Accidental dural puncture rates in UK obstetric practice

Area of Science:

• Anesthesiology
• Obstetrics
• Epidemiology

Background:

• Headache post-epidural analgesia is a frequent complication.
• Accidental dural puncture rates vary significantly across institutions and techniques.
• Effective audit of dural puncture is essential for patient safety and informed consent.

Purpose of the Study:

• To assess the extent of audit for accidental dural puncture in UK obstetric units.
• To determine dural puncture rates and techniques used for epidural space identification.
• To compare the safety of different loss of resistance techniques.

Main Methods:

• A questionnaire was distributed to 257 UK obstetric units regarding epidural procedures and dural punctures (1991-1995).
• Data on annual epidural volume, loss of resistance technique, and accidental dural puncture rates were collected.
• Statistical analysis compared dural puncture rates based on epidural volume and loss of resistance medium (saline vs. air).

Main Results:

• 191 units responded (74%), with 104 providing dural puncture rate data.
• Dural puncture rates were inversely proportional to the number of annual epidurals performed (3.6% for <300 vs. 0.19% for >1000).
• Loss of resistance with saline yielded a lower dural puncture rate (0.69%) than with air (1.11%, P<0.001).

Conclusions:

• Audit of dural puncture requires improvement in many UK obstetric centers.
• The accidental dural puncture rate appears to be under-reported in this survey.
• Loss of resistance using saline is demonstrably safer than using air for detecting the epidural space.