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.

Modulation of pulmonary blood flow in patients with acute respiratory failure.

BACKGROUND: Impairment of ventilation and perfusion (V/Q) matching is a common mechanism leading to hypoxemia in patients with acute respiratory failure requiring intensive care unit (ICU) admission. While ventilation has been thoroughly investigated, little progress has been made to monitor pulmonary perfusion at the bedside and treat impaired blood distribution. The study aimed to assess real-time changes in regional pulmonary perfusion in response to a therapeutic intervention. METHODS: Single-center prospective study that enrolled adult patients with ARDS caused by SARS-Cov-2 who were sedated, paralyzed, and mechanically ventilated. The distribution of pulmonary perfusion was assessed through electrical impedance tomography (EIT) after the injection of a 10-ml bolus of hypertonic saline. The therapeutic intervention consisted in the administration of inhaled nitric oxide (iNO), as rescue therapy for refractory hypoxemia. Each patient underwent two 15-min steps at 0 and 20 ppm iNO, respectively. At each step, respiratory, gas exchange, and hemodynamic parameters were recorded, and V/Q distribution was measured, with unchanged ventilatory settings. RESULTS: Ten 65 [56-75] years old patients with moderate (40%) and severe (60%) ARDS were studied 10 [4-20] days after intubation. Gas exchange improved at 20 ppm iNO (PaO2/FiO2 from 86 ± 16 to 110 ± 30 mmHg, p = 0.001; venous admixture from 51 ± 8 to 45 ± 7%, p = 0.0045; dead space from 29 ± 8 to 25 ± 6%, p = 0.008). The respiratory system's elastic properties and ventilation distribution were unaltered by iNO. Hemodynamics did not change after gas initiation (cardiac output 7.6 ± 1.9 vs. 7.7 ± 1.9 L/min, p = 0.66). The EIT pixel perfusion maps showed a variety of patterns of changes in pulmonary blood flow, whose increase positively correlated with PaO2/FiO2 increase (R2 = 0.50, p = 0.049). CONCLUSIONS: The assessment of lung perfusion is feasible at the bedside and blood distribution can be modulated with effects that are visualized in vivo. These findings might lay the foundations for testing new therapies aimed at optimizing the regional perfusion in the lungs.

Inhaled Nitric Oxide in Acute Respiratory Distress Syndrome Subsets: Rationale and Clinical Applications.

Acute respiratory distress syndrome (ARDS) is a life-threatening condition, characterized by diffuse inflammatory lung injury. Since the coronavirus disease 2019 (COVID-19) pandemic spread worldwide, the most common cause of ARDS has been the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Both the COVID-19-associated ARDS and the ARDS related to other causes-also defined as classical ARDS-are burdened by high mortality and morbidity. For these reasons, effective therapeutic interventions are urgently needed. Among them, inhaled nitric oxide (iNO) has been studied in patients with ARDS since 1993 and it is currently under investigation. In this review, we aim at describing the biological and pharmacological rationale of iNO treatment in ARDS by elucidating similarities and differences between classical and COVID-19 ARDS. Thereafter, we present the available evidence on the use of iNO in clinical practice in both types of respiratory failure. Overall, iNO seems a promising agent as it could improve the ventilation/perfusion mismatch, gas exchange impairment, and right ventricular failure, which are reported in ARDS. In addition, iNO may act as a viricidal agent and prevent lung hyperinflammation and thrombosis of the pulmonary vasculature in the specific setting of COVID-19 ARDS. However, the current evidence on the effects of iNO on outcomes is limited and clinical studies are yet to demonstrate any survival benefit by administering iNO in ARDS.

Wearable Platform for Low-Dose Inhaled Nitric Oxide Therapy

The ongoing COVID-19 pandemic has been a daunting challenge for healthcare systems worldwide. The World Health Organization has recommended various measures to reduce or limit the spread of the virus, one of which includes the use of face masks. This increase in their demand has provided a unique opportunity to improve the technology by offering, in addition to their inherent protection, therapeutic benefits. One such benefit involves inhaled nitric oxide (iNO) therapy. iNO has proven to be a beneficial therapeutic in patients with acute, hypoxemic respiratory failure and lung injury. Specifically, its potential application stems from its ability to rapidly increase oxygen partial pressure in arterial blood. However, iNO treatments generally require pressurized gas cylinders which are coupled with high costs and lack of portability. A face mask which can deliver therapeutic NO is developed using humidity-triggered NO-releasing nanoparticles. This platform can deliver a low dose of 2.1–2.5 ppm NO for 90 min in a sustained manner. Moreover, it can be stored for extended periods of time and can be easily transported due to its light weight. This NO mask has the potential to alleviate the strain that affects financially limited healthcare systems in developing regions. © 2023 The Authors. Advanced Materials Technologies published by Wiley-VCH GmbH.

