Hemodynamic Monitoring: Hospital Information Technology and Intensive Care: An Inseparable Duet

Intensivists increasingly use the integration of data and devices in efforts to improve patient care.
By: 
J. Steven Hata, MD, director, Division of Critical Care, Department of Anesthesia and Kristy Walker

 

May 22, 2006

Intensive care units are highly dependent on the efficient transfer of physiological data to multiple healthcare providers. In the delivery of healthcare in 2006 there exists a strong rationale for a tight relationship between critical care and information technology (Celi, Hassan, Marquardt, Breslow, & Rosenfeld, 2001).
First and foremost is patient safety. Our patient population is aging. Major events in this patient group (e.g., cardio-pulmonary arrest) can be predicted by abnormalities in patients' vital signs (Fieselmann, Hendryx, Helms, & Wakefield). Furthermore, severity of illness within intensive care remains high. Demand exceeds supply of both ICU healthcare providers and critical care beds. To complicate the matter further, there is increasing pressure to provide high-level intensive care in an era of increasing cost control.
Hospital Information Technology appears to offer a means to address these challenges. By increasing accessibility to information about our patients, our diverse, highly trained intensive care workforce may achieve advantages, addressing the challenges of supply and demand. Donabedian, in his sentinel work, emphasized the development of “structure, the implementation of effective care processes, and...adaptive quality assessments” in order to achieve progressive quality in healthcare (Donabedian, 1988).
Within critical care, the reality of connecting physiological monitors, essential life support devices such as mechanical ventilators and high-intensity-care units throughout a hospital are increasingly achievable. The benefits of this structure — enhancing critical information transfer — can only be obtained through deliberate planning. We must develop improved strategies to use the increased quantity of clinical data generated by our medical monitors and devices.
Intensivists, surgeons, critical care nurses and other healthcare providers use biomedical information from the ICU monitors to reverse abnormal physiology. Physiological information will become increasingly available to ICU physicians, both within and outside of the hospital. Early evidence supports using ICU monitoring data within a scope of clinical care, favorably improving hospital outcomes (Breslow et al.).

First-Hand Experience
Importantly, at the University of Iowa Hospitals and Clinics (UIHC), we are in the midst of a renaissance of IT capabilities within our intensive care practice. As a rural, tertiary level hospital, we do not have the capacity to have an intensivist at the patient's bedside 24/7 in all of our six ICUs. As a result of the efforts of our hospital IT department, intensivists can now “see” the majority of physiological vital signs (e.g., temperature, pulse, pulse oximetry, capnometry, arterial pressure, ventilator data and ICU alarms) on personal computers, both inside and outside of the hospital around the clock.
This practice has helped to extend limited intensivist resources. Remotely, the intensivists can read the medical record, review critical labs, and inspect relevant radiology. In the upcoming months, our intensivists will be able to confirm that appropriate processes of ICU care have been completed on a timely basis via the Internet (for example, hyperglycemia control).
Have these enhancements decreased nighttime journeys to the University Hospital for on-call intensivists? No — at least not yet. Our intensivist colleagues continue to strongly support the bedside evaluation of care that has developed over the years of traditional medical practice.
The new technology has, however, limited some worry and the number of phone calls by allowing the intensivist the option to monitor ICU patients remotely throughout the day and night. Some have reported early recognition and treatment of developing issues of patient care — this is encouraging but anecdotal. There is a significant need for an innovative, randomized, controlled trial that proves that this new high-level of connectivity clearly improves clinical outcomes in multiple clinical settings.
But challenges remain.
The cornerstones to building increased connectivity of ICU data — the “eICU” — must include ensuring communication of essential ICU devices necessary for clinical decision-making. Clinicians need to develop an understanding of the predictive value of ICU electronic data; we need to learn what the key eICU data elements are that can be used effectively to improve patient care.

Quality, Not Just Quantity
In the integration of data and devices it is not enough to collect the data and put it on a legal document. It needs to be presented in a way that enables accurate interpretation, evaluation and appropriate monitoring. Today's tools can enable practitioners to be data rich and, at times, information poor.
In prepping for the implementation of our critical care system, the proposed legal chart document reflected data points for one patient's 24-hour experience in the ICU, totaling 14 pages. Rich in data points, the proposed document would have failed to serve even a trial lawyer well.
Our challenge is to be both savvy and simple in our solutions, summarizing presentations based on the patient's condition so as to enable quick evaluation and a tuned sensitivity to changes in the patient's status.
Key to the success is an intelligent dashboard that, within seconds of review, enables the physician to assess patient acuity across the unit and triage their attention to those of priority need. Intuitively, these tools must guide the care team in best practices, as well as adequately collect appropriate data to support continual background evaluation.
The prudent consumer of each hospital device purchase will carefully consider its capabilities in connectivity within the overall scope of the virtual IT environment.

