PARTURIENTS POSTURE DURING EPIDURAL PUNCTURE AFFECTS THE DISTANCE FROM SKIN TO EPIDURAL SPACE

Study Objective: To assess the factors affecting the distance from ski n to epidural space. Design: Prospective observational study of consec utive cases over a 2-year period. Setting: Inpatient obstetric unit :i n a French university hospital. Patients: 2,123 consecutive term partu rients who received epidural anesthesia for cesarean section or epidur al analgesia for labor and vaginal delivery. Interventions: At the tim e of epidural puncture, the interspace used and the patient's posture (sitting or left lateral decubitus) were recorded, and the distance fr om the skin to the epidural space (DS-ES) was measured to the nearest 0.5 cm using a marked epidural needle. Measurements and Main Results: The relationship between patient factors [height, weight, body mass in dex (BMI; weight/height(2)), presence of scoliosis] and technical fact ors (interspace, patient's posture at puncture) versus DS-ES was inves tigated using multiple repression analysis. DS-ES correlated positivel y with the parturient's weight and BMI. In addition, DS-ES war signifi cantly greater when epidural puncture was performed in the lateral pos ition as compared with the sitting position. Conclusion: Both the pati ents weight and position. during epidural needle placement are importa nt factors influencing DS-ES. A change from the sitting to the lateral position may increase DS-ES, causing catheter dislodgment and consequ ent inadequate analgesia. Clinical studies relating DS-ES to inadequat e analgesia must take these factors into account.