Intraoperative volume restriction in esophageal cancer surgery: an exploratory randomized clinical trial

Aim

To investigate whether the fluid volume administered during esophageal cancer surgery affects pulmonary gas exchange and tissue perfusion.

Methods

An exploratory single-center randomized clinical trial was performed. Patients with esophageal cancer who underwent Lewis-Tanner procedure between June 2011 and August 2012 at the Department of Thoracic surgery “Jordanovac”, Zagreb were analyzed. Patients were randomized (1:1) to receive a restrictive volume of intraoperative fluid (≤8 mL/kg/h) or a liberal volume (>8 mL/kg/h). Changes in oxygen partial pressure (Pao₂), inspired oxygen fraction (FiO₂), creatinine, and lactate were measured during and after surgery.

Results

Overall 16 patients were randomized and they all were analyzed (restrictive group n = 8, liberal group n = 8). The baseline value Pao₂/FiO₂ ratio (restrictive) was 345.01 ± 35.31 and the value six hours after extubation was 315.51 ± 32.91; the baseline Pao₂/FiO₂ ratio (liberal) was 330.11 ± 34.71 and the value six hours after extubation was 307.11 ± 30.31. The baseline creatinine value (restrictive) was 91.91 ± 12.67 and the value six hours after extubation was 100.88 ± 18.33; the baseline creatinine value (liberal) was 90.88 ± 14.99 and the value six hours after extubation was 93.51 ± 16.37. The baseline lactate value (restrictive) was 3.93 ± 1.33 and the value six hours after extubation was 2.69 ± 0.91. The baseline lactate value (liberal) was 3.26 ± 1.25 and the value six hours after extubation was 2.40 ± 1.08. The two groups showed no significant differences in Pao₂/FiO₂ ratio (P = 0.410), creatinine (P = 0.410), or lactate (P = 0.574).

Conclusions

Restriction of intraoperative applied volume does not significantly affect pulmonary exchange function or tissue perfusion in patients undergoing surgical treatment for esophageal cancer.Trial registration number: Clinical Trials {"type":"clinical-trial","attrs":{"text":"NCT 02033213","term_id":"NCT02033213"}}NCT 02033213.Pulmonary complications remain a primary cause of morbidity after esophageal cancer surgery. Complications range from atelectasis and pneumonia to acute lung injury and acute respiratory distress syndrome; the risk of these complications is determined largely by preoperative pulmonary status and surgical approach (1). Another factor that can influence the risk of postoperative respiratory complications is the volume of fluid administered intraoperatively (2,3). Such fluid administration is a routine procedure during lung and esophageal surgery (4).The optimal type and volume of fluid are controversial issues and have not been standardized in international guidelines (5). Several studies suggest that restrictive intraoperative fluid resuscitation during open abdominal surgeries is superior to an aggressive or “liberal” fluid protocol, because it is associated with fewer postoperative complications and shorter discharge time (6-8). On the other hand, restrictive fluid management can lead to hypovolemia and impaired tissue perfusion, which can cause organ dysfunction, particularly postoperative acute kidney injury (9).In esophageal surgery, fluid management is a special concern because one-lung ventilation (OLV), which is an integral part of anesthesia, can cause postoperative pulmonary edema (10-13). When conventional ventilation is reestablished after surgery, reexpansion of the deflated lung can induce oxidative stress that leads to edema (12-15). In this way, OLV may aggravate the postoperative effects of perioperative pulmonary fluid overload (16). The aim of this exploratory trial was to compare the effects of restrictive and liberal fluid resuscitation protocol on pulmonary gas exchange and tissue perfusion.