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Likelihood Ratio (LR) in Emergency Medicine

12/08/2012

Atypical or typical, is this the question?



Clinical Scenarios

It is a busy day in your ED:




A 60 y/o female refers a retrosternal pain radiates to right arm that lasts more than 20 minutes. 

A 50 y/o male refers a pressure  in his chest, with tachycardia and sweating.

A 75 y/o female refers a sharp and stabbing pain exacerbates by forceful breathing.

In all cases the ECGs are nondiagnostic.
Do these clinical features help to predict an acute myocardial infarction (AMI)?


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11/17/2012

Pleuritic Pain, the end of the saga...





Clinical Scenario

A 33 y/o woman, comes to the ED because of a sudden emithorax pain on the left in basal region. The pain is described as stabbing, well localized, it worsen with inspirium …a pleuritic pain, no cough, no fever, not hemoptysis. She smokes, she does not take any medication. 
Chest x ray is normal. You receive blood test: WBC 7.500/mcL, CRP 20 mg/dl , D-dimer 603 ng/ml

We have seen in the previous post that we can’t rule out the possibility to find a radio-occult lesion based on our blood test, but on the other hand specificity is poor, so what are we looking for?
What does pleuritic pain means? 
If you ask wikipedia… the answer is frightful…


What if you ask to your probe?

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10/31/2012

Can we fight against Pulmonary Embolism using the LR’s arrows?


Clinical Scenario

A 80 y/o woman presented to the ED for dyspnoea.
She underwent a knee replacement 2 weeks ago, RR is 24, O2 saturation is 88%. HR is 90, the knee is edematous.
You are going to hunt a pulmonary embolism (PE)
While you phone the radiologist for a thorax CT scan you have an idea:




Can a compression ultrasonography (CUS) helps to avoid a CT?

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10/27/2012

What does it hide behind a negative X-Ray?


Clinical Scenario

A 33 y/o woman, comes to the ED because of a sudden emithorax pain on the left in basal region. The pain is described as stabbing, well localized, it worsen with inspirium …a pleuritic pain, no cough, no fever, not hemoptysis. She smokes, she does not take any medication. 
Chest x ray is normal. You receive blood test: WBC 7.500/mcL, CRP 20 mg/dl , D-dimer 603 ng/ml.



Maybe is not a wall chest pain, but in which direction this test are carrying you?


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10/11/2012

Pleuritic pain and radio-occult lesion

Clinical Scenario

A 33 y/o woman, comes to the ED because of a sudden emithorax pain localized on the left in basal region. The pain is described as stabbing, well localised, it worsen with inspirium …a pleuritic pain, no cough, no fever, not hemoptysis. She smokes, she does not take any medication. Chest x ray is normal. 


Is it a wall chest pain or there migth be something else? 


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10/04/2012

Does procalcitonin have a role in the management of acute appendicitis?


Clinical scenario
A 18 yo man comes to the ED in the morning because of low abdominal pain, fever and nausea. At palpation there is mild pain in the right inferior quadrant, not guarding.




Could procalcitonin (PTC) helps to exclude quickly an acute appendicitis?

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9/07/2012

Is cervical spine X-ray necessary if there is a distracting injury?

Clinical Scenario
 A 40 yo lady arrives in ED by ambulance with neck and spinal immobilization because she fell down a staircare.

 The patients vital signs are within normal physiological parameters, she is alert, no deficit, remembers all, denies head contusion and neck pain. She complains for a sharp shoulder pain (NRS 10/10), it seems broken.
If I perform the Nexus C-Spine criteria  X Ray is indicated: a distracting injury mandates cervical spine imaging.

How much the presence of distracting injury reduces my sensibility in rule out cervical spine (c-spine) injury?

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8/20/2012

Cellulitis and the role of laboratory


Clinical Scenario

A 72 y/o woman presented to the ED for swollen and painful leg.
Physical examination shows an erythematous, tender and warm leg. 
Probably it is a cellulitis. 
In previous post we stressed the US use to increase diagnostic accuracy. 



