Background
Isolation of patients in single-patient rooms for infection control precautions is a daily practice to reduce the propagation of various infectious agents. Isolation of patients leads to less contact with medical staff. Our objective was to assess whether isolated patients who suffer an in-hospital cardiac arrest (IHCA) have lower survival to hospital discharge as non-isolated IHCA patients.

Methods
We screened 75.987 patients for IHCA occurrence and the isolation state at the time-point of IHCA who had been hospitalised from 2014 to 2018 at the internal medicine or neurology departments at the university hospital.

Results
From 2014 to 2018, 4.249 out of 75.987 patients (5.6%) had to be isolated for infection control precautions. IHCA occurred in 32 (0.8%) of these isolated patients and in 410 out of 71.738 non-isolated patients (0.6%) (p=0.130). Overall, there was no difference in most baseline characteristics, aetiology, and characteristics of cardiac arrests between the groups. The proportion of patients who achieved a return of spontaneous circulation (ROSC) (53% vs. 76%, p=0.005) and time to achieve ROSC (10 (3, 25) min. vs. 20 (12, 25) min, p= 0.031) was lower in isolated patients than in non-isolated patients.

Only one out of 32 isolated patients (3.1%) survived to discharge after IHCA compared to 155 out of 410 non-isolated patients (37.8%) (p< 0.0001). The Kaplan-Meier curve and log-rank (Mantel-Cox) test confirmed a lower survival to discharge of isolated patients. None of the 32 isolated patients were discharged with good neurological outcomes compared to 97 out of 410 non-isolated IHCA patients (23.7%) (p=0.0020).

In the multivariate analysis, patient isolation (odds ratio [OR] 18.985, 95% confidence interval [CI] 2.467–1.328, p=0.005) was an independent predictor of poor survival after IHCA along with advanced age, worse renal function and non-cardiac arrest aetiology.

Conclusion
Isolation of patients for infection control precautions is associated with considerable poorer survival and neurological outcome in case these patients are suffering an IHCA.