Plain or buffered lignocaine for local anaesthetic
Date First Published:
March 1, 2000
Last Updated:
November 14, 2001
Report by:
Russell Boyd, Consultant in Emergency Medicine (Manchester STEM)
Search checked by:
Bernard Foex, Manchester STEM
Three-Part Question:
In [patients requiring subcutaneous administration of local anaesthetic] is [buffered or plain lignocaine infiltration] better at [inducing less pain at the infiltration site]?
Clinical Scenario:
A 8 year old child has a 3cm wound requiring local anaesthesia prior to wound closure. While preparing a measured amount of lignocaine, you wonder if buffering with sodium bicarbonate will reduce the pain of administration.
Search Strategy:
Medline 1966 to 5/99 using the Winspirs interface.
Search Details:
[exp Lidocaine] AND [exp sodium bicarbonate OR exp buffers OR exp bicarbonates]
Outcome:
Search outcome 173 papers were identified of which 157 were irrelevant; 1 extra paper on update. The remanining 17 papers are shown in the table.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Pain reduction in local anaesthetic administration through pH buffering. Christoph RA, Buchanan L, Begalla K, et al. 1988, USA | 25 adult volunteers |
Double blinded randomised controlled clinical trial | Visual analogue derived pain scores | Significant reduction in pain with buffered lignocaine use | Markedly differing sites were used for each injection |
| Buffered versus plain lidocaine as a local anaesthetic for simple laceration repair. Bartfield JM, Gennis P, Barbera J, et al. 1990, USA | 91 adult patients with traumatic lacerations |
Double bind randomised controlled crossover clinical trial | Visual analogue scale derived pain scores | Buffered lignocaine is significantly less painful than plain | Actual pain scores and confidence limits not given |
| Reducing the pain of intradermal lignocaine injection by pH buffering. McGlone R, Bodenham A. 1990, UK | 20 volunteers |
Double blinded randomised controlled crossover trial | Visual analogue derived pain score | Significant reduction in pain scores using buffered lignocaine solutions | No confidence intervals |
| Buffered versus plain lidocaine for digital nerve blocks. Bartfield JM, Ford DT, Homer PJ. 1993, USA | 31 adult patients undergoing digital nerve block |
Double blinded randomised controlled crossover clinical trial | Visual analogue derived pain scores | Buffered lignocaine significantly less painful than plain | Again no pain scores and confidence limits given |
| Reducing the discomfort of lidocaine administration through pH buffering. Matsumoto AH, Reifsnyder AC, Hartwell GD, et al. 1994, USA | 150 patients undergoing interventional radiography procedures |
Double blinded randomised controlled clinical trial | Visual analogue derived pain scores | Significant reduction in pain after use of buffered lignocaine | Use of a crossover design may have been more appropriate to let each patient act as own control |
| Reducing the pain of local anaesthetic infiltration. Mader TJ, Playe SJ, Garb JL. 1994, USA | 32 adult volunteers receiving warm or room temperature buffered or plain lignocaine |
Double blinded randomised controlled crossover trial | Visual analogue derived pain scores | Significantly lower pain scores for warmed buffered lignocaine | Room temperature buffered lignocaine was no better than warm plain lignocaine. Significant results only occur if warmed and buffered. |
| Neutralizing pH of lidocaine reduces pain during Norplant system insertion procedure. Nelson AL. 1995, USA | 46 females undergoing subcutaneous contraceptive implant procedure |
Double blind randomised controlled crossover trial | Mean pain scores experienced on lidocaine and buffered lidocaine infiltration | 29% reduction in mean pain scores using buffered lidocaine | Neither actual scores nor confidence limits given so importance difficult to appreciate |
| Comparison of plain, warmed and buffered lidocaine for anaesthesia of traumatic wounds. Brogan GX Jr, Giarrusso E, Hollander JE, et al. 1995, USA | 45 adults with traumatic lacerations receiving plain, warmed or buffered lignocaine |
Single blinded randomised controlled clinical trial | Visual analogue scale derived pain scores | Warmed and buffered lignocaine were significantly less painful than plain lignocaine. No significant difference between warm or buffered lignocaine. | Single blinded |
| The use of pH adjusted lignocaine in controlling operative pain in the day surgery unit. Fitton AR, Ragbir M, Milling MA. 1996, UK | 30 patients undergoing bilateral pinnaplasty |
Double blinded randomised controlled crossover clinical trial | Visual analogue derived pain scores | Significant reduction in pain with buffered lignocaine | Operator blinding was not clearly identified |
| The effect of pH modification by bicarbonate on pain after subcutaneous lidocaine injection. Parham SM, Pasieka JL. 1996, USA | 42 adult volunteers |
Double blinded randomised controlled crossover volunteer study | Visual analogue derived pain | Significantly reduced pain on infiltration with buffered lignocaine | nil of note |
| Buffered lidocaine decreases the pain of digital anaesthesia in the foot Friedman HE, Jules KT, Springer K, et al. 1997, USA | 30 adult volunteers? |
Double blinded randomised controlled crossover trial | Visual analogue derived pain score | Significantly reduced pain of infiltration after use of buffered lignocaine | No confidence intervals |
