COVID-19-related organ dysfunction and management strategies on the intensive care unit: a narrative review

The importance of predictors for in-hospital COVID-19 mortality changes over one month

BACKGROUND

Risk stratification enables care providers to make the proper clinical decision for the management of patients with COVID-19 infection. We aimed to explore changes in the importance of predictors for inpatient mortality of COVID-19 over one month.

METHODS

This research was a secondary analysis of data from in-hospital patients with COVID-19 infection. Individuals were admitted to four hospitals, New York, USA. Based on the length of hospital stay, 4370 patients were categorized into three mutually exclusive interval groups, day 1, day 2-7, and day 8-28. We measured changes in the importance of twelve confirmed predictors for mortality over one month, using principal component analysis.

RESULTS

On the first day of admission, there was a higher risk for organ dysfunction, particularly in elderly patients. On day 1, serum aspartate aminotransferase and sodium were also associated with an increased risk of mortality, while normal troponin opposes in-hospital death. With time, the importance of high aspartate aminotransferase and sodium concentrations decreases, while the variable quality of high troponin levels increases. Our study suggested the importance of maintaining normal blood pressure early in the management of patients. High serum concentrations of creatinine and C-reactive protein remain poor prognostic factors throughout the 28 days. The association of age with mortality increases with the length of hospital stay.

CONCLUSION

The importance of some patients' characteristics changes with the length of hospital stay. This should be considered in developing and deploying predictive models and the management of patients with COVID-19 infection.

Effect of any form of steroids in comparison with that of other medications on the duration of olfactory dysfunction in patients with COVID-19: A systematic review of randomized trials and quasi-experimental studies

BACKGROUND

The life quality of about two-thirds of patients with COVID-19 is affected by related olfactory dysfunctions. The negative impact of olfactory dysfunction ranged from the decreased pleasure of eating to impaired quality of life. This research aimed to provide a comprehensive understanding of the effects of corticosteroid treatments by comparing that to other currently available treatments and interventions.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist's 27-point checklist was used to conduct this review. PubMed (Public/Publisher MEDLINE), PubMed Central and EMBASE (Excerpta Medica Database) databases were conveniently selected and Boolean search commands were used for a comprehensive literature search. Five core search terms were "effects of treatments", " COVID-19-related olfactory dysfunction", "corticosteroids", "treatments" and "interventions". The reporting qualities of the included studies were appraised using JBI (Joanna Briggs Institute) appraisal tools. The characteristics of the 21 experimental studies with a total sample (of 130,550) were aggregated using frequencies and percentages and presented descriptively. The main interventions and their effects on the duration of the COVID-19-related olfactory dysfunction were narratively analyzed.

RESULTS

Among patients with COVID-19, the normal functions of the olfactory lobe were about 23 days earlier to gain with the treatments of fluticasone and triamcinolone acetonide nasal spray compared with that of mometasone furoate nasal spray and oral corticosteroid. The smell loss duration was reduced by fluticasone and triamcinolone acetonide nasal spray 9 days earlier than the inflawell syrup and 16 days earlier than the lavender syrup. The nasal spray of corticosteroids ended the COVID-19-related smell loss symptoms 2 days earlier than the zinc supplementation, about 47 days earlier than carbamazepine treatment and was more effective than palmitoylethanolamide (PEA) and luteolin and omega-3 supplementations and olfactory training. Treatment with oral corticosteroid plus olfactory training significantly improved Threshold, Discrimination and Identification (TDI) scores compared with olfactory training alone. A full dose of the COVID-19 vaccination was not uncertain to reduce the COVID-19-related smell loss duration.

CONCLUSION

Corticosteroid treatment is effective in reducing the duration of COVID-19-related smell loss and olfactory training, the basic, essential and effective intervention, should be used as a combination therapy.

Ebselen and Diphenyl Diselenide Inhibit SARS-CoV-2 Replication at Non-Toxic Concentrations to Human Cell Lines

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was the causative agent of the COVID-19 pandemic, a global public health problem. Despite the numerous studies for drug repurposing, there are only two FDA-approved antiviral agents (Remdesivir and Nirmatrelvir) for non-hospitalized patients with mild-to-moderate COVID-19 symptoms. Consequently, it is pivotal to search for new molecules with anti-SARS-CoV-2 activity and to study their effects in the human immune system. Ebselen (Eb) is an organoselenium compound that is safe for humans and has antioxidant, anti-inflammatory, and antimicrobial properties. Diphenyl diselenide ((PhSe)₂) shares several pharmacological properties with Eb and is of low toxicity to mammals. Herein, we investigated Eb and (PhSe)₂ anti-SARS-CoV-2 activity in a human pneumocytes cell model (Calu-3) and analyzed their toxic effects on human peripheral blood mononuclear cells (PBMCs). Both compounds significantly inhibited the SARS-CoV-2 replication in Calu-3 cells. The EC₅₀ values for Eb and (PhSe)₂ after 24 h post-infection (hpi) were 3.8 µM and 3.9 µM, respectively, and after 48 hpi were 2.6 µM and 3.4 µM. These concentrations are safe for non-infected cells, since the CC₅₀ values found for Eb and (PhSe)₂ on Calu-3 were greater than 200 µM. Importantly, the concentration rates tested on viral replication were not toxic to human PBMCs. Therefore, our findings reinforce the efficacy of Eb and demonstrate (PhSe)₂ as a new candidate to be tested in future trials against SARS-CoV-2 infection/inflammation conditions.

Bronchoscopy-guided percutaneous tracheostomy during the COVID-19 pandemic

BACKGROUND

Assessment of the efficacy and complications associated with performing bronchoscopy-guided percutaneous tracheostomy in COVID-19 and non-COVID-19 patients.