Can WBC or CPR help in the differential diagnoses?  
Do they have a role in the decision to admit the patient to the Hospital?  


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7/21/2012

Goodbye nasogastric lavage!


Clinical Scenario

A 84 yo woman arrives in ED in midnight coming from a nursing because of a reported episode of coffee ground vomiting. 
Respiratory rate, heart rate and blood pressure are normal, abdomen is not distended, hemoglobin level is 10 g/dl. On rectal examination you find normal stool. 
She takes warfarin. 


Can a nasogasric lavage (NGL) contribute to rule out an upper gastrointestinal bleeding (UGB)? 

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7/11/2012

Can Ultrasound rule out a pneumothorax?





Clinical Scenario

You are allerted for a level 3 trauma from the mountain, a cyclist has fallen going down hill.
You prepar the shock room with everything you may need, dress up, and wait.
A 25 y/o cyclist arrives completely immobilized, you immidiately start to  perform ABCDE as you learned in your recent ATLS course (you feel confident).
First stop is a possible problem in “B” (breathing): he has an ecchimosis on the right emithorax, not crepitation, maybe there is a less vescicular murmur on the same side, but you are not sure (the shock room is very crowded an noisy!), he is slightely tachypnoic (RR is 24), O2 saturation is 96%. …you go on….in “E” (Exposure) you find an exposed, bleeding, thigh bone fracture that surly is going to need surgery, at the moment you stop the bleeding, stabilize, allert orthopedic…ect…
FAST is normal. You ask for X-Ray : anteroposterior (AP) chest x-ray, pelvis and thigh bone. Confirmed exposed fracture, no signs of pneumothorax, surgery room is ready…
You recently have reeded the previous post and you don't feel confident about a negative thorax x ray, so you decide to “extend” your FAST and on the right emithorax you find a "lung point"...


are you going to let this patient be intubated?


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7/02/2012

Thoracic trauma and chest X-Ray


Clinical Scenario

You are alerted for a level 3 trauma coming from the mountain, a cyclist has fallen going down hill.
You prepare the shock room with everything you may need, dress up, and wait.
A 25 y/o cyclist arrives completely immobilized, you immediately start to  perform ABCDE as you learned in your recent ATLS course (...you feel confident).
First stop is a possible problem in “B” (breathing): he has an ecchimosis on the right emithorax, not crepitation, maybe there is a less vescicular murmur on the same side, but you are not sure (the shock room is very crowded an noisy!), he is slightely tachypnoic (RR is 24), O2 saturation is 96%. …you go on….in “E” (Exposure) you find an exposed, bleeding, thigh bone fracture that surly is going to need surgery, at the moment you stop the bleeding, stabilize, allert orthopedic…ect…
FAST is normal. You ask for X-Ray: anteroposterior (AP) chest x-ray, pelvis and thigh bone. Radiologist confirms exposed fracture, no signs of pneumothorax, surgery room is ready...


…Do you still feel confident?

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6/28/2012

Chest X-Ray and aortic dissection

Clinical Scenario 
A 70 yo man come to the ED for restrosternal chest pain and shortness of breath during minimal activity in the last days. He is an ex smoker, with a history of hypertension. On physical examination the patient is not in distress, with a regular blood pressure and regular oximetry. ECG shows no evidence of ischemia. You first think about coronary artery disease, but you also want to exclude an aortic dissection. In Radiology the patient remaine seated and receive an anteroposterior (AP) chest Xray: maximal mediastinal width (MW) is 8,80 cm (the optimal cutoff level is 8,65 cm), no other signs. 


Shall you worry?

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5/28/2012

Is CRP correlated to CT result in the evaluation of abdominal pain?


A 74 yo/man complained of diffuse abdominal pain. The pain was intermittent and accompained by vomiting. He has no history of abdominal pain or abdominal surgery.
On examinations the patient presented non icteric, afebrile, not tachicardic. 
The abdomen was mildly distensed with midline tenderness. 
The US evidenced a normal aorta diameter. 
Abdominal x ray showed non specific bowel gas pattern. 
CRP value was 7 mg/L.


