management protocols may include several components. They are inclusion and exclusion criteria, an airway management algorithm, descriptions of mandatory procedures, benchmarks for quality assurance, and parameters for difficult or failed management. Protocols should clearly delineate inclusion and exclusion criteria based on physiological parameters, which indicate failure of ventilation or oxygenation. These may include vital sings (including respiratory rate, oxygen saturation, end‐tidal carbon dioxide), respiratory mechanics (fatigue, accessory muscle use), and mental status (Glasgow Coma Scale). An airway management algorithm needs to be specific to the equipment and skills available within the system.
One example of a structured airway management algorithm is shown in Figure 2.1 [72].
How to proceed through the airway algorithm is often a matter of judgment. Furthermore, EMS clinicians may have to alter the response to the algorithm based on patient (lack of reserve) or scene (unsafe environment) conditions. Clinician judgment can be improved through case review of errors and best practices, as well as practice with high‐fidelity simulation [73, 74]. Key among these skills is the ability to recognize a difficult airway and plan contingencies for a difficult or failed airway. Given the challenges inherent in prehospital airway management it may be prudent to anticipate all prehospital airways as difficult.
Figure 2.1 Airway management algorithm. Source: Wang HE, Kupas DF, Greenwood MJ, et al. An algorithmic approach to prehospital airway management. Prehosp Emerg Care. 2005; 9:145–55.
Quality management
For airway management, quality managment begins with initial training and skills verification, ensuring that each clinician can perform airway management skills for his or her level of training. EMS clinicians should then be educated on the application of those skills in simulation and scenario‐based education. Skills maintenance should occur at regular intervals for all personnel with special attention to clinicians who have been unsuccessful in field airway management or who have not had the opportunity to manage airways in the field.
If possible, all airway management cases should be reviewed with special emphasis placed on instances of failed airway, misplaced or dislodged invasive airway devices, number of attempts, and exposure to hypoxia, hypotension, hypo/hypercarbia, and death. Continuous physiological data are now commonly available with all portable cardiac monitors and should be reviewed for each airway case. Case review requires the reliable abstraction of pertinent data elements as described in the National Association of EMS Physicians position statement on recommended guidelines for uniform reporting of data for out‐of‐hospital intubation [75]. The Ground Air Medical qUality Transport (GAMUT) quality improvement collaborative proposes measuring definitive airway management sans hypoxia/hypotension on first attempt (DASH‐1A) as the fraction of advanced airways placed on the first attempt without SpO2 <90% or systolic blood pressure <90 mmHg [76]. When available, quality data should also include time to intubation and review of video images time locked to physiological data to address issues of technique and mitigation of patient exposure to hypoxia and hypotension.
Review of airway cases should be used to inform directed feedback to the clinician, assessment of system processes that may have contributed to error, and future continuing education so that all personnel can learn from any errors. Directed clinician feedback may include case review, skill reassessment, or additional scenario‐based training. System‐based assessment should allow the medical director to examine the protocols and procedures asking the question, “Would other EMS clinicians perform similarly in the same situation?” In rare cases, it may be necessary to send an immediate system‐wide message out to prevent such a problem from recurring. Lastly, in order to improve system‐wide performance, incorporation of challenges into simulation or scenario‐based training will allow others to learn from adverese events in a safe environment.
Research
While there have been recent significant advances in airway management science, many important unanswered questions remain. In seeking new knowledge, it is important to recognize that retrospective observational data of prehospital airway management are all vulnerable to confounding by indication. Randomized controlled trial designs are necessary to result in the most accurate observations.
While informed by many observational series, the optimal approach to prehospital trauma airway management remains unclear [9]. An objective of prehospital airway management is to enable optimized ventilation. However, there have been few rigorous studies of prehospital ventilatory techniques. Davis, et al. observed that hyperventilation is common after prehospital RSI of traumatic brain injured patients and associated with worsened outcomes [46]. A before‐after study in Arizona suggested that avoidance of hypoxia, hyperventilation, and hypotension were important in optimizing traumatic brain injury outcomes [77]. The field requires additional study of ventilation strategies and mitigation of secondary injury.
Critical decision making: an illustrative vignette
Paramedics are dispatched to a patient with respiratory distress who is noted to have swelling and pain involving the submental tissues that began within the last 24 hours. He has been suffering from a tooth infection and was recently placed on penicillin and advised to see a dentist for an extraction. The crew arrives to find the gentleman with trismus and drooling. His vital signs are BP 136/84 mmHg, pulse 110/min, RR 26/min, SpO2 97% on room air. The EMS clinicians assess the patient’s airway and elect to perform RSI. They are concerned that he will not be able to protect his airway for the 20 minute transport to the emergency department. The crew prepares medications and paralyzes the patient. They are unable to advance a 4 Macintosh blade into the patient’s mouth, and switch to a 3 Miller. Over three more attempts they note significant swelling in the airway, have difficulty identifying structures, and cannot clearly visualize the vocal cords. They place an endotracheal tube but quickly remove it when it does not return EtCO2. They are forced to abandon the attempts when the patient’s oxygen saturation falls to 60% and he becomes bradycardic. They place a SGA and are able ventilate and to recover the patient’s oxygen saturation.
The medical director reviews the case and re‐educates the crew on the following points. 1) Given the patient’s ability to protect his own airway it may have been better to manage the patient conservatively, keeping him upright with humidified oxygen and suction (know when not to intubate). 2) When it is clear that there will be a difficult airway, ask for additional resources including, perhaps, a second unit, supervisor, EMS physician, or critical care team (call for help). 3) Intubation attempts should be discontinued if they are not likely to be successful. The conditions of the intubation (positioning, equipment, or clinician) should be changed after a failed attempt. 4) The backup plan should be discussed prior to the attempt and prepared for implementation. The crew recreated this scenario in a high‐fidelity simulation to review alternative actions that could have resulted in a better outcome. The simulation included multiple iterations of the scenario and debriefing to discuss the points noted above. The scenario was then used to build a simulation demonstrating and evaluating decision making for all the paramedics in the service during the following year’s education sessions.
References
1 1 Thomas JB, Abo BN, Wang HE. Paramedic perceptions of challenges in out‐of‐hospital endotracheal intubation. Prehosp Emerg Care. 2007; 11:219–23.
2 2 Pollock MJ, Brown LH, Dunn KA. The perceived importance of paramedic skills and the emphasis they receive during EMS education programs. Prehosp Emerg Care. 1997; 1:263–8.
3 3 Stewart RD, Paris PM, Winter PM, Pelton GH, Cannon GM. Field endotracheal intubation by paramedical personnel. Success