Rolling Back the Fog of War

SURVEILLANCE AND MONITORING EVOLVE

Medical and scientific knowledge both arise from war and influence it. Recognition of the danger of sepsis and importance of public health measures halved the death rate from infection between the American Civil War and World War I, although infectious disease remains challenging (see sidebar below). Antibiotics slashed the risk further. And continuing analysis of health problems in Gulf War veterans is revealing potential dangers in current conflicts.

Information technology distinguishes what we are learning from war today compared to yesterday. "When Vietnam ended, we hadn't entered the automated age yet, and in the Gulf War we were just into it. We were not prepared for the need to have automated baseline health data on all troops," says Engel. In 1991, with the world interconnecting, the obsolescence of paper military records suddenly loomed. "Before we go off to war we need to have ways to automate databases on the health experience of each serviceperson deployed and follow up after they return to see how their health changes. We had to develop and implement baseline and longitudinal health data collection in military troops," he adds. Major efforts are underway now in the United States and the United Kingdom.

Record keeping also applies to the environment, as evidenced by a disaster in the Gulf War, with air so foul that matching symptom to pollutant was nearly impossible. In Operation Iraqi Freedom, the darkness following the "shock-and-awe" attack echoed conditions in the first Gulf War, but with more building materials than burning oil. As the dust settled, particulates and sand emerged as the biggest threat to respiratory health, as in Afghanistan.² Yet the air quality problem in both places is eclipsed by contaminated food and water supplies and temperature extremes.

For tomorrow's soldier, information such as reported symptoms and environmental conditions will be wed to output from the US Army's Warfighter Physiological Status Monitoring (WPSM) system. This wearable, lightweight suite of sensors, currently being tested in a variety of settings, will send physiological data to commanders and medics, communicating danger instantaneously. Devices track skin and core temperature, heart and respiratory rate, sleep, cognitive state, hydration, body orientation, and wartime acoustics, such as bullet impact. "When we optimize the science, we will field-test it for user acceptance. If those assurances are good, we will go into the next generation of development. But it will still be several years" before it is ready for the battlefield, explains Christopher Joyce, technology transfer and marketing specialist at the US Army Research Institute of Environmental Medicine in Natick, Mass.

Data from the WPSM project are generating predictive models that will guide implementation.³ For example, hydration data for males and females are documented for mountain climbing, arctic field training, and reconnaissance and surveillance missions. Heart rate and temperature changes in response to heat come from studies at Fort Benning, Ga. A 58-day stint at Army Ranger School in the desert, mountains, and swamps of the southeast United States tracked effects of extreme sleep deprivation.

FOLLOWING PTSD

Careful monitoring can help identify soldiers at risk for posttraumatic stress disorder (PTSD), which manifests at least a month following a triggering event. Recognition of PTSD came gradually. "During the Civil War it was seen but didn't have a name, other than 'malingering.' Guys never came back to themselves after the war," says Freemon. Longer engagements made PTSD more common. "A soldier would be hunkered down in a trench, hearing explosions day after day, with little hope. After 30 days new guys would come in. But nobody put it together until after World War I," Freemon adds, when it was dubbed "battle shock." By World War II it had become "battle fatigue," then later "post-Vietnam syndrome" before PTSD.

Understanding PTSD means understanding its roots, and that's where biomonitoring may reveal the precipitating conditions. "Vietnam was a milestone. No nation had rigorously conducted an epidemiological survey of males and females in the theater," says Matthew Friedman, executive director of the National Center for PTSD and professor of psychiatry and pharmacology at Dartmouth Medical School. But scrutiny was delayed. "It was done in the mid-1980s, but the conflict raged in the 1960s and 1970s. For the first Gulf War, PTSD research began five years later," he adds.