METHODS

Prospective observational study conducted between March of 2020 and February of 2022. All adult patients who underwent elective bronchoscopy-guided percutaneous tracheostomy were included. The efficacy of the procedure was evaluated based either on the success rate in the execution or on the need for conversion to open technique. Percutaneous tracheostomy-related complications were registered during the procedure. We performed 6-month follow-up for identifying late complications.

RESULTS

During the study period, 312 bronchoscopy-guided percutaneous tracheostomies were analyzed. One hundred and eighty-three were performed in COVID-19 patients and 129 among non-COVID-19 patients. Overall, 64.1% (200) of patients were male, with a median age of 66 (interquartile range 54-74), and 65% (205) presented at least 1 comorbidity. Overall, oxygen desaturation was the main complication observed (20.8% [65]), being more frequent in the COVID-19 group occurring in 27.3% (50) with a statistically significant difference versus the non-COVID-19 patients' group (11.6% [15]); P < .01). Major complications such as hypotension, arrhythmias, and pneumothorax were more frequently observed among COVID-19 patients as well but with no significant differences. Percutaneous tracheostomy could be executed quickly and satisfactorily in all the patients with no need for conversion to the open technique. Likewise, no suspension of the procedure was required in any case. During 6-month follow-up, we found an incidence of 0.96% (n = 3) late complications, 2 tracheal granulomas, and 1 ostomal infection.

CONCLUSION

Bronchoscopy-guided percutaneous tracheostomy can be considered an effective and safe procedure in COVID-19 patients. Nevertheless, it is highly remarkable that in the series under study, a great number of COVID-19 patients presented oxygen desaturation during the procedure.

FACTORS AFFECTING PROGNOSIS AND MORTALITY IN SEVERE COVID-19 PNEUMONIA PATIENTS

Fatality rate in coronavirus disease 2019 (COVID-19) cases has been reported to be 3.4% worldwide. The aim of this study was to evaluate the factors that determine prognosis and mortality in severe COVID-19 pneumonia patients. Eighty adult patients with severe COVID-19 pneumonia hospitalized and monitored at Izzet Baysal State Hospital (Bolu, Turkey) between August and November 2020 were included in this retrospective single-center study. Demographic and laboratory data, severity of radiological involvement, comorbidities, agents used in treatment, and clinical results were recorded, and data were grouped as survivors and non-survivors. The mean patient age was 67.8±12.6 years. There were 59 (73.8%) male patients. Comorbid diseases were present in 53 (66.3%) patients. There was no significant relationship between patient age, gender, smoking status or presence of comorbidity and mortality (p>0.05). The variables such as pulmonary involvement above 50%, intubation, or ferritin (>434.8 µg/L), troponin I (>14.05 ng/L) and procalcitonin (>0.125 ng/mL) as the sole variables of laboratory data were found to have significant relationship with increased mortality (p<0.05). Mortality was significantly higher in patients using steroid pulse therapy + tocilizumab, steroid pulse therapy + hydroxychloroquine, or solely steroid pulse therapy, while it was significantly lower in patients receiving azithromycin therapy and those in the plasma + steroid pulse therapy group. The severity of pulmonary involvement, intubation, and increase in inflammation markers such as ferritin, troponin and procalcitonin were found to be significantly associated with mortality (p<0.05). Treatment approaches with azithromycin and plasma + steroid pulse therapy were found to reduce mortality.

Hematological Parameters and Procalcitonin as Discriminants between Bacterial Pneumonia-Induced Sepsis and Viral Sepsis Secondary to COVID-19: A Retrospective Single-Center Analysis

Bacterial and viral sepsis induce alterations of all hematological parameters and procalcitonin is used as a biomarker of infection and disease severity. Our aim was to study the hematological patterns associated with pulmonary sepsis triggered by bacteria and Severe Acute Respiratory Syndrome-Coronavirus-type-2 (SARS-CoV-2) and to identify the discriminants between them. We performed a retrospective, observational study including 124 patients with bacterial sepsis and 138 patients with viral sepsis. Discriminative ability of hematological parameters and procalcitonin between sepsis types was tested using receiver operating characteristic (ROC) analysis. Sensitivity (Sn%), specificity (Sp%), positive and negative likelihood ratios were calculated for the identified cut-off values. Patients with bacterial sepsis were older than patients with viral sepsis (p < 0.001), with no differences regarding gender. Subsequently to ROC analysis, procalcitonin had excellent discriminative ability for bacterial sepsis diagnosis with an area under the curve (AUC) of 0.92 (cut-off value of >1.49 ng/mL; Sn = 76.6%, Sp = 94.2%), followed by RDW% with an AUC = 0.87 (cut-off value >14.8%; Sn = 80.7%, Sp = 85.5%). Leukocytes, monocytes and neutrophils had good discriminative ability with AUCs between 0.76-0.78 (p < 0.001), while other hematological parameters had fair or no discriminative ability. Lastly, procalcitonin value was strongly correlated with disease severity in both types of sepsis (p < 0.001). Procalcitonin and RDW% had the best discriminative ability between bacterial and viral sepsis, followed by leukocytes, monocytes and neutrophils. Procalcitonin is a marker of disease severity regardless of sepsis type.

