Hydronephrosis, stones and dispo

[roja]

Question:

You have a patient with a history of stones, hematuria and renal colic type pain. You have ruled out other abdominal pathology.


You do an ultrasound, how does the the presence or absence of hydronephrosis change your dispo. Or does it?

Do you CT all your repeat stones?

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[ckent]

Hydronephrosis should influence whether or not you want to page a urologist to get the stone out or whether or not you want to send the patient home or admit the patient to a medical service. My understanding is that hydronephrosis will lead to kidney failure, therefore, it's one of the indications to do some sort of intervention to get rid of the stone.

 

[peksi]

I generally use this approach to renal colic.

1- All first time renal colic gets a limited CT (standard of care in most EDs)

2- I will often do an ED US for hydro, renal contour, exclude single kidney etc.

3- UA is critical as UTI + stone/pyelo (IVABX/fluids+Admit) is not the same as UTI.

4- Hydro alone does NOT get one admitted. Renal colic and hydro are a result of obstruction (partial or complete) with elevated hydrostatic pressure from the ureteral stone, the majority of these pass on their own so most patients (prob 80%) or more need Urology follow up not admission. Almost every patient in your ED with renal colic has hydro...now are you admitting all these...I doubt it.

5- Patients I admit for stones are, refractory pain, persistent vomiting, stone +pyelo, stone w/single kidney etc. Degree of hydro actually plays little into my dispo. Patients walk around with 5,6 mm,even 10mm stones in the ureter. Some urologist take out right away, some do lithotripsy, some will wait a few days to see what happens andfollow the patient.

6- When using ED US for flank pain the #1 thing you need to do is r/o AAA!!! that is what will kill your patient fastest...then look at the kidneys.

7-As for chronic renal colic patients, I try to avoid multiple CT scans, these folks often get CTs at the drop of a hat and in 5-10 years could get 10, 20 or more CTs...not real good for cell division if you get my drift.

8- now if a patient w h/o stones has refractory pain, fever etc i will often re CT etc.

Key Focused ED Renal US issues:

Always veiw the entire kidney (masses, cysts tend to be at the inferior poles)
Evaluate the 4 Cs (renal Contrast, Contour, Collecting System, and Comparison kidney). Realize that the width of the US beam is about 1-1.5mm thick so you need to really scan through the kidney to visualize the entire kidney. Any findings should be verified in more than one plane.

Hope that helps,

Paul

 

[Sheerstress]

UA is critical as UTI + stone/pyelo (IVABX/fluids+Admit) is not the same as UTI

I've often been told that patients with a UTI and a hydroureter on U/S probably should be admitted, but no one's ever suggested why.

Recently, someone suggested to me that this patient would become septic quicker than they otherwise because the stone could potentially trap the infection proximal to the obstruction, allowing it to proliferate. Make sense?

 

[DrQuinn]

Also be sure that it is a good UA... a few leukocytes doesn't mean infection, you can get that from the inflammatory reaction... come on nitrates and bacteria!

Q, DO

 

[ckent]

Originally posted by Sheerstress
I've often been told that patients with a UTI and a hydroureter on U/S probably should be admitted, but no one's ever suggested why.

Recently, someone suggested to me that this patient would become septic quicker than they otherwise because the stone could potentially trap the infection proximal to the obstruction, allowing it to proliferate. Make sense?

My understanding is that it is because having an obstructed kidney will lead to loss of permanent loss of kidney function. Most people are fine with only one functioning kidney, but if he is a chronic renal stoner or he has CRI for whatever reason, he may need all the functioning kidney that he can get.

 

[docB]

So what's the consensus on starting your uncomplicated stones on antibiotics. I've heard everything from "Absolutely, it's a nidus for infection." to "Absolutely not, it's not indicated."

 

[ckent]

Originally posted by docB
So what's the consensus on starting your uncomplicated stones on antibiotics. I've heard everything from "Absolutely, it's a nidus for infection." to "Absolutely not, it's not indicated."

Well, I've never heard of empirically starting antibiotics for nephrolithiasis, particularly when the patient is afebrile and only has blood on urinanalysis. Other indications may be if you believe that you have a struvite kidney stone (eg if you see staghorn kidney stones), but even then I suspect that most ID docs would say that you would let the urinanalysis and clinical picture drive your decision. Antibiotics aren't always benign drugs to be starting, particularly when you are worried about impending kidney failure secondary to stones, it would stink to add on ATN to knock out whatever remaining kidney function the patient had.

