Resuscitation Of Newborn Infants Research Articles

2023 American Heart Association and American Academy of Pediatrics Focused Update on Neonatal Resuscitation: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

This 2023 focused update to the neonatal resuscitation guidelines is based on 4 systematic reviews recently completed under the direction of the International Liaison Committee on Resuscitation Neonatal Life Support Task Force. Systematic reviewers and content experts from this task force performed comprehensive reviews of the scientific literature on umbilical cord management in preterm, late preterm, and term newborn infants, and the optimal devices and interfaces used for administering positive-pressure ventilation during resuscitation of newborn infants. These recommendations provide new guidance on the use of intact umbilical cord milking, device selection for administering positive-pressure ventilation, and an additional primary interface for administering positive-pressure ventilation.

2023 American Heart Association and American Academy of Pediatrics Focused Update on Neonatal Resuscitation: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.

This 2023 focused update to the neonatal resuscitation guidelines is based on 4 systematic reviews recently completed under the direction of the International Liaison Committee on Resuscitation Neonatal Life Support Task Force. Systematic reviewers and content experts from this task force performed comprehensive reviews of the scientific literature on umbilical cord management in preterm, late preterm, and term newborn infants, and the optimal devices and interfaces used for administering positive-pressure ventilation during resuscitation of newborn infants. These recommendations provide new guidance on the use of intact umbilical cord milking, device selection for administering positive-pressure ventilation, and an additional primary interface for administering positive-pressure ventilation.

Oxygenation of the newborn. The impact of one molecule on newborn lives.

Hypoxanthine is a purine metabolite which increases during hypoxia and therefore is an indicator of this condition. Further, when hypoxanthine is oxidized to uric acid in the presence of xanthine oxidase, oxygen radicals are generated. This was the theoretical basis for suggesting and studying, beginning in the 1990s, resuscitation of newborn infants with air instead of the traditional 100% O2. These studies demonstrated a 30% reduction in mortality when resuscitation of term and near term infants was carried out with air compared to pure oxygen. The mechanism for this is not fully understood, however the hypoxanthine-xanthine oxidase system increases oxidative stress and plays a role in regulation of the perinatal circulation. Further, hyperoxic resuscitation inhibits mitochondrial function, and one reason may be that genes involved in ATP production are down-regulated. Thus, the study of one single molecule, hypoxanthine, has contributed to the global prevention of an estimated 2-500,000 annual infant deaths.

Evidence for vasopressors during cardiopulmonary resuscitation in newborn infants.

An estimated 0.1% of term infants and up to 15% of preterm infants (2-3 million worldwide) need extensive resuscitation, defined as chest compression and 100% oxygen with or without epinephrine in the delivery room. Despite these interventions, infants receiving extensive resuscitation in the DR have a high incidence of mortality and neurologic morbidity. Successful resuscitation from neonatal cardiac arrest requires the delivery of high-quality chest compression using the most effective vasopressor with the optimal dose, timing, and route of administration during CPR. Current neonatal resuscitation guidelines recommend administration of epinephrine once CPR has started at a dose of 0.01-0.03 mg/kg preferably given intravenously, with repeated doses every 3-5 min until return of spontaneous circulation. This review examines the current evidence for epinephrine and alternative vasopressors during neonatal cardiopulmonary resuscitation.

Successful Resuscitation in a Model of Asphyxia and Hemorrhage to Test Different Volume Resuscitation Strategies. A Study in Newborn Piglets After Transition.

