Tooth extraction, bleeding and pain control.

Local anaesthesia is used routinely in dental surgery; it is effective in both pain control and--through the vasoconstrictors often contained within it--the reduction of bleeding. The extraction of deciduous teeth under general anaesthesia is often carried out without these local effects. There are no previous studies to investigate the combined effect of local anaesthesia with general anaesthesia on blood loss and pain control. A randomised, controlled clinical trial was carried out with one hundred children aged 3-5 years. Ethical approval and informed consent were obtained. Surface anaesthetic cream (EMLA) was placed on the hand into which the intravenous access was to be placed. One to two ml of blood was taken at the time of induction as a baseline of the patient's level of haematin pigment. Children in the experimental group were given one quarter of a cartridge (0.5 ml) of local anaesthetic containing epinephrine (1:80,000) in each quadrant before tooth extraction; all blood in swabs, suction equipment and disposables was collected and digested with NaOH. The children were observed for 11 minutes post-operatively for any signs of distress. Total blood loss was calculated by comparison of the baseline sample and the shed blood digests. This study showed that using local anaesthesia for dental extractions under general anaesthesia was associated with decreased blood loss (p = 0.001). The second finding--which has not been reported before--was that this use of local anaesthesia was shown to cause distress to this age group of children upon recovery from the general anaesthetic (p <0.0001). The use of local anaesthetic in this situation provided a useful reduction in post-operative bleeding. However, its use was associated with greater post-operative distress.