To explore the use of lactic acid (Lac), central venous oxygen saturation (ScvO₂), and central venous-arterial carbon dioxide partial pressure (Pcv-aCO₂) combined with routine indicators in guiding the fluid management of elderly patients with single-lung ventilation during totally endoscopic radical resection of esophageal cancer.

Forty-one elderly patients with esophageal cancer who underwent laparoscopic radical resection under elective general anesthesia at First Affiliated Hospital of Hebei North University from June 2020 to April 2021 were included. The study subjects were randomly divided into an observation group (21 cases) and a control group (20 cases). Patients of the two groups were given a rapid intravenous infusion of 250 ml of lactated Ringer's solution during the anesthesia induction period, followed by continuous intravenous infusion at a rate of 4-8 ml/(kg·h). The control group was based on mean arterial pressure (MAP) and central venous pressure (CVP), and the observation group was based on ScvO₂, Pcv-aCO₂ and Lac to adjust the infusion volume and the use of vasoactive drugs. The heart rate (HR), MAP, CVP, urine volume, infusion volume, bleeding volume, Lac, ScvO₂, Pcv-aCO₂, and other indicators were recorded and compared between groups at 5 min before induction of anesthesia (T₀), 5 min after tracheal intubation (T₁), before one-lung ventilation (T₂), 1 h of one-lung ventilation (T₃), and the end of one-lung ventilation (T₄).

There were no statistically significant differences in gender or age between the two groups (P＞0.05). MAP and HR at T₁-T₄ were significantly lower than those at T₀ in both groups (P＜0.05), but there were no statistically significant differences among T₁-T₄ (P＞0.05). There were no significant difference in CVP among all time points in the observation group (P＞0.05); in the control group, CVP at T₃ and T₄ were significantly higher than those at T₀-T₂, and the difference between T₃ and T₄ was also statistically significant (P＜0.05). There were no significant difference in SPO₂ at each time point between the two groups (P＞0.05). There was no significant difference between the two groups in MAP at T₀ and T₁ (P＞0.05); MAP at T₂, T₃, and T₄ were significantly higher in the observation group than in the control group (P＜0.05). There was no difference between the two groups in CVP at T₀-T₂ (P＞0.05); CVP at T₃ and T₄ were significantly lower in the observation group than in the control group (P＜0.05). There were no significant differences in intraoperative blood loss, SPO₂, or HR between the two groups (P＞0.05). In the observation group, the urine output was significantly higher, and the total infusion volume and the dose of vasoactive drugs were lower than those of the control group (P＜0.05). In the observation group, there was no significant difference in Lac or ScvO₂ at T₀-T₂, while at T₃ and T₄, Lac were significantly increased (P＜0.05) and ScvO₂ was significantly decreased (P＜0.05). Pcv-aCO₂ had no statistically significant difference at T₀-T₃, but it significantly increased at T₄ (P＜0.05).

Lac, ScvO₂, and Pcv-aCO₂ are correlated with single-lung ventilation in elderly patients with totally endoscopic radical resection of esophageal cancer. The longer the single-lung ventilation time, the more obvious increase of Lac and Pcv-aCO₂ and decrease of ScvO₂.