 

[roja]

Originally posted by peksi
I generally use this approach to renal colic.

1- All first time renal colic gets a limited CT (standard of care in most EDs)

2- I will often do an ED US for hydro, renal contour, exclude single kidney etc.

3- UA is critical as UTI + stone/pyelo (IVABX/fluids+Admit) is not the same as UTI.

4- Hydro alone does NOT get one admitted. Renal colic and hydro are a result of obstruction (partial or complete) with elevated hydrostatic pressure from the ureteral stone, the majority of these pass on their own so most patients (prob 80%) or more need Urology follow up not admission. Almost every patient in your ED with renal colic has hydro...now are you admitting all these...I doubt it.

5- Patients I admit for stones are, refractory pain, persistent vomiting, stone +pyelo, stone w/single kidney etc. Degree of hydro actually plays little into my dispo. Patients walk around with 5,6 mm,even 10mm stones in the ureter. Some urologist take out right away, some do lithotripsy, some will wait a few days to see what happens andfollow the patient.

6- When using ED US for flank pain the #1 thing you need to do is r/o AAA!!! that is what will kill your patient fastest...then look at the kidneys.

7-As for chronic renal colic patients, I try to avoid multiple CT scans, these folks often get CTs at the drop of a hat and in 5-10 years could get 10, 20 or more CTs...not real good for cell division if you get my drift.

8- now if a patient w h/o stones has refractory pain, fever etc i will often re CT etc.

Key Focused ED Renal US issues:

Always veiw the entire kidney (masses, cysts tend to be at the inferior poles)
Evaluate the 4 Cs (renal Contrast, Contour, Collecting System, and Comparison kidney). Realize that the width of the US beam is about 1-1.5mm thick so you need to really scan through the kidney to visualize the entire kidney. Any findings should be verified in more than one plane.

Hope that helps,

Paul

Thanks alot for the response. The reason I am was asking is that I am doing research on the use of ultrasound for repeat stones. It has been suggested by many that hydro would help you decide ifyou wanted a repeat CT. (these are all on the assumption that UTI, AAA etc are not present).

It was confusing me that so many attendings want CT scans (I think in a CYA mode) on repeat stones. Especially as your point is underscored in urology texts. People walk around with giant stones all the time. And in individuals that have bilateral kidneys, as complications even from severe hydro are rare.

It seems to me to get pain control, hydrate (once life threating issues/infection are ruled out) and get follow up.

 

[DrQuinn]

Originally posted by ckent
My understanding is that it is because having an obstructed kidney will lead to loss of permanent loss of kidney function. Most people are fine with only one functioning kidney, but if he is a chronic renal stoner or he has CRI for whatever reason, he may need all the functioning kidney that he can get.

Having a hydronephrosis in and of itself does not lead to permanent kidney loss... if we had a post-renal obstruction, we would all develop hydronephrosis, and it woudl resolve once the obstruction left. In fact, most of the people that I've seen this year with nephrolith have some degree of hydronephrosis.

Q, DO

 

[peksi]

From my fellowship days.

Does the Presence of Hydronephrosis on Emergency Department Renal Ultrasounds Predict the Presence of Renal Calculi?
Paul R Sierzenski, Michael Blaivas, Pamela S Laesch, George Keng and Michael J Lambert

Christiana Care Health System: Newark, DE, North Shore University Hospital: Manhasset, NY, Christ Hospital and Medical Center: Oak Lawn, IL

