ABSTRACT
The choice of an ideal fluid administered post trauma and its subsequent influence on coagulation still poses a clinical dilemma. Hence, this study was designed to assess the influence of in vivo hemodilution with various fluid preparations [4% gelatin, 6% hydoxyethyl starch [HES], Ringer's lactate, 0.9% normal saline] on coagulation using standard coagulation parameters and real-time thromboelastography [TEG] in patients undergoing elective surgery post trauma. In a randomized, double-blind study, 100 patients of either sex and age, belonging to ASA Grades I and II, scheduled for elective surgeries were allocated into four groups of 25 each according to the type of fluid infused. Group G [4% gelatin], Group N [0.9% normal saline], Group R [Ringer's lactate], and Group H [6% HES] received preloading with 1 L of fluid according to the group. The coagulation status of the patients was assessed during perioperative period [before surgery, after fluid preloading, and at the end of the surgery] using both conventional coagulation analysis and TEG. Analysis of variance [ANOVA], post hoc and Pearson Chi-square test were used. In all the patients preloaded with gelatin, there was a significant increase in prothrombin time index [PTI; 14.88 +/- 0.90 vs. 13.78 +/- 3.01, P<0.001] and international normalized ratio [INR; 1.12 +/- 0.09 vs. 1.09 +/- 0.19, P<0.05] compared to the baseline value. An increase was observed in these parameters in the postoperative period also. In the HES group, there was statistically significant increase in PT time [15.70 +/- 1.51 vs. 13.74 +/- 0.75, P=0.01] and INR [1.20 +/- 0.15 vs. 1.03 +/- 0.17, P<0.001] as compared to the baseline. In the intergroup comparisons, the patients preloaded with HES had a significant increase in INR [1.20 +/- 0.15 vs. 1.12 +/- 0.09, P=0.04] and reaction time [R time; 6.84 +/- 2.55 min vs. 4.79 +/- 1.77 min, P=0.02] as compared to the gelatin group. The fall in coagulation time [k time; 2.16 +/- 0.98 vs. 3.94 +/- 2.6, P=0.02], rise in maximum amplitude [MA; 61.94 +/- 14.08 vs. 50.11 +/- 14.10, P=0.04], and rise in A20 [56.17 +/- 14.66 vs. 43.11 +/- 14.24, P=0.05] were more in patients preloaded with RL as compared to the HES group. 100% patients in the gelatin group, 84.2% patients in the NS group, 94.4% patients in the RL group, and 66.7% patients in the HES group had hypocoagulable [R time > 14 min] state in the postoperative period. Crystalloids are optimal volume expanders in trauma, with RL having beneficial effects on coagulation system [decrease in k time and increase in MA and A20]. Among the colloids, HES 6% [130/0.4] affects coagulation parameters [increase in PTI, INR, R time, k time] more than gelatin. Trial registration [protocol number-IEC/NP-189/2011]