Airway to Lung Volume Ratio on CT is Associated with Pulmonary Function Transition from Obstructive to Restrictive Pattern in Obesity

Background: Obesity is associated with excessive airway collapse and reduced lung volume; it is unknown whether it affects airway-lung interactions. We sought to compare the airway tree to lung volume ratio, assessed by CT, in obese individuals with and without ventilation disorders.Methods: Participants underwent inspiratory chest CT and pulmonary function. The percentage ratio of the whole airway tree to lung volume, automatically segmented via deep learning, was defined as CT airway volume percent (AWV%). Total airway count (TAC), airway wall area percent (WA%), and other CT indexes were also measured. Results: We evaluated 88 participants including adolescents(age: 14-18, n= 12) and adults (age: 19-25, n= 17; age: 26-35, n= 39; age> 35, n= 20). Obese adolescents had higher forced vital capacity (FVC) (P = 0.001) and lower AWV% (P = 0.008) than obese adults (age >35). Among obese adults, participants with restrictive disorders had larger AWV% (P < 0.001) and those with obstructive disorders showed smaller AWV% (P < 0.001) compared to participants with normal ventilation. AWV% was positively correlated with age and forced expiratory volume in 1 second (FEV1)/FVC and adversely related to FVC (P< 0.05 for all), and in multivariate models, AWV% independently predicted FEV1/FVC (R2 = 0.49, P < 0.001) and FVC (R2 = 0.60, P < 0.001).Conclusion: Transitions in lung function patterns between obese adolescents and adults are associated with airway to lung ratios. The obesity-induced disproportion between the airway tree and lung volume may adversely affect and complicate lung ventilation.

A randomised controlled trial on roles of prostaglandin E1 nebulization among patients undergoing one lung ventilation

Background Prostaglandin E1 (PGE1) has been reported to maintain adequate oxygenation among patients under 60% FiO2 one-lung ventilation (OLV). This research aimed to explore whether PGE1 is safe in pulmonary shunt and oxygenation under 40% FiO2 OLV and provide a reference concentration of PGE1. Methods Totally 90 esophageal cancer patients treated with thoracotomy were enrolled in this study, randomly divided into three groups (n = 30/group): Group A (60% FiO2 and 0.1 µg/kg PGE1), Group B (40% FiO2 and 0.1 µg/kg PGE1), and Group C (40% FiO2, 0.2 µg/kg PGE1). Primary outcomes were oxygenation and pulmonary shunt during OLV. Secondary outcomes included oxidative stress after OLV. Results During OLV, patients in Group C and B had lower levels of PaO2, SaO2, SpO2, MAP, and Qs/Qt than those in Group A (P < 0.05). At T2 (OLV 10 min), patients in Group C and B exhibited a lower level of PaO2/FiO2 than those in Group A, without any statistical difference at other time points. The IL-6 levels of patients in different groups were different at T8 (F = 3.431, P = 0.038), with IL-6 in Group C being lower than that in Group B and A. MDA levels among the three groups differed at T5 (F = 4.692, P = 0.012) and T7 (F = 5.906, P = 0.004), with the MDA level of Group C being lower than that of Group B and A at T5, and the MDA level of Group C and B being lower than that of Group A at T7. In terms of TNF-α level, patients in Group C had a lower level than those in Group B and A at T8 (F = 3.598, P = 0.033). Compared with patients who did not use PGE1, patients in Group C had comparable complications and lung infection scores. Conclusion The concentration of FiO2 could be reduced from 60 to 40% to maintain oxygenation. 40% FiO2 + 0.2 µg/kg PGE1 is recommended as a better combination on account of its effects on the inflammatory factors. Trial registration: Chictr.org.cn identifier: ChiCTR1800018288, 09/09/2018.

Prehospital Period in Patients with COVID-19: Cardiovascular Comorbidity and Pharmacotherapy During the First Epidemic Wave (Hospital Registry Data)

