Organ Donation Legalities and Management

Organ Donation Legalities

• A driver's license or donor card signature is legally binding for organ donation, overriding family consent.

Contraindications for Donation

• Age over 80 years
• HIV infection
• Active metastatic cancer
• Prolonged hypotension or hypothermia
• Active infection
• Disseminated intravascular coagulation (DIC)
• Sickle cell anemia or other hemoglobinopathy

Donor Management

• Aggressive donor management enhances the number and quality of retrieved organs, improving transplant outcomes.

Organ Transplantation Statistics

• The kidney is the most transplanted organ.
• The lung is the least transplanted organ.

Anesthesia for Donation

• Anesthesia is necessary for organ donation after brain death (DBD).
• Anesthesia is not required for donation after cardiac death (DCD).

History of Organ Transplantation

• First solid organ transplant: kidney between identical twins (1954)
• Liver, lung, heart, pancreas transplants began in the 1960s
• Cyclosporine (1978) significantly improved transplant success by reducing rejection

Organ Types and Transplant Statistics

• Transplantable organs include: heart, kidneys, lungs, pancreas, liver, intestines, corneas, skin, tendons, bone, and heart valves
• Most frequently transplanted: kidney and liver (whole or segmental)

Organ Procurement and Allocation

• United Network for Organ Sharing (UNOS): links organ procurement and transplant centers in the US
• Matching and Ranking: based on blood type, tissue match, time on waiting list, immune status, and geographic distance
• Other factors considered: pediatric patients, payback agreements, dual-organ recipients, organ failure following recent transplant, and medical urgency (heart, liver, intestines)

Contraindications for Organ Donation

• Absolute: age >80 years, HIV, active metastatic cancer, prolonged hypotension or hypothermia, active infection, DIC, hemoglobinopathy
• Relative: non-CNS or skin malignancy in remission, hypertension, diabetes, age >70 years, hepatitis B/C, smoking history

Donor Organ Viability

• Donor health at death determines viability of organs
• Organs deteriorate faster after cardiac arrest
• Tissues like bone, skin, heart valves, and corneas can be retrieved up to 24 hours after death

Minimizing Ischemic Time (Warm Ischemic Time)

• Time between cardiac death and organ preservation impacts viability
• Goal: Minimize warm ischemic time
• Organ-specific time limits:
  • Heart and liver: 30 minutes
  • Kidneys and pancreas: 60 minutes

Organ Procurement: Consent and Legal Considerations

• Organ donation can be documented through various methods like driver's license, donor card, living will, or verbal communication with family.
• States with first-person consent laws make an individual's signature legally binding, eliminating the need for family consent.
• The Uniform Anatomical Gift Act (UAGA) empowers OPOs to seek consent for organ donation, even in the absence of family permission.
• The National Organ Transplant Act (1984) prohibits the sale of organs for transplantation.

Physiological Responses Associated with Brain Death

• Brain death results from severe rostral-caudal ischemia, triggering a cascade of physiological responses.
• Intense sympathetic activity is the initial response, aiming to maintain cerebral perfusion pressure.
• Medullary ischemia leads to loss of thermoregulatory control and endocrine dysfunction due to hypothalamic and pituitary impairment.
• Brainstem herniation is associated with cardiovascular instability, pulmonary complications, and potential cardiopulmonary arrest.
• A systemic inflammatory response occurs in brain death, affecting vascular resistance and potentially increasing immune sensitivity after transplantation.

Preoperative Management of Organ Donors

• Hemodynamic instability poses a significant challenge for organ donors, requiring aggressive fluid resuscitation and cardiovascular support.
• Colloids are preferred over crystalloids to prevent pulmonary edema and organ congestion.
• Inotropic medications like dopamine, dobutamine, norepinephrine, or epinephrine are commonly used to maintain perfusion pressures.
• Anesthetic management aims to achieve optimal hemodynamic parameters, including MAP >60 mm Hg, CVP 12 mm Hg, SVR 800 to 1200 dynes/cm', SBP > 100 mm Hg, and CI > 2.5.
• Bradycardia is effectively treated with isoproterenol, epinephrine, or cardiac pacing due to the limited effect of atropine in brain death.
• Electrolyte monitoring is crucial to maintain optimal levels of sodium and potassium.
• Lung function is significantly compromised in brain death, with limited recovery potential.

