Article updated August 1, 2017
By Edward Dickinson, MD, FACEP, EMT-P
Firefighters die of stress- and heat heat-related illnesses far more often than they do of burns or injuries suffered in structural collapses. Although firefighting remains an inherently hazardous, physically demanding occupation, emergency scene rehabilitation that incorporates medical monitoring and interventions can reduce the risks of stress- and heat-related illnesses and deaths.
Several key principles form the core of emergency incident rehab operations:
- Keep all emergency personnel well hydrated and rested to minimize the occurrence of heat- and stress-related illnesses;
- Provide ongoing medical monitoring for early identification of rescue workers who show signs of stress- or heat-related illnesses;
- Immediately identify and treat any potentially serious medical conditions detected during initial or ongoing medical monitoring;
- Treat any traumatic injuries;
After appropriate rehabilitation and medical monitoring, triage personnel with one of the following dispositions:
- Returned to duty — adequately rehabbed and medically sound;
- Removed from duty — evidence of an illness or injury; or
- Transported to an appropriate medical facility for further evaluation and treatment of illness or injury.
Although these form the fundamental medical components of EIR, the means by which they are accomplished vary widely based on local practices, experience and logistics.
Why emergency incident medical monitoring?
For decades, half of all on-duty firefighter deaths have resulted from heart attacks and strokes. Emergency incident rehab assumes that if medical personnel closely monitor firefighters and other rescue personnel during periods of physical stress, vital-sign trends will help identify personnel at immediate risk for developing and succumbing to these stress-related illnesses.
Tachycardia and hyper- or hypotension are important findings in patients under physiologic stress because they represent significant alterations in cardiovascular physiology. Tachycardia increases myocardial oxygen consumption. Similarly, hypertension increases the work load on the heart, and hypotension reduces coronary artery perfusion.
Obtain baseline vitals
Most EIR medical protocols rely heavily on vital signs as the basis of medical decision making. For this reason, rehab medical personnel should obtain the baseline vital signs of firefighters and other rescue personnel prior to their involvement in an incident. Keep resting and post-aerobic vital signs for each department member confidential, but readily accessible to rehab medical personnel.
In addition to these vital-sign sets, take special note of all firefighters who regularly take prescribed beta blocker or calcium channel blocker medications. These drugs markedly alter the cardiovascular system’'s ability to regulate pulse and blood pressure (BP). Also identify personnel taking diuretics, such as Lasix, because they are more prone to dehydration.
Body temperature
The only true objective sign of heat-related emergencies, especially the development of heat stroke, is the measurement of core body temperature. Because a major goal of EIR is detecting and preventing heat-related emergencies, many EMS and fire department standard operating procedures call for monitoring of the patient’'s temperature with oral, electronic or tympanic thermometers.
Many rehab SOPs mandate obtaining temperatures on all patients with heart rates greater than 110 to 120 beats per minute on initial entry to the rehab sector. If the patient’'s temperature is greater than 100.6 F, the individual is not permitted to return to active duty or don turnout gear or a self-contained breathing apparatus (SCBA).
The Phoenix Fire Department Rehabilitation SOP states that any patient with a temperature higher than 101 F (38.3 C) must receive IV hydration and be transported to an emergency department.
Tympanic thermometers measure infrared heat generated by the eardrum and surrounding tissue, then display the temperature within one second. For this reason they are popular with many rehab units.
Tips for maintaining pre-emergency hydration
Here are three tips for pre-emergency hydration:
- Avoid heavy consumption of caffeinated beverages while on duty. They promote excessive urination.
- Avoid hangovers from excessive alcohol use. They often result in residual dehydration.
- Self-monitor your urine, making sure it remains clear in color and odor free — a sensitive indicator of hydration status. Increase fluid intake if your urine darkens.
Processing and triaging personnel
All crews must enter and exit rehab through a single designated entry point and be time-logged in by the sector staff. This helps maintain appropriate accountability. On entering rehab, fire personnel should remove their SCBAs, hoods, gloves and turnout gear. Once gear is removed, rehab personnel should evaluate each crew member for injuries and heat- and stress-related illnesses.
