Another close call with hyponatremia 
By Michelle Hillman 
Tuesday, April 22, 2003 
 
BOSTON -- Katherine Guevara, an experienced marathoner who 
didn't follow doctors' recommendations, said if there had been a bowl of 
pretzels at the finish line, she would have eaten them to recoup the salt 
she  lost by drinking two cups of water at each station along the 26-mile 
route.
 
Guevara, who finished in 3 hours and 38 minutes, was the first case of
hyponatremia in the Boston Marathon medical tent yesterday -- a 
condition that killed charity runner Cynthia Lucero of Waltham last year. 
Three other cases followed Guevara, and one of them was hospitalized. 
Hyponatremia is caused by overloading the body with fluids, which dilute 
sodium levels in the blood. 
 
"She's a real case," said Dr. Arthur Siegel. "A woman who could've been a 
Cynthia Lucero this year. It proves how important the testing is." Siegel, a 
physician at McLean Hospital in Belmont, has  been studying blood samples
from cases like Lucero's to determine what other factors cause hyponatremia, 
or water intoxication. 
 
Most runners aren't aware of the dangers of hyponatremia, but Guevara, 26, 
of  Virginia knew she needed salt because she felt dizzy and disorientated. 
Her blood test showed she was right, and she was immediately given salty, 
hot broth to drink by Siegel. "She's a classic case," he said. "She's a 
full-blown case."
 
Hyponatremia is common in petite women, and charity runners who are on 
the course for five or six hours and drink continuously during the race. 
The condition is also common among ultra-marathoners, who run as many 
as 50 to 100 miles, and tri-athletes, who compete for long periods of time. 
These athletes are encouraged to take sports drinks to replace electrolytes. 
 
But Guevara, who is an ultra-marathoner, said she doesn't like Gatorade, and 
loaded up on three liters of water before the race and drank throughout. She
still entered the tent in a treatable condition. Lucero's death -- only the second 
in Marathon history and the first from hyponatremia -- has changed the way 
medical officials treat runners. 
 
Each registered Marathoner and charity runner received information about how 
to properly hydrate themselves. They were told to weigh themselves on practice 
runs before Marathon day -- if they gained weight they were drinking too much; 
if they lost weight, they needed more fluids. 
 
Guevara did not follow these directions and actually had gained 2 pounds on 
the course, coming into the tent at 118 pounds. Runners can suffer from 
hyponatremia hours after running the Marathon, said Siegel. If blood sodium 
levels indicate runners are hyponatremic, they should not drink any fluids until 
they urinate, he said, so the condition won't worsen. Once urination resumes, 
runners should drink no more than 6 to 8 ounces of fluids per hour for the next 
six hours. 
 
If they are nauseous or vomit or faint, they should immediately visit an emergency 
room. Runners can confuse the condition with dehydration, which has similar 
symptoms, and often continue drinking, worsening their conditions. In severe 
cases, hyponatremia causes seizures, coma and death as a result of brain swelling. 
 
Lucero drank 16 ounces of fluid five minutes before she collapsed, Siegel said. 
Lucero collapsed at mile 22 and later died at Brigham & Women's Hospital. 
 
Siegel believes an antidiuretic hormone that prevents the kidney from secreting 
fluid is also at play when runners develop hyponatremia. In addition to testing 
blood sodium levels before administering IV fluids, Siegel was conducting a pilot 
study yesterday using a test called an osmolality. 
 
The test measures how  concentrated or diluted a runner's body fluids are and 
if there is more of the suspected antidiuretic hormone present. If the test is 
shown to work -- connecting hyponatremics with elevated levels of the hormone, 
called arginine vasopressin -- it could become a new standard at marathons across 
the country. The hormone is made in the brain and is in charge of regulating water 
excretion by the kidney.
 
Siegel was in charge yesterday of determining who had dangerous sodium
levels and delivering test results to physicians who tailor the amount of fluids 
given to runners based on the results. Terry Shirey, director of scientific affairs 
at Nova Biomedical of Waltham, said for the last four years the company has 
provided equipment at the medical tent to test blood sodium levels. "The idea 
is to get a sodium result on the runner's blood as fast as we can after they've 
crossed the finish line," Shirey said. 
 
Joan Casey, medical coordinator for the Boston Athletic Association, said a
couple of years ago -- before Lucero's death -- Guevara might have been
treated for dehydration with more fluids.