To a large extent, early EMS equipment began as hospital equipment that was extrapolated to the field; it was assumed that if something worked in the hospital, then it would work in the field. It soon became apparent that hospital equipment did not always perform under the more rigorous conditions of prehospital care. Over the last 30 years, equipment has evolved specifically for EMS that is better adapted to field use in terms of size, weight, and durability. This equipment is directed at resuscitating and packaging the patient for transport to the hospital and for maintenance of stability during emergency or interfacility transport. As the science of EMS continues to mature, more equipment will be scrutinized for effectiveness.¹ The four basic questions regarding efficacy of EMS equipment are:

1. 
   

   Does it do the job?

   
   
2. 
   

   Is it safe?

   
   
3. 
   

   Can it be applied to the field environment?

   
   
4. 
   

   Can it be used effectively by prehospital personnel?

The nature of EMS equipment is changing due to the expanded scope of practice by paramedics and the blurring of care levels between basic life support (BLS) and advanced life support (ALS) personnel. Equipment once considered only for ALS care is now being carried on some BLS ambulances (e.g., defibrillators and airway adjuncts). This chapter discusses EMS vehicles; communications; the electronic patient record; personal protective equipment; and specific equipment for stabilization, resuscitation, and treatment.

The vehicles may be ground ambulances, helicopters, fixed-wing aircraft, or a variety of first-response vehicles (fire engines, police cruisers, or sport utility vehicles). The most common vehicle used is the ground ambulance, categorized into three common varieties:

• 
  

  Type I: A standard truck (e.g., pick-up) chassis with a separate modular box to carry personnel, patient, and equipment

  
  
• 
  

  Type II: An enlarged van-type vehicle

  
  
• 
  

  Type III: A van chassis with an integrated modular box on the back for medical care and equipment

In types II and III, there is physical access between the driver’s and patient care compartments, as opposed to type I, in which these spaces are separate.

Ground vehicles typically have warning devices (lights and siren) as part of their equipment. Unwarranted use of red lights and sirens is dangerous for the EMS crew, the patient onboard (if present), and the general public on the streets.² Protocols or guidelines to limit the use of these devices only to times when they are medically indicated are important.

The two-way radio is an important piece of equipment carried by prehospital providers. As the arena of wireless communication changes, EMS systems will need to adapt their communications system to best fit their needs. The spectrum of frequencies available for emergency services is limited and shared with other industries that require wireless communications. In the United States, EMS services may use specific frequencies (channels) in the very high frequency (around 170 MHz), ultra-high frequency (around 460 MHz), and public safety (around 800 MHz) bands. In an attempt to create more channels for users, the Federal Communications Commission has decreased channel spacing from 25 to 12.5 kHz, and there is a Federal Communications Commission mandate to continue spacing down to 6.25 kHz. Although newer radio equipment can be reprogrammed to allow for the change in channel spacing, older equipment may not function correctly with this spacing.

EMS systems in rural or suburban settings may have no difficulties with local communications; however, as they transport patients into urban settings and attempt to communicate with urban providers, the problems of compatible frequencies and channel congestion may develop. Urban systems may use trunking, in which communications pathways are managed by a central processor between end users, allowing large numbers of users to share a relatively small number of communications frequencies. Trunked systems may be analog, very high frequency/ultra-high frequency digital radio, or 800-MHz digital radio. An 800-MHz digital trunked system is popular because of the advantages of shared equipment between different providers (EMS, police, and fire), enhanced radio coverage, shared or lowered cost, and wide-area communications. The main disadvantage with all trunked systems is the cost necessary to upgrade the current system. In the United States, 800-MHz trunking is slowly being implemented for emergency services providers, largely due to sponsorship by the U.S. Department of Homeland Security, because of improved communications during terrorist incidents and other disasters. Although 800 MHz is a more effective means of communication, the transition to it is slow due to the difficulties with simultaneous upgrading by police, fire, and EMS.

