Jan. 11, 2011 -- As Americans brace themselves for storm number two of the season, doctors remind all the devoted shovelers out there to have "great respect" for the dangers of winter conditions, both during and after a storm.
And just in time for the nor'easter, a study published in the American Journal of Emergency Medicine has revealed the most common snow-related injuries. The research also showed that snow shoveling can raise heart rates above the recommended limits after only two minutes of digging.
Scientists from the Research Institute at Nationwide Children's Hospital and Ohio State University College of Medicine analyzed data from US emergency departments over a 17-year period.
Around 195,100 Americans were treated in emergency rooms for snow shoveling-related incidences from 1990 to 2006. Approximately two-thirds of the injured patients were males, and children 18 and younger made up about 15 percent of the cases.
Cardiac problems accounted for almost seven percent of the cases, and made up all of the 1647 deaths in the study.
Doctors say slips and falls are the most common injuries caused by snow and ice, but heart dangers can create the largest health hazard to come with a snowfall.
"The risk of heart attack is increased by the combination of heavy, upper body exertion and cold weather encountered while shoveling snow," said Dr. William Abraham, director of the division of cardiovascular medicine at Ohio State University. "People, especially those at risk for coronary heart disease, should avoid heavy exertion in cold weather conditions."
That's because people can be unaware of their own heart blockages, and even an insignificant heart condition can suddenly become significant in certain weather, said Dr. Randy Zusman, director of the hypertension program at the Massachusetts General Hospital Heart Center.
There are two major points that can put people at risk for heart problems when it's cold.
"For one, most people don't realize that when their hands get cold, it causes blood vessels in the heart to constrict and reduce the blood supply to their heart," said Zusman. "I always tell people to invest in the best pair of gloves they can afford and remember to be all buttoned up before going outside."
So, if a blood vessel is 20 percent to 30 percent blocked, it can become up to 70 percent to 80 percent blocked due to the constricting walls in the cold weather conditions, said Zusman.
And once the shovel comes out of the garage, things can often get much worse.
"People like shoveling snow. They complain about it, but they're devoted to that snow shoveling," said Zusman.
And with that devotion can come two things: raised blood pressure and an accelerated heart rate.
"Lifting heavy snow is like heavy weight lifting," said Zusman. "It puts a strain on the heart, and the blood pressure and heart rate go up in response to it."
Those With Heart Conditions Shouldn't Shovel
And if those levels increase too much in a person who has a pre-existing heart condition, it can lead to angina or even a heart attack.
Because of this, Zusman said that people with any sort of heart conditions should avoid shoveling all together.
"I can be rather unbending on this issue," Zusman continued.
Adelman said even those with healthy hearts should be ready for the winter exertion by staying in shape throughout the year. "That way, when a physical demand is placed on a person [like shoveling], they are ready to react," said Adelman.
He added that health people should take precautions. "People should dress very warmly when going outside so as not to expend energy keeping warm. … And if they notice that they are getting out of breath, they should slow their pace and rest."
Dr. Gabriel Wilson, associate medical director at St. Luke's-Roosevelt Hospital in New York, worked his emergency room shift until 3 a.m. Monday. He cared for three people who'd sustained wrist fractures, one person with an ankle fracture and two who had received blows to the head. Every injury stemmed from slips on ice and snow.
"These are the typical snow-related injuries, and the only thing one can do, other than being careful walking in the snow, is to wear padded gloves, jackets and hats, which may cushion the fall," said Wilson.
Dr. Richard Bradley, associate professor of emergency medicine and chief of EMS and disaster medicine at the University of Texas Medical School at Houston, reiterated the importance of keeping warm when temperatures plummet.
"The onset of hypothermia can be very difficult to detect," said Bradley. "We lose a lot of people every year from it, because people often don't realize they're becoming hypothermic."
Symptoms of hypothermia include constant shivering, clumsiness and confusion, drowsiness, a weak pulse and shallow breathing.
"As the hypothermia worsens, people realize even less that they're getting colder," said Bradley. "We see this a lot in people who are alone and don't have anyone to say, 'Hey, you don't look so good.'"
Dr. Hersch Leon Pachter, chairman of the department of surgery at New York University School of Medicine, said hypothermic patients who come into the emergency room are often homeless.
"A lot of people off the street come in with hypothermia," said Pachter. "They're sleeping outside and being exposed to the elements."
"At this time of year, especially when you're having fun, it's possible to get frostbite, which is actually the freezing of parts of the body," said Bradley. "Digits begin to lose sensation and turn white or waxy, and the worst thing you can do is warm them and freeze them again."
This tidbit might surprise even the most avid of winter athletes.
Bradley said that warming a frostbitten area, then subjecting it to the freezing cold again can cause ice crystals in the tissue, which only multiplies the damage done to the frostbitten skin. If people develop signs of frostbite while hiking or hunting, they should wait to re-warm the area until they are safely out of the elements.
Frostbitten skin turns white or gray-ish yellow and can feel itchy, tingling, hard or numb. Severe frostbitten skin turns black and can cause blistering and permanent damage in the effected area.
"The re-warming process can be quite painful." said Bradley, "So, if you have signs of frostbite, it's a good idea to go to the ER and have it treated in a controlled setting."
While on the Road, Leave the Moxie at Home
And, while it's one thing to be walking around in the winter wonderland, it's a whole different animal to be driving. If you're on the road, Pachter said it's particularly important not to become a victim of self-deception. Be cautious, no matter what kind of vehicle you're driving.
"You're not superman because you're in a souped-up SUV," said Pachter. "Some people have a lot of moxie when driving those SUVs. They think they can get in their four-wheel-drive car and go 60 miles an hour."
Pachter said it's that reckless driving that causes visits to the emergency room.
Dr. David Ross, an emergency medical physician in Colorado Springs, Colo., said that it's important to put warm clothing and supplies in the car so that, if the car does break down in the cold, the driver and passengers are prepared.
"Have great respect for the danger of blizzard snow conditions," said Ross. "Make sure to have emergency weather gear available for all occupants of the vehicle. This would include a heavy coat, sweater or fleece, hat, gloves, heavy socks and some sort of snow boots, as well as a working cell phone."
And doctors agreed that, when the weather is snowing on the parade, it's best to stay home. Traveling or shoveling the walkway simply is not worth the risk.
"Stay home," said Pachter. "And use a lot of common sense."