TEXTBOOK OF Neonatal Resuscitation® 7th Edition

TEXTBOOK OF Neonatal Resuscitation® 7th Edition Textbook of Neonatal Resuscitation, 7th Edition Editor Gary M. Weiner, MD, FAAP Associate Editor Jeanette Zaichkin, RN, MN, NNP-BC Editor Emeritus John Kattwinkel, MD, FAAP Assistant Editors Anne Ades, MD, FAAP Christopher Colby, MD, FAAP Eric C. Eichenwald, MD, FAAP Kimberly D. Ernst, MD, MSMI, FAAP Marilyn Escobedo, MD, FAAP John Gallagher, MPH, RRT-NPS Louis P. Halamek, MD, FAAP Jessica Illuzzi, MD, MS, FACOG Vishal Kapadia, MD, MSCS, FAAP Henry C. Lee, MD, FAAP Linda McCarney, MSN, APRN, NNP-BC Patrick McNamara, MB, FRCPC Jeffrey M. Perlman, MB, ChB, FAAP Steven Ringer, MD, PhD, FAAP Marya L. Strand, MD, MS, FAAP Myra H. Wyckoff, MD, FAAP Educational Design Editor Jerry Short, PhD Managing Editors Rachel Poulin, MPH Wendy Marie Simon, MA, CAE Based on original text by Ronald S. Bloom, MD, FAAP Catherine Cropley, RN, MN Textbook of Neonatal Resuscitation, 7th Edition, eSim Cases: Anne Ades, MD, FAAP Kimberly D. Ernst, MD, MSMI, FAAP Jeanette Zaichkin, RN, MN, NNP-BC Published by the American Academy of Pediatrics 141 Northwest Point Blvd Elk Grove Village, IL Telephone: 847/434-4000 Facsimile: 847/228-1350 The recommendations in this publication and the accompanying materials do not indicate an exclusive course of treatment or serve as a standard of care. Variations, taking into account individual circumstances, nature of medical oversight, and local protocols, may be appropriate. Every effort has been made to ensure that contributors to the Neonatal Resuscitation Program materials are knowledgeable authorities in their fields. Readers are nonetheless advised that the statements and opinions expressed are provided as guidelines and should not be construed as official policy of the American Academy of Pediatrics or the American Heart Association. This material is made available as part of the professional education programs of the American Academy of Pediatrics and the American Heart Association. No endorsement of any product or service should be inferred or is intended. The American Academy of Pediatrics and the American Heart Association disclaim any liability or responsibility for the consequences of any actions taken in reliance on these statements or opinions. The American Academy of Pediatrics reserves the right to disclose personal information related to course completion of course participants/providers for administrative purposes such as to verify participation or classes taken or to validate the status of any Course Completion Card. In no event shall the American Academy of Pediatrics or American Heart Association have any liability for disclosure or use of information for such purposes or responsibility for the consequences of any actions taken in reliance on such information. Copyright © 2016 American Academy of Pediatrics and American Heart Association All rights reserved. No part of this publication or its accompanying materials may be reproduced, stored in a retrieval system, or transmitted in any form or by any means—electronic, mechanical, photocopying, recording, or otherwise–without prior permission from the publisher (locate title at and click on © Get Permissions; you may also fax the permissions editor at 847/434-8780 or e-mail ). First edition published 1987; second, 1990; third, 1994; fourth, 2000; fifth, 2006; sixth, 2011. Printed in the United States of America NRP323 ISBN: 978-1-61002-024-4 eBook: 978-1-61002-025-1 Library of Congress Control Number: /0416 1 2 3 4 5 6 7 8 9 10 Acknowledgments NRP Steering Committee Members Myra H. Wyckoff, MD, FAAP, Co-chair Steven Ringer, MD, PhD, FAAP, Co-chair Marilyn Escobedo, MD, FAAP, Co-chair Anne Ades, MD, FAAP Christopher Colby, MD, FAAP Liaison Representatives Eric C. Eichenwald, MD, FAAP AAP Committee on Fetus and Newborn John Gallagher, MPH, RRT-NPS American Association for Respiratory Care Jessica Illuzzi, MD, MS, FACOG American College of Obstetricians and Gynecologists Erich C. Eichenwald, MD, FAAP Kimberly D. Ernst, MD, MSMI, FAAP Vishal Kapadia, MD, FAAP Henry C. Lee, MD, FAAP Marya L. Strand, MD, MS, FAAP Linda McCarney, MSN, APRN, NNP-BC National Association of Neonatal Nurses Patrick McNamara, MB, FRCPC Canadian Paediatric Society Associated Education Materials for the Textbook of Neonatal Resuscitation, 7th Edition Instructor Toolkit, Jeanette Zaichkin, RN, MN, NNP-BC, Editor Instructor Course, Jeanette Zaichkin, RN, MN, NNP-BC, Editor; Vishal Kapadia, MD, MSCS, FAAP; Henry C. Lee, MD, FAAP; Taylor Sawyer, DO, MEd, FAAP; and Nicole K. Yamada, MD, FAAP, Contributors NRP Online Examination for Instructors, Jeanetet Zaichkin, RN, MN, NNP-BC NRP Online Examination for Providers, Steven Ringer, MD, PhD, FAAP, and Jerry Short, PhD, Editors NRP Reference Chart, Code Cart