• Nitrous oxide (N2O) aka “laughing gas”, used clinically for its psychotropic properties as an inhalational anesthetic, is one of the most abused inhalants for decades due to its unregulated wide availability and public perception that it is a safe high. Social media trends have popularized use by teens and young adults.
• Easily purchased online, in groceries stores, gas stations,  smoke and vape shops it is used as a food processing  propellant in steel aerosol containers like whipped cream and available in small canisters marketed as whipped cream chargers called “whippets”.
• Between January 1, 2014 - Dec 31, 2023, nitrous oxide nearly doubled in exposure rate with a total of 2,322 exposures reported to U.S Poison Centers.  From 2010-2023,  1240 US deaths were reported between the ages of 15-74 attributable to nitrous oxide poisoning.
• Similar to Ketamine and phencyclidine, nitrous oxide causes antagonism at the NMDA receptor resulting in short lived reversible euphoria and sedation and analgesic effects through the K-opioid receptor.
• Nitrous oxide fatalities occur primarily due to asphyxiation and oxygen deprivation causing neurologic sequela, hypotension, arrythmias, and death. N2O depresses the sensation of shortness of breath so users may not seek fresh air.
•  Chronic recreational N2O exposure impedes vitamin B12 function and causes a distinct neurological syndrome manifested by numbness, gait disturbances, loss of coordination, changes in mentation, and loss of bowel and bladder control, and hematologic abnormalities.
• On June 6, 2025, the FDA issued a public advisory warning consumers not to inhale nitrous oxide products due to potential for severe adverse events if used for recreational nonfood purposes.

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We have all been there – an ED patient with circulatory shock requiring vasoactive medications and, therefore, an arterial line for accurate and close monitoring of the MAP and appropriate titration of the infusions. But does it save lives?

The recently published NEJM article by Muller et al. takes a look at noninvasive BP monitoring (NIBP) by cuff versus early arterial catheterization in patients with hypotension and evidence of tissue hypoperfusion: 

• Open-label, pragmatic, parallel-group, noninferiority, multicenter RCT across 9 ICUs in France
• Adult patients enrolled within 24h of ICU admission, randomized to NIBP (n=506) or arterial line placement within 4h of enrollment (n=504)
  • 15% of NIBP group received art line during study period as deemed necessary by predefined safety criteria (unable to get NIBP or SpO2, for ex)
  • 50% septic shock, >90% medical patients, 90% on pressors at randomization
• Notable exclusions: BMI >40, high-dose vasopressors (total norepi tartrate* + epi infusion rate >2.5 mcg/kg/min) 
• Findings: 
  • No difference in primary outcome of 28-day mortality (34.3% NIBP vs. 36.9% art line)
  • No difference in 90 day mortality, 28-day ventilator, vasopressor, or RRT-free days
  • More arterial puncture attempts in the NIBP group (742 vs. 269 per 1000 ICU days)
  • No increase in arterial line-associated infections or ischemia
  • More (8 vs 1%) hematoma or hemorrhage at art line site in arterial line group
  • More patients in NIBP group reported serious pain/discomfort related to device (13 vs 9%)

Bottom Line: This trial indicates that in appropriately-selected patients with shock, such as those not on high doses of vasopressors, with BMI < 40 and an ability to consistently obtain NIBP measurements, early arterial line placement in the ED for vasopressor titration is unlikely to improve outcomes. It is important to note other potential indications for arterial line placement (severe hypoxia, inability to obtain reliable SpO2 with need for ABG monitoring, cardiac arrest, pain related to NIBP cuff monitoring, intracranial hemorrhage, etcetera) may still make arterial line placement in the ED prudent and better for overall patient care.

*France refers to norepi by the tartrate formulation dose, US refers to the base norepi dose (ratio is 2:1 tartrate: base).

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POCUS can be performed at the bedside to evaluate for acute scrotal conditions, including testicular torsion and inflammatory processes such as epididymo-orchitis. 