The first step in rehab evaluation
Obtain entry vital signs, including blood pressure and pulse. Rehab staff should rapidly question crew members about their medical history and current symptoms. Rehab personnel must watch for potentially life-threatening complaints, such as chest pains or shortness of breath. Remember, the goal of the entry medical evaluation is to identify illnesses or injuries, not to keep firefighters from rest and rehydration.
After completing the entry evaluation, rehab staff should assign personnel to the rest and refreshment area or the medical treatment/evaluation area. Devote most of the space within the rehab sector/group to these two large, clearly designated areas. Use large, different-colored tarps to distinguish the two areas.
The entry medical evaluation determines the area where individuals are assigned. Patients assigned to the medical treatment/ evaluation area receive intensive evaluation and monitoring, rehydration and rest. Local protocols vary, but emergency personnel with pulse rates greater than 120 at entry, who have a markedly abnormal BP or who have sustained any injuries should be assigned to the medical evaluation/treatment area (see Table 1).
| Table 1: Entry Evaluation Findings Mandating Triage to the Medical Evaluation/Treatment Area
| |
| Heart Rate | >120 |
| Blood Pressure | > 200 systolic < 90 systolic >110 diastolic |
| Injuries | Any |
Patients with abnormal vital signs require ongoing vital-sign assessment while they rest, drink and eat. At a minimum, reassess these patients 20 minutes after entering the rehab sector/group. Log each patient’'s sequential vital signs and assessments on a flow sheet.
After 20 minutes of cool down with rest and rehydration, most crew members’’ vital signs will return to normal levels. Some patients may still have elevated heart rates (greater than 100 beats per minute) or other abnormal vital signs after 20 minutes (see Table 2). These patients should remain in the rehab sector for additional rest and rehydration. Some EIR SOPs prohibit such personnel from returning to duty for the remainder of the incident or shift.
| Table 2: Reevaluation Findings Mandating Continued Time in the Rehabilitation Sector | |
| Heart Rate | > 100 |
| Blood Pressure | > 160 systolic < 100 systolic > 90 diastolic |
On occasion, personnel initially triaged for simple rest and rehydration cannot tolerate oral rehydration due to nausea or vomiting. Reassign such personnel to the medical evaluation/treatment area and closely monitor them. They will likely require IV hydration by ALS providers and transport to an emergency department.
Signs and symptoms of life-threatening emergencies
During rehabilitation and medical monitoring, rehab sector/group personnel may detect signs and symptoms of potentially life-threatening emergencies. These signs and symptoms include:
- Chest pain;
- Shortness of breath;
- Altered mental status (confusion, seizures, dizziness, etc.);
- Skin hot in temperature and either moist or dry and flushed — a potential heat stroke finding;
- Irregular pulse;
- Temperature greater than 101 F;
- Pulse greater than 150 at any time;
- Pulse greater than 140 after cool down;
- Systolic BP greater than 200 mm Hg after cool down; and
- Diastolic BP greater than 130 mm Hg at any time.
If you detect any of these conditions initiate appropriate care and immediately transport the patient to an ED for further evaluation and treatment. Use of ALS is indicated for all of these conditions. However, do not delay transport from the rehab sector to the hospital if ALS is unavailable.
The exact length of time crews should spend in the rehab sector depends on their level of exhaustion and need for rest, rehydration and — during prolonged operations — nutrition. At a minimum, crews should remain in the rehab sector/group for 15 to 20 minutes. Before returning to firefighting or rescue duties, all crew members should have a repeat pulse and BP check.
Special EIR medical considerations
Traumatic injuries
All personnel who enter the rehab sector/group with traumatic injuries should be evaluated promptly, treated, then transported to a medical facility if warranted.
When determining whether to allow personnel with a minor injury to return to active on-scene duty, consider the following criteria:
- Anyone with an injury that may worsen if they return to duty should not do so. Example: wounds that may become contaminated and increase the risk of subsequent infection.
- Anyone with an injury that may in any way impair performance should not return to duty. Example: a minor sprained ankle that might cause the firefighter difficulty when climbing a ladder.
Heat-related emergencies
Prevention and treatment of heat-related emergencies (heat cramps, heat exhaustion and heat stroke) are two of the most effective medical interventions rehab routinely makes. Although heat-related emergencies are common in many EIR situations (including police tactical and prolonged rescue), they are most pronounced in firefighting for several reasons. First, fires emit heat. In structural or wildland fires, heavy fire loads may produce extreme heat. Also, the intense physical activity associated with firefighting causes firefighters’’ bodies to generate increased heat. Finally, the protective clothing firefighters wear, although essential for safety, often impairs heat loss through evaporation and convection.