Wearable Platform for Low‐Dose Inhaled Nitric Oxide Therapy

The ongoing COVID‐19 pandemic has been a daunting challenge for healthcare systems worldwide. The World Health Organization has recommended various measures to reduce or limit the spread of the virus, one of which includes the use of face masks. This increase in their demand has provided a unique opportunity to improve the technology by offering, in addition to their inherent protection, therapeutic benefits. One such benefit involves inhaled nitric oxide (iNO) therapy. iNO has proven to be a beneficial therapeutic in patients with acute, hypoxemic respiratory failure and lung injury. Specifically, its potential application stems from its ability to rapidly increase oxygen partial pressure in arterial blood. However, iNO treatments generally require pressurized gas cylinders which are coupled with high costs and lack of portability. A face mask which can deliver therapeutic NO is developed using humidity‐triggered NO‐releasing nanoparticles. This platform can deliver a low dose of 2.1–2.5 ppm NO for 90 min in a sustained manner. Moreover, it can be stored for extended periods of time and can be easily transported due to its light weight. This NO mask has the potential to alleviate the strain that affects financially limited healthcare systems in developing regions. [ FROM AUTHOR]

Impact of Dexamethasone and Inhaled Nitric Oxide on Severe Acute Kidney Injury in Critically Ill Patients with COVID-19.

BACKGROUND: Acute kidney injury (AKI) is the second most frequent condition after acute respiratory distress syndrome (ARDS) in critically ill patients with severe COVID-19 and is strongly associated with mortality. The aim of this multicentric study was to assess the impact of the specific treatments of COVID-19 and ARDS on the risk of severe AKI in critically ill COVID-19 patients. METHODS: In this cohort study, data from consecutive patients older than 18 years admitted to 6 ICUs for COVID-19-related ARDS requiring invasive mechanical ventilation were included. The incidence and severity of AKI, defined according to the 2012 KDIGO definition, were monitored during the entire ICU stay until day 90. Patients older than 18 years admitted to the ICU for COVID-19-related ARDS requiring invasive mechanical ventilation were included. RESULTS: 164 patients were included in the final analysis; 97 (59.1%) displayed AKI, of which 39 (23.8%) had severe stage 3 AKI, and 21 (12.8%) required renal replacement therapy (RRT). In univariate analysis, severe AKI was associated with angiotensin-converting enzyme inhibitors (ACEI) exposure (p = 0.016), arterial hypertension (p = 0.029), APACHE-II score (p = 0.004) and mortality at D28 (p = 0.008), D60 (p < 0.001) and D90 (p < 0.001). In multivariate analysis, the factors associated with the onset of stage 3 AKI were: exposure to ACEI (OR: 4.238 (1.307-13.736), p = 0.016), APACHE II score (without age) (OR: 1.138 (1.044-1.241), p = 0.003) and iNO (OR: 5.694 (1.953-16.606), p = 0.001). Prone positioning (OR: 0.234 (0.057-0.967), p = 0.045) and dexamethasone (OR: 0.194 (0.053-0.713), p = 0.014) were associated with a decreased risk of severe AKI. CONCLUSIONS: Dexamethasone was associated with the prevention of the risk of severe AKI and RRT, and iNO was associated with severe AKI and RRT in critically ill patients with COVID-19. iNO should be used with caution in COVID-19-related ARDS.

Inhaled Nitric Oxide for Clinical Management of COVID-19: A Systematic Review and Meta-Analysis.

