UMEM Educational Pearls

This Canadian study looked at the safety of paramedics using the modified Canadian C-Spine Rule to determine which pre-hospital blunt trauma patients required immobilization. These were MVC and fall patients predominately. Bottom line: appropriately trained paramedics can use the modified Canadian C-Spine rule to clinically clear cervical spines in the field. 

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Background:
Despite a lack of reliable evidence, sodium bicarbonate (SB) still appears in various protocols as a potential therapy for patients in cardiac arrest. Local EMS protocols also endorse the use of (SB) in specific scenarios such as: tricyclic overdose and hyperkalemia. EMS systems struggle to articulate best practices with respect to indications for SB administration. 

Patients/methods:
Study authors conducted a scoping review of existing literature. The review included in hospital and out of hospital patients with cardiac arrest. Despite multiple studies looking at this question, a total of 12 were included in the final analysis. Criteria for inclusion were as follows: RCT or observational studies looking at patients aged 18 or older who experienced a cardiac arrest. Important outcome metrics incorporated: neurological recovery and survival to discharge. 

Results:
The retrospective review failed to demonstrate a reliable association between survival and administration of sodium bicarbonate. Despite significant limitations (different study populations, retrospective designs), there remains insufficient evidence to consider routine administration of bicarb in the setting of cardiac arrest. 

Bottom line:
Empiric administration of SB is not linked to a reliable benefit. SB may be considered for specific indications (tricyclic overdose, hyperkalemia) but is unlikely to improve outcomes such as neurologic recovery or hospital discharge. EMS systems should avoid recommending routine SB administration for patients with out of hospital cardiac arrest.

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Title: Albumin Versus Balanced Crystalloid for the Early Resuscitation of Sepsis: An Open Parallel-Group Randomized Feasibility Trial— The ABC-Sepsis Trial

Settings: 15 ED in the United Kingdom. This study is a feasibility study but it looked at mortality as a primary outcome.
Participants: 
•    Patients with Sepsis, with their National Early Warning Score (NEWS) ? 5 (These patients have estimated mortality of 20%). IV fluid resuscitation needs to be within 1 hour of assessment.
•    300 Patients were randomized to receive balanced crystalloids or 5% human albumin solution (HAS) only, within 6 hours of randomization.
Outcome measurement: 30-day mortality, Hospital length of stay (HLOS)
Study Results:
•    The median time for receiving IV fluid from randomization was 41 minutes (HAS) vs. 36 minutes (crystalloids).
•    Total volume of IV fluid per Kg  in first 6 hours 14.5 ml/kg  (HAS) vs. 18.8 ml/kg (crystalloids).
•    Other interventions (vasopressor, Renal replacement therapy, invasive ventilation) were similar.
•    Complications (AKI, pulmonary edema, allergy) were lower for Crystalloids group
•    Median hospital LOS = 6 days for both groups.
•    90-day mortality: 31 (21.1%) (HAS) vs. 22 (14.8%) (Crystalloids), OR 1.54 (95% 0.8-2.8)
Discussion:
•    Total volumes for resuscitation in the first 6 hours was 750 ml (HAS) and 1250 ml (crystalloids). This signified a trend toward lower total volume of resuscitation (remember that 30 ml/kg recommendation)
•    The 2024 guidelines from Chest (REF 2) suggested that: “In Critically ill adult patients (excluding patients with thermal injuries and ARDS), intravenous albumin is not suggested for first line volume replacement or to increase serum albumin levels. Therefore, we should not give patients (except for cirrhosis or spontaneous bacterial peritonitis) albumin just to reduce the volume of fluid.
•    The authors suggested that even a definitive trial in the future will not be able to demonstrate a significant benefit of using 5% albumin.
Conclusion: 
There is lower mortality (numerical but not statistically) among the group with balanced crystalloids.

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The Lipliner Sign is causing a lot of buzz within the ultrasound community, particularly concerning its implications for focused assessment with sonography for trauma (FAST) exams. This artifact arises from postprocessing techniques that enhance organ visualization but can inadvertently create a hypoechoic line that resembles free fluid leading to false positive exams. 

Key points to note: 

Nature of the Artifact: The Lipliner Sign manifests as a linear, hypoechoic outline around an organ, misleading clinicians into thinking there's free fluid present. 