Cards, and Pocket Cards, Vishal Kapadia, MD, MSCS, FAAP, Editor NRP Key Behavioral Skills Poster, Louis P. Halamek, MD, FAAP, Editor NRP Equipment Poster, Jeanette Zaichkin, RN, MN, NNP-BC, Editor NRP App, Steven Ringer, MD, PhD, FAAP and Marya L. Strand, MD, MS, FAAP, Editors Neonatal Resuscitation Scenarios, Jeanette Zaichkin, RN, MN, NNP-BC, Editor; Myra H. Wyckoff, MD, FAAP; Vishal Kapadia, MD, MSCS, FAAP; Marya L. Strand, MD, MS, FAAP, Contributors The committee would like to express thanks to the following reviewers and contributors to this textbook: American Academy of Pediatrics Committee on Fetus and Newborn American Academy of Pediatrics Section on Bioethics International Liaison Committee on Resuscitation, Neonatal Delegation Jeffrey M. Perlman, MB, ChB, FAAP, Co-chair Jonathan Wylie, MD, Co-chair Errol R. Alden, MD, FAAP, AAP Board-appointed Reviewer Steven M. Schexnayder, MD, FAAP, AHA-appointed Reviewer Aviva L. Katz, MD, FAAP, AAP Committee on Bioethics Reviewer American Heart Association Allan R. de Caen, MD, Chair, AHA Pediatric Forum Farhan Bhanji, MD, MSc, Chair, AHA Educational Science and Programs Committee Photo Credits Benjamin Weatherston Gigi O’Dea, RN Mayo Foundation for Medical Education and Research Copy Editor Jill Rubino AAP Publications Staff Theresa Wiener Shannan Martin AAP Life Support Staff Kirsten Nadler, MS Rachel Poulin, MPH Wendy Marie Simon, MA, CAE Robyn Wheatley, MPH Thaddeus Anderson Kristy Crilly Gina Pantone Olyvia Phillips The committee would like to express thanks to the following contributors to the NRP 7th Edition: Pacific Lutheran University MediaLab, Tacoma, WA MultiCare Tacoma General Hospital, Tacoma, WA Taylor Sawyer, DO, MEd, FAAP Nicole K. Yamada, MD, FAAP Betty Choate, RNC-NIC Ronna Crandall, RNC-NIC Martine DeLisle, MSN, RNC Maria Luisa Flores, BSN, RNC Susan Greenleaf, BSN, RNC Susan Hope, RN Alta Kendall, ARNP, MSN, NNP-BC Mary Kuhns, NNP Gayle Livernash, RRT Aimee Madding, RN Cheryl Major, BSN, RNC-NIC Tracey McKinney, RN, CNS, DNP, MS, NNP Monica Scrudder, MSN, RNC-NIC Kerry Watrin, MD Raymond Weinrich, RN Stephanie K. Kukora, MD, FAAP, University of Michigan, Ann Arbor, MI NRP Instructor Development Task Force Anne Ades, MD, FAAP Eric C. Eichenwald, MD, FAAP Emer Finan, MB, DCH, Med, MRCPI Louis P. Halamek, MD, FAAP Steven Ringer, MD, PhD, FAAP Gary M. Weiner, MD, FAAP Myra H. Wyckoff, MD, FAAP Karen Kennally, BSN, RN Linda McCarney, MSN, RN, NNP-BC, EMT-P Wade Rich, RCP Kandi Zackery, BSN, RN, CEN, EMT-B Jeanette Zaichkin, RN, MN, NNP-BC Contents Preface Neonatal Resuscitation Program Provider Course Overview L E S S O N 1: Foundations of Neonatal Resuscitation��������������� 1 L E S S O N 2: Preparing for Resuscitation �������������������������������� 17 L E S S O N 3: Initial Steps of Newborn Care ��������������������������� 33 L E S S O N 4: Positive-Pressure Ventilation ������������������������������ 65 L E S S O N 5: Alternative Airways: Endotracheal Tubes and Laryngeal Masks����������������������������������������� 115 L E S S O N 6: Chest Compressions������������������������������������������� 163 L E S S O N 7: Medications ������������������������������������������������������� 183 L E S S O N 8: Post-resuscitation Care�������������������������������������� 213 L E S S O N 9: Resuscitation and Stabilization of Babies Born Preterm ����������������������������������������������������� 225 L E S S O N 10: Special Considerations �������������������������������������� 243 L E S S O N 11: Ethics and Care at the End of Life ������������������� 265 Appendix: Part 13: Neonatal Resuscitation 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care (Reprint) ��������������������������������������������������������������������������������������������������277 Index��������������������������������������������������������������������������������������������������� 305 Preface Being entrusted by parents to provide care for their newly born baby is both a privilege and an extraordinary responsibility. Since the first edition of the Textbook of Neonatal Resuscitation, the Neonatal Resuscitation Program® (NRP®) has helped more than 3 million health care providers fulfill this responsibility by providing the opportunity to acquire the knowledge and skills required to save newborn lives. The history and evolution of the NRP is fascinating and provides important lessons for health educators. A brief description is available on the NRP Web site and is well worth reading. Although the 7th edition includes several new recommendations, it emphasizes the same guiding principles that have been the foundation of the NRP for nearly 30 years. The original NRP textbook, published in 1987, was based on current practice, rational conjecture, and an informal consensus among experts. Beginning in 2000, the