Obstetric epidural test doses: a survey of UK practice.
BACKGROUND
With the advent of low-dose epidural analgesia in labour, the content of the test dose has once again become the subject of debate.


METHODS
A postal survey of 500 members of the Obstetric Anaesthetists' Association was conducted in 1999-2000, assessing the use of test doses during epidurals in labour and for caesarean section.


RESULTS
There was a 67% response rate. Test doses are used in labour, at elective caesarean section and before epidural top-up for emergency caesarean section, by 90%, 93% and 37%, respectively. There was large variation in both drugs and doses. During labour, doses of bupivacaine range from 3 to 20 mg and of lidocaine 15 to 90 mg. There has been a three-fold increase in the use of low-dose local anaesthetic test doses since a previous national survey in 1997. The size of local anaesthetic test doses used at caesarean section is also variable. Epinephrine is used in 5% of labour, 14% of elective and 34% of emergency caesarean sections. Signs and symptoms that are commonly sought after test doses include somatic motor block, blood pressure change, sensory effect and symptoms from systemic local anaesthetic. The effect of the test dose is usually assessed after 5 min.


CONCLUSIONS
There is no consensus about the nature of the ideal test dose in obstetric anaesthesia. There is a trend to use less concentrated test doses during labour. Doses that risk a high block if given spinally are still used. Epinephrine, aspiration testing and cardiovascular monitoring are uncommon.
Gardner
I C
IC
St Michael's Hospital, Bristol, UK.
Kinsella
S M
SM
D015360:Analgesia, Epidural / Q000379:methods*; D000773:Anesthesia, Obstetrical / Q000379:methods*; D002585:Cesarean Section; D004630:Emergencies; D004837:Epinephrine; D005260:Female; D006801:Humans; D011247:Pregnancy; D013997:Time Factors
D004837:Epinephrine