The systemic absorption of adrenaline from posterior segment infusion during vitreoretinal surgery

Background/purpose Adrenaline infused into the posterior segment of the eye during vitreoretinal surgery may be absorbed and give rise to unwanted car diovascular effects. We sought to establish whether significant amounts of adrenaline are systemically absorbed. Methods This study was prospective and double-masked, with patients randomi sed into two groups. The first group received a posterior segment infusion containing Hartmann's solution alone (Hs group) and the second group receiv ed a posterior segment infusion of Hartmann's solution containing 0.5 ml of 1:1000 (0.5 mg) adrenaline per 500 ml (Hs+Ad group). Pre-medication and an aesthetic techniques were standardised for all patients. Venous blood sampl es were collected prior to induction, 5 min following intubation and 5, 10, 15 and 30 min following the commencement of the infusion. Samples were ana lysed for adrenaline levels using high-performance liquid chromatography. Results Ten patients were studied: 4 in the Hs group and 6 in the Hs+Ad gro up. The mean dose of adrenaline administered in the Hs+Ad group was 655.08 nmol (0.12 mg). The median serum adrenaline level following infusion for th e Hs+Ad group was 0.15 nmol/l (LQ = 0.100, UQ = 0.360) and the median serum adrenaline level for the Hs group was 0.10 nmol/l (LQ = 0.100, UQ = 0.350) . There was no overall statistical difference in the levels of serum adrena line between the two groups, and furthermore adrenaline levels remained wit hin physiological parameters for both groups. Conclusion There does not appear to be significant adrenaline absorption fr om posterior segment infusion. Continued caution should be exercised, howev er, as idiosyncratic reactions may still occur.