Sodium bicarbonate--an alternative to hyaluronidase in ocular anaesthesia for cataract surgery

Indian J Ophthalmol. 2000 Dec;48(4):285-9.


Purpose: To evaluate and compare the safety, efficacy and cost-effectiveness of 7.5% sodium bicarbonate buffered lidocaine (pH 7.2) with hyaluronidase mixed lidocaine (pH 4.6) for local anaesthesia in cataract surgery.

Methods: This prospective study comprised two parts. Part I: We evaluated the ocular and systematic anaesthetic safety and efficacy of 7.5% sodium bicarbonate buffered lidocaine on 112 consecutive patients undergoing cataract extraction with intraocular lens (IOL) implantation. At 12-week postoperative follow up final visual acuity and detailed fundus examination was done. Part II: It was conducted as a double blind, randomized comparative clinical trial involving 120 patients undergoing cataract surgery under retrobulbar anaesthesia. Patients were randomly assigned to one of the two groups: 60 eyes received 2 ml of 2% lidocaine with 1:200,000 epinephrine and 1 ml of 7.5% sodium bicarbonate, (0.299 mmol/ml); the remaining 60 eyes received 2 ml of 2% lidocaine with 1:200,000 epinephrine and 450 units of hyaluronidase (15 U/ml). In the event of incomplete akinesia, retrobulbar blocks were supplemented at 10 minutes. Onset and duration of anaesthesia and akinesia were assessed and compared in both groups.

Results: The pH-adjusted lidocaine group did not show any demonstrable variation in blood pressure (BP) or other systemic reaction. No anaesthesia-related adverse ocular effects were observed either during or after surgery. Thirty-one eyes (51.6%) achieved complete anaesthesia and akinesia within 5 minutes compared to 13 eyes (21.6%) in the hyaluronidase group. However, the overall mean onset time of anaesthesia and akinesia, repeat block rate and the duration of the anaesthesia were comparable in both the groups--p: 0.14). Twelve weeks postoperatively 88.39% of patients showed a best corrected visual acuity of 6/18 or better (73.21%-6/12 or better).

Conclusion: In this study, sodium bicarbonate buffered 2% lidocaine was found to be a safe and effective local anaesthetic, with reduced time of onset, and improved quality of both anaesthesia and akinesia. Sodium bicarbonate (7.5%) may be used as an alternative to hyaluronidase in ocular anaesthesia. It is readily available and is cost effective.

Publication types

  • Clinical Trial
  • Comparative Study
  • Evaluation Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Anesthesia, Local / methods*
  • Anesthetics, Local / administration & dosage*
  • Cataract Extraction*
  • Double-Blind Method
  • Drug Combinations
  • Epinephrine / administration & dosage
  • Female
  • Humans
  • Hyaluronoglucosaminidase / administration & dosage*
  • Lidocaine / administration & dosage*
  • Male
  • Middle Aged
  • Muscle Contraction / drug effects
  • Oculomotor Muscles / drug effects
  • Ophthalmic Solutions
  • Prospective Studies
  • Safety
  • Sodium Bicarbonate / administration & dosage*
  • Vasoconstrictor Agents / administration & dosage
  • Visual Acuity / drug effects


  • Anesthetics, Local
  • Drug Combinations
  • Ophthalmic Solutions
  • Vasoconstrictor Agents
  • Sodium Bicarbonate
  • Lidocaine
  • Hyaluronoglucosaminidase
  • Epinephrine