Pulmonary Complications Associated with Brain Death

• Neurogenic pulmonary edema is caused by elevated systemic vascular resistance (SVR), left atrial and pulmonary capillary pressure.
• The inflammatory response contributes to lung damage due to the release of proteases, cytokines, and leukotrienes.
• Coagulopathy may lead to pulmonary micro emboli
• Decreased SVR after brain death increases ventilation/perfusion mismatch
• Additional factors affecting pulmonary function include aspiration, pulmonary contusion, excessive fluid resuscitation, atelectasis, and barotrauma.
• Pulmonary management includes:
  • Large tidal volumes (12 to 15 mL/kg)
  • Low peak inspiratory pressure (PIP), ideally 90%
  • Arterial oxygen pressure (PaO2) >60 mm Hg
  • Arterial carbon dioxide pressure (PaCO2) 30 to 35 mm Hg
  • Arterial pH 7.35 to 7.45
• Other measures:
  • Careful fluid management
  • Chest physiotherapy
  • Frequent suctioning
  • Administration of antibiotics (cefazolin or equivalent)

Endocrine Dysfunction

• Diabetes insipidus (DI) is caused by a lack of antidiuretic hormone (ADH) production or release due to damage to the hypothalamus or pituitary gland. Treatment includes vasopressin or desmopressin acetate (DDAVP [1-deamino-D-arginine vasopressin]).
• Hypovolemia associated with DI is corrected with hypotonic saline or dextrose and water and electrolyte replacement.
• Thyroid Dysfunction is characterized by low triiodothyronine (T3), a result of decreased thyroid-stimulating hormone (TSH) secretion and reduced conversion of thyroxine (T4) to T3.
• Hyperglycemia is caused by sympathetically mediated hyperglycemia and depletion of insulin stores and is best managed with an insulin infusion.
• Prolonged hypothermia is associated with cardiac depression, cold diuresis, coagulopathy, and reduced tissue oxygenation.

Coagulation Abnormalities

• Coagulation abnormalities occur due to the release of thromboplastin, tissue plasminogen, and fibrinogen from necrotic brain tissue and reduced platelet aggregation secondary to hypothermia.
• A dilutional coagulopathy can occur due to the excessive use of crystalloids for resuscitation.
• Blood products like fresh frozen plasma (FFP), platelets, and cryoprecipitate are used to correct coagulation abnormalities.
• Immediate organ retrieval is recommended for severe fibrinolysis resistant to therapy.

Hypovolemia

• Contributing factors to hypovolemia include fluid restriction for cerebral edema treatment, DI, hemorrhage, hyperglycemic osmotic diuresis, cold diuresis, and decreased SVR.
• Treatment involves administering crystalloids, colloids, and red blood cells to maintain a systolic blood pressure ( SBP) >100 mm Hg, urine output > 1 mL/kg/ hr, and hematocrit >30%.

Brain Death Criteria

• Diagnosis of brain death is primarily based on the absence of brainstem reflexes and respiratory effort.
• Optional confirmatory tests:
  • Electroencephalogram (EEG)
  • Cerebral blood flow studies
  • Brain-stem auditory-evoked responses (BAER)
• Potentially reversible causes of coma should be ruled out before confirming brain death. These include hypothermia, metabolic disturbances, medications, hypoxia, or hypocarbia.
• The Glasgow Coma Scale (GCS) is used to assess the status of the central nervous system (CNS) and provides an objective and reliable method.

Brain death and Spinal Automatism

• Spinal automatism (Lazarus sign) includes limb flexion, gasping motions, and head-turning.
• Spinal automatism occurs at the spinal cord level, not brain activity.
• Spinal automatism is more common in young adults.

Brainstem Reflexes

• Absent Pupillary Light Reflex: Pupils are mid-sized (4-6mm) but do not constrict when light is shone on them.
• Absent Oculocephalic Reflex (Doll's Eyes): Eyes remain fixed when the head is turned from side to side.
• Absent Oculovestibular Reflex (Caloric Reflex): No eye movement occurs when iced saline is irrigated into the ear canal.
• Absent Corneal Reflex (Blink Reflex): No eyelid closure occurs when the cornea is stimulated.
• Apnea Test:
  • After ventilation with 100% O2, the patient is disconnected from the ventilator while receiving continuous positive airway pressure (CPAP).
  • Respiratory effort is observed for 10 minutes.
  • Brain death is confirmed if there is no spontaneous breathing and PaCO2 is greater than 55-60 mmHg.

Laboratory Evaluation of Organ Donors

• Requires a variety of tests for both DBD (Donation after Brain Death) and DCD (Donation after Cardiac Death) donors.
• Blood: CBC, glucose, electrolytes, BUN, creatinine, ABG, ABO and HLA typing, blood cultures, VDRL, HIV, EBV, CMV, HTLV-1, Hepatitis B and C serologies.
• Other: Sputum and urine cultures.
• Heart Donors: ECG, CXR, echocardiogram, CK, CK-MB, troponin levels.
• Lung Donors: Serial ABGs, CXR, bronchoscopy.
• Pancreas Donors: Serial blood glucose, amylase, and lipase levels.
• Liver Donors: LFTs, PTT, PT.

