Evaluation of tissue oxygenation in upper extremities in nephrectomy surgeries

Aim: One of the preferred surgical treatment methods in kidney tumors is laparoscopic nephrectomy. Because of the most common complication of the surgery is bleeding, the lateral decubitus position causes hypotension due to lowering the preload, laparoscopy increase in mean arterial pressure and decrease in cardiac output due to pneumoperitoneum, and decrease in cardiac contractility due to the effect of hypercarbia, due to hemodynamic changes, invasive artery monitoring, which is one of the invasive monitoring, is generally used. We wanted to evaluate the correlation of the Inspectra StO2 Spotcheck (Hutchinson Technology Inc, Minnesota, USA) device, which shows tissue oxygenation from the thenar area of the hand using the NIRS technique, which is a non-invasive technique with arterial monitoring due to complications of invasive interventions such as embolism, thrombus, dissection, and ischemia in the extremity. Patients and Methods: After obtaining the permission of the Local Ethics Committee, adult patients scheduled for elective nephrectomy surgery by the Urology Department were included in the study. StO2 values and simultaneous blood gas parameters before anesthesia application, 5 minutes after intubation, 15th minute, 30th minute, 60th minute after turning to the lateral decubitus position, 120th minute if the operation is prolonged, and before extubation after the patient is placed in the supine position was measured. Results: A total of 41 patients were included in the study. It was observed that StO2 measurements decreased from the 60th minute of the lateral decubitus position and lactate increased, but it was not statistically significant. In addition, it was not found clinically significant since the lactate value never exceeded 2 mmol/l. No significant correlation was found between StO2 and PaO2 measurements, but a significant correlation was found between StO2 upper measurements and lactate (p = 0.002). The patients were divided into groups according to their body mass index, the American society of anesthesiologists preoperatif risk assessment score, and the presence or absence of preoperative anemia. StO2 values were found to be lower in patients with a body mass index> 30 in the supine position before anesthesia. Lactate values in ASA 3 patients were higher in all measurements than those with ASA <3. In addition, ASA3 patients received more vasopressor and blood product replacement. StO2 and THI measurements were lower in patients with preoperative anemia than those without anemia. Those with preoperative anemia received more blood product replacement. viii Conclusions: In this study, nephrectomy operations performed by laparoscopic method in lateral decubitus position were examined. Our results suggest that StO2 monitoring can show the lactate level. In our study, it is concluded that it would be more appropriate to perform the measurement from the upper hand. However, the statistical power of this inference is weak due to the limited number of patients who develop bleeding and similar complications. On the other hand, further studies are needed to reveal medical conditions that cause a measurement difference in the upper and lower hand and whether this difference can provide an early warning in critical or major surgery patients. 2021, 76 Keywords: Nephrectomy, Lateral decubitus position, Tissue oxygenation, StO2, Laparoscopy, General Anesthesia