Transplantation of kidneys from a donor with carbon monoxide poisoning

Application of carbon monoxide in kidney and heart transplantation: A novel pharmacological strategy for a broader use of suboptimal renal and cardiac grafts

Carbon monoxide (CO) was historically regarded solely as a poisonous gas that binds to hemoglobin and reduces oxygen-carrying capacity of blood at high concentrations. However, recent findings show that it is endogenously produced in mammalian cells as a by-product of heme degradation by heme oxygenase, and has received a significant attention as a medical gas that influences a myriad of physiological and pathological processes. At low physiological concentrations, CO exhibits several therapeutic properties including antioxidant, anti-inflammatory, anti-apoptotic, anti-fibrotic, anti-thrombotic, anti-proliferative and vasodilatory properties, making it a candidate molecule that could protect organs in various pathological conditions including cold ischemia-reperfusion injury (IRI) in kidney and heart transplantation. Cold IRI is a well-recognized and complicated cascade of interconnected pathological pathways that poses a significant barrier to successful outcomes after kidney and heart transplantation. A substantial body of preclinical evidence demonstrates that CO gas and CO-releasing molecules (CO-RMs) prevent cold IRI in renal and cardiac grafts through several molecular and cellular mechanisms. In this review, we discuss recent advances in research involving the use of CO as a novel pharmacological strategy to attenuate cold IRI in preclinical models of kidney and heart transplantation through its administration to the organ donor prior to organ procurement or delivery into organ preservation solution during cold storage and to the organ recipient during reperfusion and after transplantation. We also discuss the underlying molecular mechanisms of cyto- and organ protection by CO during transplantation, and suggest its clinical use in the near future to improve long-term transplantation outcomes.

Carbon monoxide as an emerging pharmacological tool to improve lung and liver transplantation protocols

Carbon monoxide (CO) has long been considered purely as a toxic gas. It binds to hemoglobin at high concentrations and displaces oxygen from its binding site, resulting in carboxyhemoglobin formation, which reduces oxygen-carrying capacity of blood and culminates in tissue hypoxia and its associated complications. Recently, however, CO is quickly moving past its historic notorious tag as a poisonous gas to a physiological signaling molecule with therapeutic potentials in several clinical situations including transplant-induced injury. This review discusses current knowledge of CO gas and CO-releasing molecules (CO-RMs) in preclinical models of lung and liver transplantation, and underlying molecular mechanisms of cyto- and organ protection during organ procurement, preservation, implantation and post-transplant periods. In addition, a discussion of the future of CO in clinical organ transplantation is provided.

Carbon monoxide: An emerging therapy for acute kidney injury

Treating acute kidney injury (AKI) represents an important unmet medical need both in terms of the seriousness of this medical problem and the number of patients. There is also a large untapped market opportunity in treating AKI. Over the years, there has been much effort in search of therapeutics with minimal success. However, over the same time period, new understanding of the underlying pathobiology and molecular mechanisms of kidney injury have undoubtedly helped the search for new therapeutics. Along this line, carbon monoxide (CO) has emerged as a promising therapeutic agent because of its demonstrated cytoprotective, and immunomodulatory effects. CO has also been shown to sensitize cancer, but not normal cells, to chemotherapy. This is particularly important in treating cisplatin-induced AKI, a common clinical problem that develops in patients receiving cisplatin therapies for a number of different solid organ malignancies. This review will examine and make the case that CO be developed into a therapeutic agent against AKI.

Successful Renal Transplantation after Presumed Cyanide Toxicity Treated with Hydroxocobalamin and Review of the Literature

We report two cases of successful renal transplantation with allografts from donors who suffered anoxic brain injury as the primary cause of death from house fires. Each was treated prophylactically with hydroxocobalamin (Cyanokit) for suspected cyanide toxicity. During organ procurement, gross examination was notable for deep discoloration of the parenchymal tissues. Approximately 6 and 18 months after transplantation, both recipients have excellent renal graft function and remain independent from hemodialysis (HD). Hydroxocobalamin is the antidote for suspected acute cyanide toxicity. While largely tolerated by the recipient, there is concern over the potential functional implications of the associated side effects of dramatic tissue discoloration and development of oxalate crystals. Furthermore, difficulties performing hemodialysis in patients treated with hydroxocobalamin have been reported due to discoloration of the effluent fluid impacting the colorimetric sensor, causing false alarms and repetitive interruptions. As such, many transplant centers in the United States (US) continue to reject these organs. We seek to highlight two cases of successful transplantation following donor administration of hydroxocobalamin (Cyanokit) and present the first documented case of successful perioperative intermittent hemodialysis following transplantation of an allograft exposed to hydroxocobalamin. Furthermore, we emphasize the importance of optimal organ utilization and caution against unnecessary refusal.

