Emergency Medical Minute

Contributor: Taylor Lynch, MD
Educational Pearls:

What is the oculocardiac reflex? 
The oculocardiac reflex occurs when pressure or traction is put onto the globe of the eye or extraocular muscles that causes increased stimulus to the ophthalmic division of the trigeminal nerve (Cranial Nerve V). 

The trigeminal nerve then has a reflex arc with the vagus nerve (Cranial Nerve X) causing it to be stimulated and create downstream outward parasympathetic effects. 

The activated vagus nerve will cause an inhibitory signal to be sent to the heart, causing bradycardia.

This bradycardia can also be present as certain arrhythmias like AV blocks. 

What are the patient presentations and treatment considerations for the oculocardiac reflex? 
In the emergency department or pre-hospital field it can present in patients with frank orbital trauma with otherwise unexplained bradycardia including: blow-out fractures, retrobulbar hematoma, foreign bodies in the eye, or be caused from eye-dressings placed too tightly. 

For treatment, the most important step is recognizing the condition and removing the offending agent that may be causing the reflex, and seeking to reduce pressure. 

It is also important to have the patient on cardiac monitoring.

If that is not effective, atropine can be considered at 0.5mg repeat doses to improve the bradycardia, but ultimately trying to end the reflex arc is important. 

 
References
Chua AW, Chua MJ, Leung H, Kam PC. Anaesthetic considerations for strabismus surgery in children and adults. Anaesth Intensive Care. 2020;48(4):277-288. doi:10.1177/0310057X20937710

Arnold RW. The Oculocardiac Reflex: A Review. Clin Ophthalmol. 2021;15:2693-2725. doi:10.2147/OPTH.S317447

Summarized by Dan Orbidan, OMS3 | Edited by Dan Orbidan & Ahmed Abdel-Hafiz, NREMT-P
 
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Contributor: Jeffrey Olson, MD
Educational Pearls:
 
What are they?
A flexible balloon and suction tube that we insert into the esophagus and into the stomach to stop bleeding.

When to use?
Typically used for variceal bleeding. Use whenever the patient is too unstable to be transferred to more definitive therapy.

What are the different types?
Linton - Nachlas Tube

Single gastric balloon with a suction port for the stomach and sometimes a suction port for the esophagus.

Sengstaken - Blakemore Tube

Gastric balloon and esophageal balloon with only a gastric suction port

Minnesota Tube

Both gastric and esophageal balloon and both gastric and esophageal suction ports

How do you place one?
Before placement

Secure the airway first in a patient with massive ongoing hematemesis

Insertion

Fully lubricate the tube.

Remove the white caps from the gastric and esophageal inflation ports.

Test your balloons by placing them in the water and inflating them using your syringe.

Place your three-way stopcocks on your esophageal and gastric inflation ports.

Insert the tube similar to an OG tube until you have reached the 50 cm mark for the gastric balloon 

Use a slip syringe at the gastric aspiration site and auscultate to confirm that you are in the stomach. Then fill the gastric balloon with 50 cc of air.

Verify the placement of the gastric balloon with a chest x-ray. (You can also pre-check with ultrasound)

Fully inflate the gastric balloon

Blakemore: 250ccs

Minnesota: 450-500ccs

Apply traction to the tube by tying a roller bandage to the end of it and then the other end to a 1L bag of IV fluids. Then hang the roller bandage over an IV pole.

Place the nasogastric tube down to the pre-measured level above the gastric balloon and suction the esophageal space. If there is continued bleeding coming from the nasogastric tube then you will need to inflate the esophageal balloon.

Note that Minnesota tubes already have their own esophageal suction port and will NOT need this NG tube placement to suction the esophagus.

Use a "manometer" to inflate the esophageal balloon to 30mmHg. If bleeding persists, you can go to a maximum of 45mmHg

What are some tricks?
Using silk ties to add an accessory NG tube to add an extra suction port to a Blakemore tube

Using a bougie to help advance

Put the tube on ice to increase stiffness and make it easier to pass

Use Macgills to help advance

Use a laryngoscope

Use endoscopic biopsy forceps threaded down the gastric port

What does the data say?
"The overall success rate of initial hemostasis with [Blakemore] tube was 75.8. Rebleeding rate after successful initial hemostasis with [Blakemore] tube was 22.0%, and esophageal rupture occurred in 6.1%. Mortality within 30 days was 42.4%" (Choi, 2017)

References
Choi JY, Jo YW, Lee SS, Kim WS, Oh HW, Kim CY, Yun EY, Kim JJ, Lee JM, Kim HJ, Kim HJ, Kim TH, Jung WT, Lee OJ, Kim RB. Outcomes of patients treated with Sengstaken-Blakemore tube for uncontrolled variceal hemorrhage. Korean J Intern Med. 2018 Jul;33(4):696-704. doi: 10.3904/kjim.2016.339. Epub 2017 Nov 10. PMID: 29117668; PMCID: PMC6030415.

https://www.aliem.com/trick-inflating-esophageal-balloon-blakemore-minnesota-tube-without-manometer/

https://www.tamingthesru.com/blog/air-care-series/balloon-tamponade-of-variceal-hemorrhage

https://radiopaedia.org/articles/esophageal-balloon-tamponade-device

https://simkit.co/blakemore-minnesota-and-linton-tube-tips-and-tricks/

https://www.bjaed.org/article/S2058-5349%2817%2930055-0/fulltext

 
Summarized by Jeffrey Olson MD | Edited by Jeffrey Olson MD
 
Special thanks to Dr. Travis Barlock, Dr. Evan Fisch, and the Corewell Health East - William Beaumont Emergency Medicine Residency Program for their contributions in researching for this episode.
 