Early use of airway pressure release ventilation in acute respiratory distress syndrome induced by coronavirus disease 2019: a case report

BACKGROUND

Coronavirus disease 2019 is a highly transmissible and pathogenic viral infection caused by severe acute respiratory syndrome coronavirus 2, a novel coronavirus that was identified in early January 2020 in Wuhan, China, and has become a pandemic disease worldwide. The symptoms of coronavirus disease 2019 range from asymptomatic to severe respiratory failure. In moderate and severe cases, oxygen therapy is needed. In severe cases, high-flow nasal cannula, noninvasive ventilation, and invasive mechanical ventilation are needed. Many ventilation methods in mechanical ventilation can be used, but not all are suitable for coronavirus disease 2019 patients. Airway pressure release ventilation, which is one of the mechanical ventilation methods, can be considered for patients with moderate-to-severe acute respiratory distress syndrome. It was found that oxygenation in the airway pressure release ventilation method was better than in the conventional method. How about airway pressure release ventilation in coronavirus disease 2019 patients? We report a case of confirmed coronavirus disease 2019 in which airway pressure release ventilation mode was used.

CASE PRESENTATION

In this case study, we report a 74-year-old Chinese with a history of hypertension and uncontrolled diabetes mellitus type 2. He came to our hospital with the chief complaint of difficulty in breathing. He was fully awake with an oxygen saturation of 82% on room air. The patient was admitted and diagnosed with severe coronavirus disease 2019, and he was given a nonrebreathing mask at 15 L per minute, and oxygen saturation went back to 95%. After a few hours with a nonrebreathing mask, his condition worsened. On the third day after admission, saturation went down despite using noninvasive ventilation. We decided to intubate the patient and used airway pressure release ventilation mode. Finally, after 14 days of being intubated, the patient could be extubated and discharged after 45 days of hospitalization.

CONCLUSION

Early use of airway pressure release ventilation may be considered as one of the ventilation strategies to treat severe coronavirus disease 2019 acute respiratory distress syndrome. Although reports on airway pressure release ventilation and protocols on its initiation and titration methods are limited, it may be worthwhile to consider, given its known ability to maximize alveolar recruitment, preserve alveolar epithelial integrity, and surfactant, all of which are crucial for handling the "fragile" lungs of coronavirus disease 2019 patients.

Characteristics and outcomes of parturients with COVID-19, admitted to a critical care unit: A single-center retrospective observational study

Background

Data on outcomes of coronavirus disease 2019 (COVID-19) in pregnancy are scarce, although they represent a unique physiological state affecting both the mother and child. We present collated data from a tertiary care center in North India, encompassing the outcome, clinical characteristics, and management of these patients.

Materials and Methods

Parturients ≥ 18 years old, with COVID-19 reverse transcriptase polymerase chain reaction positive for severe acute respiratory syndrome coronavirus 2, requiring intensive care unit (ICU) admission at a tertiary care hospital were included. Data were retrospectively collected from April 2020 to November 2021.

Results

In all, 26 parturients were admitted to ICU with COVID-19. Five patients were admitted during the first wave, and all were asymptomatic. Twenty-one patients presented during the second wave (March 2021 onward), among which four were asymptomatic and 17 symptomatic (all with severe pneumonia). Three patients presented in the second trimester, all with critical disease, out of which one did not survive. Two patients had twin gestation, and others were singleton pregnancies. Seven patients (27%) were primigravida, and five patients (19.2%) had more than third pregnancy. Twenty critically ill women (77%) delivered during the hospital stay. Six patients died during the second wave, and four deaths (66.7%) were because of COVID-19 acute respiratory distress syndrome (ARDS).

Conclusions

The number of admissions and mortality related to COVID-19 ARDS was higher in the second wave than in the first. We report the safe use of remdesivir and tocilizumab in our patients.

Chest wall loading during supine and prone position in patients with COVID-19 ARDS: effects on respiratory mechanics and gas exchange

Background

Recent reports of patients with severe, late-stage COVID-19 ARDS with reduced respiratory system compliance described paradoxical decreases in plateau pressure and increases in respiratory system compliance in response to anterior chest wall loading. We aimed to assess the effect of chest wall loading during supine and prone position in ill patients with COVID-19-related ARDS and to investigate the effect of a low or normal baseline respiratory system compliance on the findings.

Methods

This is a single-center, prospective, cohort study in the intensive care unit of a COVID-19 referral center. Consecutive mechanically ventilated, critically ill patients with COVID-19-related ARDS were enrolled and classified as higher (≥ 40 ml/cmH₂O) or lower respiratory system compliance (< 40 ml/cmH₂O). The study included four steps, each lasting 6 h: Step 1, supine position, Step 2, 10-kg continuous chest wall compression (supine + weight), Step 3, prone position, Step 4, 10-kg continuous chest wall compression (prone + weight). The mechanical properties of the respiratory system, gas exchange and alveolar dead space were measured at the end of each step.

Results

Totally, 40 patients were enrolled. In the whole cohort, neither oxygenation nor respiratory system compliance changed between supine and supine + weight; both increased during prone positioning and were unaffected by chest wall loading in the prone position. Alveolar dead space was unchanged during all the steps. In 16 patients with reduced compliance, PaO₂/FiO₂ significantly increased from supine to supine + weight and further with prone and prone + weight (107 ± 15.4 vs. 120 ± 18.5 vs. 146 ± 27.0 vs. 159 ± 30.4, respectively; p < 0.001); alveolar dead space decreased from both supine and prone position after chest wall loading, and respiratory system compliance significantly increased from supine to supine + weight and from prone to prone + weight (23.9 ± 3.5 vs. 30.9 ± 5.7 and 31.1 ± 5.7 vs. 37.8 ± 8.7 ml/cmH₂O, p < 0.001). The improvement was higher the lower the baseline compliance.

Conclusions

Unlike prone positioning, chest wall loading had no effects on respiratory system compliance, gas exchange or alveolar dead space in an unselected cohort of critically ill patients with C-ARDS. Only patients with a low respiratory system compliance experienced an improvement, with a higher response the lower the baseline compliance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04141-7.

