1. EMS Pearls on Hydration, Cooling and Recovery in Rehab
Mike McEvoy, PhD, NRP, RN, CCRN
EMS Coordinator – Saratoga County, NY
EMS Editor – Fire Engineering magazine

4. Disclosures I am on the speakers bureau for Masimo Corporation
I do not intend to discuss any unlabeled or unapproved uses of drugs or products

5. NFPA Rehab Standard Originally recommendation (2003)
Published as a Standard (2008)
Standard revised (2015)
2015 Edition

6. McEvoy’s Philosophy: Where’s the beef evidence? Rehab baggage
Firefighters are not children

7. NFPA 1584: 2015 Revisions Significant changes:
Member responsibilities added
Vital signs now required
Parameters defined locally
Data collection streamlined
Passive cooling now used initially
Beverages revised to match science
EMS required to release each member

8. HYDRATION
Firefighter rehab

9. No Changes
CALORIES
Nutrition education

10. Firefighter Health Calorie sources:
Carbohydrates
Proteins
Lipids (fats)
During high-stress states, virtually all calories are derived from carbohydrate sources.

11. HOW SCIENCE HAS EVOLVED
Big Changes
FLUID & ELECTROLYTE REPLACEMENT
HOW SCIENCE HAS EVOLVED

12. Firefighter Hydration
Monitoring hydration:
Firefighters can lose 32 ounces (1 Liter) of fluid in less than 20 minutes of strenuous firefighting.
Sweating will continue after the firefighter stops work.

13. Firefighter Hydration
The amount of fluid an exhausted, warm and dehydrated firefighter can take orally is about 32 ounces (1 liter) per hour.
This is due to a delayed gastric emptying time from an overloaded GI system.

14. Firefighter Hydration
Monitoring hydration:
Dehydration interferes with the body’s ability to maintain core temp.
Dehydration lessens strength and shortens endurance.
Dehydration causes nausea and vomiting making it difficult to orally hydrate.

15. Firefighter Hydration
Physical performance is intimately related to hydration.
1 – 2% reduction in body mass:
16% reduction in muscle strength
Loss of concentration
Lowered alertness
Feeling of tiredness
Headaches
Increased body or environmental temps:
Markedly greater reductions in physical and mental performance
185# FF = 84 kg
1 liter = 1 kg
Sweat 2 liters/hour
Loss = 2 kg/hour
= 2.4% body mass lost every hour

16. Firefighter Hydration
Firefighters are often dehydrated!
Studies
Smoke Diver schools
Training academies
etc…

17. Firefighter Hydration
Prehydration should be considered based upon expected activity and environmental factors.

18. Firefighter Hydration
Beverage science
Firefighters & athletes
Water
Sports drinks
Energy beverages
Caffeine

19. Water
Water is the best way to maintain hydration.

20. Water Water is the best way to maintain hydration.
Water is in food/beverages.
Typical diet contains 1 liter of water/day in food.

21. Water Water is the best way to maintain hydration.
Water is in food/beverages.
Typical diet contains 1+ liter of water/day in food.
Overemphasis on water in sports/public has increased incidence of hyponatremia.
“More is better” approach ill advised.

22. Water Water needs vary considerably between people.
“More is better” approach ill advised.
Water needs vary considerably between people.
FF can sweat 2 liters per hour.
Gastric emptying capacity is only 1 liter per hour.

23. Firefighter Rehabilitation
FF hydration:
Personnel should consume small quantities of fluid at one time (2-4 ounces) and do so frequently.
Increase the quantity of fluids as physical exertion increases.

24. Informal Rehab Requirements:
Fluids
Shelter
Place to remove PPE
Seating for members

25. Firefighter Hydration
Hyponatremia
Seriously low blood Na+ level.
Usually due to excessive water intake.
Can have other causes especially in athletes.
In events < 4 hours, nearly always due to overconsumption of water.
Signs and Symptoms
Swelling in the brain (AMS)
Nausea/vomiting
Seizures/coma
Death

26. Hydration and Prehydration
Firefighters are often dehydrated
Prehydrate for planned activities?
500 mL fluid (16 oz.) within 2 hours prior to event
Recommended in 2008 version NFPA 1584
May still be logical if hydration status unknown
Hydrate during events:
Water appropriate most of the time
Sports drinks after first hour of intense work or 3 hours total incident duration

27. Electrolytes? Electrolyte abnormalities are more common when:
Incidents > 3 hours.
Incidents where personnel are likely to be working for > 1 hour.
May need to replace electrolytes in addition to water in these situations.