Organ Donor Issues for the Intensive Care Physician

The opportunity for organ donation most often arises in the intensive care unit following the declaration of brain death. Thus a comprehensive discussion of the topic of organ donation is of special importance to the intensive care physician. The essential criteria of brain death are provided in this review; however, a unitarian concept is emphasized, that all death is occasioned by an irreversible loss of brain function. Recovery of organs from a non-heart-beating organ donor is presented in this context. The characteristics of the suitable cadaver organ donor are reviewed, detailing donor age considerations and the exclusion criteria of HIV infection and a history of donor malignancy. An analysis of death caused by specific poisons is presented that is amenable to cadaver organ donation. The shortage of cadaver organs for transplantation persists. The major obstacle to donation is family consent. A paradigm of procedure from organ donor referral to organ recovery in the operating room is outlined, with a discussion of the suggested best practice for achieving family consent. This emphasizes the need for highly trained personnel to request consent for organ donation. Intensive care unit management of the donor following the declaration of death is given by a problem-oriented review, intended to preserve hemodynamic stability until organ recovery can be accomplished.

Can carbon monoxide-poisoned victims be organ donors?

The increasing demand for organ allografts to treat end-stage organ failure has driven changes in traditional donor criteria. Patients who have succumbed to carbon monoxide (CO) poisoning, a common cause of toxicological mortality, are usually rejected as organ donors. To fulfill the increasing demand, selection criteria must be expanded to include CO-poisoned donors. However, the use of allografts exposed to high CO concentrations is still under debate. Basic research and literature review data suggest that patients with brain death caused by CO poisoning should be considered appropriate organ donors. Accepting organs from CO-poisoned victims could increase the number of potential donors and lower the death rate of patients on the waiting lists. This review and reported cases may increase awareness among emergency department physicians, as well as transplant teams, that patients dying of CO exposure may be acceptable organ donors.

Use of carbon monoxide in minimizing ischemia/reperfusion injury in transplantation

Although carbon monoxide (CO) is known to be toxic because of its ability to interfere with oxygen delivery at high concentrations, mammalian cells endogenously generate CO primarily via the catalysis of heme by heme oxygenases. Recent findings have indicated that heme oxygenases and generation of CO serve as a key mechanism to maintain the integrity of the physiological function of organs and supported the development of a new paradigm that CO, at low concentrations, functions as a signaling molecule in the body and exerts significant cytoprotection. Consequently, exogenously delivered CO has been shown to mediate potent protection in various injury models through its anti-inflammatory, vasodilating, and antiapoptotic functions. Ischemia/reperfusion (I/R) injury associated with organ transplantation is one of the major deleterious factors limiting the success of transplantation. Ischemia/reperfusion injury is a complex cascade of interconnected events involving cell damage, apoptosis, vigorous inflammatory responses, microcirculation disturbance, and thrombogenesis. Carbon monoxide has a great potential in minimizing I/R injury. This review will provide an overview of the basic physiology of CO, preclinical studies examining efficacy of CO in I/R injury models, and possible protective mechanisms. Carbon monoxide could be developed to be a valuable therapeutic molecule in minimizing I/R injury in transplantation.

Solid organ procurement from donors with carbon monoxide poisoning and/or burn--a systematic review

INTRODUCTION

Traditionally, carbon monoxide poisoning and/or burn are considered contraindications to organ procurement. Previously reported cases have shown mixed results and many have been redundantly reported in the literature.

METHODS

We performed a systematic review of all reported cases of organ transplantation procured from donors with carbon monoxide poisoning and/or burn to investigate whether these patients are suitable donors for solid organ transplantations.

RESULTS

Organ survival rates of reported organs were high (86%). All organs procured from donors with carbon monoxide poisoning and burn survived during follow-up. Mean donors' peak carbon monoxide levels were comparable for organs surviving or failing during follow-up (31 ± 2.7 vs. 29 ± 26.8; p=0.95). Eighty-seven per cent of organs procured from donors supported with inotropes or vasopressors prior to organ procurement and 91% of organs procured from donors who were cardiopulmonary resuscitated prior to organ procurement survived during follow-up.

CONCLUSIONS

Burn, carbon monoxide poisoning, high peak carbon monoxide-levels, use of inotropes or vasopressors or cardiopulmonary resuscitation prior to procurement are not contraindications for organ procurement and transplantation. New guidelines for burn units defining the special requirements for organ procurement from donors with carbon monoxide poisoning and/or burn are needed to raise the awareness for potential organ donors and to ultimately increase the donor pool and save patients' lives.

