The epidural test dose: a review

Abstract

This review systematically examines the literature on the ability of the classical epidural test dose and other strategies to detect intravascular, intrathecal, or subdural epidural needle/catheter misplacement. For detection of simulated intravascular misplacements, a sensitivity (S) and a positive predictive value (PPV) > or =80 demonstrated by at least two randomized controlled trials coming from two different centers were determined for the following tests and patient populations: Nonpregnant adult patients = increase in systolic blood pressure (SBP) > or =15 mm Hg (S = 80-100 and 93-100; PPV = 80-100 and 83-100) or either an increase in SBP > or =15 mm Hg or an increase in heart rate > or =10 bpm after the injection of 10 (S = 100; PPV = 83-100) or 15 microg of epinephrine (S = 100; PPV = 83-100); pregnant patients = sedation, drowsiness, or dizziness within 5 min after the injection of 100 microg of fentanyl (S = 92-100; PPV = 91-95); and children = increase in SBP > or =15 mm Hg after the injection of 0.5 microg/kg of epinephrine (S = 81-100; PPV = 100). Conversely, more studies are required to determine the best strategies to detect intrathecal and subdural epidural needle/catheter misplacements in these three patient populations.