Unplanned transfer from the telemetry unit to the intensive care unit in hospitalized patients with suspected acute coronary syndrome

Abstract

Background: Most patients presenting with suspected acute coronary syndrome (ACS) are admitted to telemetry units. While telemetry is an appropriate level of care, acute complications requiring a higher level of care in the intensive care unit (ICU) occur.

Purpose: Among patients admitted to telemetry for suspected ACS, we determine the frequency of unplanned ICU transfer, and examine whether ECG changes indicative of myocardial ischemia, and/or symptoms preceded unplanned transfer.

Method: This was a secondary analysis from a study assessing occurrence rates for transient myocardial ischemia (TMI) using a 12-lead Holter. Clinicians were blinded to Holter data as it was used in the context research; off-line analysis was performed post discharge. Hospital telemetry monitoring was maintained as per hospital protocol. TMI was defined as >1mm ST-segment ↑ or ↓, in >1 ECG lead, >1minute. Symptoms were assessed by chart review.

Results: In 409 patients (64±13years), most were men (60%), Caucasian (93%), and had a history of coronary artery disease (47%). Unplanned transfer to the ICU occurred in 9 (2.2%), was equivalent by gender, and age (no transfer 64±13years vs transfer 67±11years). Four patients were transferred following unsuccessful percutaneous coronary intervention (PCI) attempt, four due to recurrent angina, and one due to renal and hepatic failure. Mean time from admission to transfer was 13±6hours, mean time to ECG detected ischemia was 6±5hours, and 8.8±5hours for symptoms prompting transfer. In two patients ECG detected ischemia and acute symptoms prompting transfer were simultaneous. In five patients, ECG detected ischemia was clinically silent. All patients eventually had symptoms that prompted transfer to the ICU. In all nine patients, there was no documentation or nursing notes regarding bedside ECG monitor changes prior to unplanned transfer. Hospital length of stay was longer in the unplanned transfer group (2days ± 2 versus 6days ± 4; p=0.018).

Conclusions: In patients with suspected ACS, while unplanned transfer from telemetry to ICU is uncommon, it is associated with prolonged hospitalization. Two primary scenarios were identified; (1) following unsuccessful PCI, and (2) recurrent angina. Symptoms prompting unplanned transfer occurred, but happened on average 8.8 hours after hospital admission; whereas ECG detected ischemia preceding unplanned transfer occurred on average 6 hours after hospital admission.

Keywords: 12-lead; Acute coronary syndrome; Holter; ICU; Myocardial ischemia; Telemetry unit; Unplanned transfer.

Figure 1

Figure A ST-segment trend in 11 electrocardiographic (ECG) leads (Y-axis; lead - aVR not shown) from a Holter recording during six hours (X-axis) of recording. While awaiting cardiac catheterization, three transient myocardial ischemic events occurred (*); 1106, 1255, and 1315 (ST elevation V1 – V4). Following cardiac catheterization and failed percutaneous coronary intervention (PCI) there is on-going ischemia (arrow). The patient was transferred back to the telemetry unit, and approximately one hour later a code blue was called due to acute pulmonary edema (arrow). Figure B. 12-leads ECG prior (top) to and during (bottom) transient myocardial ischemia.; Prior to Transient Myocardial Ischemia (10:40:56); During Transient Myocardial Ischemia (11:06:03) Figure C. The top 12-lead ECG was obtained prior to cardiac catheterization. The bottom 12-lead ECG was obtained when Holter monitoring was resumed after cardiac catheterization and failed percutaneous coronary intervention.

Figure 1

Figure A ST-segment trend in 11 electrocardiographic (ECG) leads (Y-axis; lead - aVR not shown) from a Holter recording during six hours (X-axis) of recording. While awaiting cardiac catheterization, three transient myocardial ischemic events occurred (*); 1106, 1255, and 1315 (ST elevation V1 – V4). Following cardiac catheterization and failed percutaneous coronary intervention (PCI) there is on-going ischemia (arrow). The patient was transferred back to the telemetry unit, and approximately one hour later a code blue was called due to acute pulmonary edema (arrow). Figure B. 12-leads ECG prior (top) to and during (bottom) transient myocardial ischemia.; Prior to Transient Myocardial Ischemia (10:40:56); During Transient Myocardial Ischemia (11:06:03) Figure C. The top 12-lead ECG was obtained prior to cardiac catheterization. The bottom 12-lead ECG was obtained when Holter monitoring was resumed after cardiac catheterization and failed percutaneous coronary intervention.

Figure 1

Figure A ST-segment trend in 11 electrocardiographic (ECG) leads (Y-axis; lead - aVR not shown) from a Holter recording during six hours (X-axis) of recording. While awaiting cardiac catheterization, three transient myocardial ischemic events occurred (*); 1106, 1255, and 1315 (ST elevation V1 – V4). Following cardiac catheterization and failed percutaneous coronary intervention (PCI) there is on-going ischemia (arrow). The patient was transferred back to the telemetry unit, and approximately one hour later a code blue was called due to acute pulmonary edema (arrow). Figure B. 12-leads ECG prior (top) to and during (bottom) transient myocardial ischemia.; Prior to Transient Myocardial Ischemia (10:40:56); During Transient Myocardial Ischemia (11:06:03) Figure C. The top 12-lead ECG was obtained prior to cardiac catheterization. The bottom 12-lead ECG was obtained when Holter monitoring was resumed after cardiac catheterization and failed percutaneous coronary intervention.