Pure SARS-CoV-2 related AVDS (Acute Vascular Distress Syndrome).

BACKGROUND: SARS-CoV-2 virus which targets the pulmonary vasculature is supposed to induce an intrapulmonary right to left shunt with an increased pulmonary blood flow. Such vascular injury is difficult to observe because it is hidden by the concomitant lung injury. We report here what may be, to the best of our knowledge, the first case of a pure Covid-19 related Acute Vascular Distress Syndrome (AVDS). CASE PRESENTATION: A 43-year-old physician, tested positive for Covid-19, was addressed to the emergency unit for severe dyspnoea and dizziness. Explorations were non informative with only a doubt regarding a sub-segmental pulmonary embolism (no ground-glass lesions or consolidations related to Covid-19 disease). Dyspnoea persisted despite anticoagulation therapy and normal pulmonary function tests. Contrast-enhanced transthoracic echocardiography was performed which revealed a moderate late right-to-left shunt. CONCLUSIONS: This case report highlights the crucial importance of the vascular component of the viral disease. The intrapulmonary shunt induced by Covid-19 which remains unrecognized because generally hidden by the concomitant lung injury, can persist for a long time. Contrast-enhanced transthoracic echocardiography is the most appropriate test to propose in case of persistent dyspnoea in Covid-19 patients.

Driving habits and risk factors for traffic accidents among sleep apnea patients--a European multi-centre cohort study.

Obstructive sleep apnea is associated with increased motor vehicle accident risk, and improved detection of patients at risk is of importance. The present study addresses potential risk factors in the European Sleep Apnea Database and includes patients with suspected obstructive sleep apnea [n = 8476, age 51.5 (12.5) years, body mass index 31.0 (6.6) kg m(-2) , 82.4% driver's licence holders]. Driving distance (km year(-1) ), driver's licence type, sleep apnea severity, sleepiness and comorbidities were assessed. Previously validated risk factors for accident history: Epworth Sleepiness Scale ≥16; habitual sleep time ≤5 h; use of hypnotics; and driving ≥15 000 km year(-1) were analysed across European regions. At least one risk factor was identified in male and female drivers, 68.75 and 51.3%, respectively. The occurrence of the risk factors was similar across Europe, with only a lower rate in the eastern region (P = 0.001). The mean number of risk factors increased across classes of sleep apnea severity. Frequent driving was prevalent [14.0 (interquartile range 8.0-20.0) × 10(3)  km year(-1) ] and 32.7% of drivers had severe obstructive sleep apnea [apnea-hypopnea index 50.3 (38.8-66.0) n h(-1) ]. Obesity, shorter sleep time and younger age were associated with increased traffic exposure (P ≤ 0.03). In conclusion, the risk factors associated with accident history were common among European patients with suspected obstructive sleep apnea, but varied between geographical regions. There was a weak covariation between occurrence of risk factors and clinically determined apnea severity but frequent driving, a strong risk factor for accidents, was over-represented. Systematic evaluation of accident-related risk factors is important to detect sleep apnea patients at risk for motor vehicle accidents.

An official American Thoracic Society Clinical Practice Guideline: sleep apnea, sleepiness, and driving risk in noncommercial drivers. An update of a 1994 Statement.

