The surgical field ( visual analog scale [ VAS ] 9 [ range 2-10 ] compared with 6 [ range 2-10 ; P < .001 ] ; 0 = worst visual clarity , 10 = best visual clarity ) and the effluent fluid ( VAS 1 [ range 0-7 ] compared with 4 [ range 0-8 ; P < .001 ] ; 0 = clear , 10 = unclear ) were statistically significantly clearer in the vasopressin group .