Background: Evidence for recommendations on the use of volume expansion during cardiopulmonary resuscitation in newborn infants is limited.Objectives: To develop a newborn piglet model with asphyxia, hemorrhage, and cardiac arrest to test different volume resuscitation on return of spontaneous circulation (ROSC). We hypothesized that immediate red cell transfusion reduces time to ROSC as compared to the use of an isotonic crystalloid fluid.Methods: Forty-four anaesthetized and intubated newborn piglets [age 32 h (12–44 h), weight 1,220 g (1,060–1,495g), Median (IQR)] were exposed to hypoxia and blood loss until asystole occurred. At this point they were randomized into two groups: (1) Crystalloid group: receiving isotonic sodium chloride (n = 22). (2) Early transfusion group: receiving blood transfusion (n = 22). In all other ways the piglets were resuscitated according to ILCOR 2015 guidelines [including respiratory support, chest compressions (CC) and epinephrine use]. One hour after ROSC piglets from the crystalloid group were randomized in two sub-groups: late blood transfusion and infusion of isotonic sodium chloride to investigate the effects of a late transfusion on hemodynamic parameters.Results: All animals achieved ROSC. Comparing the crystalloid to early blood transfusion group blood loss was 30.7 ml/kg (22.3–39.6 ml/kg) vs. 34.6 ml/kg (25.2–44.7 ml/kg), Median (IQR). Eleven subjects did not receive volume expansion as ROSC occurred rapidly. Thirty-three animals received volume expansion (16 vs. 17 in the crystalloid vs. early transfusion group). 14.1% vs. 10.5% of previously extracted blood volume in the crystalloid vs. early transfusion group was infused before ROSC. There was no significant difference in time to ROSC between groups [crystalloid group: 164 s (129–198 s), early transfusion group: 163 s (162–199 s), Median (IQR)] with no difference in epinephrine use.Conclusions: Early blood transfusion compared to crystalloid did not reduce time to ROSC, although our model included only a moderate degree of hemorrhage and ROSC occurred early in 11 subjects before any volume resuscitation occurred.

Feasibility and safety of intact cord resuscitation in newborn infants with congenital diaphragmatic hernia (CDH)

BackgroundStarting resuscitation before clamping the umbilical cord at birth may progressively increase pulmonary blood flow while umbilical venous blood flow is still contributing to maintenance of oxygenation and left ventricle preload. ObjectiveTo evaluate the feasibility, safety, and effects of intact cord resuscitation (ICR) on cardiorespiratory adaptation at birth in newborn infants with CDH. Study designProspective, observational, single-center pilot study. MethodsPhysiologic variables and outcomes were collected prospectively in 40 consecutive newborn infants with an antenatal diagnosis of isolated CDH. ResultsInfants were managed with immediate cord clamping (ICC group) from 1/2012 to 5/2014 or the cord was clamped after initiation of resuscitation maneuvers (ICR group) from 6/2014 to 4/2016 (20 in each group). Ante- and postnatal markers of CDH severity were similar between groups. Resuscitation before cord clamping was possible for all infants in the ICR group. No increase in maternal or neonatal adverse events was observed during the period of ICR. The pH was higher and the plasma lactate concentration was significantly lower at one hour after birth in the ICR than in the ICC group (pH=7.17±0.1 vs 7.08±0.2; lactate=3.6±2.3 vs 6.6±4.3mmol/l, p<0.05). Mean blood pressure was significantly higher in the ICR than in the ICC group at H1 (52±7.7 vs 42±7.5mmHg), H6 (47±3.9 vs 40±5.6mmHg) and H12 (44±2.9 vs 39±3.3mmHg) (p<0.05). ConclusionCommencing resuscitation and initiating ventilation while the infant is still attached to the placenta is feasible in infants with CDH. The procedure may support the cardiorespiratory transition at birth in infants with CDH.