Key EIR interventions for the treatment of heat-related emergencies include rest, shade, rehydration (oral or IV) and external cooling via water misters, fans or cooling vests. During fireground operations, the removal of helmets, hoods and turnout coats is an important and often overlooked cooling intervention. Although few firefighters will take off their bunker pants in rehab, removing suspenders and folding bibs down to waist level will facilitate trunk cooling.
Spotting unidentified hazards
Rehab sector personnel must watch for a pattern of unusual complaints, illnesses or injuries. Such patterns may indicate unexpected hazards. Example: If several patients at a fire scene complain of excessive salivation, runny noses and diarrhea, the fire may involve organophosphate pesticides. Complaints of burning eyes could indicate the presence of metal gases.
If rehab personnel note such unusual patterns, they must immediately report the finding to the incident commander (IC) so appropriate actions can be taken.
Notify incident command of personnel transported
If it becomes medically necessary to transport personnel out of the rehab area to the hospital for further evaluation and treatment, notify the IC to maintain accountability. Command will also need to make decisions about reassignment of the remaining members of a company or unit left on scene.
Fluids and nutritional support
The creation of formal rehabilitation operations has resulted in an increased awareness of the need for proper replacement of fluid and nutritional loss incurred by personnel during fire suppression, tactical and rescue operations. We now know that replacement of fluids is not simply a way of making firefighters feel better, but a crucial component of maintaining overall well-being by preventing dehydration, reducing the risk of heat-related emergencies and lessening cardiovascular stress in the already dehydrated firefighter.
Basic fluid and nutritional concepts
The nutritional and fluid replacement needs of firefighters and other personnel vary widely from one incident to another. While two coolers of sport drinks may be enough for a ladder and truck company working at a single room-and-contents fire, it will not suffice for firefighters involved in wildland fire suppression for 16 hours.
The ingredients to ideal nutritional support can be viewed as a balanced triangle. The three sides of the triangle consist of the fluid/nutritional needs of the personnel, the local resources available to provide for these needs and the ability of emergency personnel to retain and digest the fluids or food provided. By balancing these three factors, the appropriate type of fluid and food replacement can be determined for the personnel at a given incident.
The ability of local resources to deliver the necessary fluid and nutritional support will depend not only on the remoteness of the scene, but on more practical considerations, such as the availability of refrigeration. In all circumstances, regardless of location, the rehab sector must provide adequate water, electrolytes and energy-producing carbohydrates to ensure emergency personnel can continue to function safely at optimal levels, despite adverse environmental and physiologic conditions.
At most scenes, rehab operations consist of fluid replacement without having to provide nutrition in the form of solid foods. Therefore, from a nutritional standpoint, a knowledge of fluids, electrolytes and the key concept of maintaining water balance remains the cornerstone of most rehab operations.Fluids and electrolytes
Water and water balance
Water comprises approximately 60 percent of your total body weight. All body cells contain some water, with some holding more than others. For instance, muscle cells have higher water content than fat cells. This means that a well-toned, muscular firefighter will have higher fluid requirements than a firefighter who weighs the same amount, but whose body has a greater percentage of fat.
The term hydration refers to the amount of water the body contains. At baseline, our bodies are adequately hydrated and maintain a proper fluid balance between water lost through normal body functions and fluids taken orally in the form of liquids and water-containing foods. The body loses water by several routes, through urine, stool, exhaled moisturized air and sweat. When the body is in a normal state of activity (or inactivity), the majority of water is lost through urination. When the body is placed in a hot environment or subjected to prolonged physical activity, such as advancing a 13/4" hose line down a fire-filled hallway, the majority of water is lost through sweat. As the body works to maintain a constant temperature, it cools itself with sweat via evaporation.
Loss of adequate hydration, dehydration, is inevitable in situations of increased fluid loss during prolonged exposure to heat or strenuous activity unless water is returned to the body orally. If dehydration progresses without adequate rehydration, a person’'s performance will be affected. If 4% of body weight is lost via sweating (not an unrealistic possibility in extended operations, such as wildland fire suppression), both mental reasoning and physical abilities may be compromised. Another problem: Over-hydration can sometimes occur when excessive fluids are ingested far in excess of the amounts lost.
