According to the United Network for Organ Sharing (UNOS), every ten minutes someone is added to the national transplant waiting list, with 21 people on average dying each day while waiting for a transplant. Playing a critical role in the organ procurement process, respiratory therapists (RTs) take on a number of roles during the transplantation process.
Prior to Brain Death
Before a patient is officially declared brain dead, the key objectives of an RT include working to maintain a normal pH of 7.35-7.45, a CO2 of 35-45 and a PO2 on arterial blood gas of about 100 on the lowest possible FiO2. RTs additionally help lungs be successfully transplanted in the patient population by taking measures to prevent atelectasis and pneumonia.1
“The most important interventions for the respiratory therapist are using title volumes of 6-8ml/kg of ideal body weight. We all know that even if your lungs are the same size based on your height. This reduces barotrauma and lung injury. The lowest possible peep setting, our goal is always to get down to 5,” explained Tamara Kelley, RN and transplant coordinator with the NJ Sharing Network, in her YouTube video titled, “The Role of Respiratory Therapy in the Organ Donation Process.” “Frequent suctioning to prevent atelectasis, aspiration and a lack of swallow reflex, despite having an ET tube many oral secretions do follow that path and do go down into the lungs and our patients need more suctioning than anyone else.
While these interventions fall under the responsibilities of RTs, these healthcare professionals must also learn to effectively and efficiently collaborate with respiratory nurses-especially in intensive care unit (ICU) environments. Without a combined effort, many key interventions (such as turning at least Q2 head of bed over 30 degrees, oral care Q4 hours, suctioning and chest secretions) that assist in the lungs being transplanted would not be possible.1
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During lung transplantation, RTs must maintain close collaboration with the critical care staff, optimizing oxygenation and lung ventilation,” clarified Richard Arbour, MSN, RN, CCRN, CNRN, CCNS, CCTC, FAAN, neuroscience and critical care clinical nurse specialist at Lancaster General Hospital in Philadelphia, Pa. “They must also maintain airway clearance, monitor blood gas results, assess ventilation and collaborate with all team members including close communication with the OPO coordinator to optimize chances for patient’s lungs to be suitable for procurement and transplant.”
In order to confirm brain death and ascertain its irreversibility, professionals must rule out intoxication, abnormal metabolic states and profound hypothermia. They must also include appropriate time intervals and number of formal clinical examinations per institutional policy and state law. The multidisciplinary team must also determine and document etiology of irreversible brain injury.2
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RTs are also involved in conducting tests to determine if a patient is capable of breathing on his or her own under hypercarbic conditions. To do so, they will turn off a patient’s ventilator and monitor the results, recording his or her apparent breathing capabilities.
“Coordination with the transplant coordinator is important [during tests] because they often have very specific protocols for ventilator settings,” explained Nick Angelis, CRNA, MSN, the author of How to Succeed in Anesthesia School (And RN, PA, or Med School). “This is to avoid impeding venous return on an unstable, edematous patient and to offset the metabolic acidosis from dying tissues–transplant patients are often on sodium bicarbonate infusions, and acid base balance is very important.”
To further ascertain final brainstem herniation/brain death, RTs will administer an apnea test (AT), a mandatory examination for determining brain death (BD), providing an essential sign of definitive loss of brainstem function. However, before an AT can be carried out, the body temperature of the subject needs to be 32øC or more. It is also recommended that preoxygenation with 100% O2 be done for some time, generally for 10 min, and that hypoxia be avoided.
Lastly, RTs must ensure that the arterial PCO2 or PaCO2 is normal or above 40 mmHg, that the blood pH should be normal or in the low basic range before beginning and that a pretest systolic blood pressure of at least 90 mmHg is reached.3 Apnea testing is concluded when no breathing effort is observed at a PaCO2 of 60 mm Hg or with a 20 mm Hg increment from baseline; this indicates that the AT is positive, thereby supporting the diagnosis of brain death.
Recruitment
Being able to recruit healthy lungs for transplantation is a big issue in the field of procurement. Ways in which recruitment efforts can be enhanced are through bag suctioning with a peep valve, inspiratory holds and elevating the head of bed, closing peep maneuvers on the ventilator and turning up the peep as high as the patient will tolerate it (up to a maximum pip of 40 while monitoring their arterial blood pressure). If blood pressure declines with increased intrathoracic pressure, the RT will begin to lessen the peep setting in collaboration with the multidisciplinary team.1
“One difficulty in organizing a lung transplant is finding lungs suitable for recovery,” further explained Arbour. “Infection, fluid overload, preexisting lung disease, strong smoking history, pulmonary hypertension or blood clots in the lungs can all prevent transplantation.”
The use of chest physiotherapy (CPT) in donor patient management is another frequently utilized component of lung procurement procedures. Offering a potentially superior alternative, high frequency chest wall oscillation (HFCWO has few disadvantages associated with labor-intensive, technique and positioning-dependent CPT.
According to clinical studies and experience with HFCWO, the airway clearance device may also have the potential to help increase the quantity and quality of donor lungs by controlling the secretion-related complications that make them ineligible for transplantation. Suggested by data from a variety of patient populations, HFCWO management with regard to the obstruction of pulmonary secretions in donor lungs should ideally reduce the destructive by-products of inflammation and entrapped pathogens and improve ventilation and perfusion.4
“Donor management is conducted by trying to avoid fluid overload if possible, by meticulous pulmonary care and secretion clearance, close monitoring of lung function and by multiple chest X-rays. Also, if someone is really on the road to procurement they’re probably going to be looking at a chest CT,” said Arbour.
Donation after Cardiac Death
In terms of donation after cardiac death, respiratory remains a key component. Even after cardiac death, a patient who has endured cardiac death is still deemed living and will continue to receive quality comfort care from the hospital team in a controlled environment. However, at this point, next of kin must decide whether to withdraw life sustaining measures.
A patient’s neurologic, respiratory and clinical status must also be evaluated at this time by a transplant coordinator. This assessment can make use of the CPAP 5/5 trial (preferably for 10-15 minutes if the patient can handle it), tidal volume, respiratory rate, cuff leak, work of breathing, negative inspiratory force and arterial blood gas levels.
Ultimately, RT extubation depends on hospital policy on withdraw of life support, but organ recovery can take place after a physician acknowledges that a patient is asystolic. During this time, the patient will be transferred to the OR suite for a 5-minute observation period.
Overall, RTs play a key role in maintaining the suitability for a transplant, especially seeing as lungs are extremely sensitive to physiologic changes after brain death. With good management prior, during and after brain death, RT professionals can help make lungs available for transplant and guide the success of the operation.
References
1. YouTube. The Role of Respiratory Therapy in the Organ Donation Process. https://www.youtube.com/watch?v=vt8-GdXf-YA
2. Rutgers School of Health Related Professions. The Role of the Respiratory Therapist in Organ Donation. http://shrp.rutgers.edu/dept/primary_care/rspth/north/documents/colon_RT_role_revised.pdf
3. National Center for Biotechnology Information, U.S. National Library of Medicine. Brain death diagnosis and apnea test safety. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2824942/
4. RespirTech. Lung Procurement for Transplantation, Use In. http://www.respirtech.com/evidence-experience-with-airway-clearance-therapy/annotated-bibliography/clinical-research/lung-procurement-for-transplantation-use-in
Lindsey Nolen is a staff writer. Contact: [email protected].
