Anesthesia for the organ donor Flashcards
The Organ Procurement and Tranpslantation Network facilitates
organ matching/allocation process
collects & manages data about organ donation & transplantation
professional and public education
United Network for organ sharing is responsible for
developing policy
monitoring/enforcing processes of OPTN
maintain OPTN membership & review applications
Describe allograft/homograft.
tissue for transplant derived from a non-twin donor of the same species (i.e. human to human)
Describe autograft.
tissue for transplant derived from the recipient
ex. burn patient
Describe orthotopic.
implanting an organ in the anatomic position after the native organ is removed
Describe heterotopic
implanting an organ leaving the native organ in place
ex. kidney
Describe xenograft/heterograft.
tissue grafted from one species to another
ex. pig valves for valve replacement
Describe immunology as it relates to organ transplant
major histocompatibilty complex antigens
major blood group antigens
varying degrees of HLA tissue type
Major histocompatibility complex antigens (MHC) are
cell surface glycoproteins that establish immunologic identity
- Class 1- Human leukocyte antigen (HLA) A-B-C (classic transplant antigens)
- Class II- HLA Dr-DQ-DP (on activated T cells)
Major blood group antigens include
A-B-O potent transplant antigens
When preparing for kidney transplant, the following immunology is tested
ABO & HLA matching, T-cell cross match & PRA (panel reactive antibody profile)
When preparing for heart & liver transplant, the following immunology is tested
ABO & other factors such as size
tends to have higher urgency d/t less warm time so HLA is often done after transplant
Types of organ donors include
cadaveric: donation after brain death (DBD)
non-heart beating organ donor; donation after cardiac death (DCD)
living donor- kidney paired donation
Considerations for donation after brain death include
previously healthy brain death established negative for extracranial malignancy absence of untreatable infection donor mechanism of injury- typically trauma which involves lots of ethical, religious, and social factors
When determining brain death, reversible cerebral dysfunction must be ruled out including
hypothermia
hypotension
metabolic/endocrine instability
drug overdose- like barbiturate overdose (causes isoelectric EEG)
must wait 12-24 hours after ruling these out to proceed with brain death workup
Determination of brain death criteria include
comatose- unresponsive to verbal stimuli
loss of brain stem function- reflexes
supporting studies- EEG, cerebral flow studies
absence of cerebral cortical function- non-responsive to painful stimulus, absence of spontaneous movement
Neurological absence of brain stem function includes
pupillary response to light
corneal reflex
oculocephalic reflex absent- doll’s eye response
oculovestibular reflex absent- “Cold caloric test”
gag & cough reflex
absent respiratory reflex (apnea test)
Describe the doll’s eye response.
normal for eyes to move opposite way if fixed when head is rotated so with doll’s eye they’ll remain fixed
Describe the cold caloric test.
irrigating auditory canal with cold fluid & have nystagmus and they deviate towards ear that is being stimulated (normal); remain fixed if they do not
Describe the absent respiratory reflex.
100% fio2 for 10 minutes to normalize PaO2 then for 7-10 minute put them on a T piece and observe to see no respiratory attempt & a PaCO2 >60 is positive
Describe the apnea test.
100% fiO2 for 10 minutes
normalized PaCO2- confirmed by ABG, T-piece 7-10 minutes, repeat ABG
PaCO2 >60 mmHg
absence of spontaneous ventilation
Describe non-heart beating organ donation.
-may still have brainstem activity intact but decision is made to remove patient from life support
S/P cardiac arrest- death anticipated within 1-2 hrs after life support is withdrawn
warm ischemia time- controlled vs. uncontrolled
The transplant team cannot be a part of
the decision making process nor can declare brain death
Describe living organ donors for kidneys
.donor characteristics- donors are healthy and generally hemodynamically stable
Advantages to living kidney donor include
decreased cold ischemic time
less time on waiting list
Describe anesthetic considerations for living kidney donors.
standard monitors
maintain urine output- mannitol/lasix
pharmacologic therapy- heparin (given prior to clamping renal artery)/protamine
selection of kidney- usually left side b/c more readily accessible & has longer vascular access
laparoscopic or open
Describe partial liver donation for pediatrics.