ABSTRACT

Objective: To determine if the presence of hydronephrosis on emergency department (ED) renal ultrasound (RUS) correlates with the presence of a renal calculus (RC) in patients presenting with renal colic. Methods: We conducted a retrospective chart review of ED ultrasound logs from 12/23/98 to 12/1/99 at a community teaching hospital with an emergency medicine residency program and an annual census of 65,000 visits. Records for all patients having an ED RUS during the above dates were reviewed. Data including the presence, absence, and degree (mild, moderate, or severe) of hydronephrosis were recorded. Results of spiral computed axial tomography scans and intravenous pyelograms were reviewed. The results of these studies, including the presence of a RC, and calculus size were recorded. Calculi were categorized as 5.0 mm, 5.1-7.9 mm, or 8.0 mm. Sensitivity and specificity, 95% confidence intervals, and positive and negative predictive values were calculated. Results: 233 patients were identified by ED US logs. 107 patients (46%) had a formal radiological study during their ED visits. 65 patients were diagnosed as having hydronephrosis (33 mild, 31 moderate, and 1 severe) by ED RUS. 27 of 65 (41%) patients with hydronephrosis failed to demonstrate a RC on formal radiological evaluation. 13 of 51 (25%) patients with a documented RC did not demonstrate hydronephrosis. 38 of 65 (75%) patients with hydronephrosis had a demonstrated RC. No significant correlation existed between the degree of hydronephrosis and renal calculus size. Positive and negative predictive values were 58% and 69%, respectively. The specificity was 52% (95% CI 0.39 to 0.65), while the sensitivity was 75% (95% CI 0.59 to 0.83). Conclusions: In our study no significant correlation existed between the presence or the degree of hydronephrosis on ED RUS, and the size of the renal calculus. Emergency physicians should keep in mind that sensitivity of hydronephrosis for detecting a renal calculus in this study was 75%.


Paul

 

[DrQuinn]

Interesting study! Thanks.

Q, DO

 

[roja]

Originally posted by peksi
From my fellowship days.

Does the Presence of Hydronephrosis on Emergency Department Renal Ultrasounds Predict the Presence of Renal Calculi?
Paul R Sierzenski, Michael Blaivas, Pamela S Laesch, George Keng and Michael J Lambert

Christiana Care Health System: Newark, DE, North Shore University Hospital: Manhasset, NY, Christ Hospital and Medical Center: Oak Lawn, IL

ABSTRACT

Objective: To determine if the presence of hydronephrosis on emergency department (ED) renal ultrasound (RUS) correlates with the presence of a renal calculus (RC) in patients presenting with renal colic. Methods: We conducted a retrospective chart review of ED ultrasound logs from 12/23/98 to 12/1/99 at a community teaching hospital with an emergency medicine residency program and an annual census of 65,000 visits. Records for all patients having an ED RUS during the above dates were reviewed. Data including the presence, absence, and degree (mild, moderate, or severe) of hydronephrosis were recorded. Results of spiral computed axial tomography scans and intravenous pyelograms were reviewed. The results of these studies, including the presence of a RC, and calculus size were recorded. Calculi were categorized as 5.0 mm, 5.1-7.9 mm, or 8.0 mm. Sensitivity and specificity, 95% confidence intervals, and positive and negative predictive values were calculated. Results: 233 patients were identified by ED US logs. 107 patients (46%) had a formal radiological study during their ED visits. 65 patients were diagnosed as having hydronephrosis (33 mild, 31 moderate, and 1 severe) by ED RUS. 27 of 65 (41%) patients with hydronephrosis failed to demonstrate a RC on formal radiological evaluation. 13 of 51 (25%) patients with a documented RC did not demonstrate hydronephrosis. 38 of 65 (75%) patients with hydronephrosis had a demonstrated RC. No significant correlation existed between the degree of hydronephrosis and renal calculus size. Positive and negative predictive values were 58% and 69%, respectively. The specificity was 52% (95% CI 0.39 to 0.65), while the sensitivity was 75% (95% CI 0.59 to 0.83). Conclusions: In our study no significant correlation existed between the presence or the degree of hydronephrosis on ED RUS, and the size of the renal calculus. Emergency physicians should keep in mind that sensitivity of hydronephrosis for detecting a renal calculus in this study was 75%.


Paul

Thanks for the abstract.

 

[roja]

As i have progressed through the literature, I have begun to scratch my head a little. (not quite as confused as pediatric fever..)


but it begs the question, does one need to see a stone to diagnos renal colic??????????

 

[peksi]

Ahh yes, the need for definitive identification of pathology this is what every patient demands right.

Well, that is not really the duty of an EM physician in my mind, the field and the government mandate that EM exclude "life and limb threatening conditions". Most patients do not realize that this is our job...not to answer every queation. Often we get the answer in the time we have. Sometimes we call in a consultant for assistance, sometimes we admit the patient for further w/u when we are concerned about significant unidentified pathology that cannot have op w/uor for further treatment. of course I treat when needed etc.

