Relationship between arterial partial oxygen pressure after resuscitation from cardiac arrest and mortality in children

Epinephrine Dosing Intervals Are Associated With Pediatric In-Hospital Cardiac Arrest Outcomes: A Multicenter Study

OBJECTIVES

Data to support epinephrine dosing intervals during cardiopulmonary resuscitation (CPR) are conflicting. The objective of this study was to evaluate the association between epinephrine dosing intervals and outcomes. We hypothesized that dosing intervals less than 3 minutes would be associated with improved neurologic survival compared with greater than or equal to 3 minutes.

DESIGN

This study is a secondary analysis of The ICU-RESUScitation Project (NCT028374497), a multicenter trial of a quality improvement bundle of physiology-directed CPR training and post-cardiac arrest debriefing.

SETTING

Eighteen PICUs and pediatric cardiac ICUs in the United States.

PATIENTS

Subjects were 18 years young or younger and 37 weeks old or older corrected gestational age who had an index cardiac arrest. Patients who received less than two doses of epinephrine, received extracorporeal CPR, or had dosing intervals greater than 8 minutes were excluded.

INTERVENTIONS

The primary exposure was an epinephrine dosing interval of less than 3 vs. greater than or equal to 3 minutes.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was survival to discharge with a favorable neurologic outcome defined as a Pediatric Cerebral Performance Category score of 1-2 or no change from baseline. Regression models evaluated the association between dosing intervals and: 1) survival outcomes and 2) CPR duration. Among 382 patients meeting inclusion and exclusion criteria, median age was 0.9 years (interquartile range 0.3-7.6 yr) and 45% were female. After adjustment for confounders, dosing intervals less than 3 minutes were not associated with survival with favorable neurologic outcome (adjusted relative risk [aRR], 1.10; 95% CI, 0.84-1.46; p = 0.48) but were associated with improved sustained return of spontaneous circulation (ROSC) (aRR, 1.21; 95% CI, 1.07-1.37; p < 0.01) and shorter CPR duration (adjusted effect estimate, -9.5 min; 95% CI, -14.4 to -4.84 min; p < 0.01).

CONCLUSIONS

In patients receiving at least two doses of epinephrine, dosing intervals less than 3 minutes were not associated with neurologic outcome but were associated with sustained ROSC and shorter CPR duration.

Hyperoxemia among Pediatric Intensive Care Unit Patients Receiving Oxygen Therapy

Supratherapeutic oxygen levels consistently cause oxygen toxicity in the lungs and other organs. The prevalence and severity of hyperoxemia among pediatric intensive care unit (PICU) patients remain unknown. This was the first study to examine the prevalence and duration of hyperoxemia in PICU patients receiving oxygen therapy. This is a retrospective chart review. This was performed in a setting of 36-bed PICU in a quaternary-care children's hospital. All the patients were children aged <18 years, admitted to the PICU for ≥24 hours, receiving oxygen therapy for ≥12 hours who had at least one arterial blood gas during this time. There was no intervention. Of 5,251 patients admitted to the PICU, 614 were included in the study. On average, these patients received oxygen therapy for 91% of their time in the PICU and remained hyperoxemic, as measured by pulse oximetry, for 65% of their time on oxygen therapy. Patients on oxygen therapy remained hyperoxemic for a median of 38 hours per patient and only 1.1% of patients did not experience any hyperoxemia. Most of the time (87.5%) patients received oxygen therapy through a fraction of inspired oxygen (FiO 2 )-adjustable device. Mean FiO 2 on noninvasive support was 0.56 and on invasive support was 0.37. Mean partial pressure of oxygen (PaO 2 ) on oxygen therapy was 108.7 torr and 3,037 (42.1%) of PaO 2 measurements were >100 torr. Despite relatively low FiO 2 , PICU patients receiving oxygen therapy are commonly exposed to prolonged hyperoxemia, which may contribute to ongoing organ injury.

Association of Pediatric Postcardiac Arrest Ventilation and Oxygenation with Survival Outcomes

Rationale: Adult and pediatric studies provide conflicting data regarding whether post-cardiac arrest hypoxemia, hyperoxemia, hypercapnia, and/or hypocapnia are associated with worse outcomes. Objectives: We sought to determine whether postarrest hypoxemia or postarrest hyperoxemia is associated with lower rates of survival to hospital discharge, compared with postarrest normoxemia, and whether postarrest hypocapnia or hypercapnia is associated with lower rates of survival, compared with postarrest normocapnia. Methods: An embedded prospective observational study during a multicenter interventional cardiopulmonary resuscitation trial was conducted from 2016 to 2021. Patients ⩽18 years old and with a corrected gestational age of ≥37 weeks who received chest compressions for cardiac arrest in one of the 18 intensive care units were included. Exposures during the first 24 hours postarrest were hypoxemia, hyperoxemia, or normoxemia-defined as lowest arterial oxygen tension/pressure (PaO2) <60 mm Hg, highest PaO2 ⩾200 mm Hg, or every PaO2 60-199 mm Hg, respectively-and hypocapnia, hypercapnia, or normocapnia, defined as lowest arterial carbon dioxide tension/pressure (PaCO2) <30 mm Hg, highest PaCO2 ⩾50 mm Hg, or every PaCO2 30-49 mm Hg, respectively. Associations of oxygenation and carbon dioxide group with survival to hospital discharge were assessed using Poisson regression with robust error estimates. Results: The hypoxemia group was less likely to survive to hospital discharge, compared with the normoxemia group (adjusted relative risk [aRR] = 0.71; 95% confidence interval [CI] =  0.58-0.87), whereas survival in the hyperoxemia group did not differ from that in the normoxemia group (aRR = 1.0; 95% CI = 0.87-1.15). The hypercapnia group was less likely to survive to hospital discharge, compared with the normocapnia group (aRR = 0.74; 95% CI = 0.64-0.84), whereas survival in the hypocapnia group did not differ from that in the normocapnia group (aRR = 0.91; 95% CI = 0.74-1.12). Conclusions: Postarrest hypoxemia and hypercapnia were each associated with lower rates of survival to hospital discharge.

Approaches to neuroprotection in pediatric neurocritical care

Acute neurologic injuries represent a common cause of morbidity and mortality in children presenting to the pediatric intensive care unit. After primary neurologic insults, there may be cerebral brain tissue that remains at risk of secondary insults, which can lead to worsening neurologic injury and unfavorable outcomes. A fundamental goal of pediatric neurocritical care is to mitigate the impact of secondary neurologic injury and improve neurologic outcomes for critically ill children. This review describes the physiologic framework by which strategies in pediatric neurocritical care are designed to reduce the impact of secondary brain injury and improve functional outcomes. Here, we present current and emerging strategies for optimizing neuroprotective strategies in critically ill children.

Admission Pao2 and Mortality Among PICU Patients and Select Diagnostic Subgroups

OBJECTIVES

Evaluate the relationship between admission Pao2 and mortality in a large multicenter dataset and among diagnostic subgroups.

DESIGN

Retrospective cohort study.

SETTING

North American PICUs participating in Virtual Pediatric Systems, LLC (VPS), 2015-2019.

PATIENTS

Noncardiac patients 18 years or younger admitted to a VPS PICU with admission Pao2.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thirteen thousand seventy-one patient encounters were included with an overall mortality of 13.52%. Age categories were equally distributed among survivors and nonsurvivors with the exception of small differences among neonates and adolescents. Importantly, there was a tightly fitting quadratic relationship between admission Pao2 and mortality, with the highest mortality rates seen among hypoxemic and hyperoxemic patients (likelihood-ratio test p < 0.001). This relationship persisted after adjustment for illness severity using modified Pediatric Index of Mortality 3 scores. A similar U-shaped relationship was demonstrated among patients with diagnoses of trauma, head trauma, sepsis, renal failure, hemorrhagic shock, and drowning. However, among the 1,500 patients admitted following cardiac arrest, there was no clear relationship between admission Pao2 and mortality.

