When a patient ceases to breathe, they are in respiratory arrest. Advanced Cardiac Life Support recognizes respiratory arrest as the absence of any respirations, or ineffective respiration (unable to maintain oxygenation) with a pulse.
The ACLS algorithm recommends the following steps be undertaken in the management of respiratory arrest:
Because hyperventilation causes hypocapnia, or low levels of carbon dioxide, healthcare providers should not hyperventilate their patients during respiratory arrest. Hypocapnia can lead to respiratory alkalosis. Hyperventilation may mean either providing breaths too rapidly, or it may mean providing too much volume. Providing breaths too rapidly can lead to "stacking" of breaths. Excessive volume causes an increase in the intrathoracic pressure, thus decreasing venous return to the heart. Decreased venous return to the heart can lead to decreased cardiac output, and subsequent poor perfusion of the body's tissues. Gastric distention is also possible, and in extreme cases, pneumothorax is possible. Any of these complications will potentially lead to poor outcomes.
A perfusing rhythm is a rhythm which results in effective contraction of the chambers of the heart, thus allowing good blood flow to the tissues. The ACLS algorithm for cardiac arrest calls for the delivery of 1 breath every 5 to 6 seconds.
When a patient is in respiratory arrest, they will lose consciousness, and the airway may become obstructed by loss of muscular tone in the tongue or the muscles of the throat. The head-tilt/chin-lift maneuver can open the airway which is obstructed by the loosening of muscular tone in the oropharynx.
If there is any suspicion of injury to the cervical spine, the jaw thrust maneuver is an appropriate alternative. There should, in fact, always be a high index of suspicion for cervical spine injury if a patient is found "down." Maintenance of stability of the cervical spine is of paramount importance to avoid compromise of the spinal cord.
There are 5 basic techniques taught in BLS that are used to ventilate a patient.
The most common way to provide positive pressure ventilation, an Ambu bag connected to a mask makes delivery more efficient. The mask may be utilized in combination with either an oropharyngeal airway or a nasal pharyngeal airway, although the oropharyngeal airway may cause gagging and vomiting, so it is reserved for UNCONSCIOUS patients without a gag reflex. The nasopharyngeal airway may be used on the unconscious patient, as well as the conscious and semi-conscious patient. The nasopharyngeal airway is also used in patients with jaw-wiring and in patients with extensive trauma to the jaw or the oropharynx.
Other causes of airway obstruction in the unconscious or somnolent patient are saliva, vomit, or blood in the oropharynx. Suctioning should be initiated in the patient with an airway occluded with bodily fluids.
Suctioning should be limited to 10 seconds or less, or hypoxemia may occur. Monitor changes in heart rate as the vagus nerve may be stimulated and bradycardia may result.
During ACLS, an advanced airway, including a laryngeal mask airway, a Combitube, or an endotracheal tube may be utilized to improve oxygenation and ventilation. With an advanced airway, there is no interruption in chest compressions. Breaths should be given at the rate of 8 to 10 breathes per minute, or every 6 to 8 seconds. Practice with these advanced airway devices is recommended prior to attempting them in a code. They should not be tried without experience and practice.