Objective  To investigate the effects of different postures in prone position on intraoperative blood circulation in patients undergoing thoracolumbar surgery and its impact in preventing pressure injury (PI).

Methods  A total of 87 patients who underwent posterior thoracolumbar interbody fusion implant from April 2020 to February 2021 were selected and randomly divided into observation group (42 cases) and control group (45 cases). Deep vein thrombosis (DVT) and PI were compared between the two groups. Lower extremity venous pressure (LEVP), heart rate and mean arterial pressure at supine position before prone position (T₀), immediately after prone position stabilization (T₁), 0.5h after operation (T₂), 1 hafter operation (T₃), 1.5h after operation (T₄) and 2h after operation (T₅), at the end of surgery (T₆) and immediately after stability of returning the supine position following the operation (T₇) were respectively recorded.

Results  Compared with T₀, values of LEVP at time points from T₁to T₆ in the observation group were higher (P < 0.05). Compared with T₀, values of LEVP at time points from T₁ to T₇ in the control group were higher (P < 0.05). The difference values of LEVP between T₁ and T₀ as well as between T₇ and T₀ (ΔLEVP) were statistically significant between the two groups (P < 0.05). In the observation group, DVT occurred in 1 case and did not occur in 41 cases. In the control group, 7 cases of DVT occurred and 38 cases had no DVT. There was statistical significance in the incidence of lower extremity DVT 3d after operation between two groups (P < 0.05). The incidence rates of PI in the left and right iliac parts of the observation group were lower than those of the control group, and the differences were statistically significant (P < 0.05). The severity of PI in both groups was stage Ⅰ. There were no significant differences in the incidence rates of PI in the head and face, anterior chest and the knees in two groups (P>0.05). There was no significant difference in heart rate, mean arterial pressure, blood loss and operation time between two groups in prone position at different time points (P>0.05).

Conclusion  Lower angle placement of lower extremity in prone position for thoracolumbar surgery patients can effectively reduce the effect of operation on venous blood reflux in lower limbs compared with the traditional angle, which is conducive to the prevention of DVT. Dispersing the area of support points in the prone position reduces the pressure on the iliac bone and significantly reduces the occurrence of PI.