CONCLUSIONS

In a large multicenter pediatric cohort, admission Pao2 demonstrates a tightly fitting quadratic relationship with mortality. The persistence of this relationship among some but not all diagnostic subgroups suggests the pathophysiology of certain disease states may modify the hyperoxemia association.

Temporal Patterns in Brain Tissue and Systemic Oxygenation Associated with Mortality After Severe Traumatic Brain Injury in Children

BACKGROUND

Brain tissue hypoxia is an independent risk factor for unfavorable outcomes in traumatic brain injury (TBI); however, systemic hyperoxemia encountered in the prevention and/or response to brain tissue hypoxia may also impact risk of mortality. We aimed to identify temporal patterns of partial pressure of oxygen in brain tissue (PbtO2), partial pressure of arterial oxygen (PaO2), and PbtO2/PaO2 ratio associated with mortality in children with severe TBI.

METHODS

Data were extracted from the electronic medical record of a quaternary care children's hospital with a level I trauma center for patients ≤ 18 years old with severe TBI and the presence of PbtO2 and/or intracranial pressure monitors. Temporal analyses were performed for the first 5 days of hospitalization by using locally estimated scatterplot smoothing for less than 1,000 observations and generalized additive models with integrated smoothness estimation for more than 1,000 observations.

RESULTS

A total of 138 intracranial pressure-monitored patients with TBI (median 5.0 [1.9-12.8] years; 65% boys; admission Glasgow Coma Scale score 4 [3-7]; mortality 18%), 71 with PbtO2 monitors and 67 without PbtO2 monitors were included. Distinct patterns in PbtO2, PaO2, and PbtO2/PaO2 were evident between survivors and nonsurvivors over the first 5 days of hospitalization. Time-series analyses showed lower PbtO2 values on day 1 and days 3-5 and lower PbtO2/PaO2 ratios on days 1, 2, and 5 among patients who died. Analysis of receiver operating characteristics curves using Youden's index identified a PbtO2 of 30 mm Hg and a PbtO2/PaO2 ratio of 0.12 as the cut points for discriminating between survivors and nonsurvivors. Univariate logistic regression identified PbtO2 < 30 mm Hg, hyperoxemia (PaO2 ≥ 300 mm Hg), and PbtO2/PaO2 ratio < 0.12 to be independently associated with mortality.

CONCLUSIONS

Lower PbtO2, higher PaO2, and lower PbtO2/PaO2 ratio, consistent with impaired oxygen diffusion into brain tissue, were associated with mortality in this cohort of children with severe TBI. These results corroborate our prior work that suggests targeting a higher PbtO2 threshold than recommended in current guidelines and highlight the potential use of the PbtO2/PaO2 ratio in the management of severe pediatric TBI.

Association of Arterial Hyperoxia With Outcomes in Critically Ill Children: A Systematic Review and Meta-analysis

IMPORTANCE

Oxygen supplementation is a cornerstone treatment in pediatric critical care. Accumulating evidence suggests that overzealous use of oxygen, leading to hyperoxia, is associated with worse outcomes compared with patients with normoxia.

OBJECTIVES

To evaluate the association of arterial hyperoxia with clinical outcome in critically ill children among studies using varied definitions of hyperoxia.

DATA SOURCES

A systematic search of EMBASE, MEDLINE, Cochrane Library, and ClinicalTrials.gov from inception to February 1, 2021, was conducted.

STUDY SELECTION

Clinical trials or observational studies of children admitted to the pediatric intensive care unit that examined hyperoxia, by any definition, and described at least 1 outcome of interest. No language restrictions were applied.

DATA EXTRACTION AND SYNTHESIS

The Meta-analysis of Observational Studies in Epidemiology guideline and Newcastle-Ottawa Scale for study quality assessment were used. The review process was performed independently by 2 reviewers. Data were pooled with a random-effects model.

MAIN OUTCOMES AND MEASURES

The primary outcome was 28-day mortality; this time was converted to mortality at the longest follow-up owing to insufficient studies reporting the initial primary outcome. Secondary outcomes included length of stay, ventilator-related outcomes, extracorporeal organ support, and functional performance.

RESULTS

In this systematic review, 16 studies (27 555 patients) were included. All, except 1 randomized clinical pilot trial, were observational cohort studies. Study populations included were post-cardiac arrest (n = 6), traumatic brain injury (n = 1), extracorporeal membrane oxygenation (n = 2), and general critical care (n = 7). Definitions and assessment of hyperoxia differed among included studies. Partial pressure of arterial oxygen was most frequently used to define hyperoxia and mainly by categorical cutoff. In total, 11 studies (23 204 patients) were pooled for meta-analysis. Hyperoxia, by any definition, showed an odds ratio of 1.59 (95% CI, 1.00-2.51; after Hartung-Knapp adjustment, 95% CI, 1.05-2.38) for mortality with substantial between-study heterogeneity (I2 = 92%). This association was also found in less heterogeneous subsets. A signal of harm was observed at higher thresholds of arterial oxygen levels when grouped by definition of hyperoxia. Secondary outcomes were inadequate for meta-analysis.

CONCLUSIONS AND RELEVANCE

These results suggest that, despite methodologic limitations of the studies, hyperoxia is associated with mortality in critically ill children. This finding identifies the further need for prospective observational studies and importance to address the clinical implications of hyperoxia in critically ill children.

Hyperoxia after pediatric cardiac arrest: Association with survival and neurological outcomes

OBJECTIVE

To evaluate the association between hyperoxia in the first 24 hours after in-hospital pediatric cardiac arrest and mortality and poor neurological outcome.

METHODS

This is a retrospective cohort study of inpatients in a freestanding children's hospital. We included all patients younger than 18 years of age with in-hospital cardiac arrest between December 2012 and December 2019, who achieved return of circulation (ROC) for longer than 20 minutes, survived at least 24 hours after cardiac arrest, and had documented PaO2 or SpO2 during the first 24 hours after ROC. Hyperoxia was defined as having at least one level of PaO2 above 200 mmHg in the first 24 hours after cardiac arrest.

RESULTS

There were 187 patients who met eligibility criteria, of whom 48% had hyperoxia during the first 24 hours after cardiac arrest. In-hospital mortality was 41%, with similar mortality between oxygenation groups (hyperoxia 45% vs no hyperoxia 38%). We did not observe an association between hyperoxia and in-hospital mortality or poor neurological outcome after adjusting for confounders (odds ratio 1.2, 95% confidence interval 0.5-2.8). On sensitivity analysis using two additional cutoffs of PaO2 (>150 mmHg and > 300 mmHg), there was also no association with in-hospital mortality or poor neurological outcome after adjusting for confounders. Similarly, on multivariable logistic regression using SpO2 > 99% as the exposure, there was no difference in the frequency of death or poor neurological outcome at hospital discharge.

CONCLUSION

Hyperoxia after pediatric cardiac arrest was common and was not associated with worse in-hospital outcomes.