Now researchers aren't waiting. The US military has already questioned 2,530 soldiers in Iraq and 3,671 in Afghanistan about PTSD symptoms pre- and postdeployment.⁴ The most telling finding, according to Friedman, is that only 23% to 40% of those affected sought help, fearing stigmatization. Since in the past symptoms typically peaked two years postengagement, current figures may be an underestimate.

QUESTIONS ABOUT INFERTILITY

Few questions of fertility surrounded the return of WWII veterans, who promptly seeded a baby boom. But in the wake of the Vietnam War, anecdotal reports of a link between exposures and infertility contradicted conclusions from the National Academy of Sciences. "Since 1975 I've seen hundreds of patients who thought they were infertile because of exposures in Vietnam, either to Agent Orange or sustained trauma, stepping on a mine, or an illness," relates Cappy Rothman, medical director of the California Cryobank in Los Angeles. And so in 1990 and 1991, Rothman offered soldiers discounted sperm storage. "Not many guys availed themselves of the offer," he recalls.

But this year, announcement of a discount brought hundreds of requests, and prompted other cryobanks to follow. The reasons: fear of chemical and biological weapons and a link, after all, between infertility and exposures in the Gulf.⁵

Noreen Maconochie, senior lecturer in epidemiology at the London School of Hygiene and Tropical Medicine, and colleagues queried 10,465 Gulf War veterans trying to conceive and 7,376 matched controls in the military but not the Gulf.³ Results revealed more infertility and delayed conceptions for the vets. "We collected data on a number of self-reported exposures, including petrochemicals, pesticides, depleted uranium, as well as information on multiple vaccinations and pyridostigmine bromide, an anti-nerve gas agent," says Maconochie. In the future, biomonitoring data teamed with information from particulate monitoring devices and biosensors for biological weapons will pinpoint threats to fertility.

ENVIRONMENTAL EXTREMES

Soldiers in Iraq describe the punishing heat; those in Afghanistan, the treacherous and frigid mountains. US Army researchers at the Natick facility are listening. "We are trying to develop a body of scientific knowledge so we have a basis for medical and operational guidelines in environmental extremes," says Michael Sawka, chief of the thermal, mountain, and medicine division. For example, effects of extreme temperature on ion-channel functioning are being assessed in human cortical neurons and in mini-swine. Research using hypobaric chambers identifies susceptibility to mountain sickness.

Modern research into adaptation to extreme environments began at the Harvard Fatigue Laboratory in 1927. "After World War I we realized there were military problems, such as working in high-altitude aircraft or in extreme hot and cold, and we needed experts. After World War II it was discontinued," explains Sawka. The field, which had morphed into exercise physiology, relocated to university laboratories and the Department of Defense. But it was a stretch. "A soldier fighting is not as simple a situation as an athlete running a marathon. The athlete is in good condition and knows the outcome. The soldier is exposed to the environment not knowing for how long, with minimal food and water. Soldiers suffer tremendous sleep deprivation, fear, hard work, and exposure to heat and/or cold," he adds.

The WPSM project is proceeding with these extremes in mind. A "sleep watch, for example, tracks wrist movements that foretell stage of awareness. A swallowed 3-ounce, jellybean-shaped pill continuously transmits core body temperature readings, courtesy of the space program. And the WPSM recently added to its evolving ensemble the respiratory component of VivoMetrics' LifeShirt System technology, which is already used in exercise physiology studies.

"It weighs 8 ounces, is machine washable, and feels like Lycra," says Elizabeth Gravatte, director of marketing. Embedded wires detect heart rate, blood oxygen saturation, blood pressure, carbon dioxide level, and coughing.

Just as WWII-era findings found their way to athletics and health care, so too will the fruits of biomonitoring in the battlefield yield valuable information on physiology under stress, even if it seems as if a future soldier won't be able to belch without setting off alerts miles away. But the incoming data may make the combat theater a safer place. Sums up Friedman, "Knowing what to do provides a better buffer against the debilitating effects of traumatic exposures."

Ricki Lewis (rlewis@the-scientist.com)