1.1 To ensure ventilation and management of a status asthmaticus patient is initiated and maintained according to standard.
Definitions:
- Permissive hypercapnia or controlled hypoventilation:
A strategy for management of patients requiring mechanical ventilation whereby priority is given to the prevention or limitation of severe pulmonary hyperinflation over the maintenance of normal alveolar ventilation. This involves allowing arterial CO2 to be as high as 90mmHg, with no particular emphasis on acidosis correction.
- Effective tidal volume (VTeff):
The exhaled tidal volume minus volume lost to tubing compliance.
- Minimum alveolar concentration (MAC):
The concentration of an agent in alveolar gas necessary to prevent reflex movement in 50% of patients when a standard surgical incision is made.
- VILI:
Ventilator induced lung injury.
- Heliox:
A colorless, odourless, and tasteless inert gas. It has a lower density and Reynold’s number than Nitrogen, the normal balance gas in air. The lower Reynold’s number allows it to remain in a state of laminar flow even in very small airways, where air normally tends to switch to turbulent flow. The laminar flow pattern improves alveolar emptying, and ventilation.
- Isoflurane:
A volatile agent that is used for general anesthesia but has been shown to dilate the airway through B-adrenergic receptor stimulation. It has minimal cardiovascular side effects however it can decrease systemic vascular resistance and may cause cerebral vasodilation, with increases in ICP seen in concentrations of > 1.1%.