Oxygen for the resuscitation of newborn infants

Oxygen for the resuscitation of newborn infants

Geburtshilfliche Anästhesie – Erstversorgung und Reanimation von Neugeborenen

Successful resuscitation of newborn infants depends on adequate preparation, exact evaluation and prompt initiation of support according to the recently updated recommendations by trained personnel. The key step in postnatal adaptation is the initiation of breathing with a subsequent increase in pulmonary blood flow and pulmonary gas exchange. Therefore, in compromised newborn infants, adequate ventilation is the most important step in cardiopulmonary resuscitation. Ventilation should be initiated with room air in term infants and with low concentrations of supplemental oxygen in preterm infants. Subsequently, oxygen supplementation should always be guided by pulse oximetry. Chest compressions are only effective if adequate ventilation has been ensured. The compression ventilation ratio remains 3:1. The prevention of heat loss and maintaining a normal body temperature by adequate measures is an essential part of the care for healthy as well as asphyxiated infants. Therapeutic hypothermia should only be initiated after successful resuscitation and consultation with the regional neonatal intensive care unit.

Resuscitation of newborn infants: from oxygen to room air

Resuscitation of newborn infants: from oxygen to room air

Newborn resuscitation: should we oxygenate or not?

EDITORIAL FOCUSNewborn resuscitation: should we oxygenate or not?Ola Didrik SaugstadOla Didrik SaugstadPublished Online:01 Oct 2008https://doi.org/10.1152/ajpheart.00880.2008This is the final version - click for previous versionMoreSectionsPDF (39 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat how should we oxygenate newborn and infants suffering from hypoxia and ischemia? Is it harmful to use 100% O2? It may seem odd to question a practice that has been carried out for so long, seemingly without any adverse effects. The case is, however, that after the practice of routinely using 100% O2 for newborn resuscitation was examined, many serious potentially harmful effects have to date been described (for review, see Ref. 13).Fabian et al. (1) add new information to the topic of how asphyxiated newborns should be reoxygenated (1). By inducing unilateral brain ischemia and hypoxia in newborn (7 day) rats, they showed that cerebral blood flow in the ischemic cortex declined following resuscitation with 100% O2 but not with ambient air. These findings in hyperoxic animals were accompanied by a reduction in perivascular production of nitric oxide (NO). Intraperitoneal injection with tetrahydrobiopterin (BH4) increased cerebral blood flow during hyperoxic resuscitation. This was followed by increased perivascular NO and reduced perivascular O2−. The authors suggest that hyperoxia uncouples perivascular NO synthase (NOS), probably endothelial NOS, leading to a reduced NO and increased O2− production. An injection of apocyanin, which is an inhibitor of NADPH oxidase, also increased NO and reduced O2−, indicating that an oxidative burst may be of importance in neonatal hypoxic-ischemic brain injury.This study confirms that a hyperoxic resuscitation of newborns may reduce the restoration of cerebral blood flow and therefore may be detrimental. But it also indicates that BH4 and perhaps also apocyanin should be interesting agents to test out in similar models to prevent such potentially harmful effects.For many reasons one should be careful drawing firm conclusions from newborn rats to newborn human infants. One major difference between birth asphyxia and the present model is that in the former the partial carbon dioxide tension of arterial blood (PaCO2) is elevated. Restoration of cerebral blood flow during reoxygenation differs whether it starts out with a high or as in the present study a relatively low PaCO2 (16). In resuscitated newborns infants, we also know that the time of reoxygenation often does not last more than a few minutes. A reoxygenation time of 2 h as in the study of Fabian et al. (1) therefore may not be relevant for newborns. On the other hand, such a long exposure to hyperoxia is not rare in the intensive care of children outside the immediate newborn period. A recent study by Koch et al. (8) showed that postischemic and posthypoxic hyperoxic exposure may have shocking effects on the brain. These authors found a dramatic augmented cerebral injury in 2-wk-old mice exposed to unilateral carotid ligation and hypoxia already after 30 min of hyperoxic-reoxygenation compared with reoxygenation with ambient air.There are now numerous experimental studies showing that hyperoxic resuscitation of newborn animals leads to inflammation and necrosis/apoptosis in the brain as well as in other organs (10, 13). Clinical studies as well show that hyperoxic compared with normoxic reoxygenation of newborn infants leads to tissue injury, for instance, in the myocardium and kidney (19). Even a brief exposure of hyperoxia after birth seems to trigger long-term elevation—at least several weeks—of oxidative stress (18). The consequence of this for growth and development is not understood. And more importantly, a recent meta-analysis including more than 2,000 newborn infants shows a 30% reduction in neonatal mortality when resuscitation was carried out with 21% instead of 100% O2 (15). This is an important finding because 5% of all newborn infants are in need of some ventilatory stimulation after birth and 1% need more extensive respiratory and ventilatory support (6). This means that in the United States 200,000 newborn infants need some kind of resuscitation every year. A reduction of mortality from 3.9% to 1.2% in these children, as found in European data (15), indicates that thousands of lives can be saved in the United States alone by avoiding the use of 100% O2 for newborn resuscitation. Based on these findings, more and more countries are therefore changing their guidelines and practice, starting with a low instead of a high inspired O2 fraction when newborn infants are in need of resuscitation. The study by Fabian et al. (1), as well as the one of Koch et al. (8), strongly indicates that also in children outside the newborn period hyperoxic-reoxygenation should be avoided. However, in this age group, clinical studies are lacking and are absolutely needed.There is in my opinion strong reasons that the results of Fabian et al. (1) have clinical relevance. Already by the mid-1990s, Lundstrøm et al. (9) showed that preterm infants exposed to a brief period of hyperoxia after birth had cerebral vasoconstriction as long as 2 h later.The understanding that a brief exposure of hyperoxia at birth may be detrimental has slowly evolved during more than 50 years in two lines of research. In 1953, Gerschman et al. (3) formulated the hypothesis that O2 is toxic because it generates O2 free radicals. The seminal observation by McCord and Fridovich (11) 14 years later that the xanthine/xanthine oxidase system generates O2 radicals continued this line of research. The other line of evidence was accumulated in the 1960s when it was shown that purine metabolites accumulate in isolated hypoxic kidney and myocardium (5) and in the 1970s when we found that hypoxanthine, the precursor of xanthine, accumulates in the body fluids of hypoxic newborn babies (12). This is the background of so-called reoxygenation or reperfusion injury (4, 14).One consequence of this understanding has been to reduce the O2 supplementation when hypoxic tissues or organs are reoxygenated. In the newborn this seems to be a promising strategy, and the O2 load to newborn and premature infants has been dramatically lowered the last decade or so (13). It is surprising that this has not yet to any extent been tested out in older children or adults.A second consequence of this line of research has been to find antioxidants that may reduce the harm inflicted by hypoxia-reoxygenation injury. So far the magic bullet has in my opinion not yet been found. One major issue is that reactive O2 species seem to have important regulatory functions in the newborn period, so care should be exercised giving antioxidants (7). It still is not well understood as shown by Friel et al. (2) why there is increased oxidative stress the first months of life.The study by Fabian et al. (1) opens for new therapeutic revenues, suggesting a different approach of therapy, administrating BH4. BH4 is synthesized from GTP and is a naturally occurring essential cofactor of phenylalanine, tyrosine, and tryptophan hydroxylases and is also essential for synthesis of NO by NOS. The lack of BH4 therefore may affect both catecholamine and NOS. BH4 is both a growth factor and a general neuroprotective factor (17). BH4 is reduced during oxidative stress; replenishment of this factor may therefore reduce O2 radical production. Yamashiro et al. (20) have for instance shown that BH4 lessens ischemia-reperfusion injury in isolated perfused rat hearts.The study by Fabian et al. (1) not only confirms that hyperoxic-reoxygenation of newborn hypoxic animals is detrimental, it also points to a pharmacological approach that may more specifically reduce O2 free radical production in a stage when this may be deleterious. This study is an example how experimental studies may lead the way from the laboratory to the bedside.REFERENCES1 Fabian HR, Perez-Polo J, Kent TA. Perivascular nitric oxide and superoxide in neonatal cerebral hypoxia-ischemia. Am J Physiol Heart Circ Physiol (August 1, 2008). doi: 10.1152/ajpheart.00301.2007.Link | ISI | Google Scholar2 