CT for all kidney stones?

[12R34Y]

Earlier thread brought this up......

I'm kind of sick of scanning every 30 y/o with "I have another kidney stone." Not only do I think I'll eventually give him his radiation induced cancer, but I'd rather just treat his pain, make sure its not infected, and have him follow up with urology if pain controlled.

It seems like culture/standard here is to scan every freakin' stone pain that comes in.

I don't care if it is 1mm or 9mm. If its 1mm it passes and treatment is pain control.

If its 9mm it most certainly won't pass........I still don't care.........treatment is pain control and urology follow up for stent/litho/retrieval whatever as outpatient.

thoughts?

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[ERNerd]

I agree, and this is becoming my practice. Everything has to line up perfectly, though: Pt with h/o CT-proven stone in the past, comes in with exactly the same Sx as last time, has blood in the urine and no abdominal tenderness. When all of these factors fall into place (which, surprisingly, they often do), then I think CT scanning is silly. The only counter-argument I can think of is that getting the scan gives you some idea of the probability that the stone will pass on its own, but as far as I'm concerned, that little nugget of information is not worth the cost and radiation risk.

 

[southerndoc]

If they have blood in the urine, I treat them as if they have a stone if the symptoms fit. I do NOT routinely scan patients unless they're having difficulty with pain control or they choose to get a CT scan.

I inform every patient of the radiation exposure of scanning, that scanning often won't change management in the majority of cases, and that we will treat with pain control and will perform CT scan in the future if pain isn't controlled. That would signify a large stone that might need intervention, but the majority of stones pass without a problem. If the patient then chooses to have a CT scan, I order it.

Of course if they take more than 2 mg of Dilaudid to get pain control, then I scan. If they have a history of large stones requiring intervention, then I scan unless they've had 30 scans.

 

[po' boy]

What's the purpose of a CT scan in kidney stones? To determine the size of the stone? Not really. It's to rule out hydro/obstruction.

As previously mentioned, if a patient's writhing in pain despite aggressive pain control attempts, a scan's worth it. Also for septic looking patients with fever, abnormal creatinine, or infected urine. But more often than not, a simple bedside ultrasound to rule out calyceal dilatation will give you the same info as the scan. Who cares about the size of the stone, it's whether it's obstructing or causing uncontrollable pain that's the issue -- then it needs to come out and the patient gets a bed. Otherwise it's all the same -- pain and nausea control, antiinflammatories, hydration, medical expulsive therapy with flomax (or other med of choice), and urology follow up. And a strainer. (Preferably not the ED coffee filter)

 

[southerndoc]

Wait, are you saying you admit all obstructive stones?!?

Even during residency we didn't do that. Your urology guys must be pretty aggressive there.

 

[Jeff698]

What's the purpose of a CT scan in kidney stones? To determine the size of the stone? Not really. It's to rule out hydro/obstruction.

And rule out alternative dx. Like AAA or appy.

I generally avoid repeat scans if I think the dx is clear. I get a UA and Cr, pain control then Rx vicodin and flomax with PCP f/u unless complicated, then urology f/u.

Take care,
Jeff

 

[ERNerd]

What's the purpose of a CT scan in kidney stones? To determine the size of the stone? Not really. It's to rule out hydro/obstruction.

As previously mentioned, if a patient's writhing in pain despite aggressive pain control attempts, a scan's worth it. Also for septic looking patients with fever, abnormal creatinine, or infected urine. But more often than not, a simple bedside ultrasound to rule out calyceal dilatation will give you the same info as the scan. Who cares about the size of the stone, it's whether it's obstructing or causing uncontrollable pain that's the issue -- then it needs to come out and the patient gets a bed. Otherwise it's all the same -- pain and nausea control, antiinflammatories, hydration, medical expulsive therapy with flomax (or other med of choice), and urology follow up. And a strainer. (Preferably not the ED coffee filter)

Aren't almost all symptomatic stones obstructive to some degree? (And conversely, aren't almost all nonobstructive stones, e.g., in the renal parenchyma, asymptomatic?) Isn't there almost always some degree of hydronephrosis when there's a stone in the ureter? The finding, whether on US or CT, helps to make the diagnosis, but I've never admitted a patient based on hydronephrosis alone, nor have I seen consulting urologists get too excited about it. Obstructive stones usually pass.

