DOES WARMING OF ANESTHETIC SOLUTIONS IMPROVE ANALGESIA AND AKINESIA IN RETROBULBAR ANESTHESIA

Purpose: The authors assess the effect of warming local anesthetic sol utions on pain of injection and on bulbar akinesia and analgesia of re trobulbar anesthesia (RBA), Methods: Seventy patients undergoing RBA f or cataract surgery were enrolled in a prospective, double-blind trial . They were allocated randomly to receive 5 mi either warm (37 degrees C) or cold (20 degrees C) anesthetic solution for RBA, Additionally, O'Brien's method was used to create an akinesia of the orbicularis ocu li muscle. The following data were collected before and 20 minutes aft er retrobulbar injection: pain of injection, eye motility (Kestenbaum test), and corneal sensitivity (0: no sensitivity; 1, sensitivity rema ining) at four different sites. The pain of injection was registered u sing an ordinal analogous scare before and immediately-after the injec tion. Furthermore, data acquisition included any possible side effects and the bulbar length, measured with ultrasound. Results: The score f or injection pain (4.5 +/- 2.3 points), horizontal eye motility (0.2 /- 0.8 mm), vertical eye motility (0.9 +/- 2.1 mm) all were lower for the warm group in comparison to the cold group (average pain score: 5. 2 +/- 2.6 points; horizontal eye motility: 0.7 +/- 1.6 mm; vertical ey e motility: 1.2 +/- 2.0 mm). Two patients in the warm group and four p atients in the cold group had remaining corneal sensitivity. None of t he differences were significant, Conclusions: Data indicate no signifi cant difference in bulbar analgesia and akinesia after RBA between inj ections of warm and cold anesthetic solutions.