Block 3: heart transplant and AKI Flashcards
What are the class 1 indications for cardiac transplant
- Cardiogenic shock requiring mechanical assistance, refractory HF with continuous inotropic infusion
- NYHF functional class 3 or 4 with poor 12 mn prognosis
- progressive symptoms on maximal therapy
- severe symptomatic hypertrophic or restrictive cardiomegaly
- medically refractory angina with unstable anatomy for revascularization
- life-threatening ventricular arrhythmias despite aggressive medical and device interventions
- cardiac tumors with low likelihood of mets
- hypoplastic left heart and complex congenital heart disease
What are some contraindications to cardiac transplant
1) Severe pulmonary HTN (>6 wood units not responsive to vasodilators)
2) active infection
3) uncontrollable malignancy
4) irreversible end-organ damage (hepatic, renal or pulmonary)
5) pulmonary infarction
6) age >60
7) diabetes mellitus with end-organ damage
8) severe cerebral or peripheral vascular disease
What blood tests should be done before a cardiac transplant
BMP, FBC, LFTs, UA, coags, TSH, UDS, ETOH level, HIV, hepatitis panel, PPD, CMV IgG, RPR/VDRL, PRA (panel of reactive antibodies), ABO and Rh blood type and lipids
What is the donor criteria for a cardiac transplant
Age <53 (<45 ideally), size- donor and recipient must have a size difference of <20kg. ABO blood type- <15% reactivity on the test allows transplant. >15% needs a lymphocyte cross-match test which takes 6 hrs and can delay the procedure. Brain death is required for any cadaveric organ donation- there should be no hypothermia, hypotension, metabolic abnormalities or drug intoxication
How do you match cardiac transplant
based on severity of disease, ABO blood type, response to PRA, donor recipient weight ratio, geographical location and length of time at current status
Immunosuppressants and cardiac transplant
Cyclosporine (and azothioprine)
Started on day of operative (IV then converted to PO 3 days later)
Types of cardiac transplant
Orthotopic (most common)- native heart is completely removed and replaced
biatrial anastomosis: recipient and donor atria are connected together
bicaval anastomosis- superior vena cava and ventricle are connected together
heterotopic heart transplant (2 hearts in the chest)
What investigations are used to check for rejection post cardiac transplant
Heart muscle biopsy (weekly for first 3-6 weeks, every 3 months for the first year, and then once a year)
What are the possible complications in cardiac transplant
Aortic pseudoaneurysm or rupture at cannulation site, or haemorrhagic pericardial effusion due to bleeding or coagulopathy. Medical- severe tricuspid regurg, RV failure (PA compression, PAH) or LV failure (ischaemia, operative injury and acute rejection). Rhythm disturbance- asystole, complete heart block, sinus node dysfunction with bradycardia (25% permanent, most resolve in 1-2 weeks), AF or VT. Coagulopathy induced by cardiopulmonary bypass. Resp failure- cardiogenic pulmonary oedema, noncardiogenic pulmonary oedema or infection. Renal or hepatic insufficiency- drugs or CHF
Types of cardiac rejection
- Hyperacute: pre-existig IgG antibodies usually directed against donor HLA proteins. Occurs in mins-hours
- Acute cellular rejection: most common in 2-3 months
- Allograft vasculopathy/chronic rejection: coronary heart disease in transplanted heart from immune mediated injury
- CMV is the most common infection transmitted
What is used to prevent chronic rejection in cardiac transplant
Immunosuppression, statins, diltiazem and antioxidant vitamins
Causes of death cardiac transplant
- Most common cause of death: cardiac allograft vasculopathy (chronic rejection)
- Most common cause of death in the first year after: acute rejection and infection
- If a patient has N+V admit them so they can get their immunosuppressants UV
Indications for lung transplant
1) untreatable ESRD: pulmonary, parenchymal, or vascular
2) Absence of other medical illness
3) projected life expectancy < 2yrs
4) NYHA Class III or IV fuctional level
5) Forced expiratory volume FEV <30%
6) BODE < 5
7) PA pressure >50 mmHg
8) Rehabilitation potential
9) Acceptable nutritional status
Contraindications for lung transplant
Incurable malignancy, age >69, active or incurable infection- HIV, Hep C, other major organ system damage (kidney, liver), morbid obesity, alcohol, smoking or drug abuse, corticosteroid therapy, or revious CT surgery (case by case)
The requirements of a donor for lung transplant
<50, infection free, pO2 >140 on 40% O2 and pO2 >300 on 100% O2, peak inspiratory pressure <30cm H2O and smoking Hx <20 pack years with no COPD
Follow up needed for lung transplant
- Lung biopsies at 2 and 4-6 weeks, 12 weeks, 6 months and then yearly.
- Home spirometry daily and tacrolimus level, basic labs, CMV PCR and spirometry at each visit.
Complications for lung transplant
Short term: Bleeding, fluid and electrolyte problems, arrhythmias, reperfusion injury, airway complications, GI complications, pulmonary infarction, acute rejection,
Long term: Bleeding, fluid and electrolyte problems, arrhythmias, reperfusion injury, airway complications, GI complications, pulmonary infarction, acute rejection,
Main cause of mortality and morbidity: infections
Combined heart and lung transplant
Indications: Congenital heart disease (eg. eisenmernger’s syndrome- no. 1 indication), idiopathic PAH, and CF patients
Complications: HTN, renal dysfunction, hyperlipidaemia, diabetes, bronchiolitis obliterans, and coronary artery vasculopathy
AKI definition
A rapid deterioration in renal function over hours or days resulting in a sudden decrease in GFR. Can lead to dysregulation of fluid balance, acid-base homeostasis and electrolytes.
AKI complications
Hyperkalaemia, Hypo/hypernatraemia, Hypercalcaemia, Metabolic acidosis, Pulmonary oedema, Hypertension, Uraemic encephalopathy, Uraemic pericarditis