Well doctor you are right! you do NOT need to see a stone to diagnose "renal colic" as this decribes the symptom of waxing waining pain usually from renal obstruction, partial or complete. Several things can cause this, stones, masses, ureteral reflux, even MS can result in reflux and "colic". Now we come to the CYA that you have mentioned. in summation patients who have known renal colic, seen urology etc, when they present with renal colic I treat them as such often times without imaging, usually an ED US, and if i'm concerned about other issues then start the search. I do not CT all my repeat stones, as a matter of fact less than 1 in 5 will i repeat scan unless the situations as i previously stated arise.


Paul

 

[roja]

Originally posted by peksi
Ahh yes, the need for definitive identification of pathology this is what every patient demands right.

Well, that is not really the duty of an EM physician in my mind, the field and the government mandate that EM exclude "life and limb threatening conditions". Most patients do not realize that this is our job...not to answer every queation. Often we get the answer in the time we have. Sometimes we call in a consultant for assistance, sometimes we admit the patient for further w/u when we are concerned about significant unidentified pathology that cannot have op w/uor for further treatment. of course I treat when needed etc.

Well doctor you are right! you do NOT need to see a stone to diagnose "renal colic" as this decribes the symptom of waxing waining pain usually from renal obstruction, partial or complete. Several things can cause this, stones, masses, ureteral reflux, even MS can result in reflux and "colic". Now we come to the CYA that you have mentioned. in summation patients who have known renal colic, seen urology etc, when they present with renal colic I treat them as such often times without imaging, usually an ED US, and if i'm concerned about other issues then start the search. I do not CT all my repeat stones, as a matter of fact less than 1 in 5 will i repeat scan unless the situations as i previously stated arise.


Paul

I agree. The frustration I encounter from some of my friends in other fields is the misconception that it is the job of the Ed to diagnos the patient. While this does often happen, it is not the primary role of the ED. As you said, it is to rule out life threatening events, determine who needs to come in to the hospital or what consultants might be needed.

The research I have encountered on stones seems to all point to the fact that the stone does not need to be visualized to diagnos stones. In fact, a number of individuals seem to advocate not imaging first time stones. Especially in clear cases where AAA and pyelo are not an issue.

It seems reasonable that close urology follow up to ensure passage of stone or contact in case the stone is not passing, with analgesia and hydration are adequate. There just doesn't seem to be a consensus.

 

[peksi]

Well you an I agree, I'll get one more and we'll have a consensus.

Paul

 

[roja]

Originally posted by peksi
Well you an I agree, I'll get one more and we'll have a consensus.

Paul

I don't think a PGY1 counts as a whole. You migt need to find 1.5 for that concensus. 🙂)

 

[mikecwru]

From my limited experience, we get CTs on older people and sometimes young people with weird stories. I've been taught the role of the CT besides seeing the stone is to make sure the aorta is ok. Secondly, I've also been taught that hydronephrosis is not immediately threatening to the kidney. The fear is renal failure from obstruction but I've been told that is a complication of several weeks. After consulting urology here, I've sent people home with stones and UTIs on po abx and close urology f/u. So I don't think a stone, regardless of size, and an infection automatically buys you a bed.

mike

 

[Sessamoid]

The feeling I get from private urologists is that obstruction doesn't buy you an admission. An obstruction with an infection might buy you an admission, if you're really sick (especially if you're insured in a fee-for-service model). With oral quinolones, as long as you're stable and can get good followup, there's really no benefit to in-patient care versus outpatient.

Personally, I image all first-time flank pains, though I don't necessarily think you have to. I've caught a few weird diagnoses (i.e. tumors) this way that would otherwise have been sent home as presumptive renal stones.

 

[DrQuinn]

*sigh*

hearing all this EM talk going around makes me miss the ED... damn off-service rotations.

J/K.

In what other specialty can I have 15 minutes of fun (intubating 15 people), then go home and play Unreal Tournament (or... *sigh* read). Gotta love the anesthesia month.

Q, DO

 

[roja]

Originally posted by QuinnNSU
*sigh*

hearing all this EM talk going around makes me miss the ED... damn off-service rotations.

J/K.

In what other specialty can I have 15 minutes of fun (intubating 15 people), then go home and play Unreal Tournament (or... *sigh* read). Gotta love the anesthesia month.

Q, DO

I start anesthesia on monday and am looking forward to a little free time. 🙂 Course, is cold as anything here but still, cushy off service month is a cushy off service month.


Of course, given my slight ADD tendencies, I have already sceduled research meetings etc and ultrasound time in the ED.


I think I might have picked the right field finally. *g*