COVID-19 in cancer patients with diabetes in Pakistan: Clinical features and management

Background

Diabetes and cancer are the leading causes of mortality all over the world. Infectious diseases are more common and/or life-threatening in patients with diabetes. Cancer patients with diabetes are individuals that are more susceptible to the current COVID-19 pandemic. We investigated the clinical features of survivor and non-survivor COVID-19-infected cancer patients with diabetes.

Patients and Methods

We did a retrospective study of 43 diabetic cancer patients with PCR-confirmed COVID-19 infection from Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan between March 03, 2020, and May 18, 2021. These patients either were discharged from the hospital or had died by Jun 16, 2021. Clinicopathological and radiological features were compared between survivors and non-survivors by fisher’s exact test and chi-square test.

Results

Forty-three diabetic cancer patients with SARS-CoV-2 infection were enrolled and the majority were males 26 (60.5%). The overall mean age was 61.67 ± 11.80. 39 (90.7%) had solid tumors and 3 (7.0%) had hematological malignancies. Fever (74.4%) and dyspnea (58.1%) were the most common symptoms. Complications were reported in 36 (83.7%) patients; during the course of the disease. Additionally, all the deceased patients (n=15) had acquired the complications. 11 (25.6%) patients were admitted to an intensive care unit (ICU). Furthermore, 29 (67.4%) out of 43 patients showed abnormal features in the radiological findings. We found significantly elevated levels of C-reactive protein (P=0.005), serum lactate (P=0.01), albumin (P=0.02), alkaline phosphate (P=0.03), and neutrophil count (P=0.04) in the non-survivors as compared to the survivors.

Conclusion

Cancer patients with diabetes are a vulnerable population in the current pandemic. Identifying how diabetes in cancer patients affects the severity of SARS-CoV-2 infection is crucial for the clinical management of these patients. Rigorous scrutiny of clinicopathological features of COVID-19 infected cancer patients with diabetes especially values of C-reactive protein, lactate, albumin, alkaline phosphate, neutrophils, and regular monitoring of blood glucose levels may play a critical role in the outcome of the disease.

Subcutaneous Enoxaparin for Systemic Anticoagulation of COVID-19 Patients During Extracorporeal Life Support

Background

Extracorporeal membrane oxygenation, with an inherent requirement for anticoagulation to avoid circuit thrombosis, is a key element in the treatment of respiratory failure associated with COVID-19. Anticoagulation remains challenging, the standard of care being intravenous continuous administration of unfractionated heparin. Yet regimens vary. Some intensive care units in our center have successfully used enoxaparin subcutaneously in recent years and throughout the pandemic.

Methods

We retrospectively analyzed adult COVID-19 patients with respiratory failure who had been systemically anticoagulated using either enoxaparin or unfractionated heparin. The choice of anticoagulant therapy was based on the standard of the intensive care unit. Defined thromboembolic and hemorrhagic events were analyzed as study endpoints.

Results

Of 98 patients, 62 had received enoxaparin and 36 unfractionated heparin. All hazard ratios for the thromboembolic (3.43; 95% CI: 1.08–10.87; p = 0.04), hemorrhagic (2.58; 95% CI: 1.03–6.48; p = 0.04), and composite (2.86; 95% CI: 1.41–5.92; p = 0.007) endpoints favored enoxaparin, whose efficient administration was verified by peak levels of anti-factor Xa (median: 0.45 IU ml⁻¹; IQR: 0.38; 0.56). Activated partial thromboplastin time as well as thrombin time differed significantly (both p<0.001) between groups mirroring the effect of unfractionated heparin.

Conclusions

This study demonstrates the successful use of subcutaneous enoxaparin for systemic anticoagulation in patients with COVID-19 during extracorporeal membrane oxygenation. Our findings are to be confirmed by future prospective, randomized, controlled trials.

Development and Internal Validation of a New Prognostic Model Powered to Predict 28-Day All-Cause Mortality in ICU COVID-19 Patients-The COVID-SOFA Score

Background: The sequential organ failure assessment (SOFA) score has poor discriminative ability for death in severely or critically ill patients with Coronavirus disease 2019 (COVID-19) requiring intensive care unit (ICU) admission. Our aim was to create a new score powered to predict 28-day mortality. Methods: Retrospective, observational, bicentric cohort study including 425 patients with COVID-19 pneumonia, acute respiratory failure and SOFA score ≥ 2 requiring ICU admission for ≥72 h. Factors with independent predictive value for 28-day mortality were identified after stepwise Cox proportional hazards (PH) regression. Based on the regression coefficients, an equation was computed representing the COVID-SOFA score. Discriminative ability was tested using receiver operating characteristic (ROC) analysis, concordance statistics and precision-recall curves. This score was internally validated. Results: Median (Q1−Q3) age for the whole sample was 64 [55−72], with 290 (68.2%) of patients being male. The 28-day mortality was 54.58%. After stepwise Cox PH regression, age, neutrophil-to-lymphocyte ratio (NLR) and SOFA score remained in the final model. The following equation was computed: COVID-SOFA score = 10 × [0.037 × Age + 0.347 × ln(NLR) + 0.16 × SOFA]. Harrell’s C-index for the COVID-SOFA score was higher than the SOFA score alone for 28-day mortality (0.697 [95% CI; 0.662−0.731] versus 0.639 [95% CI: 0.605−0.672]). Subsequently, the prediction error rate was improved up to 16.06%. Area under the ROC (AUROC) was significantly higher for the COVID-SOFA score compared with the SOFA score for 28-day mortality: 0.796 [95% CI: 0.755−0.833] versus 0.699 [95% CI: 0.653−0.742, p < 0.001]. Better predictive value was observed with repeated measurement at 48 h after ICU admission. Conclusions: The COVID-SOFA score is better than the SOFA score alone for 28-day mortality prediction. Improvement in predictive value seen with measurements at 48 h after ICU admission suggests that the COVID-SOFA score can be used in a repetitive manner. External validation is required to support these results.