A high-frequency linear transducer is typically used to scan the scrotum in two different planes. Additionally, a coronal "buddy view"—displaying both testes side by side—can aid in comparing echogenicity and vascularity.

On B-mode imaging, both testicular torsion and inflammatory conditions may present with testicular swelling and decreased homogeneity. However, color and power Doppler imaging can help to differentiate:

• Inflammatory conditions (e.g., epididymo-orchitis) typically show increased vascular flow on color and power Doppler.

• Testicular torsion usually demonstrates reduced or absent flow in the affected testis. However, in cases of intermittent torsion-detorsion, vascular flow may appear preserved or even increased. In such scenarios, repeat Doppler imaging after one hour may help clarify the diagnosis.

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Intraabdominal infections leading to sepsis can come from cholecystitis, small bowel perforation, gastric perforation, left sided colonic diverticulitis, right sided diverticulitis and appendicitis. When to initiate source control and antibiotics is controversial. These authors propose breaking patient populations into three groups:

• Class A Healthy patients have no or else well-controlled comorbidities, and no immunocompromise, so that the IAI is the main problem.
• Class B Patients with moderate comorbidities and/or moderate immunocompromise are at risk of adverse outcomes due to their predisposing conditions, but are currently clinically stable. However, the IAI could rapidly worsen the prognosis.
• Class C Patients with severe comorbidities with advanced stages and/or severe immunocompromise, in which the infection worsens an already severe clinical condition.

From this they propose algorithms to treat these intraabdominal infections such as (note the different approach to right and left diverticulitis):

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This article looks at source control as it relates to intrabdominal sources for sepsis.  Key take aways are:

1. They believe surgery is the best service to mange these complex patients in consultation with medicine, heme-onc, transplant, EM, etc.  (Is that how it is done at your institution?)
2. Source control should be both anatomic as well as physiologic (below)
3. Timing of source control is controversial
4. Antibiotic stewardship is still important even in these complex patients

Those at high risk of morbidity and mortality from intraabdominal infection associated sepsis include: 

Mild–moderate immune deficiency: Elderly (according to the age and general status of the patient), Malnourished, Diabetic, Burns, Trauma, Uremic, Active malignancy, not on chemotherapy, HIV with CD4+ count >200/mm3, Splenectomized, Severe immune deficiencyAIDS HIV with CD4+ count <200/mm3, Transplant (solid organ, bone marrow), High-dose steroids (more than 20 mg/day prednisone), Malignancy on chemotherapy, Neutrophil count <1,000/mm3

High-risk population (medical or surgical causes)Low serum albumin concentration Older age Obesity Smoking Diabetes mellitus Ischemia secondary to vascular disease or irradiation Prolonged or delayed/late procedures

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Comparing prescribing patterns from early 2000s to late 2010s in the National Hospital Ambulatory Medical Care Survey,  these authors found we continue to under prescribe pain medications to non-white patients for traumatic injuries.

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A prospective cohort of South Korean patients over 65 years admitted from the ED with critical illness had  Clinical Frailty Scale (CFS) performed on them. Those with a high CFS had increased 3 month mortality. CFS helps us prognosticate morbidity and mortality in our older critically ill patients. 

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Food for thought on this Thanksgiving eve…

AI is rapidly being integrated into the practice of emergency medicine, as well as many other medical specialties.  Similar to the adage, "you are what you eat," AI is what we feed it.  See below for an introduction to the various levels of bias contributing to the machine learning process:  

For a deep dive into the world of bias in AI, see referenced article.

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Settings: this is a meta-analysis of 17 observational studies about boarding of critically ill patients in US Emergency Departments. All studies were from urban, academic centers.

Participants:

• There was a total of 407,178 patients, 194,814 (485) were boarding vs. 212,364 (52%) non-boarding patients.
• 355,86 (87%) patients were at centers with the presence of a resuscitation service.
• Ther was a mixture of critical illnesses: trauma (29.4 %), medical conditions (29.4 %) and mixed critical illness (41.2 %).

