Apnea Testing for the Determination of Brain Death: A Systematic Scoping Review

Apnea Testing on Conventional Mechanical Ventilation During Brain Death Evaluation

INTRODUCTION

The use of continuous positive airway pressure has been shown to improve the tolerance of the apnea test, a critical component of brain death evaluation. The ability to deactivate the apnea backup setting has made apnea testing possible using several conventional mechanical ventilators. Our goal was to evaluate the safety and efficacy of apnea testing performed on mechanical ventilation, compared with the oxygen insufflation technique, for the determination of brain death.

METHODS

This was a retrospective study. In 2016, our institution approved a change in policy to permit apnea testing on conventional mechanical ventilation. We examined the records of consecutive adults who underwent apnea testing as part of the brain death evaluation process between 2016 and 2022. Using an apnea test technique was decided at the discretion of the attending physician. Outcomes were successful apnea test and the occurrence of patient instability during the test. This included oxygen desaturation (SpO2) < 90%, hypotension (mean arterial pressure < 65 mm Hg despite titration of vasopressor), cardiac arrhythmia, pneumothorax, and cardiac arrest.

RESULTS

Ninety-two adult patients underwent apnea testing during the study period: 58 (63%) with mechanical ventilation, 32 (35%) with oxygen insufflation, and 2 (2%) lacked documentation of technique. Apnea tests could not be completed successfully in 3 of 92 (3%) patients-two patients undergoing the oxygen insufflation technique (one patient with hypoxemia and one patient with hypotension) and one patient on mechanical ventilation (aborted for hemodynamic instability). Hypoxemia occurred in 4 of 32 (12.5%) patients with oxygen insufflation and in zero patients on mechanical ventilation (p = 0.01). Hypotension occurred during 3 of 58 (5%) tests with mechanical ventilation and 4 of 32 (12.5%) tests with oxygen insufflation (p = 0.24). In multivariate analysis, the use of oxygen insufflation was an independent predictor of patient instability during the apnea test (odds ratio 37.74, 95% confidence interval 2.74-520.14).

CONCLUSIONS

Apnea testing on conventional mechanical ventilation is feasible and offers several potential advantages over other techniques.

Brain death: A review of the latest guidelines

ABSTRACT

The incidence of brain death/death by neurologic criteria (BD/DNC) among all hospital deaths in the US is approximately 2.06% or 15,000-20,000 cases annually. This article reviews the latest guidelines for adult and pediatric BD/DNC. Although there have not been many changes to the guidelines over the years, BD/DNC guideline updates maintain consistency in determining BD/DNC.

Management of Potential Organ Donor: Indian Society of Critical Care Medicine-Position Statement

This position statement is documented based on the input from all contributing coauthors from the Indian Society of Critical Care Medicine (ISCCM), following a comprehensive literature review and summary of current scientific evidence. Its objective is to provide the standard perspective for the management of potential organ/tissue donors after brain death (BD) in adults only, regardless of the availability of technology. This document should only be used for guidance only and is not a substitute for proper clinical decision making in particular circumstances of any case. Endorsement by the ISCCM does not imply that the statements given in the document are applicable in all or in a particular case; however, they may provide guidance for the users thus facilitating maximum organ availability from brain-dead patients. Thus, the care of potential brain-dead organ donors is "caring for multiple recipients."

How to cite this article

Zirpe K, Pandit R, Gurav S, Mani RK, Prabhakar H, Clerk A, et al. Management of Potential Organ Donor: Indian Society of Critical Care Medicine-Position Statement. Indian J Crit Care Med 2024;28(S2):S249-278.