What I've seen is, almost regardless of the size of the stone, if the patient's pain and nausea can be controlled, and if there are no other complications (such as infection), urology wants the patient discharged with outpatient follow-up. And if there are complications, they just say admit to Medicine, but that's another issue...

 

[po' boy]

Aren't almost all symptomatic stones obstructive to some degree? (And conversely, aren't almost all nonobstructive stones, e.g., in the renal parenchyma, asymptomatic?) Isn't there almost always some degree of hydronephrosis when there's a stone in the ureter? The finding, whether on US or CT, helps to make the diagnosis, but I've never admitted a patient based on hydronephrosis alone, nor have I seen consulting urologists get too excited about it. Obstructive stones usually pass.

What I've seen is, almost regardless of the size of the stone, if the patient's pain and nausea can be controlled, and if there are no other complications (such as infection), urology wants the patient discharged with outpatient follow-up. And if there are complications, they just say admit to Medicine, but that's another issue...

sure, agreed. not all hydro comes in, it's all about the overall clinical picture. also, a CT may be useful to rule out other pathology such as appy etc., but without contrast is likely to be suboptimal for ruling out those other things. i haven't had a case in recent memory where i did the scan without suspecting appy versus stone and used the scan to make the diagnosis. the other clinical clues, history, UA and abdominal exam usually lead me to suspect one versus the other. bottom line is that the scan rarely changes my management with regard to admit or discharge. i've often made that decision well beforehand.

 

[xaelia]

And CT does tend to pick up that pesky leaking AAA in those other hematuria and belly pain patients....

At least on Board Review questions.

 

[kungfufishing]

I idealistically avoid them but realistically it seems like i get them at least 80% of the time. Well, maybe not quite that high. If you've had stones and this sounds like a stone and you aren't infected we're probably done if I can get your pain controlled. However, it seems like a lot of the time the folks who I see with stones have a history of stones requiring lithotrypsy or retrieval or are diabetic or are in severe pain or are actually just showing up because it feels like it hasn't passed in 5 or 6 days or have sx somewhat concerning for appendicitis.

 

[Old_Mil]

And rule out alternative dx. Like AAA or appy.

...or drug seeking. A urologist I know caught a drug seeker with "hematuria" when he noticed that he came out of the bathroom with a bloody urine specimen - and a bandaid he wasn't wearing when he went in to collect the specimen.

 

[Seaglass]

And CT does tend to pick up that pesky leaking AAA in those other hematuria and belly pain patients....

At least on Board Review questions.

So will bedside US. (at least it will pick up the AAA. You assume it's leaking if the patient is symptomatic)

 

[DrMom]

...or drug seeking. A urologist I know caught a drug seeker with "hematuria" when he noticed that he came out of the bathroom with a bloody urine specimen - and a bandaid he wasn't wearing when he went in to collect the specimen.

I've had one of these. Attending gave them the option of a new observed voided specimen (pt told that if + would get pain meds) or leaving. New specimen had no blood.

 

[roja]

I rarely scan for stones classic stone presentations in hemodynamically stable non-pregnant patient for whom AAA is not top3 in my diff dx:

One kidney
fever
signs of infection on ua
intractable pain after 2 rounds of appropriate analgesia (nsaid plus a real doses of narcotics, not 2mg of morphine)

Based on exhaustive review of literature. I think I offered up the literature summary I did for faculty development last year. I will offer it up again if anyone is interested.

 

[12R34Y]

I rarely scan for stones classic stone presentations in hemodynamically stable non-pregnant patient for whom AAA is not top3 in my diff dx:

One kidney
fever
signs of infection on ua
intractable pain after 2 rounds of appropriate analgesia (nsaid plus a real doses of narcotics, not 2mg of morphine)

Based on exhaustive review of literature. I think I offered up the literature summary I did for faculty development last year. I will offer it up again if anyone is interested.

I'd love to see the literature review!

 

[It'sElectric]

One attending's advice to me was that he typically scans those with first time stones and any stone that has been refractory to pain/nausea control (this is all assuming the clinical picture is classic for a stone).

I'm still surprised by the number of people I've seen (merely an M4) scanned for what appears to be a textbook stone. Obviously, I'll probably view things differently when it's my license on the line.

 

[roja]

I'd love to see the literature review!

send me a pm with an email addy and I will forward on.