Is temperature important in delivery room resuscitation?

A systematic review of immune-based interventions for perinatal neuroprotection: closing the gap between animal studies and human trials

BACKGROUND

Perinatal infection/inflammation is associated with a high risk for neurological injury and neurodevelopmental impairment after birth. Despite a growing preclinical evidence base, anti-inflammatory interventions have not been established in clinical practice, partly because of the range of potential targets. We therefore systematically reviewed preclinical studies of immunomodulation to improve neurological outcomes in the perinatal brain and assessed their therapeutic potential.

METHODS

We reviewed relevant studies published from January 2012 to July 2023 using PubMed, Medline (OvidSP) and EMBASE databases. Studies were assessed for risk of bias using the SYRCLE risk of bias assessment tool (PROSPERO; registration number CRD42023395690).

RESULTS

Forty preclinical publications using 12 models of perinatal neuroinflammation were identified and divided into 59 individual studies. Twenty-seven anti-inflammatory agents in 19 categories were investigated. Forty-five (76%) of 59 studies reported neuroprotection, from all 19 categories of therapeutics. Notably, 10/10 (100%) studies investigating anti-interleukin (IL)-1 therapies reported improved outcome, whereas half of the studies using corticosteroids (5/10; 50%) reported no improvement or worse outcomes with treatment. Most studies (49/59, 83%) did not control core body temperature (a known potential confounder), and 25 of 59 studies (42%) did not report the sex of subjects. Many studies did not clearly state whether they controlled for potential study bias.

CONCLUSION

Anti-inflammatory therapies are promising candidates for treatment or even prevention of perinatal brain injury. Our analysis highlights key knowledge gaps and opportunities to improve preclinical study design that must be addressed to support clinical translation.

A Systematic Review of Magnesium Sulfate for Perinatal Neuroprotection: What Have We Learnt From the Past Decade?

There is an important unmet need to improve long term outcomes of encephalopathy for preterm and term infants. Meta-analyses of large controlled trials suggest that maternal treatment with magnesium sulfate (MgSO₄) is associated with a reduced risk of cerebral palsy and gross motor dysfunction after premature birth. However, to date, follow up to school age has found an apparent lack of long-term clinical benefit. Because of this inconsistency, it remains controversial whether MgSO₄ offers sustained neuroprotection. We systematically reviewed preclinical and clinical studies reported from January 1 2010, to January 31 2020 to evaluate the most recent advances and knowledge gaps relating to the efficacy of MgSO₄ for the treatment of perinatal brain injury. The outcomes of MgSO₄ in preterm and term-equivalent animal models of perinatal encephalopathy were highly inconsistent between studies. None of the perinatal rodent studies that suggested benefit directly controlled body or brain temperature. The majority of the studies did not control for sex, study long term histological and functional outcomes or use pragmatic treatment regimens and many did not report controlling for potential study bias. Finally, most of the recent preterm or term human studies that tested the potential of MgSO₄ for perinatal neuroprotection were relatively underpowered, but nevertheless, suggest that any improvements in neurodevelopment were at best modest or absent. On balance, these data suggest that further rigorous testing in translational preclinical models of perinatal encephalopathy is essential to ensure safety and best regimens for optimal preterm neuroprotection, and before further clinical trials of MgSO₄ for perinatal encephalopathy at term are undertaken.

Effects of 3-h hypothermia after neonatal hyperthermic hypoxic-ischemic encephalopathy in rat models on behavioral prognosis and anatomical and histological features after growth

OBJECTIVE

To clarify the effects of 3-h hypothermia on learning ability and motor function after growth, employing neonatal rat models with hyperthermic hypoxic-ischemic encephalopathy (HIE).

METHODS

We divided all rats into three groups: N (adult rats after neonatal hyperthermic HIE without subsequent 3-h hypothermia), H (adult rats after neonatal hyperthermic HIE with subsequent 3-h hypothermia) and Sham (S) groups. We evaluated their malfunctions with the rota-rod test and the step-down passive avoidance test. We also analyzed the cerebrum width and the hippocampal CA1 area of the insulted hemisphere.

RESULTS

In the rota-rod test, the result of the N group was significantly worse than that of the S group. In the step-down passive avoidance test, the result of the N group was significantly worse than those of the S and H groups. The longest cerebrum width and the hippocampal CA1 area of the insulted hemisphere of the N group were significantly smaller than those of the S and H groups.

CONCLUSION

Neonatal hyperthermic hypoxic-ischemic insult restricts motor function and learning ability after growth, and such neuronal malfunctions can be relieved by hypothermia for 3 h soon after neonatal HIE.

Progress in anesthesia and management of the newborn surgical patient

Ongoing advances in the perioperative management of the newborn have undoubtedly decreased the incidence of morbidity and mortality of this vulnerable patient group. The introduction of new surgical techniques and more comprehensive understanding of the effects of varied anesthetic drugs and techniques on the surgical newborn present many challenges for pediatric surgeons and anesthesiologists. Thorough preoperative evaluation and open communication between members of the health care team are important. A basic understanding of age-dependent variables and the interaction of anesthetic and surgical procedures is essential in minimizing perioperative morbidity and mortality.

Neonates in Ahmedabad, India, during the 2010 heat wave: a climate change adaptation study

Health effects from climate change are an international concern with urban areas at particular risk due to urban heat island effects. The burden of disease on vulnerable populations in non-climate-controlled settings has not been well studied. This study compared neonatal morbidity in a non-air-conditioned hospital during the 2010 heat wave in Ahmedabad to morbidity in the prior and subsequent years. The outcome of interest was neonatal intensive care unit (NICU) admissions for heat. During the months of April, May, and June of 2010, 24 NICU admissions were for heat versus 8 and 4 in 2009 and 2011, respectively. Both the effect of moving the maternity ward and the effect of high temperatures were statistically significant, controlling for each other. Above 42 degrees Celsius, each daily maximum temperature increase of a degree was associated with 43% increase in heat-related admissions (95% CI 9.2–88%). Lower floor location of the maternity ward within hospital which occurred after the 2010 heat wave showed a protective effect. These findings demonstrate the importance of simple surveillance measures in motivating a hospital policy change for climate change adaptation—here relocating one ward—and the potential increasing health burden of heat in non-climate-controlled institutions on vulnerable populations.

Application of plastic wrap to improve temperatures in infants born less than 30 weeks gestation: a randomized controlled trial

PURPOSE

The primary aim of the study was to evaluate whether the application of a plastic wrap immediately after birth is more effective than the standard care of temperature management for improving admission temperatures to the neonatal intensive care unit (NICU) in infants <30 weeks gestation.

DESIGN

A randomized controlled trial was conducted. Infants in the intervention group were transferred to a prewarmed radiant heater immediately after birth and encased in NeoWrap from the neck down without being dried. The infant's head was dried with a prewarmed towel and a hat added. The control group received usual care for the unit; the infant was transferred to the prewarmed radiant warmer and dried, and warm towels and a hat are then applied.

SAMPLE

A total of 92 infants were analyzed: 49 in the control group and 43 in the intervention group; 48 (52.2 percent) were <27 weeks gestation, and 44 (47.8 percent) were <30 weeks gestation. The infants' temperatures were assessed for two hours following admission.

A randomized trial of exothermic mattresses for preterm newborns in polyethylene bags

BACKGROUND AND OBJECTIVE

Hypothermia on admission to the NICU is associated with increased mortality in preterm infants. Many newborns are hypothermic on admission despite using polyethylene bags (PBs). Using exothermic mattresses (EMs) in addition to PBs may reduce hypothermia but increase hyperthermia. We wished to determine whether placing preterm newborns in PBs on EMs in the DR results in more infants with rectal temperature outside the range 36.5 to 37.5°C on NICU admission.

METHODS

Infants <31 weeks were randomly assigned before birth to treatment with or without an EM. All infants were placed in a PB and under radiant heat immediately after birth and brought to NICU in a transport incubator. Infants randomly assigned to EM were placed on a mattress immediately after delivery and remained on it until admission. Randomization was stratified by gestational age. Rectal temperature was measured with a digital thermometer on NICU admission.

