Background: Effectiveness of cooling and adverse events (AEs) involving skin have not been intensively evaluated in cardiac arrest survivors treated with therapeutic hypothermia (TH) when induced and maintained with a servomechanism-regulated surface cooling system.
Methods: Retrospective review of sixty-nine cardiac arrest survivor-events admitted from April 2006-September 2008 who underwent TH using the Medivance Arctic Sun Temperature Management System. A TH database and medical records were reviewed, and nursing interviews conducted. Primary endpoint was time from initiation to target temperature (TT; 32-34 °C). Secondary endpoints were cooling rate, percentage of hypothermia maintenance phase at TT, effect of body-mass index (BMI) on rate of cooling, and AEs.
Results: Mean time to the target temperature (TT) was 2.78 h; 80% of patients achieved TT within 4 h; all did within 8 h. Patients were at TT for 96.7% of hypothermia maintenance; 17% of patients had >1 hourly temperature measurement outside TT range. Mean cooling rate during induction phase was 1.1 °C/h, and was not associated with BMI. Minor skin injury occurred in 14 (20%) patients; 4 (6%) were device-related. Skin injuries were associated with shock (P = 0.04), and decubitus ulcers were associated with left ventricular ejection fraction <45% (P = 0.004). AEs included shivering (94%), hypokalemia (81%), hyperglycemia (57%), pneumonia (23%), bleeding (22%), post-cooling fever (17%), and bacteremia (9%).
Conclusions: The Arctic Sun Temperature Management System was an effective means of performing therapeutic hypothermia after cardiac arrest. Infrequent skin injuries were associated with vasopressor use and low ejection fraction.