Management of ABCs:
The systematic approach of assessing and addressing problems with the ABCs is the foundation of the primary assessment. Most patients don't require any interventions here, however some will and it is important to know which interventions are appropriate and when to perform them.
Airway: We need to know 3 things:
Is the airway patent?
Do we need an adjunct?
Do we need suction?
In a conscious patient who is speaking clearly, without audible adventitious sounds, we can assume the airway to be patent with reasonable certainty. In patients with airway compromise such as anaphylaxis, epiglotitis, croup, or FBAO, or significant alterations in LOC, we need to intervene. As a general rule, any patient with a GCS <8 is not able to maintain their own airway. This means that we will need to open the airway with either a head-tilt-chin-lift or jaw thrust, inspect for foreign bodies, vomit, blood, or other obstructions, suction if necessary, and place either an OPA, NPA, or SGA/ ETT depending upon local protocol and level of care.
Breathing: We need to know:
Is the patient ventilating adequately (is tidal volume sufficient)?
Is the patient breathing too fast or too slow?
Is there evidence of inadequate oxygenation? (cyanosis, pallor, altered LOA).
Upon assessment of breathing, we look at rate, rhythm, and volume/quality of respirations. These factors must be considered together, rather than alone, because we ultimately need to determine:
Is the patient's breathing sufficient to support life?
Is the problem a ventilation problem or an oxygenation problem?
We need to think about this, because rate, rhythm, and volume independently can be misleading. Take a patient with DKA for example. They will be breathing rapidly and taking deep ventilations. This is because they are blowing off excess CO2 in an attempt to compensate for metabolic acidosis. If we simply assessed a rate of say, 30RPM, we might be inclined to initiate PPV. This would be a mistake because the patient's hyperventilation is important in maintaining homeostasis. We dont want to correct it. However, we may have a different patient who has a history of COPD, dyspnea, and productive cough, who is breathing at 40RPM, shallow, with diminished air entry at the bases. In this case PPV is important because the patient has a ventilation problem and is not exchanging gas efficiently at the alveolar level. Another patient may have a head injury, altered LOC and be breathing rapid, shallow, irregular respirations. This patient's rhythm and volume indicate damage to the respiratory centre. They need to be ventilated with PPV via BVM because their own respiratory control centres are not working properly.
In summary, don't just look at a single aspect of a patient's breathing before making the decision as to how to address the problem. Consider:
Rate: is it too fast, too slow, or just right for patient age.
Rhythm: Is the rhythm regular or irregular.
Volume: are respirations, shallow, deep/gasping, or normal (enough to make chest rise and fall).
Is there evidence of accessory muscle use, positioning, nasal flaring, or other signs of increased work of breathing. Remember, breathing should be a passive process, it should not require extra work.
It is also wise to get an oxygen saturation measurement early, as this can aid in determining the need for supplemental O2. Bear in mind that toxic exposures such as Cyanide, CO, and other noxious substances can present a “Normal” SPO2 measurement. If your patient is in respiratory distress, do not withold oxygen.
Circulation: We assess peripheral, and if necessary central, pulses for rate, rhythm, and strength. We also check capillary refill. We are ultimately looking for evidence of hemodynamic instability. While we may or may not be able to address the heart rate itself in the prehospital environment (depending upon level of certification) we do need to note these findings as they aid in providing the whole picture of our patient's condition. A patient who is pale, dyspneic, and presents with a rapid, irregular, weak pulse felt at the carotid only, is one we can clearly say is in shock. The absence of a radial pulse is an early indicator of hypotension, and we can make a mental note to consider IV fluid therapy shortly (potentially initiating it during our secondary assessment).
The ABCs should be assessed on patient contact, following any interventions or changes in patient status, an throughout care in order to establish trends. Any change to these 3 areas can be life threatening and needs to be dealt with immediately. Furthermore, until you have made corrections to ABC problems, YOU CANNOT MOVE ON WITH FURTHER ASSESSMENT OR TREATMENT. If the ABCs aren't working, nothing else matters.
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