RESULTS

The data safety monitoring committee recommended stopping for efficacy after analyzing data from half the planned sample. We report data for 72 infants enrolled at this time. Fewer infants in PBs on EMs had temperatures within the target range (15/37 [41%] vs 27/35 [77%], P = .002) and more had temperatures >37.5°C (17/37 [46%] vs 6/35 [17%], P = .009).

CONCLUSIONS

In very preterm newborns, using EMs in addition to PBs in the DR resulted in more infants with temperatures outside the normal range and more hyperthermia on NICU admission.

Perioperative central nervous system injury in neonates

Anaesthetic-induced developmental neurotoxicity (AIDN) has been clearly established in laboratory animal models. The possibility of neurotoxicity during uneventful anaesthetic procedures in human neonates or infants has led to serious questions about the safety of paediatric anaesthesia. However, the applicability of animal data to clinical anaesthesia practice remains uncertain. The spectre of cerebral injury due to cerebral hypoperfusion, metabolic derangements, coexisting disease, and surgery itself further muddles the picture. Given the potential magnitude of the public health importance of this issue, the clinician should be cognisant of the literature and ongoing investigations on AIDN, and raise awareness of the risks of both surgery and anaesthesia.

Warming preterm infants in the delivery room: polyethylene bags, exothermic mattresses or both?

AIMS

To compare the admission temperature of infants treated with polyethylene bags alone to infants treated with exothermic mattresses in addition to bags in the delivery room.

METHODS

We prospectively studied infants born at <31 weeks' gestation who were placed in bags at birth. Some infants were also placed on mattresses. Admission axillary temperatures were measured in all infants on admission to the neonatal intensive care. We compared the temperatures of infants treated with bags alone to those treated with mattresses and bags.

RESULTS

We studied 43 infants: 15 were treated with bags while 28 were treated with a bag and mattress. Mean admission temperature was similar between the groups. Hypothermia and hyperthermia occurred more frequently in infants treated with a bag and mattress, and more infants treated with a bag had admission temperatures 36.5-37.5°C.

CONCLUSION

The use of exothermic mattresses in addition to polyethylene bags, particularly in younger, smaller newborns, may result in more hypothermia and hyperthermia on admission. A randomised controlled trial is necessary to determine which strategy results in more infants having admission temperatures in the normal range.

Safety and efficacy of Trans-warmer mattress for preterm neonates: results of a randomized controlled trial

OBJECTIVE

To compare the admission temperatures, incidence of hypothermia and discharge outcomes of preterm neonates managed with Trans-warmer mattress (TWM) initiated in the delivery room (DR) and controls.

STUDY DESIGN

A prospective quasi-randomized controlled trial was performed between January and November 2009 on preterm neonates <32 weeks gestation. Infants in the intervention group were resuscitated and transported to neonatal intensive care unit (NICU) on a TWM, in addition to other measures recommended by the Neonatal Resuscitation Program.

RESULT

The mean (s.d.) gestational age 28.7 (3) vs 28.7 (2.4) weeks and birth weight 1151 (407) vs 1175 (413) g) were comparable in the intervention (n=53) and control (n=49) groups. Temperature of the DR, maternal temperature, 5 min Apgar score, mode of delivery, cord pH and need for resuscitation were similar in both groups. Temperature of neonates in the DR (36.3 vs 36.0 °C) was also similar. Admission temperature in the NICU was significantly higher 36.2 °C (0.8) vs 35.7 °C (0.8) and incidence of hypothermia (temperatures <36 °C) lower in the intervention group (34 vs 57%, P<0.05). TWM use was not associated with any adverse effects. On logistic regression, low birth weight, lack of use of TWM and low DR temperature were independently associated with admission hypothermia.

CONCLUSION

In this quasi-randomized controlled trial, the admission temperatures of preterm neonates on whom TWM was used were significantly higher compared to controls with a reduction in the incidence of hypothermia. A TWM initiated in the DR may be a simple efficacious method of reducing hypothermia in preterm neonates.

