Impedance threshold device does not improve outcomes of CPR

January 01, 0001

Impedance threshold device does not improve outcomes of CPR

The impedance threshold device (ITD) is designed to enhance venous return and cardiac output during cardiopulmonary resuscitation (CPR) by increasing the degree of negative intrathoracic pressure. Previous studies have suggested that the use of an ITD during CPR may improve survival rates after cardiac arrest. These US and Canadian investigators compared the use of an active ITD with that of a sham ITD. Patients, investigators, study coordinators, and all care providers were unaware of the treatment assignments. The primary outcome was survival to hospital discharge with satisfactory function (i.e., a score of 3 or less on the modified Rankin scale, which ranges from 0 to 6, with higher scores indicating greater disability).

They found: "Of 8718 patients included in the analysis, 4345 were randomly assigned to treatment with a sham ITD and 4373 to treatment with an active device. A total of 260 patients (6.0%) in the sham-ITD group and 254 patients (5.8%) in the active-ITD group met the primary outcome (risk difference adjusted for sequential monitoring, -0.1 percentage points, NS). There were also no significant differences in the secondary outcomes, including rates of return of spontaneous circulation on arrival at the emergency department, survival to hospital admission, and survival to hospital discharge."

The authors concluded: "Use of the ITD did not significantly improve survival with satisfactory function among patients with out-of- hospital cardiac arrest receiving standard CPR."

This is useful evidence about what not to introduce into practice.

For the full abstract, click here.

N Engl J Med 365:798-806, 1 September 2011 © 2011 to the Massachusetts Medical Society
A Trial of an Impedance Threshold Device in Out-of-Hospital Cardiac Arrest. Tom P. Aufderheide, Graham Nichol, Thomas D. Rea, et al. Correspondence to Dr. Augderheide: [email protected]

Category: K. Circulatory. Keywords: cardiopulmonary resuscitation, CPR, impedance threshold device, survival, randomized controlled trial, journal watch.
Synopsis edited by Dr Linda French, Toledo, Ohio. Posted on Global Family Doctor 13 September 2009

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.