Emergency medical services (EMS) professionals can include but are not limited to emergency medical technicians, paramedics, firefighters, other trained professionals like the military and physicians. EMS providers must often meet the inclusion criteria of being healthy, willing, and able. Professionals are often excluded if they are claustrophobic, heat sensitive, or pregnant.[5] EMS teams must designate team roles and leadership in advance to training practice. The team should have general goals establish because communication will be decreased in quality once PPE levels are donned.

Training for CBRN+ET events can instill confidence in those teams selected to perform resuscitation in contaminated theaters. Current literature suggests that training in the form of consequence management with threat mitigation and mass casualty response drills have both shown to increase success.

Traditionally EMS providers have traveled into the contamination area to retrieve victims and bring them to appropriate decontamination sites near healthcare facilities in a so-called “scoop and go” type of mission.[3] This can be effective with few casualties. In the scenario of mass casualties and or an unknown CBRN threat, new research is looking into the validity of treating victims onsite to minimize the duration of injury and increase survival. This school of thought contends that historically EMS provides care onsite, why should those benefits be lost in a CBRN+ET environment. EMS providers often function to find the history of the unknown threat (find materials safety data sheets [MSDS], isolate chemicals with mass spectrometers, Geiger counters for radiation quantifications), identify patterns of different toxidromes while diagnosing and treating simultaneously. An example of this would be for the EMS team to recognize the effects of a nerve agent attack producing a cholinergic toxidrome of pinpointed pupils, sweating, and bradycardia. The provider could quickly utilize the appropriate antidote of atropine and pralidoxime.[6] EMS providers must also take-into-account the geography of their area of operations. Different zones are established and mapped based on proximity to hazards and distances from safe, clean zones.

The area of greatest risk is titled the hot zone. This is the immediate area of the CBRN+ET threat, often the area of most casualties.  Traditionally victims were retrieved by EMS providers in PPE and brought into an adjacent warm zone. The warm zone is a safe distance from the hot zone and is an area where triage and decontamination may take place. After decontamination, patients can cross the cold line and enter the cold zone where definitive medical management can occur, or safe transport to health care facilities can occur. The cold zone will also house the incident command post where leadership manages the consequences of the specific threats.[3] As EMS resuscitation in PPE evolves, a new modern model for zone utilization is being suggested. One such suggestion is to perform warm zone treatment for massive hemorrhage control, airway/antidote management, respiratory protection and oxygenation, circulatory management, and head trauma assessment (MARCH).[3] This approach aims to improve the health of victims early, so as not to delay treatment during transport and decontamination. This model has shown international military success. This benefit is very real but adds a layer of complexity, especially if the patient is in cardiopulmonary arrest.

If the patient is incapacitated, then their vitals need to be measured. It can be challenging to asses a patient’s vitals while in OSHA PPE levels A, B, and C. The decreased visibility from the hood and decreased dexterity from glove thickness are often cited as main detractors for diagnosing and treating victims in real life or mannequins in training.[7] Specifically, level A has been found the most difficult level at which to assess and treat patients. It is easier to treat patients at levels B and C than patients in level A, but more difficult than Level D.[8] To offset this difficulty, it has been suggested to place the victim on a cardiac defibrillator which will show the electrical activity of the heart and pulse or confirm death of the patient.[9] This will tell the provider if a heartbeat is present if a pulse cannot be palpated at the carotid artery due to the decreased dexterity of protective gloves. This will also be very important for the delivery of unsynchronized shocks to a victim in a shockable rhythm cardiac arrest. Utilizing a defibrillator and following auditory orders from the machine will be more challenging with the decreased hearing by operators in PPE. Another drawback would be pulseless electrical activity where there is no pulse, and the machine does not help in this instance when a pulse cannot be palpated. It cannot be stressed enough that high-quality chest compressions should be initiated and followed between heart rhythm analysis and shocks in cardiopulmonary arrest.

Chest compressions for cardiopulmonary resuscitation (CPR) have been found to be of great importance. This is a physically demanding process for the operator delivering compressions, that becomes more demanding when utilizing PPE protection levels. The suits increase temperatures with exertion, can cause fogging and visual impairment of the face shield, and decrease sensorium leading to lowered quality and rate of chest compressions, specifically decreased depth and rate. One study has shown a decrease in CPR effectiveness of 30% while in PPE.[10] The apparent challenges are keeping track of time for the duration of compression cycles. This is due to decreased auditory sensation or visual sensation to monitor 2-minute CPR cycle length. Similarly, the decreased sensation can lead to less appropriate compression location on the sternum. Known deficiencies for CPR while in PPE include increases in time to switch providers for limiting fatigue, increased time to deliver medications, and less robust seals for bag valve mask ventilation (BVM). Studies have shown training can mitigate losses in CPR efficiency to increase endurance for greater physical demand.[11] When required for continued treatment, difficult airway management entails specific challenges.

