Conditions downrange leave troops susceptible to kidney stones
Walking to the latrines, Spc. Jonathan Grizzard ignored the back pain that had awoken him early.
He was about to start his day as an ambulance driver and cook at Bagram air base in Afghanistan, and this was no time for cramps. But the sharp pain overcame him and he fell to the floor. Lying near the bathroom stalls, he waited for his comrades to find him.
"It felt like having knives stuck into my kidneys," he said. "The pain was so intense I cried."
Grizzard succumbed to a common ailment for servicemembers in Iraq and Afghanistan: kidney stones. A 2008 study, which looked at the benefits of using medication to treat servicemembers with kidney stones, shows a steady increase in military personnel evacuated for stones from both Iraq and Afghanistan between 2004 and 2007. And the Air Force Theater Hospital at Balad — the main trauma center for soldiers wounded in Iraq — installed a laser that cuts the stones to a more manageable size so fewer troops, those with less severe cases, would have to be airlifted to Landstuhl Regional Medical Center in Germany.
Most doctors suspect dehydration is the cause of kidney stones for troops downrange, especially those wearing heavy gear in hot climates. One soldier, who needed to be airlifted because he could not pass the stones in theater, said his doctor thought his stones were caused by high calcium content in the bottled water downrange. Grizzard said he also heard rumors that the stones were linked to a higher mineral concentration in the bottled water — he was drinking up to eight bottles a day — in Afghanistan.
So is it dehydration, excessive hydration with minerals, or something else?
What causes stones?
Dr. Michael McDonald, a urologist at Landstuhl, said he has never heard the bottled-water theory, nor has he seen data to suggest it. And Dr. (Lt. Cmdr.) Sean Stroup, who is researching kidney stones in military personnel, pointed to a U.S. study showing that people who drank "hard" or "mineralized" tap water were not more likely to develop kidney stones than those who drank "soft" water with fewer minerals.
"What you drink does end up in the urine. It could be one component," Stroup said from the University of California, San Diego, where he is completing a fellowship in urology. But stones are likely caused by a confluence of factors, he said, including "genetics, excessive heat, not drinking enough water and high-calorie MREs (Meals, Ready to Eat)."
Both doctors suspect that dehydration is contributing to kidney stones in troops downrange, along with troops’ diets, which are high in protein and sodium.
When people are dehydrated, their urine becomes too concentrated, which allows stones to form, McDonald said. He sees about three to five patients a week with stones.
"There is no formal analysis to suggest the incidence of stones is higher in the military," McDonald said. "But I suspect it might be higher."
Drink deep, drink often
Kidney stones are formed from crystals within the urine. Most stones pass naturally, but when they grow to be larger than 5 millimeters, they can get wedged in ureters, tubes that carry urine to the bladder. When this happens, the jagged stones put pressure on the ureters and kidneys, which can cause sharp pain in the lower abdomen, back and groin.
"Some women say (the pain is) more severe than labor pains," McDonald said.
Medication, such as alpha blockers, can help patients pass kidney stones, and Stroup’s research suggests that it is twice as effective as regular therapy. But when medication fails, stones must be surgically removed. In surgery, the stones are sliced up with a laser, after which they can pass.
"Most people who have surgery return to theater," McDonald said. "We can get them back in four to five days."
The best way to prevent kidney stones is by staying hydrated, and the best way for troops to tell if they are drinking enough water is by the color of their urine, which should be clear to pale yellow.
"It’s an easy way to assess if you’re adequately hydrated," McDonald said.
Orange juice and lemon juice mixtures can also add a kidney stone inhibitor — citrate — to the urine.
"Dilution is the solution," Stroup said. "The risk of stones goes down in people who make 2 liters of urine per day."
Not an easy thing to do, McDonald said.
"You are going to have to train yourself to drink," he said. "It’s more than you’re going to want to drink."
Unfortunately, any soldier who has had kidney stones is likely to get them again. Half might have a reoccurrence within five years, McDonald said. Grizzard had already rid himself of about seven or eight stones, with one more to go.
"I’m going to have to deal with this forever," said Grizzard. "It sucks."