Development of a bedside tool to predict time to death after withdrawal of life-sustaining therapies in infants and children

Advancing the Scientific Basis for Determining Death in Controlled Organ Donation After Circulatory Determination of Death

In controlled organ donation after circulatory determination of death (cDCDD), accurate and timely death determination is critical, yet knowledge gaps persist. Further research to improve the science of defining and determining death by circulatory criteria is therefore warranted. In a workshop sponsored by the National Heart, Lung, and Blood Institute, experts identified research opportunities pertaining to scientific, conceptual, and ethical understandings of DCDD and associated technologies. This article identifies a research strategy to inform the biomedical definition of death, the criteria for its determination, and circulatory death determination in cDCDD. Highlighting knowledge gaps, we propose that further research is needed to inform the observation period following cessation of circulation in pediatric and neonatal populations, the temporal relationship between the cessation of brain and circulatory function after the withdrawal of life-sustaining measures in all patient populations, and the minimal pulse pressures that sustain brain blood flow, perfusion, activity, and function. Additionally, accurate predictive tools to estimate time to asystole following the withdrawal of treatment and alternative monitoring modalities to establish the cessation of circulatory, brainstem, and brain function are needed. The physiologic and conceptual implications of postmortem interventions that resume circulation in cDCDD donors likewise demand attention to inform organ recovery practices. Finally, because jurisdictionally variable definitions of death and the criteria for its determination may impede collaborative research efforts, further work is required to achieve consensus on the physiologic and conceptual rationale for defining and determining death after circulatory arrest.

Pediatric Death After Withdrawal of Life-Sustaining Therapies: A Scoping Review

OBJECTIVES

Evaluate literature on the dying process in children after withdrawal of life sustaining measures (WLSM) in the PICU. We focused on the physiology of dying, prediction of time to death, impact of time to death, and uncertainty of the dying process on families, healthcare workers, and organ donation.

DATA SOURCES

MEDLINE, Embase, Cochrane Central Register of Controlled Trials, PsycINFO, CINAHL, and Web of Science.

STUDY SELECTION

We included studies that discussed the dying process after WLSM in the PICU, with no date or study type restrictions. We excluded studies focused exclusively on adult or neonatal populations, children outside the PICU, or on organ donation or adult/pediatric studies where pediatric data could not be isolated.

DATA EXTRACTION

Inductive qualitative content analysis was performed.

DATA SYNTHESIS

Six thousand two hundred twenty-five studies were screened and 24 included. Results were grouped into four categories: dying process, perspectives of healthcare professionals and family, WLSM and organ donation, and recommendations for future research. Few tools exist to predict time to death after WLSM in children. Most deaths after WLSM occur within 1 hour and during this process, healthcare providers must offer support to families regarding logistics, medications, and expectations. Providers describe the unpredictability of the dying process as emotionally challenging and stressful for family members and staff; however, no reports of families discussing the impact of time to death prediction were found. The unpredictability of death after WLSM makes families less likely to pursue donation. Future research priorities include developing death prediction tools of tools, provider and parental decision-making, and interventions to improve end-of-life care.

CONCLUSIONS

The dying process in children is poorly understood and understudied. This knowledge gap leaves families in a vulnerable position and the clinical team without the necessary tools to support patients, families, or themselves. Improving time to death prediction after WLSM may improve care provision and enable identification of potential organ donors.

Analgesia and Sedation at Terminal Extubation: A Secondary Analysis From Death One Hour After Terminal Extubation Study Data

OBJECTIVES

To describe the doses of opioids and benzodiazepines administered around the time of terminal extubation (TE) to children who died within 1 hour of TE and to identify their association with the time to death (TTD).

DESIGN

Secondary analysis of data collected for the Death One Hour After Terminal Extubation study.

SETTING

Nine U.S. hospitals.

PATIENTS

Six hundred eighty patients between 0 and 21 years who died within 1 hour after TE (2010-2021).