Outcome measurement: all cause mortality, as reported by the authors of the original studies.

Study Results:

• Overall, boarding patients were not associated with higher mortality, than non-boarding patients (Odd ratios 1.06, 95 % CI 0.94–1.19 p=0.383).
• Boarding patients were not associated with longer hospital length of stay (mean difference 0.38 days, 95%CI 0.94-1.50, P=0.51).
• However, among subgroup analyses, boarding patient population with mixed critical illnesses was associated with higher odds for mortality (OR 1.2, CI 1.04–1.4, p = 0.02 ) and longer HLOS (difference = 1.9, 95 % CI 0.81–3.1, I2 = 0 %, p = 0.001).

Discussion:

• All studies were observational so there was risk of bias and there was a presence of a small publication bias. This means that there were a few unpublished studies out there that showed that Boarding patients might have better outcomes.
• The findings that patient population with mixed illnesses were associated with higher odds for mortality, compared with Trauma-only or medical-only patients, might suggest that ED are not well equipped to take care of a wide spectrum of disease states. We seem to do better with populations with protocols such as sepsis, stroke, trauma.
• There was no clear consensus about how researchers approach this topic. A few studies did not even report their patient populations’ age (I cannot understand how these got published). Researchers used different thresholds for boarding, likely reflecting their institutional variabilities. There was quite a significant heterogeneity about patients’ acuity: some studies used SOFA, others used mSOFA.
• All of the studies were from urban academic centers so their results may not be applicable to non-academic centers which may not have many boarding issues

Conclusion: 

Critically ill patients boarding in the U.S. Emergency Departments were associated with a non-statistically signi?cant increase in odds of mortality and hospital length of stay compared to non-boarded patients

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The role of sodium bicarbonate in the treatment of severe acidemia has been controversial, with some studies suggesting no benefit, and others indicating that it may help reduce need for renal replacement therapy (RRT) and even improve mortality. The BICARICU-2 Trial was an open-label multicenter RCT conducted in France that evaluated the impact of a bicarb infusion among patients with metabolic acidosis and moderate to severe AKI. 

There was no difference in 90 day mortality, but patients in the bicarb group were less likely to be started on RRT (38% vs 47% in the control group) using pre-defined criteria for RRT initiation, and had a 50% lower rate of bloodstream infections. Patients in the bicarb group who were started on RRT met criteria for RRT later than those in the control group (median 31h vs 15.5h).

Study Details:

Patient Population: 

• SOFA score >4 OR arterial lactate > 2mmol/L within 48h of ICU admission
• Metabolic acidosis, defined by pH < 7.2, HCO3- < 20mEq/L, and PaCO2  < 45mmHg
• Moderate to severe AKI, defined as Cr >2.0 x baseline or UOP < 0.5 mL/kg/h for >12h. 
• Patients with severe baseline CKD, ketoacidosis, intoxication with exogenous acids (metformin, salicylate, methanol, ethylene glycol), or ongoing bicarb losses via GI or urinary tracts were excluded.
• The presumed etiology of acidemia was septic shock in over half of included patients, and over 75% were on vasopressors.

Intervention: 

• 4.2% bicarb infusion administered in 125-250 aliquots with a target pH >7.3, though not to exceed 1L/500mEq within 24h. 
• The intervention continued for a maximum of 28d or until ICU DC. 
• Patients in the intervention group received a median of 750mL in the first 48h.

RRT Triggers:

• Immediate: K > 6.5mEq/L with EKG changes or cardiogenic pulmonary edema with no UOP and hypoxia
• 24h after enrollment: UOP <0.3 Ml/kg/h over 24h, pH <7.2 despite resuscitation, K > 6.5 MEq/L.

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Treatment of Staphylococcus aureus bacteremia has traditionally required several weeks of intravenous antibiotics. This approach carries medical risks, such as catheter-associated infection or thrombosis, as well as significant social and financial burdens for patients. Dalbavancin, a long-acting intravenous lipoglycopeptide with activity against S. aureus (including MRSA), has been proposed as a more convenient alternative. This study evaluated the efficacy and safety of dalbavancin compared with standard therapy for S. aureus bacteremia.