Friel JK, Friesen RW, Harding SV, Roberts LJ. Evidence of oxidative stress in full-term healthy infants. Pediatr Res 56: 878–882, 2004.Crossref | PubMed | ISI | Google Scholar3 Gerschman R, Gilbert DL, Nye SW, Dwyer P, Fenn WO. Oxygen poisoning and x-irradiation: a mechanism in common. Science 119: 623–626, 1954.Crossref | PubMed | ISI | Google Scholar4 Granger DN, Rutili G, McCord JM. Superoxide radicals in feline intestinal ischemia. Gastroenterology 81: 22–29, 1981.Crossref | PubMed | ISI | Google Scholar5 Imai S, Riley AL, Berne RM. Effect of ischemia on adenine nucleotides in cardiac and skeletal muscles. Circ Res 15: 443–450, 1964.Crossref | PubMed | ISI | Google Scholar6 International Liaison Committee on Resuscitation. The International Liaison Committee on Resuscitation (ILCOR) consensus on science with treatment recommendations for pediatric and neonatal patients: neonatal resuscitation. Pediatrics 117: e978–e988, 2006.Crossref | PubMed | ISI | Google Scholar7 Jankov RP, Negus A, Tanswell AK. Antioxidants as therapy in the newborn: some words of caution. Pediatr Res 50: 681–687, 2001.Crossref | PubMed | ISI | Google Scholar8 Koch JD, Miles DK, Gilley JA, Yang CP, Kernie SG. Brief exposure to hyperoxia depletes the glial progenitor pool and impairs functional recovery after hypoxic-ischemic brain injury. J Cereb Blood Flow Metab 28: 1294–1306, 2008.Crossref | PubMed | ISI | Google Scholar9 Lundstrøm KE, Pryds O, Greisen G. Oxygen at birth and prolonged cerebral vasoconstriction in preterm infants. Arch Dis Child Fetal Neonatal Ed 73: F81–F86, 1995.Crossref | PubMed | ISI | Google Scholar10 Markus T, Hansson S, Amer-Wåhlin I, Hellström-Westas L, Saugstad OD, Ley D. Cerebral inflammatory response after fetal asphyxia and hyperoxic resuscitation in newborn sheep. Pediatr Res 62: 71–77, 2007.Crossref | PubMed | ISI | Google Scholar11 McCord JM, Fridovich I. The reduction of cytochrome c by milk xanthine oxidase. J Biol Chem 243: 5753–5760, 1968.Crossref | PubMed | ISI | Google Scholar12 Saugstad OD. Hypoxanthine as a measurement of hypoxia. Pediatr Res 9: 158–161, 1975.Crossref | PubMed | ISI | Google Scholar13 Saugstad OD. Optimal oxygenation at birth and in the neonatal period. Neonatology 91: 319–322, 2007.Crossref | PubMed | ISI | Google Scholar14 Saugstad OD, Aasen AO. Plasma hypoxanthine concentrations in pigs. A prognostic aid in hypoxia. Eur Surg Res 12: 123–129, 1980.Crossref | PubMed | ISI | Google Scholar15 Saugstad OD, Ramji S, Soll RF, Vento M. Resuscitation of newborn infants with 21% or 100% oxygen: an updated systematic review and meta-analysis. Neonatology 94: 176–182, 2008.Crossref | PubMed | ISI | Google Scholar16 Solås AB, Kalous P, Saugstad OD. Reoxygenation with 100 or 21% oxygen after cerebral hypoxemia-ischemia-hypercapnia in newborn piglets. Biol Neonate 85: 105–111, 2004.Crossref | PubMed | Google Scholar17 Thöny B, Auerbach G, Blau N. Tetrahydrobiopterin biosynthesis, regeneration and functions. Biochem J 347: 1–14, 2000.Crossref | PubMed | ISI | Google Scholar18 Vento M, Asensi M, Sastre J, García-Sala F, Pallardó FV, Viña J. Resuscitation with room air instead of 100% oxygen prevents oxidative stress in moderately asphyxiated term neonates. Pediatrics 107: 642–647, 2001.Crossref | PubMed | ISI | Google Scholar19 Vento M, Sastre J, Asensi MA, Viña J. Room-air resuscitation causes less damage to heart and kidney than 100% oxygen. Am J Respir Crit Care Med 172: 1393–1398, 2005.Crossref | PubMed | ISI | Google Scholar20 Yamashiro S, Noguchi K, Matsuzaki T, Miyagi K, Nakasone J, Sakanashi M, Koja K, Sakanshi M. Beneficial effect of tetrahydrobiopterin on ischemia-reperfusion injury in isolated perfused rat hearts. J Thorac Cardiovasc Surg 124: 775–784, 2002.Crossref | PubMed | ISI | Google ScholarAUTHOR NOTESAddress for reprint requests and other correspondence: O. D. Saugstad, Dept. of Pediatric Research, Rikshospitalet, 0027 Oslo, Norway (e-mail: [email protected]) Download PDF Back to Top Next FiguresReferencesRelatedInformation Cited ByAdditional Clinical Aspects of Developmental Physiology and Clinical Care2 February 2018Pulse Oximetry in Very Low Birth Weight InfantsClinics in Perinatology, Vol. 41, No. 4Reevaluating Reference Ranges of Oxygen Saturation for Healthy Full-term Neonates Using Pulse OximetryPediatrics & Neonatology, Vol. 55, No. 6Additional Clinical Aspects of Developmental Physiology31 July 2013Oxygen in Health and Disease: Regulation of Oxygen Homeostasis-Clinical ImplicationsPediatric Research, Vol. 65, No. 3 More from this issue > Volume 295Issue 4October 2008Pages H1371-H1372 Copyright & PermissionsCopyright © 2008 by the American Physiological Societyhttps://doi.org/10.1152/ajpheart.00880.2008PubMed18708440History Published online 1 October 2008 Published in print 1 October 2008 Metrics