MEASUREMENTS AND MAIN RESULTS

Medications included total doses of opioids and benzodiazepines 24 hours before and 1 hour after TE. Correlations between drug doses and TTD in minutes were calculated, and multivariable linear regression performed to determine their association with TTD after adjusting for age, sex, last recorded oxygen saturation/F io2 ratio and Glasgow Coma Scale score, inotrope requirement in the last 24 hours, and use of muscle relaxants within 1 hour of TE. Median age of the study population was 2.1 years (interquartile range [IQR], 0.4-11.0 yr). The median TTD was 15 minutes (IQR, 8-23 min). Forty percent patients (278/680) received either opioids or benzodiazepines within 1 hour after TE, with the largest proportion receiving opioids only (23%, 159/680). Among patients who received medications, the median IV morphine equivalent within 1 hour after TE was 0.75 mg/kg/hr (IQR, 0.3-1.8 mg/kg/hr) ( n = 263), and median lorazepam equivalent was 0.22 mg/kg/hr (IQR, 0.11-0.44 mg/kg/hr) ( n = 118). The median morphine equivalent and lorazepam equivalent rates after TE were 7.5-fold and 22-fold greater than the median pre-extubation rates, respectively. No significant direct correlation was observed between either opioid or benzodiazepine doses before or after TE and TTD. After adjusting for confounding variables, regression analysis also failed to show any association between drug dose and TTD.

CONCLUSIONS

Children after TE are often prescribed opioids and benzodiazepines. For patients dying within 1 hour of TE, TTD is not associated with the dose of medication administered as part of comfort care.

Predicting Time to Death After Withdrawal of Life-Sustaining Treatment in Children

Accurately predicting time to death after withdrawal of life-sustaining treatment is valuable for family counseling and for identifying candidates for organ donation after cardiac death. This topic has been well studied in adults, but literature is scant in pediatrics. The purpose of this report is to assess the performance and clinical utility of the available tools for predicting time to death after treatment withdrawal in children.

Comparison of pediatric brain-dead donors to donation after circulatory death donors in the United States

In pediatrics, an increasing need for transplantable organs exists. This study aimed to describe the epidemiology of pediatric deceased donors in the United States. This retrospective observational study utilized data from the Organ Procurement and Transplantation Network (OPTN) from 2000 to 2015. Patients were stratified based on method of organ donation. Demographic variables and mechanism of death were then compared. A total of 14,481 deceased pediatric organ donors, donation after brain death (DBD) and donation after circulatory death (DCD), were included in the study, of which 8% were DCD donors. A significant difference (p<0.001) existed between the two donor groups with respect to ethnicity and mechanism of death. The annual trend of DCD and DBD donors showed an inverse relationship. During the 15-year study period the number of DBD donors decreased from 985 to 785 per year while DCD donors increased from 15 to 146 per year. As well, overall organs transplanted per year decreased from 3,475 to 3,117 over the 15-year study period. Significant differences exist between pediatric DBD donors and DCD donors, specifically with respect to ethnicity and mechanism of death. The number of pediatric DBD donors is decreasing while the number of pediatric DCD is slowly rising, making it increasingly important to be able to characterize these donors to better identify eligible DCD donors to optimize organ utilization.

Machine Learning to Predict Cardiac Death Within 1 Hour After Terminal Extubation

OBJECTIVES

Accurate prediction of time to death after withdrawal of life-sustaining therapies may improve counseling for families and help identify candidates for organ donation after cardiac death. The study objectives were to: 1) train a long short-term memory model to predict cardiac death within 1 hour after terminal extubation, 2) calculate the positive predictive value of the model and the number needed to alert among potential organ donors, and 3) examine associations between time to cardiac death and the patient's characteristics and physiologic variables using Cox regression.

DESIGN

Retrospective cohort study.

SETTING

PICU and cardiothoracic ICU in a tertiary-care academic children's hospital.