Differentiation: As mentioned in this case report, free fluid typically appears wedge-shaped and tapers as it moves into dependent areas, while the Lipliner Sign is more linear and closely follows the organ's contour. 

Manufacturer Variability: This artifact can be observed across different ultrasound machine manufacturers. 

Clinical Implications: Misinterpretation of the Lipliner Sign could lead to unnecessary interventions or misdiagnoses in trauma settings, underscoring the importance of thorough training and awareness of potential artifacts.

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This meta analysis looked for studies involving community EMS (CEMS) interventions trying to reduce falls. The authors found: 

“CEMS fall prevention interventions reduced all-cause and fall-related emergency department encounters, subsequent falls and EMS calls for lift assist. These interventions also improved patient health-related quality of life, independence with activities of daily living, and secondary health outcomes.”

Further, prospective work needs to be done to look at this on a larger scale. We know falls in elderly patients lead to significant morbidity and mortality. This could be one way  to improve fall mortality.

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A northeast university was recently in the news when several members of the lacrosse team were hospitalized with rhabdomyolysis. 9 of 50 players who participated in the workout required hospitalization. This occurred after a single intense 45-minute workout led by an alum and recent graduate of the Navy Seal training program.

It was surprising to many that young, fit, athletes would be so affected from a single workout.

Nontraumatic exertional rhabdomyolysis occurs following intense physical activity especially in untrained individuals or those unaccustomed to the particular activity (for example a group of runners performing an intense HIIT workout).

Prolonged strenuous activity can result in rhabdomyolysis even in trained individuals in the absence of known risk factors or prior history.

Increased risk when natural cooling mechanisms are affected such as when the individual is taking medications with anticholinergic properties, or the individual is wearing heavy military gear or football equipment.

Increased risk with sickle cell trait.

Increased risk when that activity is performed in environments of severe heat and humidity.

Exercise routines that have a heavy eccentric focus increases risk of rhabdomyolysis.

            An Eccentric exercise involves slow lengthening of muscles under load 

Examples:   the lowering phase of a barbell while performing a bench press or the downward phase of a pull up

Helpful kinetics:

Following the exertional event, the serum CK will rise within 2-12 hours, reaching its maximum in 1-3 days.

CK has a serum half-life of approximately 36 hours. 

CK levels decrease at approximately 40% per day.

• Did you know that emergency physicians spend nearly 1/3 of their handoff time responding to interruptions?
• EPs are interrupted around 7-11 times during handoffs, accounting for 11% of the total adverse events, a third of which are considered preventable.
• This study examined the number of interruptions and perception of collaboration in three different physical spaces in the same ED: an open workstation, an enclosed workstation, and a semi-open workstation (see photos and blueprints below).
• Most EDs have open workstations as they are thought to optimize visibility and opportunities for collaboration among team members of all levels.
• EPs conducting handoffs in open workstations experienced more interruptions (patient care-related or not) as compared to those in the enclosed workstations. 
• Investigators found that enclosure of the physicians’ workstation can decrease the number of times physicians are interrupted during critical tasks like handoffs, therefore decreasing the risk of errors and adverse events.
• EPs perceived a high degree of collaboration with colleagues in the enclosed workstation during handoff and felt less interrupted.
• While the number of documented handoff interruptions in the semi-open plan were lower than the open workstation, EPs still perceived interruptions as frequent. 
• While there are clear benefits of the open workstation in the ED, it may be worth considering a different venue, specifically for handoffs, such as a “No Interruptions Zone” (NIZ) to decrease the perceived and actual frequency of interruptions, while also improving the sense of collaboration between team members during the handoff process.

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Some points from this narrative review:

• much of the existing literature is based on animal models or small human studies
• successful ventilations per compression pause (“synchronous" ventilation, 30:2, without advanced airway) is unsurprisingly important for neurologically intact survival
• no clear difference in outcomes between “synchronous” vs. “asynchronous” (insufflation without pause in CPR) ventilation
• RR below 6 breaths per min were associated with decreased ROSC, whereas faster RR were not associated with worse outcomes (however, be cautious of breathstacking in pts with asthma/COPD)
• chest rise can be detected with TVs as low as 180 mL which is likely not sufficient for CPR
• the benefit of larger tidal volumes (improved oxygenation, less hypercapnia) may outweigh the perceived costs (gastric insufflation, impact on venous return/CO)

Take home pearls:

• use 2-person BVM to ensure adequate TVs and aim for more than just minimal chest rise
• err on the side of moderately larger TVs rather than smaller and moderately faster RR rather than slower (but be cautious in pts with asthma/COPD)

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The FDA approved two cell-based gene therapies for the treatment of Sickle Cell Disease in December, 2023.  These therapies show potential to dramatically improve the outcomes and quality of life for patients with SCD. You may soon encounter patients who received one of these treatments in the ER, so here is an intro to what they are:

Casgevy is an FDA-approved gene therapy for sickle cell disease in patients 12 and older with recurrent vaso-occlusive crises. It uses CRISPR/Cas9 genome editing to modify blood stem cells, increasing fetal hemoglobin (HbF) production, which prevents red blood cell sickling.

Lyfgenia, also a gene therapy for sickle cell disease, uses a lentiviral vector to modify stem cells to produce HbAT87Q, a hemoglobin that reduces sickling. Both therapies involve modifying the patient's own stem cells, followed by myeloablative chemotherapy, and are given as a single infusion. 

Long-term safety and effectiveness is still being studied.  More to come in the future!

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This study attempts to validate the use of the Geriatric Fever Score to predict 30 day mortality in patients over age 65 presenting to an emergency department with fever. 
The Geriatric Fever Score uses: leukocytosis, severe coma,  and thrombocytopenia. One point is award for each abnormality. 
Not surprisingly, mortality went up with the higher the score (33%, 42% and 57% for 0,1,2 points)

For me, I’m not discharging anyone with severe coma, leukocytosis or thrombocytopenia in this patient population therefore I’m not sure this scale has much utility for the practicing emergency physician.

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The term Latinx gained some popularity as a gender neutral/noncomforming descriptor for people of Hispanic descent.  However, in some national surveys among Hispanic populations in the US, only a small percent were even aware of the term or what it meant.

This study looked at patients at several hospitals with large Hispanic populations.  Again a minority of respondents had even heard of the term.  In those that had heard of it, there were a wide range of self reports interpretations of what exactly it means. 

In the end, we come back to the same conclusion: if you want to know how your patient wants to be addressed, just ask.  Don't assume

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This study looked at the success rates of femoral vs proximal tibial IOs in the prehospital setting.  Over a 9 year period, there were 163 pediatric patients who received either a tibial or femoral IO.  Femoral IOs were introduced into the EMS protocol in this study area in 2015 as a location option and were the recommended site starting in 2019.  The success rate of femoral IO placement was 89% and for proximal tibial sites was 84.7%.  After further data analysis the study found an adjusted odds ratio of 2 for successful IO placement in the distal femur compared to the proximal tibia.  The complication rates for both sites were similar.  

Bottom line: This study suggests that the distal femur is a reasonable site for IO access in the pediatric population.

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The use of seizure prophylaxes in moderate to severe head injury has been recommended for 7 days post-injury. In general, levetiracetam is used for seizure prophylaxes in this group of patients. This study looked retrospectively at high (over 500 mg BID) vs. low (500 mg bid) dosing and found there was no difference in seizure events in either group.  Overall 6% of patients had a seizure in this seven day window even with medication given.

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This study looks at the efficacy of ketamine vs. midazolam for the prehospital sedation of acutely agitated patients, examining the need for repeat sedation (by EMS or in the ED), adverse events and length of stay.

A greater number of patients required repeat sedation within 90 minutes with initial ketamine dosing compared to midazolam. There was no difference in patients receiving repeat sedation within 20 minutes between the two groups.

There were no significant differences in time to repeat sedation, total sedation doses (by EMS or in the ED), use of bag valve mask ventilation or intubation, use of physical restraints, admission location/level of care, or length of stay in the Emergency Department (ED), hospital, or Intensive Care Unit.

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I wanted to send out two websites curated in part by UMEM current and past faculty/residents/fellows which have a wealth of critical care lectures and resources:

• The Maryland Critical Care Project is managed by the current UMMC CCM fellows and has one of the best collections of CC lectures out there with some big names in CC (it is also founded by several UMEM faculty/alumni). Check out their core content series.
• STCMTCC.com is a website curated by STC CC faculty with a wealth of trauma-oriented education (and STC-specific guidelines for our current residents).  Check out the extracorporeal organ support section.

Disclosure: *I am one of the webmasters for the STCMTCC, but have no affiliation with MCCP other than as an enthusiastic reader.

