Effect of Hydration on Whole Blood Viscosity in Firefighters Pilot Study1
Ralph E. Holsworth Jr, DO; Young I. Cho, PhD; Joseph Weidman, BS, PharmDc2
This study was designed to measure the effect of heat stress, physical exertion, and dehydration on firefighters’ whole blood viscosity (WBV) levels and to identify the best means to test for and minimize the risk of dehydration for firefighters. The study found that 30 minutes of stringent, mock firefighting conditions led to as much as a 17.2 percent increase in WBV measurements, and concluded: “WBV measurements were better determinants of hydration states than hemotocrit or hemoglobin and should be performed to monitor the cardiovascular health of at-risk firefighters.”
The pilot study also indicated that firefighters’ WBV measurements should be used to monitor the cardiovascular health of at-risk firefighters.
The pilot study, commissioned by Essentia Water and designed by Ralph E. Holsworth Jr, DO, confirmed that dehydration has a profound negative effect on blood viscosity, a measurement of the thickness and stickiness of an individual’s blood. In this study, rehydration with Essentia Water was an effective means of significantly improving WBV levels that were depressed during the high-stress activity and very nearly restored the body to its pre-exercise state. Note: The manufacturer describes Essentia Water as a Super Hydrating Water whose proprietary process results in an electrolyte-enhanced water with optimum alkalinity and an ideal pH of 9.5. (Note: Our pH is the measure of how acidic or alkaline we are. A pH of 0 is completely acidic, and a pH of 14 completely alkaline. A pH of 7 is neutral. Blood must always be slightly alkaline, with a pH of 7.35 to 7.45.–http://www.webmd.com/diet/features/alkaline-diets-what-to-know.)
Dr. Holsworth explains that heat stress, physical exertion, and fluid losses can decrease cardiac output and put the firefighter at risk of a heart attack. “Blood viscosity,” he adds, “is a critical parameter that determines the amount of friction against the blood vessels, indicates how hard the heart has to pump, and how much oxygen is delivered to the body’s organs and tissues.”
The pilot study covered nine healthy, nonsmoking firefighters from the Fire Training Division of the Tukwila (WA) Fire Department (TFD). Measurements were performed over a two-week period prior to the drill to establish normal WBV and complete blood count measurements for each participant. On the day of the study, the eight male and one female participants, wearing a self-contained breathing apparatus and carrying 70-lb. packs up and down stairs for two 30-minute sessions of mock firefighting in a building with a live fire, were subjected to a stringent mock fire drill. Less than an hour after the exercise, upon rehydration with the 9.5pH water, the firefighters’ blood tests showed they had been very nearly restored to pretest baseline hydration levels.
Tukwila (WA) Fire Department members participating in the pilot study. (Photos courtesy of Essentia Water)
TFD Chief Nick Olivas explained in a phone conversation that he had heard about Essentia alkaline water from a friend and “tried it.” Coincidentally, he said he noticed that the migraine headaches he frequently suffered had let up. Thinking that maybe this had something to do with the change in his body’s pH, he started drinking the water at home and also ordered it for his fire department. “So, when I had the chance to participate in the company’s firefighter study, which was designed to examine the effect of dehydration on firefighter’s WBV, I was on board,” he recalls. “I’m all for anything we can do to learn more about how to measure and mitigate risks from dehydration.” Olivas says he hopes that “a much larger fire department will sign up to participate in a follow-up study Essentia is planning to further evaluate the benefits of WBV testing and to test absorption and rehydration rates using different types of water.”
Ken Uptain, Essentia Water’s president and CEO says the follow-up study will involve a greater number of firefighters. Departments interested in participating in the study should contact him at kuptain@essentiawater.com.
Among other findings of the pilot study were the following:
- Blood viscosity, much like blood pressure, rises and falls with each cardiac cycle.
- To get a meaningful test, a systolic (high-shear) and a diastolic (low-shear) blood viscosity measurement are needed. Systolic blood viscosity is affected by hematocrit and plasma and is known to be highly affected by hydration status.
