Safety of Nurse-Managed Inhaled Nitric Oxide During Critical Care Interfacility Transport

Inhaled nitric oxide (iNO) is an advanced therapy typically managed by physicians and respiratory therapists in order to increase arterial oxygenation and decrease pulmonary arterial pressure. The Johns Hopkins Lifeline Critical Care Transportation Program (Lifeline) initiated a novel nurse-managed iNO protocol in order to optimize the oxygenation of critically ill patients during interfacility transport. This study was a retrospective chart review of adverse events associated with iNO initiation or continuation by Lifeline on patients transported from March 1, 2020, to August 1, 2022. Basic demographic data and adverse events were recorded. Recorded adverse events included hypotension defined as a mean arterial pressure (MAP) < 65 mm Hg, hypoxemia defined as a decrease of ≥ 10% arterial oxygenation saturation measured by pulse oximetry, new bradycardia or tachyarrhythmia, nitrogen dioxide (NO₂) levels greater than 1.0 ppm, methemoglobinemia, and cardiac arrest. Fifteen patients were diagnosed with SARS-CoV-2 infection, of which one also had pulmonary emboli, 2 had bacterial pneumonia, 1 suffered cardiogenic shock from occlusive myocardial infarction and were on VA-ECMO, and 2 had significant thoracic trauma resulting in pulmonary contusions and hemopneumothorax. iNO was continued on 10 patients and initiated on 8 patients, 2 of whom were transitioned from inhaled epoprostenol. Hypotension occurred in 3 (16.7%) patients and one (5.56%) of the hypotensive patients subsequently went on to experience new atrial fibrillation with vasopressor titration. No patients developed worsening hypoxemia, elevated NO₂ levels, methemoglobinemia, or suffered cardiac arrest. All 3 patients who experienced hypotension were already on vasopressor support and the hypotension resolved with medication titration. This study shows that iNO administration can be safely managed by appropriately trained nurses.