Lifeguards who oversee open waters, such as oceans and lakes, may be able to deliver CPR effectively in a moving inflatable boat, according to a small study in Spain.
Surf-lifeguards provided the best cardiopulmonary resuscitation (CPR) on land but also delivered good-quality CPR on a small rescue boat, supporting the idea of starting CPR as soon as possible in real-life scenarios, researchers say.
"In cases of off-shore drowning, lifeguards should start CPR immediately and continue along the time required to reach the shore," said study author Cristian Abelairas-Gomez of the University of Santiago de Compostela.
More research is focusing on out-of-hospital CPR in recent years, particularly lifeguards' performance, he told Reuters Health by email. The European Resuscitation Council Guidelines put emphasis on open-water resuscitation in 2015, and experts are now investigating how different rescue scenarios affect CPR, he said.
The research team created an experimental simulation with 10 lifeguards on the Spanish island of Tenerife. The lifeguards were asked to perform two-minute CPR on training mannequins in four scenarios: onshore, on a floating boat, on a boat traveling at 5 knots and on a boat traveling at 10 knots. Each lifeguard had at least five years of experience, but none had on-boat CPR experience.
In all scenarios, the quality of CPR was measured by the number and depth of compressions and the degree of chest rise when breaths were administered to the mannequin. In all cases, the lifeguards' scores surpassed the CPR "success threshold" of 70 percent. However, the quality of CPR did decrease as boat speed increased. In particular, the boat's movement affected chest compression depth during CPR.
"Until more research is conducted, there may be a trade-off between quality of resuscitation during transport versus rapidly getting a victim to dry land," said Stephen Langendorfer of Bowling Green State University in Ohio who wasn't involved in the study.
"Since even highly-skilled professional lifeguards performed worse as speed increased, one could expect less well-skilled lifeguards to perhaps perform below the (CPR success) threshold," he told Reuters Health by email.
Worldwide, more than 370,000 deaths are due to drowning each year, representing 0.7 percent of all unintentional injury deaths, according to the World Health Organization. In the United States, drowning is the leading cause of injury-related death among children ages 1 to 4, according to the Centers for Disease Control and Prevention.
"Drowning is such a big problem and not publicized. The numbers are often underestimated," said David Szpilman, medical director of SOBRASA, a drowning prevention group in Rio de Janeiro, Brazil, who also wasn't involved in the study.
"There are so many variables in drowning scenarios that we don't have a recipe to say exactly what to do next," he told Reuters Health. "This study shows that as soon as you can ventilate, the better."
The variables posed the biggest limitation in the study, the authors write in the Emergency Medicine Journal. Sea conditions, such as waves, wind speed, water temperature and distance to shore could result in different rescue scenarios.
During the tests in September 2015, conditions at Los Gigantes beach on the island's west coast, where the testing was done, were cloudy, with calm winds, calm waves and water temperatures in the high 60s.
"In real life, sea conditions may be harder and CPR quality could be affected," Abelairas-Gomez said. "For one of the first studies of CPR on a boat, we thought it was necessary to begin with calm conditions."
Future studies will focus on harsher sea conditions and chest compressions on a moving boat, he added. In the current study, compared to onshore quality, chest compression depth dropped 20 percent at 10 knots and CPR quality decreased by 13 percent. There was also a 7 percent drop from CPR quality on an adrift boat versus a boat traveling at 10 knots.
"Drowning can happen to anyone, including those who know how to swim and think they can't drown," Szpilman said. "People underestimate the danger, especially when they're used to calm swimming conditions in a pool."