Intraoperative catecholamine release in brain-dead organ donors is not suppressed by administration of fentanyl

[Perioperative management of the brain-dead organ donor : Anesthesia between ethics and evidence]

Hintergrund

Die Anzahl postmortal gespendeter Organe ist in Deutschland weit geringer als der Bedarf. Dies unterstreicht die Wichtigkeit einer optimalen Versorgung während des gesamten Prozesses der Organspende.

Fragestellung

Es existieren internationale Leitlinien und nationale Empfehlungen zu intensivmedizinischen organprotektiven Maßnahmen beim Organspender. Für das anästhesiologische Management fehlen evidenzbasierte Empfehlungen. Ziel dieser Übersichtsarbeit ist es, anhand der vorhandenen Evidenz die pathophysiologischen Veränderungen des irreversiblen Hirnfunktionsausfalls zu rekapitulieren und sich kritisch mit den empfohlenen Behandlungsstrategien und therapeutischen Zielgrößen auseinanderzusetzen. Auch auf ethische Aspekte der Betreuung des postmortalen Organspenders wird eingegangen.

Methode

Diese Übersichtsarbeit basiert auf einer selektiven Literaturrecherche in PubMed (Suchwörter: „brain dead donor“, „organ procurement“, „organ protective therapy“, „donor preconditioning“, „perioperative donor management“, „ethical considerations of brain dead donor“). Internationale Leitlinien und nationale Empfehlungen wurden besonders berücksichtigt.

Ergebnisse

Insgesamt ist die Evidenz für optimale intensivmedizinische und perioperative organprotektive Maßnahmen beim postmortalen Organspender sehr gering. Nationale und internationale Empfehlungen zu Zielwerten und medikamentösen Behandlungsstrategien unterscheiden sich teilweise erheblich: kontrollierte randomisierte Studien fehlen. Der Stellenwert einer Narkose zur Explantation bleibt sowohl unter pathophysiologischen Gesichtspunkten als auch aus ethischer Sicht ungeklärt.

Schlussfolgerungen

Die Kenntnisse über die pathophysiologischen Prozesse im Rahmen des irreversiblen Hirnfunktionsausfalls und die organprotektiven Maßnahmen sind ebenso Grundvoraussetzung wie die ethische Auseinandersetzung mit dem Thema postmortale Organspende. Nur dann kann das Behandlungsteam in dieser herausfordernden Situation sowohl dem Organempfänger als auch dem Organspender und seinen Angehörigen gerecht werden.

Organ-specific metabolic profiles of the liver and kidney during brain death and afterwards during normothermic machine perfusion of the kidney

We investigated metabolic changes during brain death (BD) using hyperpolarized magnetic resonance (MR) spectroscopy and ex vivo graft glucose metabolism during normothermic isolated perfused kidney (IPK) machine perfusion. BD was induced in mechanically ventilated rats by inflation of an epidurally placed catheter; sham-operated rats served as controls. Hyperpolarized [1-¹³ C]pyruvate MR spectroscopy was performed to quantify pyruvate metabolism in the liver and kidneys at 3 time points during BD, preceded by injecting hyperpolarized[1-¹³ C]pyruvate. Following BD, glucose oxidation was measured using tritium-labeled glucose (d-6-3H-glucose) during IPK reperfusion. Quantitative polymerase chain reaction and biochemistry were performed on tissue/plasma. Immediately following BD induction, lactate increased in both organs (liver: eµ_d 0.21, 95% confidence interval [CI] [-0.27, -0.15]; kidney: eµ_d 0.26, 95% CI [-0.40, -0.12]. After 4 hours of BD, alanine production decreased in the kidney (eµ_d 0.14, 95% CI [0.03, 0.25], P < .05). Hepatic lactate and alanine profiles were significantly different throughout the experiment between groups (P < .01). During IPK perfusion, renal glucose oxidation was reduced following BD vs sham animals (eµ_d 0.012, 95% CI [0.004, 0.03], P < .001). No differences in enzyme activities were found. Renal gene expression of lactate-transporter MCT4 increased following BD (P < .01). In conclusion, metabolic processes during BD can be visualized in vivo using hyperpolarized magnetic resonance imaging and with glucose oxidation during ex vivo renal machine perfusion. These techniques can detect differences in the metabolic profiles of the liver and kidney following BD.

Intraoperative management of brain-dead organ donors by anesthesiologists during an organ procurement procedure: results from a French survey

BACKGROUND

This study aimed at describing usual anesthetic practices for brain-dead donors (BDD) during an organ procurement (OP) procedure and to assess the knowledge and self-confidence of French anesthesiologists with this practice.

METHODS

An electronic and anonymous survey with closed-questions about anesthetic management of BDD was distributed to French anesthesiologists via the mailing list of the French Society of Anesthesiology and Intensive Care Medicine.

RESULTS

Four hundred fifty-eight responses were analyzed. Respondents were mainly attending physicians with more than 10 years of clinical experience. 78% of them declared being cognizant of guidelines regarding management of BDD. Advanced hemodynamic monitoring and endocrine substitution were rarely considered by respondents (31 and 35% of respondents, respectively). 98% of the respondents used crystalloids for fluid resuscitation. During the procedure, use of neuromuscular blockers, opioids and sedative agents were considered by respectively 84, 61 and 27% of the respondents. A very high level of agreement (10 [8-10], on a ten-points Likert-style scale) was reported concerning the expected impact of intraoperative anesthetic management on the primary function of grafts.

CONCLUSIONS

Declared anesthetic practice appeared in accordance with guidelines concerning organ donor management in the ICU. Further studies are needed to evaluate the specific impact of intraoperative management during this procedure and thus the need for specific anesthetic guidelines.

Brain-dead patients are not cadavers: the need to revise the definition of death in Muslim communities

The utilitarian construct of two alternative criteria of human death increases the supply of transplantable organs at the end of life. Neither the neurological criterion (heart-beating donation) nor the circulatory criterion (non-heart-beating donation) is grounded in scientific evidence but based on philosophical reasoning. A utilitarian death definition can have unintended consequences for dying Muslim patients: (1) the expedited process of determining death for retrieval of transplantable organs can lead to diagnostic errors, (2) the equivalence of brain death with human death may be incorrect, and (3) end-of-life religious values and traditional rituals may be sacrificed. Therefore, it is imperative to reevaluate the two different types and criteria of death introduced by the Resolution (Fatwa) of the Council of Islamic Jurisprudence on Resuscitation Apparatus in 1986. Although we recognize that this Fatwa was based on best scientific evidence available at that time, more recent evidence shows that it rests on outdated knowledge and understanding of the phenomenon of human death. We recommend redefining death in Islam to reaffirm the singularity of this biological phenomenon as revealed in the Quran 14 centuries ago.