28. 1584 Recommendation
If a firefighter is involved in intense physical activities for more than an hour, fluids with a 4%-8% carbohydrate solution should be considered (sports drinks).
6-8 ounces ( mL) should be consumed every 15 minutes.
The drinks should be cool and flavored as the firefighter will tend to consume more.

29. Sports Drinks Usually contain electrolytes and carbohydrates
Osmolarity (concentration) formulated for maximal absorption
Absorption limited by gastric emptying time (COH)
Dilution will extend gastric emptying time and lead to nausea / vomiting

30. Sports Drink Investigation
BMJ investigative report
1035 web pages (listed in magazine ads), 431 performance-enhancing claims on 104 different products
47.2% had references, none referred to systematic reviews (level 1 evidence)
84% judged at high risk of bias
Only 3 (of 74) studies judged to be high quality and low risk of bias
Heneghan C, Howick J, O’Neill B, Gill PJ, et al. The evidence underpinning sports performance products: a systematic assessment. BMJ Open 2012; 2:e doi: /bmjopen

31. Sports Drink Investigation
Conclusions: The current evidence is not of sufficient quality to inform the public about the benefits and harms of sports products. There is a need to improve the quality and reporting of research, a move towards using systematic review evidence to inform decisions.

32. Sports Drinks Bottled sports drinks are preferred – don’t dilute.
If using powdered sports drinks, mix according to the manufacturer’s recommendations.
Ideally, water and sports drinks should be available.

33. Sports Drink Ingredients Gatorade® Thirst Quencher
Sports Drinks
Sports Drink Ingredients
Ingredients
per 8 ounces
Accelorade®
Cytomax® ETD
Gatorade® Thirst Quencher
Gatorade® Endurance
Powerade®
Powerade® Advance
Powerade® Option
Sodium
120 mg
55 mg
110 mg
200 mg
53 mg
Chloride
90 mg
Potassium
30 mg
15 mg
32 mg
35 mg
Calcium
6 mg
Magnesium
3 mg
Carbohydrate
15 gm (6%)
13 gm (5%)
14 gm (6%)
17 gm (7%)
2 gm (<1%)
Caffeine
47 mg
Calories 80 50 64 66 10

34. Energy Drinks
Definition: “A type of beverage containing stimulant drugs (caffeine, and other ingredients such as taurine, ginseng, guarana) that is marketed as providing mental or physical stimulation.” Not to be confused with Sports Drinks

35. Energy Drinks Marketed as performance enhancers
Very clear association with arrhythmias, seizures, hospitalizations and deaths, particularly in younger individuals
Bad for firefighters at any time (on or off duty)

36. Caffeine Caffeine was banned in the 2008 edition of NFPA 1584.
Believed to promote dehydration from diuretic effect.
Multiple studies have proven this to be a myth!

37. Caffeine in Firefighters
Study: Low (< 300 mg) and high (> 600 mg) caffeine consumption in firefighters
Low ( mg)  urine output for 3 hours
But at 4 hours, total = to ff who drank equal amt. water
High  urine up to 41% above baseline
But, at 24 hours had no net effect on hydration status
Bottom Line: little to no evidence to suggest that low to moderate levels of caffeine consumption (< 300 mg or 3.1 mg/kg daily) alter hydration status at rest or during exercise.

38. Firefighter Hydration
Beverages, foods and substances to avoid:
Carbonated, high-fructose-content, and high sugar drinks (> 7% CHO solutions)
High fat and high protein foods
Alcohol within 8 hours
Excessive fluids
Tobacco
Creatine supplements
Ephedrine
Beverages exceeding 400 mg of caffeine per day
Energy drinks

39. Firefighter Hydration
Alcohol is a central nervous system depressant and a diuretic (causes water loss).
Alcohol consumption within 8 hours prior to strenuous firefighting can lead to early dehydration.

40. Hydration Assessment Thirst Controversial
Recent studies in competitive cyclists: one of the most reliable indices for optimizing hydration
Blunts with aging
In high sweat states, lags behind (“voluntary dehydration”)
Thirst is most certainly helpful in preventing overdrinking and underdrinking

41. Hydration Assessment
There are no practical means for precisely determining hydration status at an incident scene.
Assessment tools:
Orthostasis
Body weight measurement
Urine assessment
Saliva osmolarity

42. Hydration Assessment Conventional tools: Vital signs Dizziness
Headache
Dry skin
Tachycardia
In performance sports and firefighting, more likely related to environment and activity!

43. Hydration Assessment Body Weight: Good assessment of fluid loss.
Serial measurements required (for reliable baseline).
Not practical in rehab area.

44. Hydration Assessment Urine testing:
Color charts required (or machine).
Requires collection, measurement and disposal (biohazard).
Only accurate on first morning void.

