(Clarifies impact of procedure in paragraph seven)
April 4 (Reuters) - Amid all the technology used in hospitals to keep critically ill people alive, doctors are looking at whether the low-tech step stool can make a difference in performing the life-saving move cardiopulmonary resuscitation, or CPR.
The process includes chest compressions that need to be deep enough to move blood out of the heart and towards the rest of the body. But when a rescuer is short and the victim is on a hospital bed it can be hard to get enough leverage to press down on the chest.
Researchers at the University of Chicago Medical Center looked at whether using sturdy step stools helped improve the quality of CPR.
They found that the step stool worked best if the rescuer was about 5 ft. 6 inches (167 cm) or shorter, Edelson and her colleagues reported in the journal Resuscitation.
The study involved 50 people at their hospital, all trained in CPR, who performed chest compressions on a mannequin. Each did two two-minute rounds while standing on the floor and two while on a 9-inch (23 cm) high step stool.
The mannequin was outfitted with a sensor that recorded the depth of chest compressions and other measures of CPR quality, including "recoil," which means letting up enough to allow the chest to recoil so the heart can fill back up with blood.
On average, the depth of the shorter group's chest compressions increased by about a centimeter - which is significant, Edelson said. It suggests that shorter rescuers "may get a big benefit" from using a step stool.
On the other hand, taller rescuers increased their compression depth by only two-tenths of a centimeter, and that seemed to be offset by too much "leaning" - meaning that it can be harder for tall rescuers to pull their weight back, allowing the chest to recoil.
"We were a little surprised by the unintended consequence of leaning," Edelson said.
The study was not large enough to set a height cutoff for using a step stool, but based on the results it seems "reasonable" for rescuers who are about 167 cm or shorter to use a stool.
Researchers do know that the depth of chest compressions makes a difference.
In cardiac arrest, the heart stops pumping blood to the rest of the body often because it goes into a chaotic quivering known as ventricular fibrillation. If that happens, CPR chest compressions can keep blood and oxygen flowing to the rest of the body, but the only way to get the heart pumping on its own again is with a defibrillator or with certain drugs.
In an earlier study, Edelson's team found that a half-centimeter increase in compression depth doubled the odds that an actual cardiac arrest victim's heart could then be successfully shocked back into a normal rhythm with a defibrillator.
But even with all efforts, cardiac arrest is often fatal. The survival rate of in-hospital cardiac arrest hovers around 17 percent. SOURCE: bit.ly/HbJm9D (Reporting from New York by Amy Norton at Reuters health; editing by Elaine Lies and Bob Tourtellotte)