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Resuscitation of Asphyxiated Newborn Infants with Room Air Or Oxygen: an International Controlled Trial: the Resair 2 Study

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Resuscitation of Asphyxiated Newborn Infants with Room Air Or Oxygen: an International Controlled Trial: the Resair 2 Study Resuscitation of Asphyxiated Newborn Infants With Room Air or Oxygen: An International Controlled Trial: The Resair 2 Study Ola Didrik Saugstad, MD*; Terje Rootwelt, MD*; and Odd Aalen, PhD‡ ABSTRACT. Objective. Birth asphyxia represents a ment in agreement with the new proposal of the US Food serious problem worldwide, resulting in ;1 million and Drug Administration’s rules governing investiga- deaths and an equal number of serious sequelae annu- tional drugs and medical devices to permit clinical re- ally. It is therefore important to develop new and better search on emergency care without the consent of sub- ways to treat asphyxia. Resuscitation after birth asphyxia jects. The protocol was approved by the ethical traditionally has been carried out with 100% oxygen, and committees at each participating center. Entry criterion most guidelines and textbooks recommend this; how- was apnea or gasping with heart rate <80 beats per ever, the scientific background for this has never been minute at birth necessitating resuscitation. Exclusion cri- established. On the contrary, theoretic considerations in- teria were birth weight <1000 g, lethal anomalies, hy- dicate that resuscitation with high oxygen concentrations drops, cyanotic congenital heart defects, and stillbirths. could have detrimental effects. We have performed a Primary outcome measures were death within 1 week series of animal studies as well as one pilot study indi- and/or presence of hypoxic–ischemic encephalopathy, cating that resuscitation can be performed with room air grade II or III, according to a modification of Sarnat and just as efficiently as with 100% oxygen. To test this more Sarnat. Secondary outcome measures were Apgar score at thoroughly, we organized a multicenter study and hy- 5 minutes, heart rate at 90 seconds, time to first breath, pothesized that room air is superior to 100% oxygen time to first cry, duration of resuscitation, arterial blood when asphyxiated newborn infants are resuscitated. gases and acid base status at 10 and 30 minutes of age, Methodology. In a prospective, international, con- and abnormal neurologic examination at 4 weeks. trolled multicenter study including 11 centers from six The existing routines for resuscitation in each partici- countries, asphyxiated newborn infants with birth pating unit were followed, and the ventilation tech- weight >999 g were allocated to resuscitation with either niques described by the American Heart Association room air or 100% oxygen. The study was not blinded, and were used as guidelines aiming at a frequency of manual the patients were allocated to one of the two treatment ventilation of 40 to 60 breaths per minute. groups according to date of birth. Those born on even Results. Forms for 703 enrolled infants from 11 cen- dates were resuscitated with room air and those born on ters were received by the steering committee. All 94 pa- odd dates with 100% oxygen. Informed consent was not tients from one of the centers were excluded because of obtained until after the initial resuscitation, an arrange- violation of the inclusion criteria in 86 of these. There- fore, the final number of infants enrolled in the study was 609 (from 10 centers), with 288 in the room air group From the *Department of Pediatric Research, National Hospital, Oslo, Nor- and 321 in the oxygen group. way, and the ‡Section of Medical Statistics, University of Oslo, Oslo, Nor- Median (5 to 95 percentile) gestational ages were 38 way. (32.0 to 42.0) and 38 (31.1 to 41.5) weeks (NS), and birth Resuscitation of Asphyxiated Newborn Infants With Room Air or Oxygen: weights were 2600 (1320 to 4078) g and 2560 (1303 to 3900) The Second Multicenter Study (Resair 2) study group participants: S. Ramji, g (NS) in the room air and oxygen groups, respectively. MD, Department of Pediatrics, Maulana Azad Medical College, New Delhi, There were 46% girls in the room air and 41% in the India; S. F. Irani, MD, Department of Pediatrics, King Edward Memorial Hospital, Bombay, India; S. Jayam, MD, Kasturba Hospital for Women and oxygen group (NS). Mortality in the first 7 days of life Children, Madras, India; S. El-Meneza, MD, Faculty of Medicine for Girls, was 12.2% and 15.0% in the room air and oxygen groups, Al-Azhar University, Cairo, Egypt; A. Narang, MD, Department of Pediat- respectively; adjusted odds ratio (OR) 5 0.82 with 95% rics, Post Graduate Institute of Medical Education and Research, Chandi- confidence intervals (CI) 5 0.50–1.35. Neonatal mortality garh, India; M. Khasaba, MD, Department of Pediatrics, Mansoura, Egypt; was 13.9% and 19.0%; adjusted OR 5 0.72 with 95% CI 5 S. Sallab, MD, Department of Pediatrics, Mansoura, Egypt; E. A. Hernandez, 