Many urban and suburban EMS providers are choosing cellular/personal communication systems as a means of communication. These systems are abundant in urban settings because they are often inexpensive and easier to use. However, at times, these cellular/personal communication systems are congested, and there are still dead spots, even in urban areas. During many disasters, when landline phones have not worked, cellular systems have also failed to function, so reliance on cell service during major incidents is problematic.^3,4

Use of the prehospital electronic medical record has increased substantially over the past 5 years. As usage of these electronic systems increases, research and system quality assurance analysis should become easier because of better data access.⁵

Large systems with enough resources often have their own software specifically written for that system. Smaller EMS systems often use off-the-shelf alternatives. Using one of the latter products may require either modification of a vendor’s product or modification of the EMS system workflow to make the software fully functional. Many states are in the process of generating or have already generated a common data set and are collecting statewide data, which are submitted to the state EMS agency. Local and state data systems should be coordinated so they are compatible.

One common difficulty with the prehospital electronic medical record is incompatibility with the hospital electronic medical record. This means that the ambulance record cannot be expeditiously transferred to the hospital database. Long-term solutions need to be devised to ensure that all of these record systems are compatible.

Every EMS provider must be protected against exposure to blood and other body fluids from patients. Equipment such as masks, goggles, and gloves for routine use should be carried on every EMS vehicle. On occasion, gowns or sturdy gloves may be needed.⁶

Exposure to hazardous material or biologic or chemical weapons of mass destruction requires more protective equipment. Minimum personal protective equipment for such exposure should include a high-efficiency particulate air filter mask that filters 99.97% of airborne particles 0.3 μm in diameter (or an acceptable alternative for the purpose, such as an M95 military gas mask), goggles, gloves, and protective clothing. Protective clothing should be nonabsorbent and puncture resistant (Figure 2-1).⁷

Some urban EMS providers wear soft body armor as a standard part of the uniform. Suburban and rural providers can be placed in situations that necessitate similar protection. With advances in soft-armor technology, there are now a variety of styles and levels of protection from which to choose. Although each service must consider such variables as comfort, heat, weight, and cost, for EMS providers, a combination of ballistic/stab protection is optimal.

This section reviews defibrillators, electrocardiograms, airway and ventilation adjuncts, vascular access devices, spinal immobilization, and extremity immobilization.

DEFIBRILLATORS

Defibrillators have been an essential part of prehospital care since Pantridge showed that defibrillation could be done in the field on the streets of Belfast in 1965. Early defibrillation is the most important factor in surviving a cardiac arrest. Because of this, defibrillators have become smaller and less costly to expand their use. Paramedic-staffed ALS services typically carry manual monitor/defibrillators, often with additional functions (e.g., 12-lead electrocardiogram, external cardiac pacing, and synchronized cardioversion). An increasing percentage of BLS services carry automated external defibrillators. These devices are shock advisory defibrillators. Automated external defibrillators analyze the patient’s rhythm by computer algorithm, determine if the rhythm meets defibrillation criteria, inform the operator that a shock is advised, charge the capacitor, and deliver a defibrillation when the operator pushes the appropriate button. Automated external defibrillators are designed only to shock ventricular fibrillation and very fast ventricular or supraventricular tachycardias (usually >180 beats/min). Automated external defibrillators have become so easy to use and are so effective that many health and medical organizations are promoting these devices for first-responder public safety personnel and for public-access defibrillation by laypersons.^8,9,10

Automated external defibrillators are simple and relatively inexpensive. They often do not have monitor screens that display the patient’s rhythm. This actually may be better because a rhythm on the screen may only serve to distract a non-ALS operator. The device should have recording capabilities so that the cardiac arrest can later be reviewed for medical oversight and quality assurance reasons. The medical director should be involved in choosing such devices, training in their use, establishing protocols for their use, and reviewing their use afterward for quality assurance.

A defibrillator used by ALS personnel is typically a different, more sophisticated device, usually with additional functions. Defibrillation is facilitated using hands-off combination monitoring/defibrillation adhesive pads rather than with handheld paddles. Pads give better contact with the skin and decrease skin resistance to allow for a higher success rate of rhythm conversion. It is also safer for the operator who does not have direct contact with the patient when the shock is delivered. The ALS defibrillator has a screen for interpreting rhythms and so is also used for ongoing monitoring of patients’ rhythms. It may be used for cardioversion of nonlethal rhythms or pacing bradyasystolic rhythms. Additional critical care patient monitoring can be incorporated into an ALS defibrillator, including noninvasive blood pressure, pulse oximetry, end-tidal partial pressure of carbon dioxide in intubated patients, and other physiologic parameters. ALS personnel can use these machines for closely monitoring very ill patients during emergent calls or interfacility transfers.

