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

Prospective Non-Interventional Study Evaluating Non-invasive Measurements of Pulmonary Blood Flow, Functional Residual Capacity, Shunt Fraction Index and Airway Dead Space Measured With the VQm PHM™ to Clinical Gold Standards

This is a prospective, observational study to assess agreement of pulmonary health parameters measured by a new non-invasive physiologic monitor, the VQm pulmonary health monitor (PHM)™ with clinical gold standards.

The specific aim of this study is to evaluate the intermittent non-invasive measurements of pulmonary function: pulmonary blood flow (PBF), functional residual capacity (FRC), shunt fraction index (Qsi) and airway dead space measured by the VQm PHM™ compared to known clinical standards. PBF will be compared to continuous and intermittent bolus thermodilution cardiac output as measured through a Swan-Ganz catheter. FRC will be compared to an FRC measurement provided by a standard nitrogen washout method. Qsi will be compared to shunt fraction calculated through mixed venous and arterial blood gas values (VBGs/ABGs). Airway dead space will be compared to an airway dead space measurement provided by a ventilator.

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