Mechanical ventilation is a therapeutic intervention used to support ventilation, move air in and out of the lungs, and optimize oxygenation by facilitating the transport of gases from the atmosphere to the alveoli to promote gas exchange. Although ventilators can improve alveolar ventilation, they do not have the capacity to perform external respiration, which is the diffusion of gases across the alveolar-capillary membrane. Mechanical ventilators are used to support the patient’s respiratory status until the underlying reason for ventilation can be corrected.
There are two main types of acute respiratory failure. Type I failure (hypoxemic or oxygenation failure) occurs when the body cannot deliver an adequate supply of oxygen to the arterial blood. Type II failure (hypercapnic or ventilatory failure) occurs when the body cannot adequately eliminate carbon dioxide from arterial blood. Patients therefore can develop oxygenation failure or ventilation failure that can both result in respiratory failure requiring mechanical ventilation. It can be difficult to determine which type of failure the patient may be exhibiting and requires frequent monitoring and interpretation of PaO2 and PaCO2 values.
Upon completion of this section, you will be able to:
The following series of videos has been produced to help non-ICU clinicians prepare for caring for patients requiring mechanical ventilation during COVID crisis. Please review the following: