Nursing student here! If you have known issues with your kidneys, this could be an expected result. Your kidneys secrete HCO3 which is a base. It helps maintain the acid-base balance in your body. In this result, the pCO2 is more basic to compensate for the fact that the kidneys are not secreting enough HCO3 (bicarbonate). If you don’t have kidney problems, I’m not by any means telling you that you do. I’m just saying that for whatever reason, your bicarbonate was low, so your PCO2 being more basic (less than 35) is a compensatory mechanism. Honestly, I’d think a PCO2 on the higher side would be a problem for surgery. That means you’d have a problem with ventilation (45+ is more acidic) and were retaining CO2 which would be a problem for anesthesia. I don’t think you have anything to worry about!