POTD: C-Collars

Hellooo and welcome to Trauma Tuesday. Today we're going to be discussing c-collars, something that we very frequently see on our patients and very frequently place on our patients.

What is the evidence for it? Are we using c-collars correctly?

C-collars have been recommended by multiple academic societies (surgical, trauma, prehospital, neurological) to be placed pre-hospital if there is a suspected c-spine injury. This recommendation has been in place for ~30 years and has not really changed throughout that time. 

This recommendation has come into question in the past few years given that there aren't many high-quality RCTs truly showing he benefit of c-collars on c-spine injuries and subsequent spinal cord injuries. 

Additionally, conservative estimates show that at least 50-100 patients have c-collars placed on them for every patient that actually has a confirmed c-spine injury - and c-collars are not without harm.

C-collars have been shown to:

• Increase intracranial pressure via jugular venous compression

• Increase difficulty for airway management

• Lead to pressure ulcers when used for an extended period of time

• Lead to patient discomfort

• Lead to increased CT imaging that may not have been necessary per our current evidence

Additionally, there is no evidence that small movements of the spine cause worsening c-spine injury. It's large, forceful impacts against the neck that lead to injury, and if the patient has a c-spine injury, they are unlikely to actively move their neck to a degree that will worsen their injury. 

However, given that c-collars are still standard of practice for anyone with a suspected (or confirmed) c-spine injury, we should still follow standard of practice and hospital protocols. Also, it's understandable that we, as EM providers, want to prevent the worst case scenario of a spinal cord injury. 

But I hope this POTD makes us all think harder about how many c-collars we're placing on our patients and the need for better evidence to support (or not support) this practice. 

References

Booth, K, Helman, A. Backboard and Collar Nightmares from Emergency Medicine Update Conference. Emergency Medicine Cases. May, 2015. https://emergencymedicinecases.com/backboard-and-collar-nightmares-emergency-medicine-update-conference/. Accessed October 7, 2024.

Sundstrøm T, Asbjørnsen H, Habiba S, Sunde GA, Wester K. Prehospital use of cervical collars in trauma patients: a critical review. J Neurotrauma. 2014;31(6):531-540. doi:10.1089/neu.2013.3094

Maschmann, C., Jeppesen, E., Rubin, M.A. et al. New clinical guidelines on the spinal stabilisation of adult trauma patients – consensus and evidence based. Scand J Trauma Resusc Emerg Med 27, 77 (2019). https://doi.org/10.1186/s13049-019-0655-x

Plumb, James O.M.Morris, Craig G. et al. Cervical Collars: Probably Useless; Definitely Cause Harm! Journal of Emergency Medicine, Volume 44, Issue 1, e143

https://www.jems.com/patient-care/why-ems-should-limit-use-rigid-cervical/

https://epmonthly.com/article/collar-care/

https://www.emdocs.net/cervical-collars-for-c-spine-trauma-the-facts/

https://www.emra.org/emresident/article/cervical-collar

POTD: Hematuria

This POTD was requested by one of our star interns and maybe my long lost distant relative, Dr. Alan Chung!

Today, we're talking about hematuria and our approach as EM providers. 

What is it?

Hematuria is defined as >3-5 RBCs per HPF on urine microscopy. Gross hematuria means that, by just looking at the urine, it looks bloody. Just >1ml of blood in the urine can cause gross hematuria.

Causes of hematuria

This is a long and exhaustive list, but common causes we see in the ED include UTIs (cystitis, pyelonephritis), nephrolithiasis, trauma from catheterization, and blunt or penetrating trauma. Also, don't forget to ask your female patients if they are on their menstrual period.

However, can't miss diagnoses include AAA, renal artery embolus/infarct/dissection, renal vein thrombosis. And of course, if the suspicion for malignancy is high, you want your patient to be informed of this possibility and have close follow up. 

Is it really hematuria?

Pseudohematuria, or urine that appears grossly bloody but on urine microscopy actually has no RBCs, can be caused from a variety of reasons. Common ones include rhabdomyolysis, medications such as nitrofurantoin, pyridium, and rifampin, and foods such as beets and artificial food colorings. So, before you start really thinking about what's causing the hematuria, make sure you get a UA and confirm that it is, in fact, blood. 

Work up

Asymptomatic microscopic hematuria can oftentimes be benign, in the absence of any significant risk factors. Oftentimes, if these patients are stable, asymptomatic, and does not have significant risk factors, they can follow up with their primary care doctor.

Painless gross hematuria is more concerning for malignancy, and would benefit from close urologic follow-up. Other risk factors for malignancy include older age, smoking, family hx, hx of occupational exposure. 

Ask about urinary retention - if the pt is passing clots, this may obstruct the urethra, leading to a lower urinary tract obstruction.

Otherwise, if your patient's history, signs/symptoms, or exam points you to another diagnosis (such as nephrolithiasis, vascular disease, nephropathy...etc), you may want to obtain additional labs and imaging. 

Treatment

Once again...depends! As noted above, stable patients with asymptomatic microscopic hematuria can oftentimes follow up with their PCP. Patients with painless gross hematuria but no urinary obstruction, no AKI, and is otherwise stable should be referred for close urology follow up.

If you patient is unable to urinate, has a significant decline in renal function, decline in Hgb/Hct, or of course if you find any of the big bad vascular causes of hematuria, the patient should be admitted. 

