Respiratory arrest

Respiratory arrest is a serious medical condition caused by apnea or respiratory dysfunction severe enough that it will not sustain the body (such as agonal breathing). Prolonged apnea refers to a patient who has stopped breathing for a long period of time. If the heart muscle contraction is intact, the condition is known as respiratory arrest. An abrupt stop of pulmonary gas exchange lasting for more than five minutes may permanently damage vital organs, especially the brain. Lack of oxygen to the brain causes loss of consciousness. Brain injury is likely if respiratory arrest goes untreated for more than three minutes, and death is almost certain if more than five minutes.

Damage may be reversible if treated early enough. Respiratory arrest is a life-threatening medical emergency that requires immediate medical attention and management. To save a patient in respiratory arrest, the goal is to restore adequate ventilation and prevent further damage. Management interventions include supplying oxygen, opening the airway, and means of artificial ventilation. In some instances, an impending respiratory arrest could be predetermined by signs the patient is showing, such as the increased work of breathing. Respiratory arrest will ensue once the patient depletes their oxygen reserves and loses the effort to breathe.

Respiratory arrest should be distinguished from respiratory failure. The former refers to the complete cessation of breathing, while respiratory failure is the inability to provide adequate ventilation for the body's requirements. Without intervention, both may lead to decreased oxygen in the blood (hypoxemia), elevated carbon dioxide level in the blood (hypercapnia), inadequate oxygen perfusion to tissue (hypoxia), and may be fatal. Respiratory arrest is also different from cardiac arrest, the failure of heart muscle contraction. If untreated, one may lead to the other.

One common sign of respiratory arrest is cyanosis, a bluish discoloration of the skin resulting from an inadequate amount of oxygen in the blood. If respiratory arrest remains without any treatment, cardiac arrest will occur within minutes of hypoxemia, hypercapnia or both. At this point, patients will be unconscious or about to become unconscious.

Signs and symptoms of respiratory compromise can differ with each patient. Complications from respiratory compromise are increasing rapidly across the clinical spectrum, partly due to expanded use of opioids combined with the lack of standardized guidelines among medical specialties. While respiratory compromise creates problems that are often serious and potentially life-threatening, they may be prevented with the proper tools and approach. Appropriate patient monitoring and therapeutic strategies are necessary for early recognition, intervention and treatment.

Diagnosis requires clinical evaluation, as detailed below.

After determining the scene is safe, approach the patient and attempt to converse with him or her. If the patient responds verbally, you have established that there is at least a partially patent airway and that the patient is breathing (therefore not currently in respiratory arrest). If the patient is unresponsive, look for chest rise, which is an indicator of active breathing. A sternal rub is sometimes used to further assess for responsiveness. Initial assessment also involves checking for a pulse, by placing two fingers against the carotid artery, radial artery, or femoral artery to ensure this is purely respiratory arrest and not cardiopulmonary arrest. Checking a pulse after encountering an unresponsive patient is no longer recommended for non-medically trained personnel. Once one has determined that the patient is in respiratory arrest, the steps below can help to further identify the cause of the arrest.

The first step to determining the cause of arrest is to clear and open the upper airway with correct head and neck positioning. The practitioner must lengthen and elevate the patient's neck until the external auditory meatus is in the same plane as the sternum. The face should be facing the ceiling. The mandible should be positioned upwards by lifting the lower jaw and pushing the mandible upward. These steps are known as head tilt, chin lift, and jaw thrust, respectively. If a neck or spinal injury is suspected, the provider should avoid performing this maneuver as further nervous system damage may occur. The cervical spine should be stabilized, if possible, by using either manual stabilization of the head and neck by a provider or applying a C-collar. The C-collar can make ventilatory support more challenging and can increase intracranial pressure, therefore is less preferable than manual stabilization. If a foreign body can be detected, the practitioner may remove it with a finger sweep of the oropharynx and suction. It is important that the practitioner does not cause the foreign body to be lodged even deeper into the patient's body. Foreign bodies that are deeper into the patient's body can be removed with Magill forceps or by suction. A Heimlich maneuver can also be used to dislodge the foreign body. The Heimlich maneuver consists of manual thrusts to the upper abdomen until the airway is clear. In conscious adults, the practitioner will stand behind the patient with arms around the patient's midsection. One fist will be in a clenched formation while the other hand grabs the fist. Together, both hands will thrust inward and upward by pulling up with both arms.