The outcomes of using high oxygen concentration in pediatric patients

Oxygen reserve index, available as part of Masimo Rainbow SET pulse oximetry, is a noninvasive and continuous variable intended to provide insight into a patient's oxygen status in the moderate hyperoxic range (PaO₂ > 100 and ≤ 200 mm Hg), defined as a patient's oxygen "reserve". When used in conjunction with pulse oximetry, ORi extends the knowledge on a patient's oxygen status providing clinically important information helping to prevent hyperoxemia and hypoxemia. There are limited data on patients undergoing craniosynostosis surgery. Our primary goal was to evaluate the effects of different concentrations of inspiratory oxygen (FiO₂) on patient oxygenation status by monitoring ORi. Thirty patients scheduled for craniosynostosis were included in this observational cohort study. Patients were randomized into two equal groups: Group 1 received a fraction of inspired oxygen of 0.8 and group 2 received a FiO₂ of 0.6 during induction of anaesthesia. In addition to standard haemodynamic variables with ORi were recorded at baseline 1 min, 5 min, 60 min, and 120 min after intubation. Postoperative complications, length of stay in the intensive care unit and hospital were recorded. In total, 14 patients were evaluated in each group. Gender, age, BMI, ASA scores were similar between groups (p > 0.05). In Group 1, ORi values were significantly higher when compared to group 2 at baseline (0.86 ± 0.21 vs 0.45 ± 0.32, p = 0.001), one minute (0.61 ± 0.24 vs 0.27 ± 0.21, p = 0.001), and 5 min (0.34 ± 0.31 vs 0.10 ± 0.13, p = 0.033). High inspired oxygen concentration during induction of anesthesia in pediatric patients is associated with higher levels of ORi. Therefore, ORi may provide the means to safely reduce the inspired oxygen fraction during inhalational induction in paediatric patients.

Post-cardiac arrest physiology and management in the neonatal intensive care unit

AIM

The importance of high-quality post-cardiac arrest care is well-described in adult and paediatric populations, but data are lacking to inform post-cardiac arrest care in the neonatal intensive care unit (NICU). The objective of this study was to describe post-cardiac arrest physiology and management in a quaternary NICU.

METHODS

Retrospective descriptive study of post-cardiac arrest physiology and management. Data were abstracted from electronic medical records and an institutional resuscitation database. A cardiac arrest was defined as ≥1 minute of chest compressions. Only index arrests were analysed. Descriptive statistics were used to report patient, intra-arrest, and post-arrest characteristics.

RESULTS

There were 110 index cardiac arrests during the 5-year study period from 1/2017-2/2021. The majority (69%) were acute respiratory compromise leading to cardiopulmonary arrest (ARC-CPA) and 26% were primary cardiopulmonary arrests (CPA). Vital sign monitoring within 24 hours post-arrest was variable, especially non-invasive blood pressure frequency (median 5, range 1-44 measurements). There was a high prevalence of hypothermia (73% of arrest survivors). There was substantial variability in laboratory frequency within 24 hours post-arrest. Patients with primary CPA received significantly more lab testing and had a higher prevalence of acidosis (pH < 7.2) than those with ARC-CPA.

CONCLUSIONS

We identified significant variation in post-arrest management and a high prevalence of hypothermia. These data highlight the need for post-arrest management guidelines specific to neonatal physiology, as well as opportunities for quality improvement initiatives. Further research is needed to ascertain the impact of neonatal post-arrest management on long-term outcomes and survival.

ORi™: a new indicator of oxygenation

In the perioperative period, hypoxemia and hyperoxia are crucial factors that require attention, because they greatly affect patient prognoses. The pulse oximeter has been the only noninvasive monitor that can be used as a reference of oxygenation in current anesthetic management; however, in recent years, a new monitoring method that uses the oxygen reserve index (ORi™) has been developed by Masimo Corp. ORi is an index that reflects the state of moderate hyperoxia (partial pressure of arterial oxygen [PaO2] between 100 and 200 mmHg) using a non-unit scale between 0.00 and 1.00. ORi monitoring performed together with percutaneous oxygen saturation (SpO2) measurements may become an important technique in the field of anesthetic management, for measuring oxygenation reserve capacity. By measuring ORi, it is possible to predict hypoxemia and to detect hyperoxia at an early stage. In this review, we summarize the method of ORi, cautions for its use, and suitable cases for its use. In the near future, the monitoring of oxygen concentrations using ORi may become increasingly common for the management of respiratory function before, after, and during surgery.

Impact of Arterial Carbon Dioxide and Oxygen Content on Cerebral Autoregulation Monitoring Among Children Supported by ECMO

BACKGROUND

Cerebral autoregulation (CA) impairment is associated with neurological complications among children supported by extracorporeal membrane oxygenation (ECMO). Severe variations of arterial CO₂ (PaCO₂) and O₂ (PaO₂) tension after ECMO onset are common and associate with mortality and poor neurological outcome. The impact of gas exchange on CA among critically ill patients is poorly studied.

METHODS

Retrospective analysis of data collected prospectively from 30 children treated with veno-arterial or veno-venous ECMO in the PICU of Nantes University Hospital, France. A correlation coefficient between the variations of regional cerebral oxygen saturation (rSO₂) and the variations of mean arterial blood pressure (MAP) was calculated as an index of CA (cerebral oxygenation reactivity index, COx). Cox-MAP plots were investigated allowing determining lower limit of autoregulation (LLA) and upper limit of autoregulation (ULA) limits of autoregulation. Age-based normal blood pressure was used to adjust the MAP, LLA, and ULA data from each patient and then reported as percentage (nMAP, nLLA, and nULA, respectively). RSO₂, COx, nMAP, nLLA, and nULA values were averaged over one hour before each arterial blood gas (ABG) sample during ECMO run.

RESULTS

Thirty children (median age 4.8 months [Interquartile range (IQR) 0.7-39.1], median weight 5 kg [IQR 4-15]) experiencing 31 ECMO runs were included in the study. Three hundred and ninety ABGs were analyzed. The highest values of COx were observed on day 1 (D1) of ECMO. The relationship between COx and PaCO₂ was nonlinear, but COx values tended to be lower in case of hypercapnia compared to normocapnia. During the whole ECMO run, a weak but significant correlation between PaCO₂ and nULA was observed (R = 0.432, p = 0.02). On D1 of ECMO, this correlation was stronger (R = 0.85, p = 0.03) and a positive correlation between nLLA and PaCO₂ was also found (R = 0.726, p < 0.001). A very weak negative correlation between PaO₂ and nULA was observed within the whole ECMO run and on D1 of ECMO (R =  -0.07 p = 0.04 and R =  -0.135 p =  <0.001, respectively). The difference between nULA and nLLA representing the span of the autoregulation plateau was positively correlated with PaCO₂ and negatively correlated with PaO₂ (R = 0.224, p = 0.01 and R =  -0.051, p = 0.004, respectively).

CONCLUSIONS

We observed a complex relationship between PaCO₂ and CA, influenced by the level of blood pressure. Hypercapnia seems to be globally protective in normotensive or hypertensive condition, while, in case of very low MAP, hypercapnia may disturb CA as it increases LLA. These data add additional arguments for very cautiously lower PaCO₂, especially after ECMO start.

Randomized trial of oxygen weaning strategies following chest compressions during neonatal resuscitation

BACKGROUND

The Neonatal Resuscitation Program (NRP) recommends using 100% O2 during chest compressions and adjusting FiO2 based on SpO2 after return of spontaneous circulation (ROSC). The optimal strategy for adjusting FiO2 is not known.

METHODS

Twenty-five near-term lambs asphyxiated by umbilical cord occlusion to cardiac arrest were resuscitated per NRP. Following ROSC, lambs were randomized to gradual decrease versus abrupt wean to 21% O2 followed by FiO2 titration to achieve NRP SpO2 targets. Carotid blood flow and blood gases were monitored.

