Evaluation of Hypoglycemia

Interpretation of labs drawn during the work up of hypoglycemia (72 hour fast or mixed meal test). 

From the Endocrine Society’s Clinical Guidelines on Evaluation and Mangement of Adult Hypoglycemic Disorders (pdf)

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!

Dx of Meningitis - CT before LP

25M college student p/w worst headache of his life, fevers, chills, painful & stiff neck. PMH epilepsy. Off meds. Hasn't had a seizure in 10 years. No other significant past medical. Tachy, febrile, tachypnic, normal O2 sat. Positive nuchal rigidity on exam. Oriented, follows commands, no motor or gaze palsy. WBCs 14. Does he need a head CT before LP?

Click here for a JAMA Rational Clinical Exam piece on bedside dx of acute meningitis (can you trust Kernig and Brudzinski?), the study that established the CT before LP rules, and some useful cards from ALiEM's PV series to enhance your bedside recall of these rules.

tPA for the Management of Acute Ischemic Stroke - FreeOAM vs. {industry funded} Guidelines

In noon conference today, the presenting resident reviewed the AHA/ASA March 2013 guidelines on management of acute ischemic stroke. It was a good overview of the guidelines, but there wasn't a lot of room for debate on the evidence for and against tPA in this scenario. Luckily I've been privy to the tPA in acute stroke debate in the #FOAMed community.

Mini FOAMed Lit Review on the use of tPA for the management of acute ischemic stroke:

1. Emergency Med Lit of Note were out of the gate quick early this year to question the integrity of the ACEP guidelines on this topic.
2. theNNT convinced me with their thorough evidence based review. Their "red light" made it clear to me what the answer is on this topic. 
3. Recently LiTFL posted a two part series on this topic by Michelle Johnston. She left the final decision on the validity of tPA use for this indication to the reader, but her analysis is thorough and presents a strong case to exercise caution when considering tPA. 
4. Just this morning ALiEM's Todd Seigel posted a review focused primarily on the NINDS study, AHA, & ACEP guidelines. His post stands in contrast to the other FOAM contributions to this debate, and Graham Walker of theNNT & MDCalc was quick to point out this contrast. 

But can FOAMed stand up to 3 major organizations (AHA, ASA & ACEP) all arguing strongly for use of tPA in select patient groups?

Thankfully, there's at least one organization that has stood strong & reasonable. The AAEM have put out statements, commentaries, educational material, & letters all asking for an injection of evidence-based, calmly considered, carefully weighed thought, skepticism, debate, and further investigation on this topic. 

Despite some guidelines, it can at least be said, tPA for the management of acute ischemic stroke is not the standard of care.

Bad Belly

57 year old male with a long history of heavy alcohol consumption presents with complaints of severe abdominal pain and nausea. On exam he's mildly agitated and disoriented to time. Mildly febrile, tachycardic, tachypnic, blood pressure 90s/50s, normal O2 saturation. Jaundiced, numerous spider angiomata including telangiectasias on his face, arms, and chest. Abdomen is grossly distended, obvious fluid wave, and diffusely tender, no guarding but tenderness is elicited on abdominal percussion and rebound.

What acute illness to you most suspect? How will you confirm the diagnosis? How will you perform the diagnostic test? What results do you suspect? If results confirm your suspicion, how will you manage the patient?

Click here for checklists, videos, and guides on this diagnostic question.

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.

How do you remember the MEN syndromes?

Have a good mnemonic for remembering the MEN syndromes? If so, post it in the comments.

Check out this link for a great mnemonic for this!

Headache & Weakness

Case (What's the diagnosis, how do you know, and what is your management strategy?):

A 25-year-old female presented to the emergency department complaining of flashing lights in her right eye that started one hour earlier while watching a home movie. The patient reported that while trying to read, she was unable to discern the words but could understand words spoken to her. She also felt disoriented and thought that she was slurring her words. Following the onset of numbness in her lips, she noted weakness in her right leg. A bilateral parietal headache occurred shortly after the symptoms began. She denied any history of headaches and had no other medical problems. She was not pregnant and was not taking any medications. She denied use of illicit drugs or alcohol. Her family medical history was negative for migraine headaches. She was afebrile, with blood pressure 152/76, heart rate 96, respiratory rate 24, and oxygen saturation 100%. On physical examination, she had ptosis of her right eye and decreased sensation around the right side of her mouth. A right homonymous hemianopsia was present. Her right lower extremity muscle strength was 4/5 compared to 5/5 on left lower extremity. She ambulated well but had difficulty turning around to return to bed, stating she felt disoriented. Her headache was persistent during the examination but she had no photophobia. Complete blood count and electrolytes were within normal limits. Her urine drug screen was negative. There were no acute findings on head CT without contrast. Within 2 hours, her symptoms and headache completely resolved. In a young female with no prior medical history, what could this be?