Two hundred adults were enrolled in this open-label, randomized clinical trial, which was conducted in the United States and Canada. After blood cultures cleared, participants were randomized to complete therapy with dalbavancin (administered on Days 1 and 8) or with standard treatment (cefazolin for MSSA and vancomycin or daptomycin for MRSA).

The primary outcome was the Desirability of Outcome Ranking (DOOR) at Day 70, incorporating five domains: clinical success, infectious complications, safety events, mortality, and health-related quality of life.

Dalbavancin was not superior to standard therapy for treating S. aureus bacteremia, and adverse events were similar between groups. A key strength of this study was the inclusion of people who inject drugs, a population at high risk for S. aureus bacteremia and often underrepresented in trials. A major limitation was that the DOOR metric did not account for important social and economic factors, such as disposition (home versus skilled nursing facility), caregiver burden, or treatment cost.

Key Takeaway: Dalbavancin may be a suitable alternative to traditional therapy for Staphylococcus aureus bacteremia, offering less frequent dosing and a shorter treatment course. Further research is needed to identify which patients benefit most and to evaluate its impact on social and economic factors such as discharge disposition, caregiver burden, and treatment costs.

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In 252 mild traumatic brain injury patients seen at 3 level I centers that were given the Rivermead Post Concussion Symptoms Questionnaire within 24 hours of arrival, 3 month post concussive symptoms were significantly correlated with their score on the questionnaire. This questionnaire take 3 minutes to complete. This may be helpful in prognosticating who will have post-concussive symptoms and who will need additional follow up.

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Turf Toe:

Increased recent attention due to injuries in high profile athletes

Sprain of the first MTP joint

Mechanism: Forced hyperextension of the great toe (most common)

https://briandorfman.com/wp-content/uploads/2015/11/b_12_3_6a.jpg

Causes injury to the MTP joint capsule and surrounding ligaments

Presents as pain, swelling, discoloration, tenderness to palpation, possible joint laxity

Pain with active and passive ROM (both flexion and extension)

Graded 1-3 (Sprain, partial rupture, significant/complete rupture)

Most commonly seen in athletes who compete on artificial turf.  

              More rigid than natural grass

              Synthetic surfaces do not release cleats as easily as natural grass 

              Improved synthetic surfaces perform more similar to natural grass

Much higher incidence in games vs practices.

In football, quarterbacks and running backs at highest risk

Between 30 and 45% of professional football players claim that they have experienced a turf toe injury, with over 80% of those injuries occurring on artificial turf 

The combination of more rigid synthetic surfaces and lighter, more flexible shoes, increase risk of hyperextension injuries

Treatment: usually non operative

Rest/ice/taping after acute swelling decreased/stiff sole shoe/crutches/NSAIDs.

Consider walking boot or short leg splint for severe injuries

Less than 2% of injuries require surgery

Children account for up to 20% of emergency department visits.  In the US, up to 90% of children’s visits to emergency departments are to general EDs.  The weighted pediatric readiness score (WPRS) was developed to assess the level of readiness of emergency departments to care for pediatric patients. The last assessment was in 2013 showed a mean score of 68.9.  High readiness scores have been associated with decreased mortality.  The same holds true for children with injuries presenting to trauma centers.  The higher the WPRS score, the lower the risk of in hospital death.  There was no difference if the patient presented in cardiac arrest.  A 10 point increase in WPRS is associated with a lower odds of potentially avoidable transfers in both trauma and medical patients.  More recent data has been collected, but has not yet been published.  More information on pediatric readiness (for hospitals and EMS) can be found at: https://emscimprovement.center/domains/pediatric-readiness/. 

Bottom line: Being Pediatric Ready improves the care of children.