An Update on Brain Death/Death by Neurologic Criteria since the World Brain Death Project

The World Brain Death Project (WBDP) is a 2020 international consensus statement that provides historical background and recommendations on brain death/death by neurologic criteria (BD/DNC) determination. It addresses 13 topics including: (1) worldwide variance in BD/DNC, (2) the science of BD/DNC, (3) the concept of BD/DNC, (4) minimum clinical criteria for BD/DNC determination, (5) beyond minimum clinical BD/DNC determination, (6) pediatric and neonatal BD/DNC determination, (7) BD/DNC determination in patients on ECMO, (8) BD/DNC determination after treatment with targeted temperature management, (9) BD/DNC documentation, (10) qualification for and education on BD/DNC determination, (11) somatic support after BD/DNC for organ donation and other special circumstances, (12) religion and BD/DNC: managing requests to forego a BD/DNC evaluation or continue somatic support after BD/DNC, and (13) BD/DNC and the law. This review summarizes the WBDP content on each of these topics and highlights relevant work published from 2020 to 2023, including both the 192 citing publications and other publications on BD/DNC. Finally, it reviews questions for future research related to BD/DNC and emphasizes the need for national efforts to ensure the minimum standards for BD/DNC determination described in the WBDP are included in national BD/DNC guidelines and due consideration is given to the recommendations about social and legal aspects of BD/DNC determination.

Apnea Testing Practice to Increase Baseline PaCO2 and Frequency of Blood Gas Analyses

OBJECTIVE

To study the influence of the initial partial pressure of carbon dioxide (PaCO2) and frequency of blood gas analyses on the positivity rate and safety of apnea testing (AT).

DESIGN

A prospective multicenter cohort study.

SETTING

Seven teaching hospitals.

PARTICIPANTS

A total of 55 patients who underwent AT.

INTERVENTIONS

Patients were divided into 2 groups according to their initial PaCO2-the experimental group (≥40 mmHg, 27 patients) and the control group (<40 mmHg, 28 patients). Blood gas analysis was performed at 3, 5, and 8 minutes, and vital signs were taken. AT results and complications were compared between the groups.

RESULTS

The initial PaCO2 of the experimental group was 42.8 ± 2.2 mmHg v 36.4 ± 2.9 mmHg in the controls. The AT positivity rate was 100%. The experimental group needed less time to reach the target PaCO2 than the control group (4.07 ± 1.27 minutes v 5.68 ± 2.06 minutes; p = 0.001). Twenty-six patients (96.3%) in the experimental group reached the target PaCO2 in 5 minutes v 17 in the control group (60.7%) (p = 0.001). Seven patients (12.7%) were unable to complete 8-minute disconnection due to hypotension. The experimental group had a slightly lower incidence of hypotension than the control group, but there was no statistical difference (7.4% v 17.9%, p = 0.245).

CONCLUSION

Increasing the baseline PaCO2 and doing more blood gas analyses can significantly shorten the time needed for AT and improve the AT positivity rate.

The 2023 American Academy of Neurology, American Academy of Pediatrics, Child Neurology Society, and Society of Critical Care Medicine Pediatric and Adult Brain Death/Death by Neurologic Criteria Determination Consensus Guidelines: What the Critical Care Team Needs to Know

Guidelines for brain death/death by neurologic criteria (BD/DNC) determination were revised to provide a consistent and updated approach to BD/DNC evaluation across all ages by the American Academy of Neurology, American Academy of Pediatrics, Child Neurology Society, and Society of Critical Care Medicine. This article is intended to complement the guidelines and highlight aspects relevant to the critical care community; the actual guidelines should be used to update hospital protocols and dictate clinical practice. Because BD/DNC evaluations are conducted in the ICU, it is essential for members of the critical care community to familiarize themselves with these guidelines. The fundamental concept of BD/DNC has not changed; BD/DNC is permanent loss of function of the brain as a whole, including the brain stem, resulting in coma, brainstem areflexia, and apnea in the setting of an adequate stimulus. The BD/DNC evaluation requires a sufficient observation period to ensure there is no chance of recovery, followed by exclusion of potentially confounding conditions like hypothermia, hypotension, severe metabolic disturbances, or medication effects. Specific guidance is provided for patients who were treated with therapeutic hypothermia or medical or surgical interventions to manage intracranial hypertension. The guidelines outline a structured and meticulous neurologic examination and detail the responses consistent with BD/DNC. A protocol is provided for how to safely perform apnea testing, including modifications needed for patients on extracorporeal membrane oxygenation. Controversial issues such as consent, BD/DNC evaluation in pregnancy, preservation of neuroendocrine function, and primary posterior fossa injuries are addressed. The ultimate goal is to ensure a consistent and accurate approach to BD/DNC evaluation in patients of all ages, fostering public trust in the medical community's ability to determine death. By adhering to these guidelines, critical care clinicians can confidently navigate the challenging aspects of BD/DNC determination.