The radiologist says it is a little value to perform an abdominal CT, we see tomorrow…..

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5/01/2012

How LR works. Why any test is unnecessary for a patient with very low-risk chest pain ?

A 40 yo truck driver, presented in ED with substernal chest pain. He is healthy, no family history of CAD. Held for observation, serial ECG have not modified, not elevated troponin.






Is an Exercise Treadmill Testing useful (ETT)? Or a Myocardial Perfusion Imaging (MPI) is better ?

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4/15/2012

Does Murphy’s sign and sonographic Murphy sign have the same clinical utility?

A 40 yo woman presented to the ED with upper quadrant pain since three hours after eating a tasty pizza. She is overweight, she presents feverish (38°C) her skin is nonicteric. The abdomen is soft, there is tenderness on the upper right quadrant, you perform a deep palpation in the subcostal area, and the patient stops breathing for pain. 




Is Murphy’s sign useful to make diagnosis of cholecystitis? What about the sonographic Murphy’s sign?

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4/05/2012

Diagnosis of pneumonia. Is it the time for a combined imaging strategy?

A 80 yo man is brought from an assisted-living facility because of fever, productive cough, tachycardia and dyspnoea. 
He has a history of dementia and hypertension.
He is cachectic, you hear ronchi on the left side. 



How should you approach this patient?

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3/18/2012

Rectal Examination and Appendicitis

A 25 y/o man comes to the ED because of abdominal pain started 2 hours before, fever and vomit.
He has not history of disease, no history of surgery, no history of other ED admission for abdominal pain.
Clinical examination shows rigidity and diffused painfull abdomen.




You perform digital rectal examination were you evidence no pain in the Douglas space and normal stool, can you exclude appendicitis?.







Conclusion 

Digital rectal examination (DRE) is not necessary in patients with suspected acute appendicitis, it provides no additional information that is not available on the abdominal examination.
It is not useful in comparison with the discomfort and privacy problems that often accompany its use, it can be very unpleasant for the patient. 
There is also poor evidence regarding the clinical utility of the DRE in the diagnosis of undifferentiated abdominal pain.


Bibliography 

R. E. B. Andersson
Meta-analysis of the clinical and laboratory diagnosis of appendicitis
British Journal of Surgery 2004; 91: 28–37

J Quaas , M Lanigan, D Newman, J McOsker, R Babayev, C Mason
Utility of the digital rectal examination in the evaluation of undifferentiated abdominal pain
American Journal of Emergency Medicine (2009) 27, 1125–1129

S A Colucciello, T W Lukens, D L Morgan 
Assessing Abdominal Pain In Adults: A Rational, Cost-Effective, And Evidence-Based Strategy
Emergency Medicine Practice, Premier Issue Volume1,Number1, 1999

N Manimaran, RB Galland
Significance of routine digital rectal examination in adults presenting with abdominal pain
Ann R Coll Surg Engl 2004; 86: 292–295






Ilenia Spallino
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2/10/2012

Bowel obstruction and physical examination

A 75 y/o man arrives in ED from a nursing. 
He complains abdominal pain. 
No fever, no jaundice, abdomen presents distended. 
Inspection shows a midline old scar,
there is diffuse rigidity, 
increased bowel sounds and vomit on the sheets. 

Can history and clinical examination contribute to diagnosis of bowel obstruction?



















Conclusion 

Medical history and physical examination are a good method in evaluation of a patient with a suspected bowel obstruction. Age > 50 years, distended abdomen, increased bowel sounds, vomit, history of costipation,  previous abdominal surgery  alone can increase the probability of bowel obstruction. The combination of three of this has a very high LR+ from 19 to infinity! Although in some case clinical examination could be diagnostic of bowel obstruction without any other investigation, the practice of plain radiography is still very diffused….what about it?