46. Hydration Status Saliva osmolality
- Poor correlation on the fireground

47. + or Hydration Assessment
Evaluating all sports and firefighter studies:
Body Weight +
Urine assessment:
USG
Urine Color + or

48. Hydration Assessment Evaluating all sports and firefighter studies:
Body Weight +
Urine assessment:
USG
Urine Color
Nude weight on three consecutive mornings
First morning void:
Urine Specific Gravity
or Urine Color
If USG – or Color 1 – 3, then average nude weight = euhydrated weight

49. Fluid Replacement Change from baseline defines fluid volume loss.
> 2% loss = significant dehydration
Requires 1.5 L per kg (2.2 #) below baseline

50. Fluid Replacement
Consuming large volumes of fluid over short periods will  urine output
Thus urine is not a reliable tool for evaluating rehydration
500 mL aliquots over minutes is optimal

51. Fluid Replacement
Water, sports drinks, IV normal saline have no differences in effects on performance in heavy work scenarios.
Flavored powders and sports drinks  the appeal of fluids

52. Fluid Replacement
Members entering rehab should consume enough fluids to satisfy thirst.
If not thirsty, drink anyway.
Rehydration should continue post-incident as it may take more time and fluids than initially thought to restore proper hydration.

53. COOLING
Firefighter rehab

54. TEMPERATURE REGULATION
MEDICAL monitoring

55. Medical Monitoring Limited FF heat studies.
Regular heat related FF deaths, often in training.
FF temps continue to rise for 20 minutes regardless of cooling interventions.

56. Medical Monitoring
The core temperature is the temperature deep within the body (usually in a great vessel such as the pulmonary artery or vena cava).
The core temperature is a more accurate measure of body temperature.

57. Medical Monitoring
For healthy individuals with good blood flow, an oral temperature is usually an accurate reflection of the core temperature.

58. Medical Monitoring
For abnormal states (hypothermia, hyperthermia) blood flow through the body may be impaired rendering oral temperature readings unreliable and erroneous.
In these situations, a rectal reading is preferred.

59. Medical Monitoring Core body temperature assessment:
Pulmonary Artery (PA) Catheter temp
Esophageal
Urinary Bladder (UBT) – if making urine
Rectal

60. Medical Monitoring
Many departments use tympanic or oral thermometers to measure temperature
NL core temp °F ( °C)
Oral 1°F, tympanic 2°F less than core
Caution: devices may be offset

61. Medical Monitoring Temporal Artery Thermometer (TAT)
Offset to display core temp

62. Medical Monitoring Diaphoresis Temporal Artery Thermometer (TAT)
Offset to display core temp
Diaphoresis

63. And, this just in… “Peripheral Thermometers Lack Accuracy”
Ann Intern Med (Nov. 16, 2015)
Meta-analysis 75 studies (8682 patients, 21 countries)
Compared peripheral to central devices
Tympanic, temporal, axillary, oral vs. PAC, UBT, esophageal, rectal
Poor agreement in fever and hypothermia
If central not available, best options are electronic oral (adults) or tympanic (adults and children)

64. Medical Monitoring Temperature Concerns: Considerations:
Measurement error; accuracy
Interference from hydration, sweating, cooling, clothing, helmet, environment.
Considerations:
Touch is highly accurate and may suggest heat related illness
Never use a measured temp to exclude heat related illness!

65. Big Changes
COOLING
MEDICAL monitoring

66. Medical Monitoring Cooling can be accomplished two ways:
Passive cooling: Facilitating the body’s cooling mechanisms, such as removing clothing, moving the subject to a cooler environment, and removing the subject from direct sunlight.
Active cooling: Using external methods or devices (e.g., hand and forearm immersion, misting fan, cold towels) to reduce the elevated body temperature.

67. Medical Monitoring Passive Cooling:
Helmet, hood, gloves, SCBA, and coat should be removed and stowed prior to entering rehab.
Pants should be opened at the top (20% greater cooling)

68. Medical Monitoring
Passive cooling: move to a cooler area

69. Medical Monitoring
Members entering rehab should consume enough fluids to satisfy thirst.
Rehydration helps lower body temperature.
There is no risk to firefighters from consuming chilled fluids.
(your mother didn’t know what she was talking about)

70. Medical Monitoring
Active cooling is recommended when passive cooling is ineffective or signs/symptoms of heat stress are present.

