Clinical Study of the LRS ThermoSuit™ System in Post Arrest Patients With Intravenous Infusion of Magnesium Sulfate

• Time from collapse to a core temperature < 34.0°C [ Time Frame: Approximately 30 to 180 minutes ] [ Designated as safety issue: No ]
• Percentage of time of the maintenance phase where the patient core temperature is between 32.0 and 34.0°C. [ Time Frame: Approximately 12 hours after initial cooling ] [ Designated as safety issue: No ]
• Incidence of shivering during cooling and maintenance of hypothermia [ Time Frame: Approximately 12 hours after cooling ] [ Designated as safety issue: No ]
• Duration of maintenance of hypothermia without supplemental cooling [ Time Frame: Approximately 12 hours after cooling ] [ Designated as safety issue: No ]
• Total number of days in ICU [ Time Frame: Generally less than 30 days ] [ Designated as safety issue: No ]
• Neurologic and physical status [ Time Frame: At discharge, 30 +/- 7 days, and 6 months +/- 15 days after initial treatment ] [ Designated as safety issue: Yes ]
• Adverse events, serious adverse events, device-related adverse events [ Time Frame: From enrollment through 6-month follow-up ] [ Designated as safety issue: Yes ]
• Blood pressure and ECGs [ Time Frame: Through hospital stay ] [ Designated as safety issue: Yes ]
• Serum chemistry parameters (standard chemistry panel) [ Time Frame: Through hospital stay ] [ Designated as safety issue: Yes ]
• Hematology parameters [ Time Frame: Through hospital stay ] [ Designated as safety issue: Yes ]
• Survival [ Time Frame: To 24 hours, hospital discharge, and 30 days ] [ Designated as safety issue: Yes ]
• Rate of infection (respiratory, skin, and invasive access sites) and rate of sepsis [ Time Frame: During hospital stay ] [ Designated as safety issue: Yes ]

This study will involve the use of therapeutic hypothermia. This prospective cohort pilot study will evaluate the clinical performance of a new device, the ThermoSuit™ System, to achieve therapeutic hypothermia in comatose patients following resuscitation from cardiac arrest, and the impact of the vasodilator, magnesium sulfate, on cooling performance and hemodynamics in these patients. The study hypothesis is that magnesium sulfate will significantly increase the rate of cooling.

This study will involve the use of therapeutic hypothermia, an accepted medical treatment recommended for comatose post resuscitation patients by the International Liaison Committee on Resuscitation (ILCOR), the American Heart Association (AHA), and the European Resuscitation Council. This prospective cohort pilot study will evaluate the clinical performance of a new device, the ThermoSuit™ System, to achieve therapeutic hypothermia in comatose patients following resuscitation from cardiac arrest, and the impact of the vasodilator, magnesium sulfate, on cooling performance and hemodynamics in these patients. 14 patients will be prospectively randomized to receive either magnesium sulfate or normal saline (placebo) in this study.

• Death, Sudden, Cardiac
• Coma

• Device: Cooling with ThermoSuit with Magnesium Sulfate Infusion
  Cooling with LRS ThermoSuit within 15 minutes of intravenous Magnesium Sulfate infusion (30 mg/kg, added to 100 ml normal NaCl solution, given over 15 min).
• Device: Cooling with ThermoSuit with Normal Saline Infusion
  Cooling with LRS ThermoSuit within 15 minutes of normal saline infusion (100 ml of normal NaCl solution, given over 15 min).

• Experimental: 1
  Comatose post-resuscitation patients cooled with ThermoSuit and treated with intravenous magnesium sulfate (30 mg per kg IV over 15 min).
  Intervention: Device: Cooling with ThermoSuit with Magnesium Sulfate Infusion
• Active Comparator: 2
  Comatose post-resuscitation patients cooled with ThermoSuit and treated with intravenous normal saline.
  Intervention: Device: Cooling with ThermoSuit with Normal Saline Infusion

Inclusion Criteria:

• Cardiac arrest prior to or during hospital admission, with restoration/return of spontaneous circulation (ROSC).
• Estimated or known age > 18 years.
• Intubation, ventilation and placement of esophageal temperature probe.
• Persistent neurologic dysfunction i.e. comatose upon enrollment [GCS ≤ 8].

Exclusion Criteria:

• Height greater than 188 cm.
• Elbow-to-elbow width greater than 60 cm (as measured above the supine patient).
• Core temperature less than 35°C after ROSC (as measured in the esophagus).
• Comatose state before the cardiac arrest due to the administration of drugs that depress the central nervous system.
• Known pregnancy.
• Known terminal illness that preceded the arrest.
• Known enrollment in another study of a device, drug, or biologic.
• Major trauma or other co-morbidity requiring urgent surgery.
• > 4 hours since return of spontaneous circulation.
• Severe coagulopathy (with active bleeding).
• Hemodynamic instability despite vasopressors (SBP < 90 mmHg or MAP < 60 mmHg for > 30 minutes after ROSC and before enrollment).
• Bradycardia (HR<60/min)
• Allergy against MgSO4
• AV-block
• Myasthenia gravis
• Known terminal renal insufficiency (creatinine-clearance < 20ml/min)
• Severe myocardial dysfunction (EF<25%)
• Chronic digitalis therapy