Question

Identify this radiographic finding:

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The benefits of calcium treatment for hyperkalemia have historically been attributed to “membrane stabilization,” as it has been hypothesized to restore cardiac resting membrane potential.  However, the true mechanism by which calcium improves cardiac function in this setting remains unclear. This has led to inconsistencies in the clinical threshold for treating hyperkalemia with calcium. 

Piktel et al. recently conducted an experimental study investigating the adverse electrophysiologic effects of hyperkalemia and therapeutic effects of calcium treatment in isolated canine myocytes using ex vivo tissue and in vivo cellular techniques. 

Key study findings:

Effects of hyperkalemia:

• Slowed cardiac conduction velocity by 67% ± 7% (p<0.001)
• Shortened cardiac action potential duration by 20% ± 10% (p<0.002)
• Elevated cardiac resting membrane potential
• Caused QRS widening in all preparations, with appearance of the “sine wave” pattern in severe hyperkalemia

Effects of calcium treatment in the setting of hyperkalemia:

• Increased cardiac conduction velocity by 44% ± 18% (p<0.002)
• Caused narrowing of the QRS complex and normalization of ECG
• NO effect on action potential or resting membrane potential
• Effects were reversed with the addition of L-type calcium channel blockade with verapamil

Limitation: 

• Does not account for concomitant acidosis, bradycardia, or arrhythmias which may be present in patients with hyperkalemia

Bottom line: Findings of this study suggest that calcium's beneficial effects in hyperkalemia are not attributed to “membrane stabilization,” but rather to restoration of conduction velocity through L-type calcium channels and subsequent narrowing of the QRS complex. This supports calcium treatment in hyperkalemia when the ECG shows conduction slowing and QRS widening.

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Airway management in the pre-hospital setting is a matter of much controversy, and overall I will defer to my EMS colleagues, but several previous studies have failed to show a benefit to endotracheal intubation in the field as opposed to alternate approaches like a supraglottic airway.  Another nod in this direction has recently come out, with Battaglini et al performing a post-hoc analysis of one of the larger studies in the history of cardiac arrest, TTM-2, looking specifically at outcomes stratified by pre-hospital airway management strategy.  

Do patients who undergo endotracheal intubation in the field do better than those who get a supraglottic airway?

No, they don't.  TTM-2 included 1900 patients, of whom 1702 had enough data to be included in this re-analysis.  28% got supraglottic airways, and 72% got endotracheal intubation.  The groups were reasonably well matched on most characteristics, and if anything most well-known prognostic factors favored the endotracheal intubation group (very slightly).  It should be noted that several outcome metrics, including modified Rankin scale, did show slight signs of benefit for the endotracheal intubation group, even sometimes in a statistically significant fashion, but fell out when a multi-regression analysis, which was the primary endpoint, was done.  

Bottom Line: In pre-hospital cardiac arrest, there remains limited data to support the notion that endotracheal intubation results in better outcomes than supraglottic airway placement.  You should defer to your local protocols and continue to work with your paramedics and EMS directors as evidence continues to evolve.  For now, I don't think there's sufficient data to suggest that a given patient should be intubated vs undergoing supraglottic airway placement, and it is probably best to defer to the judgement, training, and protocols of your folks on scene.

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Question

Identify this injury and other associated injuries:

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Predicting which blunt abdominal trauma patients have mesenteric or  bowel wall injuries early in their ED course will decrease morbidity and mortality. It is also a challenge even in the age of advanced CT imaging. This study from India looks at the Bowel Injury Prediction Score as a possible means to catch these injuries early in the course of care. The score uses white blood cell count over 17,000 (1 point), abdominal tenderness at the time of presentation(1 point),  as well as a McNutt's scoring scale grade 4 (1 point) (table). The study found those with a score greater than 2 (out of 0-3) were much more likely to have bowel or mesenteric injury at time of laparotomy.  Tenderness and CT findings were more likely to be predictive of bowel injury than WBC greater than 17,000. “BIPS had 94.5% sensitivity, 72% specificity, 88% PPV, and 86% NPV for identifying patients with sBBMI.”

My take away is an abnormal CT scan or significant tenderness of presentation warrant concern for mesenteric or bowel wall injury and surgical evaluation is appropriate for these patients. An elevated or normal white blood cell count isn't helpful in these patients. Surgeons may use this scale to help them decide if a patient warrants a trip to the operating room  

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