For decades, medical recovery stories of individuals who have fallen into icy waters or were buried under avalanches have left researchers intrigued by the beneficial effects of hypothermia.   Peter Safar, MD, FCCM intrigued by this process, believed hypothermia should be used for the protection, preservation or resuscitation of critically ill patients.  The potential utility of therapeutic hypothermia has brought forth much debate.  Uses of therapeutic hypothermia range from patients with stroke, traumatic brain injury, perinatal asphyxia and central nervous system insults in the pediatric population.  Therapeutic hypothermia has many potential uses in critical care from the adult to the newborn but also poses many potential challenges. Optimized management of critically ill patients who are cooled requires discussions related to timing, duration, re-warming and the impact on coagulation, infection control and drug metabolism and interactions.  
  
The Society of Critical Care Medicine (SCCM) hosted the 11th International Consensus Conference (ICC) "Therapeutic Hypothermia- To Cool or Not to Cool?".  This two day conference used experts from different disciplines to present findings from the literature and provide answers to the five (5) questions.
 
The five questions to be answered are:

1. What is Mild Therapeutic Hypothermia?
2. Where is the Clinical Evidence Supporting the Use of Mild Therapeutic
    Hypothermia?
3. Who Else Might We Cool?
4. How Should We Cool? The Devil is in the Details!
5. Why We Should Not Cool?

The ICC is supported by five critical care societies:

American Thoracic Society
European Respiratory Society
European Society of Intensive Care Medicine
Society of Critical Care Medicine
Société de Réanimation de Langue Française

Below are the presentations of that conference.

1. What Is Mild Therapeutic Hypothermia?

In this section, the presenters discuss the evidence that defines mild therapeutic hypothermia and the effect therapeutic hypothermia has on the patient who presents with a central nervous system injury.  

- David S. Warner, MD - What Are Definitions and Physiological Effects of Mild Hypothermia?

- Patrick M. Kochanek, MD, FCCM - Molecular Biology of Mild Hypothermia in CNS Injury: What Does It Effect?

2. Where is the Clinical Evidence Supporting the Use of Mild Therapeutic
    Hypothermia?

This section discussed the use of therapeutic hypothermia in the various life-threatening conditions.  The evidence is variable on whether this helps to reduce cerebral injury during hypoxic states.

- Wilhelm Behringer, MD - In Ventricular Fibrillation Cardiac Arrest in Adults?

- Michael Holzer, MD - In Non-Ventricular Fibrillation Cardiac Arrest in Adults?

- Seetha Shankaran, MD - In Perinatal Asphyxia?

- Donald W. Marion, MD, MSc  - In Traumatic Brain Injury Patients - Does It Help with Intracranial Pressure Control?

3. Who Else Might We Cool?

This section identifies patients with life threatening conditions and the evidence that may or may not support the use of therapeutic hypothermia in resuscitating them.

- Simon R. Dixon, BHB, MBChB - Patients with Myocardial Ischemia?

- Stefan Schwab, MD, PhD, BHB - Patients with Stroke?

- Jamie S. Hutchison, MD - Patients with Pediatric Central Nervous System Insults?

- W. Dalton Dietrich III, PhD - Patients with Spinal Cord Injury

- Samuel A. Tisherman, MD, FCCM - Patients with Other Critical Care Medicine-Relevant Conditions?

- Michael N. Diringer, MD, FCCM - Patients with Fever and Abnormalities in Temperature Control in the ICU?

4. How Should We Cool? The Devil is in the Details!

The presenters identify the various tools used to cool patients and their effectiveness in the cooling process.   Dr. Dietrich provides the evidence for which medications can be used during the cooling of patients with cardiac arrest, stroke and traumatic brain injury.   Re-warming patients can pose significant challenges for health care practitioners. The discussion by Drs. Povlishock and Kochanek provide the evidence to the approaches to safely re-warming the patient.

- Francis Kim, MD - With Intravenous Fluid Cooling?

- Kjetil Sunde, MD, PhD - With Surface Cooling?

- Ken Nagao, MD - With Invasive Cooling?

- Fritz R. Sterz, MD - At What Temperature Should We Monitor?

- Nicolas Deye, MD - When Should We Initiate Cooling and for How Long?

- W. Dalton Dietrich III, PhD - What Drugs Should We Use to Supplement in Cardiac Arrest, Traumatic Brain Injury, and Stroke?

- John T. Povlishock, PhD - How Do We Re-Warm? Pathophysiology and Clinical Approaches

- Patrick M. Kochanek, MD, FCCM - How Do We Re-Warm? Clinical Considerations

5. Why We Should Not Cool?

This session describes the complications when using therapeutic hypothermia as a treatment modality. The presenters discuss the complications of its use and it is left up to you to decide if the complications outweigh its benefits. 

- Samuel M. Poloyac, PharmD, PhD - Implications of Hypothermia on Drug Metabolism and Interactions?

Special Presentation

This presentation is an overview of the current trials using therapeutic hypothermia in traumatic brain injury.  Dr. Andrew's research project is sponsored in part by the European Society of Intensive Care Medicine. 

- Peter Andrews, MD, MBChB - Traumatic Brain Injury: Trial Results

Critical Connections

Access the August 2009 issue of Critical Connections devoted to therapeutic temperature management in the intensive care unit. Articles include: 
- Hypothermia: Translating Research to Clinical Practice
- Pharmacological Management of Therapeutic Hypothermia-Induced Shivering
- Implementing Hypothermia After Cardiac Arrest
- Temperature Modulation for Neuroprotection After Acute Brain Injury