Hemodynamic responses to noxious stimuli in brain-dead organ donors

The case report presents evidence for the spinal origin of the marked hypertensive reponses to noxious stimuli that may occur in organ donors who fulfill the commonly accepted criteria of brain death. Cardiovascular spinal reflex activity does not invalidate these criteria. For the first time, the catecholamine plasma concentrations have been determined during spinal pressor reflex activity. Circulating epinephrine increased more markedly than norepinephrine in both cases, rising to 4.7 and 44 times the baseline concentration respectively. The relation between plasma norpinephrine and epinephrine suggests involvement of the adrenal medulla in the reflex arc. The literature on spinal hemodynamic reflexes is reviewed.     

Japanese ethos and organ transplantation from brain-dead donors

A trend observed since the 1980s in the Japanese academic scene is the overturning of Hippocratic ethics by American individualistic bioethics. However, the Japanese ethos is more sympathetic to personalistic bioethics rooted in Hippocratic ethics, which assumes the universal view of the 'interdependent self' clearly marked off from the 'independent self' specific to American culture. In Japan, organ transplantation from brain-dead donors is promoted despite the lack of consensus on whether brain death signifies death of the individual. From the viewpoint of personalistic bioethics, this situation is problematic because it violates the dictum primum non nocere of the Hippocratic Oath. We should therefore first establish consensus on brain death and then promote a 'culture of donation' based on human dignity.     

Entropy is more resistant to artifacts than bispectral index in brain-dead organ donors

Objective To evaluate the usefulness of entropy and the bispectral index (BIS) in brain-dead subjects. Design and setting A prospective, open, nonselective, observational study in the university hospital. Patients and participants 16 brain-dead organ donors. Interventions Time-domain electroencephalography (EEG), spectral entropy of the EEG, and BIS were recorded during solid organ harvest. Measurements and results State entropy differed significantly from 0 (isoelectric EEG) 28%, response entropy 29%, and BIS 68% of the total recorded time. The median values during the operation were state entropy 0.0, response entropy 0.0, and BIS 3.0. In four of 16 organ donors studied the EEG was not isoelectric, and nonreactive rhythmic activity was noted in time-domain EEG. After excluding the results from subjects with persistent residual EEG activity state entropy, response entropy, and BIS values differed from zero 17%, 18%, and 62% of the recorded time, respectively. Median values were 0.0, 0.0, and 2.0 for state entropy, response entropy, and BIS, respectively. The highest index values in entropy and BIS monitoring were recorded without neuromuscular blockade. The main sources of artifacts were electrocauterization, 50-Hz artifact, handling of the donor, ballistocardiography, electromyography, and electrocardiography. Conclusion Both entropy and BIS showed nonzero values due to artifacts after brain death diagnosis. BIS was more liable to artifacts than entropy. Neither of these indices are diagnostic tools, and care should be taken when interpreting EEG and EEG-derived indices in the evaluation of brain death. This article is discussed in the editorial available at:     

Inhalational anesthesia for organ procurement: potential indications for administering inhalational anesthesia in the brain-dead organ donor

Organs needed for transplantation far outweigh their availability. There is minimal research regarding perioperative care of the brain-dead organ donor during the procurement procedure. Current research attributes a great deal of organ damage to autonomic or sympathetic storm that occurs during brain death. Literature searches were performed with the terms brain death, organ donor, organ procurement, anesthesia and organ donor, anesthesia and brain death, anesthesia and organ procurement, inhalational anesthetics and organ procurement, and inhalational anesthetics and brain dead. Additional resources were obtained from reference lists of published articles. The literature review showed there is a lack of published studies researching the use of inhalational anesthetics in organ procurement. No studies have been published evaluating the effect of preconditioning with inhalational agents (administering 1.3 minimal alveolar concentration of an inhalational agent for the 20 minutes before periods of ischemia) in the brain-dead organ donor population. Further studies are required to determine if administration of inhalational anesthetics reduces catecholamine release occurring with surgical stimulation during the organ procurement procedure and whether this technique increases viability of transplanted organs. Anesthetic preconditioning before the ischemic period may reduce ischemia-reperfusion injury in transplanted organs, further increasing viability of transplanted organs.     

Identification of potential organ donors of advanced age in EDs

Objective

In France and in Belgium, as in many countries, there is a shortage of organs for transplantation, which has led to strategies to recruit older potential donors who may die of stroke.

Methods

We conducted a post hoc analysis to identify potential organ donors with cardiac function among a population of dying patients in emergency departments. This population had been selected for a separate multicenter prospective observational study. We identified patients who died of a neurologic cause but had no clinical findings affecting their donor status.