Inhaled Sedation for Invasively Ventilated COVID-19 Patients: A Systematic Review

Background: Volatile anesthetics were used as sedative agents in COVID-19 (Coronavirus Disease 2019) invasively ventilated patients for their potentially beneficial pharmacological effects and due to the temporary shortages of intravenous agents during the pandemic crisis. Methods: Online databases (PubMed, EMBASE, The Cochrane Central Register of Controlled Trial) and the “clinicaltrials.gov” website were searched for studies reporting the use of isoflurane, sevoflurane or desflurane. Results: We identified three manuscripts describing the beneficial effects of isoflurane on 41 COVID-19 patients with acute respiratory distress syndrome (ARDS) in Germany (n = 2) and in the USA (n = 1), in terms of reduction in the use of opioids and other sedatives. We also found a case report of two patients with transient nephrogenic diabetes insipidus, which started after 6 and 8 days of sevoflurane sedation. We identified two randomized controlled trials (RCTs; 92 patients overall), two observational studies (238 patients) on the use of volatile anesthetics in COVID-19 patients that were completed but not yet published, and one RCT interrupted for a low recruitment ratio (19 patients) and thus not published. We also identified five ongoing RCTs on the use of inhaled sedation in ARDS, which are also likely to be recruiting COVID-19 patients and which have currently enrolled a total of >1643 patients. Conclusion: Isoflurane was the most frequently used volatile agent in COVID-19 patients and allowed a reduction in the use of other sedative and analgesic drugs. Randomized evidence is building up and will be useful to confirm or challenge these findings.

Global Research Status of Multiple Organ Dysfunction Syndrome During 2001-2021: A 20-Year Bibliometric Analysis

Background

Multiple Organ Dysfunction Syndrome (MODS) is a major cause of high morbidity and mortality among patients in intensive care units (ICU). Although numerous basic and clinical researches on MODS have been conducted, there is still a long way to go to prevent patients from entering this stage. To our knowledge, no bibliometric analyses of MODS have been reported, this study, therefore, was conducted to reveal MODS research status and trends during 2001–2021.

Methods

All relevant literature covering MODS during 2001–2021 were extracted from Web of Science. An online analysis platform of literature metrology was used to analyze the publication trends. VOSviewer software was used to collect and analyze the keywords and research hotspots related to MODS.

Results

As of July 31, 2021, a total of 994 MODS-related articles from 2001 to 2021 were identified. The United States accounted for the largest number of publications (31.1%), followed by China and Germany, with 186 and 75 publications, respectively. Among all the institutions, the University of Pittsburgh published the most papers related to MODS (21). Critical Care Medicine published the most papers in this field (106). Professor Moore EE, who had the most citation frequency (1847), made great achievements in MODS research. Moreover, analysis of the keywords identified three MODS research hotspot clusters: “mechanism-related research,” “clinical research,” and “diagnostic research.”

Conclusions

The United States maintained a top position worldwide and made the most outstanding contribution in the MODS field. In terms of publication, China was next only to the United States, but there was a disproportion between the quantity of publications and citation frequency. The institution University of Pittsburgh and journal Critical Care Medicine represent the highest level of research in this field. During the 20 years from 2001 to 2021, basic MODS research has been in-depth yet progressed relatively slowly recently, but the outbreak of COVID-19 has to some extent set off an upsurge of clinical research in MODS field.

Optimising respiratory support for early COVID-19 pneumonia: a computational modelling study

Background

Optimal respiratory support in early COVID-19 pneumonia is controversial and remains unclear. Using computational modelling, we examined whether lung injury might be exacerbated in early COVID-19 by assessing the impact of conventional oxygen therapy (COT), high-flow nasal oxygen therapy (HFNOT), continuous positive airway pressure (CPAP), and noninvasive ventilation (NIV).

Methods

Using an established multi-compartmental cardiopulmonary simulator, we first modelled COT at a fixed FiO₂ (0.6) with elevated respiratory effort for 30 min in 120 spontaneously breathing patients, before initiating HFNOT, CPAP, or NIV. Respiratory effort was then reduced progressively over 30-min intervals. Oxygenation, respiratory effort, and lung stress/strain were quantified. Lung-protective mechanical ventilation was also simulated in the same cohort.

Results

HFNOT, CPAP, and NIV improved oxygenation compared with conventional therapy, but also initially increased total lung stress and strain. Improved oxygenation with CPAP reduced respiratory effort but lung stress/strain remained elevated for CPAP >5 cm H₂O. With reduced respiratory effort, HFNOT maintained better oxygenation and reduced total lung stress, with no increase in total lung strain. Compared with 10 cm H₂O PEEP, 4 cm H₂O PEEP in NIV reduced total lung stress, but high total lung strain persisted even with less respiratory effort. Lung-protective mechanical ventilation improved oxygenation while minimising lung injury.

Conclusions

The failure of noninvasive ventilatory support to reduce respiratory effort may exacerbate pulmonary injury in patients with early COVID-19 pneumonia. HFNOT reduces lung strain and achieves similar oxygenation to CPAP/NIV. Invasive mechanical ventilation may be less injurious than noninvasive support in patients with high respiratory effort.

