A new study published in JAMA found that when a critical illness event occurs in a hospital ward, there is a cascading negative effect on other patients in the same ward, including increased risk of cardiac arrest and transfer to ICU, and delayed hospital discharge.

Major critical illness events, such as cardiopulmonary arrest and intensive care unit (ICU) transfer, disrupt workflow in a hospital ward. Other patients on the same ward may receive inadequate attention, especially if their care team is distracted by the emergency.

This study of adult admissions (2009-2013) at the University of Chicago Medicine where rapid-response teams were used included 13 medical-surgical wards that were geographically distinct areas, had patient-nurse ratios of 4:1 on average and 1 charge nurse, and had approximately 20 beds per ward.

Physician teams consisted of 1 attending and 2 to 3 resident trainees or a hospitalist. The researchers examined the number of patients on the same ward experiencing a critical illness event (cardiac arrest, ICU transfer, or death) anytime during the prior 6 hours.

Of 83,723 admissions, 4,286 experienced the primary outcome (179 cardiac arrests and 4,107 ICU transfers). The likelihood of cardiac arrest or ICU transfer within the next 6 hours was greater when 1 event (5.0 per 1,000-patient 6-hour blocks) or more than 1 event (7.1 per 1,000-patient 6-hour blocks) occurred during the prior 6 hours compared with no event (3.6 per 1,000-patient 6-hour blocks).

In the fully adjusted model, when 1 or more patients developed critical illness, other ward patients’ risks for cardiac arrest or ICU transfer increased over the next 6 hours (1 event: adjusted absolute risk increase of 0.6 per 1,000-patient 6-hour blocks); greater than 1 event: adjusted absolute risk increase of 1.9 per 1,000-patient 6-hour blocks).

Critical illness events were also associated with a decrease in other patients being discharged from the hospital within the next 6 hours.

“Although the absolute increased risk was small, these events were associated with high morbidity and mortality,” the authors write. “The association may be explained by the diversion of resources to critically ill patients, which may result in caregivers being less attentive to other ward patients.”