The effects of fluid resuscitation with different crystalloid-colloid ratio on extravascular lung water index in severe acute pancreatitis

Objective To investigate the effects of fluid resuscitation with different crystalloid-colloid ratio on extravascular lung water (EVLW) in patients with severe acute pancreatitis (SAP). Methods Clinical data of 24 SAP patients ,who had undergone intrathoracic blood volume index (ITBVI ＜750 ml/m2),were analyzed retrospectively, in Department of Critical Care Medicine in the First Affiliated Hospital of Shenzhen University, during January of 2009 to December of 2010. ITBVI 850 - 1 000 ml/m2 was confirmed the end criterion of the end point of resuscitation. Low crystalloid-colloid ratio group (n = 13) and high crystalloid-colloid ratio group (n = 11) were divided according to crystalloid-colloid ratio (3∶1) as the borderline. Hemodynamic parameters, extravascular lung water index (EVLWI), oxygenation index (PaO2/FiO2), bladder pressure (ICP) and B-type natriuretic peptide (BNP) were observed at the time point of before fluid resuscitation, and 0, 24 ,48, 72 hours after resuscitation, EVLWI was measured with thermal dilution pulse index continuous cardiac output (PiCCO), and BNP with radioimmunoasaay. Results ① Hemodynamic parameters can be improved at early fluid resuscitation stage in both groups. ② The total amount of fluid[(16 438±1 758) ml], amount of crystalloid fluid[(13 459±425) ml]and crystalloid-colloid ratio (4. 50± 0. 23) of the high crystalloid-colloid ratio group was significantly higher than that of the low crystalloid-colloid ratio group[(13 895±1 783) ml, (6 945± 454) ml, 2. 32± 0. 18, respectively, P＜0. 05or P＜0. 01]at the time point of 72 hours after resuscitation. ③ Compared with low crystalloid-colloid ratio group, PaO2/FiO2 (mm Hg, 1 mm Hg=0. 133 kPa) in high crystalloid-colloid ratio group was lowered significantly at 48 hours and 72 hours after resuscitation (48 hours: 186.51 ±42. 26 vs. 268. 35± 34. 18,72 hours: 172.85 ± 21.50 vs. 263. 95 ± 24.20); but EVLWI, ICP and BNP were increased significantly [EVLWI (ml/kg) 48 hours: 14. 52±1.08 vs. 10. 40±1.16, 72 hours: 14. 92±0. 86 vs. 10. 52±1.02); ICP(cmH2O, 1cm H2O=0.098 kPa) 48 hours: 16.23±1.32 vs. 13.05±1.70, 72 hours: 17.39±1.56 vs.13. 42 ±1. 65 ; BNP (ng/L) 48 hours: 424.29±74.25 vs. 225.32±53.58, 72 hours: 620.49±79.53 vs.288. 28±68. 78, P＜0. 05 or P＜0. 01]. ④ The Pearson correlation analysis showed that: EVLWI with PO2/FiO2 was correlated negatively (r = -0. 71, P＜ 0. 01), but with the BNP, ICP showed positive correlation (r1= 0.63, r2 = 0. 56, both P＜0. 01). Conclusion In order to guide early fluid resuscitation,EVLW, ICP and BNP should be monitored and limited fluid resuscitation strategy with an increasing colloid ratio should be adopted for SAP patients. Key words: Severe acute pancreatitis ;  Fluid resuscitation ;  Crystalloid-colloid ratio ;  Extravascular lung water index ;  Bladder pressure ;  B-type natriuretic peptide ;