Refractory Hypoxemia Research Articles

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

BackgroundInhaled 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.MethodsThis 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.ResultsA 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).ConclusionIn 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.

RARE CASE OF SEVERE NECROTIZING PNEUMONIA DUE TO STREPTOCOCCUS PYOGENES RESULTING IN REFRACTORY HYPOXEMIA

RARE CASE OF SEVERE NECROTIZING PNEUMONIA DUE TO STREPTOCOCCUS PYOGENES RESULTING IN REFRACTORY HYPOXEMIA

A FOUR-BODING FUTURE: POLYVIRAL INFECTION WITH SARS-COV-2, PARAINFLUENZA VIRUS TYPE 3, INFLUENZA A, AND ADENOVIRUS

A FOUR-BODING FUTURE: POLYVIRAL INFECTION WITH SARS-COV-2, PARAINFLUENZA VIRUS TYPE 3, INFLUENZA A, AND ADENOVIRUS

Efficacy of almitrine as a rescue therapy for refractory hypoxemia in COVID and non-COVID acute respiratory distress syndrome. A retrospective monocenter study.

Almitrine, a drug enhancing hypoxic pulmonary vasoconstriction, has been proposed as a rescue therapy for refractory hypoxemia in COVID related acute respiratory distress syndrome (C-ARDS). We aimed at investigating the response to almitrine depending on the cause of ARDS (COVID vs. non-COVID). Monocenter retrospective study from 2014 to 2021. All patients diagnosed with moderate to severe ARDS and treated with almitrine as rescue therapy for refractory hypoxemia were studied. Factor independently associated with oxygenation response to almitrine infusion were determined. Sixty patients with ARDS and treated with almitrine were analyzed, 36 (60%) due to SARS-CoV-2 infection and 24 (40%) due to other causes. Baseline PaO2/FiO2 was 78 [61-101] mmHg, 76% had at least one prone positioning before the start of almitrine infusion. Median PaO2/FiO2 increased by +38 [7-142] mmHg (+61% [10-151]) after almitrine infusion. PaO2/FiO2 increased by +134 [12-186] mmHg in non-COVID ARDS (NC-ARDS) and by +19 [8-87] mmHg in C-ARDS. The increase in PaO2/FiO2 was lower in C-ARDS than in NC-ARDS (P=0.013). In multivariable analysis, C-ARDS, non-invasive ventilation and concomitant use of norepinephrine were independently associated with a decreased oxygenation response to almitrine infusion. Our study reports a highly variable response to almitrine infusion in ARDS patients with refractory hypoxemia. Independent factors associated with a reduced oxygenation response to almitrine infusion were: COVID ARDS, concomitant use of norepinephrine, and non-invasive ventilatory strategy.

PRONE POSITIONING IN COVID-19 VS NON-COVID-19 ARDS IN THE EARLY COVID-19 PANDEMIC

PRONE POSITIONING IN COVID-19 VS NON-COVID-19 ARDS IN THE EARLY COVID-19 PANDEMIC

SEVERE IMMUNE-MEDIATED DIFFUSE ALVEOLAR HEMORRHAGE IN THE AGE OF COVID-19 AND EXTRACORPOREAL MEMBRANE OXYGENATION

SEVERE IMMUNE-MEDIATED DIFFUSE ALVEOLAR HEMORRHAGE IN THE AGE OF COVID-19 AND EXTRACORPOREAL MEMBRANE OXYGENATION

A child suffering from severe acute respiratory distress syndrome due to multiple trauma was treated with veno-veous extracorporeal membrane oxygenation with the dual lumen cannula: a case report

