Variability in deceased donor care in Canada: a report of the Canada-DONATE cohort study

Critical care specialists, the missing link in organ procurement for transplantation

The procurement process for organ donation begins with the identification of potential organ donors in emergency or critical care units (CCU), followed by their clinical evaluation, diagnostic procedures, and therapeutic interventions, mostly conducted in CCUs. It concludes with the request for organ donation and, if accepted, the retrieval of organs. Despite most interventions occurring in detection units, there has been a neglect of the strategic role played by critical care specialists (CCS) in managing and caring for brain-dead or near-brain-death patients. Questions arise: Are they willing to undertake this responsibility? Do they fully comprehend the nature of organ procurement? Are they aware of the specific interventions required to maintain possible organ donors in optimal physiological condition? Our objective is to examine the role of CCS in organ procurement and propose ways to enhance it, ultimately aiming to increase and enhance organ donation rates.

Calcineurin Inhibition in Deceased Organ Donors: A Systematic Review and Meta-analysis of Preclinical Studies

Background

Preconditioning deceased organ donors with calcineurin inhibitors (CNIs) may reduce ischemia-reperfusion injury to improve transplant outcomes.

Methods

We searched MEDLINE, EMBASE, Cochrane Library, and conference proceedings for animal models of organ donation and transplantation, comparing donor treatment with CNIs with either placebo or no intervention, and evaluating outcomes for organ transplantation. Reviewers independently screened and selected studies, abstracted data, and assessed the risk of bias and clinical relevance of included studies. Where possible, we pooled results using meta-analysis; otherwise, we summarized findings descriptively.

Results

Eighteen studies used various animals and a range of CNI agents and doses and evaluated their effects on a variety of transplant outcomes. The risk of bias and clinical applicability were poorly reported. Pooled analyses suggested benefit of CNI treatment on early graft function in renal transplants (3 studies; serum creatinine: ratio of means [RoM] 0.54; 95% confidence interval [CI], 0.34-0.86) but not for liver transplants (2 studies; serum alanine transaminase: RoM 0.61; 95% CI, 0.30-1.26; and serum aspartate aminotransferase: RoM 0.58; 95% CI, 0.26-1.31). We found no reduction in graft loss at 7 d (2 studies; risk ratio 0.54; 95% CI, 0.08-3.42). CNI treatment was associated with reduced transplant recipient levels of interleukin-6 (4 studies; RoM 0.36; 95% CI, 0.19-0.70), tumor necrosis factor-alpha (5 studies; RoM 0.36; 95% CI, 0.12-1.03), and cellular apoptosis (4 studies; RoM 0.30; 95% CI, 0.19-0.47).

Conclusions

Although this compendium of animal experiments suggests that donor preconditioning with CNIs may improve early kidney graft function, the limited ability to reproduce a true clinical environment in animal experiments and to assess for risk of bias in these experiments is a serious weakness that precludes current clinical application.

Comment on Oehler et al. Outcome and Midterm Survival after Heart Transplantation Is Independent from Donor Length of Stay in the Intensive Care Unit. Life 2022, 12, 1053

Oehler et al. described an interesting finding, stating that length of stay (LOS) of the donors in the intensive care unit (ICU) did not have an impact on the outcomes and survival of recipients up to 5 years after heart transplantation (HTx) [...].

Reply to Thet et al. Comment on "Oehler et al. Outcome and Midterm Survival after Heart Transplantation Is Independent from Donor Length of Stay in the Intensive Care Unit. Life 2022, 12, 1053"

Myat Soe Thet et al. published a letter [...].

Program of Uncontrolled Donation After Circulatory Death as Potential Solution to the Shortage of Organs: A Canadian Single-Center Retrospective Cohort Study

Purpose

Worldwide, the number of patients waiting for organ transplantation exceeds the number of organs available. Program for uncontrolled donation after circulatory death (uDCD) implemented in Europe has resulted in a 10–15% expansion of the donor pool. We aimed to describe the number of patients eligible for an uDCD program in a regional tertiary care center.

Methods

We conducted a retrospective cohort study in a Canadian tertiary academic center located in a rural area including all adults who received cardiopulmonary resuscitation in 2016 and died in the emergency department (ED) or during their hospitalization. The primary outcome was the number of patients eligible for uDCD defined as aged between 18 and 60 years old whose collapse was witnessed and where the time between cardiac arrest to cardiopulmonary resuscitation and ED arrival was, respectively, less than 30 and 120 minutes. As a secondary outcome, we determined the number of patients eligible for controlled donation after circulatory death.

Results

Of the 130 patients included, 84 did not return to spontaneous circulation. We identified 15 potential uDCD candidates, with a mean age of 46.6 (95% Confidence Interval [CI] 41.3 to 52) years. Twelve had an out-of-hospital cardiac arrest with a mean time between collapse and arrival to the ED of 43.2 (29.8 to 56.6) minutes. Among the 46 patients who died after a return of spontaneous circulation, 10 (21.7%) were eligible for organ donation after circulatory death.

Conclusion

Implementing an uDCD program in a tertiary hospital covering a rural area could increase the number of donors.