PATIENTS

Patients 0-21 years old who died after terminal extubation from 2011 to 2018 (n = 237).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The median time to death for the cohort was 0.3 hours after terminal extubation (interquartile range, 0.16-1.6 hr); 70% of patients died within 1 hour. The long short-term memory model had an area under the receiver operating characteristic curve of 0.85 and a positive predictive value of 0.81 at a sensitivity of 94% when predicting death within 1 hour of terminal extubation. About 39% of patients who died within 1 hour met organ procurement and transplantation network criteria for liver and kidney donors. The long short-term memory identified 93% of potential organ donors with a number needed to alert of 1.08, meaning that 13 of 14 prepared operating rooms would have yielded a viable organ. A Cox proportional hazard model identified independent predictors of shorter time to death including low Glasgow Coma Score, high Pao2-to-Fio2 ratio, low-pulse oximetry, and low serum bicarbonate.

CONCLUSIONS

Our long short-term memory model accurately predicted whether a child will die within 1 hour of terminal extubation and may improve counseling for families. Our model can identify potential candidates for donation after cardiac death while minimizing unnecessarily prepared operating rooms.

Palliative extubation: five-year experience in a pediatric hospital

OBJECTIVE

To present the characteristics of pediatric patients with chronic and irreversible diseases submitted to palliative extubation.

METHOD

This is a descriptive analysis of a series of patients admitted to a public pediatric hospital, with chronic and irreversible diseases, permanently dependent on ventilatory support, who underwent palliative extubation between April 2014 and May 2019. The following information was collected from the medical records: demographic data, diagnosis, duration and type of mechanical ventilation; date, time, and place of palliative extubation; medications used; symptoms observed; and hospital outcome.

RESULTS

A total of 19 patients with a mean age of 2.2 years were submitted to palliative extubation. 68.4% of extubations were performed in the ICU; 11 patients (57.9%) died in the hospital. The time between mechanical ventilation withdrawal and in-hospital death ranged from 15minutes to five days. Thirteen patients used an orotracheal tube and the others used tracheostomy. The main symptoms were dyspnea and pain, and the main drugs used to control symptoms were opioids and benzodiazepines.

CONCLUSIONS

It was not possible to identify predictors of in-hospital death after ventilatory support withdrawal. Palliative extubation requires specialized care, with the presence and availability of a multidisciplinary team with adequate training in symptom control and palliative care.

First pediatric organ donation after circulatory determination of death in Singapore: Facing challenges in the absence of a local practice guideline

Pediatric organ donation represents only a low proportion of overall organ donation in many parts of world, unable to match the needs for pediatric organ transplantation. Pediatric organ donation after circulatory determination of death (DCD) is increasingly explored in pediatric transplantation, as it increases the availability of organ grafts. A 6-year-old Caucasian boy with a history of arteriovenous malformation presented with a catastrophic intracranial bleed, resulting in severe brainstem dysfunction despite maximal medical and surgical measures. He did not fulfill the criteria for brain death, which must be met for pediatric organ donation in Singapore. Due to parental request, his organs were donated after withdrawal of life support and determination of death by circulatory criteria. Pediatric organ DCD poses many challenges in the pediatric population, especially in the absence of a local practice guideline. We present the first case of a pediatric organ DCD that has occurred in Singapore. Further work is needed, particularly in establishing a national policy for pediatric organ DCD and increasing overall awareness and acceptance toward pediatric organ donations.

Canadian Guidelines for Controlled Pediatric Donation After Circulatory Determination of Death-Summary Report

OBJECTIVES

Create trustworthy, rigorous, national clinical practice guidelines for the practice of pediatric donation after circulatory determination of death in Canada.

METHODS

We followed a process of clinical practice guideline development based on World Health Organization and Canadian Medical Association methods. This included application of Grading of Recommendations Assessment, Development, and Evaluation methodology. Questions requiring recommendations were generated based on 1) 2006 Canadian donation after circulatory determination of death guidelines (not pediatric specific), 2) a multidisciplinary symposium of national and international pediatric donation after circulatory determination of death leaders, and 3) a scoping review of the pediatric donation after circulatory determination of death literature. Input from these sources drove drafting of actionable questions and Good Practice Statements, as defined by the Grading of Recommendations Assessment, Development, and Evaluation group. We performed additional literature reviews for all actionable questions. Evidence was assessed for quality using Grading of Recommendations Assessment, Development, and Evaluation and then formulated into evidence profiles that informed recommendations through the evidence-to-decision framework. Recommendations were revised through consensus among members of seven topic-specific working groups and finalized during meetings of working group leads and the planning committee. External review was provided by pediatric, critical care, and critical care nursing professional societies and patient partners.

