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In this second issue of 2015, we include two expert panel discussions that were held in the March 2015 Chilling at the Beach Scientific Symposium in Miami, Florida, that summarized recent discussions regarding the use of therapeutic hypothermia and targeted temperature management strategies in several experimental and clinical situations. One discussion focused on temperature management in the neurosurgical intensive care unit and during intraoperative procedures. In one session the use of therapeutic hypothermia for traumatic brain injury, subarachnoid hemorrhage, and spinal cord injury as well as intracranial hemorrhage was discussed. The importance of temperature precision and the current use of surrogate biomarkers to assess injury patterns of recovery was also emphasized.
Also in that panel discussion, experiences and recommendations for initiating new hypothermic programs in a hospital system were reviewed, emphasizing the complexity and multiple resources required for specific patient protocols. Another question and answer session brought together experts in the field of temperature management specifically targeting severe traumatic brain injury (TBI), intracranial hemorrhage, and state-of-the-art strategies to control intracranial pressure (ICP) in patient populations. Active clinical trials are ongoing, testing the effects of therapeutic hypothermia in trauma patients at multiple stages of therapeutic management.
A timely and important review article on the interpretation of the major findings of the recent Therapeutic Temperature Management Trial (TTM) in cardiac arrest is provided by Drs. Polderman and Varon. This TTM trial received better outcomes in control subjects than previous randomized control studies, and rates of good outcome in the hypothermia group were somewhat lower than previous studies. The authors provide various explanations and hypotheses regarding these interesting findings and emphasize that these issues should be discussed thoroughly before changes in guidelines and protocols are made.
Four original articles are also included in this issue. One study by Dr. Erlinge and colleagues discusses the beneficial effects of therapeutic hypothermia for the treatment of myocardial infarction. Pooled analysis of two clinical trials indicate a reduction of myocardial infarct size and reduction of heart failure with intravascular cooling in patients with large areas of myocardium at-risk. In another interesting article, the timing of induction of mild hypothermia having an effect on the survival duration of septic rats is presented by Dr. Leon and colleagues. This study reported a significant increase in the survival duration of septic rats, reporting that the earlier the hypothermia was applied, the better.
In another study, plasma levels of soluble urokinase activator receptor released in response to inflammatory stimuli was measured in 55 cardiac arrest patients treated with hypothermia. Finally, the potential use of local cooling of the cerebral cortex to inhibit seizure activity was examined in the canine and human brain undergoing active and passive surface cooling in an intraoperative setting. The authors provide interesting data indicating that the human cortex can be cooled with simple devices such as a cooling grid that could be used to control intractable epilepsy.
A case report on the use of therapeutic hypothermia in cardiac arrest due to amitriptyline and venlafaxine intoxication is also presented. These agents are widely used as antidepressants in the treatment of depression and have been shown to have significant cardiotoxicity as well as being used in suicide attempts. This case report suggests that mild hypothermia is safe, even in the case of intoxication of a drug known to cause serious cardiac conduction disturbances.
Finally, the Arctic Challenge includes several important questions raised in the area of therapeutic hypothermia and temperature management. One discussion concerns the use of venous thromboembolism prophylaxis procedures during the cooling phase to avoid potential complications including platelet dysfunction or alterations in clotting enzymes. Another topic concerns the use of CT to predict poor outcomes in survival of cardiac arrest and its use in determining when to discontinue hypothermic treatment. Individual patient outcomes are also described, which indicate responses to hypothermia that may have not been seen previously. The potential risk of bleeding, even when patients are cooled to 33°C, is also brought up in this issue of the Journal. Together these timely questions and responses by leaders in the field continue to provide useful information for treating physicians, nurses, and other care providers.
We hope the readers continue to enjoy the Journal and all of the information that is provided in each new issue. If you have any questions regarding the submission of an original article, special state-of-the-art review, or letter to the editor, please contact me directly. Again, I thank the reviewers for providing expert opinions on submitted publications as well as the authors for submitting timely and important articles.