What happens if you come upon a patient who has a strong, regular pulse, but it is not breathing? This person is in respiratory arrest, and while it is similar to cardiac arrest, it is managed slightly differently and therefore deserves to be discussed separately.
What is respiratory arrest?
Respiratory arrest is a condition that exists at any point a patient stops breathing or is ineffectively breathing. It often occurs at the same time as cardiac arrest, but not always. In the context of advanced cardiovascular life support, however, respiratory arrest is a state in which a patient stops breathing but maintains a pulse. Importantly, respiratory arrest can exist when breathing is ineffective, such as agonal gasping.
What causes respiratory arrest?
We often think of cardiac arrest leading to respiratory arrest, but the respiratory system may shut down without the heart’s involvement. If the nerves and/or muscles are not capable of supporting respiration, a patient may enter respiratory arrest. One example of this is in the disease amyotrophic lateral sclerosis (Lou Gehrig’s disease). If the area of the brain that controls respiration becomes depressed, as might occur in an opioid overdose, the brain does not drive respiration. Another example is a state in which the chest might not be able to physically support respiration. This might occur externally (e.g., with a crush injury to the chest) or internally (e.g., in acute respiratory distress syndrome or tension pneumothorax). It is important to keep these possible causes of respiratory arrest in mind during resuscitation.
Respiratory arrest management
The response to respiratory arrest follows the same process as any other emerging resuscitation, namely BLS and ACLS sequences.
The BLS survey
- Check responsiveness
- Activate EMS
- Check circulation
For the purposes of respiratory arrest, the patient will have circulation and thus there is no need to defibrillate. Indeed, there is no need for chest compressions or formal CPR for that matter. Respiratory arrest management, at least initially, centers on successful ventilation.
The ACLS survey
- Differential diagnosis
The first goal is to establish an open airway in the patient. The rescuer should use the tools available to them according to a given situation and as appropriate. For instance, if the patient is found in respiratory arrest in a non-hospital setting, the rescuer may only be able to use basic airway techniques such as head tilt/chin left or jaw thrust maneuver. Incidentally, the head tilt/chin left is used when cervical spine injury is not an issue and the jaw thrust maneuver is used when an injury to the cervical spine is suspected or feared. If an oropharyngeal or nasopharyngeal airway device is available, consider using these means to assist in airway maintenance (see A Review of Airways).
When you are administering artificial respiration, you are breathing for the patient. Avoid excessive ventilation and make sure that you see the chest rise and fall with breaths. Are you providing sufficient oxygenation? If you have access to supplemental oxygen, use it. You may use 100% oxygen initially, but it is best to titrate the level of supplemental oxygen necessary to achieve blood oxygen levels of 94% or higher (based on pulse oximetry). Likewise, if you have access to quantitative waveform capnography, you can use it to monitor end tidal carbon dioxide.
Remember that a person who is in respiratory arrest may enter cardiac arrest at any moment. Therefore, it is important to check for pulses to assess circulation. If the patient enters cardiac arrest at any moment, you should follow the cardiac arrest resuscitation algorithm immediately.