RESULTS

We generated 63 Good Practice Statements and seven Grading of Recommendations Assessment, Development, and Evaluation recommendations covering 1) ethics, consent, and withdrawal of life-sustaining therapy, 2) eligibility, 3) withdrawal of life-sustaining therapy practices, 4) ante and postmortem interventions, 5) death determination, 6) neonatal pediatric donation after circulatory determination of death, 7) cardiac and innovative pediatric donation after circulatory determination of death, and 8) implementation. For brevity, 48 Good Practice Statement and truncated justification are included in this summary report. The remaining recommendations, detailed methodology, full Grading of Recommendations Assessment, Development, and Evaluation tables, and expanded justifications are available in the full text report.

CONCLUSIONS

This process showed that rigorous, transparent clinical practice guideline development is possible in the domain of pediatric deceased donation. Application of these recommendations will increase access to pediatric donation after circulatory determination of death across Canada and may serve as a model for future clinical practice guideline development in deceased donation.

Challenges of paediatric organ donation

Paediatric organ donation represents a small fraction of overall organ donation in Australia and New Zealand and indeed world-wide. Many factors contribute to low donation rates including low paediatric intensive care mortality, consent rates and medical suitability relating to disease, age and size. In the past decade, the re-emergence of donation after circulatory death has changed the landscape for the paediatric population. This article reviews the current status and challenges of organ donation for the paediatric population.

[Limitation of the therapeutic effort in pediatric intensive care]

Pediatric intensive care is a relatively new medical specialty, which has experienced significant technological advances in recent years. These developments have led to a prolongation of the dying process, with additional suffering for patients and their families, creating complex situations, and often causing a painful life extension. The term, limitation of the therapeutic effort refers to the adequacy and/or proportionality of the treatment, trying to avoid obstinacy and futility. The English literature does not talk about limitation of treatments, but instead the terms, withholding or withdrawal of life-sustaining treatment, are used. The removal or the non-installation of certain life support measures and the absence of CPR are the types of limitation most used. Also, there is evidence of insufficient medical training in bioethics, which is essential, as most doctors in the PICU discuss and make decisions regarding the end of life without the opinion of bioethicists. This article attempts to review the current status of knowledge concerning the limitation of therapeutic efforts to support pediatric clinical work.

Pediatric Donation After Circulatory Determination of Death: A Scoping Review

OBJECTIVE

Although pediatric donation after circulatory determination of death is increasing in frequency, there are no national or international donation after circulatory determination of death guidelines specific to pediatrics. This scoping review was performed to map the pediatric donation after circulatory determination of death literature, identify pediatric donation after circulatory determination of death knowledge gaps, and inform the development of national or regional pediatric donation after circulatory determination of death guidelines.

DATA SOURCES

Terms related to pediatric donation after circulatory determination of death were searched in Embase and MEDLINE, as well as the non-MEDLINE sources in PubMed from 1980 to May 2014.

STUDY SELECTION

Seven thousand five hundred ninety-seven references were discovered and 85 retained for analysis. All references addressing pediatric donation after circulatory determination of death were considered. Exclusion criteria were articles that did not address pediatric patients, animal or laboratory studies, surgical techniques, and local pediatric donation after circulatory determination of death protocols. Narrative reviews and opinion articles were the most frequently discovered reference (25/85) and the few discovered studies were observational or qualitative and almost exclusively retrospective.

DATA EXTRACTION

Retained references were divided into themes and analyzed using qualitative methodology.