RESULTS

Three minutes after ROSC, PaO2 was 229 ± 32 mmHg in gradual wean group compared to 57 ± 13 following abrupt wean to 21% O2 (p < 0.001). PaO2 remained high in the gradual wean group at 10 min after ROSC (110 ± 10 vs. 67 ± 12, p < 0.01) despite similar FiO2 (~0.3) in both groups. Cerebral O2 delivery (C-DO2) was higher above physiological range following ROSC with gradual wean (p < 0.05). Lower blood oxidized/reduced glutathione ratio (suggesting less oxidative stress) was observed with abrupt wean.

CONCLUSION

Weaning FiO2 abruptly to 0.21 with adjustment based on SpO2 prevents surge in PaO2 and C-DO2 and minimizes oxidative stress compared to gradual weaning from 100% O2 following ROSC. Clinical trials with neurodevelopmental outcomes comparing post-ROSC FiO2 weaning strategies are warranted.

IMPACT

In a lamb model of perinatal asphyxial cardiac arrest, abrupt weaning of inspired oxygen to 21% prevents excessive oxygen delivery to the brain and oxidative stress compared to gradual weaning from 100% oxygen following return of spontaneous circulation. Clinical studies assessing neurodevelopmental outcomes comparing abrupt and gradual weaning of inspired oxygen after recovery from neonatal asphyxial arrest are warranted.

Racial, ethnic, and socioeconomic disparities in paediatric critical care in the USA

In an era of tremendous medical advancements, it is important to characterise and address inequities in the provision of health care and in outcomes. There is a large body of evidence describing such disparities by race or ethnicity and socioeconomic position in critically ill adults; however, this important issue has received less attention in children and adolescents (aged ≤21 years). This Review presents a summary of the available evidence on disparities in outcomes in paediatric critical illness in the USA as a result of racism and socioeconomic privilege. The majority of evidence of racial and socioeconomic disparities in paediatric critical care originates from the USA and is retrospective, with only one prospective intervention-based study. Although there is mixed evidence of disparities by race or ethnicity and socioeconomic position in general paediatric intensive care unit admissions and outcomes in the USA, there are striking trends within some disease processes. Notably, there is evidence of disparities in management and outcomes for out-of-hospital cardiac arrest, asthma, severe trauma, sepsis, and oncology, and in families' perceptions of care. Furthermore, there is clear evidence that critical care research is limited by under-enrolment of participants from minority race or ethnicity groups. We advocate for rigorous research standards and increases in the recruitment and enrolment of a diverse range of participants in paediatric critical care research to better understand the disparities observed, including the effects of racism and poverty. A clearer understanding of when, where, and how such disparities affect patients will better enable the development of effective strategies to inform practice, interventions, and policy.

Hyperoxemia Is Associated With Mortality in Critically Ill Children

Multiple studies among adults have suggested a non-linear relationship between arterial partial pressure of oxygen (PaO₂) and clinical outcomes. Meta-analyses in this population suggest that high levels of supplemental oxygen resulting in hyperoxia are associated with mortality. This mini-review focuses on the non-neonatal pediatric literature examining the relationship between PaO₂ and mortality. While only one pilot pediatric randomized-controlled trials exists, over the past decade, there have been at least eleven observational studies examining the relationship between PaO₂ values and mortality in critically ill children. These analyses of mixed-case pediatric ICU populations have generally reported a parabolic (“u-shaped”) relationship between PaO₂ and mortality, similar to that seen in the adult literature. However, the estimates of the point at which hyperoxemia becomes deleterious have varied widely (300–550 mmHg). Where attempted, this effect has been robust to analyses restricted to the first PaO₂ value obtained, those obtained within 24 h of admission, anytime during admission, and the number of hyperoxemic blood gases over time. These findings have also been noted when using various methods of risk-adjustment (accounting for severity of illness scores or complex chronic conditions). Similar relationships were found in the majority of studies restricted to patients undergoing care after cardiac arrest. Taken together, the majority of the literature suggests that there is a robust parabolic relationship between PaO₂ and risk-adjusted pediatric ICU mortality, but that the exact threshold at which hyperoxemia becomes deleterious is unclear, and likely beyond the typical target value for most clinical indications. Findings suggest that clinicians should remain judicious and thoughtful in the use of supplemental oxygen therapy in critically ill children.

Hyperoxia During Cardiopulmonary Bypass Is Associated With Mortality in Infants Undergoing Cardiac Surgery

OBJECTIVES

Patients undergoing cardiac surgery using cardiopulmonary bypass have variable degrees of blood oxygen tension during surgery. Hyperoxia has been associated with adverse outcomes in critical illness. Data are not available regarding the association of hyperoxia and outcomes in infants undergoing cardiopulmonary bypass. We hypothesize that among infants undergoing cardiac surgery, hyperoxia during cardiopulmonary bypass is associated with greater odds of morbidity and mortality.

DESIGN

Retrospective study.

SETTING

Single center at an academic tertiary children's hospital.

PATIENTS

All infants (< 1 yr) undergoing cardiopulmonary bypass between January 1, 2015, and December 31, 2017, excluding two patients who were initiated on extracorporeal membrane oxygenation in the operating room.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The study included 469 infants with a median age of 97 days (interquartile range, 14-179 d), weight 4.9 kg (interquartile range, 3.4-6.4 kg), and cardiopulmonary bypass time 128 minutes (interquartile range, 91-185 min). A Pao2 of 313 mm Hg (hyperoxia) on cardiopulmonary bypass had highest sensitivity with specificity greater than 50% for association with operative mortality. Approximately, half of the population (237/469) had hyperoxia on cardiopulmonary bypass. Infants with hyperoxia were more likely to have acute kidney injury, prolonged postoperative length of stay, and mortality. They were younger, weighed less, had longer cardiopulmonary bypass times, and had higher Society of Thoracic Surgeons and the European Association for Cardio-Thoracic Surgery mortality scores. There was no difference in sex, race, preoperative creatinine, single ventricle physiology, or presence of genetic syndrome. On multivariable analysis, hyperoxia was associated with greater odds of mortality (odds ratio, 4.3; 95% CI, 1.4-13.2) but failed to identify an association with acute kidney injury or prolonged postoperative length of stay. Hyperoxia was associated with greater odds of mortality in subgroup analysis of neonatal patients.

CONCLUSIONS

Hyperoxia occurred in a substantial portion of infants undergoing cardiopulmonary bypass for cardiac surgery. Hyperoxia during cardiopulmonary bypass was an independent risk factor for mortality and may be a modifiable risk factor. Furthermore, hyperoxia during cardiopulmonary bypass was associated with four-fold greater odds of mortality within 30 days of surgery. Hyperoxia failed to identify an association with development of acute kidney injury or prolonged postoperative length of stay when controlling for covariables. Validation of our data among other populations is necessary to better understand and elucidate potential mechanisms underlying the association between excess oxygen delivery during cardiopulmonary bypass and outcome.

Pediatric In-Hospital Cardiac Arrest and Cardiopulmonary Resuscitation in the United States: A Review

IMPORTANCE

Pediatric in-hospital cardiac arrest (IHCA) occurs frequently and is associated with high morbidity and mortality. The objective of this narrative review is to summarize the current knowledge and recommendations regarding pediatric IHCA and cardiopulmonary resuscitation (CPR).

