Patients and Methods: The study has three parts, in part 1, the safety of subcutaneous injection of sodium bicarbonate was evaluated in 6 rats. In each animal the macroscopic and microscopic effects were evaluated and a safe dilution was determined. In the second part of the study the investigators will evaluated the efficacy of IV diluted SB to detect the proper location of IV catheters. 20 adult patients age 20 to 50 years will be enrolled. Patients all under general anesthesia with standard controlled ventilation via endotracheal tube. The correct placement of IV catheter will be confirmed by easy aspiration of blood from newly placed IV catheter. In each patient a bolus of 50 cc of 0.5 meq/cc SB or volume equivalent of normal saline will be injected in random order. The data collection will include patient's demographics, the presence or absence of an increase in the expired end-tidal carbon dioxide, onset and peak changes of end-tidal carbon dioxide as well as the hemodynamic changes after each injection.