Type 1 RF requires CPAP type of NIV.
Type 2 RF requires BPAP type of NIV.
PEEP=EPAP=CPAP i.e. they all mean the same!
So you can say in Type 1 RF (Hypoxic failure), the pressure we provide is PEEP or just EPAP or CPAP.
For Type 2 RF (Hypercapnic), we provide IPAP as well as EPAP. IPAP is greater than EPAP, PS (Pressure Support is the difference between IPAP and EPAP). For instance if IPAP = 15 and EPAP is 10 then PS = 15-10 i.e. 5cm H2O.
Noninvasive ventilation decreased endotracheal intubation rates and hospital mortality in acute hypoxemia non-hypercapnic respiratory failure excluding chronic obstructive pulmonary disease exacerbation and cardiogenic pulmonary edema patients. There is no sufficient scientific evidence to recommend bi-level positive airway pressure or helmet due to the limited number of trials available. Large rigorous randomized trials are needed to answer these questions definitely.
- Pre-oxygenate your patient with high flow nasal cannula at 20 – 30 LPM
- Next consider using IM Epinephrine 0.3 – 0.5mg of 1:1000. Severe asthmatics will have a hard time getting inhaled beta agonists into the small airways, but parenteral epinephrine will get into the circulation and get to where it needs to provide support.
- Non-Invasive Positive Pressure Ventilation (NIPPV)
- 2g IV Magnesium and repeat it up to 2 more times over an hour
- Give IVF at a dose of 30cc/kg because patients with acute asthma exacerbations because patients will have insensible losses.
…and many more including intubating and ventilating the Crashing Asthmatic Patient…great read.
Volume controlled ventilation
We can put a certain volume of air into the patient with each breath in mechanical ventilation.
Pressure controlled ventilation
We can put air into the patient until the pressure reaches a certain value.
We can decide how often we give the patient a breath each minute.
For example, we can give a certain volume of gas , but the flow rate will determine whether we give that volume slowly or quickly over that breath.
In other words, the oxygen concentration we give to the patient, from 21% (room air) to 100%.
What triggers the breath?
Do we have the patient decide when they want to breathe, or do we have the ventilator decide when to initiate a breath? Or indeed a combination of the two? Is it ventilator controlled or patient controlled?