BACKGROUND: Severe COVID-19 is associated with hypoxemia and acute respiratory distress syndrome (ARDS), which may predispose multiorgan failure and death. Inhaled nitric oxide (iNO) is a clinical vasodilator used in the management of acute respiratory distress syndrome (ARDS). This study evaluated the response rate to iNO in patients with COVID-19-ARDS. METHOD: We searched Medline and Embase databases in May 2022, and data on the use of iNO in the treatment of ARDS in COVID-19 patients were synthesized from studies that satisfied predefined inclusion criteria. A systematic synthesis of data was performed followed by meta-analysis. We performed the funnel plot and leave-one-out sensitivity test on the included studies to assess publication bias and possible exaggerated effect size. We compared the effect size of the studies from the Unites States with those from other countries and performed meta-regression to assess the effect of age, year of publication, and concomitant vasodilator use on the effect size. RESULTS: A total of 17 studies (including 712 COVID-19 patients) were included in this systematic review of which 8 studies (involving 265 COVID-19 patients) were subjected to meta-analysis. The overall response rate was 66% (95% CI, 47-84%) with significantly high between-studies heterogeneity (I2 = 94%, p < 0.001). The funnel plot showed publication bias, although the sensitivity test using leave-one-out analysis showed that removing any of the study does not remove the significance of the result. The response rate was higher in the Unites States, and meta-regression showed that age, year of publication, and use of concomitant vasodilators did not influence the response rate to iNO. CONCLUSION: iNO therapy is valuable in the treatment of hypoxemia in COVID-19 patients and may improve systemic oxygenation in patients with COVID-19-ARDS. Future studies should investigate the mechanism of the activity of iNO in COVID-19 patients to provide insight into the unexplored potential of iNO in general ARDS.

Evaluation of inhaled nitric oxide (iNO) treatment for moderate-to-severe ARDS in critically ill patients with COVID-19: a multicenter cohort study.

BACKGROUND: Inhaled nitric oxide (iNO) is used as rescue therapy in patients with refractory hypoxemia due to severe COVID-19 acute respiratory distress syndrome (ARDS) despite the recommendation against the use of this treatment. To date, the effect of iNO on the clinical outcomes of critically ill COVID-19 patients with moderate-to-severe ARDS remains arguable. Therefore, this study aimed to evaluate the use of iNO in critically ill COVID-19 patients with moderate-to-severe ARDS. METHODS: This multicenter, retrospective cohort study included critically ill adult patients with confirmed COVID-19 treated from March 01, 2020, until July 31, 2021. Eligible patients with moderate-to-severe ARDS were subsequently categorized into two groups based on inhaled nitric oxide (iNO) use throughout their ICU stay. The primary endpoint was the improvement in oxygenation parameters 24 h after iNO use. Other outcomes were considered secondary. Propensity score matching (1:2) was used based on the predefined criteria. RESULTS: A total of 1598 patients were screened, and 815 were included based on the eligibility criteria. Among them, 210 patients were matched based on predefined criteria. Oxygenation parameters (PaO2, FiO2 requirement, P/F ratio, oxygenation index) were significantly improved 24 h after iNO administration within a median of six days of ICU admission. However, the risk of 30-day and in-hospital mortality were found to be similar between the two groups (HR: 1.18; 95% CI: 0.77, 1.82; p = 0.45 and HR: 1.40; 95% CI: 0.94, 2.11; p= 0.10, respectively). On the other hand, ventilator-free days (VFDs) were significantly fewer, and  ICU and hospital LOS were significantly longer in the iNO group. In addition, patients who received iNO had higher odds of acute kidney injury (AKI) (OR (95% CI): 2.35 (1.30, 4.26), p value = 0.005) and hospital/ventilator-acquired pneumonia (OR (95% CI): 3.2 (1.76, 5.83), p value = 0.001). CONCLUSION: In critically ill COVID-19 patients with moderate-to-severe ARDS, iNO rescue therapy is associated with improved oxygenation parameters but no mortality benefits. Moreover, iNO use is associated with higher odds of AKI, pneumonia, longer LOS, and fewer VFDs.

High Doses of Inhaled Nitric Oxide as an Innovative Antimicrobial Strategy for Lung Infections.

