Hypothermia Manual Dr. Edward Omron MD, MPH, FCCP
Upon reviewing this manual, the healthcare worker should be able to understand the goals of the hypothermia protocol as outlined under goals section. They should also be able to implement and practice the hypothermic intervention in the hospital to meet these goals. Introduction
This manual is designed to outline all aspects related to the hypothermic protocol including: 1) indications of its use 2) inclusion/exclusion criteria 3) procedures and policies related to the protocol 4) technical complications of using hypothermia 5) management and monitoring 6) evidence and support of its use 7) criteria met to receive privileges in the hospital
Healthcare workers should review the manual in its entirety and acquire the skills and comfort in its practice. Please call the Director of Critical Care for further questions.
Concept/Goal of Hypothermia Improving outcomes from sudden cardiac death is a healthcare dilemma and only 5-30% survive to discharge. Mild resuscitative therapeutic hypothermia is an intervention which may improve neurologic outcomes in survivors of cardiac arrest.
Mechanism of Hypothermia/How it Works <ul><li>Reduction in cerebral metabolism </li></ul><ul><li>Reduction in vascular permeability and cerebral edema </li></ul><ul><li>Reduction in immune response and inflammation </li></ul>
Steps of Technical Procedure Policy How to cool: Different cooling techniques are combined for optimal patient cooling. Induction cooling is accomplished initially with ice-chilled crystalloid infusion and ice packs followed by a cooling blanket system. Timing and Depth of Cooling: Cooling should be initiated after return of spontaneous circulation. The 2005 AHA ACLS guidelines recommend patients to 32-34 Celsius for 12-24 hours.
Cooling Monitoring: A bladder probe is recommended with the cooling protocol. Shivering which prevents achieving the target temperature is treated aggressively with Demerol and paralytics. Mechanically ventilated patients are deeply sedated. Steps of Technical Procedure Policy (continued) Re-warming: Therapeutic hypothermia is completed after 18 hours of cooling with subsequent rewarming to desired temperature.
Inclusion/Exclusion Criteria Inclusion Criteria: <ul><li>Adult Unconscious patients who have experienced a witnessed cardiac arrest of a presumed cardiac origin < 15 minutes from the patient’s collapse to the first attempt at resuscitation with no more than 60 minutes from collapse to restoration of spontaneous circulation. </li></ul><ul><li>OR </li></ul><ul><li>Unconscious adult patients who have experienced an acute ischemic stroke with Glascow Coma Score (GCS) < 8 and deemed appropriate for hypothermia or normothermia protocols by the attending physician, intensivist, or neurologist. </li></ul><ul><li>The patient must have endotrachial intubation with mechanical ventilation and a blood pressure that can be maintained at least 90 mm hg systolic either spontaneously or with fluids and pressors. </li></ul><ul><li>Thrombolytic therapy does not preclude the use of mild resuscitation hypothermia. </li></ul><ul><li>Percutaneous Coronary Intervention (PCI) does not preclude the use of mild resuscitative hypothermia. </li></ul>
Exclusion Criteria: <ul><li>age < 18 years old </li></ul><ul><li>pregnancy </li></ul><ul><li>coma before the arrest </li></ul><ul><li>response to verbal commands after return of spontaneous circulation </li></ul><ul><li>cardiogenic shock (systolic pressure < 90 mm Hg despite vasopressor tx) </li></ul><ul><li>clinical signs of pulmonary edema </li></ul><ul><li>rectal, esophageal, or bladder temperature < 30 degrees Celsius on initial measurement </li></ul><ul><li>patients with diagnosed terminal illnesses </li></ul><ul><li>unfavorable overall cerebral performance status before arrest </li></ul><ul><li>severe coagulopathy </li></ul><ul><li>another reason for comatose (drug overdose) </li></ul><ul><li>known hypersensitivity to any of the routinely used drugs in the protocol </li></ul>
Complications Complications of Cooling: <ul><li>induction hypothermia causes many physiological changes. Awareness of these changes is key to successful implementation. </li></ul><ul><li>hypovolemia (hypothermia induced dieresis) </li></ul><ul><li>coagulopathy (impaired coagulation cascade and thrombocytopenia </li></ul><ul><li>electrolyte disorders (hypothermia induced dieresis, K+, Mg++, Ca++) </li></ul><ul><li>insulin resistance </li></ul><ul><li>changes in drugs effects and metabolism (altered clearance of fentanyl, midazolam, and atracurium) </li></ul>
Complications of Re- warming: <ul><li>worsening cerebral edema </li></ul><ul><li>further changes in electrolyte abnormalities (especially hyperkalemia) </li></ul><ul><li>hyperthermia (induced fever) </li></ul>Complications (continued)
Polderman KH (2004) Application of Therapeutic Hypothermia in the Intensive Care Unit. Intensive Care Med 30:757-769 Polderman KH (2004) Application of Therapeutic Hypothermia in the ICU: opportunities and pitfalls of a promising treatment modality (Part I). Intensive Care Med 30:556-575 Also see attached articles for further review/education Evidence/Support for Implementation of Hypothermia