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

POTD: What type of blood transfusion do I order?

This POTD was inspired by a CED that we recently did on a level 1 trauma in the ED. Special shout out to RN Mel Besett for answering some of my questions I had about this topic.

The trauma case went something like this...an EMS note was called, stating that a man had stabbed himself in the abdomen with a kitchen knife. He was tachycardic, BP was stable, GCS 15. 

When the patient arrived, he was noted to have HR of 120-130s, BP initially 130s systolic. eFAST positive for free fluid in the RUQ. Throughout the trauma, he remained tachycardic and his BP started to trend downwards - SBP 130s...then 120s...110s...100s. 

It was decided that the patient should receive a blood transfusion, but...what type of blood should we order? How emergent was this?

Let's dive into it. There's a few different types of blood transfusions we can initiate in the ED:

Regular, cross-matched blood:

- For patients who are stable enough to wait. Typically, with waiting for the T&S, requesting blood, and starting blood, this could take more than 1-2 hours. 

- Requires 2 type and screens in the chart - if patient has a previous one in their chart, you can order just 1 

- Blood transfusion consent on Taylor Health

Emergent blood:

- Can take 10-15minutes depending on if there is someone available to run to the blood bank and back. Otherwise, the blood bank will have to send the blood through the chute, which can also take around that amount of time

- Requires a "Emergency Blood Transfusion Request" on Taylor Health

- Also requires patient consent. If patient is unable to be consented, requires 2 attending consent. 

"Cracking the fridge":

- There is a fridge in resus 51 stocked with pRBCs, platelets, and plasma

- Charge RN has code to the fridge

- The fridge also has whole blood (which is all the elements combined), but only the trauma attending can call for whole blood from the fridge

Massive transfusion protocol (MTP):

- At least 6 units of blood, comes from the blood bank

- If starting MTP, typically we start giving units of blood from the fridge, then call for MTP from the blood bank 

To end the case, given the patient's BP was declining, he was taken emergently to the OR. Because the OR was ready and patient couldn't wait ~10-15 minutes for emergent blood to arrive, he received his first unit of blood from the fridge while being transported to the OR.