Objective: To investigate the effects of continuous goal-directed analgesia on fluid resuscitation during shock stage in patients with massive burns, providing a basis for rational optimization of analgesia protocols in patients with burn shock. Methods: A retrospective case series study was conducted. One hundred and thirty-six patients with massive burns who met the inclusion criteria were admitted to Zhengzhou First People's Hospital from January 2015 to December 2020, and the patients were divided into continuous analgesia (CA) group (68 cases,with average age of 44 years old) and intermittent analgesia (IA) group (68 cases,with average age of 45 years old) according to whether sufentanil injection was continuously used for intravenous analgesia during the shock stage. The patients in the 2 groups were predominantly male. Before and at 72 h of treatment, the severity of disease and trauma pain of patients in the 2 groups were scored by the acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) and the visual analogue scale (VAS). Hematocrit, heart rate, mean arterial pressure (MAP), central venous pressure (CVP), oxygen saturation in central venous blood (ScvO2), rehydration coefficient, blood lactate value, hourly urine output, and the adverse reactions such as hypotension, nausea, vomiting, dizziness, skeletal muscle tonicity, respiratory depression, bradycardia, pruritus, and drug addiction of patients in the 2 groups during the treatment were recorded at the 1st, 2nd, and 3rd 24 h post-injury. Data were statistically analyzed with analysis of variance for repeated measurement, paired or independent sample t test, Bonferroni correction,chi-square test and Mann-Whitney U test. Results: Before treatment, APACHE Ⅱ and VAS scores of patients in the 2 groups were close (with t values of -0.67 and 0.32, respectively, P>0.05); At 72 h of treatment, APACHE Ⅱ and VAS scores of patients in CA group were 8.5±2.2 and 2.5±1.6, both of which were significantly lower than (15.2±3.0) and (7.9±2.0) of patients in IA group, respectively (with t values of -14.94 and -17.46, respectively, P<0.01). Compared with the pre-treatment period, the APACHE Ⅱ and VAS scores of patients in IA group decreased significantly at 72 h of treatment (with t values of 11.35 and 30.59, respectively, P<0.01); the changes in APACHE Ⅱ and VAS scores of patients at 72 h of treatment in comparison with those of patients before treatment in CA group were all similar to those of patients in IA group (with t values of 4.00 and 4.82, respectively, P<0.01). Compared with those of patients in IA group, there were no significant changes in CVP, hematocrit, heart rate, ScvO2, and MAP of patients in CA group at all three 24 h post-injury (with t values of <0.01, 0.12, 2.10, 1.55, 0.03; 0.13, 0.22, <0.01, 0.17, 0.49; 0.63, 0.06, 0.04, 2.79, and 2.33, respectively, P>0.05). Compared with those of patients in IA group at the 1st 24 h post-injury, CVP, ScvO2 and MAP of patients were significantly higher at the 2nd and 3rd 24 h post-injury (with t values of -10.10, -9.31, -8.89; -10.81, -4.65, and -9.43, respectively, P<0.01), and the heart rate of patients was significantly lower at the 2nd and 3rd 24 h post-injury (with t values of 7.53 and 7.78, respectively, P<0.01), and the hematocrit of patients decreased significantly only at the 3rd 24 h post-injury (t=15.55, P<0.01); the changes of CVP, ScvO2, MAP and heart rate of patients at the 2nd and the 3rd 24 h post-injury, and HCT of patients at the 3rd 24 h post-injury, in comparison with those of patients at the 1st 24 h post-injury in CA group were similar to those of patients in IA group (with t values of -12.25, -10.24, -8.99, 9.42, -8.83, -7.53, -11.57, 10.44, and 12.91, respectively, P<0.01). Compared with those of patients in IA group, the rehydration coefficient of patients in CA group was significantly higher only at the 3rd 24 h post-injury (t=5.60, P<0.05), blood lactate value of patients in CA group was significantly lower at the 1st and 2nd 24 h post-injury (with t values of 4.32 and 14.52, respectively, P<0.05 or P<0.01), the hourly urine output of patients in CA group increased significantly at the 1st, 2nd, and 3rd 24 h post-injury (with t values of 24.65, 13.12, and 5.63, respectively, P<0.05 or P<0.01). Compared with the those of patients at the 1st 24 h post-injury, the rehydration coefficient of patients in IA group decreased significantly at the 2nd and the 3rd 24 h post-injury (with t values of 33.98 and 36.91, respectively, P<0.01), the blood lactate values of patients in IA group decreased significantly at the 2nd and the 3rd 24 h post-injury (with t values of 8.20 and 11.68, respectively, P<0.01), and the hourly urine output of patients in IA group was significantly increased at the 2nd and the 3rd 24 h post-injury (with t values of -3.52 and -5.92, respectively, P<0.01); the changes of rehydration coefficients and blood lactate values of patients at the 2nd and the 3rd 24 h post-injury in comparison with those of patients at the 1st 24 h post-injury in CA group were similar to those of patients in IA group (with t values of 35.64, 33.64, 9.86, and 12.56, respectively, P<0.01), but hourly urine output of patients in CA group increased significantly only at the 3rd 24 h compared with that of patients at the 1st 24 h post-injury (t=-3.07, P<0.01). Adverse reactions such as hypotension, nausea, vomiting, dizziness, bradycardia, and pruritus occurred rarely in patients of the 2 groups, and none of the patients had skeletal muscle tonicity, respiratory depression, or drug addiction. The incidence of adverse reactions of patients in CA group was similar to that in IA group (χ2=0.08, P>0.05). Conclusions: Continuous goal-directed analgesia can effectively relieve pain and improve vital signs of patients with large burns. Meanwhile it has little impact on volume load, which can assist in correcting ischemia and hypoxia during the shock period and help patients get through the shock period smoothly.