Physiological effects of wearing N95 respirator on medical staff during prolong work hours in Covid-19 departments (preprint)

Objective: Since the emergence of coronavirus disease, health care professionals in high-risk environments are mandated to wear N95 respirators for prolonged periods. The effect of this prolonged use on cardio-respiratory variables and gas-exchange is poorly defined. The objective of the current study was to determine gas exchange abnormalities and physiological changes among healthcare workers during a 4-hour emergency department (ED) shift while wearing the N95 respirator. Methods: This was a single-center prospective observational study that consisted of medical staff working at the Sheba Medical Center ED. Physiological effects and gas exchange variables were obtained under normal breathing conditions and after 4-hour shifts while continuously wearing an N95 respirator. Comparisons of paired measurements were performed using a non-parametric Wilcoxon matched-pairs signed-rank test. Results: Forty-one subjects were included in the study. Prolonged N95 respirator use was associated with a significant decline in plasma pH [7.35mmHg vs. 7.34mmHg, P=0.02], PvO2 [23.2 mmHg vs. 18.6 mmHg, P<0.001] and a concurrent increase in EtCO2 [32.5mmHg vs. 38.5mmHg, p<0.0001]. PvCO2 and bicarbonate levels did not differ. No significant change was observed for heart rate or oxygen saturation. Conclusion: Using an N95 respirator for prolonged periods by healthcare professionals may provoke changes in gas exchange. The clinical significance of these changes in terms of symptoms or longer-term health status is unknown and remains to be determined. Key Words: N95 Respirator, Physiological effects, SARS CoV 2.

Newly discovered Pituitary Adenoma in the Emergency Center during the COVID-19 Pandemic in Serbia: Treatment and Early Postoperative Outcome (preprint)

Introduction:Pituitary tumors represent 10-15% of all intracranial tumors. Clinical manifestations depend on the size of the tumor such as microadenoma, macroadenoma or giant adenoma, and type of the tumor (secreting or non-secreting). Surgical treatment of pituitary adenoma can be managed via transcranial or transsphenoidal approach. Depending on the approach, there is a possibillity of postoperative complications such as meningitis, pneumocephalus, liquorrhea, transient diabetes insipidus and ect. Aim:The aim of this study was to establish the frequency of newly discovered pituitary tumors in the Emergency Center, University Clinical Center Of Serbia, during the COVID-19 pandemic in Serbia, and early postoperative complications in patients treated with an endoscopic and microscope transsphenoidal approach. Material and methods: During the time period during the pandemic, the study contains 119 patients, from January 1, 2020 to March 1, 2023, of which 64 are male (53.8%) and 55 are female (46.2%), age range is 14 to 85 years with a mean of 52.10. As for statistical analysis, assessment of frequency rate and relative numbers were used as methods of descriptive statistics. Results:Macroadenoma was present in 95 patients (79.83%), microadenoma in 22 patients (18.49%), and giant adenoma in 2 patients (1.69%). Transient DI developed postoperatively in 11 patients (9.24%). The average duration of hospitalization after surgery was 8 days. Conclusion: The duration of hospitalization depends on numerous factors where the COVID-19 pandemic can serve as an example for future similar crisis situations so that better organization and preoperative preparation of patients can be implemented.

Molecular pathology of acute respiratory distress syndrome, mechanical ventilation and abnormal coagulation in severe COVID-19 (preprint)

Systemic inflammation in critically ill patients can lead to serious consequences such as acute respiratory distress syndrome (ARDS), a condition characterized by the presence of lung inflammation, edema, and impaired gas exchange, associated with poor survival. Understanding molecular pathobiology is essential to improve critical care of these patients. To this end, we use multimodal profiles of SARS-CoV-2 infected hospitalized participants to the Biobanque Quebecoise de la COVID-19 (BQC-19) to characterize endophenotypes associated with different degrees of disease severity. Proteomic, metabolomic, and genomic characterization supported a role for neutrophil-associated procoagulant activity in severe COVID-19 ARDS that is inversely correlated with sphinghosine-1 phosphate plasma levels. Fibroblast Growth Factor Receptor (FGFR) and SH2-containing transforming protein 4 (SHC4) signaling were identified as molecular features associated with endophenotype 6 (EP6). Mechanical ventilation in EP6 was associated with alterations in lipoprotein metabolism. These findings help define the molecular mechanisms related to specific severe outcomes, that can be used to identify early unfavorable clinical trajectories and treatable traits to improve the survival of critically ill patients.