Speaking the Same Language
There is a strong need for standardization of languages to allow for the integration of biomedical devices. Automation forces collaboration between clinical entities. It forces the "apple to oranges" ambiguities that are tolerated in a paper world to be resolved. Not only do standard processes and languages serve to get the disparate entities on the same page, they serve back-end outcome evaluation and process improvement initiatives.
Finally, fundamental to improving healthcare is the continuous measurement of outcomes (Donabedian, 1988). Adapting and improving clinical practice requires ongoing measurements to identify both successful and challenged processes of care. This information, in turn, must be integrated into an institutional structure to refine clinical practices.
In 2001 the Institute of Medicine in Crossing the Quality Chasm emphasized the importance of building organizational supports for improving the delivery of healthcare (America, 2001). The integration of IT and ICU practice can be an important bridge, if deliberately planned and thoughtfully constructed. Through careful assembly of data, complete with appropriately targeted alerts and best-practice guidelines, intensivists will be better positioned to deliver high-level intensive care to our high-risk patients.

References:
Committee on Quality Care in America, C. o. Q. H. C. i. (2001). Crossing the quality chasm: a new health system for the 21st century. Washington, DC: National Academic Press.
Breslow, M. J., Rosenfeld, B. A., Doerfler, M., Burke, G., Yates, G., Stone, D. J., et al. Effect of a multiple-site intensive care unit telemedicine program on clinical and economic outcomes: an alternative paradigm for intensivist staffing. Crit Care Med. 2004 Jan;32(1):31-8.
Celi, L. A., Hassan, E., Marquardt, C., Breslow, M., & Rosenfeld, B. (2001). The eICU: it's not just telemedicine. Crit Care Med, 29 (* Suppl), N183-189.
Donabedian, A. (1988). The quality of care: how can it be assessed? Jama, 260, 1743.
Fieselmann, J. F., Hendryx, M. S., Helms, C. M., & Wakefield, D. S. Respiratory rate predicts cardiopulmonary arrest for internal medicine inpatients. J Gen Intern Med. 1993 Jul;8(7):354-60.

7th International Consensus Conference in Intensive Care Medicine
Hemodynamic Monitoring in Shock and Implications for Management

Sponsored in part by the Society of Critical Care Medicine (SCCM), an 11-person jury will convene in Paris, France April 27-28, 2006 to debate the following:

1. What are the epidemiologic and pathophysiologic features of shock in the ICU?
2. Should preload and fluid responsiveness in shock be monitored?
3. Should cardiac output in shock be monitored?
4. Should markers of regional circulation and oxygen consumption in shock be monitored?
5. Is there an evidence-based rationale for using hemodynamic monitoring in shock?

For more information visit www.srlf.org

Sidebar

No Patient Left Behind
Newer Alternatives Broaden Hemodynamic Monitoring of the Critically Ill

Merriam-Webster's Medical Dictionary defines hemodynamics as “a branch of physiology that deals with the circulation of the blood.” Responsible for delivering oxygen and other vital nutrients to internal organs — such as the heart and lungs — blood is at the core of the human body’s life support system. It’s no wonder then that hemodynamic monitoring, and its management of adequate organ perfusion, is a critical component of care in hospital patients and one whose importance cannot be over stated. What may be disputed, however, is the appropriateness of method(s) by which this is accomplished.

Methods for Management
Hemodynamic monitoring methods range from the most basic to more complex solutions and can include blood pressure and heart rate monitoring, ECG, pulse oximetry, cardiac output monitoring and pulmonary artery catheterization (PAC), among others. Although the PAC is considered the most comprehensive method of providing continuous hemodynamic information, it is not, however, without its drawbacks — namely the risk of infection — and as a result there has been a drop in use of the 30 -year-old monitoring standard. The PAC is now reserved primarily for patients with severe hemodynamic instability, but unfortunately this pendulum shift has left some patients unmonitored and, therefore, in potential jeopardy. So how do physicians effectively monitor their patients’ hemodynamic status without subjecting them to further harm?
The market has responded by providing less-invasive and noninvasive methods for patients whose conditions aren’t sufficiently critical to warrant use of a PAC. Involving a variety of monitoring methods, these solutions include the following:
FloTrac
Boasting accuracy comparable to thermal dilution, the FloTrac sensor from Edwards Lifesciences entered the market in April 2005. This less invasive alternative to the PAC utilizes a patient's existing arterial line to assess hemodynamic parameters. The sensor works with the Vigileo monitor to combine data from the arterial pressure line with other patient parameters to automatically calculate a patient's cardiac output on a continuous basis. After connecting the FloTrac to the patient’s existing peripheral arterial catheter, the user simply enters the patient’s age, gender, height and weight to initiate continuous cardiac output monitoring. There is no calibration required and the sensor automatically calculates key flow parameters while continuously compensating for changes in the patient’s vascular physiology.
“The FloTrac provides a quantitative assessment of how well the heart is working,” said Roy Wallen, Edwards’ director of Critical Care. It tells the clinician how much blood the heart is pumping on a per-beat basis or how much volume is being pumped per minute, Wallen says, providing information about stroke volume variation and letting the clinician know how well the patient is resuscitated from a fluid management point of view.
Used together, the FloTrac and the PreSep central venous oxygen saturation sensor produce an even higher level of hemodynamic information. The two “work together to provide cardiac output measurement — how well the heart is working — and how well the tissues are being oxygenated,“ explained Wallen.

