Value of Peak Expiratory Flow Rate in Evaluating Cough Ability in Patients Undergoing Lung Surgery

Introduction. Postoperative ineffective cough is easy to occur after thoracic surgery, and it is also a risk factor for postoperative pulmonary complications (PPCs). Objectives. To explore the value of peak expiratory flow rate (PEF) in evaluating cough ability in patients undergoing lung surgery and evaluate the effectiveness of chest wall compression during the expiratory phase by PEF. Methods. From September 2020 to May 2021, the researchers collected the data of patients who underwent lung surgery. Eventually, 153 patients who met the criteria were included, 102 cases were included in the effective cough group and 51 cases were included in the ineffective cough group. The receiver working curve (ROC curve) was used to analyze whether PEF could evaluate cough ability. At the same time, the researchers collected the pulmonary function data of the first 30 patients of the ineffective cough group while compressing the chest wall during the expiratory phase to evaluate the effectiveness of chest wall compression. Results. The area under the curve (AUC) of postoperative PEF to evaluate the postoperative cough ability was 0.955 (95% CI: 0.927–0.983, P < 0.001 ). The values of PEF (127.17 ± 34.72 L/min vs. 100.70 ± 29.98 L/min, P < 0.001 , 95% CI: 18.34–34.59) and FEV1 (0.72 (0.68–0.97) L vs. 0.64 (0.56–0.82) L, P < 0.001 ) measured while compressing the chest wall were higher than those without compression. Conclusions. PEF can be used as a quantitative indicator of cough ability. Chest wall compression could improve cough ability for patients who have ineffective cough.

Dyslipidemia Associates with Respiratory Resistance Assessed by Forced Oscillation Technique in Asthmatic Children

Purpose: This study evaluated the correlation between dyslipidemia and pulmonary function parameters assessed by spirometry and force oscillation technique in asthmatic children.Methods: Asthmatic children (aged 5–18 years old) were measured for fasting serum lipid profiles, including low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C) and C-reactive protein (CRP). Pulmonary function tests were assessed by spirometry and forced oscillation technique (FOT). Results: One hundred forty-one asthmatic children were enrolled with the mean (sd) age of 11.82 (3.38) years. Eighty-eight children (62.4%) were males, 64 children (45.4%) had dyslipidemia, and 20 (14.2 %) children were obese. Of 64 children with dyslipidemia, high LDL-C was the most common dyslipidemia (65.6%), followed by TC (57.8%), non-HDL-C (53.1%), TG (35.9%), and low HDL-C (15.6%). There were no significant differences in spirometry parameters and FOT parameters between asthmatic children who had dyslipidemia and normal lipid levels. Asthmatic children who had high LDL-C had significantly higher expiratory phase respiratory resistance at 5 Hz (R5), whole breath R20 and expiratory phase R20 evaluated by FOT than those with normal LDL-C (p < 0.05). There were no significant differences in weight, height, obesity status, and CRP level between children with high and normal LDL-C. Conclusion: The prevalence of dyslipidemia in children with asthma is high. LDL-C is associated with more elevated respiratory resistance assessed by FOT in asthmatic children. Intervention lowering LDL-C may have a benefit on lung function in asthmatic children.

Comparative evaluation of expiratory airflow limitation between patients with COPD and BE using IOS

Impulse oscillometry (IOS) allows evaluation of the compartmentalized resistance and reactance of the respiratory system, distinguishing central and peripheral obstruction. The IOS measurements are getting attention in the diagnosis and differentiation of chronic respiratory diseases. However, no data are available in the literature to differentiate between COPD and BE using IOS parameters. We aimed to evaluate the feasibility of IOS in the diagnosis of bronchiectasis non-cystic fibrosis (BE) in comparison to COPD. Whole breath, inspiration, expiration, and inspiratory-expiratory difference (Δ) were evaluated based on the IOS parameters: total resistance (R5), central airway resistance (R20), peripheral airway resistance (R5-R20), reactance (X5), reactance area (AX), and resonance frequency (Fres). Fifty-nine subjects (21 Healthy, 19 BE, and 19 COPD) participated in this study. It was observed a significant difference in the comparison of healthy and pulmonary disease groups (BE and COPD) for total breathing (R5-R20, X5, AX, and Fres), inspiratory phase (R5 and R5-R5), and expiratory phase (R5-R20 and X5). The comparison between BE and COPD groups showed significant difference in the expiratory phase for resistance at 5 and 20 Hz and, ΔR5 and ΔR20. The IOS evidenced an increase of R5, R20 and R5-R20 in patients with BE and COPD when compared to healthy subjects. Expiratory measures of IOS revealed increased airway resistance in COPD compared to BE patients who had similar FEV1 measured by spirometry, however, further studies are needed to confirm these differences.

Correction of pathological periodic respiration with Mexidol in rats

В острых опытах на наркотизированных самцах беспородных белых крыс изучали возможность применения метаболической терапии мексидолом для коррекции периодического патологического дыхания, вызванного оксибутиратом. В интервале доз 40-200 мг/кг мексидол нормализовал дыхание, причем продолжительность нормализации зависела от его концентрации. При использовании мексидола в дозах 100-200 мг/кг длительность сохранения нормального ритмического дыхания составляла несколько часов. Проведенное исследование показало, что мексидол является эффективным средством коррекции периодического патологического дыхания с задержками в фазе спокойного выдоха, способный нормализовать дыхательный ритм на протяжении нескольких часов. A possibility of using the Mexidol metabolic therapy for correction of hydroxybutyrate-provoked periodic pathological respiration was evaluated in acute experiments on anesthetized white mongrel male rats. Mexidol at doses of 40-200 mg/kg dose-dependently normalized the respiratory rhythm. Mexidol at doses of 100-200 mg/kg maintained the normal, rhythmic respiration for several hours. Therefore, Mexidol is an effective drug for correction of the periodic pathological breathing with arrest in the quiet expiratory phase, which normalizes generation of the respiratory rhythm for several hours.

Dbx1 pre-Bötzinger complex interneurons comprise the core inspiratory oscillator for breathing in adult mice

ABSTRACTThe brainstem pre-Bötzinger complex (preBötC) generates inspiratory breathing rhythms, but which neurons comprise its rhythmogenic core? Dbx1-derived neurons may play the preeminent role in rhythm generation, an idea well founded at perinatal stages of development but not in adulthood. We expressed archaerhodopsin or channelrhodopsin in Dbx1 preBötC neurons in intact adult mice to interrogate their function. Prolonged photoinhibition slowed down or stopped breathing, whereas prolonged photostimulation sped up breathing. Brief inspiratory-phase photoinhibition evoked the next breath earlier than expected, whereas brief expiratory-phase photoinhibition delayed the subsequent breath. Conversely, brief inspiratory-phase photostimulation increased inspiratory duration and delayed the subsequent breath, whereas brief expiratory-phase photostimulation evoked the next breath earlier than expected. Because they govern the frequency and precise timing of breaths in awake adult mice with sensorimotor feedback intact, Dbx1 preBötC neurons constitute an essential core component of the inspiratory oscillator, knowledge directly relevant to human health and physiology.