Extravasation is an unintentional injection or leakage of fluids in the perivascular or subcutaneous space. Extravasation can be associated with tissue injury with various level of severity and long term consequences. Currently the confirmation of intravenous location of the Intravenous (IV) catheter requires close observation of the insertion site with sufficient infiltration in the perivascular area to allow detection of swelling, discoloration and discomfort. Under Anesthesia direct observation is frequently prohibited. IV sodium bicarbonate (SB) is used frequently to treat different metabolic conditions and is known to cause a temporary elevation of exhaled carbon dioxide. This study aim is to evaluate the safety and efficacy of intravenous SB as a detector of intravenous placement of an IV line in anesthetized patients.

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.

Inclusion Criteria:

• Healthy (American Society of Anesthesiologists [ASA] I or II) volunteers

Exclusion Criteria:

• respiratory disease
• active smoking
• cardiovascular disease
• renal disease