Pathophysiology of coronavirus-19 disease acute lung injury

PURPOSE OF REVIEW

More than 230 million people have tested positive for severe acute respiratory syndrome-coronavirus-2 infection globally by September 2021. The infection affects primarily the function of the respiratory system, where ∼20% of infected individuals develop coronavirus-19 disease (COVID-19) pneumonia. This review provides an update on the pathophysiology of the COVID-19 acute lung injury.

RECENT FINDINGS

In patients with COVID-19 pneumonia admitted to the intensive care unit, the PaO2/FiO2 ratio is typically <26.7 kPa (200 mmHg), whereas lung volume appears relatively unchanged. This hypoxaemia is likely determined by a heterogeneous mismatch of pulmonary ventilation and perfusion, mainly associated with immunothrombosis, endothelialitis and neovascularisation. During the disease, lung weight, elastance and dead space can increase, affecting respiratory drive, effort and dyspnoea. In some severe cases, COVID-19 pneumonia may lead to irreversible pulmonary fibrosis.

SUMMARY

This review summarises the fundamental pathophysiological features of COVID-19 in the context of the respiratory system. It provides an overview of the key clinical manifestations of COVID-19 pneumonia, including gas exchange impairment, altered pulmonary mechanics and implications of abnormal chemical and mechanical stimuli. It also critically discusses the clinical implications for mechanical ventilation therapy.

Efficacy of the use of mefenamic acid combined with standard medical care vs. standard medical care alone for the treatment of COVID‑19: A randomized double‑blind placebo‑controlled trial

Mefenamic acid is a non‑steroidal anti‑inflammatory drug exhibiting a wide range of anti‑inflammatory, antipyretic, analgesic and probable antiviral activities. The present study evaluated the efficacy of treatment with mefenamic acid combined with standard medical care vs. standard medical care plus a placebo in ambulatory patients with coronavirus disease 2019 (COVID‑19; nasal/oropharyngeal swabs reverse transcription‑PCR test results positive for severe acute respiratory syndrome coronavirus 2). The present study is a phase II prospective, two‑arm, parallel‑group, randomized, double‑blind placebo‑controlled clinical trial which analyzed 36 patients. Two aspects were evaluated during the 14‑day follow‑up period: i) The time for reaching a patient acceptable symptom state (PASS), and ii) the last day of each COVID‑19 symptom presentation. Adverse effects were evaluated. The clinical severity for all the patients in the study was mild (88.9%) and moderate (11.1%). The control (placebo) group achieved PASS on day 8.0±1.3, compared with day 4.4±0.8 in the mefenamic acid group (P=0.020, Kaplan‑Meier analyses using log‑rank tests). Patients that received mefenamic acid plus standard medical care had a ~16‑fold higher probability of achieving PASS on day 8 (adjusted RR, 15.57; 95% CI, 1.22‑198.71; P=0.035), compared with the placebo plus standard medical care group. All symptoms lasted for fewer days in the mefenamic acid group, compared with the placebo group; however, only the symptoms of headache (P=0.008), retro‑orbital eye pain (P=0.049), and sore throat (P=0.029) exhibited statistically significant differences. The experimental treatment produced no severe adverse effects. On the whole, the present study demonstrates that the administration of mefenamic acid markedly reduced the symptomatology and time to reach PASS in ambulatory patients with COVID‑19. Due to its probable antiviral effects and potent anti‑inflammatory mechanisms, mefenamic acid may prove to be useful in the treatment of COVID‑19, in combination with other drugs, including the new antivirals (remdesivir, molnupiravir, or favipiravir). However, future studies are also required to confirm these findings.

The Safety of Continuous Infusion Propofol in Mechanically Ventilated Adults With Coronavirus Disease 2019

BACKGROUND

Propofol is commonly used to achieve ventilator synchrony in critically ill patients with coronavirus disease 2019 (COVID-19), yet its safety in this patient population is unknown.

OBJECTIVE

To evaluate the safety, in particular the incidence of hypertriglyceridemia, of continuous infusion propofol in patients with COVID-19.

METHODS

This was a retrospective study at 1 academic medical center and 1 affiliated teaching hospital in New York City. Adult, critically ill patients with COVID-19 who received continuous infusion propofol were included. Patients who received propofol for <12 hours, were transferred from an outside hospital while on mechanical ventilation, or did not have a triglyceride concentration obtained during the infusion were excluded.

RESULTS

A total of 252 patients were included. Hypertriglyceridemia (serum triglyceride concentration ≥ 400 mg/dL) occurred in 38.9% of patients after a median cumulative dose of 4307 mg (interquartile range [IQR], 2448-9431 mg). The median time to triglyceride elevation was 3.8 days (IQR, 1.9-9.1 days). In the multivariable regression analysis, obese patients had a significantly greater odds of hypertriglyceridemia (odds ratio = 1.87; 95% CI = 1.10, 3.21). There was no occurrence of acute pancreatitis. The incidence of possible propofol-related infusion syndrome was 3.2%.

CONCLUSION AND RELEVANCE

Hypertriglyceridemia occurred frequently in patients with COVID-19 who received propofol but did not lead to acute pancreatitis. Elevated triglyceride concentrations occurred more often and at lower cumulative doses than previously reported in patients without COVID-19. Application of these data may aid in optimal monitoring for serious adverse effects of propofol in patients with COVID-19.

SARS-CoV-2 new variants: Characteristic features and impact on the efficacy of different vaccines

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its new variants reported in different countries have posed a serious threat to human health and social fabrics worldwide. In addition, these new variants hindered the efforts of vaccines and other therapeutic developments. In this review article, we explained the emergence of new variants of SARS-CoV-2, their transmission risk, mortality rate, and, more importantly, the impact of each new variant on the efficacy of the developed vaccines reported in different literature and findings. The literature reported that with the emergence of new variants, the efficacy of different vaccines is declined, hospitalization and the risk of reinfection is increased. The reports concluded that the emergence of a variant that entirely evades the immune response triggered by the vaccine is improbable. The emergence of new variants and reports of re-infections are creating a more distressing situation and therefore demands further investigation to formulate an effective therapeutic strategy.

