SEATTLE — Patients who present with potential acute coronary syndrome might be most vulnerable to the downside of emergency department crowding, according to a small, single-center study at an academic medical center.
These patients eventually have worse outcomes, said Dr. Jesse Pines, who presented an analysis of 7 years of data from an ongoing prospective cohort study at the Hospital of the University of Pennsylvania, in Philadelphia, which has 55,000 annual patient visits. Dr. Pines, associate director of health care policy research at the university's emergency medicine department, spoke at the annual meeting of the American College of Emergency Physicians.
While there have been many studies of the impact of emergency department crowding and boarding (keeping patients who need inpatient care in emergency department rooms or hallways when the hospital has no beds to spare), few have focused specifically on patients with potential acute coronary syndrome, Dr. Pines said. And yet, there are 6 million ED visits a year for chest pain. Studies have shown that early treatment is very beneficial in ACS, so Dr. Pines and his colleagues wanted to gauge the impact of crowding or boarding—which can cause treatment delays—on potential ACS. Because ACS is difficult to identify, delays could have particularly crucial impacts on long-term outcomes.
Dr. Pines and his colleagues analyzed data from 6,869 patients who were older than 30 years and presented with chest pain. Fifty-seven percent (3,915) were women, and 69% (4,739) were African American. The mean age was 52 years.
Data were collected on patient characteristics and Thrombolysis in Myocardial Infarction scores, and outcomes were recorded for the 30 days following admittance to the hospital or discharge. The primary outcome was any cardiovascular event from 6 hours after arrival at the ED to 30 days out. Validated crowding measures were assigned at triage.
The researchers also took stock of process of care measures, including whether patients received an electrocardiogram within 10 minutes of arrival and whether they were prescribed aspirin and β-blockers in the ED.
Overall, 33% of the patients had an ECG, 57% received aspirin, and 80% were given β-blockers. Thirty-three percent of patients were treated and discharged, and 67% were admitted.
There were 301 cardiovascular complications in the overall cohort of 6,869 patients. Seventy-two patients died within 30 days.
The authors also tracked rehospitalization rates; so far, data are complete for 3,806 of the 6,869 patients. Ten percent (389) were readmitted within 30 days of the initial ED visit.
The median for patient-care hours was 98. This is the sum of all the hours that all the patients at that time had spent in the ED. Basically, if all patients were given a timer when they arrived, the patient-care hours would be all the hours on all the timers at any point, according to Dr. Pines. The ED occupancy rate was 60%, the number of patients in the waiting room was eight, and nine admitted patients were boarding in the ED.
The adjusted analysis showed that two factors were independently associated with increased incidence of cardiovascular complications in patients presenting with potential ACS: more than 12 patients in the waiting room, and total patient-care hours greater than 142, said Dr. Pines.
He and his colleagues also found that for all chest pain patients, increased ED occupancy rate, higher number of patients waiting, and higher total patient-care hours led to an increased risk of complications.
Because crowding seemed to affect both potential ACS and a subset of patients (12%, or 824 patients) who had unstable angina or myocardial infarction, it could be that crowding itself is not the problem but a symptom of overall hospital dysfunction, said Dr. Pines.
The hospital tends to function well for very sick patients, who are easily diagnosed and treated, he said. But it appears to do less well for patients whose conditions are less easily identified—particularly those with potential ACS.
Because ED crowding appears to be predictive of increased complications in those patients, Dr. Pines said, “to improve therapy of potential ACS, we should improve the crowding.”