Bibliography 

H Bohner, Q Yang et al:
Simple data from history and physical examination help to exclude bowel obstruction and to avoid radiographic studies in patients with acute abdominal pain. 
Eur J Surg 1998; 164:777-784


Ciro Paolillo and Ilenia Spallino



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1/26/2012

Septic Arthritis and Arthrocentesis

A 33 y/o male comes to the ED for fever, knee swelling and pain.
He has a history of joint surgery because of trauma, and prothesis, dating 4 years before.
He is HIV positive
He presents feverish (38°C), the left knee is swollen and hot.
WBC 34.000/μL, CRP 109 mg/L, PCT 0,05 ng/mL.
As we have seen in previous post, history, clinical examination and serum test are not useful to rule out or in a septic arthritis. It’s time to perform arthrocentesis: sWBC: 60x109, sLactate: 10 mmol/L


Are this findings useful?










Conclusion 

Although arthrocentesis is not a risk-free procedure, synovial fluid analysis is essential for the diagnosis. 
sWBC count has been studied in several trials but a significant heterogeneity was noted so it should not be used in isolation to rule in or rule out the diagnosis of septic arthritis, anyway it should augment the entire clinical evaluation.
Synovial lactate, instead, has consistently demonstrated desirable diagnostic properties to rule in septic arthritis using a threshold of >10 mmol ⁄ L. 


Bibliography 

C. R. Carpenter et al;
Evidence-based Diagnostics: Adult Septic Arthritis
Acad Emerg Med Aug 2011, vol 18 n 8. 

see previous...


Ilenia Spallino

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1/18/2012

Septic Arthritis

A 33 y/o male comes to the ED for fever, knee swelling and pain.
He has a history of joint surgery because of trauma, and prothesis, dating 4 years before.
He is HIV positive
He presents feverish (38°C), the left knee is swollen and hot.
WBC 34.000/μL CRP 109 mg/L PCT 0,05 ng/mL



Are history, clinical examination, serum test enough to rule out or in a septic arthritis?

















Conclusion 

No finding from the history significantly decreases or increase the probability of septic arthritis (SA), included hystory of HIV infection; only recent joint surgery (<3 months ago) or a joint prosthesis with skin infection, significantly increases the risk of septic arthritis, but attention, the absence does not rule out SA!
Data about physical examination and hystory are inconcludent, the presence or absence of classical clinical signs (pain with motion, limited motion, tender swelling, joint effusion, increased heat redness, fever > 37.5°C, axial load pain) is not useful to rule in or rule out septic arthritis.
Serum test like WBC, ESR, CRP are not useful, instead Procalcitonin is generally specific with very poor sensitivity. 
…..So what?




Bibliography 

C. R. Carpenter et al;
Evidence-based Diagnostics: Adult Septic Arthritis
Acad Emerg Med Aug 2011, vol 18 n 8. 



Ilenia Spallino

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1/08/2012

Soft tissue abscess: clinical plus ultrasound evaluation

Male 65 y/o, he complains pain and swelling in left groin, he has history of hypertension. He has not fever. Clinical examination shows swelling, skin is hot and  eritematous.






Is it an abscess, a cellulitis or something else? 
















Conclusion 


To use ultrasound on eritematous and swelling skin is very helpful 
Abscesses presents as a spherical structure with “pus in movement”.  
Celluliti’s morphology, instead, has a “cooblestoning effect”, with diffuse hyperechogenicity of subcutaneous fat.

Ultrasonography is a useful adjunct to clinical evaluation of soft tissue infection, it increases diagnostic accuracy and guides treatment decision.


Bibliography 

BT Squire, JC Fox, C Anderson
ABSCESS: applied bedside sonography for convenient evaluation of superficial soft tissue infections
Acad Emerg Med July 2005, Vol. 12, No. 7 

DW Struk, PL Munk
Imaging of softs tissue infections
Radiol Clin of N Am vol 39 n2 Mar 2001




Ciro Paolillo


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