Showing posts with label Teaching. Show all posts
Showing posts with label Teaching. Show all posts

Friday, July 18, 2008

Day #18 - Cirrhosis

Today's case was of a 52 year-old man who presented with new diagnoses of cirrhosis with ascites, portal hypertension and probable variceal bleed who also had a new diagnosis of diabetes mellitus. The discussant showed us, although in his own uniquely tangential way, the type of clinical reasoning that great physicians use in arriving at a diagnosis.

There are a number of valuable teaching points today:

1) Ascites:

Etiology
  • Elevated Hydrostatic Pressure --> CHF, constrictive pericarditis, Budd-Chiari, cirrhosis, IVC occlusion
  • Decreased oncotic pressure --> malnutrition, nephrotic syndrome, protein losing enteropathy, cirrhosis/liver failure
  • Increased fluid production in peritoneum --> infection (TB), neoplasm
Diagnosis on History/Exam
History
  • Increased abdominal girth and ankle swelling are the most sensitive (greater than 85%)
  • Past history of hepatitis or cancer are the most specific (greater than 85%)
Exam


  • Not likely if no bulging flanks, no flank dullness and no shifting dullness
  • Likely if fluid wave, shifting dullness, and peripheral edema (LR+3.8/-0.2)
2) Special Tests:

The team today also mentioned that they had performed a paracentesis in order to evaluate the ascites. This is important as paracentesis can:
  1. Provide diagnostic clues
  2. Exclude SBP
The Serum Albumin-Ascites Gradient (SAAG) is a valuable tool in deciding if the ascites is due to portal hypertension. SAAG = Serum albumin - Ascites Albumin. If <11 style="font-style: italic;">It should also be prevented in cirrhotic patients post GI bleed using TMP/SMX 1DS PO BID x 7d or CIPROFLOXACIN 500mg PO BID x 7d

The diagnosis can be made on the paracentesis:
  • PMN >250 (LR + 6 LR - 0.2)
  • WBC >1000 (LR + 9)
  • Inoculation of blood culture bottles (fill them with required volume) can improve yield of the C/S
NB: In most cases, you do not need to use FFP/Platelets pre paracentesis.

Initial treatment is with CEFTRIAXONE 2g IV q24h with coverage narrowed to the culture data. You need only treat for 5 days.

Patients should get 1.5g/kg of 25% albumin within 6h then 1g/kg on day 3.

NB: Think of missed perforation if multiple organisms grow in the culture or if the WBC count in the fluid is much greater than 1000.

Friday, July 4, 2008

Day #4 - Acute Monoarthritis

Today the discussant spoke about the approach to acute monoarthritis. It was a very articulate presentation and your participation was excellent.

To clarify the point on treatment:

  • CEFTRIAXONE 2g IV q24h will cover most organisms including GC, most streptococci, Staph. aureus and many gram negatives. It is not the ideal agent for Staph. aureus, so if it turns out to be methicillin *sensitive* staph. aureus you should change to ANCEF (1g IV q8) or CLOXAILLIN (2g IV q6)
  • Is MRSA a possibility or is this a prosthetic joint? --> ADD VANCOMYCIN (renal dose)
  • Is there reason to worry about pseudomonas? --> I would suggest VANCO+CEFTAZADIME and ID consult.
  • Prosthetic Joint = Call ortho. Probably should not be admitted to medicine if septic prosthetic joint is the main reason they are in hospital -- they need to go to the OR for wash-out and, in my experience, this is much less likely if they are admitted to GIM instead of orthopedics. Should get ID consult as well.
This article from JAMA is an excellent reference on making an evidence based diagnosis of septic arthritis on history, physical and laboratory examination.

VIDEO: How to do an arthrocentesis of the knee

Highlights include:

Risk Factors: Age, DM, rheumatoid arthritis, joint surgery, hip/knee prosthesis, HIV infection, skin infection, (unprotected sexual intercourse for GC)


History: Pain and swelling are present >80% of the time; fever is present only 60% rigors and chills less than that.

Synovial Fluid Exam (LR less than 0.1 rules out; LR >10 rules it in)

  • WBC <=25,000 unlikely septic arthritis (LR 0.32) unless immunosuppressed
  • WBC >=25,000 LR 2.9
  • WBC >=50,000 LR 7.7
  • WBC >100,000 LR 28
  • PMNs <90%>
  • PMNs >90% LR 3.4
Important to note that measurement of glucose, protein, lactate do not appear to be helpful according to the literature. Also note that LDH in the joint may have some utility in ruling out as LDH <250>