When dehydration begins to develop, the body takes steps to retain as much water as possible while still producing cooling sweat. The kidneys and parts of the adrenal glands are extremely sensitive to water balance. In dehydration situations, the kidneys reduce the amount of urine production and the amount of water contained in the urine. This results in personnel becoming dehydrated and in a condition referred to as negative water balance, which presents with less frequent urination and darker, stronger smelling urination as the kidneys work to retain water.
Personnel should monitor the quantity and consistency of their urine as a key indicator of water balance. Normal urine from a wellhydrated individual should be almost clear in color and without much odor. Urine that is dark or deep yellow and possesses a strong odor indicates that a negative water balance has developed, and the rescuer needs immediate rehydration.
Thirst is not a reliable indicator of dehydration. In extended operations, personnel should monitor themselves for such signs of dehydration as headache.
Ensuring that the body maintains an even balance between water that is lost and water replaced is essential to a firefighter’'s well being and the basis of a large component of rehab operations. Failure to maintain a proper water balance and allowing dehydration to develop may have significant and even catastrophic consequences.
Electrolytes
Just as water balance is an essential component of body physiology, so too is electrolyte balance. Electrolytes, chemically charged elements, are essential to proper cell function in virtually all organ systems. Key electrolytes include sodium, potassium, calcium and magnesium.
The effects of electrolytes acting on cells and cell membranes allow a wide variety of cellular activities to occur, including the movement of skeletal muscle and the beating of the heart. Marked shifts in electrolytes can result in dysfunction of much of the body’'s normal physiology. For example, a low sodium level that results from excessive sweating can result in loss of proper skeletal muscle functioning. Clinically, this loss of proper muscle functioning results in heat cramps, commonly encountered in hot environments where excessive sodium is lost in sweat, but not adequately replaced by oral intake.
Electrolytes are lost from the body via the same mechanisms as water. As with water, the body loses the majority of electrolytes in the form of sweat and urine; sweat acts as the primary mechanism of loss during periods of strenuous activity. The characteristic salty taste of sweat is due to its high sodium content.
The kidneys and adrenal glands again play a crucial role in the body’'s effort to retain electrolytes in compensation for loss through sweating. The kidneys will avidly retain sodium when the body senses that sodium is becoming depleted. Firefighters on diuretics will lose excessive amounts of electrolytes, especially potassium and magnesium because of their medication — placing them at particular risk for electrolyte abnormalities.
Therefore, during prolonged periods of exertion, it will be necessary to replace both water and electrolytes as part of rehydration.
Carbohydrates
Water and electrolytes provide the body with essential elements that help ensure normal cell and organ function. However, neither water nor electrolytes provide the body with molecules capable of producing energy within the body. Carbohydrates produce the energy that drives the body’'s metabolism.
Carbohydrates are molecules made up of carbon (C), hydrogen (H) and oxygen (O) atoms. They exist in two main forms — simple carbohydrates and complex carbohydrates. Examples of simple carbohydrates include such sugars as glucose, sucrose, dextrose, lactose and fructose. These sugars are readily available sources of energy and can be found in a variety of natural foods, including fruit and honey. Complex carbohydrates consist of molecules made up of three or more sugars. The main source for complex carbohydrates is starches, such as bread, pasta and potatoes.
The body cannot function without adequate glucose. Lack of glucose leads to cellular dysfunction. Once complex carbohydrates are ingested, they are converted to simple sugars (usually glucose), which are then used by the brain, muscles and other organs as an essential source of energy.
During physical activity the body uses increasing amounts of carbohydrates to allow it to function at optimal performance levels. The burning of carbohydrates by cells leads to depletion of carbohydrate stores, much like sweat and urine loss lead to depletion of water and electrolytes stores.
Because the body has only a limited ability to store carbohydrates, it’'s necessary to provide carbohydrate supplementation as part of rehab fluid and food replenishment. Because it takes time for digestion to convert complex carbohydrates to usable forms of simple sugars, first-line carbohydrate replacement should be in the form of simple carbohydrates. This makes energy more immediately available to the body’'s cells. Most commercially available sport drinks contain simple carbohydrates as well as water and electrolytes. In prolonged operations, complex carbohydrates can be provided in the form of such starchy foods as pastas and stews.
