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

Summary

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.

Conditions

• Cardiac Arrest

Interventions

OTHER

Standard Care

Triple-lumen central venous catheter inserted for pressure monitoring. All patients to receive 500-mL bolus of intravenous crystalloid every 30 minutes to achieve central venous pressure of 8 to 12 mm Hg; vasopressors if mean arterial pressure less than 65 mm Hg; and vasodilators if mean arterial pressure is 90 mm Hg or above. Initiation and maintenance of therapeutic hypothermia, target core temperature of below 34°C via standard external cooling techniques. Percutaneous coronary intervention performed as soon as feasible in patients with ST elevation or left bundle branch block on initial ECG. Serum biochemistry (including sodium, potassium, bicarbonate, glucose, calcium, phosphate, magnesium and lactate) monitored every 6 hours.

DEVICE

Low Volume Hemofiltration

Patients will receive isovolemic HF at a blood flow rate of 250 mL/min and ultrafiltration rate of 45 mL/kg/h for 48 hours. Initial replacement solution will be Prismasol BGK4/2.5. 3.1mg/dL phosphate (1.0 mmol/L) added to each bag. Replacement fluid adjusted as required based on chemistry values for sodium, potassium, bicarbonate, glucose, calcium, phosphate, magnesium and lactate. Vascular access for HF will be via an 11.5-F, double-lumen venous catheter in a central vein. The hemofiltrate will be replaced by fluid infused before (i.e. predilution) and after (i.e. postdilution) the filter. A fixed ratio of 80:20 predilution:postdilution used. HF 1400 (i.e. polysulfone -based membrane) filters used throughout study. Hemofilter changed every 6 h after initiation of HF, and as required.

DEVICE

High Volume Hemofiltration

Patients allocated to high volume HF will receive HF at 250 mL/h blood flow rate and 90 mL/kg/h ultrafiltration rate for 48 hours. All other care will be identical to that provided in the low volume HF group. Vascular access for HF will be via an 11.5-F, double-lumen venous catheter in a central vein. The hemofiltrate will be replaced by fluid infused into the bloodstream before (i.e. predilution) and after (i.e. postdilution) the filter. A fixed ratio of 80:20 predilution:postdilution will be used. HF 1400 (i.e. polysulfone -based membrane) filters will be used throughout the study. The hemofilter will be changed every 6 h after initiation of HF, and otherwise as required.

Sponsors & Collaborators

• University of Washington

  lead OTHER

Principal Investigators

• Graham Nichol, MD · University of Washington

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2012-01-31

Primary Completion

2013-11-30

Completion

2014-06-30

Countries

• United States

Study Locations