Modern defibrillators use biphasic waveforms for shock delivery (as opposed to the traditional monophasic waveform). Monophasic waveforms deliver energy in one direction, from the positive to the negative pole. Biphasic waveforms deliver energy in two phases, one toward the positive pole and one toward the negative pole. Biphasic defibrillators defibrillate and cardiovert at lower energy levels and thus decrease myocardial injury.¹¹

Prehospital 12-lead electrocardiograms have become increasingly important in the management of ST-elevation myocardial infarctions (STEMI). Both BLS and ALS ambulance services can perform electrocardiograms in the prehospital setting.¹² Analysis of electrocardiograms provided immediately by the electrocardiograph has demonstrated limited sensitivity for detecting ST-elevation myocardial infarction.¹³ However, sensitivity can be increased using serial prehospital electrocardiograms, training paramedics to interpret electrocardiograms, and providing computer-assisted interpretation or remote physician overread of the electrocardiogram.^14,15 Irrespective of the method of interpretation, patients with a prehospital 12-lead electrocardiogram showing ST-elevation myocardial infarction arriving at a hospital with a dedicated percutaneous coronary intervention team in place have reduced door-to-balloon time and reduced mortality when compared with similar patients arriving without a prehospital 12-lead electrocardiogram.^16,17,18

AIRWAY AND VENTILATION ADJUNCTS

In a patient with acute respiratory failure or arrest, these devices maintain a patent airway that otherwise would have to be maintained by the paramedic. In addition, some airway adjuncts aid in preventing complications of airway management, such as gastric distention or aspiration (Figure 2-2). See chapter 28, Noninvasive Airway Management, and 29, Intubation and Mechanical Ventilation, for detailed discussions of these topics.

Oral and Nasal Airways

The simplest devices for airway management after manual airway maneuvers are the oropharyngeal and nasopharyngeal airways. These basic airway adjuncts usually are paired in the field with a simple bag-valve mask device for ventilation and will work quite well together. Ventilation with the bag-valve mask can be difficult for a single person to both attain a good seal with the mask and compress the bag to produce an adequate tidal volume for the patient. It is probably more effective (especially for first-responder and ambulance personnel who do not perform the skill often) to make this a two-person task (one person to maintain the seal and one person to compress the bag to maintain tidal volume). Along with these adjuncts, effective portable suction devices are available to be carried to the patient’s side to help clear the airway.

Supraglottic Airways

More advanced airway devices are used if the patient appears to need more prolonged airway management or is at greater risk for aspiration. At the BLS level, these airways include, most commonly, the pharyngeal tracheal lumen airway (PtL^®), the esophagotracheal Combitube or King LTS-D airway, and the laryngeal mask airway (LMA^®). Each of these is used in conjunction with a bag-valve mask for ventilation. These devices are great improvements over the esophageal obturator airway and esophageal gastric tube airway, which have unacceptably high complication rates and are no longer recommended for use. Both the PtL^® and the Combitube^® are for unconscious patients >14 years and >48 inches tall. They improve the airway seal to promote better ventilation than the bag-valve mask with the oral airway and seal the esophagus off with a balloon to prevent aspiration. If either device goes into the trachea, which occurs a small percentage of the time, the device can function equivalently to an endotracheal tube. The Combitube^® may be a more reliable device than the PtL^® because the large mouth balloon of the PtL^® is more easily broken than the more robust Combitube^® balloon, and basic emergency medical technicians (EMTs) may find ventilation easier with the Combitube^®.^19,20,21,22 There are few data on the use of the LMA^® for prehospital care. The LMA^® provides a seal for ventilation but may not prevent aspiration. One possible advantage of the LMA^® is that it may be less expensive than the Combitube^® or the PtL^®. The PtL^® and Combitube^® are mostly used by BLS ambulance personnel, but may be used by ALS personnel (or even by hospital personnel) as a fallback rescue device for a patient who has a difficult airway and cannot be intubated with an endotracheal tube (Table 2-1).^23,24,25,26