Archive | October, 2014

WWWTP #21… Answer

October 28, 2014

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This is an interesting X-ray of a newborn with respiratory distress:

WWWTP 21

WWWTP 20

 

The upper Chest X-ray has an endotracheal tube near the carina (probably should be pulled back a bit).  It also has cardiomegally with vascular congestion.  The line coming up from below is an umbilical venous catheter in the inferior vena cava.

The “baby gram” below shows the same.  This image gives a better view of the umbilical line.

An umbilical venous catheter should traverse as this one does.  It comes straight up from the umbilicus to just above the diaphragm near the right atrium and inferior vena cava junction.  If the catheter does not go straight up and veers to the left side of the patient, it may have erroneously entered the hepatic vasculature.  This can result in hepatic complications.

The patient ended up having a double outlet right ventricle (both the aorta and main pulmonary artery are attached to the right ventricle) which is one of many anatomic heart abnormalities that can lead to congestive heart failure.  There was also a patent ductus arteriosus and a large ventral septal defect (VSD) that allowed for mixing of deoxygenated and oxygenated blood.  Without the large VSD the patient would not have been able to survive.

Author:  Russell Jones, MD

 

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What’s Wrong With This Picture #21 (WWWTP?)

October 21, 2014

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This is an interesting X-ray of a newborn with respiratory distress:

WWWTP 21

WWWTP 21

 

What are the findings in this picture?

Answer to follow.

Author:  Russell Jones, MD

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Student Corner: Ottawa Ankle Rules

October 14, 2014

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The Ottawa Ankle Rules are a set of criteria that are designed to help clinicians identify which patients that present with acute ankle injuries require imaging. The 1992 paper which outlined the criteria (PMID:1554175) consisted of a prospective study of 750 patients who came into the Ottawa Civic and Ottawa General hospitals with acute ankle injuries. The study was designed to record each patient’s particular presentation (area of tenderness, amount of swelling, ecchymoses, etc) and see if any aspect of their presentation correlated with a fracture identified on subsequent imaging (i.e. if a patient has pain over the medial malleolus, how likely are images of that ankle to show a fracture?).

MD Calc has a good summary picture of the criteria here. I’ll summarize it below as well:

A series of ankle x-rays is necessary if:

There is tenderness in the malleolar zone (lateral or medial) AND bony tenderness at the posterior edge of the medial malleolus OR bony tenderness at the posterior edge of the lateral malleolus OR an inability to bear weight immediately and in the ED

OR

There is tenderness in the midfoot zone AND bony tenderness at the base of the 5th metatarsal OR bony tenderness at the navicular OR an inability to bear weight immediately and in the ED

The picture on the link above is probably more helpful to visualize the algorithm. They note that 102 patients out of the 750 cohort had “significant” fractures and these criteria would have led to imaging on all of those cases. Also, they report that this criteria would have led to a 32.3% decrease in the number of radiographs ordered. The algorithm’s sensitivity was 100% and specificity was 40% for identifying fractures that were later confirmed by imaging. In other words, it was touted as a great screening tool since it was highly sensitive in picking up an ankle fracture.

(Note: The original criteria included an age stipulation, so that every patient with ankle pain [but not midfoot pain] over the age of 55 was recommended to get imaging. Additional research and subsequent modification of the algorithm proved that age was actually not a predictive variable. [PMID: 8433468])

Now on to a case:

Homeless male, in his 50’s, with ankle and foot pain after falling 10 feet. Walked into the E.D. with some pain, but had the ability to bear weight. Pt had swelling on exam, but no tenderness at the lateral malleolus, medial malleolus, mid foot or lateral foot.

The question is, do you get imaging on this patient?

Oh, look, it turns out we have criteria for that! And, in short, if you follow the Ottawa Ankle Criteria, the answer is no. The patient can bear weight and has no tenderness at any of the 4 areas that the criteria specifies, therefore according to the algorithm, imaging should not be ordered.

But we have a twist! This patient did indeed get ankle x-rays.

Ottawa Ankle 1

Why did this patient end up getting ankle x-rays despite not having met the Ottowa Ankle criteria?

Dr. Jones plays “devil’s advocate” in arguing against the use of the Ottowa Ankle Rules:

“Despite high negative likelihood ratio’s found on creation and validation of the Ottowa Ankle Rules, ED physicians are still ordering x-rays for most traumatic ankle complaints.  Why?  Because they are immediately available, low cost, and low radiation.  Many of our radiology decision rules pertain to expensive tests that are 10-100 times the amount of radiation (CT head, CT c-spine) and/or may not be readily available.  It is less practical to try and decrease a test that has little downside…such as an ankle radiograph.  

