Prolonged higher dose methylprednisolone versus conventional dexamethasone in COVID-19 pneumonia: a randomised controlled trial (MEDEAS).

BACKGROUND: Dysregulated systemic inflammation is the primary driver of mortality in severe coronavirus disease 2019 (COVID-19) pneumonia. Current guidelines favour a 7-10-day course of any glucocorticoid equivalent to dexamethasone 6 mg daily. A comparative randomised controlled trial (RCT) with a higher dose and a longer duration of intervention was lacking. METHODS: We conducted a multicentre, open-label RCT to investigate methylprednisolone 80 mg as a continuous daily infusion for 8 days followed by slow tapering versus dexamethasone 6 mg once daily for up to 10 days in adult patients with COVID-19 pneumonia requiring oxygen or noninvasive respiratory support. The primary outcome was reduction in 28-day mortality. Secondary outcomes were mechanical ventilation-free days at 28 days, need for intensive care unit (ICU) referral, length of hospitalisation, need for tracheostomy, and changes in C-reactive protein (CRP) levels, arterial oxygen tension/inspiratory oxygen fraction (P aO2 /F IO2 ) ratio and World Health Organization Clinical Progression Scale at days 3, 7 and 14. RESULTS: 677 randomised patients were included. Findings are reported as methylprednisolone (n=337) versus dexamethasone (n=340). By day 28, there were no significant differences in mortality (35 (10.4%) versus 41 (12.1%); p=0.49) nor in median mechanical ventilation-free days (median (interquartile range (IQR)) 23 (14) versus 24 (16) days; p=0.49). ICU referral was necessary in 41 (12.2%) versus 45 (13.2%) (p=0.68) and tracheostomy in 8 (2.4%) versus 9 (2.6%) (p=0.82). Survivors in the methylprednisolone group required a longer median (IQR) hospitalisation (15 (11) versus 14 (11) days; p=0.005) and experienced an improvement in CRP levels, but not in P aO2 /F IO2 ratio, at days 7 and 14. There were no differences in disease progression at the prespecified time-points. CONCLUSION: Prolonged, higher dose methylprednisolone did not reduce mortality at 28 days compared with conventional dexamethasone in COVID-19 pneumonia.

Serum biomarkers of remodeling in severe asthma with fixed airway obstruction and the potential role of KL-6.

Over 3% of asthmatic patients are affected by a particularly severe form of the disease ("severe asthma", SA) which is often refractory to standard treatment. Airway remodeling (AR), which can be considered a critical characteristic of approximately half of all patients with SA and currently thought to be the main mechanism triggering fixed airway obstruction (FAO), seems to be a key factor affecting a patient's outcome. Despite the collective efforts of internationally renowned experts, to date only a few biomarkers indicative of AR and no recognizable biomarkers of lung parenchymal remodeling have been identified. This work examines the pathogenesis of airway and lung parenchymal remodeling and the serum biomarkers that may be able to identify the severe asthmatic patients who may develop FAO. The study also aims to examine if Krebs von den Lungen-6 (KL-6) could be considered a diagnostic biomarker of lung structural damage in SA.

Radiomics of spinal muscles: toward a radiological biomarker for allograft rejection in lung transplant.

PURPOSE: To assess the role of muscle composition and radiomics in predicting allograft rejection in lung transplant. MATERIAL AND METHODS: The last available HRCT before surgery of lung transplant candidates referring to our tertiary center from January 2010 to February 2020 was retrospectively examined. Only scans with B30 kernel reconstructions and 1 mm slice thickness were included. One radiologist segmented the spinal muscles of each patient at the level of the 11th dorsal vertebra by an open-source software. The same software was used to extract Hu values and 72 radiomic features of first and second order. Factor analysis was applied to select highly correlating features and then their prognostic value for allograft rejection was investigated by logistic regression analysis (level of significance p < 0.05). In case of significant results, the diagnostic value of the model was computed by ROC curves. RESULTS: Overall 200 patients had a HRCT prior to the transplant but only 97 matched the inclusion criteria (29 women; mean age 50.4 ± 13 years old). Twenty-one patients showed allograft rejection. The following features were selected by the factor analysis: cluster prominence, Imc2, gray level non-uniformity normalized, median, kurtosis, gray level non-uniformity, and inverse variance. The radiomic-based model including also Hu demonstrated that only the feature Imc2 acts as a predictor of allograft rejection (p = 0.021). The model showed 76.6% accuracy and the Imc2 value of 0.19 demonstrated 81% sensitivity and 64.5% specificity in predicting lung transplant rejection. CONCLUSION: The radiomic feature Imc2 demonstrated to be a predictor of allograft rejection in lung transplant.