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Podcast 1025: Post intubation Sedation
Contributor: Aaron Lessen, MD
Educational Pearls:
 
Experts suggest that anyone who is put on a ventilation should be given sedation.
When acquiring Rapid Sequence Intubation (RSI) medications and kits, one should also plan their sedation strategy and always consider the patient becoming unstable hypotensive after their intubation.

 
References
Needleman R, Dyer S, Martinez KA, Routsolias JC. Optimizing administration and timing of post intubation analgesia and sedation in the Emergency Department. Journal of Emergency Nursing. 2025;51(2):215-219. doi:10.1016/j.jen.2024.10.011

Baumgartner K, Fuller BM. Post-intubation sedation and analgesia in the emergency department: The basics and beyond. Emergency Medicine Clinics of North America. 2026;44(4):583-596. doi:10.1016/j.emc.2026.02.004

Rosenberg H, Hendin A, Rosenberg E. Just the Facts: Postintubation sedation in the emergency department. CJEM. 2020;22(6):764-767. doi:10.1017/cem.2020.437

Romagnoli, S., Matta, B., Driver, B.E. et al. A plea for enhanced monitoring of depth of sedation in patients who are intubated and ventilated. Crit Care 28, 342 (2024). https://doi.org/10.1186/s13054-024-05105-9 

 
Summarized by Aaryn David | Edited by Aaryn David  & Ahmed Abdel-Hafiz, NREMT-P
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Contributor: Taylor Lynch, MD
Educational Pearls:
Excessive caffeine intake can be dangerous.

For normal adults, the toxicity level starts at 1000mg, which is equivalent to about 10 cups of coffee or 5 celsius drinks. 

For normal adults, lethal levels are about 5-10 grams, which is equivalent to about 50-100 cups of coffee. Most of these outcomes are not from drinking caffeine, but instead concentrated caffeine pills.

For children, toxic levels are 15mg per kg of the child. 

 
Within the last 10 years 20-40 deaths due to caffeine intake have been reported.

This may be lower than the actual number due to cardiac arrests that potentially could have been caused from caffeine intake. 

 
Clinical presentation of caffeine toxicity can present in many ways.

Most common symptoms include agitation and jitteriness

The far end of the spectrum includes seizures, tachydysrhythmias, and eventually cardiovascular collapse.

 
Caffeine is a part of the methylxanthine class. 

Caffeine is a phosphodiesterase inhibitor, which causes the release of calcetamines that act on your beta-2 receptors. This activates the sodium potassium ATPase and causes potassium to shift intracellular. 

The clinical presentation of this mechanism is a patient with low potassium and agitation.

 
Treatments for toxic caffeine levels include:

Replacing potassium, but slowly since the total potassium levels in the body are normal and will eventually return to normal once the caffeine wears off.

Benzodiazepines

Activated charcoal

Dialysis, since caffeine is dialyzable

References
National Center for Biotechnology Information. "PubChem Compound Summary for CID 2519, Caffeine" PubChem, https://pubchem.ncbi.nlm.nih.gov/compound/Caffeine. Accessed 9 July, 2026. 

Murray A, Traylor J. Caffeine Toxicity. [Updated 2025 Feb 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532910/

Cyril Willson, The clinical toxicology of caffeine: A review and case study, Toxicology Reports, Volume 5, 2018, Pages 1140-1152, ISSN 2214-7500, https://doi.org/10.1016/j.toxrep.2018.11.002.

 
Summarized by Aaryn David | Edited by Aaryn David & Ahmed Abdel-Hafiz, NREMT-P



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Contributor: Aaron Lessen, MD
Educational Pearls:
Case review of a patient with recurrent episodes of syncope and shortness of breath, during which she is found to have intermittent runs of polymorphic ventricular tachycardia

Torsades de pointes is polymorphic ventricular tachycardia occurring in the setting of a prolonged QT/QTc

Risk of torsades increases substantially when QTc exceeds 500ms

Causes:

Common reversible causes include QT-prolonging medications, hypokalemia, hypomagnesemia, hypocalcemia, bradycardia, and structural heart disease

Congenital causes of a prolonged QT interval are primarily inherited genetic mutations affecting cardiac myocyte ion channels leading to delayed ventricular repolarization

Treatment: 

Stop any QT-prolonging medications and correct electrolytes

IV magnesium to suppress recurrent torsades

Increasing the heart rate with isoproterenol or temporary pacing can prevent the pauses that trigger recurrent episodes

If the rhythm degenerates into ventricular fibrillation → defibrillate

 
References
Wigginton JG, Agarwal S, Bartos JA, Coute RA, Drennan IR, Haamid A, Kudenchuk PJ, Link MS, Panchal AR, Pelter MM, Del Rios M, Rodriguez AJ, Perman SM, Sanko S, Kotini-Shah P, Kurz MC. Part 9: Adult Advanced Life Support: 2025 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2025 Oct 21;152(16_suppl_2):S538-S577. doi: 10.1161/CIR.0000000000001376. Epub 2025 Oct 22. PMID: 41122884.

 
Summarized by Meg Joyce, MS3 | Edited by Meg Joyce & Ahmed Abdel-Hafiz, NREMT-P
 
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