Indian Transplant Newsletter. Vol.17 Issue No.: 52 November 2017 - February 2018
Champions of lung transplantation
Indian Transplant Newsletter.
Vol.17 Issue No.: 52 November 2017 - February 2018
Print ISSN 0972 - 1568
“You cannot believe in God until you believe in yourself,” quoted by Swami Vivekananda was the strongest message in my mind in the morning of a beautiful day in November 2017. It was 8 AM in the morning. I was driving to work. I was hopeful to make some headway in taking care of a patient who was very sick. I just met this patient in my clinic in the past week, and now developed acute respiratory failure. As I was parking my car, my mind was filled with these questions. Can this patient live? Can this patient get out alive from this horrific respiratory failure? Can we find a suitable pair of lungs before it's too late? My beeper, which kept ringing, interrupted my thoughts. It read, “ Dr. Kaza, please call. We are primary on an offer for one of our patients. We have 30 minutes to respond.” I rushed to the nearest computer. I logged into our United Nations Organ Sharing Network (UNOS). Every 10 minutes, a patient is listed for transplantation in UNOS.
The Division of Transplantation is under Office of Special programs,which is categorized under Health Resources and Services Administration (HRSA). The HRSA is governed by the Department of Health and Human Services in the United States of America. The Division of Transplantation has two service lines, Organ Procurement and Transplantation Network (OPTN), and the United States Scientific Registry of Organ Transplant Recipients (SRTR). The United Network for Organ Sharing website (UNOS) is where all patients awaiting organ transplantation are listed. The urgency for transplantation for lung transplantation is based on “Lung Allocation Score” or LAS score. The LAS score is based on wait list urgency, i.e. risk of death in the first year awaiting lung transplantation and post transplant survival, i.e. chances of survival in the first year with lung transplantation. So, sicker the patient, higher the LAS score. The first step, in organ allocation, is elimination. All the transplant candidates on the wait list, who are not suitable due to blood type, height, weight, and other medical factors, are automatically screened. Then, a secure computer application process will determine the order in which candidates will receive offers. There are 58 local donor service areas and 11 regions that are used for organ allocation. However, since heart and lungs have less time to be transplanted, radius from donor hospital is used instead of regions for organ allocation.
In the United States of America, the 58 local donor service areas are managed by Organ Procurement Organizations (OPO). The OPOs are structured to provide services such as donor family support, management of organ donors and professional education. There is an onsite OPO coordinator who takes the responsibility to take donor history, especially, social history, family history and other relevant medical history. This information along with basic labs, such as complete blood count, basic metabolic panel, liver function tests, arterial blood gas, report of chest x-ray or any other radiological imaging is uploaded into UNOS donor net website. Each of us physicians involved in organ transplantation, have secure log in identification and password. The OPO coordinator works with the donor hospital to offer option of organ donation, informed consent, coordinate organ recovery and provide follow-up information to donor family and involved hospital staff. Determination of death is by circulatory, respiratory criteria or neurological criteria as per standard guidelines. Authorizations for organ donation are usually higher when personnel with experience and expertise approach donor families. During such challenging situations, it is imperative for transplant coordinators from OPO (not from donor or recipient hospital) to be able to manage conflict between family, treating physician andnhospital. The OPO coordinator is the central point in managing the donor while receiving recommendations about donor management from recipient teams.
There are multiple studies that demonstrate, improved donor lung utilization when donor management protocols are used with intensive care teams in donor hospitals. The important aspects of donor management that are included in standardized protocols are discussed below.
Brain death and prior insults disrupt the neuro-hormonal balance. The initial sympathetic surge leads to hypertension followed by neurogenic hypotension. The resulting pro-inflammatory cytokines can cause acute lung injury or capillary leak. Thus, additional volume will cause flooding and damage the lungs further. There are three major aspects of donor management for lung retrieval.
1. Volume Therapy and hemodynamics
2. Ventilator management
3. Screening for infection
1.Volume Therapy and Hemodynamics: Managing volume status is always challenging with lung recruitment. The other abdominal organs, kidney teams have liberal management strategy. Initial assessment of volume status is done with monitoring tools such as central venous catheter, arterial line and other non-invasive measures; initial goals are central venous pressure, less than 10,mean arterial pressure 60-70 mmHg, urine output, 1-3 ml/kg/hr, left ventricular ejection fraction 45% or higher. There is no clear data for preferred resuscitation fluid; hypovolemic shock is corrected with replacement fluid available. 5% albumin as colloid is also considered in this setting.
