Acute application of noninvasive ventilation outside the ICU: when is it safe?

The literature supporting the use of noninvasive ventilatory support (NIV) in acute respiratory failure has markedly increased over the last 20 years.1-3 Most would now consider NIV as first line therapy in the treatment of COPD exacerbations, cardiogenic pulmonary edema, and acute hypoxemic respiratory failure in a variety of settings.1-3 The vast majority of the literature supporting the use of NIV has been obtained in the ICU, seemingly the most appropriate place to provide NIV for life support. However, paralleling the use of NIV in acute respiratory failure is an increasing body of literature supporting the use of NIV for chronic respiratory failure,4,5 the most impressive being in the use of NIV in the management of chronic neuromuscular/neurologic disease,4,5 as well as the large body of literature supporting the use of CPAP to manage sleep apnea.6 The increasing support for the use of NIV for both acute and chronic respiratory disease management has blurred the guidelines on where and how to properly provide NIV. It is hard to argue against the management of patients with sleep apnea, who have been using nocturnal CPAP for years at night, on a general medical/surgical unit, or the management of the patient with neuromuscular disease who uses NIV for 8 to 16 hours a day but can sustain spontaneous breathing for hours at a time, again on a general medical/surgical unit. However, what about the patient with hypoxemic and hypercapnic acute respiratory failure, who cannot tolerate even 2 min without NIV? Should we even consider managing this patient outside the ICU? Certainly these examples are the extremes, but what about all of the patients in between, those with an exacerbation of COPD, or with cardiogenic pulmonary edema, or the postoperative patient with moderate hypoxemic respiratory failure? Do these patients require care in the ICU, or can they be managed on general medical/surgical units? In this issue of the Journal, Cabrini and associates7 provide us some guidance. They interviewed 45 patients who were successfully managed with NIV for acute respiratory failure outside the ICU. Only half of the patients reported that they received help immediately when needed. All patients reported some level of complication, although most were minor. They also reported other issues regarding patient involvement in the choice of interface and the patient’s ability to remove the mask if required. However, there are no data describing the level of severity of the respiratory failure in any of these patients. It is impossible to know if any of them required NIV for life support, or if the decision for initiating NIV occurred when the patient was admitted to the ward, or if the patient was discharged from the ICU on NIV. In addition, these results represent only those successfully managed with NIV. The authors do not report the number of patients who were on NIV outside the ICU environment during the study period. Also, patients who failed NIV, who were transferred to the ICU, or who died while on NIV were not included in these data. But most importantly, complications from NIV while the excluded patients were on the ward are not included. Although it is true that serious complications from NIV are extremely rare, what percentage of technical failure or clinical deterioration on the wards not immediately recognized is acceptable: 1 out of 10, 1 out of 100, or 1 out of 1,000? For the one patient where problems are not immediately recognized, even 1 out of 1,000,000 is too frequent.