Remote Monitoring of ICU Patients Does Not Improve Outcomes
By Fran Lowry
Medscape Medical News
December 29, 2009 — Remote monitoring of patients in intensive care units (ICUs) does not appear to improve their mortality or reduce length of stay in the ICU or hospital, according to an observational study published in the December 23/30 issue of the Journal of the American Medical Association.
"Telemedicine technology, which can enable intensivists to simultaneously monitor several [ICUs] from an off-site location, is increasingly common, but there is little evidence to support its use," write Eric J. Thomas, MD, MPH, from the University of Texas Health Science Center, Houston, and colleagues. "Furthermore, it is not known whether remote monitoring by intensivists would benefit all or only a subset of ICU patients."
The aim of this study was to assess the effect of remote monitoring in the ICU on mortality, complications, and length of stay.
The researchers measured these outcomes before and after remote monitoring was implemented in 6 ICUs of 5 hospitals in a large, nonprofit healthcare system located in the Gulf Coast region of the United States.
The study included 2034 patients in the preintervention period (January 2003 - August 2005) and 2108 patients in the postintervention period (July 2004 - July 2006).
Local physicians delegated full treatment authority to the telemedicine ICU (tele-ICU) for 655 patients (31.1%) and authority to intervene only in life-threatening events for the remaining 1393 patients.
Telemedicine ICU Design
The tele-ICU system consisted of a remote office located in the administrative offices of the healthcare system, separate from all the hospitals. It was equipped with audiovisual monitoring apparatus and was staffed by 2 intensivists from noon to 7 am Monday through Friday and 24 hours a day on Saturday and Sunday.
Each intensivist worked with 2 nurses and 1 technician to monitor half of the ICU beds. They sat at computer workstations that provided real-time vital signs with graphic trends, audiovisual connections to patients' rooms, early warning signals regarding abnormalities in a patient's status, and access to imaging studies and medication administration records.
The study found that the observed hospital mortality rates were 12.0% (95% confidence interval [CI], 10.6% - 13.5%) in the preintervention period and 9.9% (95% CI, 8.6% - 11.2%) in the postintervention period, for an overall decrease in mortality rates of 2.1% (95% CI, 0.2% - 4.1%; P = .03).
Observed ICU mortality rates in the preintervention period were 9.2% (95% CI, 8.0% - 10.5%) and 7.8% (95% CI, 6.7% - 9.0%) in the postintervention period, for a preintervention to postintervention decrease of 1.4% (95% CI, ?0.3% to 3.2%; P = .12).
After adjustment for severity of illness, there were no significant differences associated with the telemedicine intervention for hospital or ICU mortality. However, there was a significant interaction between the tele-ICU intervention and severity of illness (P < .001). Remote monitoring was associated with improved survival in sicker patients, but with no improvement or worse outcomes in less sick patients, the authors report.
The observed average hospital length of stay among patients who survived to discharge was 9.8 days preintervention and 10.7 days postintervention. The observed average length of stay in the ICU for patients who survived to transfer was 4.3 days for the preintervention period vs 4.6 days for the postintervention period.
Significance of Effect on Sickest Patients Unknown
The authors point out that they have no data on survival after hospital discharge and suggest that the tele-ICU intervention may have led to the sickest patients being transferred more quickly to hospice or other sites of care where they died. This may have been an appropriate improvement in care, but without postdischarge survival data it is not possible to know whether the significant reduction in hospital mortality that was seen in the sickest patients translates to the same reduction in long-term mortality.
Another potential limitation of the study could be detection and surveillance bias, which may have led to increased surveillance and documentation of complications by the physicians and nurses doing the remote monitoring, the authors suggest.
They conclude, "Given the expense of tele-ICU technology, the conflicting evidence about its effectiveness, and the existence of other effective quality improvement interventions for ICUs, further use of this technology should proceed in the context of careful monitoring of patient outcomes and costs."
In an accompanying editorial, Erika J. Yoo, MD, and R. Adams Dudley, MD, MBA, from the University of California–San Francisco, write that evaluating the effectiveness of telemedicine in the ICU is challenging.
"Given the heterogeneity of the tele-ICU systems and the hospitals adopting them, it is unlikely that any single study can definitely address the benefits of telemedicine for the critically ill," they write. "Rather, literature syntheses will be the most important approach to improving the understanding of the effects of tele-ICU support."
The editorialists conclude, "Synthesis of this literature with an eye to sequential hypothesis testing of remote monitoring and parallel hypothesis testing for other important elements of ICU care would help to determine when and how to use tele-ICU."
Dr. Thomas, Dr. Yoo, and Dr. Dudley have disclosed no relevant financial relationships.
