Lit Matters + Longevity in EM

In the first of a new recurrent segment series on ERcast: Clinical Perspectives, Cam Berg introduces us to Nick Kanaan, MD - a fellow EM physician with an impressive resume and colorful personal experiences in Wilderness and Hyperbaric medicine.  Then, in this month's Lit Matters segment, Cam and Brett review the literature surrounding the diagnosis and treatment of SCAPE.

 

Career Longevity in Emergency Medicine

Cam Berg, MD and Nicholas Kanaan, MD

 

Background:

• This will be a new and recurring segment on ERcast: Clinical Perspectives
• These segments will be long-form interviews with influential and innovative emergency medicine physicians. 
• The goal is to give listeners—whether trainees, early career, or seasoned clinicians—a refreshed perspective on clinical practice and to spotlight the many “EM-adjacent” avenues available beyond standard shift work.
• The debut guest is Dr. Nicholas Kanaan.

 

Introducing Dr. Kanaan:

• Background:  Stanford for undergrad, UC San Diego medical school, Stanford EM residency.
• Fellowship: Wilderness Medicine/EMS at the University of Utah.
• This additional training links his passion for the outdoors and his career in EM.
• He sees Wilderness fellowship, not as a path to riches, but rather a way to align profession, passion, and play.

 

Wilderness Medicine Training:

• Wilderness medicine fellowship training is a mix of intensive didactics and practical field work: 
• Environmental illness (hypothermia, frostbite, heat illness, altitude illness), avalanche, and exposure medicine
• Toxicology
• Marine/aquatic medicine 
• Envenomations
• Improvised medicine  - resource-limited environments, expedition/travel/tropical medicine
• Includes search-and-rescue operations and hands-on skills like rope rescue, mountaineering, climbing/knots, and survival training.
• It also includes an expectation of scholarly contribution through research. 
• His fellowship and subsequent work opened doors to experiences such as SAR leadership, ski patrol process improvement, and expeditions, including clinical work near Everest Base Camp, dive medicine travel, and high-altitude climbing.

 

Dr Kanaan’s Research and Expertise:

• Altitude illness:
• Authored a landmark 2012 Annals study on ibuprofen for acute mountain sickness prophylaxis. 
• The idea came from a medical student observational project at different altitude research stations, where anti-inflammatory use correlated with lower AMS symptom scores. 
• Later, he helped lead a double-blind randomized trial comparing ibuprofen (600 mg three times daily, started the day before ascent) with acetazolamide in a non-inferiority design, reporting a reduced incidence of AMS and a number needed to treat of about four. 
• The findings suggested ibuprofen improved the broader AMS symptom constellation rather than merely masking headache, positioning it as a practical alternative for some patients given acetazolamide’s common side effects.
• Pit Viper Envenomation Management:
• Confirm the likely snake type for which antivenom is effective.
• Do not apply field interventions like tourniquets or pressure immobilization for North American pit vipers because their venom drives local tissue injury—trapping venom locally can worsen damage. 
• In the ED, use antivenoms like CroFab and ANAVIP. 
• Expensive,  but undertreating due to cost concerns can increase morbidity.
• Dose and redose based on clinical response and allow time for antivenom to work. 
• Surgical consultations prompted by alarming limb appearance are often unnecessary.  
• Fasciotomy is not a routine early management tactic and should be reserved for select cases, with compartment pressures measured when concern exists rather than relying solely on classic “5 Ps.”
• Hyperbaric medicine: 
• Dr. Kanaan initially pursued hyperbaric certification to support high-altitude illness research, but local chamber limitations made the study impractical.
• Over time, dive medicine exposure and a staffing need at a smaller hospital led him into wound care and hyperbarics as an “EM-adjacent” side role. 
• Wound care may not seem glamorous, hyperbarics intersects with real ED-relevant pathology beyond carbon monoxide poisoning and decompression sickness, including gas gangrene, crush injury/compartment syndrome and traumatic ischemia contexts, necrotizing infections, refractory osteomyelitis, compromised grafts/flaps, radiation injuries, severe thermal burns, frostbite, and even severe anemia in patients who cannot receive transfusions (e.g., Jehovah’s Witness patients). 
• Idiopathic sudden sensorineural hearing loss as an approved indication.
• Emerging/off-label uses in post-concussive management.
• Longevity & Cognitive Enhancement:
• There is a proposed link between hyperbaric sessions and improved cognition—possibly via increased cerebral blood flow.
• Reported improvements in attention, processing speed, and executive function.
• Findings also suggest telomere-lengthening as a reason for these effects (reported >20% in certain immune cells).