Polyethylene wrap for thermoregulation in the preterm infant: a randomized trial

We compared the response of temperature adaptation in preterm infants using the polyethylene wrap with and without previous drying versus the sterile preheated field. Both groups of polyethylene use achieved a mean axillary temperature of 36.5C at 30 minutes compared with 75 minutes for the group of traditional care. At 120 minutes, the incubator temperature was higher in those using preheated field, compared with infants in the polyethylene wrap with or without previous drying, (35.15C, 34.20C and 34.20C respectively; P = 0.0001). No difference in axillary or incubator temperature was found between the groups using the polyethylene wrap.

Pathophysiology of perinatal asphyxia: can we predict and improve individual outcomes?

Perinatal asphyxia occurs still with great incidence whenever delivery is prolonged, despite improvements in perinatal care. After asphyxia, infants can suffer from short- to long-term neurological sequelae, their severity depend upon the extent of the insult, the metabolic imbalance during the re-oxygenation period and the developmental state of the affected regions. Significant progresses in understanding of perinatal asphyxia pathophysiology have achieved. However, predictive diagnostics and personalised therapeutic interventions are still under initial development. Now the emphasis is on early non-invasive diagnosis approach, as well as, in identifying new therapeutic targets to improve individual outcomes. In this review we discuss (i) specific biomarkers for early prediction of perinatal asphyxia outcome; (ii) short and long term sequelae; (iii) neurocircuitries involved; (iv) molecular pathways; (v) neuroinflammation systems; (vi) endogenous brain rescue systems, including activation of sentinel proteins and neurogenesis; and (vii) therapeutic targets for preventing or mitigating the effects produced by asphyxia.

Improving neonatal unit admission temperatures in preterm babies: exothermic mattresses, polythene bags or a traditional approach?

OBJECTIVE

To investigate whether exothermic sodium acetate mattresses were associated with an improvement in the thermal care of babies <30 weeks gestation between birth and admission to a neonatal unit.

STUDY DESIGN

Analysis of a three case series of babies: the first with traditional thermal care of drying and wrapping in a towel, the second with wrapping in food standard polythene bags and the third with wrapping in polythene bags and nursing on an activated exothermic mattress. The main outcome measure was the temperature on admission to the neonatal unit.

RESULT

There were no significant differences between the groups for gestation and birth weight. Hypothermia was less frequent in the 'bag and mattress' group compared with the 'bag only' and traditional care groups (26 vs 69 vs 84%, respectively) even though the median time to admission was longest in the 'bag and mattress' group (23 min). The proportions of babies admitted with temperatures in the target range of 36.5 to 37.5 degrees C were 46, 27 and 16%, respectively. Multiple regression analysis showed that use of the mattress raised admission temperatures by 1.04 degrees C. The median temperature of babies in the 'bag and mattress' group was higher compared with the other groups (36.9 vs 36.0 vs 35.8 degrees C), but significantly more were hyperthermic (28 vs 4 and 0.4%, respectively).

CONCLUSION

Use of exothermic mattresses for babies <30 weeks gestation was associated with a significantly greater proportion of babies being admitted to the neonatal unit with a temperature in the euthermic range, but there was also an increased risk of hyperthermia.

Fetal hypoxia insults and patterns of brain injury: insights from animal models

The outcome of perinatal hypoxiaischemia is highly variable, with only a very broad relationship to the 'severity' of oxygen debt as shown by peripheral base deficit and the risk of damage. The present article examines the pathophysiology of asphyxial injury. We dissect the multiple factors that modify the risk of injury, including the depth ('severity'), duration, and repetition of the insult, the maturity, and condition of the fetus, pre-existing hypoxia, and exposure to pyrexia and infection/inflammation.

Variability in incubator humidity practices in the management of preterm infants

AIM

To determine current practice and opinion in relation to incubator humidity use in the management of preterm infants in neonatal intensive care units (NICU's) within the Australian and New Zealand Neonatal Network (ANZNN).

METHODS

A survey was conducted in 26 NICU's in the ANZNN. A senior clinical nurse in each perinatal centre participated in a telephone survey that focused on local humidification practices and on the clinicians' views and experiences of humidity use.