recommendations in the NRP textbook have been developed using a formal international consensus process. The American Academy of Pediatrics (AAP) and American Heart Association (AHA) partner in the evaluation of resuscitation science through the International Liaison Committee on Resuscitation (ILCOR). Researchers from the ILCOR Neonatal Task Force meet at regular intervals to review the science relevant to neonatal resuscitation. In a rigorous process, questions reflecting key knowledge gaps are identified, information scientists perform extensive literature searches, Neonatal Task Force members complete systematic reviews, the quality of scientific evidence is graded, and draft summary statements are prepared and published online for public comment. Finally, the members of the Task Force meet and discuss the summaries until a consensus on science is reached and treatment recommendations are formulated. The most recent statement, called the 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations (CoSTR), is based on a review of 27 neonatal resuscitation questions evaluated by 38 task force members representing 13 countries. After the meeting, each ILCOR member organization develops clinical guidelines based on the CoSTR document. Although ILCOR members are committed to minimizing international differences, each organization’s guidelines may vary based on geographic, economic, and logistic differences. The most recent guidelines for the United States are called the Neonatal Resuscitation 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. The guidelines and links to the systematic reviews supporting each recommendation are available online (http://pediatrics. This edition of the textbook includes 11 lessons. Two new lessons are dedicated to preparing for resuscitation (Lesson 2) and post- resuscitation care (Lesson 8). Similar to the 6th edition, the textbook emphasizes the importance of adequate preparation, effective ventilation, and teamwork. The details of how to implement ventilation corrective steps have been expanded and supplemented with additional illustrations. Nearly all drawings have been replaced with full-color photographs to enhance clarity. The order of lessons has been revised to reflect the increased emphasis on intubation before initiating chest compressions. Important changes in practice recommendations include new guidelines for the timing of umbilical cord clamping, the concentration of oxygen during resuscitation, the use of positive end-expiratory pressure (PEEP) and continuous positive airway pressure (CPAP) during and after resuscitation, the management of meconium-stained amniotic fluid, electronic cardiac (ECG) monitoring during resuscitation, the estimation of endotracheal tube insertion depth, and methods of thermoregulation for preterm (less than 32 weeks’ gestation) newborns. Within each lesson, new sections devoted to teamwork and frequently asked questions allow additional consideration of these topics in the context of the lesson content. The production of a textbook as complex as the Textbook of Neonatal Resuscitation cannot be accomplished without the effort of a team of dedicated and talented individuals. The ongoing partnership between the AAP, AHA, and ILCOR provides the infrastructure required to complete rigorous systematic reviews and develop evidence-based international guidelines. The members of the NRP Steering Committee, its liaison representatives, and volunteers spend countless hours preparing, reviewing, and debating each word and illustration in the textbook in an effort to provide learners with practical guidance even when the evidence is insufficient to make a definitive recommendation. Continued support from our strategic alliance partner, Laerdal Medical, has allowed the NRP to offer tools and learning technologies that challenge participants at every skill level. Working with Anne Ades (University of Pennsylvania), Kimberly Ernst (University of Oklahoma), and Jeanette Zaichkin (AAP), this creative partnership has developed a virtual learning environment that allows every NRP provider to participate in electronic simulation. Bringing the photographs and printed words to paper requires tremendous patience and attention to detail. Members of the NICU staff at St Joseph Mercy Hospital-Ann Arbor (Chris Adams, Jennifer Boyle, Anne Boyd, Ann Caid) and the University of Michigan (Anthony Iannetta, Wendy Kenyon, Shaili Rajput, Kate Stanley, Suzy Vesey), along with Jeanette Zaichkin, patiently modeled resuscitation skills for our unflappable medical photographer Benjamin Weatherston. Most of the live delivery room photographs were provided by Christopher Colby and his talented staff at the Mayo Clinic-Rochester. Diligent copyediting by Jill Rubino ensured consistency and clarity, while every detail