The downward push of Earth’s gravity naturally causes blood to settle in the lower areas of the human body, and occasionally, with a quick movement — such as standing up from a chair — the body is not able to adjust fast enough to deliver an adequate supply of blood to the upper parts of the body and the brain. This sudden, temporary drop in blood pressure is what causes brief feelings of lightheadedness upon standing. In essence, when the heart pumps blood to different parts of the body, it is working against the physical phenomenon of gravity in its efforts to send blood up to the brain.
In more cases than not, the body is able to make the necessary adjustments to ensure proper bloodflow and pressure to the brain, but when the disorientation lasts a long time and/or becomes chronic, individuals may have a condition called orthostatic intolerance. Symptoms range from occasional fainting, blurry vision, and pain or discomfort in the head and the neck, to tiredness, weakness, and a lack of concentration.
The condition is a prominent concern for NASA, since astronauts have to readjust to the gravitational environment of Earth after spending days in the weightlessness of space. NASA’s Exploration Systems Mission Directorate has found that roughly 20 percent of astronauts coming off of short-duration space flights experience difficulty maintaining proper blood pressure when moving from lying down to either sitting or standing during the first few days back on Earth. The difficulties are even more severe for astronauts coming off of long-duration missions.
Cardiovascular experts at NASA have found that the blood that normally settles in the lower regions of the body is instead pulled to the upper body in the microgravity environment of space. Blood volume is subsequently reduced as some cardiovascular reflexes are no longer being used, and less blood flows to the legs. Additionally, the muscles weaken, especially in the lower portion of the body, because they are not working (contracting) as hard as they usually do. And when astronauts return to Earth’s gravity, more blood returns to the legs. Since there is a lower volume of blood, the flow that is supposed to be traveling to the brain can be insufficient. That is when orthostatic intolerance can set in.
NASA has conducted and sponsored a wealth of studies to counter the effects of orthostatic intolerance, especially since the condition could prevent an astronaut from exiting a landed spacecraft in the event of an emergency. At Kennedy Space Center in Florida, a collaborative research effort with the U.S. Army and private industry has yielded an important application for a new, non-invasive medical device called ResQPOD that is now available for astronauts returning from space. In helping to reacquaint the astronauts with the feeling of gravity, ResQPOD quickly and effectively increases the circulation of blood flow to the brain. This device is also available to the public as a means to enhance circulation for breathing patients suffering from orthostatic intolerance and for non-breathing patients suffering cardiac arrest or other high-risk clinical conditions attributed to low blood pressure.
Advanced Circulatory Systems (ACS) of Minneapolis, MN collaborated with Kennedy and the U.S. Army Institute of Surgical Research for more than five years to develop ResQPOD. Their studies demonstrated that ResQPOD offers a significant improvement in cardiac output and bloodflow to the brain, and in preventing shock in the event of considerable blood loss, when compared to conventional resuscitation.
In 2006, ResQPOD was added to the list of medical equipment that is available for returning astronaut crews.
How it Works
Manufactured commercially by Advanced Circulatory Systems and distributed by Sylmar, California-based Tri-anim Health Services, the ResQPOD circulatory enhancer improves upon the standard of care for patients with a variety of clinical conditions associated with low bloodflow. ACS’s primary commercial focus is on non-breathing patients who can benefit from enhanced circulation, such as those experiencing cardiac arrest. ResQPOD is an American Heart Association-rated Class IIa impedance threshold device, meaning that it is the highest recommended “adjunct” in the association’s latest guidelines for CPR.
The device is about the size of a fist and can be affixed to either a facemask or an endotracheal breathing tube during CPR. It enhances the intrathoracic vacuum that forms in the chest during the chest recoil phase of CPR by temporarily sealing off the airway between breaths and preventing unnecessary air from entering the chest (timing-assist lights on the device will aid the rescuer in ventilating the patient at a proper rate). The vacuum that is created pulls blood back to the heart, doubling the amount of blood that is pulled back by conventional mouth-to-mouth/chest compression CPR, according to clinical studies, which also show that bloodflow to the brain is increased by 50 percent. In sustaining proper bloodflow to the heart and to the brain, ResQPOD increases the likelihood of survival and decreases the likelihood of neurological disorders.
Where it Stands
ResQPOD is being used by emergency medical technicians across the country. In some cities, it has reportedly increased the number of cardiac arrest patients delivered alive to the hospital by as much as 50 percent. In its secondary commercial applications, ACS is offering ResQPOD to improve circulation in patients suffering from orthostatic intolerance and general low blood pressure. These secondary uses also apply to individuals who undergo dialysis treatments and may experience a drop in blood pressure, as well as those who go into shock after severe blood loss.
Outside of the traditional hospital setting, the company is investigating the beneficial impact ResQPOD could have on wounded soldiers in the battlefield who may have lost a great deal of blood and are in danger of going into shock. ACS is also harnessing the physiological principles discovered during its research collaboration with NASA to develop another promising technology: an intrathoracic pressure regulator for patients requiring ventilation assistance because they are too sick to breathe on their own.
For more information on the ResQPOD system, visit http://info.hotims.com/22930-153.