Abstract: Objective To explore the guiding significance of pulse contour cardiac output (PiCCO) monitoring technology in the treatment of fluid replacement during shock stage of extensive burn in clinic. Methods Sixty-five patients with extensive burn hospitalized in our unit from January 2014 to December 2018, conforming to the inclusion criteria, were recruited to conduct a prospective controlled research. According to the order of admission, 35 odd-numbered patients and 30 even-numbered patients were enrolled in routine rehydration group (25 males and 10 females) and PiCCO monitoring rehydration group (21 males and 9 females) respectively, with the age of (48±9) and (44±8) years respectively. All patients of the two groups were rehydrated according to the rehydration formula of the Third Military Medical University during shock stage. The rehydration speed was adjusted in routine rehydration group according to the general indexes of shock such as central venous pressure, mean arterial pressure, heart rate, respiratory rate, urine volume, and clinical symptoms of patients. PiCCO monitoring was performed in patients of PiCCO monitoring rehydration group, and the global end-diastolic volume index combined with the other relevant indicators of PiCCO were used to guide rehydration on the basis of the monitoring indicators of routine rehydration group. The heart rates and positive fluid balance volumes at post injury hour (PIH) 8, 16, 24, 32, 40, 48, 56, 64, and 72, the diuretic dosage at PIH 48 and 72, the total fluid replacement volumes, urine volumes, blood lactic acid, platelet count, and hematocrit at PIH 24, 48, and 72, the length of intensive care unit (ICU) stay, and the incidence of complications and death within 28 days after injury were compared between patients in the two groups. Data were processed with analysis of variance for repeated measurement, t test, Bonferroni correction, Mann-Whitney U test, chi-square test, and Fisher′s exact probability test. Results The heart rates of patients in the two groups were similar at PIH 8, 16, 24, 32, 40, 48, and 56 (t=0.775, 1.388, 2.511, 2.203, 1.654, 2.303, 1.808, P>0.05), and the heart rates of patients in PiCCO monitoring rehydration group at PIH 64 and 72 were obviously lower than those of routine rehydration group (t=3.229, 3.357, P<0.05 or P<0.01). The positive fluid balance volumes of patients in the two groups were similar at PIH 8, 16, 40, and 56 (t=0.768, 1.670, 2.134, 2.791, P>0.05), and the positive fluid balance volumes of patients in PiCCO monitoring rehydration group at PIH 24, 32, 48, 64, and 72 were obviously less than those of routine rehydration group (t=3.364, 4.047, 2.930, 2.950, 2.976, P<0.05 or P<0.01). The amount of diuretics used by patients in the two groups was similar at PIH 48 and 72 (Z=-0.697, -1.239, P>0.05). The total fluid replacement volumes of patients in PiCCO monitoring rehydration group at PIH 24, 48, and 72 were (13 864±4 241), (9 532±2 272), and (8 480±2 180) mL, respectively, obviously more than those in routine rehydration group [(10 388±2 445), (8 095±1 720), and (7 059±1 297) mL, respectively, t=-3.970, -2.848, -3.137, P<0.05 or P<0.01]. The urine volumes of patients in the two groups at PIH 24 were close (t=-1.027, P>0.05). The urine volumes of patients in PiCCO monitoring rehydration group at PIH 48 and 72 were (3 051±702) and (3 202±624) mL respectively, obviously more than those in routine rehydration group [(2 401±588) and (2 582±624) mL respectively, t=-4.062, -4.001, P<0.01]. The levels of blood lactate acid of patients in PiCCO monitoring rehydration group at PIH 24, 48, and 72 were obviously lower than those in routine rehydration group (t=4.758, 6.101, 3.938, P<0.01). At PIH 24 and 48, the values of the platelet count of patients in PiCCO monitoring rehydration group were obviously higher than those in routine rehydration group (t=-2.853, -2.499, P<0.05), and the values of hematocrit of patients in PiCCO monitoring rehydration group were obviously lower than those in routine rehydration group (t=2.698, 4.167, P<0.05 or P<0.01). Both the platelet count and hematocrit of patients in the two groups were similar at PIH 72 (t=-1.363, 0.476, P>0.05). The length of ICU stay of patients in PiCCO monitoring rehydration group was obviously shorter than that of routine rehydration group (t=2.184, P<0.05). Within 28 days after injury, the incidence of complications of patients in routine rehydration group was obviously higher than that in PiCCO monitoring rehydration group (P<0.05), while the mortality rate of patients in routine rehydration group was similar to that in PiCCO monitoring rehydration group (P>0.05). Conclusions The application of PiCCO monitoring technology in monitoring fluid replacement in patients with extensive burn can quickly correct shock, reduce the occurrence of organ complications caused by improper fluid replacement, and shorten the length of ICU stay, which is of great significance in guiding the treatment of burn shock.