BACKGROUND: Sleepiness may account for up to 20% of crashes on monotonous roads, especially highways. Obstructive sleep apnea (OSA) is the most common medical disorder that causes excessive daytime sleepiness, increasing the risk for drowsy driving two to three times. The purpose of these guidelines is to update the 1994 American Thoracic Society Statement that described the relationships among sleepiness, sleep apnea, and driving risk. METHODS: A multidisciplinary panel was convened to develop evidence-based clinical practice guidelines for the management of sleepy driving due to OSA. Pragmatic systematic reviews were performed, and the Grading of Recommendations, Assessment, Development, and Evaluation approach was used to formulate and grade the recommendations. Critical outcomes included crash-related mortality and real crashes, whereas important outcomes included near-miss crashes and driving performance. RESULTS: A strong recommendation was made for treatment of confirmed OSA with continuous positive airway pressure to reduce driving risk, rather than no treatment, which was supported by moderate-quality evidence. Weak recommendations were made for expeditious diagnostic evaluation and initiation of treatment and against the use of stimulant medications or empiric continuous positive airway pressure to reduce driving risk. The weak recommendations were supported by very low-quality evidence. Additional suggestions included routinely determining the driving risk, inquiring about additional causes of sleepiness, educating patients about the risks of excessive sleepiness, and encouraging clinicians to become familiar with relevant laws. DISCUSSION: The recommendations presented in this guideline are based on the current evidence, and will require an update as new evidence and/or technologies becomes available.

Targeted hypoglossal neurostimulation for obstructive sleep apnoea: a 1-year pilot study.

Continuous positive airway pressure (CPAP) is an effective but cumbersome treatment for obstructive sleep apnoea (OSA). Noncompliant patients need alternative therapies. We studied a tongue neurostimulation approach: targeted hypoglossal neurostimulation (THN) therapy with the aura6000™ System. A multi-contact electrode positioned around the main trunk of the twelfth nerve connected to an implanted pulse generator stimulates segments of the nerve, activating dilator muscles. The primary objective was to improve the polysomnographically determined apnoea/hypopnoea index (AHI) at 3 months, and maintain the improvement after 12 months of treatment. 13 out of 14 operated patients were successfully implanted. At 12 months, the AHI decreased from 45±18 to 21±17, a 53% reduction (p<0.001). The 4% oxygen desaturation index fell from 29±20 to 15±16 and the arousal index from 37±13 to 25±14, both p<0.001. The Epworth sleepiness scale decreased from 11±7 to 8±4 (p=0.09). THN was neither painful nor awakened patients, who all complied with therapy. There were two transient tongue paresis. The present study represents the longest study of any hypoglossal neurostimulation reported to date. We conclude that THN is safe and effective to treat OSA in patients not compliant with CPAP.

Polysomnography in stable COPD under non-invasive ventilation to reduce patient-ventilator asynchrony and morning breathlessness.

BACKGROUND: Stable severe chronic obstructive pulmonary disease (COPD) patients with chronic hypercapnic respiratory failure treated by nocturnal bi-level positive pressure non-invasive ventilation (NIV) may experience severe morning deventilation dyspnea. We hypothesised that in these patients, progressive hyperinflation, resulting from inappropriate ventilator settings, leads to patient-ventilator asynchrony (PVA) with a high rate of unrewarded inspiratory efforts and morning discomfort. METHODS: Polysomnography (PSG), diaphragm electromyogram and transcutaneous capnography (PtcCO(2)) under NIV during two consecutive nights using baseline ventilator settings on the first night, then, during the second night, adjustment of ventilator parameters under PSG with assessment of impact of settings changes on sleep, patient-ventilator synchronisation, morning arterial blood gases and morning dyspnea. RESULTS: Eight patients (61 ± 8 years, FEV(1) 30 ± 8% predicted, residual volume 210 ± 30% predicted) were included. In all patients, pressure support was decreased during setting adjustments, as well as tidal volume, while respiratory rate increased without any deleterious effect on nocturnal PtcCO(2) or morning PaCO(2). PVA index, initially high (40 ± 30%) during the baseline night, decreased significantly after adjusting ventilator settings (p = 0.0009), as well as subjective perception of PVA leaks, and morning dyspnea while quality of sleep improved. CONCLUSION: The subgroup of COPD patients treated by home NIV, who present marked deventilation dyspnea and unrewarded efforts may benefit from adjustment of ventilator settings under PSG or polygraphy.

Ventilator modes and settings during non-invasive ventilation: effects on respiratory events and implications for their identification.