Special considerations for pediatrics

In kids, pay special attention to post-infectious glomerulonephritis and Henoch-Schonlein Purpura. 

Gross hematuria with edema, proteinuria, and/or hypertension? -> think renal causes like nephritic/nephrotic syndromes, oftentimes post-infectious glomerulonephritis 

Gross hematuria with abdominal pain and rash? -> think HSP

References

Willis GC, Tewelde SZ. The Approach to the Patient with Hematuria. Emerg Med Clin North Am. 2019;37(4):755-769. doi:10.1016/j.emc.2019.07.011

https://www.emdocs.net/em3am-hematuria/

https://www.emdocs.net/evaluation-and-management-of-hematuria-in-the-emergency-department/

https://www.emra.org/emresident/article/hematuria-management

https://pedemmorsels.com/microscopic-hematuria/

https://www.auanet.org/meetings-and-education/for-medical-students/medical-students-curriculum/urologic-emergencies

https://www.ebmedicine.net/topics/hepatic-renal-genitourinary/pediatric-hematuria

POTD: Cryoneurolysis? What is that?

Welcome to a very exciting POTD inspired by our research extraordinaire and pain management expert Dr. Sergey Motov!

He recently enlightened me on the topic of cryoneurolysis as a pain management modality, and my first response was: what is that? So let's learn together!

What is it?

The use of cold temperature to treat pain using nitrous oxide contained within the cryoneurolysis probe/cannula. Nitrous oxide enters a low-pressure chamber at the end of the cryoneurolysis probe, which causes a precipitous decline in temperature. This decline in temperature leads to axonal injury and analgesia at the intended site. Because cryoneurolysis relies on axonal injury for analgesia, pain control can be achieved for weeks to months. 

For our surgical colleagues, this may be done with direct visualization of the nerve in the OR. For the EM folks, this can be done using an ultrasound-guided approach with a percutaneous cryoneurolysis probe. 

What's the evidence?

A systematic review by Cha et al. (2021) noted that cryoneurolysis may be useful for chest wall pain after surgery or trauma, however many studies are of low quality, and more research is needed. Similarly, a case series published by Wang et al. (2024) showed promising results for cryoneurolysis as pain management after rib fractures. 

Other preliminary data suggest efficacy in pain control following total knee arthroplasty, rotator cuff injuries, limb amputations, and lower limb burn injuries. 

However, as previously mentioned, many studies are not the highest quality (lots of case reports and case series) and more research is needed. But, so far the results are promising!

What's the downside?

Because analgesia can be achieved for weeks-months, this modality is less useful for nerves that have both motor and sensory function, as it can impair someone's motor function for a long time. 

Other potential side effects are similar to those of nerve blocks, including bleeding, infection, and (longer than intended) nerve damage.

Also - this requires a specialized cryoneurolysis probe to do, so you'd potentially be limited by the resources of your practice setting.

Is this helpful for us in the ED?

Much of the literature that has come out about cryoneurolysis has been from our surgery and anesthesia colleagues. However, given that nerve blocks are becoming more and more common in EM (and certainly in the Maimo ED), doing ultrasound-guided cryoneurolysis can certainly be a pain control modality that EM providers can do. 

Given that a lot of what we see in the ED relates to pain, cryoneurolysis can be an additional pain control option for patients that require long-term pain control. Many of the studies are reporting multiple weeks of pain control after cryoneurolysis. If you're giving pain control after surgery or trauma, the hope is that maybe after the weeks of cryoneurolysis wear off, the patient's injury/surgery will have healed enough that their pain will be tolerable. 

Also, given the public health push to reduce routine opioid use, cryoneurolysis can aid us in providing another option to patients who are in pain. 

In conclusion...

Cryoneurolysis is an old technique that has newly become a feasible pain management option in the era of modern cryoneurolysis probes and ultrasound-guided nerve blocks. While more research is needed and more training is needed for EM providers, this may be an up and coming option for longer term pain management. 

References:

John J. Finneran IV & Brian M. Ilfeld (2021) Percutaneous cryoneurolysis for acute pain management: current status and future prospects, Expert Review of Medical Devices, 18:6, 533-543, DOI: 10.1080/17434440.2021.1927705

Cha PI, Min JG, Patil A, et al. Trauma Surg Acute Care Open 2021;6:e000690.

Finneran Iv JJ, Gabriel RA, Swisher MW, et al. Ultrasound-guided percutaneous intercostal nerve cryoneurolysis for analgesia following traumatic rib fracture -a case series. Korean J Anesthesiol. 2020;73(5):455-459. doi:10.4097/kja.19395

Gabriel RA, Seng EC, Curran BP, Winston P, Trescot AM, Filipovski I. A Narrative Review of Ultrasound-Guided and Landmark-based Percutaneous Cryoneurolysis for the Management of Acute and Chronic Pain. Curr Pain Headache Rep. Published online July 4, 2024. doi:10.1007/s11916-024-01281-z

Wang S, Earley M, Kesselman A, et al. Percutaneous Cryoneurolysis for Pain Control After Rib Fractures in Older Adults. JAMA Surg. Published online August 7, 2024. doi:10.1001/jamasurg.2024.2063

Ilfeld BM, Gabriel RA, Trescot AM. Ultrasound-guided percutaneous cryoneurolysis for treatment of acute pain: could cryoanalgesia replace continuous peripheral nerve blocks?. Br J Anaesth. 2017;119(4):703-706. doi:10.1093/bja/aex142