Extension of epidural blockade in labour for emergency Caesarean section using 2% lidocaine with epinephrine and fentanyl, with or without alkalinisation*

Abstract

In a randomised, double-blind study, we investigated rapid extension of epidural analgesia to surgical anaesthesia for emergency Caesarean section. Parturients receiving epidural analgesia in labour who subsequently required Caesarean section were given a test dose of 3 ml lidocaine 2% with epinephrine 1 : 200 000, followed 3 min later by 12 ml lidocaine 2% with epinephrine 1 : 200 000 and fentanyl 75 microg, to which was added 1.2 ml sodium bicarbonate 8.4% (bicarbonate group; n = 20) or saline (saline group; n = 20). Mean (SD [range]) time to surgical anaesthesia was less in the bicarbonate group (5.2 (1.5) [2-8] min) than the saline group (9.7 (1.6) [6-12] min; mean difference 4.5 min (95% CI 3.5-5.5) min; p < 0.001). Maternal side-effects and neonatal outcome were similar between groups. We conclude that pH-adjusted lidocaine 2% with epinephrine and fentanyl is effective for rapidly establishing surgical anaesthesia in patients with a functioning epidural catheter for labour who require emergency Caesarean section.

Epidural lidocaine‐bicarbonate‐adrenaline vs levobupivacaine for emergency Caesarean section: a randomised controlled trial*

“…1. Median (IQR [range]) time to reach a block to touch to T5 was 7 (6-9 [5][6][7][8][9][10][11][12][13][14][15][16][17]) min for lidocaine-bicarbonate-adrenaline and 14 (10-17 ) min for levobupivacaine. Time to reach a block to cold to T4 was also faster with lidocaine-bicarbonate-adrenaline (7 (5-8 [4][5][6][7][8][9][10][11][12][13][14][15][16][17]) min than with levobupivacaine (11 (9-14 [6-30]) min; p = 0.001).…”

“…The addition of sodium bicarbonate to lidocaine is thought to increase further the un-ionised fraction of lidocaine by increasing the pH, thereby promoting passage across the neuronal membrane [21]. This effect on the action of lidocaine action has been demonstrated in both elective [8,10,22] and emergency Caesarean section [14] but we are not aware of any comparisons between lidocaine-bicarbonate and bupivacaine or levobupivacaine in emergencies. The widespread use of lidocaine-bicarbonate mixtures for emergency Caesarean section has therefore been based on indirect evidence.…”

“…[14]. Goring-Morris and Russell [14], using lidocaine-fentanyladrenaline, found a median onset time for a block to T7 to touch of 13.8 min.…”

“…[14]. Goring-Morris and Russell [14], using lidocaine-fentanyladrenaline, found a median onset time for a block to T7 to touch of 13.8 min. Gaiser et al [13] reported onset times with lidocaine-bicarbonate-adrenaline for a block to T4 to cold of 4.4 (1.6) min.…”

“…This mixture has been described in the literature for both elective [8][9][10][11] and emergency [12][13][14] Caesarean section, and anecdotal contact with non-UK anaesthetists suggests that this mixture is also widely used around the world. However, although addition of bicarbonate to lidocaine results in rapid onset of anaesthesia for elective Caesarean section [11] and speeds the onset of lidocaine when used for extending labour analgesia for emergency Caesarean section [14], we are unaware of any studies of topping up an epidural for emergencies that compare lidocainebicarbonate mixtures with other agents available in the UK, although lidocaine without bicarbonate has been found to have no advantage over bupivacaine in this situation [3,15].…”