References:

1. Kanaan NC, Peterson AL, Pun M, et al. Prophylactic Acetaminophen or Ibuprofen Results in Equivalent Acute Mountain Sickness Incidence at High Altitude: A Prospective Randomized Trial. Wilderness Environ Med. 2017;28(2):72-78. PMID: 28479001
2. Kanaan NC, Ray J, Stewart M, et al. Wilderness Medical Society Practice Guidelines for the Treatment of Pitviper Envenomations in the United States and Canada. Wilderness Environ Med. 2015;26(4):472-487. PMID: 26433731

 

LIT MATTERS April 2026

Cam Berg, MD and Brett Murray, MD

 

Lit Matters #1:  What Exactly Is SCAPE and How Should We Treat It?

Long B, Brady WJ, Gottlieb M. Emergency medicine updates: Sympathetic crashing acute pulmonary edema. Am J Emerg Med. 2025;90:35-40. PMID: 39799613

 

Background:

• SCAPE (formerly called flash pulmonary edema) is characterized by:
• Rapid onset (minutes to hours).
• Severe hypertension (often SBP >160).
• Acute respiratory distress.
• Marked sympathetic activation.
• Often occurs in patients with known diastolic dysfunction or heart failure.
• Importantly:
• Many patients are not systemically hypervolemic.
• Peripheral edema and JVD may be absent.
• Pathophysiology:
• Sudden catecholamine surge.
• Massive afterload increase.
• Splanchnic vasoconstriction leads to central blood shunting.
• Pulmonary congestion from redistribution — not volume overload.

Clinical Question: What is the evidence-based approach to diagnosing and managing SCAPE in the emergency department?

 

Bottom line:  SCAPE is primarily an afterload problem, not a volume problem.  Early NIPPV and aggressive vasodilation save lives. Diuretics are not universally indicated.

 

What they did:   Narrative review synthesizing available evidence on:

• Diagnosis
• Treatment pillars
• Respiratory support
• Vasodilator therapy
• Role of diuretics
• Adjunct medications

 

What they found:

• Diagnosis
• POCUS is highly sensitive (B-lines in ≥3 lung fields)
• CXR may lag (up to 20% initially negative)
• BNP not helpful in the acute ED setting
• Troponin often elevated (demand ischemia)
• Treatment Pillars
• Non-Invasive Positive Pressure Ventilation (NIPPV)
• Reduces intubation risk (RR 0.49. 95% CI 0.38–0.62)
• NNT ≈ 13 to prevent one intubation
• Mortality benefit (RR 0.65. 95% CI 0.51–0.82)
• NNT ≈ 17 to save one life
• BiPAP preferred over HFNC
• High-Dose Nitroglycerin
• IV boluses 1–2 mg
• Start infusion ~100 mcg/min or higher
• Aggressive afterload reduction decreases:
• Intubation rates 
• ICU admissions
• Hospital length of stay
• Median LOS as low as 12 hours with proper management
• Diuretics (Use Selectively)
• Many SCAPE patients are not volume overloaded.
• Reflexively giving loop diuretics may worsen sympathetic tone.
• Diuretics should be reserved for patients with true clinical hypervolemia.
• Second-Line Antihypertensives:
• If SBP remains >160:
• Clevidipine
• Nicardipine
• Reduce afterload without impairing contractility
• May outperform nitroglycerin in some trials (PRONTO study)
• What to Avoid
• IV beta blockers
• Morphine (associated with increased mortality and intubation)

 

Cam and Brett’s Takeaways:

• SCAPE ≠ volume overload — it's afterload and redistribution.