Improvement Gaps to Deal with the Shortage of Lungs for Transplant From a Middle Income Country's Perspective

OBJECTIVES

Our study aimed to identify the potential causes for the low lung procurement rate in Argentina and to develop strategies to the actual problems in donor management focused on lung retrieval.

MATERIALS AND METHODS

We performed a crosssectional study in which we analyzed data obtained from digital self-reported surveys conducted on professionals participating in the organ procurement process in Argentina. The surveys included questions on donor management, selection criteria, and resource availability involving increasing lung procurement.

RESULTS

Among professionals surveyed, 23.7% did not use advanced hemodynamic monitoring in their donor maintenance and limited their use to central venous pressure. Only 35.8% of participants considered maintaining central venous pressure <10 mm Hg during donor maintenance. With regard to donors with severe deterioration of the ejection fraction, 47.4% of participants would not use restrictive fluid, and only 23.2% would use an advanced monitoring of the hemodynamic status to guide fluid management. Only 27.8% of participants routinely would use steroids to improve lung function in donors. With regard to mechanical ventilation, 80.4% of participants used protective ventilation, but only 4.10% used it adequately. Recruitment maneuvers were routinely used by only 3.1% of those surveyed. With regard to expanded selection criteria (age >55 years, smoking habit of >20 packs/year, positive upper airway cultures, unspecific infiltrates in radiography, and >72 hours of mechanical ventilation), 92.8% of surveyed participants would discount patients with some of these expanded selection criteria without considering offering the lungs for donation.

CONCLUSIONS

Opportunities for improvement may involve training physicians involved in the donor maintenance process and reviewing the donor selection criteria used to increase adherence to expanded selection criteria.

Pediatric and Adult Brain Death/Death by Neurologic Criteria Consensus Guideline

BACKGROUND AND OBJECTIVES

The purpose of this guideline is to update the 2010 American Academy of Neurology (AAN) brain death/death by neurologic criteria (BD/DNC) guideline for adults and the 2011 American Academy of Pediatrics, Child Neurology Society, and Society of Critical Care Medicine guideline for infants and children and to clarify the BD/DNC determination process by integrating guidance for adults and children into a single guideline. Updates in this guideline include guidance related to conducting the BD/DNC evaluation in the context of extracorporeal membrane oxygenation, targeted temperature management, and primary infratentorial injury.

METHODS

A panel of experts from multiple medical societies developed BD/DNC recommendations. Because of the lack of high-quality evidence on the subject, a novel, evidence-informed formal consensus process was used. This process relied on the panel experts' review and detailed knowledge of the literature surrounding BD/DNC to guide the development of preliminary recommendations. Recommendations were formulated and voted on, using a modified Delphi process, according to the 2017 AAN Clinical Practice Guideline Process Manual.

MAJOR RECOMMENDATIONS

Eighty-five recommendations were developed on the following: (1) general principles for the BD/DNC evaluation, (2) qualifications to perform BD/DNC evaluations, (3) prerequisites for BD/DNC determination, (4) components of the BD/DNC neurologic examination, (5) apnea testing as part of the BD/DNC evaluation, (6) ancillary testing as part of the BD/DNC evaluation, and (7) special considerations for BD/DNC determination.