Aim. Based on the data from the register of patients with COVID-19 and community-acquired pneumonia (CAP), analyze the duration of the prehospital period, cardiovascular comorbidity and the quality of prehospital pharmacotherapy of concomitant cardiovascular diseases (CVD).Material and methods. Patients were included to the study which admitted to the FSBI "NMHC named after N.I. Pirogov" of the Ministry of Health of the Russian Federation with a suspected or confirmed diagnosis of COVID-19 and/or CAP. The data for prehospital therapy, information from medical histories and a patients’survey in the hospital or by telephone contact 1-2 weeks after discharge were study. The duration of the prehospital stage was determined from the date of the appearance of clinical symptoms of coronavirus infection to the date of hospitalization.Results. The average age of the patients (n=1130; 579 [51.2%] men and 551 [48.8%] women) was 57.5±12.8 years. The prehospital stage was 7 (5,0; 10,0) days and did not differ significantly in patients with the presence and absence of CVD, but was significantly less in the deceased than in the surviving patients, as well as in those who required artificial lung ventilation (ALV). 583 (51.6%) patients had at least one CVD. Cardiovascular comorbidity was registered in 222 (42.7%) patients with hypertension, 210 (95.5%) patients with coronary heart disease (CHD), 104 (91.2%) patients with atrial fibrillation (AF). The inclusion of non-cardiac chronic diseases in the analysis led to an increase in the total proportion of patients with concomitant diseases to 65.8%. Approximately a quarter of hypertensive patients did not receive antihypertensive therapy, a low proportion of patients receiving antiplatelet agents and statins for CHD was revealed – 53% and 31.8%, respectively, anticoagulants for AF – 50.9%.Conclusion. The period from the onset of symptoms to hospitalization was significantly shorter in the deceased than in the surviving patients, as well as in those who required ALV. The proportion of people with a history of at least one CVD was about half of the entire cohort of patients. In patients with CVD before COVID-19 disease, a low frequencies of prescribing antihypertensive drugs, statins, antiplatelet agents and anticoagulants (in patients with AF) were recorded at the prehospital stage.

LTB4 Promotes Acute Lung Injury via Upregulating the PLCε-1/TLR4/NF-κB Pathway in One-Lung Ventilation

Background. Mechanical ventilation (MV) can provoke acute lung injury (ALI) by increasing inflammation activation and disrupting the barrier in lung tissues even causing death. However, the inflammation-related molecules and pathways in MV-induced ALI remain largely unknown. Hence, the purposes of this study are to examine the role and mechanism of a novel inflammation-related molecule, leukotriene B4 (LTB4), in ALI. Methods. The functions of LTB4 in one-lung ventilation (OLV) model were detected by the loss-of-function experiments. H&E staining was used to examine the pathologic changes of lung tissues. Functionally, PLCε-1 knockdown and Toll-like receptor 4 (TLR4)/NF-κB pathway inhibitor were used to detect the regulatory effects of LTB4 on the phospholipase Cε (PLCε-1)/TLR4/nuclear factor-kappa B (NF-κB) pathway. The levels of genes and proteins were determined by RT-qPCR and western blotting assay. The levels of inflammation cytokines and chemokines were measured by ELISA. Results. Here, we found LTA4H, leukotriene B (4) receptor 1 (BLT1), LTB4, and PLCε-1 upregulated in OLV rats and associated with inflammatory activation and lung permeability changes of lung tissues. Inhibition of LTB4 alleviated the OLV-induced ALI by inhibiting inflammatory activation and lung permeability changes of lung tissues. For mechanism analyses, LTB4 promoted OLV-induced ALI by activating the PLCε-1/TLR4/NF-κB pathway. Conclusion. LTB4 induced ALI in OLV rats by activating the PLCε-1/TLR4/NF-κB pathway. Our findings might supply a new potential therapeutic for OLV-induced ALI.

Comparison of two-lung and one-lung ventilation in bilateral video-assisted thoracoscopic extended thymectomy in myasthenia gravis: a retrospective study

Background: Myasthenia gravis (MG) is an autoimmune disease, and early thymectomy is recommended. Since the introduction of video-assisted thoracoscopic surgery, the safety and effectiveness of carbon dioxide insufflation in the thoracic cavity (capnothorax) has been controversial. This study aimed to compare the safety and effectiveness of ventilation methods in bilateral video-assisted thoracoscopic extended thymectomy (BVET) with capnothorax.Methods: We retrospectively investigated the medical records of patients with MG who underwent BVET between August 2016 and January 2018. Patients were divided into two groups: group D (n = 26) for one-lung ventilation and group S (n = 28) for two-lung ventilation. We set nine anesthesia time points (T0–T8) and collected respiratory and hemodynamic variables, including arterial O2 index (PaO2/FiO2).Results: SpO2 at T1–T3 and T8 was significantly lower in group D than in group S. The FiO2 in group S was lower than that in group D at all time points. The number of PaO2/FiO2 ≤ 300 and PaO2/FiO2 ≤ 200 events was significantly higher in group D than in group S. Hemodynamic variables were not significantly different between the two groups at any time point. The duration of surgery and anesthesia was shorter in group S than in group D. Conclusions: This retrospective study suggests that anesthesia using two-lung ventilation during BVET with capnothorax is a safe and effective method to improve lung oxygenation and reduce anesthesia time.