Experimental validation of the CompuFlo® epidural controlled system to identify the epidural space and its clinical use in difficult obstetric cases

•The CompuFlo® device identifies the ligamentum flavum and the epidural space.•It was associated with successful epidural block.•This technology may assist the trainee in difficult cases. This prospective study was designed to validate the CompuFlo® device and to assess its use in difficult epidural placement. In the first part of the study, 30 parturients requesting labor epidural analgesia were recruited. The block was performed by an expert anesthesiologist, with the Tuohy needle connected to the CompuFlo® device to evaluate the agreement between the anesthesiologist’s reported sensation and the variation of pressure recorded by the CompuFlo®. In the second part of the study, 56 consecutive parturients, for whom at least two complete needle reinsertions were made by trainees during epidural placement for labor analgesia, were enrolled. CompuFlo® was used as a rescue tool for the subsequent attempt. In all cases epidural analgesia was successful and no complications were noted. There was a good correlation between the operator’s feelings and the delta of pressure recorded by the CompuFlo®, for both identification of the ligamentum flavum and of the epidural space (Rho = 0.79; tau = 0.67). In the second part of the study, all the difficult blocks performed with the CompuFlo® were successful after a single attempt. The pressure curves of false loss-of-resistance were significantly different from the true loss-of-resistance (P