Since the designation of nitric oxide as "Molecule of the Year" in 1992, the scientific and clinical discoveries concerning this biomolecule have been greatly expanding. Currently, therapies enhancing the release of endogenous nitric oxide or the direct delivery of the exogenous compound are recognized as valuable pharmacological treatments in several disorders. In particular, the administration of inhaled nitric oxide is routinely used to treat patients with pulmonary hypertension or refractory hypoxemia. More recently, inhaled nitric oxide has been studied as a promising antimicrobial treatment strategy against a range of pathogens, including resistant bacterial and fungal infections of the respiratory system. Pre-clinical and clinical findings have demonstrated that, at doses greater than 160 ppm, nitric oxide has antimicrobial properties and can be used to kill a broad range of infectious microorganisms. This review focused on the mechanism of action and current evidence from in vitro studies, animal models and human clinical trials of inhaled high-dose nitric oxide as an innovative antimicrobial therapy for lung infections.

Real-world use of inhaled nitric oxide therapy in patients with COVID-19 and mild-to-moderate acute respiratory distress syndrome.

Background: Inhaled nitric oxide (iNO) has been studied in patients with severe acute respiratory distress syndrome (ARDS) due to COVID-19 when it may be too late to impact disease course. This article aims to describe real-world iNO use and outcomes in patients with COVID-19 with mild-to-moderate ARDS in the United States. Methods: This was a retrospective medical chart review study that included patients who were ≥18 years old, hospitalized for COVID-19, met the Berlin ARDS definition, received iNO for ≥24 hours continuously during hospitalization, and had a partial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio (P/F ratio) of >100 to ≤300 mmHg at iNO initiation. Outcomes included oxygenation parameters, physician-rated Clinical Global Impression-Improvement (CGI-I) scale scores, and adverse events. Response to iNO was defined as >20% improvement in P/F ratio. Results: Thirty-seven patients at six sites were included. A P/F ratio of ≤100 was the most common reason for exclusion (n=146; 83% of excluded patients). The mean P/F ratio (SD) increased from 136.7 (34.4) at baseline to 140.3 (53.2) at 48 hours and 151.8 (50.0) at 72 hours after iNO initiation. The response rate was 62% (n=23). During hospitalization, no patient experienced adverse events, including methemoglobinaemia, airway injury, or worsening pulmonary oedema associated with iNO. At discharge, 54.0% (n=20) of patients improved or remained stable according to the CGI-I. Conclusion: In patients hospitalized with COVID-19 and mild-to-moderate ARDS, iNO was associated with improvement in the P/F ratio with no reported toxicity. This study provides additional evidence supporting a favourable benefit-risk profile for iNO in the treatment of mild-to-moderate ARDS in patients with COVID-19 infection.

Inhaled pulmonary vasodilators are not associated with improved gas exchange in mechanically ventilated patients with COVID-19: A retrospective cohort study.

PURPOSE: Measure the effect of inhaled pulmonary vasodilators on gas exchange in mechanically ventilated patients with COVID-19. METHODS: A retrospective observational cohort study at three New York University Hospitals was performed including eighty-four mechanically ventilated SARS Cov-2 nasopharyngeal PCR positive patients, sixty nine treated with inhaled nitric oxide (iNO) and fifteen with inhaled epoprostenol (iEPO). The primary outcomes were change in PAO2:FIO2 ratio, oxygenation Index (OI), and ventilatory ratio (VR) after initiation of inhaled pulmonary vasodilators. RESULTS: There was no significant change in PAO2:FIO2ratio after initiation of iNO (mean - 4.1, 95% CI -17.3-9.0, P = 0.54) or iEPO (mean - 3.4, 95% CI -19.7-12.9, P = 0.66), in OI after initiation of iNO (mean 2.1, 95% CI-0.04-4.2, P = 0.054) or iEPO (mean - 3.4, 95% CI -19.7-12.9, P = 0.75), or in VR after initiation of iNO (mean 0.17, 95% CI -0.03-0.36, P = 0.25) or iEPO (mean 0.33, 95% CI -0.0847-0.74, P = 0.11). PAO2:FIO2, OI and VR did not significantly change over a five day period starting the day prior to drug initiation in patients who received either iNO or iEPO assessed with a fixed effects model. CONCLUSION: Inhaled pulmonary vasodilators were not associated with significant improvement in gas exchange in mechanically ventilated patients with COVID-19.

Therapeutic Effects of Inhaled Nitric Oxide Therapy in COVID-19 Patients.