Evaluation of peak inspiratory pressure, tidal volume and respiratory rate during ventilation of premature lambs using a self-inflating bag

To evaluate the peak inspiratory pressure, tidal volume and respiratory rate achieved during manual ventilation of premature lambs, using a self-inflating bag. In this descriptive, experimental study, five pairs of physicians, selected at random among 35 neonatologists working at a neonatal intensive care unit and with experience in the resuscitation of newborn infants, ventilated five intubated premature lambs using a self-inflating bag. Pressure and flow monitor signals were passed through a transducer and digitized for recording and analysis. Tidal volume and pressure curves were obtained from the integral of flow rate, at peak, during the last 50 seconds of every fifth minute, and analyzed. Median pressure was 39.8 (IQ(25-75%) 30.2-47.2) cmH(2)O; being below 20 in 1.1% of cases and above 40 in 49.1%. Seven out of 10 physicians produced more than six pressure peaks of over 40 cmH(2)O. Median tidal volume/kg was 17.8 (IQ(25-75%) 14.1-22.4) mL, being below 5 mL in 0.1% of cases and greater than or equal to 20 mL in 37.7%. All of the physicians propelled five or more ventilation cycles with tidal volume/kg of 20 mL or more. Respiratory rate was between 30 and 60 cycles/minute in 65.9% of cases, being below 30 in 6.8% of cases and over 60 in 27.3% of cases. There was major variation in peak inspiratory pressure and tidal volume/kg values, which were in many cases elevated, attaining levels that habitually cause biotrauma, while respiratory rates were adequate in the majority of cases.