involved in coordinating the planning, writing, production, and editing was expertly managed by Rachel Poulin. Every effective team requires strong leadership, and the NRP has been guided by a group of exceptional leaders. Jeffrey Perlman (Weill Medical College), Jonathan Wylie (James Cook University Hospital), and Myra Wyckoff (University of Texas Southwestern) provided steadfast leadership culminating in the international science and treatment consensus statements. Throughout the production cycle, NRP Steering Committee Cochairs Jane McGowan (Drexel University), Myra Wyckoff, Steven Ringer (Dartmouth-Hitchcock Medical Center), and Marilyn Escobedo (University of Oklahoma) patiently moderated spirited debate. Lou Halamek (Stanford University) challenged the committee to focus on competence rather than compliance and remain dedicated to innovation for the future. Jerry Short (University of Virginia) has been responsible for ensuring that the program’s educational design and assessment components remain consistent with adult learning principles and meet the needs of a wide range of learners. John Kattwinkel (University of Virginia) was a founding member of the NRP, served as the Steering Committee Cochair, edited the previous 4 editions of the textbook, and provided the words that expressed the nuances and complexities inherent in an international consensus statement. His advice and counsel have been critically important during the production of the 7th edition of the textbook. He is truly a giant in the world of neonatal resuscitation and continues to guide every aspect of the program with his calm demeanor and softly spoken wisdom. No acknowledgement would be complete without recognizing the tireless efforts of Jeanette Zaichkin and Wendy Simon. Jeanette’s creativity and boundless energy has been at the center of every recent NRP educational activity. Among her contributions, Jeanette is an accomplished instructor mentor, edits the NRP instructor materials, created the online Instructor Course, coedits the NRP Instructor Update, edits the NRP simulation scenarios, and has starred in every recent NRP educational video. She has been a partner in every phase of the 7th edition beginning with the first draft that was outlined at her dining room table. Jeanette carefully considers every sentence and instinctively understands the practical implications for readers. Oftentimes behind the scenes, Wendy Simon is the person who quietly ensures that everything related to the NRP and the ILCOR Neonatal Task Force works. She intuitively understands how to advocate for important causes, connect people, and facilitate complex international projects. Wendy’s conviction inspires the group to achieve more than anyone thought possible. Although she rarely accepts compliments, parents of children from Boston to Beijing can thank Wendy for their newborn’s healthy start. Gary M. Weiner, MD, FAAP Neonatal Resuscitation Program® Provider Course Overview Neonatal Resuscitation Scientific Guidelines The Neonatal Resuscitation Program® (NRP®) materials are based on the American Academy of Pediatrics (AAP) and American Heart Association (AHA) Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care of the Neonate (Circulation. 2015;132:S543-S560). A reprint of the Guidelines appears in the Appendix. Please refer to the Guidelines if you have any questions about the rationale for the current program recommendations. The Guidelines, originally published in October 2015, are based on the International Liaison Committee on Resuscitation (ILCOR) consensus on science statement. The evidence-based reviews prepared by members of ILCOR, which serve as the basis for both documents, can be viewed in the Web-based integrated guidelines site (https:// Level of Responsibility The NRP Provider Course consists of 11 lessons, and participants are required to complete all 11 lessons to receive an NRP Course Completion Card. Even though not all newborn health care providers can perform all steps in resuscitation, they may be called to help a team and need to be familiar with each step. Special Note: Neonatal resuscitation is most effective when performed by a designated and coordinated team. It is important for you to know the neonatal resuscitation responsibilities of team members who are working with you. Periodic practice among team members will facilitate coordinated and effective care of the newborn. NRP eSim NRP eSim is a new online neonatal resuscitation simulation exercise required for achieving NRP provider status with the 7th edition. The eSim methodology allows learners to integrate the NRP flow diagram steps in a virtual environment. For additional information on eSim, including Web browser requirements, visit Lesson Completion Successful completion of the online examination and