BioZ
A clinically viable technology since the late 1990s, impedance cardiography (ICG) is a noninvasive tool that allows clinicians access to highly accurate information to assess hemodynamic parameters. Cardiologist Neil Triester, M.D., has been using the BioZ ICG from Cardiodynamics for about three years both in his office practice and in the hospital. Although 80 to 90 percent of the device’s use is in the physician’s office, Dr. Triester says, the BioZ is also suited for use in a variety of hospital settings including the ED and ICU. He cites the recent ED Impact Study conducted through the Cleveland Clinic and the University of Mississippi on patients 65 and over presenting with shortness of breath, which documents BioZ’s positive impact on patient diagnosis and treatment tailoring.
The BioZ works through four sets of dual sensors — two placed on either side of the patient’s neck and two on either side of the chest at the mid-axillary line below the rib cage. As each heartbeat pulses blood into and out of the aorta, changes in impedance are processed to measure and calculate hemodynamic parameters, including cardiac output, stroke volume, systemic vascular resistance, contractility and fluid status.
This information is important for several reasons, says Dr. Triester. First, patients who are at highest risk can actually be identified and secondly, it allows physicians to guide their therapy. “The nice thing about this information is that it is dynamic; it is changing all the time. So, if you give medication, within minutes you can see its effect in terms of changing cardiac output or changing fluid status,” he said.
On a recent visit to Massachusetts General Hospital (MGH), Dr. Triester witnessed firsthand the use of BioZ on neurological ICU patients. Patients who have bleeding within the brain can develop a sudden and severe heart dysfunction, a stunned, shocked heart, so to speak, he says. MGH is using ICG to monitor those patients to help guide therapy and are finding it very helpful. As a result, “[ICG] is not only a great clinical tool, it’s a great research tool,” he explained.

PiCCO
PiCCO technology utilizes a central venous and arterial access catheter to provide minimally invasive continuous monitoring of hemodynamic and volumetric parameters. These parameters are determined intermittently by the transpulmonary thermodilution technique and/or determined continuously by arterial pulse contour analysis.
Frost & Sullivan was so impressed with PICCO, it awarded PULSION Medical Systems its 2005 Frost & Sullivan Technology Innovation & Leadership of the Year Award. Their decision was based, in part, on the technology’s ability to “deliver cardiac output, stroke volume, cardiac volume responsiveness, systemic vascular pressure and even extravascular lung water within 10 minutes of the initial insertion of the arterial catheter,” said research analyst Nathan Cohen. Also influential were the partnerships and integration of the technology with other monitoring companies, such as Philips Medical Systems, Draeger Medical, GE Healthcare and Spacelabs Medical. (Note: Not all parameters and integrated products are available in the U.S.)
For example, the Infinity PiCCO SmartPod, which was unveiled at MEDICA 2005, integrates PiCCO technology for complete circulatory function monitoring — including continuous cardiac output — with Draeger’s Infinity patient monitoring. Clinicians simply plug the PiCCO pod into the monitor for immediate access to the range of PiCCO-technology parameters. Currently not available in the U.S., SmartPod supports both adult and pediatric patients.

USCOM
Providing the previously underserved ED and PICU arenas with a completely noninvasive method for measuring hemodynamic instability, ultrasound cardiac output measurement (USCOM) from USCOM Ltd. measures cardiac output with Doppler ultrasound at the suprasternal notch to monitor aortic valve flow, and the left sternal edge to monitor pulmonary valve flow. The portable unit can be used on adult and pediatric patients, whether they are awake, intubated or unconscious. USCOM can detect low or high cardiac output states in sepsis, confirm normal circulatory function with no risk to the patient and assess hemodynamic response to fluid, inotropes and vasoactive therapy.
Robert N. Bilkovski, M.D., Henry Ford Hospital (Detroit, MI) is the lead investigator researching USCOM’s application in the ED and its potential role in the worldwide adoption of Early Goal Directed Therapy (EGDT). The validation study, which is a collaborative effort between Henry Ford’s surgery department and the division of critical care and trauma, currently has 30 to 40 patients enrolled and expanded in January into a multinational, multicenter study. The study, according to Dr. Bilkovski, determines USCOM’s abilities to measure cardiac output in the ICU in order to compare it to what investigators would consider industry-standard references.
“The biggest benefit of the USCOM device is that it really is a bedside device that provides cardiac output in real time,” Dr. Bilkovski said. In addition, the unit’s noninvasive approach, he believes, brings “ICU-type mentality” into other hospital and nonhospital settings. He sees increased potential for the device in the area of congestive heart failure and the ability to predict and improve outcomes.
“My long-term belief is that the USCOM, if put into clinical practice, would be able to realize improved outcomes specifically in the management of severe sepsis or septic shock. It would be a very helpful adjunct in EGDT,“ Dr. Bilkovski said.

With a variety of methods available, more patients can benefit from hemodynamic monitoring without incurring unnecessary risk. When determining the solution that’s best for their patients, physicians should first adequately assess the patient’s level of acuity. Secondly, they must be familiar with the specific indications and possess the “how to” knowledge for these solutions.

  • Cardiodynamics' BioZ impedance cardiography