Wednesday, April 30, 2008

Wednesday April 30, 2008
Board style question for Critical Care fellows.


Case: 42 yr old male admitted with Guillain-BarrĂ© Syndrome and intubated due to rapidly falling vital capacity. Patient otherwise remain fairly stable and sedated with average dose of 5 mg/kg/hr Propofol. Unfortunately, patient failed 5 days of Plasma exchange therapy. On day 6, pt develop exacerbation of his baseline asthma and was started on IV solumedrol but steroids were discontinued next day on neurology’s recommendation as it may prolong recovery from GBS. All labs and clinical exam otherwise remain stable including mental status which was assessed briefly each morning while off sedation. DVT and GI prophylaxis on place. Enteral feeding started on day 2. Bedside percutaneous trach and PEG has been planned.

While doing 'shift' on night of day 7, you noticed some downward BP "trend" but as labs and exam so far remain rock stable, you attributed it to sedation. While browsing 5 AM labs you noticed PH of 7.25 and bicarb of 14. Chem-7 showed Cr of 2.1 (baseline 1.1) and K of 5.7. As you get more attentive to patient, you noticed frequent episodes of bradycardia on monitor. Tracking back monitor in last few hours showed multiple alarms for bradycardia but was 'silenced' as this was the most stable patient in unit. Also pulse ox trend from upper 90s to lower 90s. You ordered lactate level, cardiac enzymes, EKG, CXR, broad spectrum antibiotics, panculture, adjust ventilator and gave IVF bolus. Lactate level is back with 7.2 and indeed patient has NSTE MI with Troponin-I of 7.1. CPK is reported in 5 K range. You called primary. Cardiology, Nephrology and ID services were put on consult. Pt. required another 2 IVF boluses before you left at 7 AM. Pt. continue to deteriorate and died 48 hours later despite combined endeavor of all services to salvage his hemodynamic collapse.

Your diagnosis (choose one).

A) Acute MI from plasma exchange therapy.
B) Acute septic shock due to use of steroid.
C) Side effect of propofol.
D) Acute renal failure from hypotension.
E) Ventilator associated pneumonia

Answer is C: Propofol infusion syndrome.


As propofol has gained enormous popularity in ICUs, it is extremely important to be aware of "Propofol infusion syndrome", particularly when drip is continued for more than 48 hours.

Syndrome consist of myocardial failure, metabolic acidosis, renal failure, lipemia, rhabdomyolysis, and hyperkalemia. Clues to "Propofol infusion sundrome" are unexplained lactate level, bradycardia and increasing need for pressors. It’s a clinical diagnosis.

Due to poorly understood reason, syndrome is associated with acute neurological illnesses or acute inflammatory diseases and receiving steroids in addition to propofol.

Also independent syndrome consist of bronchospasm, hypotension and anaphylactic type picture has been reported with start of infusion apart from "propofol infusion syndrome" above.

Some critics blame high lipid content of infusion for syndrome.

A) is wrong as acute MI is associated with IVIG theraphy for GBS and unlikely with plasma exchange. Also, this patient finished his therapy 2 days ago.

B) is wrong as there is no clear evidence of sepsis and short term use of steroid has less likely reason for acute sepsis. But please note that it is very important to practice aseptic technique while handling propofol.

D) is possible but extreme hypotension is unlikely to go unnoticed and doesn't explain all the clinical features.

E) VAP is not associated with this clinical picture