Click here for the source of this case, the answers to the case, and a good review on management of this illness.

Alkaline Phosphatase: Sources

What are the sources of Alkaline Phosphatase?
What's a good Mnemonic to remember this differential Diagnosis? See link for answers.

Post in comments other mnemonics, memory tools, or trivia on this topic.

Young Man with Chest Pain - Stumper!

Watch this video for a Chest Pain Stumper! by The Consult Guys, a new series by Annals of Internal Medicine (ACP).

Click here for an important mnemonic to help you remember this mystery diagnosis! (also attached to this are the slides associated with the video linked above).

Metabolic Acidosis part I

Metabolic Acidosis (limited mostly to increased AG metabolic acidosis and delta-delta

Check anion gap
If anion gap increased --> suggests increased unmeasured anions: organic acids, phosphates, sulfates
If anion gap decreased --> suggests decreased albumin or increased unmeasured cations: Ca, Mg, K, Li, bromine, immunoglobulins

If increased AG, determine the delta-delta (or delta ratio) to assess for other concomitant metabolic abnormalities.

Delta-delta = (delta anion gap)/(delta HCO3)
Delta anion gap = Calculated anion gap - Expected anion gap
Calculated anion gap = Na - (Cl - HCO3)
Expected anion gap = Albumin x 2.5
Delta HCO3 = 24 - HCO3

If delta-delta value:
1-2 --> pure AG metabolic acidosis
<1 --> AG metabolic acidosis and concomitant non-gap metabolic acidosis
>2 --> AG metabolic acidosis and concomitant metabolic alkalosis

Aids for intuition:
If delta ratio > 2, this points to a relatively small delta HCO3 (as the denominator will be relatively small).
If delta ratio < 1, this points to a relatively large delta HCO3 (relative to delta AG).  Increased Cl can account for this.


Osmolal Gap = Measured osmolality - calculated osmolality
Calculated osmolality = (Na x 2) + (glucose/18) + (BUN/2.8)
If osmolal gap > 10, suggests ingestion

The New Building Blocks of Learning

Need to imbed the video, talking points, questions?

http://www.ted.com/talks/sugata_mitra_the_child_driven_education.html

1. Broadband

2. Collaboration

3. Encouragement

4. Challenge

Ptosis, Erythema, and Vision Loss - Case

Check out this cool ophtho case in JAMA 2013. I think the answer to the What would you do next? segment is the most important learning point.

Then, do these questions and review the answers. (Not posted here so as to not spoil the case).

Troponin Elevation DDx

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1860726/

Excellence in Medicine through Rescue from Failure- Gawande

Below you will find excerpts from a commencement address given by Gawande re: excellence in medicine, from a perspective I had never heard before. 

"... the best surgeons I saw involved the ability to handle complexity and uncertainty. They had developed judgment, mastery of teamwork, and willingness to accept responsibility for the consequences of their choices.  

...I thought that the best places simply did a better job at controlling and minimizing risks—that they did a better job of preventing things from going wrong. But, to my surprise, they didn’t. Their complication rates after surgery were almost the same as others. Instead, what they proved to be really great at was rescuing people when they had a complication, preventing failures from becoming a catastrophe. 

....When things go wrong, there seem to be three main pitfalls to avoid, three ways to fail to rescue. You could choose a wrong plan, an inadequate plan, or no plan at all.  

...But recognizing that your expectations are proving wrong—accepting that you need a new plan—is commonly the hardest thing to do. We have this problem called confidence. To take a risk, you must have confidence in yourself. In surgery, you learn early how essential that is. You are imperfect. Your knowledge is never complete. The science is never certain. Your skills are never infallible. Yet you must act. You cannot let yourself become paralyzed by fear.  

Yet you cannot blind yourself to failure, either. Indeed, you must prepare for it. For, strangely enough, only then is success possible.  

...[The attending surgeon had] never seen a serious belly problem [after carotid artery surgery]. But the surgeon was humble enough to understand that he could.  

