusés à des seuils d'hémoglobine bas. Il faut donc maintenir ces seuils par thérapie transfusionnelle. Même si les risques de transfusion ont diminué considérablement ces dernières années, on peut les réduire encore davantage en limitant soigneusement les ponctions capillaires néonatales.

Two cases of apparent suffocation of newborns during side-lying breastfeeding.

The side-lying position is one of several options offered to women in the postpartum period to assist with early establishment of breastfeeding. Many new mothers are exhausted and experiencing significant pain following birth. While the side-lying position for breastfeeding can allow women to get needed rest, it can increase their risk of falling asleep while in this position and potentially smothering their babies. We report two cases of apparent suffocation in newborns on the maternity ward when women unintentionally fell asleep while breastfeeding in the side-lying position. Interventions that may help to prevent such events are suggested.

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.

International survey of transfusion practices for extremely premature infants.

Our objective was to survey neonatologists regarding international practice of red cell transfusion thresholds for premature infants with <1000-g birth weight and/or <28-week gestation. An invitation to fill out an 11-question web-based survey was distributed to neonatologists through their professional societies in 22 countries. Physicians were asked about which specific factors, in addition to hemoglobin levels, influenced their decisions about transfusing premature infants. These factors included gestational age, postnatal age, oxygen need, respiratory support, reticulocyte count, and inotropic support. Physicians were presented with 5 scenarios and asked to identify hemoglobin cutoff values for transfusing infants with <1000-g birth weight and/or <28-week gestation. One thousand eighteen neonatologists responded: the majority were from the United States (67.5%), followed by Germany (10.7%), Japan (8.0%), the United Kingdom (4.9%), Spain (3.9%), Italy (2.6%), Colombia (0.6%), Argentina (0.4%), Canada (0.4%), Belgium (0.1%), and the Netherlands (0.1%). Half of the respondents (51.1%) reported having a written policy with specific red cell transfusion guidelines in their unit. Factors considered "very important" regarding the need to administer blood transfusions included degree of oxygen requirement (44.7%) and need for respiratory support (44.1%). Erythropoietin was routinely used to treat anemia by 26.0% of respondents. Delayed cord clamping or cord milking was practiced by 29.1% of respondents. The main finding was of a wide variation in the hemoglobin values used to transfuse infants, regardless of postnatal age. Step-wise increments in the median hemoglobin cutoffs directly paralleled an increase in the need for levels of respiratory support. In the first week of life, there was a wider range in the distribution of hemoglobin transfusion thresholds for infants requiring no respiratory support and full mechanical ventilation compared with the thresholds used in the second, third, and fourth weeks of life. An international survey using hypothetical scenarios shows that red blood cell transfusion practices vary widely among practicing neonatologists in participating countries.

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

Surviving extremely low-birth-weight infants are at risk of severe neurodevelopmental disability. Transfusion with packed red cells is almost universal in the care of these infants, but the hemoglobin threshold at which these transfusions should be given is unclear. Different clinical trials of restrictive (low hemoglobin) versus liberal (high hemoglobin) thresholds have addressed either neurodevelopmental outcomes at 18-21 months of corrected gestational age or psychological tests and brain imaging at 8-15 years of age. Early follow-up shows differences in cognitive outcome favoring the liberal strategy, but as a post hoc secondary outcome. The childhood studies favor the restrictive strategy, but include major methodological problems of secondary recruitment. No firm conclusion can be reached, other than to report that serious adverse effects may be attributable to one or other of these strategies, that prudent practice is to remain within trial protocols, and that further redesigned clinical trials are required.

Neonatal management and safe discharge of late and moderate preterm infants.

Late and moderate preterm infants form the majority of admissions for prematurity to special care neonatal nurseries. Although at risk for acute disorders of prematurity, they do not suffer the serious long term risks and chronic illnesses of the extremely premature. The special challenges addressed here are of transition and of thermal adaptation, nutritional compensation for postnatal growth restriction, the establishment of early feeding, and the avoidance of post-discharge jaundice or apnea. These 'healthy' premature infants provide challenges for discharge planning, in that opportunities may be available for discharge well before the expected date of delivery, which should be pursued. Barriers to early discharge are rigid conservative protocols and unwarranted investigations; facilitators of discharge are individualized care by nurses expert in cue-based feeding, early management of the thermal environment, support of family preferences and encouragement of mother-baby interactions. Safe discharge depends on recognizing these opportunities and applying strategies to address them.