Wang LP et al. Anesthesiology. 91(6):1928-36, 1999 Dec.

Reviewed by: James Fletcher, MD

Summary:

• This Danish study comments on previous data reporting an incidence of 0/9,232 cases in Sweden, 2/13,000 in Germany, and 3% in a small US study using epidurals for long term management of chronic pain.
• The  present multicenter prospective study collected data on epidural abscesses as they occurred.  A denominator was calculated from the number of epidurals placed at each participating hospital.

• 17,372 epidurals were placed during the study period.
• 12 possible abscesses were found. 9 were real (2 were subcutaneous infections, 1 a complication from catheter placement):
• Incidence was 1:1930. By type of hospital:
• 1:5661 at university hospitals
• 1:796 at community hospitals.
• Catheterization time was 11.2 ±3.6 days, median 6 days, (range 3-31 days)
• Level: 5 thoracic, 4 lumbar
• Indications: 6 post-op pain, 2 cancer pain, 1 trauma pain
• Symptoms: 1 meningitis, 5 febrile, 6 signs of local infection, 6 localized back pain, 7 paraplegic symptoms
• Time to diagnosis from onset of symptoms: 8.2 ±9.9 days, median 5 range 1-32 days
• Staph aureus in 5 pts, coag neg staph in one, no growth in 2
• 7 had decompression of the cord, 2 managed with antibiotics
• No relation to uncomplicated/complicated insertion of epidural

• This paper is interesting in that it produces for the first time an assessment of risk (important for patient information).
• If the risk is 1:2000, then 
• an anesthesiologist in a busy practice is likely to 'cause' one in their lifetime.
• also at this level of risk, one may occur every couple of years in an obstetric department such as ours.
• However, none of the abscesses occurred in an obstetric patient, they were all between 40 and 70, most towards the older end of the range. No denominator for obstetric epidurals is given