The global COVID-19 pandemic has become the largest public health challenge of recent years. The incidence of COVID-19-related acute hypoxemic respiratory failure (AHRF) occurs in up to 15% of hospitalized patients. Antiviral drugs currently available to clinicians have little to no effect on mortality, length of in-hospital stay, the need for mechanical ventilation, or long-term effects. Inhaled nitric oxide (iNO) administration is a promising new non-standard approach to directly treat viral burden while enhancing oxygenation. Along with its putative antiviral affect in COVID-19 patients, iNO can reduce inflammatory cell-mediated lung injury by inhibiting neutrophil activation, lowering pulmonary vascular resistance and decreasing edema in the alveolar spaces, collectively enhancing ventilation/perfusion matching. This narrative review article presents recent literature on the iNO therapy use for COVID-19 patients. The authors suggest that early administration of the iNO therapy may be a safe and promising approach for the treatment of COVID-19 patients. The authors also discuss unconventional approaches to treatment, continuous versus intermittent high-dose iNO therapy, timing of initiation of therapy (early versus late), and novel delivery systems. Future laboratory and clinical research is required to define the role of iNO as an adjunct therapy against bacterial, viral, and fungal infections.

Effects of rescue inhaled nitric oxide on right ventricle and pulmonary circulation in severe COVID-related acute respiratory distress syndrome.

PURPOSES: To assess the effects of inhaled Nitric Oxide (iNO) on right ventricle dimension and function and systolic pulmonary arterial pressures in severe Acute Respiratory Distress (ARDS) due to Sars-Cov2 (COVID) infection. MATERIALS AND METHODS: We assessed the effects of iNO on right ventricle dimension and function and systolic pulmonary arterial pressures in 12 consecutive COVID-related ARDS patients by means of serial echocardiographic exams (baseline, 12 and 24 h since iNO start). RESULTS: Inhaled NO administration did not influence systolic pulmonary arterial pressures nor RV dimension and function. No changes were detectable in ventilatory data with iNO administration. Considering the negligible effect on oxygenation, iNO use was discontinued in all cases. CONCLUSIONS: In COVID-related severe ARDS iNO administrated as rescue therapy is not able to ameliorate oxygenation nor pulmonary hypertension, as assessed by serial echocardiograms. This finding may be explained by the diffuse loss of hypoxic pulmonary vasoconstriction with increased perfusion around alveolar consolidations which characterizes COVID-related severe ARDS.

Advances in the Pharmacological Management of Pediatric Acute Respiratory Distress Syndrome.

INTRODUCTION: Noninvasive mechanical ventilation is the main supportive measure used in patients with pediatric ARDS (PARDS), but adjunctive pharmacological therapies (corticosteroids, inhaled nitric oxide [iNO], surfactant replacement therapy and neuromuscular blocking drugs) are also used, although limited data exists to inform of this practice. AREAS COVERED: The authors review the current challenges in the pharmacological management of PARDS and highlight the few certainties currently available. EXPERT OPINION: Children with PARDS must not be treated as young adults with ARDS, essentially because children's lungs differ substantially from those of adults and PARDS occurs in children differently than ARDS in adults. Pharmacological treatments available for PARDS are relatively few and, since there is great uncertainty about their effectiveness also because of the extreme heterogeneity of this syndrome, it is necessary to conduct large clinical trials using currently available definitions and considering recent pathobiological knowledge. The aim is to identify homogeneous subgroups or phenotypes of children with PARDS that may benefit from the specific pharmaceutical approach examined. It will be then necessary to link endotypes and outcomes to appropriately target therapies in future trials, but this will be possible only after it will be possible to identify the different PARDS endotypes.

Inhaled Nitric Oxide via High-Flow Nasal Cannula in Patients with Acute Respiratory Failure Related to COVID-19.

