Over the past decade use of an impedance threshold device (ITD) has been shown in significantly increase vital organ perfusion pressures and survival rates in animals and humans. The device works by enhancing venous b...Over the past decade use of an impedance threshold device (ITD) has been shown in significantly increase vital organ perfusion pressures and survival rates in animals and humans. The device works by enhancing venous blood flow back to the heart during the decompression phase of cardiopulmonary resuscitation (CPR) , thereby priming the pump for the subsequent compression phase. The purpose of this article is to summarize the recent advances with this new ITD technology. The ITD increases circulation during CPR. It also contains ventilating timing lights to help prevent hyperventilation as excessive ventilation during CPR has recently been shown to be a common and a deadly error during the performance of CPR. At the time of this report there have been three clinical trials with the ITD during standard CPR (sCPR) and four clinical randomized trials with the combination of the ITD and active compression decompression (ACD) CPR. In patients in cardiac arrest receiving sCPR, use of the ITD increased systolic blood pressure from around 60 mm Hg to 90 mm Hg. Survival rates were found to increase in patients with out-of-hospital cardiac arrest by nearly 50% , regardless of the initial presenting heart rhythm. In patients with pulseless electrical activity (PEA) at any time during the cardiac arrest, which accounts for about 50% of all patients in cardiac arrest undergoing CPR, use of the ITD with sCPR increased 24 hour survival rates by nearly 250% , from 11% to 27%. In another study, patients presenting initially with either asystole or PEA had a 32% chance of resuscitation and survival to hospital admission with the ITD versus only 16% without the ITD. Studies with the combination of the ITD and ACD CPR have shown a similar benefit with the ITD. One trial in patients with an out of hospital cardiac arrest demonstrated that systemic blood pressures and coronary perfusion pressures were markedly higher when using the ITD compared with controls. A second clinical trial demonstrated that the ITD was effective with both a face mask and an endotracheal tube. A third randomized clinical trial (n=210 patients) demonstrated that 24-hour survival rates for out of hospital cardiac arrest were >65% higher with the ITD and ACD CPR versus sCPR (P<0.01). Patients with a witnessed cardiac arrest who present with ventricular fibrillation in that study had>2-fold greater chance for surviving to at least 24 hours with the ITD (58%) versus controls (23%). Neurological function, as measured by an Overall Performance score, trended higher in patients with a witnessed arrest and ITD plus ACD CPR in this clinical trial compared with manual CPR （P<0.07). A fourth study comparing ITD plus ACD CPR versus sham ITD and ACD CPR in a randomized double-blinded clinical trial of patients with out of hospital cardiac arrest showed that 24-hour survival rates were 32% in the active ITD group versus 22% in the sham group （P<0.05). Again, brain function was better in the survivors treated with the ITD:6/10 survivors had normal brain function with the active ITD versus 1/8 with the sham ITD. Based upon these cumulative findings, use of the ITD provides superior vital organ blood flow and results in significantly higher short term survival rates compared with sCPR alone or ACD CPR. Use of the ITD technology optimizes perfusion of the heart and brain during CPR and results in the highest reported survival rates of any CPR device technology. Use of the ITD should be encouraged with either sCPR, or with ACD CPR in systems with adequate number of trained rescuer personnel.展开更多
文摘Over the past decade use of an impedance threshold device (ITD) has been shown in significantly increase vital organ perfusion pressures and survival rates in animals and humans. The device works by enhancing venous blood flow back to the heart during the decompression phase of cardiopulmonary resuscitation (CPR) , thereby priming the pump for the subsequent compression phase. The purpose of this article is to summarize the recent advances with this new ITD technology. The ITD increases circulation during CPR. It also contains ventilating timing lights to help prevent hyperventilation as excessive ventilation during CPR has recently been shown to be a common and a deadly error during the performance of CPR. At the time of this report there have been three clinical trials with the ITD during standard CPR (sCPR) and four clinical randomized trials with the combination of the ITD and active compression decompression (ACD) CPR. In patients in cardiac arrest receiving sCPR, use of the ITD increased systolic blood pressure from around 60 mm Hg to 90 mm Hg. Survival rates were found to increase in patients with out-of-hospital cardiac arrest by nearly 50% , regardless of the initial presenting heart rhythm. In patients with pulseless electrical activity (PEA) at any time during the cardiac arrest, which accounts for about 50% of all patients in cardiac arrest undergoing CPR, use of the ITD with sCPR increased 24 hour survival rates by nearly 250% , from 11% to 27%. In another study, patients presenting initially with either asystole or PEA had a 32% chance of resuscitation and survival to hospital admission with the ITD versus only 16% without the ITD. Studies with the combination of the ITD and ACD CPR have shown a similar benefit with the ITD. One trial in patients with an out of hospital cardiac arrest demonstrated that systemic blood pressures and coronary perfusion pressures were markedly higher when using the ITD compared with controls. A second clinical trial demonstrated that the ITD was effective with both a face mask and an endotracheal tube. A third randomized clinical trial (n=210 patients) demonstrated that 24-hour survival rates for out of hospital cardiac arrest were >65% higher with the ITD and ACD CPR versus sCPR (P<0.01). Patients with a witnessed cardiac arrest who present with ventricular fibrillation in that study had>2-fold greater chance for surviving to at least 24 hours with the ITD (58%) versus controls (23%). Neurological function, as measured by an Overall Performance score, trended higher in patients with a witnessed arrest and ITD plus ACD CPR in this clinical trial compared with manual CPR （P<0.07). A fourth study comparing ITD plus ACD CPR versus sham ITD and ACD CPR in a randomized double-blinded clinical trial of patients with out of hospital cardiac arrest showed that 24-hour survival rates were 32% in the active ITD group versus 22% in the sham group （P<0.05). Again, brain function was better in the survivors treated with the ITD:6/10 survivors had normal brain function with the active ITD versus 1/8 with the sham ITD. Based upon these cumulative findings, use of the ITD provides superior vital organ blood flow and results in significantly higher short term survival rates compared with sCPR alone or ACD CPR. Use of the ITD technology optimizes perfusion of the heart and brain during CPR and results in the highest reported survival rates of any CPR device technology. Use of the ITD should be encouraged with either sCPR, or with ACD CPR in systems with adequate number of trained rescuer personnel.
