The Correct Technique and the Benefits of Utilizing CPR

It is 0300 hours and you and your company have not had a single call all night… suddenly, the tones drop. You are dispatched to an unknown aged subject not conscious and not breathing. Dispatch is working on getting the caller to start CPR and you and your company are responding to the scene. On arrival, the engine company establishes command and five paramedics and one EMT begin to work. One medic is working on getting intravenous access, while the other is getting the patient hooked up to the monitor. The EMT is doing chest compressions while an additional paramedic is working on securing the airway and the other medic is drawing up meds once the IV is established. The captain takes the caller into a different room and begins to get a history of the event if it was witnessed and a history on the patient. A cardiac arrest is one of the most active calls any emergency medical service will go on. During a cardiac arrest or full arrest, the heart stops pumping, and blood does not circulate to the peripheries of the body and that is why the initiation of chest compressions (or CPR) is so important. Also, because the patient is not breathing, we secure the airway with supraglottic airway adjuncts such as the Ambu® King LTS-D™ or an advanced airway device such as an endotracheal tube. But there is one small device that can be readily used and requires no set up time. Also, the piece of equipment does not get in anyone’s way and is very easy to use. This device is called an impedance threshold device (ITD) also known as a ResQPOD®. The use of an ITD has since increased in prehospital settings where many studies have been taken to prove the beneficial factors of utilizing this device during CPR.

Physiology of CPR and the Role of an ITD

Cardiopulmonary Resuscitation is used with patients in cardiac arrest. CPR is used with the goal of circulating the blood from the heart to the body through chest compressions and allowing return of the blood back into the heart by recoil. When the chest is decompressed, there is a decrease in intrathoracic pressure which results in the return of venous blood to the heart. When this recoil happens, a ‘vacuum’ is created and the patient beings to passively inspirate air. The ITD is designed to interfere with the passive inspiration during CPR. The ITD is “a disposable, plastic, cylindrical shaped device containing a silicon diaphragm which works as a one-way valve that can be attached to the endotracheal tube, laryngeal mask airway, or bag valve mask in line with the airway circuit” (CITATION HERE). The intrathoracic pressure of the patient becomes higher than that of the atmospheric pressure which causes the one way or unidirectional valve of the ITD to open and flow air freely out of the lungs. During recoil of the chest, the pressure-like mentioned before- falls below the atmospheric pressure and causes the valve to close. The closure of this valve prevents the air previously exhaled from re-entering the lungs and causing negative pressure in the chest cavity. The ITD d

Function

ZOLL, a company whose primary focus is to improve the outcomes in critical incidents, created the ResQPOD® designed specifically for cardiac arrests. The purpose behind their design is to allow for a greater preload and cardiac output during each compression. This is achieved when air is forced out through the threshold during compression, which mimics a heart contraction, forcing blood to the extremities and peripheries of the body. Thus, during recoil or decompression of the chest, the threshold device valve closes off not allowing air to be drawn back in. This then, in terms, creates a ‘vacuum’ inside the body that draws blood back to the heart. The purpose behind this allows for greater filling of the heart which in return allows for a greater preload for the next compression which results in a better cardiac output. The threshold valve on the device does not hinder a rescuer’s attempt at ventilating a patient while using a bag valve mask. But instead the bottom of the device was made to fit the connector at the top of a supraglottic airway adjuncts. The opening on top of the device allows for the connection of the bag valve mask. On the top of the device there is also a blue slide, and this is to turn the device on and off. When that slide is turned on, the device lights up with a red indicator lights and the purpose of the lights are to remind the rescuer who was put in charge of ventilation to ventilate the patient. The lights are programmed to blink every six seconds giving us a rate of ten breaths per minute. But if the slide is turned off, the device is still fully functional and still allows for the patient to be ventilated. To further people’s understanding on how this device works, YouTube has a video to help people visualize the purpose and utilization of this device. Shortly after this device was introduced by ZOLL, external studies came out and research was formed on the device. Most of the research done was to test the device just by itself. Additional research was done testing the device and its performance alongside another device called the Lucas CPR Device.

Research

In an article written by the American Heart Association also known as the AHA (2018), written by Guillaume Debaty, Paul Pepe, Demetris Yannopoulos, Nicolas Segal, Keith G Lurie, and Johanna C Moore, talks about research conducted using pigs and the idea that the positioning of the head in the heads up position (HUP for short) decreased internal cranial pressure due to the fact the blood had to be pumped uphill which would then result in better coronary perfusion. The test was conducted while using Lund University Cardiac Arrest System also known as LUCAS. For those who do not know LUCAS was implemented to perform high quality CPR all the time due to it being a piston driven device that runs off a single battery and air. The device has 2 different modes of CPR the 30:2 ratio or continuous CPR, and with this device in place it frees up a rescuer and allows them to perform other tasks. With constant high-quality CPR from LUCAS and an advanced airway established and ITD placed, it was found to have worked the best while the head was at a thirty-degree angle. The LUCAS and ITD at a zero-degree angle resulted in a lower beneficial outcome than just the LUCAS alone at a thirty-degree angle (Debaty, et al.,2018).

Contraindications

For every device, medication or ways of treatment for the patient there are a set of indications, but there is also a set of contraindications. During my time in the field at my place of employment, I only knew of one contraindication for this device, and that was if the patient got a return of spontaneous circulation. If that was the case for the patient, we immediately had to take the device off the patient.