New paper published in the International Journal of Obstetric Anesthesia

Congratulations to CoMPRE visiting Professor Mike Wee, whose paper entitled, ‘Bacterial contamination of saline used for epidural procedures in an obstetric setting: a randomised comparison of two drawing-up techniques’ has been published in the International Journal of Obstetric Anesthesia.

This clinical study investigated one aspect of using an aseptic technique for epidural anaesthesia and found that the methods currently used for drawing up sterile saline for the procedure led to contamination with commensal  bacteria.  This has the potential to increase the risk of life threatening complications such as meningitis, epidural abscess and paralysis.  The authors recommend that integral sterile epidural saline is packaged in the epidural tray set or double wrapped to reduce the risk of contamination.

Infectious complications associated with central neuraxial blockade (spinals and epidurals) have potentially devastating consequences including paralysis, epidural abscess, meningitis and death.  This clinical study was designed to investigate one aspect of the aseptic technique for epidural analgesia and anaesthesia looking at the risk of contamination when drawing up the sterile saline used for the procedure using a needle technique or saline expressed onto a sterile tray.  We hypothesised that the tray technique would lead to an increase in the number of contaminated samples.

Methods: In labour rooms and before epidural catheter insertion, 110 samples of saline 20mL were randomly drawn up using either a hypodermic needle or the tray technique.  Equal amounts of saline were then inoculated into aerobic and anaerobic blood culture bottles.

Results.  Eleven percent of samples in the needle arm and 24% of samples in the tray arm grew commensal micro-organisms including coagulase negative Staphylococcus, Micrococcus luteus and Streptococcus viridans.  A two-sided Fisher’s exact test for categorical unpaired data showed no statistical difference between the two arms of the trial (P=0.13).

Conclusions.  Both techniques resulted in contamination of the saline samples with increased contamination using the tray technique but this was not statistically significant.  We recommend using sterile saline prepackaged in the epidural tray or double wrapped sterile ampoules to reduce the risk of contamination.