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Three Part Question

In [women with an epidural for labour who require emergency caesarean section] is [lignocaine or ropivicaine superior to bupivicaine] in [producing rapid, adequate anaesthesia for surgery]?

Clinical Scenario

A 25yr old pregnant woman is admitted to delivery suite in early labour and has a lumbar epidural sited for analgesia. Four hours later the CTG shows prolonged, late decelerations (fetal distress) and clinical examination demonstrates cervical dilatation of only 7cm. The woman is transferred to obstetric theatre for an emergency (Grade 2) caesarean section. The epidural has provided excellent pain relief in labour.

Search Strategy

Embase (1980 – present) and (Medline 1950 – present) using NHS Evidence Health Information Resources

Embase
[exp cesarean section] AND [exp emergency surgery] AND ([local anesthetic agent] OR [exp lidocaine] OR [exp ropivicaine] OR [exp bupivicaine])

Medline
[exp cesarean section] AND [exp emergencies] AND ([exp anesthetics, local] OR [exp lidocaine] OR exp bupivicaine])

Search Outcome

A total of 97 papers were identified, of which 5 were duplicate results. From the remaining 92 unique papers, 3 were deemed relevant. Any papers examining the role of epidural opiates were excluded.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Lucas DN, Ciccone GK, Yentis SM 1999 UK	Healthy nulliparous labouring women with singleton pregnancies and low dose labour epidurals requiring epidural augmentation for emergency Caesarean section. 3 Groups: Bupivicaine 0.5% 20ml Bupiv 0.5%/Lignocaine 2% 50:50 20ml Lignocaine 2% 20ml (all lignocaine with adrenaline 1:200 000	Prospective, double-blind randomised control trial	Time to T4 Block (Cold)	No significant difference	Used loss of cold sensation rather than touch to test height of block.
			Visual Analogue Score for pain (patient)	No significant difference
			Visual Analogue Score for pain (anaesthetist)	No significant difference
			Intraoperative fluid requirement	No significant difference
			Ephedrine requirements	No significant difference
			Apgar Scores	No significant difference
			Number of patients requiring supplementary analgesia/anaesthesia	No significant difference
			Number of patients requiring conversion to GA	Bupivicaine group: 0/26. Bupivicaine/Lignociane group: 0/29. Lignocaine group: 3/28 (p=0.04)
Sanders RD, Mallory S, Lucas DN, Chan T, Yeo S, Yentis SM 2004 UK	Primiparous women with a previously sited epidural catheter requiring emergency Caesarean section. 2 Groups: Ropivicaine 0.75% 20ml Bupivicaine 0.5% 20ml	Prospective, double-blind randomised control trial (1b)	Time to T4 Block (cold)	No significant difference	Small sample size (n=44)and used loss of cold sensation rather than touch to test height of block.
			Visual Analogue Score for pain (patient)	No significant difference
			Visual Analogue Score for pain (anaesthetist)	No significant difference
			Intraoperative fluid requirements	No significant difference
			Ephedrine requirements	No significant difference
			Number of patients requiring supplementary analgesia/anaesthesia	Bupivicaine group: 9/21. Ropivicaine group: 2/23 (p=0.01)
			Number of patients requiring conversion to GA	No significant difference
AllamJ, Malhotra S, Hemingway C, Yentis SM 2008 UK	ASA 1 or 2 women with singleton pregnancies receiving effective analgesia in labour from lumbar epidural who went on to emergency Caesarean section. 2 Groups: Lignocaine/Bicarbonate/Adrenaline (1.8%/0.76%/1:200 000) 20ml Levobupivicaine 0.5% 20ml	Prospective randomised control trial	Time to T5 Block (touch)	Lignocaine group: 7min vs Bupivicaine group: 14min (median) (p=0.00004)	The authors did not separate out the number of patients requiring conversion to GA from those requiring supplementary analgesia/anaesthesia. As only the lidocaine group was alkalinised, it is uncertain whether the faster onset in this group was due to the lidocaine or the bicarbonate.
			Time to T4 Block (cold)	Lignocaine group: 7min vs Bupivicaine group: 11min (median) (p=0.001)
			Pain score	No significant difference
			Maternal sedation score	No significant difference
			Intraoperative fluid requirements	No significant difference
			Number of patients requiring supplementary analgesia/anaesthesia	No significant difference

Comment(s)

Only three studies with relatively small patient numbers have examined the differences between local anaesthetic agents used in augmentation of epidural block for emergency caesarean section. All three studies however were randomised controlled trials and used clinically relevant endpoints. No trials have compared plain lignocaine to bupivicaine or levobupivicaine to bupivicaine. Neither ropivicaine nor lignocaine (with adrenaline) produced more rapid surgical anaesthesia compared to bupivicaine. Patients receiving ropivicaine are less likely to require supplementation during surgery. Patients augmented with lignocaine (with adrenaline) only are more likely to require conversion to general anaesthesia. Alkalinised lignocaine produces a more rapid onset block than levobupivicaine for emergency caesarean section. This advantage may be offset by more lengthy preparation times. Preservative free sodium bicarbonate is only commonly available in a Minijet® syringe format which may have significant cost (10ml 8.4% = £6) implications or sterility concerns if the same syringe is used repeatedly. Delay may be avoided by advanced preparation of drugs, although sodium bicarbonate is unstable with epinephrine containing mixtures. There is also the concern that complex mixtures are more likely to give rise to drug preparation errors.

Clinical Bottom Line

Ropivicaine is superior to bupivicaine in producing a block less likely to require supplementation but neither it nor lignocaine achieve surgical anaesthesia any faster than bupivicaine.

References

1. Lucas DN, Ciccone GK, Yentis SM Extending low-dose epidural for emergency Caesarean section. A comparison of three solutions Anaesthesia (54) 1999; 1173-1177
2. Sanders RD, Mallory S, Lucas DN, Chan T, Yeo S, Yentis SM Extending low-dose epidural analgesia for emergency Caesarean section using ropivicaine 0.75%. Anaesthesia (59) 2004; 988-992
3. AllamJ, Malhotra S, Hemingway C, Yentis SM Epidural lidocaine-bicarbonate-adrenaline vs levobupivicaine for emergency Caesarean section: a randomised controlled trial Anaesthesia (63) 2008; 243-249