Point-of-Care Testing, Spatial Care Paths, and Enhanced Standards of Care – Preparing Island Communities for Global Warming and Rising Oceans (preprint)

Abstract: Our goal is to create point-of-care (POC) strategies that accelerate decision making, increase efficiency, improve outcomes, and enhance standards of care in island communities faced with global warming, rising oceans, population migration, and intensifying weather disasters. We assessed needs in the Bantayan Archipelago and mainland Cebu Province, Visayas Islands, Philippines, to map POC diagnostics, rescue times, and spatial care paths. Significant deficiencies were lack of cardiac troponin testing for rapid diagnosis of acute myocardial infarction, absence of blood gas and pH testing for support of critically ill patients, and geographic gaps prolonging patient transfers and delaying treatment. Strengths comprised primary care that can be facilitated by POC testing, logical inter-island transfers for which decision making and triage could be accelerated with onboard diagnostic testing, and healthcare small-world networks amenable to POC advances, such as pre-hospital testing, that avoid overloading emergency rooms. Healthcare resources must be distributed to archipelago islands, not concentrated in large metropolitan areas inaccessible for emergency interventions. We conclude that a point-of-need focus will help improve public health, decrease disparities in mortality among rural islanders versus urban dwellers, and pave the way for heightened resilience in anticipation of the adverse impact of global warming on vulnerable coastal areas.

Endoscopic Endonasal Eustachian Tube Obliteration as a Treatment for Tension Pneumocephalus After Translabyrinthine Resection of Vestibular Schwannoma.

OBJECTIVE: Cerebrospinal fluid leak and pneumocephalus are rare but potentially devastating complications associated with translabyrinthine resection of cerebellopontine angle masses. Persistent pneumocephalus despite proximal eustachian tube (ET) obliteration is rare. We describe, to our knowledge, the first report of successful management of tension pneumocephalus by endoscopic endonasal ET obliteration using a novel V-loc (Covidien; Medtronic, Minneapolis, MN) suture technique. PATIENTS: A 63-year-old man presented with altered mental status 10 months after translabyrinthine excision of a left cerebellopontine angle vestibular schwannoma measuring 2.8 × 2.9 × 3.3 cm. Computed tomography demonstrated diffuse ventriculomegaly and new pneumocephalus along the right frontal lobe, lateral ventricles, and third ventricle, and air within the left translabyrinthine resection cavity. INTERVENTION: The patient underwent left-sided endoscopic endonasal ET obliteration using 2-0, 9-inch V-loc suture. MAIN OUTCOME MEASURE: Postoperatively, the patient's mental status improved with a decrease in size of the lateral and third ventricles on computed tomography. CONCLUSION: Endoscopic endonasal ET obliteration, a technique previously applied to recalcitrant cerebrospinal fluid leaks, is a safe and reasonable alternative to reentering the original surgical site for patients with pneumocephalus after lateral skull base surgery. Utilizing a V-loc suture for this technique instead of a traditional suture may improve procedural ease and speed.

Dynamic Clinical Features During the Para-Exacerbation Period of Critical COVID-19 Patients (preprint)

Background COVID-19 has been currently spread all over the world with high mortality reported in severe COVID-19 patients. Many severe COVID-19 patients exacerbated from mild illness several days after hospital admissions. Pathophysiological evolution within this para-exacerbation period remain unclear.Methods Twenty-two confirmed COVID-19 patients who underwent at least one exacerbation were included. Epidemiological, clinical, laboratory, and radiological data were extracted from electronic medical records and compared between the records of hospital admission day and the exacerbation day. Dynamic profiles of critical parameters were explored during the para-exacerbation period.Results Most of the patients were elder (67, IQR63-79), male (81.8%), coexisted with comorbidities (72.7%), multi-segments radiologically involved and exacerbated from mild to severe illness with anoxia at a median interval of 4 days (IQR, 2-7) from hospital admissions. On exacerbations, various clinical parameters were worsened, including respiratory rate, PaO2/FiO2 rate (PFR), alveolar-arterial PO2 difference (A-aDO2), hematological cellularities, biochemical parameters and radiological abnormalities. Dynamic profiles showed that neutrophil/lymphocyte ratio (NLR), and serum level of lactic acid, lactate dehydrogenase and coagulation parameters started to increase even at four days before the exacerbation. Conclusions Anoxia due to impaired gas exchange progress pathophysiologically characterized the exacerbation of COVID-19 patients. Continuously monitoring crucial clinical parameters, such as NLR, serum albumin, LDH, lactic acid, and CT involvement scale will be helpful to improve the recognition of the disease progression in patients with COVID-19 at early stage.Trial registration This retrospective study has been registered in Chinese Clinical Trial Registry (ChiCTR2000030580, www.chictr.org.cn)

