Transplantation Flashcards
What are the goals of transplant?
-decrease disabling symptoms
-improve functional capacity
-improve health related QOL
-increase life expectancy
What organ has the greatest wait time for transplant?
kidney- 5 years (due to number of people on the transplant list)
-there is much greater need for organs compared to the numbers that are available
Thorough evaluation for a transplant candidate (common outcome measures:
Continuous distribution composite allocation score (CAS)
A tool that uses statistical modeling that is used to
estimate each candidate’s organ specific CAS range
using various patient factors.
FACTORS:
-med urgency
-likelihood of recipient survival over next 5 years post-transplant
-biological factors (blood type, height, immune sensitivity)
-age when listed
-prior living donor status
-donor and recipient hospital regions
What is the most common age range on the waiting list for an organ transplant?
50-64
Infection versus rejection and immunosuppression:
-use of immunosuppressive drugs:
–> needed because the body will automatically have a negative reaction to the new organ
(need to dampen down the effect of the immune system)
-too much immunosuppression could lead to infection, malignancy, toxicity (lack of oncogenic regulation–> malignancy)
What is organ transplant rejection?
Failure of immunosuppression medications to prevent activation of immune effector cells
-primarily mediated by T lymphocytes
–> involves both cellular (macrophages; cytotoxic T cells) and humoral immune responses (antigen-antibodies)
-white blood cells try to attack invading tissues–> leading to rejection
Common Post HEART Transplant Operative Issues
PSYCHIATRIC:
-unfulfilled expectations –> expects to return to pre-disease level
-complex medical regimen
-moodiness/agitation
-post-op complications
-unaccustomed lifestyle
MEDICAL:
-anemia
-hypertension
-electrolyte abnormalities
-weight gain
-glucose intolerance/DM
-myopathy
-osteoporosis (avascular necrosis)
EXERCISE LIMITATIONS:
-VO2max at 50-60% of normal
– myopathy, DEconditioning
– altered cellular respiration at level of mitochondria
—> related to immunosuppressive medications (affect function of mitochondria)
LONG TERM MEDICAL CONCERNS:
-injection/rejection: acute and long term
-malignancies
-renal failure
What is the common reason for a heart transplant?
-heart failure
** usually pre-renal syndrome is corrected with a heart transplant
Is the prevalence of heart failure in America increasing or decreasing?
increasing
Heart Transplant Indications:
-chronic, irreversible disease
-usually only single organ dysfunction
-correction of primary dysfunction could lead to improvement in secondary problems
What classes on the NYHA Classification Scale are most common for heart failure transplant patients?
NYHA CLASS III
NYHA CLASS IV
NYHA CLASS I
no symptoms with normal phys activity
normal functional status
NYHA CLASS II
mild symptoms with normal physical activity
comfortable at rest
slight limitation of functional status
NYHA CLASS III
-moderate symptoms with less than normal physical activity
-comfortable only at rest
-marked limitation of functional status
NYHA CLASS IV
-severe symptoms with features of heart failure with minimal physical activity and even at rest
** symptomatic at rest
-severe limitation of functional status
What is the most common decade of age that ppl get heart transplants?
5th-6th
What is the median survival (in years) for a heart transplant patient?
12 years
Is pediatric heart transplant survival better or worse than adult?
better
If a person survives 1 year after heart transplant surgery than the likelihood of them surviving longer _____
increases
In the bicaval technique of a heart transplant, does the donated or original organ drive the heart beat?
the heart beat and rhythm is driven by the donated organ
Orthotopic versus heterotopic heart transplant:
ORTHOTOPIC:
-remove the native heart and fully implant the damaged heart
HETEROTOPIC:
-Heterotopic heart transplant in which the recipient’s heart is not excised and the donor’s heart is implanted into the recipient’s chest (rare)
Information about the Denervated Heart:
-electrical activity cannot cross suture line
–> recipient atrial activity present but not conducted (2 P waves); native SA node still fires and native RA may still contract
–> donor atrium denervated but source of electrophysiologic response
-loss of SNS, PNS, innervation to donor heart
–> vagal stimulation has not effect on sinus and AV nodes
–> no reflex tachycardia in response to hypovolemia, hypotension (lack of reflex tachycardia)
-rely on increases in SV via Frank-Starling mechanism and circulating catecholamine to increase CO with activity
–> warm up and cool down are critical
** hormonal response from adrenal medulla is key
Signs of acute heart transplant rejection:
-fever
-dysrhythmias
-reduced contractility
-increased dyspnea
-decreased exercise tolerance
Signs of chronic heart transplant rejection:
-post transplant vasculopathy–> similar to CAD
-concentric wall thickening
What is a similar physiological effect of both acute heart transplant rejection and chronic heart transplant rejection?
immune injury to myocardial cell wall and intima of coronary arteries
Even though VO2max is typically 50-60% lower compared to baseline after a heart transplant, what is true about exercise after heart transplant?