Resuscitation of newborn infants with 100% oxygen or air: A systematic review and meta-analysis

Resuscitation of newborn infants with 100% oxygen or air: A systematic review and meta-analysis

Resuscitation of newborn infants

Methods of resuscitation of neonates are generally based on expert opinions and intuition, and relate to guidelines for adults or paediatric resuscitation. Results of multicentre randomised trials have, however, recently exposed some commonly used methods as ineffective. As such, I found comparing the conclusions of the meta-analysis published on Oct 9 (p 1329)1 on this topic with the one2 previously published by the same authors in the Cochrane Database confusing—the objectives, methods, eligibility criteria, exclusion criteria, number of identified eligible studies, number of patients enrolled in all studies and counted for various outcomes, and effect estimates of the various outcomes were similar, but the conclusions different.

Resuscitation of newborn infants

Resuscitation of newborn infants

Translating teamwork behaviours from aviation to healthcare: development of behavioural markers for neonatal resuscitation.

Improving teamwork in healthcare may help reduce and manage errors. This paper takes a step toward that goal by (1) proposing a set of teamwork behaviours, or behavioural markers, for neonatal resuscitation; (2) presenting a data form for recording observations about these markers; and (3) comparing and contrasting different sets of teamwork behaviours that have been developed for healthcare. Data from focus groups of neonatal providers, surveys, and video recordings of neonatal resuscitations were used to identify some new teamwork behaviours, to translate existing aviation team behaviours to this setting, and to develop a data collection form. This behavioural marker audit form for neonatal resuscitation lists and defines 10 markers that describe specific, observable behaviours seen during the resuscitation of newborn infants. These markers are compared with those developed by other groups. Future research should determine the relations among these behaviours and errors, and test their usefulness in measuring the impact of team training interventions.

Is 100% oxygen necessary for the resuscitation of newborn infants?

This paper reproduces in detail the debate ‘pro-and-con’ regarding the use of 100% oxygen or room air in the resuscitation of the asphyxiated newly born infants, celebrated in Oslo at the 2002 European Association of Perinatal Medicine (EAPM) meeting, in which both co-authors participated as featured speakers. The authors describe their arguments which are based on medical tradition, clinical experience, basic science, and prospective randomized and pseudo-randomized clinical studies that have been reported in the past years. Both authors stress the importance of the long-term consequences of the use of high oxygen concentrations in the perinatal period and conclude that there is a need for further research in the way of ample prospective randomized clinical trials.

Resuscitation of newborn infants with room air or oxygen

Oxygen is a toxic agent and a critical approach regarding its use during resuscitation at birth is developing. Animal data indicate that room air is efficient for newborn resuscitation. Three clinical studies have established that normal ventilation is delayed after oxygen resuscitation. Oxidative stress is augmented for several weeks in infants exposed to oxygen at birth – the long-term implications of these observations remain unclear. There are limited data regarding the use of room air during complicated resuscitations, i.e. in meconium aspiration, the severely asphyxiated infant and in the preterm infant. Thus, it is necessary to continue ongoing rigorous examination of the long-accepted practice of oxygen administration during neonatal resuscitation.

Magnetic resonance and near infrared spectroscopy for investigation of perinatal hypoxic-ischaemic brain injury.

