Organ Donation Flashcards
Organ Procurement and Transplantation Network (OPTN)
- established by congress in 1984
- facilitates organ matching/allocation process
- collects and manages data about organ donation and transplantation
- professional and public education
United Network for Organ Sharing (UNOS)
- administers the OPTN under contract with health resources and services admin of the US department of health and human services
- develop policy
- monitor and enforce processes of OPTN
- maintain OPTN membership and review application
- organ transplant centers HAVE to be members of this
organ most transplanted as of 2020
kidney
organs transplanted from most to least frequent
- kidney
- liver
- pancreas
- kidney/pancreas
- heart
- lung
- heart/lung
- intestine
current waiting list for all organs
117,204
demand is HIGH
allograft/homograft
-tissue for transplant derived from a non-twin donor of the same species
autograft
- tissue for transplant derived from the recipient
- example = burn patient skin graft
orthotopic
-implanting an organ in the anatomic position after the native organ is removed
heterotopic
-implanting an organ leaving the native organ in place
xenograft/heterograft
- tissue grafted from one species to another
- example is using pig valve for valve replacements
- also some full organ transplant from animal to human
Major Histocompatibility Complex (MHC) antigens
- cell surface glycoproteins that establish immunologic identity
- class I human leukocyte antigen (HLA) A-B-C classic transplant antigens
- class II HLA DR-DQ-DP on activated t cells are antibodies that will attack foreign objects
major blood group antigens
ABO potent transplant antigens
Kidney HLA tissue typing
- ABO and HLA matching, T-Cell cross match and PRA (panel reactive antibody profile)
- also pancreas and ideally lung (but sometimes not lung because time is of the essence)
heart/liver HLA tissue typing
-ABO and other factors such as size/urgency
types of organ donors
- cadaveric; donation after brain death (DBD)
- non-heart beating donor; donation after cardiac death (DCD)
- living donor - kidney paired donation (sometimes liver too)
cadaveric or donation after brain death
- previously healthy
- brain death established
- negative for extracranial malignancy
- absence of untreatable infection
donor mechanism of injury in DBD
usually violent in some way - MVC, GSW, asphyxiation
determination of brain death history
- first talked about in mid 1950s
- Harvard med school published criteria for brain death in 1968 because this is when 1st heart transplant occurred
- president commission for the study of ethical problems in medicine 1981; defined brain as primary organ
what must be done to determine brain death
- r/o reversible cerebral dysfunction
- nothing else that could be masking as brain death
- hypothermia
- hypotension
- metabolic/endocrine instability
- drug OD
- R/O and like that for 12-14 hours then can proceed with brain death testing
criteria on brain death exam
- comatose - unresponsive to verbal stimuli
- absence of cerebral cortical function - non-responsive to painful stimulus; absence of spontaneous movement
- loss of brain stem function - reflexes
- supporting studies - EEG and cerebral flow studies; sometimes HAVE to do this
neurological absence of brain stem function (also part of brain death exam)
- pupillary response to light
- corneal reflex
- oculocephalic reflex absent, dolls eye response
- oculovestibular reflex absent, cold caloric test
- gag and cough reflex
- absent respiratory reflex (apnea test)
occulcephalic reflex absent
- eyes fixed when head rotated sideways - BAD
- normal for eyes to move the opposite way
oculovestibular reflex absent
- irrigate ear with cold water
- eyes have nystagmus toward stimulated ear
apnea test
- 100% FiO2 for 10 min
- normalized PaCO2 - confirmed by ABG
- T-piece for 7-10 minutes
- repeat ABG
- PaCO2 on repeat > 60 mmHg
- absence of spontaneous ventilation
- sometimes unable to complete due to patient stability - may need EEG or flow study
non-heart beating organ donor (or donation after cardiac death)
- S/P cardiac arrest
- death anticipated within 1-2 hours (ideally sooner) after life support withdrawn