Diabetes Insipidus (DI)

• ADH is produced by the hypothalamus and stored and released from the posterior pituitary.
• ADH increases water permeability, leading to water reabsorption in the renal collecting ducts and distal convoluted tubule.
• Central DI:
  • Deficiency of ADH due to autoimmune disease, malignancy, head trauma, intracranial tumor, infection, renal disease, or vascular disease.
  • Signs include:
    • Polyuria (urine output ≥ 25 mL/kg/hr) with a specific gravity of ≤ 1.005.
    • Lethargy, excessive thirst, hypernatremia, tachycardia, hypotension, fatigue, vomiting, and seizures.
• Nephrogenic DI:
  • The kidney fails to respond to ADH.
  • Causes: Lithium, amphotericin B, demeclocycline, hypercalcemia.
• Diagnosis: Restrict fluids and monitor plasma and urine sodium, urine specific gravity, and ADH levels.
• Treatment:
  • Central DI: Chlorpropamide, carbamazepine, clofibrate (stimulate ADH production).
  • Nephrogenic DI: Indomethacin, hydrochlorothiazide, or amiloride.
• DI in Organ Donors: Occurs in 70-80% of DBD donors.
  • Treatment:
    • Vasopressin (if hemodynamically unstable).
    • Desmopressin (if hemodynamically stable).
    • Frequent electrolyte monitoring.

Role of Steroids in Organ Donor Management

• Increase tissue oxygenation.
• Attenuate the effects of proinflammatory cytokines.
• Improve donor organ function.
• Increase the number of organs transplanted from each donor.
• Improve graft survival, especially in heart and lung recipients.
• Dosage: Methylprednisolone 15-30 mg/kg every 24 hours.
  • Additional 30 mg/kg 1-2 hours before organ procurement to protect the heart and lungs.

Declaring Death in a DCD Donor

• DCD donor: A potential donor who is expected to expire within 60 minutes after extubation.
• Observation Period: 5 minutes to confirm lack of cardiac reanimation.
• Cardiac Reanimation Criteria: Flat ECG tracing, flat pressure arterial line tracing, absence of carotid pulse.
• Hemodynamic Criteria: Systolic blood pressure < 100 mmHg, and hematocrit > 30%.
• Fluid Management: Colloids are preferred for lung and pancreas donors to increase organ viability.
• Electrolyte Monitoring: Serial evaluation of electrolytes, glucose, hemoglobin, hematocrit, and ABGs is crucial for heart and lung donors.
• Intestinal Decontamination: A Betadine and amphotericin B solution is inserted via a nasogastric tube to decontaminate the intestinal tract.
• Organ Procurement Sequence: Organs are removed in order of their susceptibility to ischemia, with the heart first and the kidneys last.
• Anesthesia Termination: Anesthesia care is terminated when the aorta is cross-clamped and the heart removed.
• CPR and Organ Viability: CPR can preserve the viability of some organs in case of premature cardiac arrest.
• Maximum Transplantation Time: Varies according to organ type, ranging from 5 hours for the heart to 3 days for kidneys.

Organ Transplant Survival Rates

• Over 163,000 individuals in the United States are living with a functioning organ transplant
• The highest one-year survival rates are for kidney and pancreas recipients (95% to 98%)
• One-year survival rates for liver, intestine, lung, and heart recipients range from 81% to 91%
• The lowest survival rate (75%) is seen with heart-lung recipients
• DCD kidney graft survival is similar to DBD kidney, but DCD liver graft survival is significantly lower than DBD liver

Professional Conflicts with Organ Donation

• While most health care providers support organ donation, some may experience conflict when shifting focus from donor to recipient
• Families may question the ability of health care providers to provide quality end-of-life care
• Physicians and nurses should focus on quality end-of-life care for the donor and not be involved in the organ procurement or transplant process
• The OPO is responsible for evaluating the donor, obtaining consent, coordinating procurement and transplantation, and supporting the family during bereavement
• The treating physician declares death using brain or cardiac criteria; the transplant team cannot participate in end-of-life care or the declaration of death
• Anesthetists providing anesthesia for organ procurement are required to withdraw life support, which may contradict professional standards

Surgical Consent vs Driver's License or Donor Card

• Surgical consent informs the patient about the procedure, risks, benefits, and alternative options
• A signed driver's license or donor card is a limited informed consent, lacking detailed explanation of risks and benefits
• Most donors do not know that their end-of-life care may be significantly altered and managed by the OPO, not their treating physician
• The OPO can dictate premortem medications and procedures (heparin, catheters, cannula), as well as when to discontinue mechanical ventilation
• To restrict end-of-life care to their personal physician, voluntary donors must specify this directive in a living will