Preface

This book is meant to look at the evidence behind the application of Therapeutic Hypothermia on patients with injury to the Central Nervous System, including both brain and spinal cord. Central nervous system injury includes ischemia reperfusion after cardiac arrest or asphyxiation, traumatic brain injury, acute ischemic stroke, hemorrhagic stroke, refractory intracranial hypertension, cerebral edema in acute liver failure, subarachnoid hemorrhage, as well as spinal cord injury (SCI). In the minutes to hours following injury, cascades of destructive events and pathophysiologic processes begin at the cellular level. These result in further neuronal injury and are termed the secondary injury. Cellular mechanisms of secondary injury include all of the following: apoptosis, mitochondrial dysfunction, excitotoxicity, disruption in ATP metabolism, disruption in calcium homeostasis, increase in inflammatory mediators and cells, free radical formation, DNA damage, blood-brain barrier disruption, brain glucose utilization disruption, microcirculatory dysfunction and microvascular thrombosis. All of these processes in the brain and spinal cord are temperature dependent; they are all stimulated by fever, and can all be mitigated or blocked by mild to moderate hypothermia. As a result, there has recently been extensive interest in studying the application of Therapeutic Hypothermia (TH) to brain and spinal cord injured patients. This book will discuss the mechanisms by which therapeutic hypothermia can mitigate the pathophysiologies responsible for secondary brain injury, as well as the available evidence for the use of therapeutic hypothermia in multiple neurologic injuries (stated above). Recent studies have indicated that TH with a reduction of body core temperature (T) to 32 - 34 °C for 12 to 24 hours has improved survival and neurologic outcome in comatose out-of-hospital cardiac arrest patients. In this patient population, the evidence for TH is overwhelming leading to major international associations giving it a class I recommendation. However, the evidence for its application to patients with other forms of brain injury stated above and SCI is less overwhelming and still in progress. This book will describe the clinical human evidence behind therapeutic hypothermia for all of the above mentioned brain and spinal cord injuries, as well as the basic and animal studies that led to its clinical applications. This book will also describe how to apply hypothermia to patients with brain injury in the intensive care unit (ICU), methods of cooling and technologies used to induce and maintain therapeutic hypothermia, protocol development for hospitals and ICUs, as well as timing, depth, duration, and management of side-effects.

#### XII Preface

Neuroprognostication of patients with brain injury and SCI is also significantly affected by the application of therapeutic hypothermia. This book will also describe how hypothermia can influence the ability to prognosticate these injured patients, as well as describe the current evidence to help clinicians offer the family the best and most honest discussion on prognosis of their loved ones. We will also describe how TH influences the metabolism of the most commonly used drugs in the ICU, and how this effect is also linked to prognostication of these patients with brain and spinal cord injury. It will also provide grounds for future directions in the application of and research with therapeutic hypothermia.

#### **Farid Sadaka, MD**

Clinical Associate Professor Critical Care Medicine/ NeuroCritical Care Medical Director, Trauma and Neuro ICU Mercy Hospital St Louis/ St. Louis University St. Louis, USA **Therapeutic Hypothermia-General** 

**Chapter 1** 

© 2013 Lakshmanan et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2013 Lakshmanan et al., licensee InTech. This is a paper distributed under the terms of the Creative Commons

**Therapeutic Hypothermia:** 

**and Treatment Strategies** 

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/55022

**1. Introduction** 

Romans have used it.

30degree C).

prevention

aneurysm surgery

abdominal aortic aneurysm

Rekha Lakshmanan, Farid Sadaka and Ashok Palagiri

Hypothermia is any body temperature below 36 degree C.

Cardiopulmonary resuscitation Class-I Traumatic brain injury (ICP CONTROL) Class I Traumatic brain injury ( outcome) Class IIa Stroke Class-III Fever in patients with neurological injury Class IIb

Subarachnoid hemorrhage- vasospasm

Intraoperative hypothermia for thoraco-

Intraoperative hypothermia for intracerebral

**Figure 1.** Current indications for induced therapeutic hypothermia

**Adverse Events, Recognition, Prevention** 

Therapeutic hypothermia has been around for centuries, ancient Egyptians, Greeks, and

Therapeutic Hypothermia is induced hypothermia and can be mild (34-35.9 degree C), moderate (32-33.9 degree C), moderately deep (30.1-31.9 degree C) or deep (less than

Class-IV

Class-IIb

Class-III

**Chapter 1** 