OBSERVATIONS

Each year, more than 15 000 children receive CPR for cardiac arrest during hospitalization in the United States. As many as 80% to 90% survive the event, but most patients do not survive to hospital discharge. Most IHCAs occur in intensive care units and other monitored settings and are associated with respiratory failure or shock. Bradycardia with poor perfusion is the initial rhythm in half of CPR events, and only about 10% of events have an initial shockable rhythm. Pre-cardiac arrest systems focus on identifying at-risk patients and ensuring that they are in monitored settings. Important components of CPR include high-quality chest compressions, timely defibrillation when indicated, appropriate ventilation and airway management, administration of epinephrine to increase coronary perfusion pressure, and treatment of the underlying cause of cardiac arrest. Extracorporeal CPR and measurement of physiological parameters are evolving areas in improving outcomes. Structured post-cardiac arrest care focused on targeted temperature management, optimization of hemodynamics, and careful intensive care unit management is associated with improved survival and neurological outcomes.

CONCLUSIONS AND RELEVANCE

Pediatric IHCA occurs frequently and has a high mortality rate. Early identification of risk, prevention, delivery of high-quality CPR, and post-cardiac arrest care can maximize the chances of achieving favorable outcomes. More research in this field is warranted.

Pediatric Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations (CoSTR) for pediatric life support is based on the most extensive evidence evaluation ever performed by the Pediatric Life Support Task Force. Three types of evidence evaluation were used in this review: systematic reviews, scoping reviews, and evidence updates. Per agreement with the evidence evaluation recommendations of the International Liaison Committee on Resuscitation, only systematic reviews could result in a new or revised treatment recommendation. Systematic reviews performed for this 2020 CoSTR for pediatric life support included the topics of sequencing of airway-breaths-compressions versus compressions-airway-breaths in the delivery of pediatric basic life support, the initial timing and dose intervals for epinephrine administration during resuscitation, and the targets for oxygen and carbon dioxide levels in pediatric patients after return of spontaneous circulation. The most controversial topics included the initial timing and dose intervals of epinephrine administration (new treatment recommendations were made) and the administration of fluid for infants and children with septic shock (this latter topic was evaluated by evidence update). All evidence reviews identified the paucity of pediatric data and the need for more research involving resuscitation of infants and children.

Pediatric Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations

This 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations (CoSTR) for pediatric life support is based on the most extensive evidence evaluation ever performed by the Pediatric Life Support Task Force. Three types of evidence evaluation were used in this review: systematic reviews, scoping reviews, and evidence updates. Per agreement with the evidence evaluation recommendations of the International Liaison Committee on Resuscitation, only systematic reviews could result in a new or revised treatment recommendation. Systematic reviews performed for this 2020 CoSTR for pediatric life support included the topics of sequencing of airway-breaths-compressions versus compressions-airway-breaths in the delivery of pediatric basic life support, the initial timing and dose intervals for epinephrine administration during resuscitation, and the targets for oxygen and carbon dioxide levels in pediatric patients after return of spontaneous circulation. The most controversial topics included the initial timing and dose intervals of epinephrine administration (new treatment recommendations were made) and the administration of fluid for infants and children with septic shock (this latter topic was evaluated by evidence update). All evidence reviews identified the paucity of pediatric data and the need for more research involving resuscitation of infants and children.

More Than 500 Kids Could Be Saved Each Year! Ten Consensus Actions to Improve Quality of Pediatric Resuscitation in DACH-Countries (Austria, Germany, and Switzerland)

• Quality and outcome of pediatric resuscitation often does not achieve recommended goals. • Quality improvement initiatives with the aim of better survival rates and decreased morbidity of resuscitated children are urgently needed. • These initiatives should include an action framework for a comprehensive, fundamental, and interprofessional reorientation of clinical and organizational structures concerning resuscitation and post-resuscitation care of children. • The authors of this DACH position statement suggest the implementation of 10 evidence-based actions (for out-of-hospital and in-house cardiac arrests) that should improve survival rates and decrease morbidity of resuscitated children with better neurological outcome and quality of life.

Pediatric Cardiac Arrest Resuscitation

Pediatric cardiac arrest is a relatively rare but devastating presentation in infants and children. In contrast to adult patients, in whom a primary cardiac dysrhythmia is the most likely cause of cardiac arrest, pediatric patients experience cardiovascular collapse most frequently after an initial respiratory arrest. Aggressive treatment in the precardiac arrest state should be initiated to prevent deterioration and should focus on support of oxygenation, ventilation, and hemodynamics, regardless of the presumed cause. Unfortunately, outcomes for pediatric cardiac arrest, whether in hospital or out of hospital, continue to be poor.

Oxygenation and ventilation targets after cardiac arrest: A systematic review and meta-analysis

AIM

To perform a systematic review and meta-analysis of the literature on oxygenation and ventilation targets after successful resuscitation from cardiac arrest in order to inform an update of international guidelines.

METHODS

The review was performed according to PRISMA and registered on PROSPERO (ID: X). Medline, EMBASE, and the Cochrane Library were searched on August 22, 2019. The population included both adult and pediatric patients with cardiac arrest. Two investigators reviewed abstracts, extracted data, and assessed the risk of bias. Meta-analyses were performed for studies without excessive bias. Certainty of evidence was evaluated using GRADE.

RESULTS

We included 7 trials and 36 observational studies comparing oxygenation or ventilation targets. Most of the trials and observational studies included adults with out-of-hospital cardiac arrest. There were 6 observational studies in children. Bias for trials ranged from low to high risk, with group imbalances and blinding being primary concerns. Bias for observational studies was rated as serious or critical risk with confounding and exposure classification being primary sources of bias. Meta-analyses including two trials comparing low vs high oxygen therapy and two trials comparing hypercapnia vs no hypercapnia were inconclusive. Point estimates of individual studies generally favored normoxemia and normocapnia over hyper- or hypoxemia and hyper- or hypocapnia.

CONCLUSIONS

We identified a large number of studies related to oxygenation and ventilation targets in cardiac arrest. The majority of studies did not reach statistical significance and were limited by excessive risk of bias. Point estimates of individual studies generally favored normoxemia and normocapnia.

Early Hyperoxemia and Outcome Among Critically Ill Children

OBJECTIVE

To identify whether a high PaO2 (hyperoxemia) at the time of presentation to the PICU is associated with in-hospital mortality.

DESIGN

Single-center observational study.

SETTING

Quaternary-care PICU.

PATIENTS

Encounters admitted between January 1, 2009, and December 31, 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Encounters with a measured PaO2 were included. To account for severity of illness upon presentation, we calculated a modified Pediatric Risk of Mortality IV score excluding PaO2 for each encounter, calibrated for institutional data. Logistic regression was used to determine whether hyperoxemia (PaO2 ≥ 300 torr [39.99 kPa]) in the 12 hours surrounding PICU admission was associated with in-hospital mortality. We reperformed our analysis using a cutoff for hyperoxemia obtained by comparisons of observed versus predicted mortality when encounters were classified by highest PaO2 in 50 torr (6.67 kPa) bins. Results are reported as adjusted odds ratios with 95% CIs. Of 23,719 encounters, 4,093 had a PaO2 recorded in the period -6 to +6 hours after admission. Two hundred seventy-four of 4,093 (6.7%) had in-hospital mortality. The prevalence of hyperoxemia increased with rising modified Pediatric Risk of Mortality IV and was not associated with mortality in multivariable models (adjusted odds ratio, 1.38; 95% CI, 0.98-1.93). When using a higher cutoff of hyperoxemia derived from comparison of observed versus predicted rates of mortality of greater than or equal to 550 torr (73.32 kPa), hyperoxemia was associated with mortality (adjusted odds ratio, 2.78; 95% CI, 2.54-3.05).