Mechanical ventilation in COVID-19: A physiological perspective

New Findings

What is the topic of this review?

This review presents the fundamental concepts of respiratory physiology and pathophysiology, with particular reference to lung mechanics and the pulmonary phenotype associated with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection and subsequent coronavirus disease 2019 (COVID‐19) pneumonia.

What advances does it highlight?

The review provides a critical summary of the main physiological aspects to be considered for safe and effective mechanical ventilation in patients with severe COVID‐19 in the intensive care unit.

Abstract

Severe respiratory failure from coronavirus disease 2019 (COVID‐19) pneumonia not responding to non‐invasive respiratory support requires mechanical ventilation. Although ventilation can be a life‐saving therapy, it can cause further lung injury if airway pressure and flow and their timing are not tailored to the respiratory system mechanics of the individual patient. The pathophysiology of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection can lead to a pattern of lung injury in patients with severe COVID‐19 pneumonia typically associated with two distinct phenotypes, along a temporal and pathophysiological continuum, characterized by different levels of elastance, ventilation‐to‐perfusion ratio, right‐to‐left shunt, lung weight and recruitability. Understanding the underlying pathophysiology, duration of symptoms, radiological characteristics and lung mechanics at the individual patient level is crucial for the appropriate choice of mechanical ventilation settings to optimize gas exchange and prevent further lung injury. By critical analysis of the literature, we propose fundamental physiological and mechanical criteria for the selection of ventilation settings for COVID‐19 patients in intensive care units. In particular, the choice of tidal volume should be based on obtaining a driving pressure < 14 cmH₂O, ensuring the avoidance of hypoventilation in patients with preserved compliance and of excessive strain in patients with smaller lung volumes and lower lung compliance. The level of positive end‐expiratory pressure (PEEP) should be informed by the measurement of the potential for lung recruitability, where patients with greater recruitability potential may benefit from higher PEEP levels. Prone positioning is often beneficial and should be considered early. The rationale for the proposed mechanical ventilation settings criteria is presented and discussed.

Comparison of isoflurane and propofol sedation in critically ill COVID-19 patients-a retrospective chart review

Purpose

In this retrospective study, we compared inhaled sedation with isoflurane to intravenous propofol in invasively ventilated COVID-19 patients with ARDS (Acute Respiratory Distress Syndrome).

Methods

Charts of all 20 patients with COVID-19 ARDS admitted to the ICU of a German University Hospital during the first wave of the pandemic between 22/03/2020 and 21/04/2020 were reviewed. Among screened 333 days, isoflurane was used in 97 days, while in 187 days, propofol was used for 12 h or more. The effect and dose of these two sedatives were compared. Mixed sedation days were excluded.

Results

Patients’ age (median [interquartile range]) was 64 (60–68) years. They were invasively ventilated for 36 [21–50] days. End-tidal isoflurane concentrations were high (0.96 ± 0.41 Vol %); multiple linear regression yielded the ratio (isoflurane infusion rate)/(minute ventilation) as the single best predictor. Infusion rates were decreased under ECMO (3.5 ± 1.4 versus 7.1 ± 3.2 ml∙h⁻¹; p < 0.001). In five patients, the maximum recommended dose of propofol of 4 mg∙hour⁻¹∙kg⁻¹ABW was exceeded on several days. On isoflurane compared to propofol days, neuro-muscular blocking agents (NMBAs) were used less frequently (11% versus 21%; p < 0.05), as were co-sedatives (7% versus 31%, p < 0.001); daily opioid doses were lower (720 [720–960] versus 1080 [720–1620] mg morphine equivalents, p < 0.001); and RASS scores indicated deeper levels of sedation (− 4.0 [− 4.0 to − 3.0] versus − 3.0 [− 3.6 to − 2.5]; p < 0.01).

Conclusion

Isoflurane provided sufficient sedation with less NMBAs, less polypharmacy and lower opioid doses compared to propofol. High doses of both drugs were needed in severely ill COVID-19 patients.

COVID-19 Pathology on Various Organs and Regenerative Medicine and Stem Cell-Based Interventions

Severe acute respiratory syndrome-coronavirus 2, a novel betacoronavirus, has caused the global outbreak of a contagious infection named coronavirus disease-2019. Severely ill subjects have shown higher levels of pro-inflammatory cytokines. Cytokine storm is the term that can be used for a systemic inflammation leading to the production of inflammatory cytokines and activation of immune cells. In coronavirus disease-2019 infection, a cytokine storm contributes to the mortality rate of the disease and can lead to multiple-organ dysfunction syndrome through auto-destructive responses of systemic inflammation. Direct effects of the severe acute respiratory syndrome associated with infection as well as hyperinflammatory reactions are in association with disease complications. Besides acute respiratory distress syndrome, functional impairments of the cardiovascular system, central nervous system, kidneys, liver, and several others can be mentioned as the possible consequences. In addition to the current therapeutic approaches for coronavirus disease-2019, which are mostly supportive, stem cell-based therapies have shown the capacity for controlling the inflammation and attenuating the cytokine storm. Therefore, after a brief review of novel coronavirus characteristics, this review aims to explain the effects of coronavirus disease-2019 cytokine storm on different organs of the human body. The roles of stem cell-based therapies on attenuating cytokine release syndrome are also stated.

