Letters Section Editor: Robert M. Golub, MD, Senior Editor.
To the Editor: Regarding the Clinical Crossroads article by Dr Sachs,1 we would like clarification of the medication for the test dose for the epidural anesthesia that was used for labor analgesia. While indicated as 3 mL of 1% to 5% lidocaine, this is an unfamiliar description. A common test dose is 45 to 60 mg of lidocaine (equivalent to 3 mL of 1.5% or 2% lidocaine) with 1:200 000 epinephrine dilution. The rationale for a test dose is to detect an inadvertent intrathecal or intravenous placement of the epidural catheter. The abrupt drop in blood pressure (174/104 mm Hg to 53/33 mm Hg) is not the expected response with an appropriately placed epidural tip and is suggestive of a possible intrathecal catheter location. It is unclear whether this was excluded prior to initiating epidural analgesia.
Sander-Prather M, De Ruyter M. A Woman With Fetal Loss. JAMA. 2006;295(4):386-387. doi:10.1001/jama.295.4.386-b