- comatose, unresponsive; may have some brainstem activity but poor quality of life
- warm ischemia time
- controlled vs uncontrolled
kidney living organ donor
- donor is usually healthy
- advantages = decreased cold ischemic time (organ will work better) and less time on waiting list
- can be laparoscopic or open
- selection of kidney = usually of L side bc easier to get to and longer vascular access
- anesthetic = GA; standard monitors; maintain UOP with mannitol/lasix; heparin and protamine prior to clamping
partial liver living organ donor
- more common in peds vs adults
- not done as much anymore
- liver regenerates over time
- adult usually R side = V, VI, VII, VIII
- peds usually L side = II, III, IV
- anesthetic technique is GA
- monitoring - CVP, A line, Large bore IV
- +/- epidural (controversial in literature)
- drop CVP with transection to around 5 mmHg or less
- NGT FO SURE!!! to evacuate the stomach
- no N2O, dont want bowel expansion
- cell saver or isovolemic hemodilution
- clamp hepatic –> VR decrease 20% (good to volume load before this)
organ preservation strategies
- keep organ healthy so it will work for the recipient
- hypothermia decrease metabolism
- maintain cellular integrity
- prevent cellular swelling, vasospasm and build up of toxic metabolism
- provide source of energy
Ex-vivo organ preservation
- rapid cooling at 4 degrees celcius
- preservative solutions
- removed in order of susceptibility
preservative solutions
- UW - intrabdominal organs (hyperkalemia)
- celsior/cardioplegia (heart)
order of susceptibility of removal
- heart
- lung
- liver
- kidney
heart max preservation time
4-6 hours
liver max preservation time
8-12 hours
*Barash used to say up to 24 hours
pancreas max preservation time
12-18 hours
kidney max preservation time
24-36 horus
donor anesthesia
- brain death = established prior to arrival in OR
- goal = preserve organ perfusion and oxygenation
- hypotension - loss of descending vasomotor control
- decreased CO and SVR
- decreased oxygenation = atelectasis, aspiration, pulmonary edema
- DI = destruction of hypothalamic-pituitary axis
- bradycardia = loss of vagal motor nucleus, increased ICP
- visceral and somatic reflexes = will still have these
visceral and somatic reflexes
- still present after brain death
- donor can still respond to pain and have some motor movements
- may need opioids and muscle relaxant
MAP for preserving organ function
60-100 mmHg
UOP for preserving organ function
0.5-3 mL/kg/hr
Hgb for preserving organ function
> 10 g/dL
Glucose for preserving organ function
120-180 mg/dL
CVP for preserving organ function
5-10 mmHg
FiO2 for preserving organ function
<40% if tolerated for lung retrieval especially to minimize effects of O2 toxicity
PEEP for preserving organ function
no more than 10 cm H2O; now more liberal though
SaO2 for preserving organ function
> 95%
PaO2 for preserving organ function
> 100 mmHg
Core temp for preserving organ function
> 35 C
fluids for organ donation
colloids first vs crystalloid, especially for lungs
vasopressors in order of use
dopamine
vasopresson (recommended for heart)
dobutamine
epinephrine
which vasopressor do you NOT use
phenylephrine; decreases splanchnic BF which is BAD for abdominal perfusion if those organs are being procured
bradycardia for organ donation
- resistant to atropine because no vasomotor control
- use a direct acting agent like isoproterenol
DI in organ donation
- vasopressin or DDAVP
- free water - D5W 0.45% NS = fluid type based on hourly serum electrolytes
other things for donor anesthesia
- standard monitors, A line, CVP, Swan
- pressors and SNP/NTG/beta blocker
- PRBCs/FFB
- Heparin
- mannitol/lasix
- methylprednisolone (protects heart, lungs and kidneys from ischemia)
- PGE1 (lung membrane stabilization)
- long acting NDMR
special considerations for donor anesthesia
- confirm ETT placement with surgical team
- midline incision from neck to pubis
- ensure you know organs that are to be procured
- sternal saw –> drop lungs
- organs mobilized and dissected
- aorta cross-clamped and vent turned off
- heart lung procurement –> continue to manually ventilate at 4 breaths/min