Poisoned patients as potential organ donors: postal survey of transplant centres and intensive care units

BACKGROUND

The number of patients awaiting allograft transplantation in the UK exceeds the number of organs offered for transplantation each year. Most organ donors tend to be young, fit and healthy individuals who die because of trauma or sudden cardiac arrest. Patients who die from drug and poison intoxication tend to have similar characteristics but are less frequently offered as potential organ donors.

METHODS

A postal questionnaire survey of all transplantation centres and an equal number of intensive care units in the UK was undertaken. The use of kidney, heart, lung, liver and pancreas transplants from poisoned patients following deliberate methanol ingestion, cardiac arrest presumed secondary to cocaine overdose, accidental domestic carbon monoxide inhalation and industrial cyanide exposure were used as case scenarios.

RESULTS

Response rates were 70% for transplantation centres and 50% for intensive care unit directors. Over 80% of organs would be offered or discussed with transplant coordinators by intensive care unit directors. Transplantation physicians/surgeons would consider transplanting organs in up to 100% of case scenarios, depending on the organ and poisoning or intoxication involved.

DISCUSSION

The postal survey presented here shows that most transplantation physicians and surgeons and intensive care unit directors would consider those who die following acute drug intoxication and poisoning as potential organ donors. The previously reported literature shows in general that transplanted organs from poisoned patients have good long-term survival, although the number of reports is small. Poisoned patients are another pool of organ donors who at present are probably underused by transplantation services.

Part 8: advanced challenges in resuscitation. Section 2: toxicology in ECC

Use of standard ACLS protocols for all patients who are critically poisoned may not result in an optimal outcome. Care of severely poisoned patients can be enhanced by urgent consultation with a medical toxicologist. Alternative approaches required in severely poisoned patients include: o Higher doses than usual. o Drugs that are rarely used to treat cardiac arrest (amrinone, calcium, esmolol, glucagon, insulin, labetalol, phenylephrine, physostigmine, and sodium bicarbonate). o Heroic measures, such as prolonged CPR and use of circulatory assist devices. When resuscitation is unsuccessful, organ donation may still be an option.

Successful heart transplantation from a victim of carbon monoxide poisoning

Heart transplantation has become a highly successful, life-saving treatment for a number of otherwise fatal heart diseases. A major limiting factor in the growth of transplantation surgery has been the relative lack of suitable donor organs, and the appropriate criteria for selection of donor organs have been a topic of significant interest. Despite relatively favorable survival rates in the few patients who have received organs from victims of many types of poisonings and drug overdoses, patients dying of toxicologic causes are not usually considered suitable organ donors. Some centers routinely reject such individuals. Criteria for donor selection continue to be vague, unclear, or nonexistent in regard to organ transplantation from victims of all types of poisoning and toxic exposures. Carbon monoxide (CO) is a ubiquitous poison, and although victims of CO poisoning have occasionally served as suitable organ donors, heart transplantation in this scenario is still a very rare event. We describe the successful transplantation of the heart from a CO poisoning victim--to our knowledge, only the third such transplantation. Because the emergency department is a critical site for organ procurement, emergency physicians must be aware that patients dying of CO exposure may be acceptable organ donors.

The toxic patient as a potential organ donor

The use of organs from poisoned victims for the purpose of transplantation has been poorly studied; criteria for organ donation is virtually non-existent in such cases. To further elucidate these indications, a retrospective review of all organ transplantation donated by poisoned victims in Northern and Central Illinois was undertaken. From January 1988 to December 1993, 17 poisoned victims were identified as having donated organs to 41 recipients. Eleven of the donors died as a direct result of drug toxicity, whereas six donors had drug-related deaths. The cases were reviewed for toxin involved, organ preoperative function and postoperative function (up to 1 year after transplant). Kidney transplants postoperative function was rated as good if creatinine was less than 1.9, fair if creatinine was 2 to 2.9, and poor if creatinine was 3. Donor age ranged from 2 years to 54 years. Toxins involved in donation included ethanol (n = 8), cocaine (n = 5), carbon monoxide (5), barbiturates (2) and lead (1), six patients had multiple drugs. Two of the nine recipients of livers died intraoperatively, both unrelated to organ function. Thirty-two kidneys were transplanted with 28 having good 10-day postoperative function, three having fair postoperative function, and one (cocaine donor) having poor postoperative function. One kidney transplanted from a cocaine donor had a thrombosed graft 5 days postoperatively. Deaths involving toxins in general does not seem to be a contraindication to donation of liver and kidney for transplantation.