Grand Rounds Recap 7.21.21
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R4 CASE FOLLOW-UP WITH DR. IRANKUNDA
Sulfonylurea toxicity
Sulfonylurea MOA: Stimulates insulin secretion from the pancreatic beta-cell via ATP-sensitive K-channels in the beta cell plasma membrane.
Common presentations: hypoglycemia from therapeutic use, overdose, or an acute ingestion in which the patient is not yet hypoglycemic but later develops recurrent hypoglycemia due to longer duration of action
Sulfonylurea toxicity precipitates neuroglycopenia, which can be diverse in its manifestations on exam.
Monotherapy with sulfonylurea is decreasing, but combined therapy is increasing, which can complicate diagnosis and presentation of toxicity.
Social determinant of health impact: Significant cost of some diabetic medications may preclude some patients from accessing these safer medications with lower risk profiles.
Treatment: Dextrose, Octreotide, charcoal if within 2 hour window with good mentation
Take Home Points:
Trust, but verify. When you have reported prehospital interventions, tests, and/or assessments, it is important to verify as able, for example with prehospital finger stick blood glucose.
Check your times, especially as it relates to critical resuscitations so that you can track expected improvement and intervene if the patient does not follow with your expected response (as with MTP).
Secure collateral information promptly, especially with patients who present with altered mental status, as it can guide what you perceive as normal or abnormal and determine future interventions.
R3 TAMING THE SRU: REFRACTORY VENTRICULAR FIBRILLATION WITH DR. WINSLOW
Refractory ventricular fibrillation (VF) is defined as ventricular fibrillation that persists after 3 shocks, 300 mg Amiodarone, 3 x 1 Epinephrine 1 mg. It must be differentiated from recurrent VF in which VF terminates after defibrillation, but then recurs.
Presumptive etiology: sympathetically driven electrical overstimulation ‘electrical storm’
At UC, our criteria for eCPR/ECMO include: age 16-75 years, presumed cardiac etiology, initial arrest rhythm of VT/VF, persistent VT/VF after 3 shocks, CPR within 5 minutes of arrest likely, LUCAS in place, no DNR, Amiodarone 300 mg IV/IO given (if available), never in asystole, no known contraindication to blood products or anticoagulation
Some additional treatment modalities under continued study:
Dual sequential defibrillation - multiple studies with somewhat mixed results and potential harm to device, questionable voltage actual delivered to patient
Esmolol - B1-selective adrenergic blocker with rapid onset, easily titratable; 500 mcg/kg bolus and infusion (0-100 mcg/kg/min)
Meta Analysis by Miralgia in AJEM in 2020 found that esmolol was associated with increased survival to discharge and increased survival with favorable neurologic outcomes
Stellate ganglion block provides sympathetic innervation to the heart so proposed use to limit electrical storm. However, this practice has little robust evidence to guide its practice.
Lidocaine - Na channel blocker, which shortens time to repolarization, decreases QT interval
Study by Kudenchuk et al in NEJM in 2016 found no significant difference in survival to hospital discharge between Amiodarone, Lidocaine, and saline placebo
Magnesium - often administered to patients in nontraumatic refractory VF arrest. Ultimately, it is unlikely to help and is not associated with increased survival, but it is also unlikely to harm
THE ART OF DECISION MAKING IN OUR DISORDERED WORLD: CYNEFIN FRAMEWORK WITH DR. BENOIT
Our disordered world is defined by: many variables, nonlinear interactions, minor changes that produce major consequences, constantly shifting dynamism, solutions that arise from circumstances, team that is greater than the sum of its parts, Department with History, inevitable evolution.
Cynefin framework - reproduced by Creative Commons -https://commons.wikimedia.org/wiki/File:Cynefin_as_of_1st_June_2014.png
Cynefin Framework first published in 2007 and initially applied to business world.
Predicated on assumptions that we are constantly trying to organize our world, following a progression from chaotic to complex to complicated to simple.
Patients can fit into the Cynefin paradigm as well.
Simple Context - These patients may be diagnosed based on pattern recognition, reliance on categorization. Management may involve protocolized treatment in which there are definite knowns, facts, best practices that exist with respect to care. Limitations include potential for micromanaging, oversimplification, incorrect classification, complacency. Example: pediatric patient with asthma exacerbation.
Complicated Context - These patients may require “expert diagnosis,” feature more subtle cause-and-effect though discoverable, known unknowns that can be addressed. In these situations, you want to analyze, consult experts and/or solicit multiple opinions, and rely on good practice, standards of care. Limited by entrained thinking of experts, overconfidence, viewpoints of non-experts may be excluded., egos colliding. Example: stable trauma patient
Complex Context - In these situations, no truly right answer may exist; the situation is constantly in flux and unpredictable; cause and effect may be clear in retrospect; and there are unknown unknowns. In these situations, we must probe and respond to change, increase interaction and discussion, encourage dissent and diversity of practice. Limitations include: tendency towards command and control which may limit sources of information, habitual thinking, desire for an accelerated resolution. Example: hypotensive medical patient.
Chaotic Context - Situations characterized by high turbulence and tension, pointless looking for cause and effect, many decisions to make with no time to think, unknowable. We need to broadcast command and control, act and respond, establish order and stability and teams to take action. Limitations include: hard to reign in command and control once you progress to complex context. Example: patient found down in the ED lobby, presumed psychiatric and now with no spontaneous respirations
Cliff between Simple and Chaotic - most common reason for chaos, often stems from mentality or concept that success breeds complacency. Ways to prevent this are to be paranoid, stay connected to spot change early, listen to your “line” workers. Afterwards, you start from the beginning, reevaluate everything. Limitations: failure to accept and reacting too late.
