Abstract: Objective To investigate the effects of micro-tab diuretics on the homeostasis, postoperative tissue edema and hypoxemia in patients undergoing shoulder arthroscopy for rotator cuff injury under general anesthesia. 
Methods A total of 78 patients undergoing shoulder arthroscopy for rotator cuff injury under general anesthesia were selected, and randomly divided into the control group (n=39)and an observation group (n=39). Thirty minutes before the end of the operation, the observation group was given furosemide 2 mg intravenously and the control group was given an equal amount of saline intravenously. The incidence of hypoxemia, intraoperative condition (intraoperative infusion volume, intraoperative lavage volume, intraoperative sufentanil dosage, intraoperative propofol dosage, intraoperative vasoactive drug dosage, and duration of operation), blood gas analysis results ［arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), pH value］ at the time of tracheal intubation, at the end of operation and 30 min after operation, electrolytes(calcium ions, potassium ions, sodium ions, chloride ions), blood glucose concentration, relative blood volume (RBV), and tissue edema at the end of operation, and at 30 min, 60 min, and 8 h after surgery were compared between two groups. 
Results There was no statistically significant difference in intraoperative infusion volume, intraoperative lavage volume, intraoperative sufentanil dosage, intraoperative propofol dosage, and duration of operation between two groups (P＞0.05). PaO2, PaCO2, and pH value did not change with time, and there was no significant difference in interactions between groups, time points and time points between groups (P＞0.05). Calcium ion, potassium ion, sodium ion, chloride ion, RBV, and blood glucose concentration did not change with time, and there was no significant difference in interactions between groups, time points and time points between groups (P＞0.05). The tissue thickness from the surface of the second rib to the skin on the healthy side of the two groups did not change with time, and there was no significant difference in interactions between groups, time points and time points between groups (P＞0.05). The tissue thickness from the surface of the second rib to the skin on the affected side of the midclavicular line showed a trend of first increasing and then decreasing over time, and there was no significant difference in interactions between groups, time points and time points between groups (P＜0.05). The tissue thickness of the surface of the second rib to the skin on the affected side of the midclavicular line was greater than that of the healthy side during the same period in the two groups at the end of operation, and at 30 min and 60 min after surgery, and the tissue thickness of the surface of the second rib to the skin on the affected side of the midclavicular line was greater than that of the healthy side during the same period in the observation group at 8 h after surgery (P＜0.05). 
Conclusion Microfurosemide can prevent hypoxemia and reduce postoperative tissue edema in patients undergoing shoulder arthroscopy, and is beneficial for maintaining homeostasis. 

Key words: shoulder injuries, furosemide, tissue edema