71. Active Cooling:

72. Medical Monitoring Wet towels: As effective as forearm immersion.
Sometimes more practical and less expensive.

73. Medical Monitoring
Often, a combination of techniques is used on the fire ground to prevent heat stress.
Importantly, no one strategy (including an air conditioned room) is superior to any other cooling method.
Except…
Espinoza M, Contreras M. “Safety and performance implications of hydration, core body temperature, and post-incident rehabilitation.” Orange County Fire Authority (CA). December, 2007

74. Cold Towels…(preferred by FF)

76. Vests…

77. Medical Monitoring When entering rehab on warm days:
Remove protective clothing (including opening top of bunker pants)
Drink plenty of fluids
Cooling should be started as soon as possible:
Passive cooling initially
For severe conditions, switch to active cooling immediately.

78. RECOVERY
Firefighter rehab

79. Firefighter Rehabilitation
When should rehab commence?
(2015 version*) “Procedures shall be in place to ensure that rehab operations commence whenever emergency operations or training activities pose the risk of members exceeding a safe level of physical or mental endurance.”
* The 2008 version had similar language predicated by event duration of 1 hour OR

80. Firefighter Health
*-Excludes WTC FDNY Loss of 2001
Source: USFA/FEMA

81. Fireground Injuries

82. FF LODDs – Likely Culprits:
Medical condition
Fitness
Rehab

83. Firefighter Health
Firefighters must be medically cleared to participate in the rigors of firefighting.
NFPA 1582: Standard on Comprehensive Occupational Medical Program for Fire Departments gives guidance.

84. Firefighter Health
Firefighter fitness is an essential component of safety and essential for longevity on the job.
NFPA 1583: Standard on Health-Related Fitness Programs for Fire Department Members gives guidance.

85. NIOSH LODD Reports: Themes
Overweight
Unrecognized/untreated CV dz
Sole complaint: “tiredness”

86. NFPA 1584: 2015 Revisions Member: Use rehab Hydrate
Advise CO when performance affected
Awareness of others

87. Firefighter Rehabilitation
Rehab criteria:
Personnel shall be provided with rehab following use of:
A second 30 or 45-minute SCBA bottle.
A single 60-minute SCBA bottle.
Or 40 minutes of intense work without SCBA.
A supervisor (CO) shall be permitted to adjust time frames depending on work or environmental conditions.

88. Best Practices in Rehab
WORK-TO-REST RATIOS
Company officers know their crews. It is important for company officers to stop and periodically assess all crew members for the need to undergo rehab (at least every 45 minutes). In severe conditions, the assessment interval should be decreased accordingly.

89. Documentation
A rehab documentation report shall be created to include:
Unit number
Member name
Time in/out
Disposition
Medical monitoring records are part of the incident records.
Emergency care is documented on a PCR.

90. NFPA Sample Rehab Log

91. Rehab Tags:

92. REHAB MEDICAL DECISION-MAKING SCHEME
Medical Monitoring
INITIAL REHAB MEDICAL EVALUATION
Immediate transport to an emergency medical facility
Close monitoring and treatment in the rehab area
Release from rehab
REHAB MEDICAL DECISION-MAKING SCHEME

93. Can we determine when a FF is tired?

94. Can we asses recovery in rehab?

95. Hydration Assessment Conventional tools: Vital signs Dizziness
Headache
Dry skin
Tachycardia
In performance sports and firefighting, more likely related to environment and activity!

96. Value of Heart Rate? Simulated 10th floor high-rise fire (Virginia)
198 ff, rehab on 8th floor
HR means: 176 max, 149 entry rehab, 126 after 15” rehab (88% would not have been released from rehab under current recommendations)
Tremendous variability
Smith DL, Haller JM, Benedict R, Moore-Merrell L. Firefighter incident rehabilitation: interpreting heart rate responses. Prehosp Emerg Care. 2016; 20:28-36.

97. 12-lead in Rehab 12-lead Holter during live fire training evolutions
Conclusions: Fire suppression is associated with ST-segment changes among firefighters at low risk for cardiovascular disease (33%). These abnormalities continued into initial recovery even though cooling and rehydration were provided % of ff exceeded their maximum HR.
Al-Zaiti S, Rittenberger J, Reis SE, Hostler D. Electrocardiographic responses during fire suppression and recovery among experienced firefighters. J Occup Envir Med ; 57: 938–42.

98. Medical Monitoring EMS shall be available for eval/tx Minimum BLS
EMS shall evaluate members arriving at rehab for s/s suggestive of a health or safety concern

99. Medical Monitoring
On entry to rehab, EMS shall be alert for the following:
Chest pain
Dizziness
Shortness of breath
Weakness
Nausea
Headache
General complaints (cramps, aches and pains)
Symptoms of environmental stress (heat or cold)
Mental status changes
Behavioral changes
Changes in speech
Changes in gait (ataxia)
Abnormal vital signs (per departmental guidelines)

100. Medical Monitoring
The following vitals shall be obtained for all members entering rehab:
Temperature
Heart rate
Respiratory rate
Blood pressure
Pulse oximetry
Members exposed to fire smoke shall be assessed for carbon monoxide poisoning

101. Medical Monitoring
EMS shall assess and treat in accordance with protocols developed by the FD physician or medical authority.

