Some retrospective studies demonstrate that failure of the blood gas to improve correlates with a requirement for intubation.The ABG/VBG must immediately improve, or meet some arbitrary target (noting that such targets usually aren't evidence-based).Serial clinical evaluation should show that the patient's condition is stable or improving.The patient should be able to protect their airway from aspiration.Allow for secretion clearance, if that is an issue (e.g.Provide adequate ventilatory support so that the patient is comfortable and doesn't develop respiratory muscle fatigue.appropriate goals for a patient receiving noninvasive respiratory support: As long as the patient is comfortable, protecting their airway, and stable/improving, that's OK. The goal of noninvasive respiratory support is essentially to support the patient long enough for other therapies to work (e.g. If the patient requires intubation, then the BiPAP will help pre-oxygenate prior to intubation.If the patient responds well to BiPAP, then BiPAP may be continued.When in doubt, a reasonable approach is often to support the patient on BiPAP while simultaneously preparing for intubation.(1) Acute pulmonary edema (may turn around rapidly with BiPAP and high-dose nitroglycerine infusion).Two scenarios where patients may look absolute terrible, yet do well without intubation:.patient needs procedures/scans which mandate intubation). Cardiac arrest, severe multi-organ failure.Examples of why a patient might need immediate intubation:.

For patients with multi-organ failure, these techniques are less likely to be successful (unless the cause of respiratory failure is very rapidly reversible).Noninvasive respiratory support is best suited to patients with isolated respiratory failure.If this isn't the case, then these techniques may be less safe. The remainder of this chapter assumes that patients are receiving ICU-level monitoring, with immediate capability to intubate if needed.General situations where noninvasive support doesn't work well

Pe causing dead space ventilation