eSim cases is required before learners attend the skills/simulation portion of the NRP course. Learners must attend the skills/simulation portion of the course within 90 days of completing the online examination and eSim cases. To successfully complete the course, participants must pass the online examination, complete eSim cases, demonstrate mastery of resuscitation skills in the Integrated Skills Station, and participate in simulated resuscitation scenarios, as determined by the course instructor(s). Upon successful completion of these requirements, participants are eligible to receive a Course Completion Card. Following the skills/ simulation portion of the course, learners will receive an e-mail with a link to complete an online course evaluation. Once the online course evaluation is completed, an electronic Course Completion Card will be available in the learner’s NRP Database profile. Completion Does Not Imply Competence The NRP is an educational program that introduces the concepts and basic skills of neonatal resuscitation. Completion of the program does not imply that an individual has the competence to perform neonatal resuscitation. Each hospital is responsible for determining the level of competence and qualifications required for someone to assume clinical responsibility for neonatal resuscitation. Standard Precautions The US Centers for Disease Control and Prevention has recommended that standard precautions be taken whenever risk of exposure to blood or bodily fluids is high and the potential infection status of the patient is unknown, as is certainly the case in neonatal resuscitation. All fluid products from patients (blood, urine, stool, saliva, vomitus, etc) should be treated as potentially infectious. Gloves should be worn when resuscitating a newborn, and the rescuer should not use his or her mouth to apply suction via a suction device. Mouth-to-mouth resuscitation should be avoided by having a resuscitation bag and mask or T-piece resuscitator always available for use during resuscitation. Masks and protective eyewear or face shields should be worn during procedures that are likely to generate droplets of blood or other bodily fluids. Gowns or aprons should be worn during procedures that probably will generate splashes of blood or other bodily fluids. Delivery rooms must be equipped with resuscitation bags, masks, laryngoscopes, endotracheal tubes, mechanical suction devices, and the necessary protective shields. LESSON 1 Foundations of Neonatal Resuscitation What you will learn ■ Why neonatal resuscitation skills are important ■ Physiologic changes that occur during and after birth ■ The format of the Neonatal Resuscitation Program® Flow Diagram ■ Communication and teamwork skills used by effective resuscitation teams Used with permission of Mayo Foundation for Medical Education and Research. 1 Antenatal counseling. Team briefing and equipment check. Birth 1 minute Labored breathing or persistent cyanosis? Yes The Neonatal Resuscitation Program (NRP®) will help you learn the cognitive, technical, and teamwork skills that you need to resuscitate and stabilize newborns. Although most newborns make the cardiorespiratory transition to extrauterine life without intervention, many will require assistance to begin breathing and a small number will require extensive intervention. After birth, approximately 4% to 10% of term and late preterm newborns will receive positive-pressure ventilation (PPV), while only 1 to 3 per 1,000 will receive chest compressions or emergency medications. Because the need for assistance cannot always be predicted, teams need to be prepared to provide these lifesaving interventions quickly and efficiently at every birth. During your NRP course, your team will learn how to evaluate a newborn, make decisions about what actions to take, and practice the steps involved in resuscitation. As you practice together in simulated cases, your resuscitation team will gradually build proficiency and speed. Why do newborns require a different approach to resuscitation than adults? Most often, adult cardiac arrest is a complication of trauma or existing heart disease. It is caused by a sudden arrhythmia that prevents the heart from effectively circulating blood. As circulation to the brain decreases, the adult victim loses consciousness and stops breathing. At the time of arrest, the oxygen and carbon dioxide (CO2) content of blood is usually normal. During adult cardiopulmonary resuscitation, chest compressions are used to maintain circulation until electrical defibrillation or medications restore cardiac function. In contrast, most newborns requiring resuscitation have a healthy heart. When a newborn requires resuscitation, it is usually caused by a problem with respiration leading to inadequate gas exchange. Respiratory