In This Issue
NRP: Supporting Normal Physiology... Finally?
by Pat Scheans DNP, NNP-BC
When the American Academy of Pediatrics/American Heart Association Neonatal Resuscitation Program (NRP) was first released in 1987, a collective sigh of relief was heard in resuscitation rooms from coast to coast. Prior to the NRP algorithm begin developed, newly born infants in need of resuscitation might receive calcium, atropine, albumin or anything else someone in the delivery room (always separate from the labor room) felt might be beneficial. Afterward, especially if the resuscitation didn’t go well, one was left wondering whether enough was done, or even if the right thing was done.
Now, 30 years later, the NRP has been updated every five years based on the latest research; neonatal resuscitation teams remain reassured that, if they follow the latest algorithm, they have done everything they can using accepted evidence-based best practices. That said, one of the confounding things, in this writer’s opinion, is the number of interventions that have been modified over the years that were initiated without evidence to support the practice in the FIRST place. In fact, evidence had to be provided to STOP doing things for which we had no evidence – things that weren’t even based on physiology. One example of this is the practice of immediate cord clamping. Originally thought to help prevent postpartum hemorrhage (and to facilitate rapid access to the infant for resuscitation purposes), this intervention was initiated without best evidence, nor apparently with a thought to normal newborn transitional physiology. It has since been shown that there is no significant difference in postpartum hemorrhage rates with early and late cord clamping (generally between one and three minutes), and that neonatal outcomes (reduction in intraventricular hemorrhage in preterms, improved iron stores) are enhanced by not immediately clamping the umbilical cord (McDonald, Middleton, Dowswell, & Morris, 2014).
We now know that delayed/timed/physiologic/optimum cord clamping, particularly once respirations are established, promotes a smoother cardiovascular transition (ACOG, 2017). Supporting normal physiology by allowing blood to flow to the lungs and return to the heart before clamping/interrupting cardiac preload makes perfect sense, and NRP supports this practice if the umbilical cord and placenta are intact. Benefit to the pulmonary system has been shown when optimum clamping or cord milking is accompanied by lung inflation, and there is emerging evidence for optimum cord clamping when resuscitation is needed (Winter, et al., 2016; Meyer, Nevill, & Wong, 2017). And, indeed, while more research is needed to explore the potential benefits of resuscitation with the cord intact, it only makes physiologic sense that, for example, once the delivery occurs post shoulder dystocia, that the limp, apneic neonate be assisted with ventilation while attached to the placenta (the fetal lungs) while blood volume is being redistributed from the placenta and restored in the neonate.
One thing we don’t know about optimum cord clamping and resuscitation is how to account for the time interval between birth and cord clamping. Currently there is practice variation worldwide in when birth time is called (Niermeyer & Velaphi, 2013). Would a more useful time measurement for resuscitative efforts be from time of cord clamping and breathing/establishment of respirations rather than when the infant’s body emerges? Stay tuned.
Once pulse oximetry was invented in the 1980s, investigators were able to document the normal trajectory of fetal to neonatal oxygenation from 60% to 95% over 8-9 minutes. Had Virginia Apgar had access to this information, the normal scores that are named after her would have been 8 and 8 at 1 and 5 minutes of life respectively since normal newborns are visibly cyanotic during that time. Harris et al. (1986) showed almost 20 years ago that newborns benefited from room air resuscitation with improved Apgar scores and shortened time to first cry. In addition, somewhere around this point a giant “Aha!” was heard as reports emerged on the effects of oxidative stress and free radical damage on neonatal DNA and tissues. This led to the use of targeted saturation ranges and the end of administering a potentially toxic substance to newborns unnecessarily- a practice that we had begun without evidence to support its use in the first place, yet were loathe to give up (Saugstad, Rootwelt & Aalen, 1998).
Another practice that likely wouldn’t pass muster these days – and no institutional review board (IRB) would probably approve a study of – is the management of the infant born through meconium-stained amniotic fluid. Over the years, thanks to work by Wiswell et al. (2000), endotracheal intubation has been de-emphasized by the NRP. Now, in the 7th edition of the NRP, intubation and suctioning of the airway of an infant born through meconium-stained amniotic fluid is no longer recommended. All together now…”HALLELUJAH!” Again, there was little evidence to support this practice in the first place, and years later it had to be proven to be without benefit. How many depressed infants were further depressed by our efforts to “help” them, we’ll never know.
