Grand Rounds Recap 2.16.2022
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EMS GRAND ROUNDS: CARDIAC ARREST AND TERMINATION OF RESUSCITATION WITH DR. LI
Is it better to stay and play or transport?
Current evidence does not support the transport of patients undergoing CPR, though this still may occur or may even be preferable for a number of reasons, including scene safety.
This is supported by research by Grunau et al demonstrating improved survival to hospital discharge as well as favorable neurologic outcomes with on scene resuscitation versus intra-arrest transport.
The above findings likely related to the ability to provide quality CPR administered during transport with increased potential for poor chest compressions and interruptions in compressions. However, these studies of CPR quality were often performed prior to widespread use of mechanical compression devices like the LUCAS.
What is the best airway in cardiac arrest?
Prehospital Cardiac Arrest Airway Management
Based on the skill of the clinician and available resources, BVM, SGA, ETI may be considered as airway management strategies in Out-of-Hospital Cardiac Arrest (OHCA)
Airway management should not interfere with other key resuscitation interventions such as high-quality chest compressions, rapid defibrillation, and treatment of reversible causes of arrest.
EMS clinicians should take measures to avoid hyperventilation during cardiac arrest resuscitation
Where available for clinician use, capnography should be used to guide ventilation and chest compressions, confirm and monitor advanced airway placement, identify ROSC, and assist in decision to terminate resuscitation.
Comparison of different airway management strategies in OHCA
BVM v. SGA - no RCTs in adult OHCA, but recent reviews and meta-analysis have found no difference in survival to hospital discharge, 30-day survival, or neurologic function
BVM v. ETT - Single RCT performed in a physician-led EMS system in Europe with 98% ETI success. Results demonstrated non-inferiority of BVM for 28-day survival with favorable neurologic outcomes, but there were more complications with BVM, including difficult airway management, airway failure, and regurgitation of gastric contents.
SGA v. ETT - There are more studies comparing SGA v. ETT.
One RCT in 2018 looked at ETT v. Igel with a crossover component. Patients with SGA (King LT) had better survival at 72 hours (primary outcome),ROSC, hospital survival, and favorable neurologic outcome comparted to those with ETI (SGA 90.3% success; ETI 51.6% success)
The Airways-2 Trial in 2018 was an RCT of SGA v. ETT in OHCA and found no statistically significant difference between SGA and ETT with respect to favorable neurologic outcome (primary outcome). SGA had slightly higher incidence of regurgitation and aspiration, but also had a higher rate of ventilatory success.
Conclusion: iGels or other newer supraglottic airways are great in the field and have comparable and, in some studies, better survival. No need to switch out in the field.
Termination of resuscitation prior to 30 minutes
30-minutes is often thought of as the standard time for resuscitation across EMS agencies, but it is not. There is wide variations.
Why might providers terminate resuscitation earlier than 30 minutes?
Difficult to provide high quality CPR during transport
Emergency response is not benign. Almost 60% of ambulance crashes occur while responding to a medical emergency.
Resource utilization of an ambulance while transporting a patient means it is not available to respond to another medical emergency.
Evidence underlying relationship between duration of resuscitation and outcomes in OHCA
Study by Goto et al in 2016 of 17k OHCA found that patients with favorable neurologic outcomes and survival varied by rhythm with VF/pulseless VT with significantly higher survival and favorable neurologic outcomes. At 20 minutes, one-month survival was 4.6% and a good neurologic outcome was 1.9% whereas at 30 minutes, one month survival was 0.8% and good neurologic outcomes was 0.4%. In most medical literature, futility is defined by <1%.
In another study by Grunau et al in 2016 comparing those with shockable and non-shockable rhythms, survival to hospital discharge among fell below 1% at 34 minutes on average for the entire cohort and extended to 40 minutes for those with a shockable rhythm. This pattern was also noted when evaluating good neurologic outcomes. Those with shockable rhythms were noted to have good outcomes even after 35 minutes.
How to interpret sudden increase in end-tidal CO2?
Uses of End Tidal CO2: correlates with cardiac output and provides an indication of tissue perfusion, confirmation of airway placement and ventilation monitoring, help in optimizing compressions, identifying potential ROSC, potential rose in determining prognosis, assist in determination of TOR
An abrupt and sustained increase in ETCO2 could be a marker for ROSC. It has been shown to be specific but not sensitive for ROSC.
No change in ETCO2 or absolute threshold can definitively predict ROSC or neuro intact survival.
A sudden drop could signal re-arrest or a dislodged airway.
