Effectiveness of the impedance threshold device in improving CPR survival outcomes

Abstract

BACKGROUND Objectives: Despite the establishment of cardiopulmonary resuscitation (CPR) more than 50 years ago, survival benefits following sudden cardiac arrest, still remains low (Abella, et al., 2005). It is suggested that augmenting the intrathoracic negative pressures through the application of the inspiratory impedance threshold device (ITD) could improve haemodynamic and resuscitation outcomes. However, uncertainty remains on the clinical impact of this novice device. As a deduction, this literature review intends to evaluate such proposition, through the PICO question: “In adult patients with non-traumatic out-ofhospital cardiac arrest, is CPR with augmented negative pressure (through an impedance threshold device, ITD), more effective than conventional CPR, in increasing survival rates with favourable neurologic function?” METHODS Eligibility Criteria: Predominantly, English-language studies published in peer-reviewed journals (2005 onwards) were included. However, only literature that studied adult patients with non-traumatic out-of-hospital cardiac arrest and singular use of the ITD were ultimately embodied. Appraising Literature: In light to appraise any methodological bias, two assessment tools were employed. Namely, Critical Appraisal Skills Program (CASP) tools, and Caldwell et al., (2011)’s framework. RESULTS Included Studies: Two systematic-reviews involving meta-analysis and three randomised controlled trials were included and appraised. Description of Effect: Skewed and non-conclusive results with respects to the ITD’s efficacy in improving CPR outcomes were observed. DISCUSSION Interpretation: Despite small physiological trials in both animal and human models have proposed that the ITD is capable in augmenting haemodynamic properties during CPR, this dissertation did not identify a survival advantage from its use. However, initial data suggests that the overall effect could shift in favour of the ITD, when combined with active-compression-decompression-CPR. This calls for further research and development, in light to bridge literature gaps, improve resuscitation quality, and the benefits that coincide with it.