Scope of the problem

Airway management is arguably the single most important skill taught to and possessed by emergency physicians. It represents the “A” of the mnemonic ABC (Airway, Breathing, Circulation), which forms the foundation for the resuscitation of critically ill and injured patients. Airway management encompasses the assessment, establishment and protection of the airway in combination with effective oxygenation and ventilation. Timely effective airway management can mean the difference between life and death, and takes precedence over all other clinical considerations with the sole exception of immediate defibrillation of the patient in cardiac arrest due to ventricular fibrillation.

This chapter reviews airway anatomy and assessment, approaches for noninvasive airway management, and indications and techniques for definitive airway management. The approach to the challenging patient with a difficult or failed airway will also be explored, as well as specialized devices, techniques and medications employed in these challenging clinical situations.

Anatomic essentials

A clear understanding of airway anatomy is requisite for advanced airway management. Internally, the airway is made up of many structures and well-defined spaces. It originates at the nasal and oral cavities (Figure 2.1). The nasal cavity extends from the nostrils to the posterior nares or choana. The nasopharynx extends from the end of the nasal cavity to the level of the soft palate. The oral cavity is bounded by the teeth anteriorly, hard and soft palate superiorly and the tongue inferiorly.

Scope of the problem

Evaluation of the patient with acute abdominal pain is one of the most challenging aspects of emergency medicine. Abdominal pain is the presenting complaint in as many as 10% of emergency department (ED) patients. Diagnostic possibilities range from immediately life-threatening conditions (e.g., ruptured abdominal aortic aneurysm (AAA)), to self-limiting (e.g., abdominal wall strain), and from common (e.g., gastroenteritis) to unusual (e.g., black widow spider bite). Though the etiology of pain is initially undetermined in as high as 30–40% of patients, recognition of surgical or life-threatening causes is more important than establishing a firm diagnosis.

Anatomic essentials

Abdominal pain is typically derived from one or more of three distinct pain pathways: visceral, parietal (somatic) and referred.

Visceral abdominal pain

Visceral abdominal pain is usually caused by distention of hollow organs or capsular stretching of solid organs. Less commonly, it is caused by ischemia or inflammation when tissue congestion sensitizes nerve endings of visceral pain fibers and lowers the threshold for stimulus. Often the earliest manifestation of a particular disease process, visceral pain may vary from a steady ache or vague discomfort to excruciating or colicky pain. If the involved organ is affected by peristalsis, the pain is often described as intermittent, crampy, or colicky in nature.

Since the visceral pain fibers are bilateral, unmyelinated, and enter the spinal cord at multiple levels, visceral abdominal pain is usually dull, poorly localized and experienced in the midline.