Study on the consistency and correlation of different methods for measuring energy consumption in patients with severe acute pancreatitis / 中华消化杂志

ABSTRACT

Objective:To analyze the consistency and correlation of indirect calorimetry (IC) and Harris-Benedict estimation method (H-B) in measuring energy consumption in patients with severe acute pancreatitis (SAP), as well as the characteristics of energy metabolism at resting state of SAP patients with different etiologies, and so as to guide the formulation of clinical energy nutrition support program.Methods:From February 1 to December 31, 2019, 61 SAP patients admitted into the intensive care unit of the First Affiliated Hospital of Nanchang University were enrolled. Collected relevant data of patients, such as the etiology of SAP, whether mechanical ventilation was needed, as well as the metabolic status. All SAP patients accepted IC test on the first day after admission to intensive care unit. According to the energy consumption measured by IC (hereinafter referred to as IC value) and the energy consumption measured by H-B (hereinafter referred to as H-B value), SAP patients were determined to be in high, normal or low metabolic state. Bland-Altman method and Pearson linear regression were used to analyze the consistency and correlation of the two methods in measuring energy consumption, and the linear equation was fitted. Paired t test was used for statistical analysis. Results:Among the 61 SAP patients, 13 cases were biliary SAP, 30 cases were hyperlipidemic SAP, 6 cases were alcoholic SAP, and 12 cases were SAP of other causes or unknown causes. Nineteen cases needed mechanical ventilation and 42 cases did not need mechanical ventilation. There were 70.5% (43/61) of SAP patients in high metabolic state, 13.1%(8/61) of SAP patients in normal metabolic state, and 16.4% (10/61) of SAP patients in low metabolic state. The IC value in 61 SAP patients was higher than H-B value((8 604.7±367.8) kJ/d vs. (6 491.2±133.7) kJ/d), and the difference was statistically significant ( t=5.95, P<0.001). The IC value in patients with hyperlipidemic, alcoholic and biliary SAP was (8 815.2±537.9), (7 631.2±890.5), and (8 108.0±933.1) kJ/d, respectively, and the H-B value was (6 869.6±204.5), (5 916.8±153.7), and (5 974.2±200.9) kJ/d, respectively. The IC value in patients with biliary or hyperlipidemic SAP were higher than H-B value, and the differences were statistically significant( t=2.29 and 3.38, both P<0.05). The IC value and H-B value in SAP patients with mechanical ventilation and without mechanical ventilation were (10 485.0±741.1) and (6 462.6±222.8) kJ/d, (6 595.1±364.7) and (6 503.2±166.7) kJ/d, respectively. The IC value in SAP patients with mechanical ventilation was higher than H-B value and the IC value in SAP patients without mechanical ventilation, and the differences were statistically significant ( t=4.71 and 5.20, both P<0.001). The consistency analyzed by Bland-Altman method showed that the two methods had obvious biases, and the average bias value was 92.2 kJ/d. The result of Pearson linear regression analysis indicated that there was a linear relationship between two methods ( r=0.44, P<0.001). The linear equation fitted by the univariate regression was Y=1.240 6 X+ 154.42, in which X was the H-B value and Y was the IC value. Conclusions:SAP patients are mostly in a hypermetabolic state in the early stages of the disease. The IC value is higher than H-B value, and it is recommended to use IC to measure energy consumption in SAP patients.