BICARBONATE ADMINISTRATION IN ACIDOSIS WITH DR. ZACHARIAS
What is the rationale for initiating sodium bicarbonate for patients with metabolic acidosis?
Acidemia induces cellular dysfunction and vasoplegia and sodium bicarbonate increases pH.
Enables vasopressors that fail in acidotic environments to act more effectively on cellular receptors.
However, this therapy remains controversial. The majority of studies assessing sodium bicarbonate’s utility have been retrospective or observational in nature, others have been animal-based. Reluctance to sodium bicarbonate is often centered around potential side effects of worsening acidification secondary to carbon dioxide accumulation and hypocalcemia and absence of cardiovascular effects in studies.
Counterpoints:
Sodium bicarbonate does not increase pCO2, but rather increase iCO2 thus increasing intracellular acidosis.
Theoretical concern that cells will produce more lactic acid in the process of downregulating glycolysis and worsen acidosis, but this is theoretical and has not been borne out in studies, even if it makes sense.
Paradoxically, vasodilation induced by acidosis at the capillary level is actually intended to be beneficial as it promotes oxygen delivery. Lactic acid may increase in this situation but it represents reperfusion.
Take home points:
Consider earlier initiation of Vasopressin and Bicarbonate gtts since they take longer to procure in the ICU compared to the ED
Sodium bicarbonate does not necessarily contribute to acidosis. Intracellular CO2 does increase when NaHCO3 is administered, but this often leads to intracellular pH changes rather than extracellular changes. Excess pCO2 is expired.
BICAR-ICU multicenter RCT (Lancet, 2018) assigned patients admitted to ICU with severe acidemia and total SOFA score of 4 or more to no NaHCO3 or to IV NaHCO3 infusion. Notable finding: decreased primary composite outcome and 28-day mortality in a-priori defined stratum of patients with acute kidney injury.
Negative effects of hypernatremia should not deter you if NaHCO3 is warranted as they are typically transient.
TRAUMA ADMIT-TRANSFER-DISCHARGE WITH DR. ADAN
Trauma centers are not as abundant as you might imagine, so you will inevitably see some traum in the community and most certainly during residency.
Case 1: Middle aged male with facial pain after he was rear-ended in an MVC and hit his face on a steering wheel. VS stable. Exam with R periorbital pain, ecchymosis, and a small laceration. Work up with CTH and CT max/face with no acute findings. Okay to discharge home.
Case 2: Middle aged female with rib pain after she was involved as the restrained driver in an MVC, rear-ended another car. VS stable. Exam with left lower rib pain, diffuse abdominal pain. Work up with CT scan, CXR, urine pregnancy, some labs. Finding with grade III spleen laceration, mild to moderate hemoperitoneum. Transfer to trauma center.
Case 3: Elderly female with facial injury after she fell on the sidewalk, hit the left side of face on landscaping. Stable VS. Exam with large left periorbital hematoma with mild proptosis. Concern for retrobulbar hematoma. Performed a lateral canthotomy (1. Anesthetize with 1% lido with epi 2. Hemostat to lateral canthus and devascularize tissue 3. Cut inferior and then the superior canthus). Don’t worry about the mess you cause to the outside of the eye, just try not to injury the globe of the eye in the process. Transfer for specialist services.
Case 4: Young female with right ear injury sustained from a dog bite. VS stable. Exam with complex laceration to the helix and posterior right ear. Case resolution - primary repair with bolster, approximated well, arranged for outpatient follow-up with specialists. Augmentin to cover dog oral flora, though Cipro plus Flagyl may also be an option.
Case 5: Pediatric male with neck injury, stabbed in the neck by a pick comb. VS stable. Exam with large metal tine sticking out of his neck, no bruit, expanding hematoma.
Take Home Points:
Mindset # 1: Don’t let your guard down, even though many trauma patients you see in the community will be fine. Delayed presentation should not necessarily change the management that you would have otherwise pursued.
Mindset # 2: Do what needs to be done whether it’s a lateral canthotomy, escharotomy, thoracotomy, etc.
Mindset # 3: Take advantage of the resources you have around you (eg, follow up with attending specialists, PCP)
Mindset # 4: Don’t be a hero. No reason to do something that you don’t have back up for and which has another easy solution.
QUARTERYLY SIMULATION: Lower GI Bleed WITH DR. LAFOLLETTE
Lower GI Bleed (LGIB) accounts for 20% of all GI bleeds and 75-90% resolve with no need for invasive intervention. However when LGIB present unstable, have underlying coagulopathy or dynamically bleed during your care, it is important to have diagnostics and therapeutics ready.
Etiologies of LGIB
Diverticulosis (20% confirmed, up to 40% suspected)
Cancer (10-15%, varied presentation)
IBD
Vascular malformations
Ischemic colitis (tend to have lower transfusion requirements and remarkably have less recurrences)
Hemorrhoids (painless, internal, rarely significant) (Adegboyega 2020)
CT angiography for LGIB
CTA localizes bleeding in ~38% of cases of LGIB (Fuererstein 2016)
CTA + bleeds are 50-90% right sided, 60% diverticular bleeds are left sided
Diverticular bleeds are likely to recur (~30-50%) and are more likely to need intervention if they do
In CTA positive LGIB, older patients and those with active evidence of bleeding are more likely to undergo IR than surgery (Pannatier 2019)
In summary - in hemodynamically significant LGIB, CTA is a helpful diagnostic that have help localize and facilitate interventional radiology-coiling of active extravasation. Also consider reversal when appropriate and a balanced product resuscitation.