We actually know very little about outcomes related to the intervention and timing of NRP. Newborns are considered a vulnerable population making IRB approval rigorous, and rightly so. (The room air resuscitation studies were done in countries where oxygen was not always available). Little evidence exists to show how long it actually takes to perform the steps of NRP effectively, or whether outcomes vary based on how long it takes to accomplish the actions of the algorithm. The latest algorithm timing has eliminated the 30 second mark for initial steps, opting instead for the “Golden Minute” (Saugstad, Robertson & Vento, 2016). We can use our knowledge of physiology to surmise that pouring epinephrine into wet, un-perfused lungs is probably an ineffective practice. That said, we lack evidence about how soon intravenous epinephrine must be administered in order to be effective, or even the most effective dose (yes, a range for epinephrine dosing remains in the new algorithm). It makes intuitive sense that sooner is better. It also makes sense to avoid doing math calculations during an emergency – no help there from the NRP, so develop a safe way for your institution.
Using evidence-based practice is de rigueur in healthcare today. Checklists and algorithms improve patient safety as our scientific knowledge continues to grow. Nursing research contributes to the evidence-base on an ever-increasing level, and perinatal and neonatal nurses contribute to the well-being of their patients in myriad ways. Supporting normal physiology is an important public health measure for newborns. Best of all, there are practices and interventions that are FREE, yet impart lifelong health benefits. Skin to skin care, optimum cord clamping and breastfeeding are examples of free actions that support normal physiology, improve health, and save unknowable amounts of healthcare dollars world-wide.
In summary, I apologize to all the newborns that I separated from their moms and routinely suctioned and gave oxygen to willy-nilly. Mea culpa, I simply didn’t know any better. §
ACOG Committee Opinion No. 684: Delayed umbilical cord clamping after birth. (2017). Obstetrics and gynecology, 129(1):e5-e10, doi: 10.1097/AOG.0000000000001860
Harris, A. P., Sendak, M. J., & Donham, R. T. (1986). Changes in arterial oxygen saturation immediately after birth in the human neonate. The Journal of pediatrics, 109(1), 117-119. doi:10.1016/S0022-3476(86)80589-3
Ikuta, Linda, and Ksenia Zukowsky. (2015). 7th edition NRP brings big changes for NRP instructors. Advances in Neonatal Care, 15(2), 86-93. doi: 10.1097/ANC.0000000000000194
McDonald, S. J., Middleton, P., Dowswell, T., & Morris, P. S. (2014). Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes. Evidence‐Based Child Health: A Cochrane Review Journal, 9(2), 303-397. doi: 10.1002/ebch.1971
Meyer, M. P., Nevill, E., & Wong, M. M. (2017). Provision of respiratory support compared to no respiratory support before cord clamping for preterm infants. The Cochrane Library. (pending)
Niermeyer S, Velaphi S. (2013). Promoting physiologic transition at birth: re-examining resuscitation and the timing of cord clamping, Seminars in Fetal & Neonatal Medicine, 18, 385-392. doi: 10.1016/j.siny.2013.08.008
Saugstad, O. D., Robertson, N. J., & Vento, M. (2016). A critical review of the 2015 International Liaison Committee on Resuscitation treatment recommendations for resuscitating the newly born infant. Acta Paediatrica, 105(5), 442-444. doi:10.1111/apa.13358
Saugstad, O. D., Rootwelt, T., & Aalen, O. (1998). Resuscitation of asphyxiated newborn infants with room air or oxygen: an international controlled trial: the Resair 2 study. Pediatrics, 102(1), e1-e1.
Winter, J., Kattwinkel, J., Chisholm, C., Blackman, A., Wilson, S., & Fairchild, K. (2016). Ventilation of preterm infants during delayed cord clamping (VentFirst): a pilot study of feasibility and safety. American Journal of Perinatology. doi: 10.1055/s-0036-1584521
Wiswell, T. E., Gannon, C. M., Jacob, J., Goldsmith, L., Szyld, E., Weiss, K., ... & Caballero, C. L. (2000). Delivery room management of the apparently vigorous meconium-stained neonate: results of the multicenter, international collaborative trial. Pediatrics, 105(1), 1-7.
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