failure may occur either before or after birth. Before birth, fetal respiratory function is performed by the placenta. If the placenta is functioning normally, oxygen is transferred from the mother to the fetus and CO2 is removed. When placental respiration fails, the fetus receives an insufficient supply of oxygen to support normal cellular functions and CO2 cannot be removed. The blood level of acid increases as cells attempt to function without oxygen and CO2 accumulates. Fetal monitoring may show a decrease in activity, loss of heart rate variability, and heart rate decelerations. If placental respiratory failure persists, the fetus will make a series of gasps followed by apnea and bradycardia. If the fetus is born in the early phase of respiratory failure, tactile stimulation may be sufficient to initiate spontaneous breathing and recovery. If the fetus is born in a later phase of respiratory failure, stimulation will not be sufficient and the newborn will require assisted ventilation for recovery. The most severely affected newborns may require chest compressions and epinephrine to allow the compromised heart muscle to restore circulation. At the time of birth, you may not know if the baby is in an early or a late phase of respiratory failure. After birth, respiratory failure occurs if the baby does not initiate or cannot maintain effective breathing effort. In either situation, the primary problem is a lack of gas exchange and the focus of neonatal resuscitation is effective ventilation of the baby’s lungs. Many concepts and skills are taught in this program. Establishing effective ventilation of the baby’s lungs during neonatal resuscitation is the single most important concept emphasized throughout the program. What happens during the transition from fetal to neonatal circulation? Understanding the basic physiology of the cardiorespiratory transition from intrauterine to extrauterine life will help you understand the steps of neonatal resuscitation. Fetal Respiration and Circulation Before birth, the fetal lungs do not participate in gas exchange. All of the oxygen used by the fetus is supplied from the mother by diffusion across the placenta. CO2 produced during fetal metabolism is transported across the placenta and removed by the mother’s lungs. The fetal lungs are expanded in utero, but the potential air sacs (alveoli) are filled with fluid instead of air. The pulmonary vessels that will carry blood to the alveoli after birth are tightly constricted and very little blood flows into them. In the placenta, oxygen diffuses from the mother’s blood into adjacent fetal blood vessels. The oxygenated fetal blood leaves the placenta through the umbilical vein. The umbilical vein travels through the liver, joins the inferior vena cava, and enters the right side of the heart. Because the pulmonary vessels are constricted, only a small fraction of blood entering the right side of the heart travels to the fetal lungs. Instead, most of the blood bypasses the lungs, crossing to the left side of the heart through an opening in the atrial wall (patent foramen ovale) or flowing from the pulmonary artery directly into the aorta through the ductus arteriosus (Figures 1.1A and 1.1B). Blood in the aorta supplies oxygen and nutrients to the fetal organs. The most highly oxygenated blood flows to the fetal brain and heart. Some of the blood in the aorta returns to the placenta through the 2 umbilical arteries to deliver CO2, receive more oxygen, and restart the circulation path. When blood follows this fetal circulation path and bypasses the lungs, it is called a right-to-left shunt. Superior vena cava Foramen ovale Ductus arteriosus Fluid- filled lung Right atrium Right ventricle Inferior vena cava Ductus venosus From placenta To placenta Umbilical vein Pulmonary artery Left ventricle Descending aorta Figure 1.1A. Fetal Circulation Path: Only a small amount of blood travels to the lungs. There is no gas exchange in the lung. Blood returning to the right side of the heart from the umbilical vein has the highest oxygen saturation. Umbilical arteries Ductus arteriosus Pulmonary artery Air- filled lung Right atrium Figure 1.1B. Transitional Circulation Path: The baby breathes, pulmonary resistance decreases and blood travels to the lungs. Gas exchange occurs in the lungs. Blood returning to the left side of the heart from the lungs has the highest oxygen saturation. Closed foramen ovale Right ventricle Inferior vena cava Left ventricle Descending aorta Transitional Circulation A series of physiologic changes occur after birth that culminates in a successful transition from fetal to neonatal circulation. Table 1-1 summarizes 3 important physiologic changes that occur during this transition. When the baby breathes and the umbilical cord is clamped, the