CONCLUSIONS

A conventional threshold for hyperoxemia at presentation to the PICU was not associated with in-hospital mortality in a model using a calibrated acuity score. Extreme states of hyperoxemia (≥ 73.32 kPa) were significantly associated with in-hospital mortality. Prospective research is required to identify if hyperoxemia before and/or after PICU admission contributes to poor outcomes.

Pediatric Post–Cardiac Arrest Care: A Scientific Statement From the American Heart Association

Successful resuscitation from cardiac arrest results in a post–cardiac arrest syndrome, which can evolve in the days to weeks after return of sustained circulation. The components of post–cardiac arrest syndrome are brain injury, myocardial dysfunction, systemic ischemia/reperfusion response, and persistent precipitating pathophysiology. Pediatric post–cardiac arrest care focuses on anticipating, identifying, and treating this complex physiology to improve survival and neurological outcomes. This scientific statement on post–cardiac arrest care is the result of a consensus process that included pediatric and adult emergency medicine, critical care, cardiac critical care, cardiology, neurology, and nursing specialists who analyzed the past 20 years of pediatric cardiac arrest, adult cardiac arrest, and pediatric critical illness peer-reviewed published literature. The statement summarizes the epidemiology, pathophysiology, management, and prognostication after return of sustained circulation after cardiac arrest, and it provides consensus on the current evidence supporting elements of pediatric post–cardiac arrest care.

Association of Severe Hyperoxemia Events and Mortality Among Patients Admitted to a Pediatric Intensive Care Unit

Importance

A high Pao2, termed hyperoxemia, is postulated to have deleterious health outcomes. To date, the association between hyperoxemia during the ongoing management of critical illness and mortality has been incompletely evaluated in children.

Objective

To examine whether severe hyperoxemia events are associated with mortality among patients admitted to a pediatric intensive care unit (PICU).

Design, Setting, and Participants

A retrospective cohort study was conducted over a 10-year period (January 1, 2009, to December 31, 2018); all 23 719 PICU encounters at a quaternary children's hospital with a documented arterial blood gas measurement were evaluated.

Exposures

Severe hyperoxemia, defined as Pao2 level greater than or equal to 300 mm Hg (40 kPa).

Main Outcomes and Measures

The highest Pao2 values during hospitalization were dichotomized according to the definition of severe hyperoxemia and assessed for association with in-hospital mortality using logistic regression models incorporating a calibrated measure of multiple organ dysfunction, extracorporeal life support, and the total number of arterial blood gas measurements obtained during an encounter.

Results

Of 23 719 PICU encounters during the inclusion period, 6250 patients (13 422 [56.6%] boys; mean [SD] age, 7.5 [6.6] years) had at least 1 measured Pao2 value. Severe hyperoxemia was independently associated with in-hospital mortality (adjusted odds ratio [aOR], 1.78; 95% CI, 1.36-2.33; P < .001). Increasing odds of in-hospital mortality were observed with 1 (aOR, 1.47; 95% CI, 1.05-2.08; P = .03), 2 (aOR, 2.01; 95% CI, 1.27-3.18; P = .002), and 3 or more (aOR, 2.53; 95% CI, 1.62-3.94; P < .001) severely hyperoxemic Pao2 values obtained greater than or equal to 3 hours apart from one another compared with encounters without hyperoxemia. A sensitivity analysis examining the hypothetical outcomes of residual confounding indicated that an unmeasured binary confounder with an aOR of 2 would have to be present in 37% of the encounters with severe hyperoxemia and 0% of the remaining cohort to fail to reject the null hypothesis (aOR of severe hyperoxemia, 1.31; 95% CI, 0.99-1.72).

Conclusions and Relevance

Greater numbers of severe hyperoxemia events appeared to be associated with increased mortality in this large, diverse cohort of critically ill children, supporting a possible exposure-response association between severe hyperoxemia and outcome in this population. Although further prospective evaluation appears to be warranted, this study's findings suggest that guidelines for ongoing management of critically ill children should take into consideration the possible detrimental effects of severe hyperoxemia.

Management of post-cardiac arrest syndrome

Post-cardiac arrest syndrome is a complex and critical issue in resuscitated patients undergone cardiac arrest. Ischemic-reperfusion injury occurs in multiple organs due to the return of spontaneous circulation. Bundle of management practicies are required for post-cardiac arrest care. Early invasive coronary angiography should be considered to identify and treat coronary artery obstructive disease. Vasopressors such as norepinephrine and dobutamine are the first-line treatment for shock. Maintainance of oxyhemoglobin saturation greater than 94% but less than 100% is recommended to avoid fatality. Target temperature therapeutic hypothermia helps to resuscitated patients. Strict temperature control is required and is maintained with the help of cooling devices and monitoring the core temperature. Montorings include electrocardiogram, oxymetry, capnography, and electroencephalography (EEG) along with blood pressue, temprature, and vital signs. Seizure should be treated if EEG shows evidence of seizure or epileptiform activity. Clinical neurologic examination and magnetic resonance imaging are considered to predict neurological outcome. Glycemic control and metabolic management are favorable for a good neurological outcome. Recovery from acute kidney injury is essential for survival and a good neurological outcome.

Targeted Temperature Management and Postcardiac arrest Care

Despite recent advances, care of the post-cardiac arrest patient remains a challenge. In this article, the authors discuss an approach to the initial care of post-cardiac arrest patients with particular focus on targeted temperature management (TTM). The article starts with history, physiologic rationale, and the major randomized controlled trials that have shaped guidelines for post-cardiac arrest care. It also reviews controversial topics, including TTM for nonshockable rhythms, TTM dose, and surface versus endovascular cooling. The article concludes with a brief review of other key aspects of post-arrest care: coronary angiography, hemodynamic optimization, ventilator management, and prognostication.

The acute respiratory distress syndrome after out-of-hospital cardiac arrest: Incidence, risk factors, and outcomes

OBJECTIVE

To define the incidence of the acute respiratory distress syndrome (ARDS) following out-of-hospital cardiac arrest (OHCA) and characterize its impact on outcome.

METHODS

This was a retrospective cohort study conducted at two urban, tertiary, academic hospitals from 2007 to 2014. We included adults with non-traumatic OHCA and survived for ≥48 h. Patients who received mechanical ventilation for ≥24 h, had 2 consecutive arterial blood gases with a ratio of the partial pressure of oxygen to the fraction of inspired oxygen ≤300, and bilateral radiographic opacities within 48 h of hospital admission were defined as having ARDS. We examined the associations between ARDS and outcome using multivariable analyses and performed sensitivity analyses excluding patients with evidence of cardiac dysfunction.

RESULTS

Of 978 OHCA patients transported to the study hospitals, 600 were mechanically ventilated and survived ≥48 h. A total of 287 (48%, 95% CI 44-52%) met criteria for ARDS within 48 h of admission. There were no differences in demographics, OHCA etiology, or cardiac rhythm according to ARDS status. Patients with ARDS had higher hospital mortality, longer ICU stays, more ventilator days, and were less likely to survive with full neurologic recovery. Upon excluding patients with cardiac dysfunction, the incidence of ARDS was unchanged.

CONCLUSION

Nearly half of initial OHCA survivors develop ARDS within 48 h of hospital admission. ARDS was associated with poor outcome and increased resource utilization. OHCA should be considered among the traditional ARDS risk factors.

Critical Care of the Post-Cardiac Arrest Patient

The post-cardiac arrest syndrome is a highly inflammatory state characterized by organ dysfunction, systemic ischemia and reperfusion injury, and persistent precipitating pathology. Early critical care should focus on identifying and treating arrest etiology and minimizing further injury to the brain and other organs by optimizing perfusion, oxygenation, ventilation, and temperature. Patients should be treated with targeted temperature management, although the exact temperature goal is not clear. No earlier than 72 hours after rewarming, prognostication using a multimodal approach should inform discussions with families regarding likely neurologic outcome.