The risk of apnea and cardiac arrest have been found to be high in events of CBRN+ET.[10] Much study has been instigated to approach airway management in these austere theaters. One study emphasizes preparation to preassemble as much airway equipment as possible due to difficulty with assembly while in PPE to save time.[12] Multiple studies with emergency providers of different skill levels managing airways in mannequins have shown that laryngeal mask airways (LMAs) have been the easiest to perform in PPE, have the highest success rates for placement, and best in versatility when having to be placed in different patient positions.[13][14][14][15] The LMA placement requires appropriate sizing, collapsing of the air cuff, lubrication of device, placement of the device, and inflation of the cuff.  It has also been studied that endotracheal intubation (ETI) though better for oxygenation and ventilation, is harder to place than LMAs with poor patient positioning.  LMAs have been found to control difficult airways until patients can be positioned successfully on a gurney at the appropriate operator waist height for ETI.[15]

Endotracheal intubation is considered the gold standard for definitive airway management. ETI has shown to handle secretions of victims in CBRN+ET events better. It requires the operator to position the patient to view the glottis. The view of the glottis can be seen by the operator when rostral to the patient’s head and viewing the glottis through the pharyngeal, tracheal axis intersection. Medications are used to sedate the patient and relax musculature to allow for the passing of the ET tube through the glottis. The tube is then secured, and the patient is treated with a BVM until a ventilator is available. Studies on mannequins have shown direct laryngoscopy (DL) to be the fastest practice for ETI.[14] Studies on cadaveric patients show increased times for ETI while operators were in OSHA PPE levels.[16] Other studies have proven that DL and video laryngoscopy to be equivalent in ETI timing, although VL requires more equipment to be brought to the incident zones.[17]  Similarly, fiberoptic intubation requires more equipment to be brought into the hot zone and has had poor outcomes for visualization through the eyepiece, especially for operators wearing glasses.[2] Positioning studies of victims in CBRN events show that performing ETI with the operator lying, seated, or kneeling is ineffective, and authors suggest taking the effort and time to place the victim onto a gurney will lead to better ETI success and resuscitation times.[15][7] Of note airway, adjuncts for ETI like bougies have been found difficult to utilize. Troubleshooting glare with covering ambient light while viewing the glottis with a blanket has offered some success. After antidotes, airway and breathing have been addressed, circulation can receive focused attention.

Patients can and will often require venous access for the delivery of fluids or medications for early resuscitation during CBRN+ET events. This has been studied multiple times and placing peripheral IVs has been found to be challenging in PPE due to decreased dexterity and sensorium. Interosseous placement (IO) has been found to take significantly less time than intravenous access (IV) while wearing PPE.[18][19] Studies with operators in PPE treating mannequins have shown IO to also supersede intermuscular (IM) drug delivery times.[19]. IO can be set up more efficiently and deliver more volumes of medication that IM.  Other studies have shown greater efficacy in antidote delivery through IO access over IV, IM, and endotracheal tube delivery.[19] Immediate resuscitation while wearing PPE is the goal for emergency providers during CBRN+ET events, but definitive management occurs at the hospital. 

Patients that achieve resuscitation are later decontaminated. This can take up to 12 minutes per person.[10] Decontamination requires the use of water with or without soap and a team to remove clothing, diluting hazardous materials, and collecting wastewater to prevent secondary contamination. Israeli Defense Forces (IDF) EMS providers have had success in placing senior physicians or anesthesiologists at the triage area after decontamination to ensure definitive airway management has or will occur correctly if needed to increase survival.[8]  At this point, hospital emergency response plans can utilize algorithms to manage mass casualties and victims of CBRN+ET events. It is of important note that many patients well enough to travel will bypass EMS and seek care, this can lead to contamination and requires thorough facility management to keep cold zones free from contamination.[17]

Those team members selected to don PPE are all at risk of contamination. Contamination can be in the form of a systems error or unforeseeable circumstance. The same complications with resuscitative techniques can also occur. For example, endotracheal intubations can lead to esophageal intubations, tracheal perforations, aspiration, or possibly main stem intubations if done incorrectly. Victim and Responder can endure heat stress or dehydration from the physical demands of egress from a dangerous environment with the taxing strain of PPE equipment as added workload required for protection.

Similar to what is referred to the "golden hour" in trauma resuscitations, EMS resuscitation while in PPE success is also time dependent. Team members will be required to diagnose and treat simultaneously while arranging an evacuation. Providers should rely on symptom pattern recognition to enhance successful treatment plans. Examples of this would be toxidrome recognition. In the case of cholinergic toxicity, this includes increased vitals, mydriasis, and dry skin. In the same way, medical triage is done by treating those salvageable and most sick; injuries and contamination must be addressed per patient with a goal of treating what cannot wait before formal decontamination and definitive treatment. The clinical gestalt must be guided with emphasis on timing to intervention, decreasing overall hazard exposure and putting a large distance between the threat and the victims.

The EMS team requires a chain of command with known protocols in place. Briefing and debriefing allow for improvement from lessons learned from previous operations. Teams should be assessed physically and mentally prior to and after operations. The team is only as strong as the weakest link in the chain. Access to current data in resuscitation through ATLS, ACLS, BCLS, and PALS is necessary. Follow on training for CBRN+ET is required and necessary. Annual training to keep skill sets sharpened must be addressed. Increased preparatory training will improve success while decreasing complications of operations.