Brain Death and Anesthesia Flashcards
UNOS and its responsibilities/role
united network for organ sharing
have to be a member of this organization to do anything or get reimbursement
develops policy, monitors/enforce processes of OPTN (organ procurement and transplantation network), maintain OPTN membership and review applications
allograft/homograft
tissue for transplant derived from a non twin donor of the same species. human to human like kidney donation
autograft
tissue forr transplant derived from the recipient ex)burn patient donating own skin
orthotopic
implanting organ in anatomic position after native organ is removed
heterotopic
implanting an organ leaving the native organ in place (like kidneys)
xenograft/heterograft
tissue grafted from one species to another ex) pig valves, ex)baboon heart transplanted into child (who is v dead)
Major histocompatibility complex (MHC) antigens
cell surface glycoproteins that establish immunologic identity.
MHC antigens classes
class 1: human leukocyte antigen (HLA) a-b-c (classic transplant antigens) class 2: HLA DR-DQ-DP (on activated T cells) increase in class II HLA usually increases PRA and makes matching more difficult
major blood group antigens
ABO potent transplant antigens. usually tested for kidney, pancreas, and lungs but sometimes have to test post lung transplant
describe varying degrees of HLA tissue typing
kidney: ABO and HLA matching, t cell cost match and PRA (panel reactive antibody profile)
heart, liver- ABO and other factors such as size/urgency
types of organ donors
cadaveric (deceased): donation after brain death (DBD)
non heart beating organ donor; donation after cardiac death (DCD)
living donor: kidney paired donation
deceased organ donors: 4 criteria to meet and something to consider
crate: previously healthy, brain death established, negative for extra cranial malignancy, absence of untreatable infection. consider donor mechanism of injury (usually violent)
definition of brain death
irreversible cessation of all functions of the brain including the brainstem.
for determination of brain death, you have to rule out these reasons for reversible cerebral dysfunction
hypothermia hypotension metabolic/endocrine instability drug overdose (look at chart in miller)
when doing determination of brain death examination, explain the criteria
comatose (unresponsive to verbal stimuli) absence of cerebral cortical function (non responsive to painful stimulus. absence of spontaneous movement) loss of brain stem function (absence of reflexes) supporting studies (EEG, cerebral blood flow studies) neurological absence of brainstem function
when doing determination of brain death examination, describe how to assess for neurological absence of brain stem function
pupillary response to light
corneal reflex
oculocephalic reflex absent (dolls eye response)
oculovestibular reflex absent (cold caloric test)
gag and cough reglex
absent respiratory reflex (apnea test)
determination of brain death: how to perform the apnea test
100% FiO2 for 10 minutes
normalized PaCO2 (confirmed by ABG, T piece for 7-10 minutes, repeat ABG)
PaCO2 >60mmHg during test
absence spontaneous ventilation
who cannot declare brain death
transplant team
DCD s/p cardiac arrest: death anticipated within
1-2 hours after life support is withdrawn
warm ischemia time can be _______ v _________
controlled (ICU, decision to take off life support) versus uncontrolled
living organ donors: kidney and advantages
decreased cole ischemic time
less time on waiting list
kidney living organ donors: how is the surgery performed
laparoscopic or open
kidney living organ donors: selection of kidney from living donor
usually left side because it is easily accessible and longer vasculature
kidney living organ donors: anesthetic
GETT standard monitors, maintain UOP (mannitol, lasix 30m prior to removal), 10-20ml/kg/h NS
kidney living organ donors heparin
about 5000 units prior to clamping of renal artery. have protamine on hand but won’t probably use because apparently 5000u isn’t a big dose
living organ donors: partial liver for adults
sections 5,6,7,8 taken for adults and donor is left 1/3 of their liver. right side
living organ donors: partial liver for pedes
left side taken from donor, smaller, easier to retrieve
living donor: partial liver anesthetic technique and monitoring
monitoring (CVP, 2 PIV’s, art line)
+/- epidural (coags? taking out the liver rn..)
NGT
no N2O (bowel distention would make visualization difficult)
living donor: partial liver volume considerations
can either drop CVP with transaction (<5mmHg to minimize blood loss), can volume load before cross clamp, isovolumic hemodilution or cell saver can be possible. if not using hemodilution, limit fluids to not engorge liver
what is cross clamped in a liver transplant on a living donor
hepatic pedicle
organ preservation strategies
hypothermia (decrease metabolism)
preservative solutions
what is the benefit of preservative solutions for organ preservation strategies
maintains cellular integrity
prevent cellular swelling, vasospasm and build up of toxic metabolites
provides source of energy
organ preservation ex vivo
rapid cooling at 4 degrees celsius
preservative solution
what preservative solutions are utilized for intraabdominal orrgans versus heart
UW used for intraabdominal organs (has alot of K)
celsior/cardioplegia: heart
organs removed in this order in relation to its susceptibility of ischemia
heart, lung, liver, kidney
maximum organ preservation times: heart and lung
4-6h
maximum organ preservation times: liver
8-12h up to 24h (but 24h not popular)
maximum organ preservation times: pancreas
12-18 hours
maximum organ preservation times: kidney
24-36 hours
presentation of brain death donor in OR
hypotension (related to loss of vasomotor control)
decreased CO and SVR
decreased oxygenation (aspiration, atelectasis, pulmonary edema)
DI (destruction of HPA)
bradycardia (b/c loss of vagal motor nucleus, increased ICP)
still have visceral and somatic reflexes. will have reflex pressor response (pain.muscle twitching) and spinal somatic reflexes.
for this reason, give muscle relaxants, opioids, and volatile still
colloid or crystalloid for lung and pancreas?
colloid preferred
goals for preservation of organ function include
MAP 60-100 UOP .5-3ml/kg/hr HGB >10gm/dL glucose 120-180mg/dL CVP 5-10mmHg FiO2 <40% if tolerated to minimize effects of O2 toxicity if lung retrieval involved PEEP no more than 10cm H2O Vt 6-8 SaO2 >95% PaO2 >100mmHg core temp >35c
which pressors to consider during organ donation
1st line: dopamine
2nd line: vasopressin
how to treat bradycardia for a brain dead patient
resistant to atropine since there is no vasomotor control so you have to use direct acting agents
so use isoproterenol
how to treat DI for brain dead patient
including type of IVF
vasopressin or DDAVP
free water D5W .45%NS, fluid type based on hourly serum electrolytes. check every hour
donor anesthesia and methylprednisolone
can protect heart, kidneys, lungs from ischemic injury
donor anesthesia and PGE1
lung protection/retrieval ->membrane stabilization
donor anesthesia overview of care
standard monitors, aline, CVP, swan pressors and NG/BB PRBC's/FFP for HGB heparin mannitol/lasix long acting NDMR
donor anesthesia special considerations
confirm ETT placement with surgical team midline incision, neck to pubis sternal saw-drop lungs organs mobilized and dissected aorta cross clamped and ventilator turned off (and you can leave)
donor anesthesia special considerations heart lung procurement
continue to ventilate manually about 4 breaths per minute, not for abdominal organs
