Impedance Threshold Devices for the usage during code blues. These devices are used with cardiac arrest patients of non-traumatic aetiology, and have been shown to improve the survivability of patients during CPR. Basically, they work by generating a negative pressure within the chest by resisting the re-expansion of the chest during the decompression phase of CPR. This negative pressure generated by the ITD cause an improvement venous return and then improves the cardiac output and coronary circulation. The ITD also lowers intercranial pressure also adding to improved cerebral perfusion.
ITDs can be inserted between bag and mask during CPR but we would prefer installing imbetween an ETT and bagger, as with the mask maintaining a tight seal throughout CPR is pivotal to the device’s success. The manufacturer has also applied a timing light mechanism (little red switch) to 10 bpm at inspiratory times of 1sec each. Spontaneous ventilation can occur with the device if -10 cmH2O efforts are generated. However at the time of return to spontaneous respirations the ITD should be removed from the circuit. If at all there are secretions within the ITD, take the bagger and flush the secretions out. If the secretions fail to clear the ITD needs to be discarded. Once the code is complete the ITD is then discarded – single use only.