Veno-veous extracorporeal membrane oxygenation (VV-ECMO) has been widely used in the treatment for severe acute respiratory distress syndrome (ARDS). Up to now, the routine access to establish VV-ECMO involves two-sites single lumen cannula via femoral vein and internal jugular venous in adult and children, while few studies about the dual lumen cannula (DLC) in VV-ECMO implemented in adult and children have been reported. On December 16, 2021, an unconscious child with severe ARDS due to multiple trauma caused by fatal falling from a height was admitted to Taihe Hospital. The initial diagnosis was hemorrhagic shock, bilateral hemopneumothorax, sternal fracture, cavity organ perforation, splenic rupture, and pelvic fracture and severe ARDS. Despite mechanical ventilation, he progressed to refractory hypoxemia and was treated with VV-ECMO after successful DLC placement in the right internal jugular vein by the mobile ECMO team of intensive care unit of the Union Hospital eventually. In addition, he received endoscopic sputum aspiration, prone position ventilation, anti-infection and nutritional treatment. His oxygenation gradually improved and he was successfully weaned from ECMO after 11 days. In this case, DLC simplified the process without any related complications, suggesting that it can be safely and effectively used in the treatment of Child's severe ARDS.

RAPIDLY PROGRESSING DERMATOMYOSITIS-ASSOCIATED RESPIRATORY FAILURE SUCCESSFULLY STABILIZED WITH EXTRACORPOREAL MEMBRANE OXYGENATION

RAPIDLY PROGRESSING DERMATOMYOSITIS-ASSOCIATED RESPIRATORY FAILURE SUCCESSFULLY STABILIZED WITH EXTRACORPOREAL MEMBRANE OXYGENATION

COVID-19 in Immunocompromised Children and Adolescents.

COVID-19 in Immunocompromised Children and Adolescents.

Expert consensus on the diagnosis and treatment of severe and critical coronavirus disease 2019.

Expert consensus on the diagnosis and treatment of severe and critical coronavirus disease 2019.

Extracorporeal membrane oxygenation circuits in parallel for refractory hypoxemia in patients with COVID-19

ObjectivesRefractory hypoxemia can occur in patients with acute respiratory distress syndrome from COVID-19 despite support with venovenous (VV) extracorporeal membrane oxygenation (ECMO). Parallel ECMO circuits can be used to increase physiologic support. We report our clinical experience using ECMO circuits in parallel for select patients with persistent severe hypoxemia despite the use of a single ECMO circuit. MethodsWe performed a retrospective cohort study of all patients with COVID–19-related acute respiratory distress syndrome who received VV-ECMO with an additional circuit in parallel at Vanderbilt University Medical Center between March 1, 2020, and March 1, 2022. We report demographic characteristics and clinical characteristics including ECMO settings, mechanical ventilator settings, use of adjunctive therapies, and arterial blood gas results after initial cannulation, before and after receipt of a second ECMO circuit in parallel, and before removal of the circuit in parallel, and outcomes. ResultsOf 84 patients with COVID-19 who received VV-ECMO during the study period, 22 patients (26.2%) received a circuit in parallel. The median duration of ECMO was 40.0 days (interquartile range, 31.6-53.1 days), of which 19.0 days (interquartile range, 13.0-33.0 days) were spent with a circuit in parallel. Of the 22 patients who received a circuit in parallel, 16 (72.7%) survived to hospital discharge and 6 (27.3%) died before discharge. ConclusionsIn select patients, the additional use of an ECMO circuit in parallel can increase ECMO blood flow and improve oxygenation while allowing for lung-protective mechanical ventilation and excellent outcomes.

Application of extracorporeal membrane oxygenation in newborns with refractory hypoxemia during medical evacuation

Extracorporeal membrane oxygenation is a modern therapeutic strategy aimed to stabilize vital function in a patient suffering from severe circulatory failure and refractory hypoxia.Purpose. To describe two clinical cases of venoarterial extracorporeal membrane oxygenation in neonates with mеconium aspiration syndrome, complicated by persistent pulmonary hypertension and refractory hypoxia during medical evacuation.Material and methods. The authors performed a comprehensive analysis of the condition specifics based on clinical and instrumental work up.Results. We demonstrated that early application of venoarterial extracorporeal membrane oxygenation in neonates with meconium aspiration syndrome promotes the quickest possible stabilization and reverse of hypoxia and low cardiac output.Conclusion. Venoarterial extracorporeal membrane oxygenation in neonates with meconium aspiration syndrome and refractory hypoxemia is a life-saving procedure, that can be applied during medical evacuation by qualified medical staff.