DATA SYNTHESIS

The main discovered themes were 1) studies estimating the number of potential pediatric donation after circulatory determination of death donors and their impact on donation; 2) ethical issues in pediatric donation after circulatory determination of death; 3) physiology of the dying process after withdrawal of life-sustaining therapy; 4) cardiac pediatric donation after circulatory determination of death; and 5) neonatal pediatric donation after circulatory determination of death. Donor estimates suggest that pediatric donation after circulatory determination of death will remain an event less common than brain death, albeit with the potential to substantially expand the existing organ donation pool. Limited data suggest outcomes comparable with organs donated after neurologic determination of death. Although there is continued debate around ethical aspects of pediatric donation after circulatory determination of death, all pediatric donation after circulatory determination of death publications from professional societies contend that pediatric donation after circulatory determination of death can be practiced ethically.

CONCLUSIONS

This review provides a comprehensive overview of the published literature related to pediatric donation after circulatory determination of death. In addition to informing the development of pediatric-specific guidelines, this review serves to highlight several important knowledge gaps in this topic.

Validation of a pediatric bedside tool to predict time to death after withdrawal of life support

AIM: To evaluate the accuracy of a tool developed to predict timing of death following withdrawal of life support in children.

METHODS: Pertinent variables for all pediatric deaths (age ≤ 21 years) from 1/2009 to 6/2014 in our pediatric intensive care unit (PICU) were extracted through a detailed review of the medical records. As originally described, a recently developed tool that predicts timing of death in children following withdrawal of life support (dallas predictor tool [DPT]) was used to calculate individual scores for each patient. Individual scores were calculated for prediction of death within 30 min (DPT30) and within 60 min (DPT60). For various resulting DPT30 and DPT60 scores, sensitivity, specificity and area under the receiver operating characteristic curve were calculated.

RESULTS: There were 8829 PICU admissions resulting in 132 (1.5%) deaths. Death followed withdrawal of life support in 70 patients (53%). After excluding subjects with insufficient data to calculate DPT scores, 62 subjects were analyzed. Average age of patients was 5.3 years (SD: 6.9), median time to death after withdrawal of life support was 25 min (range; 7 min to 16 h 54 min). Respiratory failure, shock and sepsis were the most common diagnoses. Thirty-seven patients (59.6%) died within 30 min of withdrawal of life support and 52 (83.8%) died within 60 min. DPT30 scores ranged from -17 to 16. A DPT30 score ≥ -3 was most predictive of death within that time period, with sensitivity = 0.76, specificity = 0.52, AUC = 0.69 and an overall classification accuracy = 66.1%. DPT60 scores ranged from -21 to 28. A DPT60 score ≥ -9 was most predictive of death within that time period, with sensitivity = 0.75, specificity = 0.80, AUC = 0.85 and an overall classification accuracy = 75.8%.

CONCLUSION: In this external cohort, the DPT is clinically relevant in predicting time from withdrawal of life support to death. In our patients, the DPT is more useful in predicting death within 60 min of withdrawal of life support than within 30 min. Furthermore, our analysis suggests optimal cut-off scores. Additional calibration and modifications of this important tool could help guide the intensive care team and families considering DCD.

Predicting time to death after withdrawal of life-sustaining therapy

PURPOSE

Predicting time to death following the withdrawal of life-sustaining therapy is difficult. Accurate predictions may better prepare families and improve the process of donation after circulatory death.

METHODS

We systematically reviewed any predictive factors for time to death after withdrawal of life support therapy.

RESULTS

Fifteen observational studies met our inclusion criteria. The primary outcome was time to death, which was evaluated to be within 60 min in the majority of studies (13/15). Additional time endpoints evaluated included time to death within 30, 120 min, and 10 h, respectively. While most studies evaluated risk factors associated with time to death, a few derived or validated prediction tools. Consistent predictors of time to death that were identified in five or more studies included the following risk factors: controlled ventilation, oxygenation, vasopressor use, Glasgow Coma Scale/Score, and brain stem reflexes. Seven unique prediction tools were derived, validated, or both across some of the studies. These tools, at best, had only moderate sensitivity to predicting the time to death. Simultaneous withdrawal of all support and physician opinion were only evaluated in more recent studies and demonstrated promising predictor capabilities.