- Hematocrit (Hct), which measures the number of red blood cells (Hb), is an important determinant of WBV levels.
- The changes in the WBV from predrill to postdrill were much great than for those the Hct and Hb (9.5 percent and 17.2 percent, respectively).
- Before the test began, the participants had a mean baseline
- WBV of 39.0 (low-shear) and 105.5 (high-shear). In the first blood draw after the test, WBV numbers jumped to 42.7 and 123.6, respectively. After rehydration, average WBV levels dropped back to near normal at 38.8 (low-shear) and 109.8 (high-shear).
- It is importance to stay hydrated throughout exercise whether you’re a firefighter, a cyclist, an avid cross-fit participant, or an active adult.
Dr. Holsworth explains the potential significance of this study and WBV testing as follows:
Q. Rehydration is already a big part of firefighter rehabilitation. What does this study tell us that we didn’t already know?
A. Firefighter WBVs post-exercise exceeded critical values (i.e., values consistent with heart attacks and strokes). The rehydration of firefighters with Essentia restored WBVs to safe levels, close to initial pre-exercise levels. The one firefighter using filtered water did not restore his WBVs to lower levels.
Q. What are the benefits of conducting WBV testing to monitor at-risk firefighters, and how could this be implemented?
A. WBV is more sensitive to predicting a heart attack and/or stroke than convenient vital signs; blood pressure, heart rate, respiratory rate, and pulse oximetry. In reviewing the data, the paramedics sent a firefighter back into the exercise with critically high WBV, placing him at risk for a heart attack, stroke, or hypertensive crisis.
Q. What would the cost be for a firehouse or department to implement WBV testing?
When, where, and how would you recommend it be done?
A. Currently, it is a lab-based diagnostic, and price would be determined by quantity. I would encourage medical review panels to test WBV at least on an annual basis with other annual lab work, complete blood count, and so on. If the firefighter has known cardiac risk factors, then quarterly testing would be advised. Several commercial laboratories provide the testing to the public.
Q. Do you have any data on the differences between WBV levels after rehydration with Essentia water vs. another type of water? If so, are you able to share these numbers?
A. Yes, the firefighter who drank filtered water (vs. Essentia Water) in the pilot study did not restore his hydration to the same level that was accomplished by Essentia. Other research using bioimpedance analysis indicates pH 9.5 or higher alkaline water can rehydrate intracellular greater than 25 percent when compared with filtered bottled water. As noted above, future studies will evaluate for rehydration differences between Essentia and other bottled waters.
Q. What should fire departments and firefighters glean from this study?
A. There are more than 300 independent cardiac risk factors. WBV is the only common denominator to determining a functional assessment of a firefighter’s risk of a cardiovascular event in the line of duty. I have been in conference with a board member of the American Heart Association who believes WBV will be the next “vital sign” when we can develop it into a “real-time” test. When detected early, “hyperviscosity syndrome” is very treatable through efficient hydration, donating blood, and nutritional and lifestyle changes. One of four patients has a genetic predisposition to developing an inadvertent blood clot, which many times is identified by an elevated WBV.
Footnotes
1 The results were published in the July/August 2013 issue of Alternative Therapies magazine.
2 Ralph E. Holsworth Jr, DO, is a staff medical physician at Southeast Colorado Hospital, Springfeld. Young I. Cho, PhD, is a professor of mechanical engineering and mechanics at Drexel University, Philadelphia, Pennsylvania. Joseph Weidman, BS, is a PharmD candidate at Tomas Jefferson University, Philadelphia, Pennsylvania.
MARY JANE DITTMAR is senior associate editor of Fire Engineering and conference manager of FDIC. Before joining the magazine in January 1991, she served as editor of a trade magazine in the health/nutrition market and held various positions in the educational and medical advertising fields. She has a bachelor’s degree in English/journalism and a master’s degree in communication arts.