Factors Influencing the Implementation of Prone Positioning during the COVID-19 Pandemic: A Qualitative Study.

Rationale: The adoption of prone positioning for patients with acute respiratory distress syndrome (ARDS) has historically been poor. However, in mechanically ventilated patients with coronavirus disease (COVID-19) ARDS, proning has increased. Understanding the factors influencing this change is important for further expanding and sustaining the use of prone positioning in appropriate clinical settings. Objectives: To characterize factors influencing the implementation of prone positioning in mechanically ventilated patients with COVID-19 ARDS. Methods: We conducted a qualitative study using semistructured interviews with 40 intensive care unit (ICU) team members (physicians, nurses, advanced practice providers, respiratory therapists, and physical therapists) working at two academic hospitals. We used the Consolidated Framework for Implementation Research, a widely used implementation science framework outlining important features of implementation, to structure the interview guide and thematic analysis of interviews. Results: ICU clinicians reported that during the COVID-19 pandemic, proning was viewed as standard early therapy for COVID-19 ARDS rather than salvage therapy for refractory hypoxemia. By caring for large volumes of proned patients, clinicians gained increased comfort with proning and now view proning as a low-risk, high-benefit intervention. Within ICUs, adequate numbers of trained staff members, increased team agreement around proning, and the availability of specific equipment (e.g., to limit pressure injuries) facilitated greater proning use. Hospital-level supports included proning teams, centralized educational resources specific to the management of COVID-19 (including a recommendation for prone positioning), and an electronic medical record proning order. Important implementation processes included informal dissemination of best practices through on-the-job learning and team interactions during routine bedside care. Conclusions: The implementation of prone positioning for COVID-19 ARDS took place in the context of evolving clinician viewpoints and ICU team cultures. Proning was facilitated by hospital support and buy-in and leadership from bedside clinicians. The successful implementation of prone positioning during the COVID-19 pandemic may serve as a model for the implementation of other evidence-based therapies in critical care.

REPLY: Reply to Kumar and colleagues.

