KEY POINTS

1. Respiratory failure can be ventilatory, hypoxic, or a combination of the two. Therapies for the two forms are different but can overlap. Hypoxemic respiratory failure is generally treated with oxygen therapy but may also improve with positive-pressure therapy. Ventilatory respiratory failure frequently requires mechanical ventilation.
2. Oxygen delivery systems vary widely in their characteristics. Variable-performance systems depend on factors such as respiratory rate and tidal volume and thus give only an approximate FIO₂ , whereas fixed-performance systems deliver a known FIO₂ .
3. The use of nitric oxide in acute respiratory distress syndrome leads to an improvement in oxygenation but no significant improvement in clinically relevant outcomes.
4. Metered-dose inhalers are generally preferred over nebulized bronchodilators for mechanically ventilated patients because they do not violate the ventilator circuit and thus produce fewer infections and fewer changes in ventilator performance.
5. Incentive spirometry, when used properly, can decrease pulmonary complication following abdominal surgery.
6. CPAP is as effective as incentive spirometry in preventing atelectasis in postoperative patients and is effort independent, making it a better choice for some patients.
7. In most patients PPV/PEEP improves oxygenation but decreases cardiac output. The effects of PPV on hemodynamic measurements are variable and depend on factors such as pulmonary compliance.
8. The two basic modes of mechanical ventilation are either volume-limited or pressure-limited. Both modes offer a host of advantages and disadvantages, but in general, volume-targeted modes guarantee a set minute ventilation and pressure-targeted modes offer better patient comfort and better maintenance of mean airway pressure.
9. Dual-control modes of mechanical ventilation are new modes that combine positive attributes of volume- and pressure-targeted strategies. These modes allow switching between volume- and pressure-targeted parameters.
10. The use of NIPPV in acute respiratory failure due to COPD has been shown to improve several measures of outcome, including need for intubation and mortality. In the setting of cardiogenic pulmonary edema the use of NIPPV remains controversial because of a possible increase in myocardial infarctions associated with NIPPV in this patient population.