RESULTS

All centres routinely used supplemental humidity in the management of preterm infants. The majority of centres (77%) had written protocols to guide practice. Eighty-eight per cent commenced humidity at a high level (relative humidity > or = 80%). There was wide practice variation in the gestational age parameters determining humidification use (all gestational ages up to 37 weeks), duration of use (3-77 days), timing of initiation (admission to 72 h after birth) and weaning practices. Perceived benefits of humidification included improved thermoregulation, skin integrity, and fluid and electrolyte balance and reduced transepidermal water loss. Perceived risks included sepsis and hyperthermia.

CONCLUSIONS

Our study confirmed that incubator humidity is used routinely in the management of preterm infants in the ANZNN. Wide variation in humidification practices across NICUs reflects the paucity of research evidence. Perceived benefits and risks of humidity use were consistent with available literature. To optimise the care environment and provide an evidence base for practice further research is warranted.

Keeping infants warm: challenges of hypothermia

Hypothermia is a major cause of morbidity and mortality in infants; therefore, maintaining normal body temperatures in the delivery room is crucial. An understanding of how infants produce heat and what can be done to maintain normal body temperatures in full-term and preterm infants is essential for the preservation of thermal stability in this population. This article reviews the consequences of hypothermia, mechanisms of heat exchange and heat production in full-term and low birth-weight infants, and discusses interventions in the delivery room to alleviate hypothermia.

Admission temperatures following radiant warmer or incubator transport for preterm infants <28 weeks: a randomised study

Sixty two infants <28 weeks were occlusively wrapped and randomised to radiant warmer or incubator transport to the neonatal unit. Median axillary temperature on arrival was 36.8 degrees C in both groups. Target temperatures (36.5-37.5 degrees C) were achieved in 60% of the incubator group compared to 75% in the warmer group (not statistically significant). While powered to detect a 35% difference between warming devices, a more modest difference is not excluded.

Determinants of outcomes after head cooling for neonatal encephalopathy

OBJECTIVE

The goal of this study was to evaluate the role of factors that may determine the efficacy of treatment with delayed head cooling and mild systemic hypothermia for neonatal encephalopathy.

METHODS

A total of 218 term infants with moderate to severe neonatal encephalopathy plus abnormal amplitude-integrated electroencephalographic recordings, assigned randomly to head cooling for 72 hours, starting within 6 hours after birth (with the rectal temperature maintained at 34.5 +/- 0.5 degrees C), or conventional care, were studied. Death or severe disability at 18 months of age was assessed in a multicenter, randomized, controlled study (the CoolCap trial).

RESULTS

Treatment, lower encephalopathy grade, lower birth weight, greater amplitude-integrated electroencephalographic amplitude, absence of seizures, and higher Apgar score, but not gender or gestational age, were associated significantly with better outcomes. In a multivariate analysis, each of the individually predictive factors except for Apgar score remained predictive. There was a significant interaction between treatment and birth weight, categorized as > or =25th or <25th percentile for term, such that larger infants showed a lower frequency of favorable outcomes in the control group but greater improvement with cooling. For larger infants, the number needed to treat was 3.8. Pyrexia (> or =38 degrees C) in control infants was associated with adverse outcomes. Although there was a small correlation with birth weight, the adverse effect of greater birth weight in control infants remained significant after adjustment for pyrexia and severity of encephalopathy.

CONCLUSIONS

Outcomes after hypothermic treatment were strongly influenced by the severity of neonatal encephalopathy. The protective effect of hypothermia was greater in larger infants.

MATERNAL TEMPERATURE IN LABOUR

In this review, we are concerned primarily with pyrexia (hyperthermia; increased maternal temperature in labour) as hypothermia is rare and usually iatrogenic (as in hypothermia for cardiac bypass surgery). We start by reviewing the factors determining maternal temperature, and how it can be measured. We move on to the effects of the commonest cause of maternal pyrexia in labour in modern obstetric practice in developed countries, epidural anaesthesia. We then discuss the most feared cause of maternal pyrexia in labour, chorioamnionitis.

How has research in the last five years changed my clinical practice?