Exercise can still improve outcomes after heart transplant
Who are candidates for lung transplant?
-advanced lung disease
-50% mortality in 24-36 months
-progressive dyspnea (MRC 4/5)
-decreasing function
-high Lung Allocation Score: The lung allocation score estimates the severity of each candidates’ illness and his or her chance of success following a lung transplant.
-Good Match Based on:
–> blood type
–> body type
–> Cytomegalovirus (decreases match possibility)
** consider benefits of transplant versus risk of waiting**
MRC dyspnea scale
1- I only get breathless with strenuous exercise.
2- I get short of breath when hurrying on the level ground or walking up a slight hill.
3- I walk slower than ppl of the same age on the level bc of breathlessness, or I have to stop for breath when walking on my own pace on the level.
4- I stop for breath after walking about 100 m or after a few minutes on the level.
5- I am too breathless to leave the house or I am breathless when dressing or undressing.
CIs to transplant
-smoking- must prove abstinence
-extremes of weight (cachexia–> obesity)
-profound debility
-symptomatic OP leading to disability
-chronic med conditions that are poorly controlled or associated with end-organ damage
–> CAD, MI, DM, renal disease, hepatic disease
-psychosocial issues (substance abuse, etc)
Is BL or unilateral lung transplant more common for an individual with CF?
-bilateral due to risk of infection
Are outcomes better for BL or unilateral lung transplants?
-bilateral
(usually one lung transplant is performed after the other rather than both at the same time)
What is the most common age for lung transplant?
-50-59
-then 60-65
-the percentage of pediatric lung transplants is going down as time goes on whereas the percentage of older adults transplants is going up as time goes on
Survival in years for heart versus lung transplant?
HEART: 12 years
LUNG: a little over 6 years (a bit greater for adults compared to children)
Difference in pediatric and adult lung transplant survival conditional on survival to 1 Year:
Pediatric survival is better than adults
**OVERALL SURVIVAL RATE IS HIGHER FOR BOTH
PEDIATRIC: 9.1
ADULT: 8.3
Is the survival rate better for single lung or double lung transplants?
double
Survival rates for pediatric lung transplant patients are greater than adult lung transplant patients at what year following tx?
about 7.5-8 years is when pediatric survival rates begin to be greater than adult
Most common reason for pediatric lung transplant:
cystic fibrosis
Most common dx for adult lung transplant:
COPD
IIP - Idiopathic interstitial pneumonias (IIPs)
Considerations following lung transplant:
Pulmonary issues:
-loss of pulmonary lymphatics
-denervated lung
–> impaired cough reflex (reduced)
-pulmonary edema
-increased secretions
3 types of surgical approaches for lung transplant:
1) Bilateral transverse thoracosternotomy (open up rib case/sternum anteriorly)
2) Thoracotomy
3) Median Sternotomy
Ex training after lung transplant:
Outcomes associated with PT and ex training after transplant:
INTENSITY: 3x/week, 3 months; ex training included symptom-limited cycling, walking, stair climbing and resistance exercise
OUTCOMES:
-improved ex capacity –> aerobic capacity increases compared to pre-transplant levels but it is at 50-60% predicted levels
-improves “myopathy”
-improved bone health (BMD)
-improved health related QOL
Various causes of exercise limitation post-transplant (oxygen transport system)
SKELETAL MUSCLE
-deconditioning
-dec oxidative enzymes
-dec type I fibers
-impaired mitochondrial oxygen extraction
-dec. ATP and IMP
-corticosteroid-induced myopathy
LUNG
-oxyhemoglobin desaturation
-abnormal lung mechanics
-prior to transplant, ppl are deconditioned
VASCULATURE
-impaired vasodilation (due to immunosuppressant drug)
BLOOD
-medication-induced anemia
HEART
-deconditioning
-cardiac denervation in recipients of heart-lung transplants
Why does the transplant recipient have long-term issues with infection?
Transplant recipients are at risk for long-term infections because they take immunosuppressive medications to prevent transplant rejection. These medications reduce the immune system’s ability to fight infections, and a suppressed immune system has fewer white blood cells, which raises the risk of infection.
Exercise following heart transplant:
-delayed HR acceleration at the start of exercise in heart transplant patients
-loss of SNS, PNS, innervation to donor heart
–> vagal stimulation has not effect on sinus and AV nodes
–> no reflex tachycardia in response to hypovolemia, hypotension (lack of reflex tachycardia)
-rely on increases in SV via Frank-Starling mechanism and circulating catecholamine to increase CO with activity
–> warm up and cool down are critical
** hormonal response from adrenal medulla is key
**MAKE SURE TO FACTOR IN WARM UP AND COOL DOWN PERIODS