Techniques for identifying the epidural space: a survey of practice amongst anaesthetists in the UK.

A postal survey of all UK members of the Obstetric Anaesthetists' Association was carried out to ascertain their preferred method for identifying the epidural space in obstetric and non-obstetric patients. Over 1200 questionnaires were returned (79.3% response rate). In obstetric patients, the single most common technique (used by 58% of anaesthetists) was continuous advancement of the epidural needle and loss of resistance with saline, followed by intermittent needle advancement with air (21%). A minority of respondents used other variants, including intermittent advancement with saline (16%) and continuous advancement with air (4%). Consultant anaesthetists showed greater variety in techniques used than did trainees (p < 0.001). Less than 5% of respondents used a paramedian approach, and these were almost exclusively senior staff. Only 48% of anaesthetists said they would try an alternative if they experienced difficulty with their preferred technique. A similar pattern was seen for lumbar epidurals in non-obstetric surgical patients (89% used the same technique as in obstetrics), although for thoracic epidurals, 23% used a different technique to that which they would use for obstetrics, and the paramedian approach was more popular (21%). When inserting lumbar epidurals to supplement general anaesthesia in surgical patients, 18% of anaesthetists said they usually performed the block with the patient asleep, whereas for thoracic epidurals, this figure fell to 14%.