23 Jul - Pleural Effusion

This AMs case was a patient who presented with dyspnea and R chest pain 6 weeks following an episode of pneumonia.  CXR revealed a large R sided pleural effusion.

Thoracentesis was performed with findings of cloudy fluid with a protein ratio <0.5 but an LDH ration >0.6, consistent with an exudate.  No organisms were seen on gram stain and the glucose and cell counts were unremarkable.

Since we are not doing thoracentesis yet in the sim lab - you all should at least review the video here at the NEJM website before peforming this procedure.  Common ommisions that I have witnessed include not having the patient fully exhale and hold their breath when removing the catheter from the chest at the completion of the procedure.

To interpred the results of the pleural fluid analysis, consult these articles here and here by the guru of pleural fluid analysis Dr Light.  His criteria show up frequently on exams and challenge bowls:

pleural fluid / serum protein ratio >0.5
pleural fluid / serum LDH ratio >0.6
pleural fluid LDH > 2/3 the upper limit of serum normal value

Any one is sufficient to diagnose an exudative effusion, but the specificity is only 82 - 83%

Light's criteria are the most sensitive (98%), but a serum albumin - pleural albumin of <= 1.2 or a pleural fluid cholesterol >= 60 are both more specific at 92%

22 Jul - Pulmonary Embolism

This AMs case was a patient admitted with subacute onset of dyspnea.  Initial evaluation revealed an elevated D-dimer, swollen LLE and normal CXR.  CT PE study revealed extensive bilateral PEs with proximal involvemetn and R heart strain.  He had made several recent long car trips but had no other known predisposition to thromboembolism. 

For a recent summary of acute PE management see this NEJM review from this past week's issue.

Regarding selection of PE patients for outpatient treatment or early discharge - know that the data to support this practice is of poor quality and that patients with hypoxemia, RV dysfunction, large proximal PEs, and obesity (>110 kg) were excluded from the studies of outpatient treatment.  These individuals should be managed as inpatients until oral anticouagulants are at therapeutic levels and clinical stability is achieved.  This recent review should be noted before you consider early discharge of a PE patient.

21 July - Mechanical Complications of Acute MI

F/u from Dr Sullivan's CPC of a patient who presented with an acute MI and sustained a septal rupture developing an acute VSD.  Despite odds against it, this patient survived with emergent CT surgical intervention.

Mechanical complications of AMI (free wall rupture, septal rupture, papillary muscle rupture w/ acute MR, RVMI, and cardiogenic shoc) are all favorites of medicine test writers.  I will refer you to this recent Cleveland Clinic CME website for the latest and greatest - review this for boards / inservice!

Steroid therapy, which this patient had recieved, is an identified risk factor for myocardial rupture in some reports, but this link has been debated.

July 16 - Epilepsy

"For when the breath does not find entrance to him, he foams and sputters like a dying person. And the bowels are evacuated in consequence of the violent suffocation; and the suffocation is produced when the liver and stomach ascend to the diaphragm, and the mouth of the stomach is shut up; this takes place when the breath does not enter by the mouth, as it is wont. The patient kicks with his feet when the air is shut up in the lungs and cannot find an outlet, owing to the phlegm; and rushing by the blood upward and downward, it occasions convulsions and pain, and therefore he kicks with his feet."
-Hippocrates, "On the Sacred Disease" ca 400BCE

Late entry here. Pt was a pregnant female who presented with recent seizure activity and had recurrent seizures in the hospital.  She had been off anticonvulsant therapy for some time.  Seizures become more common in about 25% of pregnant women with epilepsy, and a variety of reasons may play a role:

1- increase clearance and larger VD for antiepileptic drugs (AEDs)
2 - noncompliance or cessation of AEDs due to concern for fetal risk
3 - possible lower sz threshold related to stress, sleep loss, and hormonal changes

Key poitns in managing epilepsy in women of childbearing age:

Ideally have effective seizure control before conception

Supplement folate

Use monotherapy at lowest effective dose

Avoid valproate if possible - this drug has the strongest link to teratogenicity.

