Advances in technology have led to the use of wearable patient-monitoring equipment in a variety of healthcare settings. Patient wearable technology encompasses devices with sensors that can detect glucose levels, body position, and activity, among other things. This type of technology allows for noninvasive frequent measurements, or continuous monitoring, and may be particularly useful in the intensive care setting.

Patients in the ICU often require extensive monitoring, which can be time-consuming for staff. Patient wearable technology can save time, prevent medical errors, and prevent or minimize potential adverse events.1 Commonly used invasive monitoring techniques, such as intra-arterial continuous glucose monitoring (IA-CGM) and finger-stick glucose monitoring, may cause the patient discomfort or result in adverse events. Patient wearable technology spares the patient from commonly used invasive monitoring techniques, leading to increased patient satisfaction and mobility while reducing pain and adverse events associated with invasive types of monitoring. Patient wearable devices, such as subcutaneous continuous glucose monitors, sensors designed to track patient turning, and noninvasive mobility sensors, are especially helpful tools for use in the ICU, while other types of patient wearables can help keep patients safe at home after discharge from the ICU.

Glucose monitoring

Glucose monitoring is crucial to safe glycemic control, particularly in the ICU. Current glucose measurement methods involve point-of-care glucose meters and blood gas results. Since these methods are not continuous, episodes of hypoglycemia and hyperglycemia, which can occur between readings, are often overlooked.1 Hypoglycemia has been linked to an increase in respiratory complications and prolonged ICU and hospital stays.2 Current glucose measurement methods (point-of-care glucose meters) can be time-consuming for staff caring for patients who require frequent glucose monitoring. In addition, frequent finger sticks can cause the patient pain and leave scars. The use of CGM has been shown to drastically decrease the clinical workload.3

There are two types of CGM used in the ICU: IA-CGM and subcutaneous CGM (SC-CGM). An SC-CGM is a device that uses an electrochemical sensor to measure glucose levels every minute through a glucose oxidase method. It is inserted in the adipose tissue, most commonly on the abdomen.4 There are several SC-CGM systems available. CGM systems must be removed prior to magnetic resonance imaging. Many have the capability to set limits to notify the healthcare provider of critically low or high results.5 Comparable accuracy of IA-CGM and SC-CGM in cardiac ICU patients has been demonstrated.2,4

Pressure injury prevention

Hospital-acquired pressure injuries (HAPIs) account for approximately $11 billion in healthcare spending each year.6 In 2011, any hospital-acquired Stage 3, Stage 4, and Unstageable Pressure Injuries were deemed a "never event" by the National Quality Forum.7 In 2011, the Centers for Medicare and Medicaid Services stopped reimbursing for pressure injuries acquired in a hospital setting.8 After this significant change, a study conducted by Padula and colleagues exposed a steep reduction in HAPIs.9 It is estimated that the adherence to protocols for proper patient positioning is 38% to 51% in the ICU.6 Adherence is noticeably lower in the ICU than other units, such as medical-surgical; possible reasons for this adherence disparity are ineffective turning reminders or alerts, understaffing, a busy environment, patients who are too unstable to turn, and patient nonadherence.6

The Leaf Patient Monitoring System by Leaf Healthcare, Inc., is an example of a wearable technology that can help prevent pressure injuries by allowing clinical staff to determine which patients need help turning and when they need to be repositioned. This device, a small wearable patient sensor, is applied to the patient's chest and assesses the patient's body position. It determines the patient's relative body position within a three-dimensional space. Data from the sensor are relayed wirelessly to a central monitoring station known as the User-Dashboard. The data are updated on the display every 10 seconds to help healthcare providers identify patients who need turning. This device is linked to enhanced turning adherence, resulting in reduced HAPI rates.8

Patient mobility measurement

There are numerous benefits to early mobilization in ICU patients, including fewer physical injuries, reduced duration on a mechanical ventilator, and decreased length of hospital stay. Measurement of patient mobility can be done by direct observation or by sensor. Direct observation through methods such as behavioral mapping can be subjective, biased, and inconsistent throughout the day.10

Another method of measurement is the use of a noninvasive mobility sensor (NIMS). A NIMS uses machine-acquired sensors and computer vision technology to spontaneously monitor a patient's movement. The movement data are collected by healthcare practitioners from sensors that are connected to computers. This novel technology has the potential to improve the quality of patient care. NIMS is an innovative and practical method for evaluating mobility in patients in the ICU.10

Postdischarge implementation

Patient wearable technology is not only useful in the hospital, but can provide benefits to patients recovering from critical illness outside of the hospital as well. Commercially available wrist-worn personal fitness trackers can detect activity, and provide information on sleep, heart rate, and movement. These wearable devices use photoplethysmography (PPG) sensors to detect the heart rate and accelerometers to track activity.11 Through these PPG sensors, clinical deterioration related to the heart rate (including bradycardia and tachycardia) have the potential to be recognized. Changes in heart rate can lead to identification of cardiac rhythm changes. PPG-based wearable devices have been shown to have high rates of sensitivity and moderate specificities. Sleep quality detected by these wearable devices also correlated with questionnaire data.11

Just the beginning

While this may be just the beginning, patient wearables are predicted to become more commonly used in critical care settings. There are still many aspects of these technologies to consider and more studies are needed to determine the accuracy, applicability, and practicality related to each specific wearable, but there is no doubt that patients can benefit from this innovative technology. In addition, patient wearables provide numerous benefits to nurses, such as freeing up time to provide better-targeted patient care. Whether used to monitor glucose, prevent pressure injuries, or track patient activity, patient wearables are invaluable new tools for the clinical setting.

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