...So you will take risks, and you will have failures. But it’s what happens afterward that is defining. A failure often does not have to be a failure at all. However, you have to be ready for it—will you admit when things go wrong? Will you take steps to set them right?—because the difference between triumph and defeat, you’ll find, isn’t about willingness to take risks. It’s about mastery of rescue."

Choose a high risk clinical scenario and describe No plan, Inadequate plan, and Wrong plan scenarios. Then describe the Right plan. Try this exercise regularly and your patients and your hospital will benefit greatly from your preparedness. 

This connects to point #9 from our post on Clinical Reasoning - Progressive Problem Solving. Review that post to reinforce principles in Clinical Excellence. 

put in an example high risk case and connect to EN

Sinus Transillumination

A simple and practical physical exam maneuver to aid in the detection of sinusitis and other sinus space-occupying lesions.

Review these notes from the FPnotebook and these videos on frontal (one and two) and maxillary (one and two) sinus transillumination and practice on a number of "normals", include in your routine examination, and of course use in your focused ENT exams.

Include the sinusitis scoring criteria (Sapira's).

AAA Screening

Read this adapted from from UpToDate 2010 then answer the following questions from the AFP 2005:

M.G., a 70-year-old black man, requests refills for his medicines. His medications include lisinopril, atorvastatin, glipizide, and daily aspirin. He smoked heavily when he was younger but quit about 15 years ago. He also asks that you order “whatever tests should be done at my age.”

1. You review MG’s chart and find he is up to date on most age-appropriate immunizations and screening. You consider screening him for abdominal aortic aneurysm (AAA). Which of the following screening regimens reflects the U.S. Preventive Services Task Force (USPSTF) recommendations on screening for AAA?
A. Screen men and women aged 65 to 75 years.
B. Screen men yearly between the ages of 65 and 75 years.
C. Do not screen men who quit smoking more than 10 years ago.
D. Screen men aged 65 to 75 years who have ever smoked.
E. Screen women aged 75 to 85 years who have ever smoked.

2. Which one of the following statements about AAA is correct?
A. Blacks and patients with diabetes are at increased risk for AAA.
B. There is a low risk for surgical complications from AAA repair.
C. Operative mortality for open surgical repair of an AAA is less than 1 percent.
D. Men generally die from AAA rupture at an older age than women.
E. An age of 65 or older, male sex, and a history of smoking are the major risk factors for AAA.

3. After you discuss the risks and benefits of AAA screening with MG, he decides to proceed with screening. Which of the following statements about screening for AAA is/are are correct?
A. Ultrasonography is the screening test of choice.
B. An estimated 500 men aged 65 to 74 years who have ever smoked would need to be screened to prevent one AAA-related death over five years.
C. Screening and surgical repair of large AAAs in older men decreases all-cause mortality.
D. Abdominal palpation is an adequate screening alternative.

Answers

Gout Review

This one-pager on gout was adapted from this In The Clinic review from Annals 2010. Review the article and answer the MKSAP questions at the end.

Answers

Surgical Site Infections Prophylaxis

After reviewing this 2011 review article from the AFP, you should be able to answer the following questions:

1. What are the six Surgical Care Improvement Project (SCIP) performance measures?

2. In the recent study referenced in the article, approximately what percentage of surgical patients received prophylactic antibiotics within the appropriate time frame?

3. When should repeat antibiotic administration be done?

4. What is the go-to prophylactic antibiotic for most clean-contaminated surgeries?

5. When should vancomycin be used prophylactically?

6. When should metronidazole be added to the prophylactic regimen?

Answers

Derm Terms

See the powerpoint for a review of dermatology terminology and analysis of a case of a HIV+ patient with fever and a generalized rash.

See the following resources for derm education and cases to practice:

Derm Atlas (atlas, cases, & quizzes)
Dermatology Glossary (terms with images)
AAD Med Student Core Curriculum (modules)

Excellence in Clinical Reasoning

Adapted from Dhaliwal's 2011 article in JAMA & his 2012 article in Academic Medicine

1. Build rapport with your patient. For example, delve into the social history before getting into the clinical questions. E.g. occupation, family, home life, immigration history, travel history, etc. Have a positive demeanor. All this makes eliciting a complete history and performing a thorough physical exam much easier. Further, these social details might be the key to the diagnosis!

2. Allow the differential to guide investigations from the start. Develop a broad differential from the chief complaint and narrow the possibilities by asking pertinent questions and performing physical exam maneuvers that address these entities. This makes history taking and physical exam a more of an intellectual challenge, instead of just rote checklists. (Not to undermine checklists. Checklists support safety and quality. Checklists should serve as a back-up of "things not to forget" rather than the principle method of evaluating a case.)