Although the practice of neonatology is increasingly evidence based, much of our assessment and treatment of newborn infants is still founded on experience, common sense, guesswork, and myth. Research may put a particular issue beyond dispute, but it often raises new questions. This review looks at the benefits of research in one area: temperature control.

Heat Loss Prevention (HeLP) in the delivery room: A randomized controlled trial of polyethylene occlusive skin wrapping in very preterm infants

OBJECTIVES

To determine if polyethylene occlusive skin wrapping of very preterm infants prevents heat loss after delivery better than conventional drying and to evaluate if any benefit is sustained after wrap removal.

STUDY DESIGN

This was a randomized controlled trial of infants <28 weeks' gestation. The experimental group was wrapped from the neck down. Only the head was dried. Control infants were dried completely. Rectal temperatures were compared on admission to the neonatal intensive care unit immediately after wrap removal and 1 hour later.

RESULTS

Of 55 infants randomly assigned (28 wrap, 27 control), 2 died in the delivery room and 53 completed the study. Wrapped infants had a higher mean rectal admission temperature, 36.5 degrees C (SD, 0.8 degrees C), compared with 35.6 degrees C (SD, 1.3 degrees C) in control infants ( P = .002). One hour later, mean rectal temperatures were similar in both groups (36.6 degrees C, SD, 0.7 degrees C vs 36.4 degrees C, SD, 0.9 degrees C, P = .4). Size at birth was an important determinant of heat loss: Mean rectal admission temperature increased by 0.21 degrees C (95% CI, 0.04 to 0.4) with each 100-g increase in birth weight.

CONCLUSIONS

Polyethylene occlusive skin wrapping prevents rather than delays heat loss at delivery in very preterm infants.

Effect of mild hypothermia and hypoxia on blood flow and oxygen consumption of the fetal sheep brain

This study was undertaken to measure the effects of mild hypothermia on cerebral blood flow and metabolism and cardiovascular responses to hypoxia in the fetal sheep. Near-term fetal sheep were chronically instrumented with laser Doppler flowmetry in the parietal cortex for measurement of relative changes in cerebral blood flow, as well as with arterial and sagittal sinus catheters for measurement of oxygen extraction by the brain and a cooling coil around the fetal thorax. Fetuses were studied during cooling alone, cooling with superimposed maternal hypoxia to achieve a fetal arterial Po2 of 1.33 to 1.60 kPa, or hypoxia alone. In response to cooling alone [1.6 degrees +/- 0.1 degrees C (mean +/- SEM) decrease in brain temperature], fetal blood pressure and heart rate both increased significantly whereas cerebral blood flow decreased 14 +/- 4%, commensurate with a 24 +/- 8% decline in cerebral metabolic rate. Administration of moderate hypoxia during cooling resulted in a significant increase in cerebral blood flow, decreased heart rate, and no further increase in blood pressure. In response to hypoxia alone, fetal blood pressure was significantly increased, heart rate was decreased, and cerebral blood flow increased by 24 +/- 8%, whereas cerebral metabolic rate decreased by 38 +/- 13%. Arteriovenous oxygen extraction was unchanged by cooling alone but increased significantly in response to hypoxia administered during cooling. We therefore conclude that oxygen delivery to the fetal sheep brain remains coupled to metabolic rate during hypothermia and that hypothermia does not impair the compensatory cardiovascular responses of the fetus to acute moderate hypoxia.

Effects of hyperthermia on hypoxic-ischemic brain damage in the immature rat: its influence on caspase-3-like protease

OBJECTIVE

Recent clinical studies suggested that intrapartum maternal fever is a strong independent risk factor for neonatal encephalopathy. With use of a well-studied rat model of neonatal hypoxic-ischemic encepalopathy, this study investigated the hypothesis that intraischemic hyperthermia accelerates and worsens brain injury in immature animals and examined whether apoptotic cell death machinery is involved in the underlying mechanisms.