The author reported no conflicts of interest.The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest.In their recent letter to the Editor, Kumar and colleagues1Kumar N. Flores A.S. Hussain N. Ganapathi A.M. Whitson B.A. Essandoh M.K. et al.Ensuring pulmonary artery patency in donor-recipient size mismatch: a collaborative challenge.J Thorac Cardiovasc Surg Tech. 2022; 15: 206-207Scopus (4) Google Scholar provided an important suggestion for additional evaluation of the pulmonary artery anastomosis after lung transplantation with transesophageal echocardiography (TEE) in the operating room. We thank Yokoyama and colleagues2Yokoyama Y. Chen-Yoshikawa T.F. Nakajima D. Ohsumi A. Date H. Various techniques for anastomosis of pulmonary arteries with size mismatch during lung transplantation.J Thorac Cardiovasc Surg Tech. 2021; 9: 192-194Scopus (7) Google Scholar for their previous article on anastomotic techniques that again highlight the importance of a technically optimal operation, which includes an unobstructed pulmonary artery anastomosis. The routine nature of thoracic transplantation might allow a suboptimal pulmonary artery anastomosis after heart or lung transplantation to go undetected as a potential cause of pulmonary graft dysfunction or donor heart right ventricular dysfunction.Kumar and colleagues' suggestion of TEE Doppler interrogation of the flow characteristics across the anastomosis after lung transplantation could provide early evidence of a technical problem. If TEE is not routinely used for lung transplant operations, the anticipation of important pulmonary artery size disparity should at least stimulate consideration with our anesthesia colleagues for insertion of a TEE probe for anastomotic examination. The author reported no conflicts of interest.The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest. The author reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest. In their recent letter to the Editor, Kumar and colleagues1Kumar N. Flores A.S. Hussain N. Ganapathi A.M. Whitson B.A. Essandoh M.K. et al.Ensuring pulmonary artery patency in donor-recipient size mismatch: a collaborative challenge.J Thorac Cardiovasc Surg Tech. 2022; 15: 206-207Scopus (4) Google Scholar provided an important suggestion for additional evaluation of the pulmonary artery anastomosis after lung transplantation with transesophageal echocardiography (TEE) in the operating room. We thank Yokoyama and colleagues2Yokoyama Y. Chen-Yoshikawa T.F. Nakajima D. Ohsumi A. Date H. Various techniques for anastomosis of pulmonary arteries with size mismatch during lung transplantation.J Thorac Cardiovasc Surg Tech. 2021; 9: 192-194Scopus (7) Google Scholar for their previous article on anastomotic techniques that again highlight the importance of a technically optimal operation, which includes an unobstructed pulmonary artery anastomosis. The routine nature of thoracic transplantation might allow a suboptimal pulmonary artery anastomosis after heart or lung transplantation to go undetected as a potential cause of pulmonary graft dysfunction or donor heart right ventricular dysfunction. Kumar and colleagues' suggestion of TEE Doppler interrogation of the flow characteristics across the anastomosis after lung transplantation could provide early evidence of a technical problem. If TEE is not routinely used for lung transplant operations, the anticipation of important pulmonary artery size disparity should at least stimulate consideration with our anesthesia colleagues for insertion of a TEE probe for anastomotic examination. Ensuring pulmonary artery patency in donor-recipient size mismatch: A collaborative challengeJTCVS TechniquesVol. 15PreviewThe vascular anastomoses of lung transplantation are a growing area of interest. Anastomosing the donor and recipient pulmonary artery (PA) segments is among the most delicate aspects of the surgery, and proper surgical technique is critical to allograft and patient survival. Obstruction of blood flow through the PA may cause graft ischemia, refractory hypoxemia, right ventricular dysfunction, and even death in affected patients.1 However, the importance of the PA anastomoses has yet to be critically examined in the lung transplant literature. Full-Text PDF Open Access

Association between obstructive sleep apnea (OSA) and atrial fibrillation (AF): A dose-response meta-analysis.

Background:Refractory hypoxemia episodes are characteristic of obstructive sleep apnea (OSA). Patients with OSA suffer from oxidative stress in all systems. Atrial fibrillation (AF) is a type of arrhythmia that may be induced by OSA. In this study, we explored the dose-response relationship between OSA and AF. Our research provides the basis for a novel approach to AF prevention.Methods:We screened four databases (PubMed, Embase, the Cochrane Library, and Web of Science) for observational studies on OSA and AF. Studies were collected from database establishment to November 2020. We performed a traditional subgroup meta-analysis. Linear and spline dose-response models were applied to assess the association between the apnea-hypopnea index, an indicator of OSA severity, and the risk of AF. Review Manager version 5.3 software and Stata 16.0 were used for the analysis.Results:Sixteen observational studies were included in the study. We excluded a study from the conventional meta-analysis. In the subgroup analysis, the odds ratios for new onset AF for no obvious reason, new onset AF after surgical operations, such as coronary artery bypass grafting, and AF after ablation treatment were 1.71 (95% CI 1.37–2.13, P < .05), 2.65 (95% CI 2.32–3.01, P < .05), and 2.93 (95% CI 2.47–3.49, P < .05), respectively. Linear dose-response meta-analysis results revealed that the risk of AF increased with increasing apnea-hypopnea index value.Conclusion:Through dose-response meta-analysis, we found a potential dose-response relationship between OSA severity and the risk of AF. This relationship should be considered in interventions aimed at AF prevention in the future.