There is usually significant comorbidity associated with many different types of ankle fractures including calcaneal and talar fractures (I mention these because in my experience these are the two fracture patterns that are missed by the Ottowa Ankle Rules despite their reported 100% sensitivity…see the case above).  In our medicolegal environment in the United States, it is very difficult to defend missing an ankle fracture when you have a low cost, low radiation, readily available test at your disposal.  One must take into account that it is nearly impossible to recreate an exam with our current medical documentation.  A radiograph is an objective picture of a non-fractured ankle while a nicely worded exam is not so defendable in the eyes of a layman jury.  You open yourself up to legal problems if you miss a high-morbitidy injury because you used a rule that “decreases medical costs and increases efficiency” (these are the main benefits of the Ottowa Ankle Rules).  Courts are more patient-centered, they don’t care about our waiting room times!

We practice medicine taking into account more than just evidence-based medicine.  Until the “standard of care” we are held up to in court is in line with evidence-based medicine, we will always have to take into account the burden of the medicolegal consequences.  Be careful utilizing any clinical decision rules until they are universally accepted as standard of care among all ED physicians.  

I personally use “shared decision making” with most of my decision rule utilization.  My practice pattern using Ottowa Ankle Rules involves (1) A medical record documenting negative Ottowa Ankle Rules AND (2) a patient that understands the decision not to x-ray AND (3) the patient agrees.  This situation is rare but I will sometimes not x-ray if all the above parameters are met.  This is easier to defend if you happen to miss something by not getting an x-ray.  

The above statement is of course my own opinion and practice pattern.  Please utilize the Ottowa Ankle Rules as you feel fit and I appreciate any comments for and against their use in the ED.    

Russell Jones, MD”

So, there you have it. As is the case with many different areas of medicine, real-life practice varies from guidelines, rules and algorithms (even if they are backed up by multiple research studies) for various different reasons which include, but are not limited to differences in: availability of testing methods, medical setting, hospital policies, patient needs, legal considerations and the physician’s own interpretation of all of the above factors and the medical research/literature.

For students, this means that you’ll have to soon adapt yourself to an environment and way of thinking that takes multiple variables into account when it comes to decision making. Almost every patient is a different shade of grey, not black and white. After all, medicine is both art and science.

But, I digress from the patient. Can you spot the fracture in the above image? Answer below:

Calcaneal fracture with arrow

 

There is indeed a fracture of the calcaneus right around the inferior edge of the bone. Good thing this patient got imaging, right?

Author: Jaymin Patel

References:

Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Worthington JR. A study to develop clinical decision rules for the use of radiography in acute ankle injuries. Ann Emerg Med. 1992 Apr;21(4):384-90. PubMed PMID: 1554175

Stiell IG, Greenberg GH, McKnight RD, Nair RC, McDowell I, Reardon M, Stewart JP, Maloney J. Decision rules for the use of radiography in acute ankle injuries. Refinement and prospective validation. JAMA. 1993 Mar 3;269(9):1127-32. PubMed PMID: 8433468.

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Back pain…

October 7, 2014

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Back pain is one of the most frequent complaints in the ED.  The vast majority of patients do not have a life threatening or highly morbid pathology.  Unfortunately, this patient did:

 

CT LSpine 1 LS spine 2

This is a CT scan under bone windows.  It shows erosive changes based around the L4-L5 disc, eroding into the inferior endplate of L4 and the superior endplate of L5. These findings are concerning for discitis-osteomyelitis. It is favored to have both acute
and chronic components.

Finding this pathology is somewhat like finding a needle in a haystack.  However, pay attention to signs such as fever, repeat ED visits without a firm diagnosis, focal weakness, and predisposing factors such as IV drug abuse, history of endocarditis, or immunosuppression.  Sedimentation rate and C-reactive protein are often elevated in this disorder (among others).

CT is a readily available, quick way to diagnose this pathology but it isn’t as sensitive as MRI.  Plain films are not reliable but may show changes similar to the CT above.  Nuclear medicine bone scans as well as PET scans can be used but are not commonplace in the ED.

Author:  Russell Jones, MD

Image Contributor:  Zachary Skaggs

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