Friday, August 20, 2010

Aug 20 - vertebral osteomyelitis and epidural abscess

This mornings case was a 51 year old man presenting with one month of progressive back pain (thoracic) associated with low grade fevers, leukocytosis, and weight loss.  Imaging via CT at an outside facility revealed degenerative changes, spinal stenosis, and not much else.  He presented here febrile with some lower extremity spasticity but no bowel or bladder dysfunction.  he did have decreased sensation in the lower legs.  There was point tenderness over the mid thoracic spine.

There are multiple red-flag symptoms in this back pain presentation.  This recent evidence based guideline from Annals identifies some common alert signs and presents an algorithm for workup:

In this case the patient was found to have vertebral osteomyelitis an epidural abscess due to methicillin susceptible Staphylococcus aureus and was taken for surgical decompression.  He is in the early stages of an 8 week course of IV antibiotics. 

Some key points:

Medical therapy with IV antibiotics alone is appropriate therapy for select patients with epidural abscess according to this Arch Int Med study.  This is a bit of a change from previous dogma.

There are no practice guidelies dictating duration of therapy, with differing opinions regarding duration of therapy.  I generally choose 8 weeks, but this NEJM review from March 2010 suggests a duration of 6 weeks for most patients.

Regarding the efficacy of vancomycin compared to nafcillin for MSSA - see these articles:

AAC Jan 2008 - mortality with vanco 37% compared with 18% treated with beta-lactams.
Medicine Sep 2003 - study of MSSA bacteremia without endocarditis - failure rate with vanco near 20% compared with no failures in the nafcillin group.

The bottom line is beta lactams are clearly superior to vancomycin in S aureus infections, and in the case of serious or life threatening S aureus infections I feel it is worthwhile to desensitize to beta lactams in order to use these agents if at all possible.

Aug 19 Syncope and Pulmonary Hypertension

This case was an elderly female with previously repaired aortic stenosis (mechanical AVR 15 years prior) who presented with recurrent syncope over the past 1 - 2 years.  The syncope occured with exertion and was increasing in frequency.  She carried a diagnosis of hypoxemic "COPD" but no PFT records were available.  PaO2 was low, and there was no evidence of CO2 retention.  She was suspected of having pulmonary hypertension by ECHO but had refused R heart catheterization to confirm. 

Will not go into discussion of syncope workup here - see this post from July 7.

Effort syncope has been described as a common symptom in primary pulmonary hypertension for quite some time.  An early effiort to identify the mechanism found progressive decreases in blood pressure ultimately resulting in acute R heart failure accounted for the syncopal attacks.  Tachy or brady arrhtyhmias occured but did not seem to be responsible for the acute drop in BP.

A nice review of primary pulmonary hypertension from AAFP is here.

Thursday, August 19, 2010

Aug 18 - Lupus Flare

Today's case was a patient with a known prior history of SLE that presented with multiple complications - including fevers, arthralgias and myalgias, and a rash on her face and abdomen.  Workup revealed evidence of multisystem disease, with elevated cardiac enzymes, hematuria, anemia, and thrombocytopenia.  Complicating her picture was a recent hospital stay where she rec'd heparin, and anti-heparin antibodies were positive. 

Peripheral blood smear revealed schistocytes:


Click this link for a nice review of mircoangiopathyc hemolytic anemia from the American Society of Hematology Image Bank

The working differential was HIT/HAT vs TTP vs other thrombotic microangiopathy.  TTP incidence is elevated in patients with SLE, and autoantibodies to ADAMTS-13 seem to play a role in pathogenesis.

Here is a link to another review of SLE pathogenesis in general from a recent NEJM article.

Monday, August 16, 2010

11 August - cholangitis

Running behind on blog updates due to a recent plague visitation at the Rasnake house. 

Two cases recently presented of patients with biliary tract complications.  One was a patient with fever, jaundice, and leukocytosis with a history of previously instrumented biliary tract due to carcinoma - diagnosis was cholangitis. 

Charcot's triad: rever, RUQ pain, and jaundice
Reynold's pentad: above three plus mental status change and hypotension.

Broad spectrum antibiotics to cover gram negative rods and anaerobes are important, but the key to management is decompression of the biliary tree via ERCP or other invasive methods.

The other case was a patient with a progressive mass in the vicinity of the pancreas but separate from pancreatic tissue that had been slowly enlarging over many months.  Most likely diagnosis in this case is lymphoma pending tissue biopsy.

Friday I was out due to monthly residency review meeting - regular updates will resume this week.