Evaluation of Serial Lactate Measurements in Carbon Monoxide Poisoning

Aim: Carbon monoxide is a gas that can cause acute poisoning and affect organs such as the brain, heart, and kidneys. The number of studies investigating lactate clearance in patients with CO poisoning is limited. The primary endpoint of our study is to determine whether there is a difference in lactate clearance according to demographic characteristics, hyperbaric oxygen therapy, and clinical outcomes. Material and Methods: Our study was conducted retrospectively. Patients over the age of 18 with carboxyhemoglobin levels >10% and at least two venous blood gas results were included. Demographic characteristics, carboxyhemoglobin and lactate levels in the first and second blood gas analyses, the timing of blood gas sampling, whether or not they received hyperbaric oxygen therapy, and patient outcomes were recorded. Results: A total of 272 patients were included in our study. The mean initial carboxyhemoglobin level was 22.8±8.6 (10.0–60.9). The mean initial lactate level was 2.3±1.8 (0.1–18.0). A decrease in lactate clearance of more than 20% was observed in 37 patients (51.4%) at the 1st hour, 43 patients (66.2%) at the 2nd hour, 75 patients (77.3%) at the 3rd hour, and 29 patients (76.3%) at the 4th hour. When grouped according to the timing of blood gas sampling, no significant difference was found between the first and second CO and lactate levels. A decrease in lactate clearance of more than 20% was not statistically significant in terms of age, gender, carboxyhemoglobin levels, and patient outcomes. Conclusion: No statistically significant association was found between patient outcomes and lactate clearance.