102. Do they help?
VITAL SIGNS
MEDICAL monitoring

103. Medical Monitoring Six vital signs in rehab: Pulse rate
Respiratory rate
Blood pressure
Temperature
Oxygen saturation (SpO2)
Carboxyhemoglobin (SpCO or ExCO)

104. Medical Monitoring Pulse rate:
Pulse rate can be easily measured by palpation.
Pulse oximetry or CO-oximetry can also be used.
Oximetric pulse rates are more accurate than palpated rates.

105. Medical Monitoring Pulse rate: Normal is 60-100 beats per minute.
Common to exceed 100 during exertion. FF are often considerably higher.
After resting for a period of time, heart rate should return to normal.
Heart rate must be interpreted within the context of the individual (baseline recorded resting heart rates are helpful). FD protocols should reflect member norms.

106. The Challenge of Interpreting HR
Means currently in use:
Age based max
Percentage of baseline
“One fits all” protocol
Recent research (Illinois Fire Science Institute):
Variability xxxxx

107. Nothing new
MEDICAL MONITORING
Respiratory Rate

108. ????????
MEDICAL MONITORING
Blood Pressure

109. Medical Monitoring Blood Pressure (BP):
One of the most frequently measured and least understood vital signs.
BP measurement is extremely prone to error.
Because of the extreme variability and difficulty interpreting blood pressure changes, it remains a subject of discussion in rehab.

110. Best Practices in Rehab
THE BLOOD PRESSURE CONTROVERSY
Blood pressures measurements are prone to error and interpretations can be controversial. Members of ethnic and racial groups respond differently to physiological stress. NFPA 1584 has suggested upper limits of BP in rehab. Recent studies actually suggest hypotension (SBP < 80) may be more significant than hypertension. Additional research is needed to define the role of BP in rehab.

111. SpO2%
MEDICAL MONITORING
Pulse oximetry

112. Medical Monitoring In fire rehab, < 92% is a typical cutoff
PULSE OXIMETRY INTERPRETATION
SpO2 READING (%)
INTERPRETATION
95 – 100
Normal
91 – 94
Mild Hypoxemia
86 – 90
Moderate Hypoxemia
< 85
Severe Hypoxemia
In fire rehab, < 92% is a typical cutoff

113. NFPA 1584: 2015 Revisions Company Officer:
Awareness of FF physical/mental condition
Assure hydration
Assess his/her company every 45 min
Wildland: evaluate heat stress conditions

114. Carbon Monoxide poisoning assessment
Big Changes
MEDICAL MONITORING
Carbon Monoxide poisoning assessment

115. Medical Monitoring Carbon Monoxide (CO)
Members exposed to fire smoke shall be assessed for carbon monoxide poisoning

116. CO Assessment
Carbon monoxide is present at all fires and a leading cause of death
CO monitoring during rehab has become standard of care
Exhaled CO meter or pulse CO-Oximeter are two detection devices (or blood gases)

117. Exhaled CO Meters
Estimation COHb from alveolar CO concentration first described in (Sjostrand T. Acta Physiol Scand 16:201-7)
Predominantly used to monitor smoking cessation
Compact, portable, well validated
Requires 20 second breath holding (awake, alert patient)
Disposable mouthpieces, regular gas calibration
Despite widespread availability since 1970’s utilization very low

118. Pulse CO-Oximetry FDA approved January 2006
Compact, portable, well validated
Continuous carboxyhemoglobin measurement
Can be used on any patient (even unconscious)
No disposables, no calibration needed
Wider adoption than exhaled devices after shorter time in marketplace
Also measures oxyhemoglobin (SpO2), methemoglobin (SpMet), perfusion index (PI), hemoglobin (SpHb) and Pleth Variability Index (PVI).

119. Hemoglobin Signatures:
Extinction coefficients comparable to Absorption wavelengths of each analyte (in mm-1). Invisible spectrum range 660 to 940 nm.

120. Big Change
RELEASE
MEDICAL monitoring

121. Medical Monitoring Release from rehab:
EMS personnel shall re-evaluate members prior to release to assure no obvious indications that would prevent return to full duty.
Disposition must be:
Cleared to return
Remain in rehab
Transfer for care

122. Rehab Research Needed…

123. Thank You!