INTRODUCTION: Limited evidence exists regarding use of inhaled nitric oxide (iNO) in spontaneously breathing patients. We evaluated the effectiveness of continuous iNO via high-flow nasal cannula (HFNC) in COVID-19 respiratory failure. METHODS: We performed a multicenter cohort study of patients with respiratory failure from COVID-19 managed with HFNC. Patients were stratified by administration of iNO via HFNC. Regression analysis was used to compare the need for mechanical ventilation and secondary endpoints including hospital mortality, length of stay, acute kidney injury, need for renal replacement therapy, and need for extracorporeal life support. RESULTS: A total of 272 patients were identified and 66 (24.3%) of these patients received iNO via HFNC for a median of 88 h (interquartile range: 44, 135). After 12 h of iNO, supplemental oxygen requirement was unchanged or increased in 52.7% of patients. Twenty-nine (43.9%) patients treated with iNO compared to 79 (38.3%) patients without iNO therapy required endotracheal intubation (P = .47). After multivariable adjustment, there was no difference in need for mechanical ventilation between groups (odds ratio: 1.53; 95% confidence interval [CI]: 0.74-3.17), however, iNO administration was associated with longer hospital length of stay (incidence rate ratio: 1.41; 95% CI: 1.31-1.51). No difference was found for mortality, acute kidney injury, need for renal replacement therapy, or need for extracorporeal life support. CONCLUSION: In patients with COVID-19 respiratory failure, iNO delivered via HFNC did not reduce oxygen requirements in the majority of patients or improve clinical outcomes. Given the observed association with increased length of stay, judicious selection of those likely to benefit from this therapy is warranted.

Efficacy and safety of inhaled nitric oxide in the treatment of severe/critical COVID-19 patients: A systematic review.

OBJECTIVE: Present systematic review aimed to analyze the effect of inhaled nitric oxide (iNO) in the treatment of severe COVID-19 and to compare it to standard of care (SOC), antiviral medications, and other medicines. MATERIALS AND METHODS: Medline (PubMed), Scopus, Embase, Ovid, Web of Science, Science Direct, Wiley Online Library, BioRxiv and MedRxiv, and Cochrane (up to April 20, 2021) were the search databases. Two reviewers (SK and CK) independently selected the electronic published literature that studied the effect of nitric oxide with SOC or control. The clinical and physiological outcomes such as prevention of progressive systemic de-oxygenation/clinical improvement, mortality, duration of mechanical ventilation, improvement in pulmonary arterial pressure, and adverse events were assessed. RESULTS: The 14 retrospective/protective studies randomly assigning 423 patients met the inclusion criteria. Cumulative study of the selected articles showed that iNO has a mild impact on ventilation time or ventilator-free days. iNO has increased the partial pressure of oxygen/fraction of inspired oxygen ratio of fraction of inspired oxygen in a few patients as compared to baseline. However, in most of the studies, it does not have better outcome when compared to the baseline improvement. CONCLUSIONS: In patients with COVID-19 with acute respiratory distress syndrome, nitric oxide is linked to a slight increase in oxygenation but has no effect on mortality.

Implication of inhaled nitric oxide for the treatment of critically ill COVID-19 patients with pulmonary hypertension.

AIMS: This study aims to analyse whether inhaled nitric oxide (iNO) was beneficial in the treatment of coronavirus disease 2019 (COVID-19) patients with pulmonary hypertension. METHODS AND RESULTS: Five critically ill COVID-19 patients with pulmonary hypertension designated Cases 1-5 were retrospectively included. Clinical data before and after iNO treatment were serially collected and compared between patients with or without iNO treatment. The five cases experienced pulmonary artery systolic pressure (PASP) elevation (≥50 mmHg) at 30, 24, 33, 23, and 24 days after illness onset (d.a.o), respectively. Cases 1-3 received iNO treatment on the 24th, 13th, and 1st day after the first elevation of PASP, with concentrations varied from 10 to 20 ppm based on the changes of PASP and blood pressure for 10, 9, and 5 days, respectively. Upon iNO treatment, PASP of Cases 1 and 2 returned to normal on the 10th day and 1st day, and maintained between 50 and 58 mmHg in Case 3. Pa02 /Fi02 increased from 88 to 124, 51 to 118, and 146 to 244, respectively. SPO2 increased from 91% to 97% for Case 1 and maintained a high level above 97% for Case 2. Cardiac function remained normal in the three patients after treatment. Moreover, Cases 1 and 3 survived from severe acute respiratory syndrome coronavirus 2 infection, while Case 2 finally died on the 36th day after the first elevation of PASP due to severe complications. Both cases who did not receive iNO treatment experienced a sudden decrease of PASP and Pa02 /Fi02 due to right heart failure and then died. CONCLUSIONS: Inhaled nitric oxide treatment was beneficial in reducing and stabilizing the PASP and might also reduce the risk of right heart failure in COVID-19 with pulmonary hypertension.