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In reviewing the limited literature available, the authors found that fascia iliaca blocks did not improve mortality but did improve hospital length of stay,  decreased opiate use, and decreased delirium rates. More research is needed, however this tool should be added to our multimodal pain control toolbox.

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Early defibrillation is a key step in the cardiac arrest chain of survival.  Public Access AEDs may be available more readily than waiting for first responders.  Outside of simple awareness of where AEDs are located, there are newer ways to become aware of public AEDs near a cardiac arrest including cell phone apps or information given by 911.  A British study showed that only 5.9% of AEDs were within 100 meters of the patient and 35% were within 500 meters.  The distance between the AED and arrest may be a barrier for bystander AED use.  This study looked to determine the time required to retrieve an AED and they hypothesized that a distance > 400 meters would be longer than the EMS response times. 

This study used 15 women and 15 men to perform different runs in various environments in different seasons, retrieving AEDs at 200m through 600m and bringing it back to the patient.  In these scenarios, only the 200m distance (400 m round trip) times were deemed to allow enough time to apply and use the AED prior to EMS arrival.  Barriers to AED retrieval included traffic lights, cars, weather and pedestrians.

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Question

This is an actual patient case:

65 y/o pt intubated for hemoptysis and started on nebulized transexamic acid. Overnight, the pt is found to have severe breath stacking/auto-PEEPing and consequently is started on neuromuscular blockade. The pt has no history of asthma or COPD and the ETT is clear without obstruction. 

Ventilator waveforms are as shown. What is the issue?

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This group looked at 88 patients intubated for penetrating neck injury and found 95% received neuromuscular blocking agents, 73% were intubated using a bougie, and 95% were intubated on first pass. 

The authors concluded; “Rapid sequence intubation with bougie use was an effective default approach to definitive airway management in ED patients with penetrating neck trauma.”

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This abstract from ACEP's most recent research forum looked at the effect a patient's preferred language had on ED LOS, rate of admission, hospital length of stay and resource utilization both in the ED and the hospital.

Overall, those patients who spoke English as their primary language had lower ED LOS,  less testing done in the ED, but if they got admitted they had the longest hospital LOS.  Patients who preferred Spanish language had the shortest hospital LOS and were most likely to be discharged home with no services. Non-English/non-Spanish languages had the longest ED LOS and highest admission rates and had similar resource use as patients who preferred Spanish

This abstract opens the door for further research into what the underlying cause of these disparities are.

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This pearl was adapted from a literature update presented by Castin Schulz, PharmD on November 13, 2025.

A 2025 study in the American Journal of Emergency Medicine provides new real-world data on the two most common reversal agents for factor Xa (fXa) inhibitor-related intracranial hemorrhage (ICH).

This national retrospective cohort study evaluated 350 Veterans who received either andexanet alfa (AA) or 4-factor prothrombin complex concentrate (4F-PCC) for fXa inhibitor-related ICH.

Key Findings (Propensity-Matched Analysis)

• Effectiveness (Mortality): There was no significant difference in the primary effectiveness endpoint of 90-day mortality between the two groups.
  • AA Group: 30.9% mortality
  • 4F-PCC Group: 36.6% mortality
  • (p=0.35)
• Safety (Thrombosis): The AA group experienced a significantly higher rate of 30-day thrombotic events.
  • AA Group: 11.4% thrombotic events
  • 4F-PCC Group: 2.4% thrombotic events
  • (p<0.01)
• Specific Risk: The primary driver for this difference was a significantly higher rate of acute ischemic stroke (AIS) in the AA group (6.5% vs. 0.8%, p=0.02).

Clinical Takeaway

In this study of Veterans with fXa inhibitor-related ICH, andexanet alfa did not improve 90-day mortality compared to 4F-PCC. However, its use was associated with a significantly increased risk of 30-day thrombotic events, particularly ischemic stroke.

This study adds to a growing body of literature questioning the safety profile of AA. The authors conclude that the selection of AA should be carefully weighed against the patient's underlying risk of thrombotic events.

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