| Pain of local anaesthetics: rate of administration and buffering. Scarfone RJ, Jasani M, Gracely EJ. 1998, USA | 42 adult volunteers receiving buffered and plain lignocaine at both slow and fast infusion rates |
Single (patient) blinded randomised controlled crossover trial | Visual analogue scale derived pain scores | No significant difference in pain scores generated after use of buffered and plain lignocaine | 2 different infusion rates used for buffered and plain. Numbers probably to small to identify a difference between plain vs buffered at each infusion rate |
| The effect of needle gauge and lidocaine pH on pain during intradermal injection. Palmon SC, Lloyd AT, Kirsch JR. 1998, USA | 40 adult volunteers receiving plain and buffered lignocaine using 2 differing needle guages |
Double blinded randomised crossover volunteer study | Visual analogue derived pain scores | Buffered lignocaine was significantly less painful | Timing of pain scoring after injection not stated |
| Pain reduction in lidocaine administration through buffering and warming. Colaric KB, Overton DT, Moore K. 1998, USA | 20 adult volunteers receiving warmed and room temperature plain lignocaine in addition to warmed and room temperature buffered lignocaine |
Double blinded randomised controlled crossover volunteer study | Visual analogue derived pain scores | Buffered lignocaine solutions were significantly less painful than warm or room temperature plain lignocaine | nil of note |
| Randomised controlled trial of pH buffered lignocaine with adrenaline in outpatient operations. Masters JE. 1998, NZ | 40 adult patients undergoing elective minor operations requiring local anaesthesia |
Double blinded randomised controlled crossover clinical trial | Visual analogue derived pain scores | Significant reduction in pain with use of buffered lignocaine | Non-standardised infiltration methods |
| Plain and buffered lidocaine for neonatal circumcision. Newton CW, Mulnix N, Baer L, et al. 1999 USA | 194 neonates undergoing circumcision |
Double blinded randomised controlled clinical trial | Crying as assessed by a Neonatal behavioural assessment score | No significant difference found between plain and buffered groups | Objectivity of a scoring neonatal crying |
| A randomised controlled trial of buffered lignocaine for local anaesthetic infiltration in children and adults with simple lacerations. Fatovich DM, Jacobs IG. 1999, Australia | 136 children undergoing dermal laceration repair in the emergency department 135 adults undergoing dermal laceration in the emergency department |
Double blind randomised controlled study | Visual Analogue Scores for pain on administration of local. Nurse and parent VAS for children | No significant difference in VAS scores between use of plain or unbuffered lignocaine | None significant |
Author Commentary:
One rare occasion in emergency medicine where PRCT's do exist! There is conflicting evidence here but the biggest study which was set in the ED suggests buffering not useful. The pro-buffer papers were smaller not as well conducted and were in volunteers or conducted in an elective setting.
Bottom Line:
In both children and indeed adults the evidence for buffered lignocaine in the acute setting does not support its mandatory use. Local expert advice should still hold.
References:
- Christoph RA, Buchanan L, Begalla K, et al.. Pain reduction in local anaesthetic administration through pH buffering.
- Bartfield JM, Gennis P, Barbera J, et al.. Buffered versus plain lidocaine as a local anaesthetic for simple laceration repair.
- McGlone R, Bodenham A.. Reducing the pain of intradermal lignocaine injection by pH buffering.
- Bartfield JM, Ford DT, Homer PJ.. Buffered versus plain lidocaine for digital nerve blocks.
- Matsumoto AH, Reifsnyder AC, Hartwell GD, et al.. Reducing the discomfort of lidocaine administration through pH buffering.
- Mader TJ, Playe SJ, Garb JL.. Reducing the pain of local anaesthetic infiltration.
- Nelson AL.. Neutralizing pH of lidocaine reduces pain during Norplant system insertion procedure.
- Brogan GX Jr, Giarrusso E, Hollander JE, et al.. Comparison of plain, warmed and buffered lidocaine for anaesthesia of traumatic wounds.
- Fitton AR, Ragbir M, Milling MA.. The use of pH adjusted lignocaine in controlling operative pain in the day surgery unit.
- Parham SM, Pasieka JL.. The effect of pH modification by bicarbonate on pain after subcutaneous lidocaine injection.
- Friedman HE, Jules KT, Springer K, et al.. Buffered lidocaine decreases the pain of digital anaesthesia in the foot
- Scarfone RJ, Jasani M, Gracely EJ.. Pain of local anaesthetics: rate of administration and buffering.
- Palmon SC, Lloyd AT, Kirsch JR.. The effect of needle gauge and lidocaine pH on pain during intradermal injection.
- Colaric KB, Overton DT, Moore K.. Pain reduction in lidocaine administration through buffering and warming.
- Masters JE.. Randomised controlled trial of pH buffered lignocaine with adrenaline in outpatient operations.
- Newton CW, Mulnix N, Baer L, et al.. Plain and buffered lidocaine for neonatal circumcision.
- Fatovich DM, Jacobs IG.. A randomised controlled trial of buffered lignocaine for local anaesthetic infiltration in children and adults with simple lacerations.