Development and Evaluation of a Score to Predict Difficult Epidural Placement During Labor
Regional anesthesia and pain medicine
Phone number: 33 1 40 25 83 55 Fax number: 33 1 40 25 63 09 2 Abstract Background and Objectives: Difficult epidural placement (DEP) during labor may be distressing for the patient and may increase the risk of dural puncture. A score predicting DEP based on the combination of individual risk factors could identify high-risk patients. Therefore, this study aimed to identify risk factors for DEP and build a prediction score. Methods: 330 patients were prospectively included. More than one skin
... re than one skin puncture with Tuohy needle defined DEP. Dura puncture occurrence was recorded. The population was randomly split into a training (Tra) and a validation (Val) sets. In Tra, risk factors were identified with logistic regression and used to build a score defining 3 risk-groups. Model and score discrimination was assessed with the c-index and clinical usefulness of the score with decision curves. Results : DEP frequency was 30% (95%CI: 25-35). Dural puncture was more frequent in DEP patients (4% versus 0%, p=0.007). Three independent risk factors for DEP were identified: difficult interspinous space palpation (OR 6.1; 2.8-13.9), spinal deformity (OR 2.4; 1.1-5.3) and inability to flex the back (OR 3.0; 1.2-7.8). C-index of the model was 0.81 (0.74-0.88) in Tra and 0.78 (0.70-0.86) in Val. A 5-point score was created defining a low-(score 0), intermediate-(score 1-2) and high-risk groups (score 3-4) with predicted rates of DEP of 9.7%, 30.3% and 68.9%, respectively. The c-index of the score was 0.79 (0.72-0.86) in Tra and 0.76 (0.69-0.84) in Val. Decision curves support the clinical usefulness of the score. Conclusions: This study confirms risk factors for DEP and proposes a score predicting DEP. The score identifies high-risk patients that may benefit from an intervention to decrease DEP. This hypothesis should be evaluated in an impact study.