Effect of epidural analgesia on change in Mallampati class during labour.

Mallampati class has been shown to increase during labour. Epidural analgesia might influence this change. The aim of our study was to compare the change in Mallampati class during labour in parturients who did and did not receive epidural analgesia and study the association of these changes with pre-defined clinical characteristics. We performed a prospective observational study of 190 parturients. Using standard methodology, photographs of the upper airway were taken with a digital camera during early labour and within 90 min of delivery. Two to three consultant anaesthetists, blinded to the origin of the photographs, evaluated the images obtained and assigned a Mallampati class to each. Overall, Mallampati class increased in 61 (32.1%), decreased in 18 (9.5%) and did not change in 111 (58.4%) parturients (p<0.001). The proportions of parturients in the epidural and non-epidural groups who demonstrated an increase, decrease and no change in Mallampati class were similar. Of the relationships between change in Mallampati class and the other factors studied, only the total dose of epidural levobupivacaine during labour demonstrated a weak positive correlation 0.17 (p=0.039) with Mallampati class. This study confirms that labour is associated with an increase in the Mallampati class in approximately one third of parturients. Our findings indicate that having an epidural does not influence the likelihood of a change in Mallampati class during labour.