Risk and impact of using mask on COPD patients with acute exacerbation during the COVID-19 outbreak: a retrospective study (preprint)

Background：Chronic Obstructive Pulmonary Disease（COPD) is an inflammatory airway disease characterized by the presence of expiratory flow limitation. Exacerbations of COPD are common acute events. During epidemic of COVID-19, concerns have been raised with regard to mask- using because of increasing respiratory resistance. In this study, we aimed to evaluate the relationship between the vital signs , inflammation index, hypercapnia, hypoxia and mask-using in AECOPD patients.Methods：This retrospective study was performed at a tertiary hospital, and enrolled 23 patients with AECOPD who were hospitalized three or more times in the respiratory department. Patients in Group C were hospitalized and used masks during the epidemic period of COVID-19. Patient’s data of the previous two hospitalizations from the medical record system divided into group A and group B according to the time sequence. Vital signs, inflammation index, artery blood gas from medical record system and questionnaires of three hospitalizations in the same patient were collected to perform paired test.Results: Surgical mask using increased the levels of PaCO2 (8.98mm Hg; p = 0.004), HCO3-act (4.1mmol/L; p =0.006), BE (3.01mmol/L; p =0.019) and systolic blood pressure (11.39mm Hg; p = 0.01) in patients with AECOPD compared to last hospitalization. Surgical mask using for 30 to 120 minutes is associated with hypercapnia. There were no significant differences observed between group B and group A without using mask in vital signs, inflammation index, and artery blood gas.Conclusions: In this study, we found that systolic blood pressures and PaCO2, HCO3-act, BE were significantly elevated in AECOPD patients using masks compared to the other groups without masks. In addition，the changes in PaCO2,HCO3-act,BE is closely related to serum chloride concentration. Therefore, it is need to increase awareness and understanding of the use of masks in patients with chronic cardiopulmonary diseases.

COVID-19 Critical Illness Pathophysiology Driven by Diffuse Pulmonary Thrombi and Pulmonary Endothelial Dysfunction Responsive to Thrombolysis (preprint)

Patients with severe COVID-19 disease have been characterized as having the acute respiratory distress syndrome (ARDS). Critically ill COVID-19 patients have relatively well-preserved lung mechanics despite severe gas exchange abnormalities, a feature not consistent with classical ARDS but more consistent with pulmonary vascular disease. Patients with severe COVID-19 also demonstrate markedly abnormal coagulation, with elevated D-dimers and higher rates of venous thromboembolism. We present five cases of patients with severe COVID-19 pneumonia with severe respiratory failure and shock, with evidence of markedly elevated dead-space ventilation who received tPA. All showed post treatment immediate improvements in gas exchange and/or hemodynamics. We suspect that severe COVID-19 pneumonia causes respiratory failure via pulmonary microthrombi and endothelial dysfunction. Treatment for COVID-19 pneumonia may warrant anticoagulation for milder cases and thrombolysis for more severe disease.

Advanced Respiratory Monitoring in COVID-19 Patients: Use Less PEEP! (preprint)

With the emergence of COVID-19 we are confronted with a new clinical picture of acute respiratory distress syndrome in the intensive care unit. In the majority of patients, the respiratory mechanics are very different from the “normal” ARDS patient. We measured transpulmonary pressure and dead space ventilation to assess the effects of high and low PEEP levels on lung compliance and ventilation-perfusion mismatching. Advanced respiratory mechanics were assessed in 14 patients. Compared to ARDS patients, lung compliance was relatively high (61 ± 5 mL/cmH2O). COVID-19 patients had high dead space ventilation and gas exchange impairment (Bohr 52 ± 3%; Enghoff modification 67 ± 2%; ventilatory ratio 2.24 ± 0.23). we show that higher PEEP levels decrease lung compliance and in most cases increase dead space ventilation, indicating that high PEEP levels probably cause hyperinflation in patients with COVID-19. We suggest using prone position for an extended period of time, and apply lower PEEP levels as much as possible.