Related Experiment Video
Updated: Sep 21, 2026

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
[Limitations of noninvasive mask ventilation in acute hypoxemic gas exchange disorders (COPD)]
1Zentrum für Pneumologie und Thoraxchirurgie, Fachklinik München-Gauting.
Abstract:
The benefit of noninvasive mask ventilation (NIMV) compared to mechanical ventilation after intubation is proven in patients with acute exacerbation of COPD. Contrary to this point the benefit is not clear in patients with acute gas exchange failure, such as in pneumonias. We tried to evaluate the efficiency of NIMV in this indication in a clinical case series. We treated 31 patients with acute gas exchange failure (pO2 52 +/- 11 Torr, APACHE II Score 20 +/- 7) with NIMV. In 18 patients (58%) blood gases improved. But during the further course 2 patients were intubated, 3 patients died. In 13 patients mask ventilation was stopped because of ineffectivity. 11 patients were intubated, 8 patients died. 3 patients were not intubated for ethical reasons. The success rate is about 20% lower than in patients with acute ventilatory insufficiency. NIMV can be used in patients with severe gas exchange failure. Until now, however, no data are available proving that the method offers significant advantages over intubation and mechanical ventilation.
Related Concept Videos
Acute Respiratory Failure-I
Definition: It is defined by specific criteria based on blood gas measurements. Hypoxemia happens when the partial pressure of oxygen (PaO2) falls below 60 mmHg. At the same time,...
Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
Acute Respiratory Failure-III
Acute Respiratory Failure-IV
Oxygen Delivering System I: Nasal Cannula and Face Mask
Nasal Cannula
A nasal cannula is a lightweight tube split at one end into two prongs and placed in the nostrils. It is typically used to deliver low to medium levels of oxygen.
Suggested flow rate: The suggested flow rate for a nasal cannula typically ranges between 1 and 6 L/min.
Oxygen percentage setting:...
Oxygen Delivering System II: Venturi Mask and Transtracheal Oxygen
Venturi Mask
The Venturi mask, named after the Venturi effect, is designed to deliver precise oxygen concentrations. It consists of a large tube with an oxygen inlet that narrows down, causing a pressure drop that pulls air in through adjustable side ports. The mask is a lightweight,...