Food and fluid replacement strategies
Ensuring that the body maintains an adequate amount of water and electrolytes to maintain proper functioning of the body’'s cells and organs is essential to the well being of emergency personnel operating on scene at an emergency. This goal can be reached via two basic strategies: prehydration and rehydration.
1. Prehydration
Prehydration ensures that firefighters and other emergency personnel will remain adequately hydrated at all times and, if possible, enter an emergency scene with a slightly positive water balance (see tips, p. 26).
With the exception of certain prolonged operations, it will prove difficult to predict when a major response will place a firefighter in extreme physiologic stress. If you know that a physiologically stressful event is inevitable within the next hour or two, as when a task force moves up from staging, then prehydration to a positive water balance should begin.
Some career fire departments in the Southwest regions of the United States have policies that require their firefighters to maintain prehydration status while on duty during periods of prolonged high temperatures. Such policies often require on-duty personnel to drink six to eight ounces of fluid every six hours while on duty in addition to eating routine meals.
Overly aggressive prehydration can lead to overhydration. Overhydration is especially detrimental when using plain water because key electrolytes, such as sodium and potassium, can be diluted out of the body’'s cells by taking in too much water. In a hot environment, starting out with initially low electrolytes can cause more rapid onset of electrolyte-mediated heat emergencies, such as heat cramps and heat exhaustion. This should reinforce the importance of including more than just water in hydration fluids; electrolytes and carbohydrates are also crucial.
2. Rehydration
Rehydration is the principal nutritional function of the rehab sector. Emergency personnel who enter rehab should begin rehydration as soon as EMS personnel have taken their baseline vital signs.
Ideal rehydration solutions administered in the rehab sector should contain not only water, but electrolytes and simple carbohydrates. Commercially available sport drinks contain these three major components. Two additional concerns about the exact type of rehydration beverage to use:
- The beverage must possess a taste acceptable to the recipient; and
- The beverage must be easily tolerated by the gastrointestinal system without causing nausea, vomiting or other adverse consequences.
Because taste is of individual preference, rehab supplies should contain a variety if possible.
Several factors contribute to how well rehydration solutions are tolerated by the GI system. The first factor is temperature. Rehydration fluids should never be served at the extremes of temperature. When rehydrating in hot conditions, fluids should be cool, but not ice cold. Rapid ingestion of ice-cold fluids can cause painful spasms of the esophagus. Although rare, excessively cold fluids can also cause precipitous slowing of a person’'s heart rate. In cold conditions, rehydration beverages should be served warm, rather than piping hot.
Another factor that contributes greatly to the digestion of fluids is the solution’'s osmolarity. Osmolarity can be roughly defined as the thickness of a fluid as determined by the beverage’'s electrolyte and carbohydrate content. The higher the osmolarity, the longer it will take to absorb the fluid and the harder it will be to digest. Therefore, rehydration solutions served in the rehab sector should not exceed 350 mOsm/liter. If a commercial available beverage exceeds the recommended limit of 350 mOsm/liter, dilute it with water.
The final aspect of GI tolerance: prevention of gastric distention. Gastric distention can result in such unpleasantness as abdominal pain, heartburn/reflux or vomiting. Minimize gastric distention by ensuring that rehydration solutions are less than 350 mOsm/liter, administered in reasonable amounts and not carbonated.
Once the appropriate rehydration solution is selected, administer it to all personnel in the rehab sector, with the exception of those experiencing excessive nausea or vomiting. These individuals will likely require IV hydration. Provide fluid replacement both during the height of operations — as crews rotate through rehabilitation — and also once personnel are released from active on-scene duties and back in quarters.
Rehydration parameters
As a rule of thumb, crews rotating through the rehab sector and recovering from high intensity physical activity should receive 12–32 oz. of rehydration fluids during a 20-minute rehab rotation, depending on their level of dehydration. After operations are completed, emergency personnel actively involved in onscene activities should ingest an additional eight to 32 oz. of electrolyte- and carbohydrate-containing fluid during the two hours following the operation.
