Inhaled nitric oxide might be a contributing tool for successful resuscitation of cardiac arrest related to pulmonary hypertension

The role of Transmembrane Protein 16A (TMEM16A) in pulmonary hypertension

Transmembrane protein 16A (TMEM16A), a member of the TMEM16 family, is the molecular basis of Ca2+-activated chloride channels (CaCCs) and is involved in a variety of physiological and pathological processes. Previous studies have focused more on respiratory-related diseases and tumors. However, recent studies have identified an important role for TMEM16A in cardiovascular diseases, especially in pulmonary hypertension. TMEM16A is expressed in both pulmonary artery smooth muscle cells and pulmonary artery endothelial cells and is involved in the development of pulmonary hypertension. This paper presents the structure and function of TMEM16A, the pathogenesis of pulmonary hypertension, and highlights the role and mechanism of TMEM16A in pulmonary hypertension, summarizing the controversies in this field and taking into account hypertension and portal hypertension, which have similar pathogenesis. It is hoped that the unique role of TMEM16A in pulmonary hypertension will be illustrated and provide ideas for research in this area.

Inhaled nitric oxide as temporary respiratory stabilization in patients with COVID-19 related respiratory failure (INOCOV): Study protocol for a randomized controlled trial

Background

In March 2020, WHO announced the COVID-19 a pandemic and a major global public health emergency. Mortality from COVID-19 is rapidly increasing globally, with acute respiratory failure as the predominant cause of death. Many patients experience severe hypoxia and life-threatening respiratory failure often requiring mechanical ventilation. To increase safety margins during emergency anaesthesia and rapid sequence intubation (RSI), patients are preoxygenated with a closed facemask with high-flow oxygen and positive end-expiratory pressure (PEEP). Due to the high shunt fraction of deoxygenated blood through the lungs frequently described in COVID-19 however, these measures may be insufficient to avoid harmful hypoxemia. Preoxygenation with inhaled nitric oxide (iNO) potentially reduces the shunt fraction and may thus allow for the necessary margins of safety during RSI.

Methods and design

The INOCOV protocol describes a phase II pharmacological trial of inhaled nitric oxide (iNO) as an adjunct to standard of care with medical oxygen in initial airway and ventilation management of patients with known or suspected COVID-19 in acute respiratory failure. The trial is parallel two-arm, randomized, controlled, blinded trial. The primary outcome measure is the change in oxygen saturation (SpO₂), and the null hypothesis is that there is no difference in the change in SpO₂ following initiation of iNO.

Trial registration

EudraCT number 2020-001656-18; WHO UTN: U1111-1250-1698.

Protocol version: 2.0 (June 25^th, 2021).

In-Hospital Outcomes of Patients With Pulmonary Hypertension and Cirrhosis: A 6-Year Population Cohort Study of Over One Million Patients

INTRODUCTION

There is a paucity of data on the influence of sex, race, insurance, pulmonary hypertension-related complications, and cirrhosis-related complications on mortality, hospital length of stay (LOS), and total hospital charges. The aim of this study was to identify risk factors in a national population cohort (in the USA) admitted to hospital between 2012 and 2017.

METHODS

All patients aged > 18 years with pulmonary hypertension and cirrhosis, who had been admitted to hospital between 2012 and 2017, were identified from the US Nationwide Inpatient Sample (NIS), a large publicly available all-payer inpatient care database in the USA. Multivariate regression analysis was used to estimate the odds ratios of in-hospital mortality, average length of hospital stay, and hospital charges, after adjusting for age, gender, race, primary insurance payer status, hospital type and size (number of beds), hospital region, hospital teaching status, and other demographic characteristics.

RESULTS

Our study identified 1,111,594 patients who had been discharged from hospital from 2012 to 2017. Of these patients, 355,455 were admitted with pulmonary hypertension, with 9.8% having cirrhosis as a complication (n = 34,986). The analysis revealed that patients with both pulmonary hypertension and cirrhosis compared to patients with only pulmonary hypertension experience increased mortality, hospital LOS, total hospital charges, and pulmonary hypertension-related and cirrhosis-related complications. Independent positive predictors of mortality were Asian/Pacific Islander race and "other" insurance status (worker's compensation; other US health benefits plans [CHAMPUS/TRICARE, CHAMPVA, Title V]). Independent positive predictors of increased hospital LOS were black race and "other" patients (more than one race/mixed). Independent positive predictors of increased total hospital charges were male gender, Hispanic ethnicity, Asian/Pacific Islander race, and other insurance status. Pulmonary hypertension-related complications (cor pulmonale, pulmonary embolism, hemoptysis, cardiac arrest, atrial fibrillation, ventricular tachycardia) and cirrhosis-related complications (ascites, hepatorenal syndrome, hepatic encephalopathy, variceal bleeding, portal hypertension) were independent positive predictors of mortality, hospital LOS, and total hospital charges.

CONCLUSIONS

Patients with pulmonary hypertension and cirrhosis have increased mortality and hospital utilization compared to patients with only pulmonary hypertension. We identified key drivers for these outcomes. Targeted interventions, such as novel medications, right-to-left shunts, more evaluations for lung transplantation, and reversal of pulmonary vacular remodeling, are needed for the subgroups identified in this study in order to improve outcomes.