STUDY DESIGN

Seven-day-old rats underwent a combination of left common carotid artery ligation and exposure to 8% oxygen for 15 minutes (n = 32 rats). During the 15-minute hypoxic insult, body temperature was elevated to 40 degrees C in 16 animals (hyperthermic hypoxic insult group), and was maintained at 37 degrees C in 16 animals (normothermic hypoxic insult group). Then both groups were placed in the same chamber in a water bath at 37 degrees C for 24 hours and finally returned to the mothers. Caspase-3-like activity was assessed 36 hours after the hypoxic-ischemic insult. One week later, microtubule-associated protein-2 immunostaining was used to examine neuronal damage.

RESULTS

Intraischemic hyperthermia was shown to activate the caspase-3 activity 36 hours after hypoxia-ischemia while caspase-3 was activated insignificantly in the normothermic hypoxic insult group at that time. The hyperthermic hypoxic insult group also showed a reduced microtubule-associated protein-2-positive area 7 days after hypoxia-ischemia compared with that in the normothermia group.

CONCLUSION

Hyperthermia during hypoxia-ischemia makes the immature brain inordinately susceptible to hypoxic-ischemic insult and causes brain injury, even if hypoxic-ischemic insult is so mild that it causes no or little injury by itself. This effect may be mediated by the escalation of the apoptotic cell death pathway in the immature animal.

The postnatal management of the asphyxiated term infant

Investigations in animal models of hypoxic-ischemic injury have not translated into clinical trials of success because of the complex pathology of hypoxic-ischemic brain injury in neonates, the difficulty in defining the onset and duration and severity of the injury, the underlying predisposing disorders of the mothers or the infant, the side effects of many of the investigational drugs precluded clinical use, and many of the investigational agents interfered with only one step of the cascade of events that lead to brain injury. It is possible that a combination of therapeutic agents, including those that affect different levels of the cascade to cell death, will have the greatest neuroprotective effects. Modest hypothermia postpones secondary energy failure and can prolong the window while pharmacotherapeutic agents can be used. It is possible that in the future, sequential administration of agents or strategies that are initiated in the intrapartum period and continued postnatally will be the optimum method for treating infants who are at highest risk for brain injury following acute hypoxic-ischemic asphyxia.

A prospective clinical audit of neonatal resuscitation practices in Canada

PURPOSE

This is a prospective audit to determine the frequency of resuscitation interventions in the clinical setting and to compare self-reports of clinical performance with the existing Neonatal Resuscitation Program (NRP) and Canadian National Guidelines for Neonatal Resuscitation.

SUBJECTS

Fifty-six level I, II, and III hospitals in Canada participated. Any infant requiring resuscitation, as defined by the need for at least positive pressure ventilation (PPV), was eligible for inclusion (n = 783 resuscitations).

DESIGN AND METHODS

A prospective self-report audit was chosen and data were collected over a 6-month period in 1998. The audit focused on the use of PPV, intubation, chest compressions, free-flow oxygen, or medications during the resuscitation. The infant's temperature at the end of resuscitation was also noted. The data were analyzed with descriptive statistics. The composition of the resuscitation team and their NRP certification status were recorded.

PRINCIPAL RESULTS

The need for resuscitation was not anticipated in 76% of the cases (596 of 783). Errors in the sequencing of care, such as delays in initiating PPV, provision of chest compressions before or without establishing an airway and ventilatory support, and administering naloxone before PPV, were reported. Resuscitations attended by a team of NRP certified providers had improved sequencing when compared with those in which only some individual providers were certified. Chest compressions were provided in 8% of the cases (65 of 783). Medications were used in 14% (113/783) of all cases. Providers in level I hospitals performed chest compressions more frequently than those in level II and III settings. At the end of the resuscitation, 27% of the infants were hypothermic (142 of 520), and 25% were hyperthermic (128 of 520). Overall, 52% were out of the normal neutral range.

CONCLUSIONS

Clear differences between the NRP guidelines and actual clinical practice were shown. A high rate of unanticipated resuscitations, delivery room medications, and chest compressions was described. Postresuscitation hypothermia or hyperthermia were common. Improved sequencing was noted when the entire resuscitation team was NRP certified. Certification in NRP does not assure competency, nor does it ensure compliance with established standards of care.