Our goal is to provide you with a series of SOF-focused and case-based ultrasound education TiDBiTS. We want to show you how ultrasound can help you solve a number of operational and clinical dilemmas, especially in prolonged field care settings. Tidbits are defined as small and particularly interesting pieces of information, hence brevity is intentional!
Now, let me begin by saying that MARSOC guys are tough dudes – no doubt about that! This case is a tribute to their educational aspirations in point-of-care ultrasonography – and for this very reason our patient is a MARSOC operator – one of their very own! It’s an honor to count them in as my students!
A 35-year-old United States Marine Corps Forces Special Operations Command (MARSOC) Operator presenting with SEVERE RiGHT FLANK PAIN, NAUSEA & VOMiTiNG. The patient alerted the medic at the village stability platform clinic, where the team is in an austere prolonged field mission. The patient reports sudden ONSET of progressively worsening flank pain starting 2 DAYS AGO. There was NO PRECEDiNG TRAUMA. He is nauseated and has had multiple episodes of nonbloody nonbilious emesis. He has limited oral intake due to nausea. Patient further admits to iNCREASED URiNARY FREQUENCY & DYSURiA.
He denies any allergies, he does not take any medications, and he does not endorse any significant past medical or surgical history. In other words: a heck of a healthy guy!
His initial vitals:
- Heart rate: 125 beats/min
- Blood pressure: 105/65mmHg
- Respiratory rate: 24/min
- SpO2: 98% on room air
- Temperature: 38.5°C (101.3°F).
As part of your work-up, you obtain a right upper quadrant (RUQ) ultrasound with the findings as shown in the image below.
- What is the most significant finding?
- How does it influence the patient’s disposition in a forward deployed environment with limited evacuation potential?
Before we move on to discuss the sonographic findings, let us think clinically at first. As always, in the emergency and acute care settings, you have to reconcile the most likely with the most deadly. And this can prove pretty challenging in your resource-constrained environment.
So let’s consider the DDx for an otherwise healthy, young febrile male with atraumatic severe right flank pain, nausea, vomiting, dysuria and increased urinary frequency?
- Urinary tract causes: pyelonephritis, (obstructing) ureterolithiasis (= ureteral stone), cystitis
- Gastrointestinal tract causes: cholecystitis, pancreatitis, appendicitis
- GU causes: testicular torsion, epididymitis, orchitis
- A number of other much less likely causes that are intentionally omitted
Now let’s add a few clinical exam findings:
- Vitals as mentioned above
- Non-toxic appearing, dry mucous membranes
- Significant right CVA (costovertebral angle) tenderness
- The rest of your head-to-toe clinical exam is unrevealing
Putting it all together, upon thorough consideration you conclude that urinary tract causes are the most likely suspects. You dip the urine and it turns out to be infected. You already know it’s not a simple cystitis given your patient has right CVA pain + tenderness. Now here is this million dollar question in your “middle-of-nowhere-no-easy-MEDEVAC-land”: is it “just” pyelonephritis or does he have an obstructing stone in his ureter?
Now why is that so important?
Speaking hypothetically… You are caring for an otherwise healthy and non-toxic appearing young patient. If “all” he has is pyelonephritis, and you can’t ship him off right away, IV antibiotics (+ fluids) could potentially decrease the urgency or even obviate the need for an evacuation.
Things are entirely different if your patient has an obstructing ureteral stone on top of urinary tract infection and fever. This is an indication for an emergent urological intervention (decompression), and evacuation is necessary.
Now what does ultrasound have to do with all that?
SONOGRAPHiC MiSSiON SUPPORT
Ultrasound is the very tool you need to diagnose ureteral obstruction with the resultant HYDRONEPHROSiS. It is the key finding on our patient’s RUQ scan. The severity of hydronephrosis can be graded from MiLD through MODERATE to SEVERE, but keep in mind that the stone size does not correlate with the degree of hydronephrosis (1). Nevertheless, if hydronephrosis is less severe, your patient is less likely to have a large stone (2).
In our particular case, the degree of hydronephrosis is not that important, as it does not change your patient’s disposition in a forward deployed setting. Once again – presence of hydronephrosis (indicative of ureteral obstruction) in the setting of fever and infected urine is an indication for an emergent decompression, and your patient needs to be evacuated.
Now if you happen to care for a patient with suspected renal colic (without fever or UTI), and your patient does not have hydronephrosis, know that (s)he has a very low risk of needing a urological intervention (3).
Let us also share a little trick of the trade. If you think that your patient has very mild hydro, place a color Doppler gate over that area, so you don’t mistake renal vessels for hydronephrosis. Renal vasculature has color flow while hydronephrosis does not.
And last but not least… When in doubt over your patient’s disposition, or unsure about your ultrasound findings, never hesitate to request a TELE-MEDiCiNE CONSULT. Your consultant can help you obtain diagnostic images, interpret the images you have already obtained, and assist you with the clinical decision-making process that follows!
YOUR TURN: take a look at the following 4 clips and try to determine whether hydronephrosis is present or not?
Now you can check the answers at the end of this post! I bet you got them right!
YET ANOTHER CASE!
- Calabro JL, Raio CC, Theodoro D, et al. Does kidney stone size correlate with degree of hydronephrosis on focused emergency department ultrasonography? Ann Emerg Med. 2004;44:S114.
- Goertz JK, Lotterman S. Can the degree of hydronephrosis on ultrasound predict kidney stone size? Am J Emerg Med. 2010;28:813-6.
- Yan JW, McLeod SL, Edmonds ML, Sedran RJ, Theakston KD. Normal renal sonogram identifies renal colic patients at low risk for urologic intervention: a prospective cohort study. CJEM. 2015;17:38-45.
- CASE A – hydronephrosis (moderate to severe)
- CASE B – hydronephrosis (mild)
- CASE C – hydronephrosis (mild to moderate)
- CASE D – NO hydronephrosis
If you have any questions, concerns or educational needs, don’t hesitate to get in touch with our team!