Airway, breathing, circulation: Clinical decision making

The ABC acronym, which stands for airway, breathing, and circulation, helps nurses prioritize patient care. This approach can be used to make clinical decisions when caring for several patients and to guide the care of one patient with multiple concerns. Using the ABCs as a guide, nurses can rapidly make clinical decisions based on the severity of a patient's condition, ensuring the most critical issues are addressed first.

Okay, let's start with A for airway, which involves evaluating whether the patient's airway is open, patent, and clear. This has the highest priority because without an open airway, oxygen can’t reach the lungs, which can quickly lead to oxygen deprivation, brain injury, and eventually death. Cues that indicate a compromised airway include noisy breathing, like stridor, which is a high-pitched, whistling sound; gurgling or snoring respirations; choking; or being unable to speak. Injuries that could impair the airway may present as blood or secretions in the mouth or throat, as well as facial fractures or swelling. Additionally, if a patient is unconscious or obtunded, they may not be able to effectively maintain their own airway.

If the patient’s airway is secure, the next priority is B for breathing, or the process of ventilation to support gas exchange. Even with a clear airway, other conditions like chest trauma, pulmonary disease, or lung infections can impair breathing. Cues that signal breathing impairment may include dyspnea, or shortness of breath; a rapid or slow rate of breathing; nasal flaring or use of accessory muscles like the sternocleidomastoid muscles in the neck; and color changes like pallor or cyanosis. Sometimes a patient might assume the orthopneic, or tripod, position, by leaning slightly forward with their arms propped up on an overbed table or their knees to help reduce the work of breathing.

In addition, auscultation may reveal adventitious lung sounds like wheezing or rales; or there could be an absence of lung sounds altogether. Other findings include a tracheal shift, as seen in a tension pneumothorax; or paradoxical chest movement, where a section of the chest wall moves in the opposite direction compared to the rest of the chest during breathing, as seen with flail chest. Palpation may reveal fractures, or air under the tissue of the skin, called subcutaneous emphysema.

After ensuring a patient’s breathing is effective, the focus shifts to C for circulation, or the movement of blood, oxygen, and nutrients essential for vital organs and tissues. The most emergent circulatory problem is hemorrhage, since significant blood loss can impair cardiac output and lead to organ failure and death if not controlled. Signs of hemorrhage can be overt, like active bleeding or ecchymoses, or less apparent when the bleeding is internal. Other cues of impaired circulation include a weak, thready pulse; changes in heart rate, rhythm, or heart sounds; as well as fluctuations in blood pressure, prolonged capillary refill, and decreased skin temperature. Patients may also present with lightheadedness, dizziness, or unusual fatigue.

Finally, keep in mind that the exceptions to the ABC sequence are emergent situations when cardiopulmonary resuscitation is required or when massive, uncontrolled external bleeding is present. In these cases, addressing impaired circulation through hemorrhage control and chest compressions are the highest priority, and the order changes to circulation or compressions, airway, and breathing, also called CAB, to ensure blood flow to vital organs is maintained.

Now let’s look at a scenario where a nurse uses the ABCs to inform clinical decision-making and prioritize care.

Nurse Ebony is working triage in the emergency department when three patients arrive at the same time.

First is Wei, a 30-year-old who walked in with a forearm laceration sustained after falling off a motor scooter. The wound is oozing blood and Wei is holding a saturated towel over it. His vital signs are heart rate 80 beats per minute, respirations 17 breaths per minute, blood pressure 126/77 mmHg, and oxygen saturation 95 percent on room air.

The second patient is Tolulope, a 45-year-old who arrived via ambulance after suffering an asthma attack at the local state fair. Audible wheezes can be heard, and she can speak a few words at a time. Her vital signs are heart rate 119 beats per minute, respirations 31 breaths per minute, blood pressure 141/88 mmHg, and oxygen saturation 90 percent via nonrebreather mask.