Results

Of 2420 patients in the study, 407 died of a neurologic cause; and 233 of these were excluded because of clinical factors that made them ineligible as organ donors. The remaining 174 patients (7.2% of dying patients) could be considered potential organ donors. Their mean age was 75.2 ± 11 years. Sixty-eight (39%) were intubated, and 60 of these (34.5%) were mechanically ventilated. In addition, 94 patients (54%) died within 12 hours (median, 9.3 hours) after admission; and 13 (7%) died while receiving a maximum level of care. No diagnostic procedures were performed to assess brain death.

Conclusion

A significant number of patients who die in emergency departments could be organ donors, including approximately 7% between 60 and 85 years of age with life-threatening neurologic diseases. However, this percentage may be reduced by family opposition. Emergency physicians should collaborate with intensive care units and local organ donation teams to optimize end-of-life care and maximize the number of potential donors.     

Renal functional reserve in kidney donors

The glomerular filtration rates of 28 subjects, who had undergone donor nephrectomy up to 22 years previously, were measured before and after ingestion of an 80 g protein meal. A renal functional reserve was demonstrated in all cases. There was no evidence of loss of this reserve with time after nephrectomy. This study supports the view that long-term compensatory hyperfiltration of the remaining kidney after donor nephrectomy is not damaging, at least over this time scale.     

Neuroendocrine disorders in brain-dead donors at the time of multiorgan harvesting]

Changes in the level of antidiuretic hormone (ADH), adrenocorticotropic hormone (ACTH), somatotropic hormone (STH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), prolactin (PL), thyroxin (T4), triiodothyronine (T3) and thyroxine-binding globulin (TBG) have been assessed before and during multiorgan excision in 22 donors with brain death. A progressing decrease in ADH blood supply and changes in ACTH, STH, FSH and PL content have been recorded. No regularities have been observed in LH level changes. TSH and thyroid hormone changes were in most cases characterized by a gradual decrease in their plasma levels. A drop in T3 concentration observed at the initial stage of the study was most pronounced with practically normal T4 and TBG values, that also decreased by the moment of heart excision. It has been concluded that brain death is accompanied by a considerable neuroendocrine disfunction and a marked syndrome of low T3 content.     

Ventilatory and hemodynamic management of potential organ donors: an observational survey

OBJECTIVE: To determine the current standard ventilatory and cardiovascular management in potential organ donors. DESIGN: Prospective, multiple-center, observational survey. SETTING: A total of 15 intensive care units in 13 hospitals in Piedmont, Italy. PATIENTS: A total of 34 brain-dead patients enrolled in 6 months. MEASUREMENTS AND MAIN RESULTS: Demographics and reasons for lung transplant exclusion were recorded. Ventilatory and hemodynamic variables were compared before and after confirmation of brain death. A total of 23 potential donors were ineligible for lung donation based on pulmonary status and age. Of the 11 eligible lung donors, only two donated the lungs because five had Pao2/Fio2 ratios of <300 and four were ineligible for logistic problems. Tidal volume was 10 +/- 2 mL/kg, positive end-expiratory pressure was 3.3 +/- 2.7 cm H2O, Fio2 was 50% +/- 18% before brain death diagnosis, and no changes were made after brain death confirmation. In potential lung donors, apnea tests were performed with apneic oxygenation after disconnection from the ventilator in all cases; tracheal suction was performed with an open circuit in eight cases, and no recruitment maneuvers were performed. Crystalloid infusion was increased after diagnosis of brain death from 187 +/- 151 to 275 +/- 158 mL/hr (p < .05), and central venous pressure increased from 6 +/- 3 to 7 +/- 3 mm Hg (p < .05). Inotropic support was used in 24 donors (70%). CONCLUSIONS: Five of 11 potential lung donors (45%) had a Pao2/Fio2 ratio of <300, making them ineligible for lung donation. After the diagnosis of brain death, ventilatory management remained the same, no maneuvers for prevention of derecruitment of the lung were performed, and cardiovascular management was modified to optimize peripheral organ perfusion. These data represent the current standard of care for ventilatory management of potential organ donors and may be suboptimal in preserving lung function.     

Combined measurements of N-terminal pro-brain natriuretic peptide and cardiac troponins in potential organ donors

