Indication‐specific event rates among hospitalized patients undergoing continuous cardiac monitoring

Abstract Background Cardiac telemetry monitoring is widely utilized for a variety of clinical indications, yet indication‐specific event rates for monitored patients are seldomly reported. Hypothesis High‐risk hospitalized patients for clinical deterioration can be identified using standardized telemetry monitoring indications. Methods Adjudicated data from events triggering emergency response team (ERT) activation were systematically characterized at the Cleveland Clinic from among standardized telemetry indications ordered over a 13‐month period. Results Among 72 199 orders created for telemetry monitored patients, ERT activation occurred in 2677 patients (3.7%), of which 1326 (49.5%) were cardiac‐related. Patients with deep venous thrombosis or pulmonary embolism (DVT/PE) demonstrated the highest overall event rate (ERT: n = 41 of 593 pts [6.9%]; 25/41 cardiac related [61%]). Cardiac‐related events were proportionally highest among patients with coronary disease awaiting revascularization (ERT: n = 19 of 847 patients [2.2%]; 13/19 cardiac‐related [68.4%]). Arrhythmia‐specific events were highest among patients who underwent cardiac surgery (n = 78 of 193 cardiac‐related ERT [40.4%]), and patients with known or suspected tachyarrhythmias (n = 318 of 788 cardiac‐related ERT [40.4%]). Bubble plot analysis identified patients hospitalized with DVT/PE, drug or alcohol exposures, and acute coronary syndrome as among the highest overall and cardiac‐related events while identifying patients with respiratory disorder monitoring indications as carrying the highest noncardiac event rate. Conclusion High‐risk hospitalized patients can be identified by telemetry indication and prioritized according to concerns for cardiac, arrhythmia‐specific and noncardiac clinical deterioration. This is particularly useful when monitored bed resources are constrained.


| INTRODUCTION
Cardiac telemetry monitoring is widely utilized for a variety of clinical indications, yet indication-specific event rates for monitored patients are seldomly reported. [1][2][3][4][5] The 2017 update to American Heart Association guidelines 6 call for additional research while endorsing standardized hospital-based monitoring practices. 7 Standardized cardiac telemetry monitoring, in accordance with practice guidelines, has been associated with decreased utilization, cost savings, and improved clinical outcomes. 1,2 Removing low-risk patients may mitigate alarm fatigue by reducing the volume of inactionable alarms. [3][4][5]8 In the ALARMED study, cardiac telemetry findings altered management in only 0.2% of low-risk patients admitted for chest pain despite generating an average 4.7 alarms per hour. 5 Delineating the indication-specific event rates for cardiac, noncardiac, and arrhythmia-specific clinical deterioration is therefore needed to improve risk stratification and prioritization, particularly when monitored bed resources are constrained. This aligns with patient safety goals set forth by the Joint Comission. 9 The present analysis therefore examined indication-specific adjudicated event rates during a previously reported 13-month period of applying standardized telemetry monitoring indications with an electronic order linked to offsite central monitoring. 1

| METHODS
Previously published standardized telemetry monitoring indications were systemically captured for noncritically ill hospitalized patients at the Cleveland Clinic using required electronic order entry over a 13-month period (4 March 2014 to 4 April 2015), as listed in Table 1  Other category: The largest group within this category was "hypotensive disease states" that included GI bleeding, sepsis/bacteremia, and pancreatitis (n = 607; <1%) with 40 ERT activations (6.6%) including 10 cardiac (25%), and eight rhythm-related (20%).
T A B L E 3 Cardiac-related emergency response team (ERT) event rates listed by telemetry indication in descending order occurring as a percentage of the total number of events (first column) and with the corresponding overall ERT event rate (second column) occurring as a percentage of the order volume The results of bubble plot analysis measuring order volume in addition to overall and cardiac-specific ERT activation event rates are shown in Figure 1. In this graph, the percentage of ERT activations is displayed on the Y axis with cardiac-specific events on the X axis, thereby creating visual representation of the indication-specific risk profile. For example, patients awaiting coronary revascularization appear in the lower right quadrant of this graph due to a low overall ERT event rate, but high proportion of cardiac events. Patients with deep venous thrombosis or pulmonary embolus feature both a high percentage of overall ERT and cardiac-related events, suggesting concern for both respiratory and cardiovascular events. Conversely, patients undergoing telemetry monitoring for respiratory disorders appear in the left upper quadrant as having a high overall event rate, but a low proportion of cardiac events. The lowest risk indications therefore cluster towards the lower left quadrant.
The size of each bubble indication is proportional to the number of telemetry orders generated in that category.

| DISCUSSION
The key finding of this analysis is that hospitalized patients at highest risk for clinical deterioration due to both cardiac and noncardiac causes, as measured by ERT activation, can be identified by telemetry monitoring indication, and thereby prioritized in moni- reported these data represent an important first step to facilitate future analysis of community hospitals and across a spectrum of clinical acuity. Second, the lack of demographic data for the monitored patients in this study prohibits a more enriched multivariable analysis according to age, sex, or disease-specific parameters. While perhaps amplifying selection bias, it also underscores the importance of foundationally grounding the need for telemetry monitoring using bedside clinical assessment within the framework of standardized indications.
Associated outcomes data are lacking in this field, and unfortunately seldom reported. Thirdly, several indications categorically combine patients of varying pathophysiology such as in the case of recreational drug and alcohol exposures. Regrettably, our data set does not allow the separation of these exposures as they were combined at the point of order entry. With that said, this indication does thematically capture the risk associated with substance abuse, as recreational drug exposures and alcohol intoxication often occur concomitantly. Yet, each drug exposure likely carries distinct risk and the authors recommend further evaluation in future studies. This is also likely true in the moderate sedation postprocedure and heart failure categories whereby the timing, total dosage and choice of drugs administered are likely contributory to specific event rates. Again, dedicated study of these populations utilizing enriched patient-specific data is needed.

| CONCLUSION
High-risk hospitalized patients for subsequent ERT activations can be identified by telemetry monitoring indication, and thereby prioritized when monitored bed resources are constrained according to concerns for cardiac, arrhythmia-specific, and noncardiac clinical deterioration.