newborn uses the lungs for gas exchange. Fluid is absorbed quickly from the alveoli and the lungs fill with air. The previously constricted pulmonary blood vessels begin to dilate so that blood can reach the alveoli where oxygen will be absorbed and CO2 will be removed (Figures 1.2A and 1.2B). Table 1-1. Transition From Fetal to Neonatal Respiration Change at Birth Result The baby breathes. The umbilical cord is clamped, separating the placenta from the baby. The newborn uses the lungs, instead of the placenta, for gas exchange. Fluid in the alveoli is absorbed. Air replaces fluid in the alveoli. Oxygen moves from the alveoli into the pulmonary blood vessels and CO2 moves into the alveoli to be exhaled. Air in the alveoli causes blood vessels in the lung to dilate. Pulmonary blood flow increases and the ductus arteriosus gradually constricts. The baby’s initial cries and deep breaths help to move fluid from the airways. In most circumstances, distention of the lungs with air provides sufficient oxygen (21%) to initiate relaxation of the pulmonary blood vessels. As blood levels of oxygen increase, the ductus arteriosus begins to constrict. Blood previously diverted through the foramen ovale and ductus arteriosus now flows from the right side of the heart into the lungs and the fetal “right-to-left shunt” gradually resolves. Oxygenated blood returning from the baby’s lungs travels to the left side of the heart and is pumped through the aorta to tissues throughout the body. Figure 1.2A. Air replaces fluid in the alveoli. Figure 1.2B. Pulmonary blood vessels dilate. Although the initial steps in a normal transition occur within a few minutes of birth, the entire process may not be completed for hours or even several days. For example, studies have shown it may take up to 10 minutes for a normal term newborn to achieve oxygen saturation greater than 90%. It may take several hours for alveolar fluid to be completely absorbed. Functional closure of the ductus arteriosus may not occur for 24 to 48 hours after birth, and complete relaxation of the pulmonary blood vessels does not occur for several months. Review Before birth, the alveoli in the fetal lungs are (collapsed)/ (expanded) and filled with (fluid)/(air). Before birth, oxygen is supplied to the fetus by (the placenta)/(the fetal lungs). After birth, air in the alveoli causes vessels in the baby’s lungs to (constrict)/(relax). Answers Before birth, the alveoli in the fetal lungs are expanded and filled with fluid. Before birth, oxygen is supplied to the fetus by the placenta. After birth, air in the alveoli causes vessels in the baby’s lungs to relax. How does a newborn respond to an interruption in normal transition? If there is an interruption in either placental function or neonatal respiration, gas exchange within tissues is decreased and the arterioles in the intestines, kidneys, muscles, and skin may constrict. A survival reflex maintains or increases blood flow to the heart and brain. This redistribution of blood flow helps to preserve function of these vital organs. If inadequate gas exchange continues, the heart begins to fail and blood flow to all organs decreases. The lack of adequate blood perfusion and tissue oxygenation interferes with cellular function and may lead to organ damage. Table 1-2 summarizes some of the clinical findings associated with an interruption in normal transition. Table 1-2. Clinical Findings of Abnormal Transition What is the Neonatal Resuscitation Program Flow Diagram? The NRP Flow Diagram describes the steps that you will follow to evaluate and resuscitate a newborn. It is divided into 5 blocks beginning with birth and the initial assessment. Throughout the diagram, diamonds indicate assessments and rectangles show actions that may be required. Although it is important to work quickly and efficiently, you must ensure that you have adequately performed the steps of each block before moving on to the next block. Assessments are repeated at the end of each block and will determine if you need to proceed. The details of each block are described in subsequent lessons. • Initial Assessment: Determine if the newborn can remain with the mother or should be moved to a radiant warmer for further evaluation. • Airway (A): Perform the initial steps to establish an open Airway and support spontaneous respiration. • Breathing (B): Positive-pressure ventilation is provided to assist Breathing for babies with apnea or bradycardia. Other interventions (continuous positive airway pressure [CPAP] or oxygen) may be appropriate if the baby has labored breathing or low oxygen saturation. Take a moment to familiarize yourself with the layout of the NRP Flow Diagram. Antenatal counseling. Team briefing and equipment check. Birth 1 minute Labored breathing or persistent cyanosis? Yes 9