Having personnel self-monitor their urine after the completion of an operation can prove helpful in guiding their post-rehab sector hydration. If personnel continue to note urine dark in color or strong in odor after returning home or to the station, then additional rehydration will be necessary to return to a proper water balance. Provision of solid foods in rehab
In prolonged operations, such as wildland fire suppression or urban search-and-rescue operations, you must provide not only adequate fluid rehydration, but more comprehensive nutritional support in the form of solid foods and meals.
The provision of solid foods to firefighters and other rescue personnel is less well understood and studied than fluid rehydration. Often, once replenishment operations move into the realm of solid foods, outside agencies such as the Red Cross or fire department canteen services provide nutritional support.
Solid foods provided to emergency personnel must meet two basic criteria: It must provide adequate and thoughtful nutrition and be served easily and safely to emergency personnel on scene.
Normally our diets consist of three major types of nutrients: carbohydrates, proteins and fats. Foods served in rehab should contain all three of these components. Because of their crucial energy-producing role in body metabolism, carbohydrates should be the most prevalent nutrient group.
Whatever food is selected for the rehab sector, it must be locally available and easily served at the emergency incident scene. Logistical considerations, such as the capability of preparing, storing and serving the food in sanitary conditions, remain essential when selecting foods for the rehab sector. A bologna and cheese sandwich with a cup of hearty stew may be ideal from a nutritional aspect, but if the sandwiches spoil due to lack of refrigeration or the stew cannot be served warm due to lack of appropriate heating appliances, then the choice is impractical. Even worse is the risk of food-borne diseases, such as e. coli or salmonella, which can render all personnel useless due to vomiting and diarrhea.
One of the best weapons against food-borne disease in rehab is a food thermometer. Add one to your rehab kit. As a general rule, cold foods must be served at less than 40° F, and hot foods must be maintained at temperatures of greater than 140 F.
Minor nutritional support
Some agencies make the distinction between minor and major nutritional support. At some medium-duration incidents, it may prove necessary to provide personnel only with snack foods in the rehab sector. In this setting, complex carbohydrates are perhaps the most important content of any solid foods supplied to on-scene personnel. Fruits, such as oranges, bananas and apples, are an excellent source of complex carbohydrates. They possess the added benefit of having a high water content to augment oral rehydration with liquids. In addition, whole, fresh fruit is easily stored and served in virtually any rehabilitation setting.
Some departments use commercially available, individually packaged snack bars for minor nutritional support. Departments should have their personnel taste test these bars prior to use in rehab and reach a consensus on an acceptable taste. It does little good to rely on such bars for necessary minor nutritional support when nobody likes them and people refuse to eat them at an incident.
Major nutritional support
In prolonged operations it may be necessary to provide responders with meals as part of rehab operations. Providing meals for a large ongoing operation can represent a huge drain on departmental resources already spread thin due to the magnitude of the emergency incident. Prearranged support services from canteen services and agencies like the Red Cross will prove helpful in the provision of major nutritional support.
Preplanning specific logistics with the organization(s) that will provide major nutritional support is an essential component of departmental SOPs for rehab operations. Such preplanning should include notification and dispatch, meal planning and orientation of the outside agency to the incident command system.
Conclusion
Provision of fluid and nutritional support to emergency personnel is a pivotal part of on-scene operations. The water tank on a piece of fire apparatus can only supply the finite amount of water it brings with it to the fire scene before running out and becoming unable to function effectively without resupply. Similarly, the body of a firefighter can only run effectively for a finite time on the fluid and nutrition it had on arrival at the incident scene before needing replenishment in the rehab sector. Departmental operating procedures should have clearly specified guidelines for the establishment of a rehab sector and the preparation, storage and serving of liquids for rehydration and food for minor and major nutritional support.
About the author:
Edward Dickinson, MD, FACEP, EMT-P, is assistant professor, department of emergency medicine, Hospital of the University of Pennsylvania, Philadelphia, and medical editor of EMS1. He is co-author of “Emergency Incident Rehabilitation,” published by Brady.
References
- Dickinson ET, Weider MA: Emergency Incident Rehabilitation. Brady-IFSTA, 2000.
- Dickinson ET: Fire Service Emergency Care. Brady-IFSTA, 1999.
- Emergency Incident Rehabilitation. FEMA — U.S. Fire Administration. FA-114, July 1992. USFA Publications, P.O. Box 70274, Washington, DC 20024. Provides a sample EIR SOP.
- The Navy Seal Nutritional Manual. United States Navy.