Physician Utilization of Therapeutic Hypothermia Following Resuscitation from Cardiac Arrest

1. The University of Chicago Emergency Medicine Residency Physician Utilization of Therapeutic Hypothermia Following Resuscitation from Cardiac Arrest James W. Rhee, MD April 29, 2004

2. Introduction • Cardiac arrest • Greater than 90% mortality rate • No significant decline over past few decades despite new drugs and improved access to electrical defibrillation • Return of spontaneous circulation (ROSC) • Many patients go on to die during subsequent hospitalization • Neurologic impairment often remains as a lasting morbidity

3. Studies

4. ILCOR Advisory Statement • Unconscious adult patients with ROSC after out-of-hospital VF cardiac arrest should be cooled to 32°C - 34°C for 12 - 24 hours • Possible benefit for other rhythms or in-hospital cardiac arrest

5. Current Use • Physician Utilization • Physician utilization of therapeutic hypothermia following ROSC after cardiac arrest remains unclear • Physician Experience • Initial experiences with hypothermia • Guide future investigations • Development of critical pathways

6. Survey • We conducted an internet-based survey of U.S. physicians in emergency medicine, pulmonary/critical care, and cardiology • Evaluate physician utilization of hypothermia therapy • Assess physician opinions and experience regarding induced hypothermia after cardiac arrest

7. Methods • Institutional Review Board approval • Health Insurance Portability and Accountability Act of 1996 – compliant

8. Methods • 2000 electronic mail addresses randomly chosen • American College of Emergency Physicians • American Thoracic Society • American Heart Association • Invitation to participate in survey sent to each address with a hyperlink leading to the survey itself

9. Methods • Survey published via commercial survey provider (Infopoll.com, Dartmouth, Canada) • Survey comprised of twelve questions • Demographic information • Field of practice, geographic location, level of training, etc. • Use of induced hypothermia • Methodology, reasons for non-use, etc. • Free response at end of survey

10. Methods • Results compiled by survey provider software • Analysis and tabulation performed using a spreadsheet application (Excel, Microsoft Corp., Redmond, WA)

11. Results 265 responses (19%) 1400 hits 2000 emails

12. Demographics

13. Demographics 9% 30% 27% 13% 20%

14. Use of Therapeutic Hypothermia

15. Yes No Critical Care 29% 71% (n=33) Cardiology 11% 89% (n=64) Emergency 5% 95% Medicine (n=109) All respondents 13% 87% (n=263) Use of Therapeutic Hypothermia by Clinical Specialty

16. Reasons Against Use of Hypothermia as a Therapeutic Tool Reason for nonuse - Percentage of respondents 0% 10% 20% 30% 40% 50% Not enough data 49% Haven’t considered it 32% Not in ACLS guidelines 32% Too technically difficult 19% Current methods cool too slow 9% Unsatisfactory initial attempts 4%

17. Cooling Technique Cooling technique Percentage of respondents 0% 10% 20% 30% 40% 50% Cooling blankets 50% 15% Ice / cold liquid packing 13% Ice / cold liquid gastric lavage 2% IV cooling catheter 2% Cooling mist 17% Other method

18. Free Response

19. Hypothermia Not Yet Incorporated • Physicians have not yet incorporated the use of therapeutic hypothermia after cardiac arrest despite strong data and published guidelines recommending its use • This conclusion appears to be consistent across the three specialties queried

20. Limitations • Reflects practice at one point in time • Selection bias – respondent population was skewed towards physicians practicing in larger hospitals and teaching institutions • Western US not as well represented

21. Best Case • As physicians at academic institutions and tertiary or referral hospitals were overrepresented – likely represents best case of current practice • Assume  utilization of this new treatment modality in the greater medical community will be less than in larger academically-oriented hospitals

22. Reasons for Lack of Incorporation • Physicians not aware of strong literature supporting use of induced hypothermia • Not part of standard guidelines • Advanced Cardiovascular Life Support (ACLS) • Technical constraints

23. Actions to Promote Use • Physician education • Update ACLS • Share experiences and protocol development

24. Future Technology • Novel coolant fluids • Cold IV fluids • Cooling catheters

25. Research • Method • Timing • Mechanism

26. Summary • Physician use of hypothermia induction in patients resuscitated from cardiac arrest is low • Reasons why physicians have not used hypothermia include lack of awareness of supporting data, technical constraints, and the lack of hypothermia protocol incorporation into ACLS • Better understanding of the pathophysiology of resuscitation and the injury processes on which hypothermia acts will serve to further promote the use of this promising method to save lives

27. Acknowledgements Ben Abella, MD Annie Hueng Lance Becker, MD Terry Vanden Hoek, MD Lynne Harnish ERC