CONCLUSIONS

While the risk factors controlled ventilation, oxygenation, vasopressors, level of consciousness, and brainstem reflexes have been most consistently found to be associated with time to death, the addition of novel predictors, such as physician opinion and simultaneous withdrawal of all support, warrant further investigation. The currently existing prediction tools are not highly sensitive. A more accurate and generalizable tool is needed to inform end-of-life care and enhance the predictions of donation after circulatory death eligibility.

Parental experiences and recommendations in donation after circulatory determination of death*

OBJECTIVE

To describe parents' experience of organ donation decision making in the case of donation after circulatory determination of death.

DESIGN

Qualitative exploratory analysis.

SETTING

Participants were recruited from the ICU of a single children's hospital located in the western United States.

PARTICIPANTS

Thirteen parents, 11 families who consented to donate their child's organs.

INTERVENTIONS

Interviews (average 82 min).

MEASUREMENTS AND MAIN RESULTS

Transcribed interviews were analyzed using the constant comparative method to identify themes that reflected similarities in parents' experiences. The themes we found included 1) factors contributing to parental decision making, 2) under the circumstances of the child dying, and 3) donation decision and its impact on parental grief. Factors that influenced the decision making all related to the child dying, including protecting the child's body and helping the child to die peacefully. Finally, parents made recommendations about the organ donation process, including empathy, attend to end-of-life concerns, and the provision of relevant information for donation decisions.

CONCLUSIONS

Parents' decision making was related directly to end-of-life experience and grief process. Providers need to orient to parents' end-of-life concerns to support parents' decision-making process and improve donation after circulatory determination of death procedures.

End-of-life care in the pediatric ICU

PURPOSE OF REVIEW

Pediatric ICUs frequently provide end-of-life (EOL) care to children. Our understanding of how EOL care is delivered to children and what constitutes effective care for dying children and their families in the ICU setting continues to evolve. This review identifies recent work describing events related to the death of a child in the ICU as well as interventional efforts to improve family and provider support.

RECENT FINDINGS

Pediatric ICUs (PICUs) often provide EOL care to children who die in the developed world. Areas of active investigation include identifying effective communication techniques, meeting the needs of patients and parents, and providing support to care providers.

SUMMARY

PICU practitioners are developing flexible and novel approaches to pediatric EOL care in the ICU setting.

No-touch time in donors after cardiac death (nonheart-beating organ donation)

PURPOSE OF REVIEW

To evaluate arterial pulselessness and the no-touch time of 5 min in defining irreversible cessation of cardiorespiratory functions in nonheart-beating donation (NHBD).

RECENT FINDINGS

Experimental NHBD studies identified compensatory neurohumoral mechanisms elicited in controlled terminal shock after withdrawal of life support. The neurohumoral mechanisms can preserve the viability of the cardiovascular and central nervous systems by: 1) diverting systemic blood flow from nonvital to vital organs; and 2) maintaining the perfusion pressure (arterial to venous pressure gradient minus interstitial tissue pressure) and microcirculation in vital organs. These compensatory mechanisms cause an early onset of splanchnic hypoperfusion and antemortem ischaemia of transplantable organs and preclude irreversible cessation of cardiorespiratory functions after brief periods of circulatory arrest. Allograft ischaemia is associated with primary nonfunction or delayed function in transplant recipients similar in aetiology to organ dysfunction in the postresuscitation phase of shock.

SUMMARY

In-situ perfusion can reverse ceased cardiac and neurological functions after arterial pulselessness and a no-touch time of 5 min in experimental models. Perfusion pressures are superior to arterial pulselessness in determining reversibility of ceased cardiac and neurological functions in circulatory arrest. Utilizing physiologically relevant circulatory and neurological parameters in NHBD protocols is essential for ascertaining irreversible cessation of vital functions in donors.