A meta-analysis found that ETCO2 < 10 after 20 minutes of resuscitation had a 0.5% chance of ROSC..
Regardless, ETCO2 should not be a the sole factor in decision for TOR
When do you terminate in traumatic arrest?
Consider immediate interventions in traumatic arrest, which may include bilateral needle decompression +/- ventilation of the chest to relieve tension pneumothorax, fluid or product resuscitation if available, and tourniquet or binder for massive hemorrhage.
If patient remains in asystole or pea < 40, then contact medical control for TOR
If patient is in PEA > 40, then fluid resuscitate, consider repeat decompression, transport to trauma center
If patient is in vfib/vtach, defibrillate per protocol, fluid resuscitate, consider repeat needle decompression, and transport to nearest trauma center
Family presence during resuscitation in the pre-hospital setting
Family presence may lead to decreased PTSD, anxiety, and depression among EMS providers with concomitant medicolegal effects, change in team stress, or survival.
Qualitative evaluation found that family members perceived better communication, had a more realistic perception of the severity of patient illness, and felt relief in witnessing some heroic actions.
IMPLEMENTATION SCIENCE WITH DR. FREIERMUTH
The time from research ideation to scientific discovery and standard practice is long. Time from discovery to integration into standard practice is estimated to be ~ 17 years according to IOM 2001 report.
We have seen this in the treatment of stroke with tPA. NINDS trial published in 1995, and ACEP Clinical Policy on the use of IV tPA in ischemic stroke published in 2012.
Similarly, Buprenorphine was approved for use to treat Opioid Use Disorder in 2002, and Trends in Buprenorphine Use in US EDs published in 2020.
Implementation science is the study of methods and strategies to facilitate uptake of evidence-based practice and research into regular use or, in short, the transition from knowing to doing.
Common barriers: understanding by those served by intervention and those helping to facilitate intervention, generalizability of intervention, feasibility of intervention, evaluating the impact of the intervention and communicating it to important stakeholders and those served, communicating the importance to stakeholders as well as populations served.
Navigating issues in real world v. research implementation
Understand the environment and anticipate barriers
Different types of frameworks may be helpful for shaping a comprehensive approach, but there are a ton (~73) (ie, theory of diffusion, knowledge-to-action model, absorptive capacity, etc). These can be further grouped into process frameworks, determinant frameworks, classic theories, implementation theories, and evaluation frameworks.
As you get started:
Engage all necessary stakeholders
Define intended intervention - what is key and what can be modified
Encourage continuous engagement and refinement with change tracking
Determine your outcomes - What you will measure at different levels? individual outcomes (ie, satisfaction), systems outcomes (ie, efficiency, safety, equity, timeliness), implementation outcomes (ie, acceptability, adherence, costs, sustainability)
How will you measure? Where will you collect the data and what are your pre-set cutoff’s for data collection (power needed to address question)
Ethical considerations - What are the ethical considerations? Need for IRB approval?
Sharing your findings
Standards for Reporting Implementation Studies (StaRI) - 27 pt checklist detailing implementation strategy, theory and intervention employed, hypothesis, fidelity and adaptability of intervention, and context definition.
R1 CLINICAL DIAGNOSTICS AND MANAGEMENT: HEMOPHILIAS WITH DR. GRISOLI
Hemophilia A - Factor VIII deficiency (more common, X-linked, 1/5000 males)
Hemophilia B - Factor IX deficiency (X-linked, 1/15,000-1/30,000 males)
Acquired hemophilia affects ¼ milion and usually involves development of an autoantibody to factor VIII. This is associated with SLE, malignancy, and pregnancy.
Severity grading
Mild: Prolonged bleeding observed with major trauma or surgery; Factor activity 5%-40%
Moderate: Severe bleeding with minor trauma or surgery, occasionally will have spontaneous bleeding; Factor activity 1%-5%
Severe: Frequent spontaneous bleeding; Factor activity < 1%
Clinical presentation
Clinical presentation is often indistinguishable, though Hemophilia B is typically milder than Hemophilia A. May be diagnosed late or by genetic screening with family history.
Consider a new diagnosis in a male with persistent oozing from umbilical stump, perinatal bleeding complications, refusal to move an extremity or bear weight, suspected septic arthritis, which can mimic hemarthrosis.
