Postoperative remote monitoring of vital signs in older cardiac surgery patients

The number of elderly patients scheduled for cardiac surgery is increasing
rapidly. An increased life expectancy and improvements in surgical and
anesthetic techniques make it possible for older patients to undergo higher
risk surgery. Cardiac surgery in elderly patients aims to improve functional
capacity and overall survival but may also precipitate major morbidity and
mortality. Despite major improvements in the safety of anesthesia and surgery a
significant number of elderly patients experience a complication after cardiac
surgery.

During the early postoperative period, cardiac surgery patients are routinely
monitored at the Intensive Care Unit (ICU). Continuous monitoring of PR, RR and
SpO2 enables nurses and physicians to act immediately when vital signs are
deteriorating in order to reduce postoperative morbidity. However, the majority
of complications after cardiac surgery occur after several postoperative days
at the general ward. An explanation for surgery-related complications may be
the absence of continuous monitoring and standardized protocols for
postoperative care after a patient is discharged from the ICU. Medical
deterioration of patients is often preceded by subtle changes of vital signs.
Although vital parameters are routinely measured by a nurse at a surgical ward,
in many patients these measurements are only performed once every 8 hours.
Despite the risk of a significant delay in detection of compromised respiratory
or hemodynamic parameters, measurements are often inaccurate or incompletely
documented in the medical file due to high working load. As a result, early
deteriorations in vital functions are easily missed. To optimize patient safety
and reduce risk of potential inaccurate measurements, continuous remote
monitoring of vital signs in high risk patients may be considered as an
alternative.

To determine the incidence and severity of deteriorating vital signs in frail
cardiac surgery patients after ICU discharge using continuous remote
monitoring.

The central hypothesis of this study is that deteriorating vital signs are
common and often prolonged in older cardiac surgery patients after ICU
discharge. Our secondary hypothesis is that treatment with high risk
medications in older cardiac surgery patients is associated with deterioration
of vital signs.

• Single center pilot study.
• 100 older patients undergoing cardiac surgery.
• Continuous remote monitoring of vital signs starts at arrival on the general
ward after ICU discharge during 3 consecutive days (figure 1).
• PR, RR and SpO2 will be continuously monitored in all patients.
• Patients and healthcare personnel are blinded for monitoring results.
• Main study endpoint is the occurrence of vital deterioration.

Remote monitoring of vital signs is without additional risk of the patient. A
patient will wear a wireless sensor (arm band with finger sensor and acousitic
neck sensor) for 72 consecutive hours.