Washington Study of Hemofiltration After Out-of-Hospital Cardiac Arrest

The purpose of this study is to assess the feasibility of hemofiltration in patients resuscitated from cardiac arrest. Cardiac arrest is the loss of mechanical activity of the heart including the loss of detectable pulse, or spontaneous breathing. When heart function is restored, the cells of the body release molecules into the blood that cause inflammation, unstable blood pressure, organ dysfunction and death. Hemofiltration is a technique of washing the blood to remove fluid and molecules from it. Hemofiltration is a proven therapy for renal failure, but is considered investigational for treatment after resuscitation from cardiac arrest. Some experts believe that hemofiltration after heart function is restored can remove inflammation from the blood, maintain blood pressure and organ function. Others believe that intravenous fluid and medications are sufficient to maintain blood pressure and organ function. Since the inflammation that occurs after restoration of heart function lasts, the investigators continue hemofiltration for up to 48 hours. Whether hemofiltration or intravenous fluids and medications is better is not known. The investigators are checking if they can wash the blood of patients resuscitated from cardiac arrest before the investigators can begin a large randomized trial to test whether hemofiltration improves their outcome.

The investigators are testing this by randomly allocating patients resuscitated from cardiac arrest to receive low volume hemofiltration, high volume hemofiltration, or intravenous fluids and medications alone. The null hypotheses are that less than 80% of eligible patients will be enrolled, and that less than 80% of enrolled patients will undergo low-volume or high-volume hemofiltration (HF) for at least 80% of 48 hours.

Patients resuscitated from out-of-hospital cardiac arrest will be randomly allocated to one of three groups; Standard of care: Initiate standard of post-resuscitative care including a triple lumen catheter to monitor central venous pressure, core temperature maintenance between 32C and 34C if unconscious. Fluids, inotropes, vasopressors, vasodilators to maintain hemodynamics.

Low-volume Hemofiltration for 48 hours: Initiate standard of post-resuscitative care including a triple lumen catheter to monitor central venous pressure, core temperature maintenance between 32C and 34C if unconscious. Hemofiltration x 48 hours via a 11.5F double lumen venous catheter, blood flow 250mL/h, ultrafiltration 45mL/kg/h. Fluids, inotropes, vasopressors, vasodilators to maintain hemodynamics.

High-volume Hemofiltration for 48 hours: Initiate standard of post-resuscitative care including a triple lumen catheter to monitor central venous pressure, core temperature maintenance between 32C and 34C if unconscious. Hemofiltration x 48 hours via 11.5F double lumen venous catheter, blood flow 250 mL/h, ultrafiltration 90 mL/kg/h. Fluids, inotropes, vasopressors, vasodilators to maintain hemodynamics.

30 patients will be enrolled.

Eligibility Criteria:
Inclusion Criteria:

* adults
* restoration of spontaneous circulation sustained to hospital arrival after OOHCA with any first recorded rhythm
* aged \>=65 years
* less than 1 h from call to 911 until emergency department arrival
* less than 6 h from arrival until randomization
* informed consent provided by legally-authorized representative

Exclusion Criteria:

* do not attempt resuscitation orders; known end-stage terminal illness pre-arrest; major pre-arrest neurological dysfunction; another reason to be comatose (e.g. drug overdose)
* chronic steroid use
* non-English speaking LAR
* previous enrollment in the trial
* blunt, penetrating, or burn-related injury; exsanguination; drowning, electrocution or strangulation
* known pregnancy
* known prisoner
* weight \> 100 kg
* persistent (i.e. 30 minutes) SBP\< 80 mmHg despite pressors; refractory ventricular arrhythmias; severe bradycardia without a pacemaker
* thrombocytopenia (i.e. \< 50,000/microL) or coagulopathy (i.e. INR \> 1.5) or inferior vena cava filter in situ
* known cirrhosis
* serum ionized calcium \< 2.2 mmol/L serum lactate \> 6 mmol/L
* obeying verbal commands