Diagnosis
Relies on high clinical suspicion. Should refer to hematology or consult hematology if high enough suspicion.
aPTT used to screen, though may be normal in pts with mild disease
Definitive test will be with specific factor levels
Evaluation and management for suspected hemarthrosis v. septic arthritis
Avoid NSAIDS
MRI is gold standard with respect to imaging
Arthrocentesis after discussion with Orthopedic and Hematology consultants
Empiric antibiotics for septic arthritis while awaiting factor level
For patients with established hemophilia and bleeding:
Resuscitate and control hemorrhage
Collect key history regarding home factor replacement therapy and presence of factor inhibitors
Finally, remember early consult Hematology and initiation of factor replacement
General principles of management of bleeding in hemophilia
Factors products are dosed to achieve a target level
“Life-threatening bleeds” (ie, ICH, GI bleed, etc) are dosed to 100%
“Severe/serious” bleeds are dosed to 50%
If unknown, assume patient’s baseline factor level is 0%
Attempt to administer patient’s usual factor product when possible, but prompt administration of factor is more important than waiting for specific brand of clotting factor
Workup of patients with suspected hemarthrosis
Ankle is more commonly affected joint in children
Knees, elbows, and ankles more commonly affected in adolescents and adults
Routine hemarthrosis does not require imaging, though hip effusions may be a special case
Consult orthopedics
Disposition
Some of these patients may be able to go home, but decision should be made with patient and in concert with Hematology based on whether they feel better, are able to bear weight.
Consider ice packs and analgesia (avoiding NSAIDS!), what their follow up will be, and whether they have enough factor at home.
Management of head trauma in patients with Hemophilia
Send factor level prior to repletion
For CNS bleeding, replete factor to 100%
For Hemophilia A: 50 U/kg Factor VIII
For Hemophilia B: 100 U/kg Factor IX
When managing Hemophilia in the community:
Consider Cryoprecipitate equivalent to 80 U Factor VIII for Hemophilia A
Consider FFP equivalent to 0.5 U/ml Factor IX, though concern for volume overload at therapeutic dosing given amount that would need to be administered (For example: 30 kg person with need for 100 U/kg would need 3 L of FFP)
Tetanus shots and any other IM shots should wait for factor replacement
When in doubt, phone a friend
Summary points:
Consider hemophilia as a new diagnosis, especially in a pediatric population
Remember early Hematology consult and/or call to the Hemophilia Treatment Center
Initiate prompt, empiric treatment if concern for life-threatening or serious hemorrhage.
Empirically dose factor product assuming a baseline activity of 0%
Avoid arthrocentesis in routine hemarthrosis.
More information in this post on Taming the SRU
R2 CPC: DAPSONE-INDUCED METHEMOGLOBINEMIA WITH DRS. FINNEY AND JARRELL
Methemoglobin is a form of hemoglobin that has been oxidized, changing heme iron from ferrous Fe2+ to ferric Fe3+
Methemoglobin cannot bind oxygen, so cannot deliver oxygen to tissues. Furthermore, ferric heme also causes remaining normal ferrous heme to have increased O2 affinity with a subsequent left shift and further decrease of oxygen delivery.
Methemoglobinemia is diagnosed if the level is >5%. Patients typically become symptomatic at 10%. A level >30-40% is considered life-threatening
Presentation
Symptoms may include mild cyanosis, dyspnea or nonspecific symptoms (headache, lightheadedness, fatigue, irritability, lethargy) to shock, severe respiratory depression or neuro deterioration (coma, seizures) d/t tissue hypoxia
Symptom severity correlates with methemoglobin level
Signs of toxicity include pale, gray, or blue colored skin, lips, or nail beds in presence of normal PaO2, hypoxia that doesn’t improve with supplemental O2, and discoloration of blood (dark red, chocolate or brownish to blue)
Suspect if unexplained cyanosis, hypoxia that does not resolve with O2
Evaluation includes co-oximetry and a blood gas (ABG preferred). Routine pulse oximetry cannot detect because it absorbs light at the pulse oximeter’s two wavelengths, leading to an error in estimating percentages of reduced and oxyhemoglobins.
Causes
Medications: topical anesthetics, Dapsone, antimalarials, inhaled nitric oxide, nitrites/nitrate agents
Foods: Carrots, beetroot, radishes, mushrooms
Toxins: Antifreeze
Congenital causes
Treatment for methemoglobinemia
For patients with Methemoglobinemia levels >20-30%, treat with Methylene Blue per our DPIC.
Works quickly, reducing by < 10% within 10-60 minutes
Avoid Methylene Blue if patient has G6PD deficiency or if they are taking serotonergic meds as it can precipitate serotonin syndrome). Use ascorbic acid instead.
In severe disease, exchange transfusions and hyperbaric oxygen have been used, according to certain case reports
