Tao Yuan1,2, Shaoqiang Yang1, Chengteng Lai2, Xin Yu2, Hong Qian1,2, Jia Meng1, Nirong Bao1,2, Jianning Zhao1,2. 1. Department of Orthopedics, Jinling Hospital, The First School of Clinical Medicine, Southern Medical University Guangzhou 510515, China. 2. Department of Orthopedics, Jinling Hospital, Medical School of Nanjing University Nanjing 210002, China.
Abstract
BACKGROUND: Hidden blood loss (HBL) often occurs after joint replacement; however, the mechanism of HBL is not clear. We conducted a prospective study to analyze the correlation between high-level free fatty acids (FFA) and erythrocyte injury, and explore the pathologic mechanism of hidden blood loss (HBL) after total knee arthroplasty (TKA). METHODS: Perioperative blood indexes were tested in 120 patients who underwent unilateral total knee replacement for end-stage knee osteoarthritis. The changes in FFA, reactive oxygen species (ROS), hemoglobin (Hb), and red blood cells (RBC) in the blood samples were detected. The activity of glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD) and hydrogen peroxide (H2O2) levels were measured. Morphologic changes of blood cells were analyzed under a microscope. RESULTS: HBL occurred in all patients after TKA. The Hb and RBC decreased significantly 24 h after surgery (P <0.05), while FFA and ROS concentration were substantially elevated, and heteromorphic red blood cells appeared under the microscope. The hemoglobin content decreased to its lowest level at 48 h after the operation (P<0.01). With the increase of FFA and ROS levels, HBL appeared more obvious (P<0.01). GSH-PX activity, T-SOD activity, and H2O2 levels significantly decreased compared to preoperative tested samples (P<0.01). Microscopically, atypical erythrocytes increased significantly with cellular rupture and lysis identified. CONCLUSIONS: High levels of FFA in blood can induce oxidative stress and damage red blood cells, leading to the occurrence of HBL after surgery. TRIAL REGISTRATION: Chinese Clinical Trials Registry (the trial number: ChiCTR17010681, URL: http://www.chictr.org.cn). IJCEP
BACKGROUND: Hidden blood loss (HBL) often occurs after joint replacement; however, the mechanism of HBL is not clear. We conducted a prospective study to analyze the correlation between high-level free fatty acids (FFA) and erythrocyte injury, and explore the pathologic mechanism of hidden blood loss (HBL) after total knee arthroplasty (TKA). METHODS: Perioperative blood indexes were tested in 120 patients who underwent unilateral total knee replacement for end-stage knee osteoarthritis. The changes in FFA, reactive oxygen species (ROS), hemoglobin (Hb), and red blood cells (RBC) in the blood samples were detected. The activity of glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD) and hydrogen peroxide (H2O2) levels were measured. Morphologic changes of blood cells were analyzed under a microscope. RESULTS: HBL occurred in all patients after TKA. The Hb and RBC decreased significantly 24 h after surgery (P <0.05), while FFA and ROS concentration were substantially elevated, and heteromorphic red blood cells appeared under the microscope. The hemoglobin content decreased to its lowest level at 48 h after the operation (P<0.01). With the increase of FFA and ROS levels, HBL appeared more obvious (P<0.01). GSH-PX activity, T-SOD activity, and H2O2 levels significantly decreased compared to preoperative tested samples (P<0.01). Microscopically, atypical erythrocytes increased significantly with cellular rupture and lysis identified. CONCLUSIONS: High levels of FFA in blood can induce oxidative stress and damage red blood cells, leading to the occurrence of HBL after surgery. TRIAL REGISTRATION: Chinese Clinical Trials Registry (the trial number: ChiCTR17010681, URL: http://www.chictr.org.cn). IJCEP