3. Base of knowledge and experience guides evaluation. Without a large base of knowledge and experience, one cannot generate the "pertinents" of a case. Emphasize the importance of study of cases and clinical opportunities. This allows the clinician to develop "illness scripts" - pattern recognition of clinical entities - and the knowledge that allows accurate clinical reasoning when the presentation does not promptly lead to a clear diagnosis. You need to know the disease to detect the disease.

4. Problem representation. AKA the one-liner or the "Assessment". Synthesis of the pertinent details into a meaningful representation of the case that allows the clinician to connect the case to their database of illness scripts and clinical encounters, or appropriately reference their knowledge base to evaluate other possibilities.

5. Utilizing both pattern recognition and analytical reasoning. Familiarity with many different clinical presentations, illness scripts, frequently allows the clinician to steer their investigations to quickly confirm the most likely culprits, but when complex or unclear situations arise, the expert can use analytical reasoning supported by a broad knowledge of the field to guide the investigation.

6. Prioritize. A knowledgable and experienced clinician should be able to use the relevant details of the case to prioritize what conditions are most likely and what cannot-miss diagnoses must be considered.

7. Second opinion. Especially for complex cases, discuss the case and the clinical reasoning with others. One may find there are other ways to categorize the possibilities, other diagnostic algorithms  or new evidence that should be integrated into the work up.

8. Feedback. Follow up the case to its definitive conclusion. This follow up will provide feedback that allows the clinician to refine their clinical reasoning processes and build up their knowledge and experience base to help them in future encounters. Follow up outcomes, treatment responses, lab results, pathology, encounters with other providers, etc. This feedback will hone your judgement.

9. Progressive Problem Solving. Learn from every case, even the "easy" ones. Find a way to reformulate the case in such a way that you consider related challenges, such as potential complications, rare diagnoses, common mistakes, contingency planning, medication side-effects, treatment failures, etc.

10. Simulate. Advance your cognitive skills through case simulation. Review published cases, case-quizzes, and interactive/virtual cases.

11. Deliberate Practice. Select specific competencies that need improvement. Focus on the skill, seek out guidance, study the relevant literature, and repeatedly practice until habitual mastery is achieved.

12. Defend against Cognitive Errors. Of course you cannot defend against cognitive error if you are not aware of the types of cognitive errors that clinicians are susceptible to. This is a whole other topic that will be discussed in the future.

13. Model these behaviors for the benefit of other learners & yourself.

Expect to see more cases, differential building, illness scripts, analytical reasoning, and cognitive errors discussed on this blog.

Cirrhosis Treatment Nuggets

Nuggets taken from AFP review paper on treatment in cirrhosis/chronic liver failure

Link to paper:  Liver Failure Treatment

1) In a patient with ascites, list the Grade A treatment recs.  (hint: 3 types)

2) What percentage of patients with ascites have cirrhosis as its etiology?

3) List causes of ascites that have SAAG <1.1 (hint: 1 malignant, 1 infectious, 1 endocrine/exocrine)

4) If propranolol is contraindicated for variceal bleeding prophylaxis, what's the next drug you can use?

Child-Pugh criteria mnemonic

HAPI BAbi

-hepatic encephalopathy
-ascites
-PT/INR

-Bili
-Albumin

Diagnostic Criteria for SLE

In keeping with our series on mnemonics for rheumatology diagnositic criteria: One on Lupus-

Article from AFP 2003 on Dx of SLE

How many criteria are there?
How many do you need?
What are the criteria?
Know a good mnemonic to remember?

Answers

Hair Loss

A frequently overlooked topic in general outpatient medicine, but should always be thoroughly evaluated and treated since it can be psychologically quite damaging to the patient and may be an indicator of underlying systemic disease.

A good article from the AFP, 2009 on the differential and treatments.

Name the diagnosis given the description and give a brief pathophysiological description of the diagnosis:

1. Focal, non-scarring, well-demarcated, normal scalp. Tip-off - exclamation point hairs.

2. Diffuse hair thinning in an elderly woman. Frontal hairline intact.

3. Focal hair loss with scaling scalp

4. Psych patient with patchy hair loss

5. Large amount of diffuse hair loss. 3 months ago the patient was in the ICU for a severe pneumonia.

Answers