Admission Hyperoxia Is a Risk Factor for Mortality in Pediatric Intensive Care

OBJECTIVES

To determine whether the association between hyperoxia and increased risk-adjusted mortality in adult intensive care patients is also observed in a pediatric intensive care population.

DESIGN

Single-center retrospective analysis of admissions to ICU over a 5-year period commencing January 1, 2012, examining the relationship between PaO2 measured within the first hour of admission and risk-adjusted mortality. Standardized mortality rates were calculated using the Pediatric Index of Mortality-3, and patients were grouped into 50 mm Hg (6.67 kPa) PaO2 bands to assess the relationship between initial PaO2 and risk-adjusted mortality.

SETTING

Tertiary PICU with 17 beds and 1,100 annual admissions located in metropolitan Sydney, Australia.

PATIENTS

A total of 1,447 patients 0-18 years old with PaO2 recorded at admission to the ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

There were 5,176 patients admitted to the ICU during the study period and 1,447 (28%) with PaO2 recorded at admission. A U-shaped relationship between raw mortality and admission PaO2 was observed, with lowest mortality (2.3% and 2.6%, respectively) observed in the 101-150 (13.5-20.0 kPa) and 151-200 mm Hg (20.1-26.7 kPa) bands and the highest mortality observed in patients with PaO2 less than 50 mm Hg (6.67 kPa) with mortality of 5.3%, or greater than 350 mm Hg (46.7 kPa) with mortality of 18.2%. Hyperoxia at admission was associated with an increase in risk-adjusted mortality, with polynomial regression indicating a strong correlation between PaO2 band and risk-adjusted outcome (r = 0.845). When included in a multivariate model that included the Pediatric Index of Mortality-3 variables, the odds ratio for hyperoxia (defined as PaO2 > 250 mm Hg [33.3 kPa]) predicting death was 2.66 (p = 0.047).

CONCLUSIONS

In this single-center study, hyperoxia at admission to the PICU was highly correlated with increased risk-adjusted mortality. Further investigation of these observations in a large multicenter cohort is warranted.

Singapore Paediatric Resuscitation Guidelines 2016

We present the revised 2016 Singapore paediatric resuscitation guidelines. The International Liaison Committee on Resuscitation's Pediatric Taskforce Consensus Statements on Science and Treatment Recommendations, as well as the updated resuscitation guidelines from the American Heart Association and European Resuscitation Council released in October 2015, were debated and discussed by the workgroup. The final recommendations for the Singapore Paediatric Resuscitation Guidelines 2016 were derived after carefully reviewing the current available evidence in the literature and balancing it with local clinical practice.

Cardiopulmonary Resuscitation in Infants and Children With Cardiac Disease: A Scientific Statement From the American Heart Association

Cardiac arrest occurs at a higher rate in children with heart disease than in healthy children. Pediatric basic life support and advanced life support guidelines focus on delivering high-quality resuscitation in children with normal hearts. The complexity and variability in pediatric heart disease pose unique challenges during resuscitation. A writing group appointed by the American Heart Association reviewed the literature addressing resuscitation in children with heart disease. MEDLINE and Google Scholar databases were searched from 1966 to 2015, cross-referencing pediatric heart disease with pertinent resuscitation search terms. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. The recommendations in this statement concur with the critical components of the 2015 American Heart Association pediatric basic life support and pediatric advanced life support guidelines and are meant to serve as a resuscitation supplement. This statement is meant for caregivers of children with heart disease in the prehospital and in-hospital settings. Understanding the anatomy and physiology of the high-risk pediatric cardiac population will promote early recognition and treatment of decompensation to prevent cardiac arrest, increase survival from cardiac arrest by providing high-quality resuscitations, and improve outcomes with postresuscitation care.

Hyperoxia and Hypocapnia During Pediatric Extracorporeal Membrane Oxygenation: Associations With Complications, Mortality, and Functional Status Among Survivors

OBJECTIVES

To determine the frequency of hyperoxia and hypocapnia during pediatric extracorporeal membrane oxygenation and their relationships to complications, mortality, and functional status among survivors.

DESIGN

Secondary analysis of data collected prospectively by the Collaborative Pediatric Critical Care Research Network.

SETTING

Eight Collaborative Pediatric Critical Care Research Network-affiliated hospitals.

PATIENTS

Age less than 19 years and treated with extracorporeal membrane oxygenation.

INTERVENTIONS

Hyperoxia was defined as highest PaO2 greater than 200 Torr (27 kPa) and hypocapnia as lowest PaCO2 less than 30 Torr (3.9 kPa) during the first 48 hours of extracorporeal membrane oxygenation. Functional status at hospital discharge was evaluated among survivors using the Functional Status Scale.

MEASUREMENTS AND MAIN RESULTS

Of 484 patients, 420 (86.7%) had venoarterial extracorporeal membrane oxygenation and 64 (13.2%) venovenous; 69 (14.2%) had extracorporeal membrane oxygenation initiated during cardiopulmonary resuscitation. Hyperoxia occurred in 331 (68.4%) and hypocapnia in 98 (20.2%). Hyperoxic patients had higher mortality than patients without hyperoxia (167 [50.5%] vs 48 [31.4%]; p < 0.001), but no difference in functional status among survivors. Hypocapnic patients were more likely to have a neurologic event (49 [50.0%] vs 143 (37.0%]; p = 0.021) or hepatic dysfunction (49 [50.0%] vs 121 [31.3%]; p < 0.001) than patients without hypocapnia, but no difference in mortality or functional status among survivors. On multivariable analysis, factors independently associated with increased mortality included highest PaO2 and highest blood lactate concentration in the first 48 hours of extracorporeal membrane oxygenation, congenital diaphragmatic hernia, and being a preterm neonate. Factors independently associated with lower mortality included meconium aspiration syndrome.

CONCLUSIONS

Hyperoxia is common during pediatric extracorporeal membrane oxygenation and associated with mortality. Hypocapnia appears to occur less often and although associated with complications, an association with mortality was not observed.

Frequency of Desaturation and Association With Hemodynamic Adverse Events During Tracheal Intubations in PICUs

OBJECTIVES

Oxygen desaturation during tracheal intubation is known to be associated with adverse ICU outcomes in critically ill children. We aimed to determine the occurrence and severity of desaturation during tracheal intubations and the association with adverse hemodynamic tracheal intubation-associated events.

DESIGN

Retrospective cohort study as a part of the National Emergency Airway Registry for Children Network's quality improvement project from January 2012 to December 2014.

SETTING

International PICUs.

PATIENTS

Critically ill children younger than 18 years undergoing primary tracheal intubations in the ICUs.

INTERVENTIONS

tracheal intubation processes of care and outcomes were prospectively collected using standardized operational definitions. We defined moderate desaturation as oxygen saturation less than 80% and severe desaturation as oxygen saturation less than 70% during tracheal intubation procedures in children with initial oxygen saturation greater than 90% after preoxygenation. Adverse hemodynamic tracheal intubation-associated event was defined as cardiac arrests, hypo or hypertension requiring intervention, and dysrhythmia.

