Introduction: the call-taking process

When a patient calls 9-1-1 and speaks with a medical communications officer, the complex process of provision of care has been initiated. This first point of medical contact, the interaction between the patient and communication officer, can influence every subsequent experience of the patient during his or her prehospital and even in-hospital care. Consequently, it is essential for the communication officer to initiate and optimize the patient for the subsequent paramedic–patient contact; the paramedic in turn optimizes the patient for contact with the local emergency department (ED) or other destination.

Although many consider that the 9-1-1 medical communications center is involved only in resource allocation such as dispatching ambulances, it also has a pivotal role in the provision of patient care [1]. The accurate identification of the chief complaint by the communications officer serves as an adjunct to the field personnel by allowing them to incrementally build on the dispatch “diagnosis” and initiate the appropriate therapy. If the communications officer incorrectly identifies the chief complaint, this may result in ineffective or inappropriate prehospital therapies, and even worse, it may introduce systematic biases that affect provision of patient care from the paramedic–patient contact onward [2,3]. (For simplicity, the term paramedic will be used in this chapter, though the principles apply to all provider types including EMS physicians.)

For example, during the initial steps in the communicator–patient interview, if the chief complaint includes scene safety (e.g. drowning or electrocution case), the dispatcher decides on the protocol that best addresses the issues [3,4]. If the chief complaint involves trauma, then the dispatcher decides on the protocol that best addresses the mechanism of injury (e.g. fall, traffic accident). When the chief complaint appears to be medical in nature, the dispatcher chooses the protocol that best fits the patient’s foremost symptom, with the priority symptoms taking precedence. Regardless of which call is assessed, the subsequent dispatch information can influence the thought processes of the responding paramedics and potentially influence how the paramedics approach the patient [5]. For example, in the case of drowning or electrocution calls, the paramedics are preparing themselves for this type of call, essentially reviewing in their minds the protocols and procedures to use when approaching the patient. For all calls, the EMS personnel consider their previous experiences to determine how to proceed with the call when they initiate their own first medical contact.

En route to the patient

Just as emergency physicians do when they pick up a medical chart, view the chief complaint, and begin their approach to the patient with some element of preconceived notions based on the recorded chief complaint, so do field personnel when they are approaching the patient after being dispatched with some form of dispatch code. This can be beneficial to the paramedic in that it may immediately confer some sense that the patient has no high-priority symptoms, thereby requiring the paramedic to delve further into the reason for the EMS call. It can also be detrimental for the paramedic, in that it may mislead him or her into assuming that no priority symptoms are present when in reality one or more may be present. It may also be detrimental for the patient because it may mislead the paramedic into minimizing and/or underestimating the patient’s symptoms, which could result in inaccurate or ineffective use of protocols. This may also pose an increased risk to the patient if the paramedic has a negative interaction with the patient, leading to mistrust, and in some cases, no transport to hospital [5].

Emergency medical services personnel must compile a massive amount of information in a relatively short period of time. They must incorporate this information with their prehospital clinical skills and baseline knowledge in their clinical decision making, which is necessary to diagnose and treat patients effectively. Similar to emergency physicians, paramedics have become very fast in their decision-making processes, using strategies of both efficiency and thoroughness. Paramedics have also developed certain rules of thumb, shortcuts, and abbreviated thinking to make fast, efficient, and accurate decisions, or what clinical decision experts term heuristics [6]. Various ethnographic and descriptive studies exploring medical errors, adverse events, and near misses in EMS have shown that paramedic decision making is a predominant factor influencing patient safety in EMS [7,8].

When paramedics are interacting with a patient, there is clinical reasoning related to both the line of medical inquiry, such as the history, physical examination, and diagnostic tests, and the clinical decision making (i.e. the cognitive process of using data to evaluate, diagnose, and treat the patient) [9]. Clinical reasoning is a tremendously complex process and is under intense ongoing investigation. There is no single model of clinical decision making that adequately relates to the very complex environment that exists in the emergency setting. Rather, there are several models or strategies that individuals use in clinical decision making or cognitive performance including:

• pattern recognition or skill based (e.g. making a diagnosis immediately on entering the room, which is frequently unconscious, automatic, and based on years of experience)
  
• rule based (e.g. Advanced Cardiac Life Support algorithms)
  
• hypothetical deductive or knowledge based (considered the highest level of deduction; a clinician generates a hypothesis and uses existing and new knowledge to find an answer) [6,10].

Some experts describe a fourth model of a naturalistic or event-driven process of decision making (i.e. treating the patient first and then making the diagnosis) [6]. Interestingly, how and where paramedics make decisions and the density of decision making of paramedics in the patient journey are postulated to differ from those of other health care providers, and are under ongoing research [11].