The newer agents lamotrigine and carbamazepine may have an increase risk of cleft lip and palate.

This article from the Neurology journal reviews the current literature and concludes that no antiepileptic drug has been shown to be conclusively "safe" but registry data indicates that most agents can be used with a low incidence of fetal complications.

Jul 15 - DVT

Todays case was a 60 y/o patient with a 9 year history of hemipareisis from a prior hemorrhagic stroke.  He was admitted with acute onset RLE pain and swelling and found to have an acute DVT.  His D-dimer test was positive and a doppler US revealed a partially occlusive distal thrombus.

Review this Annals In The Clinic article about DVT management.  Also has some slidesets that can be used for student teaching.

Whe establishing your pretest probability to determine diagnostic testing - know that there are different Well's criteria for DVT and Well's criteria for PE.

Regarding testing for thrombophilia - there are no clinical trials to support this practice according to a recent Cochrane review of the topic.  This extensive review in the American Journal of Medicine contradicts the MKSAP answer from today, in that it proposes that there are very few indications for thrombophilia testing, and there is little evidence to back up the effectiveness of testing in these circumstances to prevent clinical events.

Jul 14 - Chest Pain

Don't tell my heart, my achy breaky heart
I just don't think it'd understand
Cause if you tell my heart, my achy breaky heart
It might blow up and kill this man...
-B. Cyrus






This mornings case was a patient admitted with substernal chest pain and pressure radiating to the left arm and jaw.  The symptoms developed shortly after hearing some traumatic news about a family member.  She had a known history of CAD with a prior MI, CABG, and later Stent to an occluded SVG.  Her initial ECG revealed antero-septal q waves and ST elevations (similar to old ECGs)

Her initial cardiac enzymes were negative, but the second set at 6 hours revealed a significantly elevated troponin of 22.  Urgent cardiac catheterization was peformed which revealed intact bypass grafts and no obstructive coronary disease.  LV-gram revealed apical ballooning sonsistent with Tako-tsubo cardiomyopathy.

Teaching points:
Review this article on the evaluation of acute chest pain.  All acute chest pain presentations must be rapidly screened for immediately life threatening diagnoses - MI, PE, dissection, and pneumothorax.  The differential diagnosis of chest pain is vast, but concentrate initial efforts at ruling in or out the four mentioned above.  Most ED chest pain protocols trigger immediate ECGs, chest X-rays, cardiac enzymes, and oxygen saturation measurements that can give you clues to PE, MI, and PTX.  Dissection is a little more tricky, and high clinical suspicion is key.

Takotsubo cardiomyopathy, also known as apical ballooning syndrome, stress induced cardiomyopathy, and broken heart syndrome, is reviewed in this NEJM Clinical Decision Making article from 2009 - their case has many features similar to the one discussed today.

The optimum evaluation and treatment of acute coronary syndromes is constantly in evolution, and this editorial summarizes the current optimum approach to patient management.  Key point - risk stratify patients using a valid tool such as the TIMI risk score, and reserve coronary angiography for those in the high risk category.

Finally - use caution in treating women with heart disease the same as men.  This study and review of prior trials suggests that using a routine invasive diagnostic strategy in women is of no benefit and may in fact be harmful.  This data is in clear contradiction to results demonstrated in men.

Jul 9 Encephalitis

Was not there for the presentation, but am very familiar with the patient discussed.  Middle aged gentleman with 3 - 4 weeks of altered mental status, headaches, and jerky limb movements.  MRI negative, but CSF persistently abnormal with elevated WBC (all lymphos), elevated RBC, and high protein.  Rec'd an initial diagnosis of aseptic meningitis but was readmitted when symptoms worsened.  This time he improved substantially with empiric acyclovir treatment for suspected HSV encephalitis.  Some key points:

There is only 1 type of encephalitis that is readily treatable, and that is HSV-1.  Be sure to test for it - and the test of choice is PCR of spinal fluid.  Do not order "HSV serology" because you will not get the answer the patient needs.  You can check for other things like West Nile Virus or the equine encephalitis viruses, but there is not much you can do for the patient.  So if you only have a couple drops of CSF - do the HSV PCR.

