Serious adverse events in a hospital using early warning score - what went wrong?

To evaluate the performance of a new early warning score (EWS) system by reviewing all serious adverse events in our hospital over a 6-month time period.

All incidents of unexpected death (UD), cardiac arrest (CA) and unanticipated intensive care unit admission(UICU) of adult patients on general wards were reviewed to see if the escalation protocol that is part of the EWS system was followed in the 24h preceding the event, and if not where in the chain of events failure occurred.

We found 77 UICU and 67 cases of the combined outcome (CO) of CA and UD. At least two full sets of EWS were recorded in 87, 94 and 75% of UICU, CA and UD. Patients were monitored according to the escalation protocol in 13, 31 and 13% of UICU, CA and UD. Nurses escalated care and contacted physicians in 64% and 60% of events of UICU and the corresponding proportions for CO were 58% and 55%. On call physicians provided adequate care in 49% of cases of UICU and 29% of cases of the CO. Senior staff was involved according to protocol in 53% and 36% of cases of UICU and CO, respectively.

Poor compliance with the escalation protocol was commonly found when serious adverse events occurred but level of care provided by physicians was also a problem in a hospital with implemented early warning system. This information may prove useful in improving performance of EWS systems.