MEASUREMENTS AND MAIN RESULTS

A total of 5,498 primary tracheal intubations from 31 ICUs were reported. Moderate desaturation was observed in 19.3% associated with adverse hemodynamic tracheal intubation-associated events (9.8% among children with moderate desaturation vs 4.4% without desaturation; p < 0.001). Severe desaturation was observed in 12.9% of tracheal intubations, also significantly associated with hemodynamic tracheal intubation-associated events. After adjusting for patient, provider, and practice factors, the occurrence of moderate desaturation was independently associated with hemodynamic tracheal intubation-associated events: adjusted odds ratio 1.83 (95% CI, 1.34-2.51; p < 0.001). The occurrence of severe desaturation was also independently associated with hemodynamic tracheal intubation-associated events: adjusted odds ratio 2.16 (95% CI, 1.54-3.04; p < 0.001). Number of tracheal intubation attempts was also significantly associated with the frequency of moderate and severe desaturations (p < 0.001).

CONCLUSIONS

In this large tracheal intubation quality improvement database, we found moderate and severe desaturation are reported among 19% and 13% of all tracheal intubation encounters. Moderate and severe desaturations were independently associated with the occurrence of adverse hemodynamic events. Future quality improvement interventions may focus to reduce desaturation events.

Initial blood pH during cardiopulmonary resuscitation in out-of-hospital cardiac arrest patients: a multicenter observational registry-based study

BACKGROUND

When an out-of-hospital cardiac arrest (OHCA) patient receives cardiopulmonary resuscitation (CPR) in the emergency department (ED), blood laboratory test results can be obtained by using point-of-care testing during CPR. In the present study, the relationship between blood laboratory test results during CPR and outcomes of OHCA patients was investigated.

METHODS

This study was a multicenter retrospective analysis of prospective registered data that included 2716 OHCA patients. Data from the EDs of three university hospitals in different areas were collected from January 2009 to December 2014. Univariate and multivariable analyses were conducted to elucidate the factors associated with survival to discharge and neurological outcomes. A final analysis was conducted by including patients who had no prehospital return of spontaneous circulation and those who underwent rapid blood laboratory examination during CPR.

RESULTS

Overall, 2229 OHCA patients were included in the final analysis. Among them, the rate of survival to discharge and a good Cerebral Performance Categories Scale score were 14% and 4.4%, respectively. The pH level was independently related to survival to hospital discharge (adjusted OR 6.287, 95% CI 2.601-15.197; p < 0.001) and good neurological recovery (adjusted OR 15.395, 95% CI 3.439-68.911; p < 0.001). None of the neurologically intact patients had low pH levels (< 6.8) or excessive potassium levels (> 8.5 mEq/L) during CPR.

CONCLUSIONS

Among the blood laboratory test results during CPR of OHCA patients, pH and potassium levels were observed as independent factors associated with survival to hospital discharge, and pH level was considered as an independent factor related to neurological recovery.

Ventilation during cardiopulmonary resuscitation in children: a survey on clinical practice

BACKGROUND

This study aimed to investigate the ventilation practice during cardiopulmonary resuscitation (CPR) and after return of spontaneous circulation (ROSC) in children.

METHODS

An online survey of CPR practices was designed and sent to healthcare professionals treating children.

RESULTS

A total of 477 healthcare professionals from 46 countries responded to this survey; 92.7% were physicians and 64.2% worked in pediatric intensive care units. Specific CPR guidelines were used by 97.7% of respondents. The respiratory rate most frequently used for children over 12 months was 13 to 20 respirations per minute (rpm) (46% in intubated and 41.8% in non-intubated). For infants under 12 months, the most frequently used respiratory rate was 21 to 30 rpm in intubated patients (37.3%): in non-intubated infants, 13 to 20 rpm (26.5%) and 21 to 30 rpm (26.5%) were used with the same frequency. In North America, the respiratory rate most widely used was 7 to 12 rpm; higher rates (13 to 20 rpm and 21 to 30 rpm) were used in Europe and Latin America (P<0.001). After ROSC, no significant differences in the respiratory rates used were found between the continents. More than 40% of healthcare professionals had a target oxygen saturation below 94%; more than 10% used a target arterial PCO₂ below 35 mmHg and more than 13% above 45 mmHg.

CONCLUSIONS

There is considerable variation in the management of ventilation of children in cardiac arrest, and international recommendations are not being followed in a high percentage of cases.

Ventilator Management and Respiratory Care After Cardiac Arrest: Oxygenation, Ventilation, Infection, and Injury

Return of spontaneous circulation after cardiac arrest results in a systemic inflammatory state called the post-cardiac arrest syndrome, which is characterized by oxidative stress, coagulopathy, neuronal injury, and organ dysfunction. Perturbations in oxygenation and ventilation may exacerbate secondary injury after cardiac arrest and have been shown to be associated with poor outcome. Further, patients who experience cardiac arrest are at risk for a number of other pulmonary complications. Up to 70% of patients experience early infection after cardiac arrest, and the respiratory tract is the most common source. Vigilance for early-onset pneumonia, as well as aggressive diagnosis and early antimicrobial agent administration are important components of critical care in this population. Patients who experience cardiac arrest are at risk for the development of ARDS. Risk factors include aspiration, pulmonary contusions (from chest compressions), systemic inflammation, and reperfusion injury. Early evidence suggests that they may benefit from ventilation with low tidal volumes. Meticulous attention to mechanical ventilation, early assessment and optimization of respiratory gas exchange, and therapies targeted at potential pulmonary complications may improve outcomes after cardiac arrest.

Cardiopulmonary Resuscitation in Pediatric and Cardiac Intensive Care Units

Approximately 5000 to 10,000 children suffer an in-hospital cardiac arrest requiring cardiopulmonary resuscitation (CPR) each year in the United States. Importantly, 2% to 6% of all children admitted to pediatric intensive care units (ICUs) receive CPR, as do 4% to 6% of children admitted to pediatric cardiac ICUs. Survival from pediatric ICU cardiac arrest has improved substantially during the past 20 years presumably due to improved training methods, CPR quality, and post-resuscitation care. Extracorporeal life support CPR remains an important treatment option for both cardiac and noncardiac ICU patients.

Interpretation of epidemiologic studies very often lacked adequate consideration of confounding

BACKGROUND AND OBJECTIVE

Confounding bias is a most pervasive threat to validity of observational epidemiologic research. We assessed whether authors of observational epidemiologic studies consider confounding bias when interpreting the findings.

STUDY DESIGN AND SETTING

We randomly selected 120 cohort or case-control studies published in 2011 and 2012 by the general medical, epidemiologic, and specialty journals with the highest impact factors. We used Web of Science to assess citation metrics through January 2017.

RESULTS

Sixty-eight studies (56.7%, 95% confidence interval: 47.8-65.5%) mentioned "confounding" in the Abstract or Discussion sections, another 20 (16.7%; 10.0-23.3%) alluded to it, and there was no mention or allusion at all in 32 studies (26.7%; 18.8-34.6%). Authors often acknowledged that for specific confounders, there was no adjustment (34 studies; 28.3%) or deem it possible or likely that confounding affected their main findings (29 studies; 24.2%). However, only two studies (1.7%; 0-4.0%) specifically used the words "caution" or "cautious" for the interpretation because of confounding-related reasons and eventually only four studies (3.3%; 0.1-6.5%) had limitations related to confounding or any other bias in their Conclusions. Studies mentioning that the findings were possibly or likely affected by confounding were more frequently cited than studies with a statement that findings were unlikely affected (median 6.3 vs. 4.0 citations per year, P = 0.04).

CONCLUSIONS

Many observational studies lack satisfactory discussion of confounding bias. Even when confounding bias is mentioned, authors are typically confident that it is rather irrelevant to their findings and they rarely call for cautious interpretation. More careful acknowledgment of possible impact of confounding is not associated with lower citation impact.