0.45–1.15. Death within 7 days of life and/or moderate or MD, Department of Pediatrics, Santo Thomas University Hospital, Manila, severe hypoxic–ischemic encephalopathy (primary out- Philippines; T. Talvik, MD, Children’s Hospital, Tartu University, Tartu, come measure) was seen in 21.2% in the room air group Estonia; P. Ilves, MD, Children’s Hospital, Tartu University, Tartu, Estonia; and in 23.7% in the oxygen group; OR 5 0.94 with 95% G. Samy Aly, PhD, Institute of Childhood Studies, Ain Shams University, 5 Cairo, Egypt; M. Vento, MD, Department of Pediatrics, Hospital Catolico, CI 0.63–1.40. “Casa de Salud” De Santa Ana, Valencia, Spain; F. Garcia-Sala, Department Heart rates did not differ between the two groups at of Pediatrics, Hospital Catolico, “Casa de Salud” De Santa Ana, Valencia, any time point and were (mean 6 SD) 90 6 31 versus Spain; R. Solberg, MD, Department of Pediatrics, Vestfold County Central 93 6 33 beats per minute at 1 minute and 110 6 27 versus Hospital, Tønsberg, Norway. 113 6 30 beats per minute at 90 seconds in the room air Resair 2 steering committee members: O. D. Saugstad, MD (Principal In- and oxygen groups, respectively. vestigator), T. Rootwelt, MD, O. Aalen, PhD, Department of Pediatric Apgar scores at 1 minute (median and 5 to 95 percen- Research, The National Hospital and Institute for Medical Statistics, Uni- tiles) were significantly higher in the room air group (5 [1 versity of Oslo, Oslo, Norway. to 6.7]) than in the oxygen group (4 [1 to 7]); however, at Received for publication Jan 20, 1998; accepted Apr 3, 1998. Reprint requests to (O.D.S.) Department of Pediatric Research, Rikshospi- 5 minutes there were no significant differences, with 8 (4 talet, 0027 Oslo, Norway. to 9) versus 7 (3 to 9). There were significantly more PEDIATRICS (ISSN 0031 4005). Copyright © 1998 by the American Acad- infants with very low 1-minute Apgar scores (<4) in the emy of Pediatrics. oxygen group (44.4%) than in the room air group (32.3%). http://www.pediatrics.org/cgi/content/full/102/1/Downloaded from www.aappublications.org/newse1 by guestPEDIATRICS on September Vol.29, 2021 102 No. 1 July 1998 1of7 There also were significantly more infants with 5-minute We were able to demonstrate that room air was as Apgar score <7 in the oxygen group (31.8%) than in the efficient as 100% O2 for resuscitation with regard to room air group (24.8%). There were no differences in acid normalization of heart rate, time to first breath, and base status or SaO2 during the observation period be- acid base status during the first 30 minutes of life. tween the two groups. Mean (SD) PaO2 was 31 (17) versus Apgar scores at 5 minutes were significantly higher 30 (22) mm Hg in cord blood in the room air and oxygen in the room air group. There were no significant groups, respectively (NS). At 10 minutes PaO2 was 76 (32) versus 87 (49) mm Hg (NS), and at 30 minutes, the values differences between the groups for neurologic symp- were 74 (29) versus 89 (42) mm Hg in the room air and toms or survival during the first week of life. The oxygen groups, respectively. small number of infants in that study precluded Median (95% CI) time to first breath was 1.1 (1.0–1.2) more extensive statistical analyses. Therefore, to test minutes in the room air group versus 1.5 (1.4 to 1.6) our hypothesis further, a larger sample size was minutes in the oxygen group. Time to the first cry also needed. Accordingly, a multicenter study was initi- was in mean 0.4 minute shorter in the room air group ated; the results are reported in this article. compared with the oxygen group. In the room air group, there were 25.7% so-called resuscitation failures (brady- METHODS cardia and/or central cyanosis after 90 seconds) that were The protocol was approved by the ethical committee for human switched to 100% oxygen after 90 seconds. The percent- investigation at each participating center. For practical reasons, age of resuscitation failures in the oxygen group was informed consent could not be obtained before enrollment. After 29.8%. resuscitation, informed consent for continued inclusion in the Conclusions. This study with patients enrolled pri- planned follow-up study was obtained from the parents. This marily from developing countries indicates that asphyx- arrangement was approved by the ethical committees and is in iated newborn infants can be resuscitated with room air agreement with the consensus statement from the coalition con- as efficiently as with pure oxygen. In fact, time to first ference of acute resuscitation and critical care researchers, and the breath and first cry was significantly shorter in room air- new proposal of the US Food and Drug Administration’s rules versus oxygen-resuscitated infants. Resuscitation with governing investigational drugs and medical devices to permit clinical research on emergency care without the consent of the 100% oxygen may depress ventilation and therefore de- subjects.8,9 lay the first breath.
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