Cardiac arrest in operation room – risk factors for poor outcome
Leila Niemi-Murola, Emmi Lind, Tomi Niemi, Irma Jousela
Background: Unexpected perioperative cardiac arrest is a rare event (1, 2). During emergency operations for unstable patients there is always a risk for cardiopulmonary resuscitation. The current resuscitation guidelines emphasize prevention of in-hospital cardiac arrest (3). The aim of this pilot study was to analyze the risk factors of perioperative cardiac arrest.
Materials and methods: Data about perioperative cardiac arrests was extracted from the electronic patient records (Picis, Uranus) of the operation room of Meilahti hospital, Helsinki, Finland during years 2010-2014. The OR is one of the busiest in Finland, having 12 400 operations per year, 6 550of them emergencies. 
Results and discussion: During five years, there were 81 patients (50 male, 31 female) having perioperative cardiac arrest and 51 of them died. Cardiac arrest took place in emergency operations (70% vs. 83%). Those who survived were more often operated on during office the hours than those who died (70.0% vs. 54.9%). Majority of those who died, (group D), arrived from the emergency room than those who survived (group S), 83% vs. 70%., respectively (p<0.01). Patients in both groups were had high ASA grading and majority of them were elderly having multiple diseases. Twenty-one patients (41.2%) of group Died were resuscitated even before anaesthesia induction, initial rhythm being VF in nine cases, PEA in 6, ASY in two cases. 
In both groups cardiac arrest took place during the operation (group S 50.0%, group D 54.9%)(NS). In group D, the most common rhythm was PEA (80.4% in group D vs. 60.0% in group S)(p<0.05), followed by ASY (20.0% vs 17.6%) and VF 1.9% vs (20.0%). In group D, 67% of patients were resuscitated twice or more before the team decided not to start a new intraoperative attempt. In group S 76.7% of patients had perioperative noradrenalin infusion and 84.3%  in group D 84.3%, the latter group had also other vasoactive infusions.  Of those who survived surgery, 13 died later, 13 were transferred to a ward in other institution and five were discharged home. 
Conclusion: Preoperative cardiac arrest and emergency operation outside office hours are associated with poor outcome. The most frequent cause of death was failing haemodynamics. Further studies are needed is order to confirm the risk factors emergency anaesthesias. 


References:
1.	Andres J. et al. EJA 2013; 30: 95-96.
2.	Tikkanen J et al. Acta Anaesthesiol Scand 1995; 39: 262 – 7.
3.	Truhlar A et al. Resuscitation 2015; 95: 148-201.

Cardiac arrest in operation room - risk factors for poor outcome