Compared with invasive ventilation, non-invasive ventilation (NIV) has two unique characteristics: the non-hermetic nature of the system and the fact that the ventilator-lung assembly cannot be considered as a single-compartment model because of the presence of variable resistance represented by the upper airway. When NIV is initiated, the ventilator settings are determined empirically based on a clinical evaluation and diurnal blood gas variations. However, NIV is predominantly applied during sleep. Consequently, to assess overnight patient-machine 'agreement' and efficacy of ventilation, more specific and sophisticated monitoring is needed. The effectiveness of NIV might therefore be more correctly assessed by sleep studies than by daytime assessment. The most available and simple monitoring can be done from flow and pressure curves from the mask or the ventilator circuit. Examination of these tracings can give useful information to evaluate if the settings chosen by the operator were the right ones for that patient. However, as NIV allows a large range of ventilatory parameters and settings, it is mandatory to have information about this to better understand patient-ventilator interaction. Ventilatory modality, mode of triggering, pressurisation slope, use or not of positive end expiratory pressure and type of exhalation as well as ventilator performances may all have physiological consequences. Leaks and upper airway resistance variations may, in turn, modify these patterns. This article discusses the equipment available for NIV, analyses the effect of different ventilator modes and settings and of exhalation and connecting circuits on ventilatory traces and gives the background necessary to understand their impact on nocturnal monitoring of NIV.

Dissociation between the clinical course and chest imaging in severe COVID-19 pneumonia: A series of five cases.

BACKGROUND: Although an RT-PCR test is the "gold standard" tool for diagnosing an infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), chest imaging can be used to support a diagnosis of coronavirus disease 2019 (COVID-19) - albeit with fairly low specificity. However, if the chest imaging findings do not faithfully reflect the patient's clinical course, one can question the rationale for relying on these imaging data in the diagnosis of COVID-19. AIMS: To compare clinical courses with changes over time in chest imaging findings among patients admitted to an ICU for severe COVID-19 pneumonia. METHODS: We retrospectively reviewed the medical charts of all adult patients admitted to our intensive care unit (ICU) between March 1, 2020, and April 15, 2020, for a severe COVID-19 lung infection and who had a positive RT-PCR test. Changes in clinical, laboratory and radiological variables were compared, and patients with discordant changes over time (e.g. a clinical improvement with stable or worse radiological findings) were analyzed further. RESULTS: Of the 46 included patients, 5 showed an improvement in their clinical status but not in their chest imaging findings. On admission to the ICU, three of the five were mechanically ventilated and the two others received high-flow oxygen therapy or a non-rebreather mask. Even though the five patients' radiological findings worsened or remained stable, the mean ± standard deviation partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2:FiO2) ratio increased significantly in all cases (from 113.2 ± 59.7 mmHg at admission to 259.8 ± 59.7 mmHg at a follow-up evaluation; p=0.043). INTERPRETATION: Our results suggest that in cases of clinical improvement with worsened or stable chest imaging variables, the PaO2:FiO2 ratio might be a good marker of the resolution of COVID-19-specific pulmonary vascular insult.

Case Reports: Bronchial Mucosal Vasculature Is Also Involved in the Acute Vascular Distress Syndrome of COVID-19.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which targets the pulmonary vasculature is supposed to induce an intrapulmonary right to left shunt with an increased pulmonary blood flow. We report here what may be, to the best of our knowledge, the first videoendoscopic descriptions of an hypervascularization of the bronchial mucosa in two patients hospitalized for coronavirus disease 2019 (COVID-19) pneumonia. Cases Presentation: Two patients, 27- and 37-year-old, were addressed to our Pneumology department for suspicion of COVID-19 pneumonia. Their symptoms (fever, dry cough, and dyspnoea), associated to pulmonary ground glass opacities on thoracic CT, were highly suggestive of a COVID-19 disease despite repeated negative pharyngeal swabs RT-PCR. In both patients, bronchoscopy examination using white light was unremarkable but NBI bronchoscopy revealed a diffuse hypervascularization of the mucosa from the trachea to the sub-segmental bronchi, associated with dilated submucosal vessels. RT-PCR performed in bronchoalveolar lavage (BAL) confirmed the presence of Sars-CoV-2. Conclusions: These two case reports highlight the crucial importance of the vascular component of the viral disease. We suggest that such bronchial hypervascularization with dilated vessels contributes, at least in part, to the intrapulmonary right to left shunt that characterizes the COVID-19 related Acute Vascular Distress Syndrome (AVDS). The presence of diffuse bronchial hypervascularization in the context of COVID-19 pandemic should prompt the search for Sars-CoV-2 in BAL samples.