Severe hypoxemia in a patient with right ventricular myocardial infarction and SARS-CoV-2 infection

BackgroundRefractory hypoxemia after right ventricular myocardial infarction and concomitant SARS-CoV-2 infection represents an uncommon, yet particularly challenging clinical scenario. We report a challenging diagnostic case of refractory hypoxemia due to right-to-left shunt highlighting contemporary challenges and pitfalls in acute cardiovascular care associated with the current COVID-19 pandemic.Case presentationA 52-year-old patient admitted for inferior acute myocardial infarction developed rapidly worsening hypoxemia shortly after primary percutaneous coronary intervention. RT-PCR screening for SARS-CoV-2 was positive, even though the patient had no prior symptoms. A computed tomography pulmonary angiogram excluded pulmonary embolism and showed only mild interstitial pulmonary involvement of the virus. Transthoracic echocardiogram showed severe right ventricular dysfunction and significant right-to-left shunt at the atrial level after agitated saline injection. Progressive improvement of right ventricular function allowed weaning from supplementary oxygen support. Patient was latter discharged with marked symptomatic improvement.ConclusionRefractory hypoxemia after RV myocardial infarction should be carefully addressed, even in the setting of other more common and tempting diagnoses. After exclusion of usual etiologies, right-to-left shunting at the atrial level should always be suspected, as this may avoid unnecessary and sometimes harmful interventions.

Sequential treatment of severe pneumonia with respiratory failure and its influence on respiratory mechanical parameters and hemodynamics.

BACKGROUNDThe pathophysiological characteristics of severe pneumonia complicated by respiratory failure comprise pulmonary parenchymal changes leading to ventilation imbalance, alveolar capillary injury, pulmonary edema, refractory hypoxemia, and reduced lung compliance. Prolonged hypoxia can cause acid-base balance disorder, peripheral circulatory failure, blood-pressure reduction, arrhythmia, and other adverse consequences.AIMTo investigate sequential mechanical ventilation’s effect on severe pneumonia complicated by respiratory failure. METHODSWe selected 108 patients with severe pneumonia complicated by respiratory failure who underwent mechanical ventilation between January 2018 and September 2020 at the Luhe Hospital’s Intensive Care Unit and divided them into sequential and regular groups according to a randomized trial, with each group comprising 54 patients. The sequential group received invasive and non-invasive sequential mechanical ventilation, whereas the regular group received invasive mechanical ventilation. Blood-gas parameters, hemodynamic parameters, respiratory mechanical parameters, inflammatory factors, and treatment outcomes were compared between the two groups before and after mechanical-ventilation treatment. RESULTSThe arterial oxygen partial pressure and stroke volume variation values of the sequential group at 24, 48, and 72 h of treatment were higher than those of the conventional group (P < 0.05). The carbon dioxide partial pressure value of the sequential group at 72 h of treatment and the Raw value of the treatment group at 24 and 48 h were lower than those of the conventional group (P < 0.05). The pH value of the sequential group at 24 and 72 h of treatment, the central venous pressure value of the treatment at 24 h, and the Cst value of the treatment at 24 and 48 h were higher than those of the conventional group (P < 0.05). The tidal volume in the sequential group at 24 h of treatment was higher than that in the conventional group (P < 0.05), the measured values of interleukin-6 and tumor necrosis factor-α in the sequential group at 72 h of treatment were lower than those in the conventional group (P < 0.05), and the total time of mechanical ventilation in the sequential group was shorter than that in the conventional group, with a statistically significant difference (P < 0.05).CONCLUSIONTreating severe pneumonia complicated by respiratory failure with sequential mechanical ventilation is more effective in improving respiratory system compliance, reducing inflammatory response, maintaining hemodynamic stability, and improving patient blood-gas levels; however, from this study’s perspective, it cannot reduce patient mortality.

Prone positioning for mechanically ventilated patients with coronavirus disease 2019: the experience of an Irish regional hospital intensive care unit.