Pathophysiological Processes Underlying the High Prevalence of Deep Vein Thrombosis in Critically Ill COVID-19 Patients

Coronavirus disease 2019 (COVID-19) predisposes to deep vein thrombosis (DVT) and pulmonary embolism (PE) particularly in mechanically ventilated adults with severe pneumonia. The extremely high prevalence of DVT in the COVID-19 patients hospitalized in the intensive care unit (ICU) has been established between 25 and 84% based on studies including systematic duplex ultrasound of the lower limbs when prophylactic anticoagulation was systematically administrated. DVT prevalence has been shown to be markedly higher than in mechanically ventilated influenza patients (6–8%). Unusually high inflammatory and prothrombotic phenotype represents a striking feature of COVID-19 patients, as reflected by markedly elevated reactive protein C, fibrinogen, interleukin 6, von Willebrand factor, and factor VIII. Moreover, in critically ill patients, venous stasis has been associated with the prothrombotic phenotype attributed to COVID-19, which increases the risk of thrombosis. Venous stasis results among others from immobilization under muscular paralysis, mechanical ventilation with high positive end-expiratory pressure, and pulmonary microvascular network injuries or occlusions. Venous return to the heart is subsequently decreased with increase in central and peripheral venous pressures, marked proximal and distal veins dilation, and drops in venous blood flow velocities, leading to a spontaneous contrast “sludge pattern” in veins considered as prothrombotic. Together with endothelial lesions and hypercoagulability status, venous stasis completes the Virchow triad and considerably increases the prevalence of DVT and PE in critically ill COVID-19 patients, therefore raising questions regarding the optimal doses for thromboprophylaxis during ICU stay.

COVID-19-associated acute respiratory distress syndrome (CARDS): Current knowledge on pathophysiology and ICU treatment - A narrative review

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces coronavirus-19 disease (COVID-19) and is a major health concern. Following two SARS-CoV-2 pandemic “waves,” intensive care unit (ICU) specialists are treating a large number of COVID19-associated acute respiratory distress syndrome (ARDS) patients. From a pathophysiological perspective, prominent mechanisms of COVID19-associated ARDS (CARDS) include severe pulmonary infiltration/edema and inflammation leading to impaired alveolar homeostasis, alteration of pulmonary physiology resulting in pulmonary fibrosis, endothelial inflammation (endotheliitis), vascular thrombosis, and immune cell activation.

Although the syndrome ARDS serves as an umbrella term, distinct, i.e., CARDS-specific pathomechanisms and comorbidities can be noted (e.g., virus-induced endotheliitis associated with thromboembolism) and some aspects of CARDS can be considered ARDS “atypical.” Importantly, specific evidence-based medical interventions for CARDS (with the potential exception of corticosteroid use) are currently unavailable, limiting treatment efforts to mostly supportive ICU care.

In this article, we will discuss the underlying pulmonary pathophysiology and the clinical management of CARDS. In addition, we will outline current and potential future treatment approaches.

Outcomes of critically ill COVID-19 patients managed in a high-volume severe respiratory failure and ECMO centre in the United Kingdom

During the Coronavirus Disease 2019 (COVID-19) pandemic institutions have needed to develop pragmatic clinical pathways to balance the excess critical care demand and local resources. In this single-centre retrospective cohort study we describe the outcomes of COVID-19 patients admitted to Guy’s and St. Thomas’ NHS Foundation Trust (GSTT) critical care service. Patients were managed according to a local respiratory failure management pathway that was predicated on timely invasive ventilation when indicated and tailored ventilatory strategies according to pulmonary mechanics. Between 2 March and 25 May 2020 GSTT critical care service admitted 316 patients with confirmed COVID-19. Of the 201 patients admitted directly through the Emergency Department (ED) with a completed critical care outcome, 71.1% survived to critical care discharge. These favourable outcomes may serve to inform the wider debate on optimal organ support in COVID-19.

Pre-Hospital Management of Critically Ill Patients with SARS-CoV-2 Infection: A Retrospective Multicenter Study

INTRODUCTION

The COVID-19 outbreak had a major impact on healthcare systems worldwide. Our study aims to describe the characteristics and therapeutic emergency mobile service (EMS) management of patients with vital distress due to COVID-19, their in-hospital care pathway and their in-hospital outcome.

METHODS

This retrospective and multicentric study was conducted in the six main centers of the French Greater East region, an area heavily impacted by the pandemic. All patients requiring EMS dispatch and who were admitted straight to the intensive care unit (ICU) were included. Clinical data from their pre-hospital and hospital management were retrieved.

RESULTS

We included a total of 103 patients (78.6% male, median age 68). In the initial stage, patients were in a critical condition (median oxygen saturation was 72% (60-80%)). In the field, 77.7% (CI 95%: 71.8-88.3%) were intubated. Almost half of our population (45.6%, CI 95%: 37.1-56.9%) had clinical Phenotype 1 (silent hypoxemia), while the remaining half presented Phenotype 2 (acute respiratory failure). In the ICU, a great number had ARDS (77.7%, CI 95% 71.8-88.3% with a PaO2/FiO2 < 200). In-hospital mortality was 33% (CI 95%: 24.6-43.3%). The two phenotypes showed clinical and radiological differences (respiratory rate, OR = 0.98, p = 0.02; CT scan lesion extension >50%, OR = 0.76, p < 0.03). However, no difference was found in terms of overall in-hospital mortality (OR = 1.07, p = 0.74).

CONCLUSION

The clinical phenotypes appear to be very distinguishable in the pre-hospital field, yet no difference was found in terms of mortality. This leads us to recommend an identical management in the initial phase, despite the two distinct presentations.