There is a reseource to be aware of: the Tennessee Unexplained Encephalitis Survey (TUES) study: They will enroll your patient in an ongoing study that will test any leftover CSF and blood samples for an extensive panel of encephalitis agents. 

The IDSA has published a comprehensive practice guideline that briefly reviews the exposure risks, testing, and treatment for pretty much any cause of encephalitis.

Jul 8 - MMP

MMP in todays's case coud mean multiple medical problems or multiple myeloma patient.  This case demonstrated how to take a rational approach to evaluating a complex patient with multiple simultaneous diseases presenting with a varied symptoms.  It shows that Occam's Razor is sometimes dull.  Never forget Saint's triad, or the famous Hickam's dictum - "A patient can have as many diagnoses as he damn well pleases!"

Some of this patients several diagnoses:

Obstructive Sleep Apnea:  given the growing waistlines of a growing population this is a growing problem.  OSA patients can have the same impairment driving as an intoxicated patient.  Treatment with CPAP improves quality of life and decreases car accidents.  Effect on other outcomes is not as well defined.  It is criticial to differentiate OSA from Central Sleep Apnea as CPAP might not be of much benefit in the latter.  One form of this is a rare genetic disease called Ondine's curse where patietns simply lack the respiratory drive when asleep.  So don't ever cheat on water nymphs.

Multiple myeloma was an almost indicental diagnosis in this patient.  Classic findings of bone pain and hypercalcemia were absent in this case, and the renal failure seemed to be largely due to obstruction in this case.  Nevertheless, SPEP and UPEP revealed a monoclonal spike and the bone marrow biopsuy revealed elevated plasma cells.  Skeletal survey had a few small lytic lesions in the femur and humerus.

Cardiac Exam Skills - Online Resources

Below are some links to cardiac auscultation aides.  All have free content, some direct you to optional purchases.  I am thinking of getting some of the blaufuss tools for the sim lab - post comments if you find their free stuff useful.  Looks like they have a device to pipe the audio from the murmurs into your own stethoscope. 

Mulimedia cardiac auscultation tools - matches sounds with videos of physiologic process to enhance learning:
http://www.blaufuss.org/

Large database of free heart sounds from Texas Heart Institute.  Free is good!
http://www.texasheartinstitute.org/education/cme/explore/events/eventdetail_5469.cfm

Murmur learning tool - 5 free murmurs, the rest cost ~$150:
http://www.cardiosource.org/Certified-Education/eLearning-and-Products/Heart-Songs-3.aspx

7 July - Evaluation of Syncope

The first MR of the academic year focused on a 78 year old patient with a history of syncope.  He had two prior episodes over the preceeding three years.  The most recent event had a few second prodrome followed by loss of consciousness and a fall to the floor.  He had a history of DM and treated hypertension, but blood glucose and blood pressure checked by family were normal.  ECHO and ECG were normal.  Postural blood pressure measurements were normal.  The most likely diagnosis in this case was neurocardiogenic syncope.

The evaluation of syncope usually results in unnecessary testing that rarely leads to a diagnosis.  The frequent use of carotid ultrasound is unsupported by evidence and rarely if ever alters patient management.  Even routine lab testing, including cardiac enzymes, are almost always a wast of money unless there are clinical symptoms other than syncope to suggest their use.  This Archives of Internal Medicine article summarizes the diagnostic yield of most commonly used tests.  The highest yield test was also the cheapest - postural blood pressure management.  This 2000 NEJM review directed at primary care physicians walks you through the preferred, rational evaluation of this condition.

The evaluation of neurocardiogenic syncope is summarized in this 2005 NEJM article.  Tilt table testing remains the gold standard for evaluation of this condition.  Treatment has traditionally been with beta blockers, however there is little evidence to show they work.  Midodrine, fludrocortisone, and SSRIs have all been shown to be effective.

Remember - syncope is a finding, not a diagnosis, but in most cases you need little more than your brain, ears, and hands to make the diagnosis.