CPAP Added to Oxygen Administration Avoid Intubation in Acute Respiratory Distress in COVID-19 Pneumonia. Case Report.

It was recently described that COVID-19 pneumonia patients had an atypical form of the ARDS syndrome and required gentle ventilation. We report here on benefits of CPAP treatment in a patient with COVID-19 pneumonia. A 63-year-old patient of African origin presented to the emergency room with COVID-19 pneumonia. Fever had started 5 days before her admission. On day 4, rapid clinical deterioration associated to a high respiratory rate and increased oxygen requirements was noted. The patient was working in an intensive care unit and refused to be intubated. Oxygen was administered at a rate of 15 litres per minute via a Boussignac valve, which initially restored normal oxygen saturation, but this treatment was poorly tolerated and the patient withdrew it after 2 h. A CPAP set at a pressure of 8 cm of water (Goodknight®) was then introduced with better tolerance, allowing the patient to wear it almost continuously for more than 38 h. The patient also benefited from the administration of methypredinsolone 40 mg. Concerning tolerance, a substantial advantage was noted for CPAP machine compared to the Boussignac valve with in addition, a clear decrease in respiratory rate. We would like to encourage the use of CPAP, better tolerated for extended hours with lower oxygen flows, in patients with COVID-19 pneumonia, where acute respiratory distress all too often leads to patient intubation and the genesis of deleterious lung lesions.

Sleep apnea: traffic and occupational accidents--individual risks, socioeconomic and legal implications.

Obstructive sleep apnea has been associated with a high risk for motor vehicle accidents, probably the highest of all risks due to medical conditions. Treatment of sleep apnea with nasal continuous positive airway pressure appears to reduce the risk of traffic accidents to the one of the general population. The risk for accidents may also be increased in untreated patients in the home and work environment. The increased risk seems unrelated to the symptom of daytime excessive sleepiness, and in many studies lacks a clear dose-response relationship with respect to the severity of apneas and hypopneas. The association of sleep apnea, chronic sleep deprivation and consumption of hypnotics or alcohol has not been thoroughly studied, although alcohol has been considered as a confounding variable in some studies. The cost of traffic accidents due to sleep apnea has been estimated to be so high that diagnosing and treating all drivers with sleep apnea in the USA would be cost saving and result in a decrease in society costs related to the disease. Driving licenses are delivered according to national legislations. These are all but uniform, especially concerning sleep apnea. Even within the European Union, where a minimum set of rules is mandatory for all countries, sleep apnea is not included in the minimum. Therefore, drivers are left in a very uncomfortable position, behaving according to the law in one country but being unlawful once the border with the neighbor country is crossed. Physicians are also in a very difficult position if they have to counsel their patients on the best attitude when travelling by car. The situation is even worse for commercial drivers, for whom the legislation is more severe but leaves sleep apnea uncovered in many countries. This is all the more disturbing if one considers that sleep apnea can be suspected, screened and diagnosed with relative ease, and that once diagnosed the adequate treatment allows for safe driving. The inclusion of sleep apnea in the European traffic license regulations would represent a step forward towards safe routes for patients and healthy people alike.