Sepsis occurs frequently among critically ill patients hospitalized in intensive care units (ICUs). A key goal in treating patients suffering from septic shock is to normalize cardiac function while maintaining optimal fluid balance and tissue oxygenation levels. Intravenous fluid resuscitation and management is often critical to survival, but can also lead to fluid overload and potentially fatal downstream consequences. Currently there is a lack of adequate tools with which to monitor patient responses to fluid infusion, particularly those that can safely and accurately measure cardiac output or detect the onset of fluid overload. In response to this need we have developed the OmniSense catheter. Its innovative design combines fast pressure sensing functionality within the structure of a standard urinary drainage catheter. The sensitivity and bandwidth of our pressure measurement enables the monitoring of changes in cardiac output (from the relative amplitude of cardiovascular pressure waves transmitting into the bladder) and intra-abdominal pressure, both of which can be critical pieces of information for clinicians making treatment decisions during sepsis management. Use of the OmniSense catheter has clear advantages over other more invasive methods to measure cardiac output and detect fluid overload. Currently available tools to measure cardiac output (i.e. the Swan- Ganz catheter or Long Time Interval analysis based on arterial catheter measurements) have been shown to incur unacceptable infection risk for the patient and significantly increase the burden on nursing staff to administer and maintain. Moreover, methods to detect fluid overload often rely on observations during physical exam which are intermittent, subjective, and non-quantitative. The OmniSense device has the potential to directly track changes in cardiac output and detect fluid overload continuously, automatically, and quantitatively without any additional invasiveness or further burden on nursing staff. Our preliminary data support the feasibility of measuring relative cardiac output using the OmniSense and we have previously demonstrated the capacity of the device to provide clinically relevant readings of changes in intra-abdominal pressure. Here we propose to use a porcine model to test the capacity of the OmniSense to deliver accurate readings of changes in cardiac output in response to pharmacological manipulations of cardiac function. In addition we will experimentally induce fluid overload and test the ability of the OmniSense to detect the development of this condition early based on measurements of intra-abdominal pressure. This work is a crucial first step to lay the groundwork for future clinical studies with he ultimate goal of improving outcomes for critically ill patients suffering from septic shock and other forms of hemodynamic insult.
Sepsis occurs in approximately one-third of patients in the Intensive Care Unit, where it is a leading cause of morbidity and mortality. Among patients suffering from septic shock or other forms of hemodynamic insult, fluid resuscitation treatment is critical to normalizing cardiac output and thus survival, but clinicians are lacking good tools for assessing the effects of their ongoing management. The OmniSense device is designed to aid clinicians in hemodynamic optimization by providing accurate real-time measurements of changes in cardiac output and intra-abdominal pressure, without introducing any additional risk to the patient.
| Kramer, George C; Luxon, Evan; Wolf, Jordan et al. (2017) Inaccuracy of Urine Output Measurements due to Urinary Retention in Catheterized Patients in the Burn ICU. J Burn Care Res 38:e409-e417 |
