///2010 Abstract Details
2010 Abstract Details2018-05-01T17:52:49+00:00

HOW USEFUL ARE CLINICAL CRITERIA FOR PDPH DIAGNOSIS AFTER EPIDURALS?

Abstract Number: 62
Abstract Type: Original Research

Pamela Angle MD, MSc1 ; Marek Gawel MD2; Pat Morley-Forster MD3; Jean Kronberg MD, PhD4; Joanne Douglas MD5; Canadian PDPH Collaborative PDPH6

Introduction: Postdural puncture headache (PDPH) is currently diagnosed using varying criteria in anesthesia studies, including study-specific as well as formal criteria set out by the International Headache Society (IHS). We prospectively compared the usefulness of IHS criteria vs. a formal study definition for PDPH diagnosis in a large multi-centered RCT.

Methods: Following REB approval, 1,080 women requesting labor epidural analgesia were randomized to receive 19g vs. 17/18g Tuohy-type needle in 4 centers across Canada. The primary outcome was PDPH diagnosed using a formal study definition applied in a standardized fashion by an external blinded adjudicating body. Interviews were conducted by trained staff using standardized data forms on days 1, 3 and 14 post epidural placement. Data collected for any woman reporting a headache with any suggestion of movement associated-worsening < 14 days of epidural placement was sent for adjudication. The headache specialist and a single matched anesthesiologist rated PDPH in a given patient. 1st pass and final agreement were obtained for both sets of diagnostic criteria. Items which caused inter-rater discordance were identified. All adjudicated patients were interviewed at least up to 6 wks. Those with adjudicated positive PDPH (study definition only) were followed for up to 1 yr. Staff at study sites were blind to both needle and adjudicators diagnoses and diagnosed/treated headaches at their discretion.

Results: A total of 1080 women were randomized; 184 were sent for adjudication. Of these, 25 women received a final diagnosis of PDPH using the study definition, 16 were diagnosed using IHS criteria and 6 were diagnosed by blinded staff at study sites <14days. A test of correlated proportions showed that the PDPH study definition was more sensitive for diagnosis than IHS criteria (McNemars test; p=0.02). 1st pass consensus for PDPH diagnosis using the study definition was better (22/25(kappa 0.93, 95%CI 0.85, 1.0(very good)) than 1st pass consensus using IHS criteria (9/16(kappa 0.70, 95%CI 0.49, 0.92(good)). Inter-rater discordance using IHS criteria occurred in the following areas: length of time (<5days) allowed for diagnosis: 2/7; Dural Puncture occurred: 2/7; symptomatic criteria: 5/7. Inter-rater discordance using the study definition occurred in the following areas: Headache symptoms (posturality): worsening 15min 2/3; improved in 15min: 1/3; length of time for diagnosis (<14days):1/3;symptom persistence 1/3. One patient, adjudicated negative by both criteria, developed a postural headache on day 15 and responded to a single epidural blood patch.

Discussion: Outcome assessment in PDPH research requires reliable and valid measurement. IHS criteria have issues with face and content validity in patients receiving epidural analgesia. PDPH diagnosis using our formal study definition proved to have greater sensitivity and inter-rater agreement amongst experts compared with IHS criteria.

SOAP 2010