transplant Flashcards
What immune cells are typically involved in organ rejection?
T Lymphocytes (acquired, cell-mediated immunity) there is an antibody-antigen interaction
How does transplantation impact VO2 Max?
decrease to 50-60% of typical due to deconditioning/myopathy and changes in cellular respiration that may be caused by cyclosporine
What medical issues are common following transplant?
anemia, hypertension, electrolyte abnormalities, excessive weight gain, myopathies, glucose intolerance, osteoporosis and AVN
infections, malignancies, renal failure risk increased with cyclosporine
What is the 50% survival time following heart transplant?
10 years
Indications for heart transplant
Chronic disease, single organ failure
NYHA class III or IV with VO2 20%; no infection or malignancy; no pulmonary infarction; some pulmonary resistance and perfusion requirements; no renal or hepatic failure; no diabetic organ failure; FVC>50% and FEV1 >1L; no evidence of current substance abuse; able to comply with medical advice; adequate financial resources
Donor match criteria: ABO blood type; within +/-20% of recipient mass; negative prospective cytotoxic T-cell crossmatch (not usually checked prospectively); allograft ischemic time <4-5 hours
NYHA Class 1
No limitation in normal physical activity
Can complete any activity requiring ≤ 7 mets:
Carry 11 kg up 8 steps
Carry objects weighing 36 kg
Shovel snow
Spade soil
Ski ; Play squash, handball or basketball
Jog/walk 8 km/h
NYHA Class 2
Ordinary physical activity can cause fatigue, dyspnea, palpitation, angina
Can complete any activity requiring ≤ 5 mets:
Typically ind. With ADL/ IADL but may have sypmtoms
Sexual intercourse without stopping
Garden
Roller skate
Walk 7 km/h on level ground
NYHA class 3
less than ordinary physical activity can cause fatigue, dyspnea, palpitation, angina
Can complete any activity requiring ≤ 2 - 3 mets: Shower or dress without stopping Strip and make bed Clean windows Play golf Walk 4 km/h
NYHA Class 4
has symptoms at rest
Cannot do or cannot complete any activity requiring ≥ 2 mets; cannot do any of the above activities with prolonged rest and/ or assistance
What are the different heart transplant surgeries?
Heterotopic–recipient heart remains in place and is connected to donor heart–used only when donor heart too small or weak to function alone, but allows donor heart to be removed if rejected
Orthotopic–recipient heart is removed by cutting great vessels and left atrium (pulmonary veins preserved)–>anastamoses at pulmonary artery and aorta, left atrium, IVC and SVC (or some of right atrium can be preserved)
Both are done using median sternotomy
How does body compensate for loss of innervation to heart after transplantation?
Loss of vagal nerve stimulation=no suppression of HR at AV and SA nodes
Loss of sympathetic (????)=no reflex tachycardia in response to hypovolumia/hypotension
body increases circulating catecholamines to increase cardiac output via starling mechanism (SV)–patient may need longer warm up and cool down for appropriate cardiac response
What ECG changes may be present after heart transplant?
2 p-waves (2 SA nodes, but recipient SA signals not transmitted past suture/anastamosis)
time frames for rejection of heart transplant
hyperacute: within minutes to hours due to antibodies already present in blood stream interacting with donor organ
acute: within 6-12 months, t-lymphocyte mediated
chronic: longer-term due to antibodies, lymphocytes, etc–variety of mechs/less well defined
what are signs and symptoms of rejection in heart transplant?
fever, increased dyspnea, decreased exercise tolerance, dysrhythmia, decreased contractility
What does chronic rejection in heart transplant cause?
Post-transplant vasculopathy (concentric wall thickening of coronary arteries)
What are indications for lung transplant?
Advanced lung disease (50% mortality 24-36 months???)
Progressive dyspnea
Decreasing Function
High Lung Allocation Score
Good Match available (Blood type, Body type,CMV)
contraindications: Smoking – usually must prove abstinence; Extremes of weight (cachexia obesity);Profound debility; Symptomatic osteoporosis leading to disability; Other chronic medical conditions poorly controlled or associated with end-organ damage
E.g.: CAD/ MI; DM; renal disease; hepatic disease
Psychosocial issues (substance abuse, medical noncompliance, severe psychiatric illness)
When are double lung transplants indicated
- Cystic fibrosis–can move between lungs
- better survival, esp under 60
Mean 50% survival after lung transplant
7-8 years
What is the Lung Allocation Score (LAS)?
Score 0-100, higher=higher priority for transplant
What goes in to determining LAS?
Forced vital capacity Pulmonary artery systolic pressure Supplemental O2 required at rest Age Body mass index Presence/absence of insulin-dependent diabetes Functional status I-IV (NYHA Class) Six-minute walk distance Ventilator use Pulmonary capillary wedge pressure Serum creatinine Diagnosis (cystic fibrosis and IPF favored over emphysema)
Lung concerns immediately after transplantation
edema/secretions (increased hydrostatic pressure and capillary permeability)
hypoxemia (diffusion of O2 impaired)
loss of lymphatics increases interstitial fluid
loss of innervation decreases mucocilliary clearance and cough
What are possible surgical approaches for lung transplantation?
median sternotomy,bilateral transverse thoracosternotomy (“clam shell”), thoracotomy
Systemic concerns following lung transplant
Hemodynamic instability: hypovolemia
myocardial irritability
depressed myocardial contractility
supraventricular dysrhythmias
What activities should be the focus of inpatient rehab following lung transplant?
Deep breathing, airway clearance, pain control, prevent deconditioning
What activities should be the focus of outpatient rehab following lung transplant?
Increasing fitness (DOE will be early limiter) and pain control
watch for signs of rejection or infection
What are signs of infection following lung transplant?
SUBTLE fever/ malaise/ cough reduced airflow FEV1 & FVC oxygen desaturation reduced exercise capacity
What are signs of acute rejection following lung transplant?
Biopsy Histological diagnosis 0-no symptoms, no evidence; no treatment 1-mild 2-moderate 3-severe-rare 4-severe-rare Rx: ↑ immunosuppression
What are signs of chronic rejection following lung transplant?
Bronchiolitis Obliterans Syndrome (BOS)
Diagnosis of exclusion
Worsening Pulmonary Function Testing
Rx: ↑ immunosuppression
retransplant
What is the result of chronic rejection following lung transplant?
Bronchiolitis Obliterans Syndrome (BOS) (fixed obstruction of airway due to inflammation and scarring. Symptoms include dry cough, shortness of breath, wheezing)
What is VO2 max following lung transplant
about 40-60% expected max, if patient completes aerobic training–can be worse