Outcome and Midterm Survival after Heart Transplantation Is Independent from Donor Length of Stay in the Intensive Care Unit

Prolonged treatment of organ donors in the intensive care unit (ICU) may be associated with complications influencing the outcome after heart transplantation (HTx). We therefore aim to explore the potential impact of the donor length of stay (LOS) in the ICU on outcomes in our cohort. We included all patients undergoing HTx in our center between September 2010 and April 2022 (n = 241). Recipients were divided around the median into three groups regarding their donor LOS in the ICU: 0 to 3 days (≤50th percentile, n = 92), 4 to 7 days (50th–75th percentile, n = 80), and ≥8 days (≥75th percentile, n = 69). Donor LOS in the ICU ranged between 0 and 155 days (median 4, IQR 3–8 days). No association between the LOS in the ICU and survival after HTx was observed (AUC for overall survival 0.514). Neither the Kaplan–Meier survival analysis up to 5 years after HTx (Log-Rank p = 0.789) nor group comparisons showed significant differences. Baseline recipient characteristics were comparable between the groups, while the donor baselines differed in some parameters, such as less cardiopulmonary resuscitation prior to HTx in those with a prolonged LOS. However, regarding the recipients’ peri- and postoperative parameters, the groups did not differ in all of the assessed parameters. Thus, in this retrospective analysis, although the donors differed in baseline parameters, the donor LOS in the ICU was not associated with altered recipient survival or outcome after HTx.

Antemortem Heparin in Organ Donation After Circulatory Death Determination: A Systematic Review of the Literature

Donation after circulatory death determination frequently involves antemortem heparin administration to mitigate peri-arrest microvascular thrombosis. We systematically reviewed the literature to: (1) describe heparin administration practices and (2) explore the effects on transplant outcomes. We searched MEDLINE and EMBASE for studies reporting donation after circulatory death determination heparin practices including use, dosage, and timing (objective 1). To explore associations between antemortem heparin and transplant outcomes (objective 2), we (1) summarized within-study comparisons and (2) used meta-regression analyses to examine associations between proportions of donors that received heparin and transplant outcomes. We assessed risk of bias using the Newcastle Ottawa Scale and applied the GRADE methodology to determine certainty in the evidence. For objective 1, among 55 eligible studies, 48 reported heparin administration to at least some donors (range: 15.8%-100%) at variable doses (up to 1000 units/kg) and times relative to withdrawal of life-sustaining therapy. For objective 2, 7 studies that directly compared liver transplants with and without antemortem heparin reported lower rates of primary nonfunction, hepatic artery thrombosis, graft failure at 5 y, or recipient mortality (low certainty of evidence). In contrast, meta-regression analysis of 32 liver transplant studies detected no associations between the proportion of donors that received heparin and rates of early allograft dysfunction, primary nonfunction, hepatic artery thrombosis, biliary ischemia, graft failure, retransplantation, or patient survival (very low certainty of evidence). In conclusion, antemortem heparin practices vary substantially with an uncertain effect on transplant outcomes. Given the controversies surrounding antemortem heparin, clinical trials may be warranted.

Ethical considerations in the use of pre-mortem interventions to support deceased organ donation: A scoping review

AIM

Pre-mortem interventions (PMIs) are performed on patients before the determination of death in order to preserve or enhance the possibility of organ donation. These interventions can be ethically controversial, and we thus undertook a scoping review of the ethical issues surrounding diverse PMIs.

METHODS

Using modified scoping review methods, we executed a search strategy created by an information specialist. Screening and iterative coding of each article was done by two researchers using qualitative thematic analysis, and narrative summaries of coded themes were presented.

RESULTS

We identified and screened 5365 references and coded 196 peer-reviewed publications. The most frequently cited issues were related to possible harms to the patient who is a potential donor, and legitimacy of consent. The most controversial issue was that PMIs may place patients at risk for physical harm, yet benefit is accrued mainly to recipients. Some authors argued that lack of direct medical benefit to the still living patient precluded valid consent from surrogate decision makers (SDMs), while many stated that some medical risk could be approved by SDMs if it aligns with non-medical benefits valued by the patient.

CONCLUSION

PMIs require consensus that benefit includes concepts beyond medical benefit to the patient who is a potential donor. Informed consent must be confirmed for each PMI and not assumed to be part of general consent for donation. Risk must be proportionate to the potential benefit and newly proposed interventions should be reviewed carefully for medical efficacy and potential risks.

Worldwide management of donors after neurological death: a systematic review and narrative synthesis of guidelines

OBJECTIVE

The objectives of this study were to systematically identify and describe guidelines for the care of neurologically deceased donors and to evaluate their methodological quality, with the aim of informing and supporting the new Canadian guidelines for the management of organ donors.

METHODOLOGY

Following a systematic search, we included any document endorsed by an organ donation organization, a professional society, or a government, that aims to direct the medical management of adult, neurologically deceased, multi-organ donors. We extracted recommendations pertaining to six domains: the autonomic storm, hemodynamic instability, hormone supplementation, ventilation, blood product transfusions, and general intensive care unit (ICU) care. Methodological quality of the guidelines was assessed by the validated AGREE-II tool.

MAIN FINDINGS

This review includes 27 clinical practice guidelines representing 26 countries published between 1993 and 2019. Using the AGREE-II validated tool for the evaluation of guidelines' quality, documents generally scored well on their scope and clarity of presentation. Nevertheless, quality was limited in terms of the scientific rigor of guideline development. Recommendations varied substantially across the domains of managing the autonomic storm, subsequent management of hemodynamic instability, hormone therapy, mechanical ventilation, blood product transfusion, and general ICU care. We found consistent recommendations for low tidal volume ventilation subsequent to the publication of a landmark clinical trial.

CONCLUSION

Highly inconsistent recommendations for deceased donor care summarized in this review likely reflect the relatively slow emergence of high-quality clinical research in this field, as well as a late uptake of recent validated guideline methodology. Even in this context of few randomized-controlled trials, our group supported the need for new Canadian guidelines for the management of organ donors that follow rigorous recognized methodology and grading of the evidence.

TRIAL REGISTRATION

PROSPERO (CRD42018084012); registered 25 February 2016.