Grand Rounds Recap 3.20.19
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navigating frozen waters- brain death in the era of therapeutic hypothermia WITH DR. bonomo
Brain Death and Organ Transplantation
Brain Death is the irreversible loss of neurologic function, as defined by clinical criteria or adjunctive testing
Clinical criteria include loss of all brain-stem and cerebral function in the absence of factors that could confound the subsequent examination (shock, hypothermia, electrolyte derangement, paralysis, neurologically depressing agents)
The Dead Donor Rule specifies that organ donation must not cause death of the donor.
Brain death is an indicator of legal death in some jurisdictions, allowing for organ donation of life-sustaining organs in those affected.
History
Denise Darvall became the first person to become a donor for a heart transplant after being struck in a motor vehicle accident in 1967
She had some preserved brainstem reflexes before donation, so was not brain dead by modern definitions
The United States had the technology to perform a heart transplant at that time, but could not due to the dead donor rule
It wasn’t until 1981 that the United States adopted the Uniform Determination of Death, which states that a patient with 1) irreversible cessation of circulatory and respiratory function or 2) irreversible loss of function of the entire brain, including the brain stem, is dead.
This definition is different than the definition of brain death, as it is possible to have cessation of circulatory and respiratory function on life-support without evidence of brain death.
Therapeutic Hypothermia
This practice provides a challenging confounder in the diagnosis of brain death
Patients with therapeutic hypothermia have unpredictable half lives of drugs that depress neurologic function
Accessory testing in the determination of brain death
Accessory testing can help aid in the diagnosis of brain death, but must be used in conjunction with clinical exam
Cerebral angiography
There is no gold standard for the amount of force to apply to inject contrast
Cerebral scintigraphy
There is institutional standard for the time to re-image in nuclear medicine testing for nuclear studies for brain perfusion
CT angiography
CT angiography was found to only be 85% sensitive in the diagnosis of brain death
CT angiography can be less accurate in the case of depressed ejection fraction
The Future
Moving forward, we must consider how increasing medical complexity and improved medical technology will affect determination of brain death.
We must also consider the implications of the dead donor rule on the future of organ transplantation.
R4 Case Follow-up WITH DR. harrison
PEA vs. Hypotensive Bradycardia
These can be difficult to distinguish, as palpable pulses can be difficult to detect in profoundly bradycardic rhythms, especially in the prehospital setting
This has lead to study of “pseudo-PEA”, or patient’s falsely thought to be in cardiac arrest due to absence of a palpable pulse
Palpation of a pulse can be difficult due to a number of confounders, including body habitus, peripheral artery disease, and profound shock.
PEA prognostication
Narrow complex causes
Tamponade
Tension pneumothorax
PE
Acute MI
These are more likely reversible
Wide complex causes
Metabolic problems (hyperkalemia, sodium channel toxicity)
Agonal rhythm
Acute MI (again)
Narrow QRS complex and tachycardia have been found to be associated with higher incidence of ROSC
Treatment
Epinephrine vs. Atropine
Atropine works by eliminating parasympathetic activity only, but fails if bradycardia is caused below the AV node
Epinephrine works throughout the myocardium (SA node, AV node, atria, ventricles)
For this reason, epinephrine is more versatile than atropine in undifferentiated bradycardic peri-arrest
Transcutaneous Pacing (TCP)
Taming the SRU: r3 case follow-up WITH DR. Nagle
AORTIC DISSECTION
Background
Aortic dissection is dissection through the aortic intima, which leads to blood leaking into the media
This occurs in 3.5/100000 patients per year
Even when optimized, mortality is 30%
There is a 1-2% mortality for every hour of treatment delay
Patients have a 38% misdiagnosis rate
Risk factors include bicuspid valve, aortic coarctation, male gender
Diagnosis
Up to 20% of patients with aortic dissection present with no chest pain
Institute of the Registry of Aortic Dissection is a retrospective body that studies those with aortic dissection
Acute Dissection Detection Risk Score (ADD-RS)
ACEP clinical policy in 2015 states that d-dimer alone cannot be used to rule out dissection, but does not comment on d-dimer plus the ADD-RS score
Imaging
CTA has been shown to be equivalent to MRI and TTE in detecting dissection
Treatment
Type A dissection (ascending dissection) require surgical and medical treatment
Type B dissection (descending dissection) require medical treatment
Medical treatment
Control pain (ex. fentanyl) to decrease endogenous catecholamines
Control heart rate and blood pressure to limit aortic stress (target HR of 60 and SBP of <100)
Utilize the right arm or arterial line for blood pressure management because the left circulatory system is more commonly affected by dissection
R4 Case Follow-up WITH DR. summers
PRES Syndrome
Background
The cause is controversial, but thought to be due to impaired cerebral autoregulation leading to cerebral perfusion deficits in patients with hypertension
PRES is a clinicoradiological diagnosis of HA, AMS, seizures, or vision changes in those hypertension and with posterior leukoencephalopathy on imaging
Making the diagnosis
70% with have seizure, 50% will have impaired consciousness, and 50% will have headache on initial presentation before confirming diagnosis
Imaging will show focal symmetric edema in the watershed zones
In 90% of diagnosis, the posterior brain is involved
Common risk factors include female gender, hypertension, and use of chemotherapy agents
Reversible?
This was called reversible because in the initial study in 1988, all 15 of the patients recovered
Treatment
The mainstay of treatment is supportive
Blood pressure control
No more than 25% reduction over the first 6 hours
There is no data on which antihypertensive to use
Withdraw any toxic agents
Treat seizures with standard practice
Use of steroids is controversial, and is not correlated with improved clinical outcomes
Wellness curriculum: Resilience WITH Dr. leenellett
Physician Burnout
Up to 50% of medical students and 70% of residents report burnout
Emergency medicine has one of the highest rates of burnout
This is different than stress, as stress will improve with recovery time
Burnout leads to depersonalization and a lack of enjoyment derived from work
Why does this matter?
Physicans with burnout have more medical mistakes
They also have increased rates of substance abuse, suicide, and depression
How can residents develop wellness?
Pursuit and achievement of goals (purpose)
Building competence in their specialty (mastery)
Strong social relatednes, sleep, and time away from work can help develop wellness
Fixed vs Growth Mindset
In a fixed mindset, you believe people are born with a certain amount of ability and talent, and most work to show these abilities
This leads to fear of failure and a focus on appearing an expert
In a growth mindset, you believe that your basic qualities can be cultivated through effort, strategy, and help from others
This causes a focus on development and learning rather than appearing an expert
Resilience
Resilience is the process of shaping the way you adapt to challenges and failures
How do we do this?
Identify who you are and what gives you meaning in your work
Identify three things that you are grateful for and thankful for each day
Form social network as this leads to the dynamic spread of happiness
Take care of your basic needs (eat, drink, sleep)
Recognize when you are feeling stress, and reach out for help
