An audit of epidural blood patch after accidental dural puncture with a Tuohy needle in obstetric patients.

We report the results of a prospective audit of accidental dural puncture in 100 obstetric patients in a single tertiary referral institution during the period 1993 to 1999. The post dural puncture headache rate was 81%. Of the 81 parturients with post dural puncture headache, 58 (72%) received a therapeutic epidural blood patch, using 7 to 25 mL of autologous blood. After the initial blood patch, complete relief of headache was obtained in 67% and complete or partial relief in 95%. However, severe headache returned in 31% and 28% received more than one blood patch. The incidence of complete relief of headache with one blood patch or more was 50%, with 38% achieving partial relief and 12% having unrelieved headache. There was no significant association between volume of blood used for blood patch and success rate. The initial rate of resolution of headache did not differ significantly between parturients receiving a blood patch within 48 h of dural puncture and after 48 h (P =0.70). However, in the former group, the incidence of recurrent headache was significantly higher (59% versus 11%, P<0.001).