Philipp A Pickerodt1, Moritz B T Hofferberth2, Thilo Busch2, Martin Russ2, Mahdi Taher2, Willehad Boemke2, Steffen Weber-Carstens2, Rainer Köbrich3, Erik Swenson4,5, Maria Deja6, Roland C E Francis2. 1. Department of Anesthesiology and Operative Intensive Care Medicine (CCM/CVK), Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany. philipp.pickerodt@charite.de. 2. Department of Anesthesiology and Operative Intensive Care Medicine (CCM/CVK), Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Campus Virchow-Klinikum, Augustenburger Platz 1, 13353, Berlin, Germany. 3. EKU Elektronik GmbH, Leiningen, Germany. 4. Division of Pulmonary, Critical Care and Sleep Medicine, University of Washington, Seattle, WA, USA. 5. VA Puget Sound Health Care System, Seattle, WA, USA. 6. Department of Anesthesiology and Intensive Care Medicine, University of Schleswig-Holstein, Lübeck, Germany.
Abstract
PURPOSE: Admixture of nitric oxide (NO) to the gas inspired with mechanical ventilation can be achieved through continuous, timed, or pulsed injection of NO into the inspiratory limb. The dose and timing of NO injection govern the inspired and intrapulmonary effect site concentrations achieved with different administration modes. Here we test the effectiveness and target reliability of a new mode injecting pulsed NO boluses exclusively during early inspiration. METHODS: An in vitro lung model was operated under various ventilator settings. Admixture of NO through injection into the inspiratory limb was timed either (i) selectively during early inspiration ("pulsed delivery"), or as customary, (ii) during inspiratory time or (iii) the entire respiratory cycle. Set NO target concentrations of 5-40 parts per million (ppm) were tested for agreement with the yield NO concentrations measured at various sites in the inspiratory limb, to assess the effectiveness of these NO administration modes. RESULTS: Pulsed delivery produced inspiratory NO concentrations comparable with those of customary modes of NO administration. At low (450 ml) and ultra-low (230 ml) tidal volumes, pulsed delivery yielded better agreement of the set target (up to 40 ppm) and inspiratory NO concentrations as compared to customary modes. Pulsed delivery with NO injection close to the artificial lung yielded higher intrapulmonary NO concentrations than with NO injection close to the ventilator. The maximum inspiratory NO concentration observed in the trachea (68 ± 30 ppm) occurred with pulsed delivery at a set target of 40 ppm. CONCLUSION: Pulsed early inspiratory phase NO injection is as effective as continuous or non-selective admixture of NO to inspired gas and may confer improved target reliability, especially at low, lung protective tidal volumes.
PURPOSE: Admixture of nitric oxide (NO) to the gas inspired with mechanical ventilation can be achieved through continuous, timed, or pulsed injection of NO into the inspiratory limb. The dose and timing of NO injection govern the inspired and intrapulmonary effect site concentrations achieved with different administration modes. Here we test the effectiveness and target reliability of a new mode injecting pulsed NO boluses exclusively during early inspiration. METHODS: An in vitro lung model was operated under various ventilator settings. Admixture of NO through injection into the inspiratory limb was timed either (i) selectively during early inspiration ("pulsed delivery"), or as customary, (ii) during inspiratory time or (iii) the entire respiratory cycle. Set NO target concentrations of 5-40 parts per million (ppm) were tested for agreement with the yield NO concentrations measured at various sites in the inspiratory limb, to assess the effectiveness of these NO administration modes. RESULTS: Pulsed delivery produced inspiratory NO concentrations comparable with those of customary modes of NO administration. At low (450 ml) and ultra-low (230 ml) tidal volumes, pulsed delivery yielded better agreement of the set target (up to 40 ppm) and inspiratory NO concentrations as compared to customary modes. Pulsed delivery with NO injection close to the artificial lung yielded higher intrapulmonary NO concentrations than with NO injection close to the ventilator. The maximum inspiratory NO concentration observed in the trachea (68 ± 30 ppm) occurred with pulsed delivery at a set target of 40 ppm. CONCLUSION: Pulsed early inspiratory phase NO injection is as effective as continuous or non-selective admixture of NO to inspired gas and may confer improved target reliability, especially at low, lung protective tidal volumes.
Authors: Morgan L Sherer; Jun Lei; Patrick Creisher; Minyoung Jang; Ramya Reddy; Kristin Voegtline; Sarah Olson; Kirsten Littlefield; Han-Sol Park; Rebecca L Ursin; Abhinaya Ganesan; Theresa Boyer; Diane M Brown; Samantha N Walch; Annukka A R Antar; Yukari C Manabe; Kimberly Jones-Beatty; William Christopher Golden; Andrew J Satin; Jeanne S Sheffield; Andrew Pekosz; Sabra L Klein; Irina Burd Journal: medRxiv Date: 2020-11-16