STUDY OBJECTIVE: To assess the factors affecting the distance from skin to epidural space. DESIGN: Prospective observational study of consecutive cases over a 2-year period. SETTING: Inpatient obstetric unit in a French university hospital. PATIENTS: 2,123 consecutive term parturients who received epidural anesthesia for cesarean section or epidural analgesia for labor and vaginal delivery. INTERVENTIONS: At the time of epidural puncture, the interspace used and the patient's posture (sitting or left lateral decubitus) were recorded, and the distance from 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 index (BMI; weight/height2), presence of scoliosis] and technical factors (interspace, patient's posture at puncture) versus DS-ES was investigated using multiple regression analysis. DS-ES correlated positively with the parturient's weight and BMI. In addition, DS-ES was significantly greater when epidural puncture was performed in the lateral position as compared with the sitting position. CONCLUSION: Both the patient's weight and position during epidural needle placement are important factors influencing DS-ES. A change from the sitting to the lateral position may increase DS-ES, causing catheter dislodgment and consequent inadequate analgesia. Clinical studies relating DS-ES to inadequate analgesia must take these factors into account.
STUDY OBJECTIVE: To assess the factors affecting the distance from skin to epidural space. DESIGN: Prospective observational study of consecutive cases over a 2-year period. SETTING: Inpatient obstetric unit in a French university hospital. PATIENTS: 2,123 consecutive term parturients who received epidural anesthesia for cesarean section or epidural analgesia for labor and vaginal delivery. INTERVENTIONS: At the time of epidural puncture, the interspace used and the patient's posture (sitting or left lateral decubitus) were recorded, and the distance from 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 index (BMI; weight/height2), presence of scoliosis] and technical factors (interspace, patient's posture at puncture) versus DS-ES was investigated using multiple regression analysis. DS-ES correlated positively with the parturient's weight and BMI. In addition, DS-ES was significantly greater when epidural puncture was performed in the lateral position as compared with the sitting position. CONCLUSION: Both the patient's weight and position during epidural needle placement are important factors influencing DS-ES. A change from the sitting to the lateral position may increase DS-ES, causing catheter dislodgment and consequent inadequate analgesia. Clinical studies relating DS-ES to inadequate analgesia must take these factors into account.
Authors: C E Nightingale; M P Margarson; E Shearer; J W Redman; D N Lucas; J M Cousins; W T A Fox; N J Kennedy; P J Venn; M Skues; D Gabbott; U Misra; J J Pandit; M T Popat; R Griffiths Journal: Anaesthesia Date: 2015-05-07 Impact factor: 6.955