Dx of CHF in Dyspneic Pt: Need Echo?

53M PMH unknown 30 pack-year smoker presents with dyspnea to the ED. It's 2AM Saturday morning. The ED is PACKED with traumas, boarders, psychos… not to mention med students, residents & nurses strung out on caffeine or their stimulant of choice. Pt is desat'ing. Need to decide quick: Diuresis vs. Nebs? Diuresis won't help a dried out COPDer, and adrenergic nebs won't help a drowning CHFer. Echo Tech unavailable (this county hospital makes strategic budget cuts). 

How do you proceed?

NB: The H&P is very useful! Take the time to interview & examine the patient. Tell the med students & nurses to QUIET DOWN so you can hear that S3!

PV CHF LRs Collection:
Rivas CHF Dx Stats Collection:

NB2: Keep in mind that in CHF most findings are not conditionally independent  so usually cannot combine LRs for post-multiple-tests probabilities. Instead, rely on the most powerful finding you discover in that case (e.g. S3 to confirm dx or BNP less than 100 to exclude dx of CHF in dyspneic pt). Awesome free online course on Medical Decision Making btw. 

ROC Curves [BNP outperforms Echo EF%]



NB3: Here's the that shiny pearl you were waiting for…

CHF Dx Algorithm

NB4: This algorithm makes it look like H&P is useless. It's EXTREMELY useful (see LR tables above)! If you still can't make the diagnosis, obtain ECG & CXR. It should be the rare case when H&P+EKG+CXR is insufficient to make the diagnosis. In those scenarios, order BNP. Then, if BNP is indeterminate, perform bedside echo for Doppler MV Analysis for low Early/late (E/A) velocity ratio or short MV flow velocity Deceleration Time (DT) to cinch the diagnosis. Refer back to Rivas CHF Dx Stats. 

Explanation of MV E/A Ratio from Echo Doppler:

How to perform bedside Echo doppler MV assessment?
- Liz Turner from UC Irvine on FATE Exam: http://www.youtube.com/watch?v=9ybQ10m3uEY
- - That didn't quite answer my question, but came close. #FOAMed US gurus out there, help us out! Teach US!

Sources:
See losrivas EN Note. 

Ultrasound before MCTPA for PE dx

57M PMH COPD on home O2, smoker, CHF (baseline EF 30%), HTN, DM, obese (BMI 35), CKD (baseline Cr 1.6) presents to the ED with acute onset sharp, pleuritic chest pain at the right anterior chest radiating to the right axilla. Sinus tach on EKG with LVH & TWI that were present on prior EKGs. Tachypnea, O2 sat 90% on 4L NC. Afebrile. BP 127/89. A rhonchi & rales bilaterally. 3/6 holosystolic murmur throughout precordium. Obese abdomen. Bilateral LE edema pitting to the knees. Cr 2.2. WBC 12. CXR poor inspiration, bibasilar interstitial congestion, cardiomegaly, no pneumothorax, no fractures. It's a saturday night (skeleton crew - U/S tech isn't in, radiologist is tele-radiology, only one CT-tech in house with multiple emergent CTs in que). Pt has had multiple chest CTs in the past.

What's the risk of PE? Do you order a D-dimer? If you have a moderate to high suspicion for PE, do you go straight to CTPE? What about the likely delay in CT & the pt's acute on chronic renal failure? Another CT - are you worried about radiation exposure? Is there a way to spare this pt the CT?

A new study provides insight on a new diagnostic algorithm to to reduce the burden of CT for PE in the ED - if you've got the docs with the right skills! And again ALiEM provides PV Cards for easy access to relevant diagnostic & treatment rules and MDCalc helps too!

Alkaline Phosphatase and Shortness of Breath

A twenty year-old black female presents to the emergency department complaining of gradually worsening shortness of breath, very gradually worsening over 3 months. She tried her friend's inhaler but it provided no relief. Her only other complaint elicited on review of systems is a new bothersome rash on her shins.

On exam she is a slender woman. Vitals are normal. She has trace wheezes in the mid to upper lung fields bilaterally. Her breaths are somewhat shallow even when asked to "take a deep breath". She has about a dozen slightly raised, tender, mildly erythematous round lesions approximately 1cm in diameter on her pre-tibial legs bilaterally.

Labs are notable for an alkaline phosphatase of 156. Her calcium was elevated at 10.8. Other labs were unremarkable.

What diagnosis do you suspect? What is the next test you would order? What are the results you expect?

Click here to find out.

Tuberculosis

Comprehensive review article on tuberculosis from NEJM by Zumla et al, 2013.

Related: An article from Journal of ID, Metcalfe, et al. 2011, re: the use of inteferon-gamma release assays in diagnosis of active pulmonary TB.

CME Questions for this article from the NEJM website:

1. Risk of developing active TB among pt's with latent infection?
2. Which is true re: diagnosis of latent or active TB?
1. TB skin test is as specific as interferon-gamma release assay but less sensitive in diagnosing latent TB. 
2. solid culture medium is the standard for diagnosis of active TB. 
3. interferon gamma release assays are useful in the diagnosis of active TB. 
4. the Xpert MTB/RIF assay test is more sensitive than smear microscopy. 
3. Which is true re: HIV & TB coinfection?
1. Early ART therapy has no effect on mortality. 
2. Early ART therapy improves outcomes in pts with TB meningitis. 
3. IRIS occurs in at least 10% of HIV-infected patients who start ART during TB treatment. 
4. The most common manifestation of IRIS is a maculopapular rash.