typically give left side b/c appropriate size
typically segments 2 & 3
Describe partial liver donation for adults
usually use right side & 5, 6, 7 or 8
In liver donation, the donor is left with
1/3rd the size of the liver; original size of organ will be achieved in 6 months although full functionality is still not achieved this quickly
Describe anesthetic considerations for the partial liver donation.
monitoring- CVP/art–> venous return falls by 50% when you crossclamp hepatic pedicle so volume load prior
+/- epidural placement
drop CVP with transection
NGT
No N2O!–> don’t want bowel expansion
cell saver
keep fluids to a minimum b/c don’t want a lot of blood loss nor engorge the liver
Describe organ preservation strategies.
hypothermia- decreases metabolism
preservative solutions- maintain cellular integrity, provide a source of energy, prevent cellular swelling vasospasm & build up of toxic metabolites
Implantation and reperfusion are times when
organ damage can still occur
Describe Ex-vivo.
rapid cooling at 4 degrees C
preservative solution- different solutions for different types of organs
UW- intraabdominal organs- hyperkalemia
celsior/cardioplegia- heart
removed in order of susceptibility- heart, lung, liver, & kidney
Describe the order of removal of organs.
heart, lung, liver and kidney
based on susceptibility
The max preservation time for the heart & lungs are
4-6 hours
The max preservation time for the liver is
8-12 hours; up to 24 hours
The max preservation time for the pancreas is
12-18 hours.
The max preservation time for the kidney is
24-36 hours
Brain death is established
prior to arrival in OR
The goal for donor anesthesia is to
preserve organ perfusion & oxygenation
Presentation for donor anesthesia includes
hypotension decreased CO & SVR decreased oxygenation diabetes insipidus bradycardia visceral & somatic reflexes
Describe why hypotension occurs in brain death patients.
loss of descending vasomotor control
Describe why decreased oxygenation occurs in brain death.
aspiration/atelectasis/ pulmonary edema
Describe why diabetes insipidus occurs in brain death.
destruction of hypothalamic-pituitary axis
Describe why bradycardia occurs in brain death.
loss of vagal motor nucleus, increased ICP
Describe considerations for visceral and somatic reflexes.
reflex pressor response
spinal-somatic reflexes
may still respond to pain or have muscle twitching so may give opioids, NMBD, & volatiles
Preserving organ function for donor anesthesia includes.
MAP 60-100 mmHg urine output (0.5 to 3 mL/kg/hr) Hgb >10.0 gm/dL glucose 120-180 mg/dL- Organ function delayed if hyperglycemia CVP 5-10 mmHg FiO2 <40% (if tolerated) for lung retrieval-minimize effects of O2 toxicity PEEP no more than 10 cm H2O SaO2 >95% PaO2 >100 mmHg Core temp >35 degrees C
Describe how to treat hypotension for donor anesthesia.
fluid first!!! colloid/crystalloid- colloid first for lung transplant
vasopressors- dopamine, vasopressin (recommended for heart donor), dobutamine, epinephrine
Describe use of phenylephrine for donor anesthesia.
phenylephrine decreases sphlancnic blood flow & don’t want this if taking abdominal organs
Describe the use of norepinephrine for donor anesthesia.
produces impaired graft function if used
This vasopressor is recommended for heart donors
vasopressin
If a donor patient experiences bradycardia, give
isoproterenol
pt will be resistant to atropine
If a donor patient develops diabetes insipidus
use vasopressin or DDAVP
free water- D5W 0.45% NS- fluid type based on hourly serum electrolytes
monitor electrolytes
Describe lines/considerations for donor anesthesia
standard monitors, art line, CVP, swan pressors and SNP/NTG/beta blocker PRBCs (keep Hgb at 10)/ FFP heparin mannitol/lasix methylprednisolone PGE1 long acting NDMR
PGE1 may be given for
lung retrieval for membrane stabilization
Special considerations for donor anesthesia include
confirm ETT placement with surgical team
midline incision, neck to pubis
sternal saw–> drop lungs
organs mobilized & dissected
aorta cross-clamped & ventilator turned off
heart lung procurement–> continue to ventilate manually about 4 bpm
