BTS 2012 Report – Optimising the use of the donor pool: the Spanish experience

by Maria Dalby reporting on the presentation by José Ramón Nuñez, Hospital Clinico San Carlos, Madrid, Spain.  A nation-wide protocol for retrieving organs after cardiac death outside the hospital has dramatically increased the availability of organs from younger, healthy donors in Spain. José Ramón Nuñez, one of the initiators behind the protocol, outlined the rationale and design of the protocol and some of the clinical outcomes.

At 35 per million Spain has one of the highest rates of organ donation in Europe. Despite this, the waiting list for organ transplants continues to grow and it is estimated that 10 patients die every day on European transplant waiting lists. In addition, the average donor age has increased in recent years: in 1992, 69% of the donor pool were under 45 years old and only 10% were over 60 years; in 2011, these figures had almost been reversed with just 18.4% of donors being under 45 and 53.7% over 60. Improved road safety and public information campaigns have led to a reduction in donation after brain death, from 43% of the overall donor pool in 1992 to just 5% in 2011. In light of this, a protocol was devised under which ambulance paramedic staff can identify potential cardiac death donors when attending cardiac arrest cases outside the hospital. The eligibility criteria are strict: there must have been witnesses to the occurrence to allow the exact time to be determined. The emergency crew must arrive and begin cardio-pulmonary resuscitation within 15 minutes. The patient/potential donor must be under 55 years with normal appearance (ie no signs of venopunctures or similar) and there must be no abdominal or thoracic bleeding trauma. Once irreversible cardiac arrest has been diagnosed, the emergency crew will continue with cardiac massage, respiration and liquids until they arrive in the hospital to preserve the organs for donation. The potential donor must arrive in the hospital within 120 minutes, and an extracorporeal membrane oxygenation (ECMO) device must be connected within 150 minutes from the onset of cardiac arrest. The emergency crew hand over to the intensive care unit staff who sign the death certificate.

Under current Spanish law, this procedure does not require next-of-kin consent, but the transplant team must obtain permission from an on-call magistrate – this permission is normally given by ‘passive consent’ – if no response is received within 15 minutes, the procedure can go ahead. Once the ECMO has been connected, the team has 4 hours to contact the family and prepare for the transplantation. The lungs are preserved using topical cooling with 4 litres of saline at 4°C.

From the first implementation of this protocol in 1995, the proportion of cardiac death donors has increased dramatically, to the point where in 2011, three out of four donors were cardiac death donors who had died outside the hospital. In terms of clinical outcomes, the 1- and 5-year graft survival rates amongst renal transplant patients were similar and very high (85-90%) in cardiac death and brain death donors; the 10-year graft survival rates were almost identical in the two groups (81.8% in brain death donors v 82% in cardiac death donors). Serum creatinine levels indicated a high degree or graft function in both groups after 1 year; however, at 5 years graft function was significantly poorer in the cardiac death donor group.¹ Data from patients receiving lung transplants from cardiac death donors and brain death donors showed that the 5-year patient survival rate was significantly higher in the former group. Professor Nuñez concluded that the use of cardiac death donors under this protocol has been effective for increasing the donor pool, and added that high-quality ambulance paramedic teams has been critical to this success.

Reference:

1. Sánchez-Fructuoso AI, Marques M, Prats D, et al. Victims of cardiac arrest occurring outside the hospital: a source of transplantable kidneys. Ann Intern Med 2006; 145(3): 157-164