Wednesday October 11, 2006


Q; 42 yr old male admitted with Guillain-Barré Syndrome and intubated due to rapidly falling vital capacity. Pt 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 on ICU shift on night of day 7, you noticed some downward trend on BP 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 went unnoticed as this was the most stable patient in unit. Also pulse ox now trending in 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 pt. has NSTE MI with Troponin-I of 7.1. You discuss case with primary service and now cardiology, nephrology and ID services are on case. Pt continue to deteriorate and died 48 hours later despite combined endeavors 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.



Ans is (C): Propofol infusion syndrome

As propofol has gained enormous popularity in ICUs, it is extremely important to be aware of "Propofol infusion syndrome" when drip is continued for more than 48 hours with dose above 5mg/kg/hr. 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. Some critics blame high lipid content of infusion for syndrome.

Discussing choices:

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 it is unlikely that extreme hypotension will go unnoticed in ICU.

E - VAP is not associated with this clinical picture


Reference:

Ann Pharmacother. 2002 Sep;36(9):1453-6, The Lancet 2001;357:117-118, Intensive Care Med. 2003 Sep;29(9):1417-25.

Bonus Pearl: Propofol infusion is noticed to turn colour of urine green. It is a benign potential side effect of Propofol. Recognition of this side effect is important as it averts unnecessary further workup and limits medical expenditures.