Objective Brain death may induce cardiac dysfunction. In potential organ donors measurements of N-terminal pro-brain natriuretic peptide (NT-proBNP) and circulating cardiac troponins T and I (cTnT and cTnI), alone or in combination, are performed to investigate the accuracy of these biomarkers for early diagnosis of left ventricular systolic dysfunction. Design and setting Prospective study in a multidisciplinary intensive care unit of an university hospital. Patients 63 brain-dead patients scheduled for multiple organ harvesting. Measurements and results We measured NT-proBNP, cTnT, and cTnI and determined fractional area change (FAC) using transesophageal echocardiography. Forty-five patients had normal FAC, 9 a moderate decrease in FAC (30–50), and 9 a severe decrease in FAC (≤ 30%). NT-proBNP and cTnT concentrations were significantly higher in patients with a severe decrease in FAC than in those with a moderate decrease. Combining measurements of these two biomarkers, the sensitivity of the test to predict severe decrease in FAC increased significantly to reach 1.00 compared with the sensitivities of individual measurements. The ROC curve area of combined measurements of NT-proBNP and cTnT was significantly higher than single measurements: 0.87 vs. 0.82 for NT-proBNP, 0.78 for cTnT, and 0.72 for cTnI. Conclusions In potential organ donors the combined measurement of NT-proBNP and cTnT concentrations is more accurate than individual measurement of NT-proBNP, cTnT, and cTnI in the early diagnosis of severe left ventricular systolic dysfunction. These findings may lead to improve the quality of cardiac care of the potential organ donors.     

High prevalence of cytomegalovirus DNA in plasma samples of blood donors in connection with seroconversion

BACKGROUND: Human cytomegalovirus (CMV) is considered to latently infect blood cells. Transfusion-transmitted infection (TT-CMV) of immunocompromised patients occurs despite the use of CMV-seronegative or leukoreduced units. STUDY DESIGN AND METHODS: The prevalence of CMV DNA in plasma was investigated in 82 blood donors who had previously been seronegative for CMV and showed anti-CMV immunoglobulin G for the first time, 598 blood donors who were seropositive for at least 1 year, and 150 seronegative blood donors. In a second part of the study, the overall prevalence of CMV DNA in blood donations was assessed based on 31,745 donations. RESULTS: CMV DNA was repeatedly detected in plasma samples of 44 percent of newly seropositive donors (12%-62%, depending on the interval to the last seronegative donation). All steadily seropositive or seronegative donors were negative for the presence of CMV DNA. Detection of CMV DNA in connection with seroconversion was accompanied by significantly increased neopterin, increased alanine aminotransferase, and reduced white blood cell counts, but the sensitivity of these surrogate markers was only 71 percent. The overall prevalence of CMV DNA in blood products due to primary CMV infection of donors was at least 0.13 percent. CONCLUSION: Viremia of newly seropositive donors may be an important reason for the residual risk of TT-CMV despite leukoreduction. Furthermore, transfusion of WBC-reduced blood components from seronegative donors could imply a greater risk of TT-CMV than transfusion of WBC-reduced blood from donors who have been seropositive for at least 1 year, because window-phase donations but no reactivation could be detected in this study.     

Effect of a specialized pediatric institutional setting on organ recovery from potential donors.

BACKGROUND: The relationship between accessibility to the full range of subspecialty care available at freestanding pediatric hospitals and organ donor management and recovery rates has not been studied. OBJECTIVE: To examine current rates of recovery of organs from children for transplantation at free-standing pediatric hospitals versus all other hospitals. METHODS: Data from the hospitals served by Mid-America Transplant Services from January 2000 to July 2003 were reviewed. Organ recovery rates from freestanding children's hospitals were compared with the rates from other types of institutions. Patients were included if their organs were considered medically suitable at the time of referral for donation. RESULTS: Overall, 66% (210/318) of the potential organs were recovered. The type of institution in which the potential donor was managed did not influence the proportion of organs recovered: 67% (96/144) at freestanding children's hospitals versus 66% (114/174) at all other hospitals. A greater proportion of livers were recovered at other donor institutions than at children's hospitals (100% vs 85%, P< or =.01). CONCLUSION: The organ recovery rate from potential pediatric donors is low. In general, this rate does not appear to be affected by the type of managing pediatric institution except for liver recovery, which favors institutions that are not freestanding children's hospitals. The low rate of recovery suggests that although suitable donors are identified, appropriate referrals are made, and families provide consent for donation, major obstacles remain to the successful recovery of organs.     

Conflicts of interest in the context of end of life care for potential organ donors in Australia

End-of-life (EOL) care has become an integral part of intensive care medicine and includes the exploration of possibilities for deceased organ and tissue donation. Donation physicians are specialist doctors with expertise in EOL processes encompassing organ and tissue donation, who contribute significantly to improvements in organ and tissue donation services in many countries around the world. Donation physicians are usually also intensive care physicians, and thus they may be faced with the dual obligation of caring for dying patients and their families in the intensive care unit (ICU), whilst at the same time ensuring organ and tissue donation is considered according to best practice. This dual obligation poses specific ethical challenges that need to be carefully understood by clinicians, institutions and health care networks. These obligations are complementary and provide a unique skillset to care for dying patients and their families in the ICU.In this paper we review current controversies around EOL care in the ICU, including the use of palliative analgesia and sedation specifically with regards to withdrawal of cardiorespiratory support, the usefulness of the so-called doctrine of double effect to guide ethical decision-making, and the management of potential or perceived conflicts of interest in the context of dual professional roles.