Normal saline is not advised in hyperchloremic metabolic acidosis, ringer’s lactate is not advised in hypoosmolar state. Hydroxyethylstarch is contraindicated since it can cause acute kidney injury, coagulopathy, acute hypervolemia and right ventricular compromise. Once hypovolemia is corrected, management of hemodynamics is the next crucial step. Vasopressin is first line agent recommended in refractory shock. Norepinephrine or phenylephrine are used as second line for vasodilatory shock. Dopamine, dobutamine, epinephrine are used for primary cardiac pump failure. Monitoring is essential while using vasoactive drugs, with lactate, arterial blood gas, or echocardiogram, mixed venous oxygen saturation. Excessive vasopressor use can cause airway injury and lead to bronchial stenosis after lung transplantation.
2. Ventilator Management: Lung protective ventilation at 6ml/kg is a reasonable strategy. Recruitment with higher positive end expiratory pressure (PEEP) of 8-10 cm H O, gentle diuresis with lasix is indicated. 2 In some centers, pressure controlled ventilation directed at higher mean airway pressure to improve oxygenation is targeted. Several OPO coordinators have recruitment strategies, some of which include, increasing PEEP for a short duration of less than a minute. In addition, closed circuit tracheal suction, higher PEEP at 8-10cm H O, decrease 2 in fractional inspired oxygen to 50% or lower are now standard guidelines for donor management.
3. Screening for Infection: It is absolutely necessary to evaluate for donor-derived infections. Apart from routine screening serologies that are sent, evaluating for hepatitis, HIV, syphilis, additional recommendations include blood cultures, urine culture and bronchial washing for surveillance. It is important to know if donor had infection at presentation or was it hospital acquired. It is imperative to treat donor infection prior to organ retrieval. The recipient should be treated with antibiotics related to specific pathogen at least for 7-14 days after organ implantation. Bronchoscopy is standard procedure and the findings are reported in UNOS website. Airway surveillance to evaluate and suction mucus plugs, blood or aspirated material significantly improves oxygenation.
Additional therapeutic strategies include managing polyuria, electrolyte imbalance, and steroid and thyroid supplementation prior to organ retrieval.Coming back to my situation, I had several challenges in managing the potential donor. Once decision about organ donation is made, the process had to be completed within 6 hours.
The onsite OPO coordinator was the key personnel involved in keeping lines of communication open. Later, diabetes insipidus, significant polyuria leading to hypernatremia, hypotension, and liberal fluids, worsening oxygenation complicated the situation.
Following the standard donor management protocol, with minimizing fluid, use of vasopressin, bronchoscopy for airway clearance further improved oxygenation; ventilator strategies described above, gentle diuresis also improved oxygenation. General criteria for acceptance of donor lungs are PaO on arterial blood gas of 300 or higher on 100% 2 oxygen on the ventilator with normal PCO and pH. Ultimately, with the 2 tremendous coordinated effort and systems in place, lung transplantation became a reality and provided hope to person who was walking a fine line between life and death.
In summary, organ donation is the key aspect of providing hope in a recipient’s life. Coordination of the process is a very important aspect and coordinators are the lifelines for these complicated, challenging, exhaustive processes. As exemplified in another one of my favorite quotes from Swami Vivekananda “ Arise! Awake! And stop not until the goal is reached,” opportunities are few, need is large, so let us work together to achieve our common goal of being a part of saving lives.
Shortage of organs has resulted in exploitation of the poor and marginalized of the society, thus making the region prone to illegal organ trafficking. The growth of the deceased donation programme has been slow and only two (India and Sri Lanka) of the eight countries in the region have been able to take up the deceased donations programmes. Sri Lanka has recently invited MOHAN Foundation to conduct a workshop to help the deceased donation programme and improve the deceased donation rate in the country. The Buddhists in Sri Lanka have a high eye donation rate and Sri Lanka has been world famous for its successful eye donation programme and is a net exporter of corneas. If Sri Lanka can set systems in place it has generally been felt that it can improve on the deceased donation rate and help it to achieve some degree of self-sufficiency and overcome the organ shortage.
- Dr. Vaidehi Kaza, M.D., M.P.H
Associate Director, Lung Transplant Program
Associate Professor, Division of Pulmonary Crtical Care Medicine
University of Texas Southwestern Medical Center
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- Keywords: lung transplantation,UNOS donor website