Evaluation of Novel Cardio-Pulmonary Physiological Monitor, the VQm PHM™, for Acute Care Medicine

Inclusion Criteria: * Age greater than 18 years * Scheduled for an elective surgical procedure with an anticipated duration of more than 2 hours requiring general anesthesia without the use of inhalation anesthetics * Surgical procedure that requires pressure-controlled positive pressure ventilation using an endotracheal tube * Surgical procedure that requires the use of intra-arterial pressure monitoring and/or a Swan-Ganz catheter for the monitoring of continuous cardiac output Exclusion Criteria: * Patients who require ventilation tidal volumes less than 250cc * Age less than 18 years * Pregnancy * Prisoners * Surgical procedure which requires carbon dioxide (CO2) insufflation * Unable to tolerate a transient increase in inhaled CO2 * Unable to tolerate a transient increase in inhaled nitrous oxide (N2O) or use of N2O is contraindicated * Patients who require a high fraction of inspired oxygen (FiO2) (\>70%) to maintain a hemoglobin saturation (SpO2\>98%) Women, minorities or non-English speaking subjects will not be excluded