• POCUS > CXR for rapid diagnosis.
• NIPPV first — mechanical preload AND afterload reduction.
• High-dose nitroglycerin — 500–1000 mcg bolus, 100–200 mcg/min infusion. Don't be timid.
• Diuretics are NOT first-line unless clear systemic volume overload.
• Avoid morphine and beta-blockers.

Lit Matters #2: High-Dose vs Low-Dose Nitroglycerin in SCAPE

Pramudyo M, Kamarullah W, Pranata R, et al. Low-dose versus high-dose intravenous nitroglycerin in the treatment of sympathetic crashing acute pulmonary oedema: a systematic review and meta-analysis focusing on efficacy, safety and outcomes. BMJ Open. 2025;15(6):e099142. Published 2025 Jun 12. PMID: 40506079

 

Background:

• Nitroglycerin is commonly used in SCAPE.
• Traditional dosing (10–50 mcg/min) are inadequate.
• High-dose regimens (>100 mcg/min or bolus strategy) aim to reduce afterload more effectively.

Clinical Question:  Does high-dose IV nitroglycerin improve outcomes compared to low-dose regimens in SCAPE?

 

Bottom Line:  High-dose nitroglycerin is safe and dramatically more effective than low-dose regimens in SCAPE.   Under-dosing leads to worse outcomes.

 

What They Did:

• Systematic review and meta-analysis per PRISMA guidelines.
• Databases: PubMed, Europe PMC, ScienceDirect through November 2024.
• 4 studies (1 RCT, 3 observational)
• 185 patients total
• Mean age - 50.6 ± 14.9 years
• Male - 58.4%
• Prior HTN - 96.2%
• Prior HF - 46.7%
• CKD - 63.2%
• Mean presenting SBP - 211 mmHg
• Mean RR - 39/min
• Mean SpO2 - 88%
• High-dose: Starting infusion ≥100 mcg/min (boluses permitted)
• Low-dose: Starting infusion <100 mcg/min
• SCAPE defined by:
• SBP ≥160
• RR ≥30
• SpO₂ <90%
• Onset <6 hours
• Primary Outcomes:  
• Mechanical ventilation
• Symptom resolution within 6 hours
• LOS
• MACE
• Secondary Outcomes:
• Safety

 

What They Found:

• Intubation
• High-dose nitroglycerin significantly reduced intubation
• RR 0.31 (95% CI 0.10-0.96), p+0.04
• ~70% relative reduction - High quality evidence!
• Symptom Resolution Within 6 Hours
• 4x more likely with high-dose nitroglycerin
• RR 3.88 (95% CI 1.95–7.71), p<0.001
• Hospital Length of Stay
• Reduced by ~48 hours in high-dose group
• (95% CI –93.76 to –1.21), p=0.04
• Major Adverse Cardiac Events (MACE)
• No significant difference
• No increase in adverse events
• 0.41 (95% CI 0.06–2.68), p=0.35
• Hypotension
• No episodes of SBP <90 in either group

• Nitro must be high enough to achieve arterial dilation because SCAPE is an afterload crisis.  Arterial dilation is required.
• Many patients on chronic nitrates have vascular tolerance and will need higher doses.
• Low doses primarily cause venodilation (preload reduction).
• Nursing comfort with high-dose nitro can be a barrier.
• Sublingual nitro perspective: two tabs = 800 mcg — reframes infusion dosing anxiety.

 

Cam and Brett’s Takeaways:

• High-dose NTG (≥100 mcg/min) reduces intubation by ~70% — high certainty.
• High dose NTG is 4 times more likely to achieve 6-hour symptom resolution, which  leads to, on average, a 2 day shorter hospital stay.
• There is no increased hypotension risk.
• The one caveat is that these are small studies with a high population of CKD patients. Clinical judgment is essential.