Consent for determination of death by neurologic criteria in Canada: an analysis of legal and ethical authorities, and consensus-based working group recommendations

This article addresses the following question: should physicians obtain consent from the patient (through an advance directive) or their surrogate decision-maker to perform the assessments, evaluations, or tests necessary to determine whether death has occurred according to neurologic criteria? While legal bodies have not yet provided a definitive answer, significant legal and ethical authority holds that clinicians are not required to obtain family consent before making a death determination by neurologic criteria. There is a near consensus among available professional guidelines, statutes, and court decisions. Moreover, prevailing practice does not require consent to test for brain death. While arguments for requiring consent have some validity, proponents cannot surmount weightier considerations against imposing a consent requirement. Nevertheless, even though clinicians and hospitals may not be legally required to obtain consent, they should still notify families about their intent to determine death by neurologic criteria and offer temporary reasonable accommodations when feasible. This article was developed with the legal/ethics working group of the project, A Brain-Based Definition of Death and Criteria for its Determination After Arrest of Circulation or Neurologic Function in Canada developed in collaboration with the Canadian Critical Care Society, Canadian Blood Services, and the Canadian Medical Association. The article is meant to provide support and context for this project and is not intended to specifically advise physicians on legal risk, which in any event is likely jurisdiction dependent because of provincial or territorial variation in the laws. The article first reviews and analyzes ethical and legal authorities. It then offers consensus-based recommendations regarding consent for determination of death by neurologic criteria in Canada.

Quality improvement in the determination of death by neurologic criteria around the world

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2023. Other selected articles can be found online at https://www.biomedcentral.com/collections/annualupdate2023 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from https://link.springer.com/bookseries/8901 .

Optimal duration of the apnea test for determining brain death: Benefit of the short-term apnea test

Background

The criteria for brain death determination have not been unified globally, and there is no global consensus on the apnea test, which is essential for determining brain death. Since the apnea test is associated with many complications, we aimed to determine an optimal duration of the apnea test.

Methods

We analyzed the results of the apnea test performed for brain death determination between August 2013 and February 2021 at a single institution in South Korea. Elevations in the partial pressure of carbon dioxide and mean arterial blood pressure fluctuations over time in the apnea test were recorded.

Results

In the 1^st and 2^nd tests, the mean partial pressure of carbon dioxide increased by more than 20 mmHg at 3 min after the apnea test compared to before the test (P < 0.05). At 4 min in the 1^st test and 5 min in the 2^nd test, the partial pressure of carbon dioxide exceeded 60 mmHg (P < 0.05). The fluctuation in the mean arterial blood pressure observed for 5 min during the apnea test was not significant. There was no significant fluctuation in the mean arterial blood pressure over time in the apnea test between patients with normal chest radiography findings and those with abnormal chest radiography findings (P = 0.888).

Conclusions

Our study proposes that a short-term apnea test protocol is valid for the preservation of organs for donation.

The practical role of the respiratory therapist in the standard apnea test procedure for declaration of death via neurologic criteria in adults

Introduction

Respiratory therapists (RTs) in the intensive care unit can at times find themselves involved in and assisting during the performance of the apnea test (ApT). The ApT is a clinically complex procedure and is the last part of the clinical declaration of death by neurologic criteria (DNC) protocol and requires close collaboration between the physicians and the RTs. As such, the ApT should be performed with the upmost attention to detail.

Context and Aims

The RTs need to be versed on the intricacies of the ApT. Except in very large medical centers, the ApT is not a procedure performed with high enough frequency as to maintain high level of proficiency. For a successful ApT, structured knowledge and preparation are paramount. This publication attempts to fill that gap, for adult hospitalized patients not on ECMO (extracorporeal membrane oxygenation). To generate this report, we make use of the published guidelines, and our personal experience on performing ApTs in large medical centers.

Conclusion

We provide a structure by means of a checklist, from the RTs’ perspective, to guide and help them lead on the efficient performance of the ApT.

