Airway Management and Mechanical Ventilation Basics
The goal of airway management is to ensure that the patient has a patent airway through which effective ventilation can take place. An obstructed airway causes the body to be deprived of oxygen and, if ventilation isn’t reestablished, causes brain death within minutes. When a patient is critically ill and requires an artificial airway and mechanical ventilation, it is the responsibility of the healthcare professionals caring for the patient to ensure that the airway is secure, and that it’s as close to the patient’s natural airway as possible. This means mechanically performing physiological functions such as humidifying inspired air and removing secretions.
Mechanical ventilation is used when a patient is unable to breathe adequately on his or her own. The ventilator can either completely take over respiratory function, or it can be used to support the patient’s own respiratory efforts.
Indications for Mechanical Ventilation
The patient experiencing respiratory failure or arrest is the first type of patient most of us think of when we hear “mechanical ventilation.” The code scenario described above is a classic clinical situation; if the patient survives the code, we know he will be transferred to the ICU on a ventilator. Similarly, any patient experiencing respiratory distress with impaired gas exchange or increased work of breathing is likely to be intubated and mechanically ventilated, hopefully before he or she reaches the point of respiratory arrest.
Mechanical ventilation can also be used in other situations. For example, relieving the work involved with breathing decreases myocardial and systemic oxygen consumption. This is particularly beneficial for patients who have both respiratory and cardiac failure. The increased work of breathing resulting from respiratory distress or fatigue puts extra stress on the heart, which can lead to a cardiac event. A diminished work of breathing also decreases intracranial pressure, thus mechanical ventilation is often used in patients with brain injuries.
In some cases, it’s advantageous for a patient to be heavily sedated or even pharmacologically paralyzed. Patients with brain injuries may be placed in a barbiturate coma in order to decrease the metabolism and use of oxygen in the brain. This facilitates healing and reduces the risk of further ischemic brain injury. Likewise, patients who are admitted after ingesting drugs or alcohol, or who are experiencing drug or alcohol withdrawal, may be violent and a safety risk to themselves and others. They may be pharmacologically sedated and paralyzed during this time, especially if they are hospitalized for another physical problem or injury that could be exacerbated by their behavior, such as myocardial infarction, trauma, or after surgery.
Finally, mechanical ventilation may be used to provide stability of the chest wall after trauma or surgery if movement or coughing would disrupt broken bones or surgical incisions. In this case, the patient would likely be heavily sedated and pharmacologically paralyzed to inhibit any spontaneous movement.
Role of the Registered Nurse
Nurses are constantly present at the patient’s bedside, so they are the primary healthcare professionals responsible for monitoring the patient’s respiratory status. They are expected to keep an eye on any equipment required by the patient, including ventilators and monitoring equipment, and to respond to monitor alarms. The nurse is also responsible for notifying the respiratory therapist when mechanical problems occur with the ventilator, and when there are new physician orders that call for changes in the settings or the alarm parameters.
The nurse is responsible for documenting frequent respiratory assessments. This usually means documenting ventilator settings and spontaneous respiratory parameters every hour, with a full respiratory assessment, including lung sounds, at least every four hours. The nurse also performs suctioning and provides oral and site care around the artificial airway. There is often a great deal of teaching and reassuring that must be done, both for the patient (if alert) and family; the nurse is in a prime position to address those needs.
Role of the Respiratory Therapist
The respiratory therapist (RT) is generally responsible for setting up the ventilator, doing the daily check, changing ventilator settings based on physician’s orders, and performing general ventilator maintenance.
The RT is also responsible for assessing the patient’s respiratory status and performing suctioning. RTs usually round on their assigned patients every two hours to document the ventilator settings and the patient’s spontaneous respiratory parameters. The RT and nurse must communicate so each knows when the patient was last suctioned. The RT is also responsible for performing weaning criteria on patients who may be extubated and communicating the results to the nurse.