BackgroundThe benefits of prone positioning in acute respiratory distress syndrome (ARDS) have been known for many years. While some controversy exists regarding whether coronavirus disease 2019 (COVID-19) pneumonia should be treated with the same therapeutic strategies as for non-COVID ARDS, the Surviving Sepsis Campaign still provide a weak recommendation to utilise prone positioning in this setting.AimsThe aims of this study are to ascertain if prone positioning improves oxygenation significantly in mechanically ventilated patients with severe COVID-19 ARDS and to describe the feasibility of frequent prone positioning in an Irish regional hospital intensive care unit (ICU) with limited prior experience.MethodsIn this retrospective, observational cohort study, we investigate if the PaO2/FiO2 ratio and ventilatory ratio improve during and following prone positioning, and whether this improvement correlates with patient baseline characteristics or survival.ResultsBetween March 2020 and 2021, 12 patients underwent prone positioning while mechanically ventilated for severe COVID ARDS. Sixty-six percent were male, mean age 60.9 (± 10.5), mean BMI 33.5 (± 6.74) and median APACHE II score on admission to ICU was 10.5 (7.25–16.3). Further, 83% were proned within 24 h of being intubated due to refractory hypoxaemia. PaO2/FiO2 ratio improved from 11.6 kPa (9.80–13.8) to 15.80 kPa (13.1–19.6) while prone, p < 0.0001.ConclusionsWe found prone positioning to be a safe method of significantly improving oxygenation in mechanically ventilated patients with severe COVID-19 ARDS. We did not find a relationship between patient baseline characteristics nor illness severity and degree of PaO2/FiO2 ratio improvement, nor did we find a relationship between degree of PaO2/FiO2 ratio improvement and survival.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11845-022-03085-9.

Comparison of acute respiratory distress syndrome in patients with COVID-19 and influenza A (H7N9) virus infection

ObjectivesWe aimed to compared the clinical features of acute respiratory distress syndrome (ARDS) induced by COVID-19 and H7N9 virus infections. MethodsClinical data of 100 patients with COVID-19 and 46 patients with H7N9 were retrospectively analyzed. ResultsElevated inflammatory indices and coagulation disorders were more common in COVID-19-ARDS group than in the H7N9-ARDS group. The median interval from illness onset to ARDS development was shorter in H7N9-ARDS. The PaO2/FiO2 level was lower in H7N9-ARDS, whereas the Sepsis-related Organ Failure Assessment score was higher in COVID-19-ARDS. The proportion of patients with disseminated intravascular coagulation and liver injury in COVID-19-ARDS and H7N9-ARDS was 45.5% versus 3.1% and 28.8% versus 50%, respectively (P <0.05). The mean interval from illness onset to death was shorter in H7N9-ARDS. A total of 59.1% patients with H7N9-ARDS died of refractory hypoxemia compared with 28.9% with COVID-19-ARDS (P = 0.014). Patients with COVID-19-ARDS were more likely to die of septic shock and multiple organ dysfunction compared with H7N9-ARDS (71.2% vs 36.4%, P = 0.005). ConclusionPatients with H7N9 were more susceptible to develop severe ARDS and showed a more acute disease course. COVID-19-ARDS was associated with severe inflammatory response and coagulation dysfunction, whereas liver injury was more common in H7N9-ARDS. The main causes of death between patients with the two diseases were different.

SARS-CoV-2 infection, pulse oximetry, and interpretive caveats.

Hypoxaemia in COVID-19 does not necessarily imply COVID pneumonia or post-COVID lung fibrosis, and the caveats of finger pulse oximetry should be remembered. Drug-induced methaemoglobinemia should be considered in individuals with unexplained cyanosis, refractory hypoxaemia, or the presence of a saturation gap. Here, we share our recent encounter of ‘spurious hypoxia’ in a patient with COVID-19 and methaemoglobinemia.