Minimum Criteria for Brain Death Determination: Consensus Promotion and Chinese Practice

BACKGROUND

Brain death (BD), the irreversible cessation of function in the whole brain, is a well-known condition in most countries. The criteria and practical guidelines for brain death determination (BDD) in China were issued by the Brain Injury Evaluation Quality Control Center (BQCC) of the National Health and Family Planning Commission in 2013. Thereafter, we proposed a plan called the three-step quality control plan (three-step QCP) to ensure the safety and consistency of the clinical judgments regarding BD. By retrospectively reviewing this plan, we aimed to identify problems during its implementation and to provide suggestions for future work on quality control for BDD.

METHODS

Data were retrieved from the BQCC database. The characteristics and test results of physicians undergoing a BDD training course and the BD case records submitted by hospitals before and after receiving accreditation were analyzed.

RESULTS

In the first step of the plan, the error rate for physicians undergoing the BDD paper test was highest for limb movement discrimination (26.29%); this error rate was correlated with age (per 10-year increase) (odds ratio = 1.262, 95% confidence interval 1.067-1.491, P = 0.007) but was nonsignificantly associated with sex, specialty category, professional level, and hospital level (P > 0.05). During the second step of the plan, the highest percentage of problems was associated with apnea testing (22.75%), followed by ancillary testing of BDD (16.17%). In the last step, the highest percentage of problems in the case records was associated with apnea testing (41.73%).

CONCLUSIONS

The three-step QCP is of significant utility for ensuring accuracy and appropriateness in BDD. Simultaneously, this study provides important evidence for advancing quality control for BDD in the next stage.

Safety and reliability of artificial CO2 augmentation method in comparison with standard apneic oxygenation method for brain death determination

INTRODUCTION

The most commonly used apnea test for determination of brain death is the apneic oxygenation method. While all the commonly used apnea tests have associated complications, artificial CO2 augmentation has been reported to have fewer complications. However, data supporting the use of the latter method is limited.

METHODS

We identified 102 patients who underwent brain death testing during the last ten years. Artificial CO2 augmentation apnea testing was used in 50 of these patients while 52 patients underwent standard apneic oxygenation apnea testing.

RESULTS

No significant differences between the two groups were noted in any previously considered clinical outcomes, including hypoxemia, acidemia, or shock. However, shorter duration of apnea testing was observed in the artificial CO2 augmentation method suggesting its feasibility to the standard apneic oxygenation method in terms of convenience and reduction of the risk surrounding prolonged hypercapnia and hypoxemia.

CONCLUSION

This retrospective cohort study provides further observational evidence to support the safety of alternate apnea testing techniques with the standard apnea method for determination of brain death in adults.

Apnea Test on Extracorporeal Membrane Oxygenation: Step Forward with Carbon Dioxide

Apnea test must be performed to confirm brain death in patients meet clinical criteria. But the increment of carbon dioxide is generally not achievable because of the diminished production of carbon dioxide and additional sweep in extra corporeal membrane oxygenation (ECMO). We report three children with congenital heart disease treated with ECMO and had brain death during follow-up. All met clinical criteria but apnea test cannot be achieved in classical way because of prolonged duration and hemodynamic compromise. Therefore, we used external carbon dioxide to achieve desired levels of oxygen and carbon dioxide safely. Because of the lack of protocols for pediatric patients on ECMO, apnea test with exogenous carbon dioxide may be a reliable and rapid test in such patients. Especially cardiac patients, in whom classical apnea test can cause rapid deterioration, exogenous carbon dioxide may serve as an alternative.

Bilateral Pneumothoraces in a 3-Month-Old Infant During an Apnea Test in the Diagnosis of Brain Death

We present the case of a 3-month-old boy who suffered bilateral pneumothoraces secondary to insufflation of oxygen into the endotracheal tube during the apnea test as part of brain death testing. Although rare, awareness of this potential complication of the apnea test is of particular importance in pediatric patients who have narrow endotracheal tubes because resistance to expiratory flow increases exponentially as lumen diameter decreases.