Hypoxic-ischaemic injury to the brain is an important cause of perinatal death and seems to be the commonest cause of permanent neurodevelopmental disability in newborn infants who survive after intensive care. If this type of brain injury is to be prevented and treatment put on a rational basis, non-invasive methods are required for defining its mechanisms. This review has considered two such methods: magnetic resonance spectroscopy and near infrared spectroscopy. Magnetic resonance spectroscopy is used to measure, in brain tissue, the concentrations of the 'high energy' phosphorus metabolites that are dependent for their synthesis on the processes of oxidative phosphorylation. Intracellular pH can also be measured. Normal maturational changes in the brain have been defined and abnormalities detected in a range of conditions where hypoxic-ischaemic injury was suspected to have occurred. In laboratory animals the acute effects of curtailment of oxygen supply to the brain ('primary' energy failure) have been observed, and the effects of two commonly used treatments, infusions of sodium bicarbonate and glucose, have been tested. After resuscitation of newborn infants from severe intrapartum asphyxia, a latent period has often been noted before energy failure became detectable. This 'secondary' energy failure is due to a variety of damaging reactions initiated by the acute hypoxicischaemic episode and reperfusion of the brain. It is possible that in the future irreversible injury to brain cells following the episode may be prevented or ameliorated by the prompt use of cerebroprotective agents. The extent of abnormalities detected by magnetic resonance spectroscopy has prognostic implications: evidence of severe energy failure in the first days of life was regularly associated with subsequent death or with severe neurodevelopmental impairments. Many technical developments in magnetic resonance spectroscopy are under way, particularly employing proton (1H) spectroscopy, which will allow the intracerebral concentrations of a wide range of metabolites, including neurotransmitters, to be measured. The combination of spectroscopy with magnetic resonance imaging will permit quantitative data to be obtained from selected volumes within the brain. Near infrared spectroscopy is used to make observations at the cotside of the intracerebral concentrations of the chromophores oxyhaemoglobin, deoxyhaemoglobin, and oxidised cytochrome aa3, and it therefore provides information complementary to that obtained by magnetic resonance spectroscopy. Measurements can also be made of cerebral blood flow, cerebral blood volume, and other haemodynamic indices; in addition, the rea

Resuscitation of the Newborn Infant and Related Emergency Procedures in the Perinatal Center Special Care Nursery: Principles and Practice

In 1956 the Special Committee on Infant Mortality of the New York Medical Society published its first report, Resuscitation of Newborn Infants. The aims of the committee were to study methods of preventing perinatal deaths from asphyxia and ways by which its complicating effects could best be combated in those infants who survive. Since that report, three editions of a more comprehensive book have been published with these goals in mind. The third edition is a collaborative effort to coordinate information that may serve to prevent morbidity and mortality in the perinatal period. The goal was to present more than merely the mechanics of the immediate resuscitation procedures. In the first chapters, the authors have discussed factors that influence pregnancy and delivery, with an emphasis on preventive medicine. They stressed the need for close cooperation between obstetrician, anesthesiologist, pathologist, geneticist, and pediatrician to understand all of the potential influences in

RESUSCITATION OF THE NEWBORN INFANT

IN ORDER to initiate respiration, the newborn infant must be able to overcome a resistance to expansion of the lungs which is often as high as 30 cm. H2O. The lungs will remain atelectatic until an adequate respiratory effort is made. The infant may make one or two feeble attempts at respiration but then cease breathing, perhaps because these efforts are of insufficient magnitude to overcome the atelectasis. In such instances the force of the respiratory movements may be increased by external stimuli while intubation and removal of secretions from the tracheo-bronchial tree may reduce the resistance to expansion so that the infant's efforts are adequate. However, certain infants appear to require additional assistance in order to overcome this resistance. If the presence of initial atelectasis is a significant factor in preventing the onset of respiration, it would seem reasonable to make a strong effort to alleviate this condition. Since the lungs offer a resistance to expansion of about 30 cm. H2O, any resuscitating device should exert pressures great enough to overcome this resistance. However, Wilson, Torrey and Johnson found that while a pressure of 24.4 cm. H2O did not cause expansion of the lung of the stillborn infant, it was great enough to cause gross pulmonary damage. Others have warned of alveolar rupture at even lower pressures and for this reason present-day resuscitators operate at low pressures. Day et al. have recently pointed out the importance of time-pressure relationships in overcoming atelectasis and demonstrated that a pressure of 40 cm. H2O effectively overcame atelectasis of animal foetal lungs without producing lung damage if the pressure was applied for less than 0.25 seconds. It was therefore of interest to develop a resuscitator operating on a "timed-pressure" principle and to study the results obtained when it was used in the resuscitation of newborn infants with markedly depressed respiration.