Relative Humidity and Its Impact on the Immune System and Infections.

Relative humidity (RH) represents an underestimated outdoor and indoor environmental parameter. Conditions below and above the optimal range could facilitate infectious transmission as well as the exacerbation of respiratory diseases. The aim of this review is to outline the consequences for health of suboptimal RH in the environment and how to limit this negative impact. RH primarily affects the rheological properties of the mucus, modifying its osmolarity and thus the mucociliary clearance. The integrity of the physical barrier, maintained by mucus and tight junctions, is critical for protection from pathogens or irritants. Moreover, the control of RH seems to be a strategy to prevent and control the spread of viruses and bacteria. However, the imbalance of RH in the outdoor and indoor environments is frequently associated with the presence of other irritants, allergens, and pathogens, and therefore the burden of a single risk factor is not clearly defined in different situations. Nonetheless, RHmay have a synergistic negative effect with these risk factors, and its normalization, if possible, may have a positive impact on a healthier environment.

The "Asthma-Polycystic Ovary Overlap Syndrome" and the Therapeutic Role of Myo-Inositol.

Asthma is a heterogeneous inflammatory disease characterized by abnormalities in immune response. Due to the inherent complexity of the disease and the presence of comorbidities, asthma control is often difficult to obtain. In asthmatic patients, an increased prevalence of irregular menstrual cycles, infertility, obesity, and insulin resistance has been reported. Given that these conditions are also common in patients with polycystic ovary syndrome (PCOS), we propose the definition of "asthma-PCOS overlap syndrome" to indicate a medical condition which shares characteristics of both diseases. The aim of this review is to analyze the links between asthma and PCOS and evaluate the therapeutic role of myo-inositol, a natural compound currently utilized in patients with PCOS, in the management of asthma patients.

The pathogenesis, epidemiology and biomarkers of susceptibility of pulmonary fibrosis in COVID-19 survivors.

Pulmonary fibrosis (PF), a pathological outcome of chronic and acute interstitial lung diseases associated to compromised wound healing, is a key component of the "post-acute COVID-19 syndrome" that may severely complicate patients' clinical course. Although inconclusive, available data suggest that more than a third of hospitalized COVID-19 patients develop lung fibrotic abnormalities after their discharge from hospital. The pathogenesis of PF in patients recovering from a severe acute case of COVID-19 is complex, and several hypotheses have been formulated to explain its development. An analysis of the data that is presently available suggests that biomarkers of susceptibility could help to identify subjects with increased probability of developing PF and may represent a means to personalize the management of COVID-19's long-term effects. Our review highlights the importance of both patient-related and disease-related contributing risk factors for PF in COVID-19 survivors and makes it definitely clear the possible use of acute phase and follow-up biomarkers for identifying the patients at greatest risk of developing this disease.

Cardiopulmonary exercise testing in patients with moderate-severe obesity: a clinical evaluation tool for OSA?

PURPOSE: Obstructive sleep apnea (OSA) is a widespread comorbidity of obesity. Nasal continuous positive airway pressure (CPAP) has been demonstrated very effective in treating patients with OSA. The aims of this study were to investigate whether or not cardiopulmonary exercise testing (CPET) can characterize patients with OSA and to evaluate the effect of nasal CPAP therapy. METHODS: An observational study was conducted on patients with moderate to severe obesity and suspected OSA. All patients underwent cardiorespiratory sleep study, spirometry, and functional evaluation with ECG-monitored, incremental, maximal CPET. RESULTS: Of the 147 patients, 94 presented with an apnea-hypopnea index (AHI) ≥ 15 events/h and were thus considered to have OSA (52 receiving nasal CPAP treatment; 42 untreated) while 53 formed a control group (AHI < 15 events/h). Patients with untreated OSA showed significantly lower oxygen uptake (VO2), heart rate, minute ventilation (VE), and end tidal carbon dioxide (PETCO2) at peak exercise compared to controls. Patients receiving nasal CPAP showed higher VE and VO2 at peak exercise compared to untreated patients. A difference in PETCO2 between the maximum value reached during test and peak exercise (ΔPETCO2 max-peak) of 1.71 mmHg was identified as a predictor of OSA. CONCLUSION: Patients with moderate to severe obesity and untreated OSA presented a distinctive CPET-pattern characterized by lower aerobic and exercise capacity, higher PETCO2 at peak exercise associated with a lower ventilatory response. Nasal CPAP treatment was shown to positively affect these cardiorespiratory adaptations during exercise. ΔPETCO2 max-peak may be used to suggest OSA in patients with obesity.

Clinical trial on the effects of oral magnesium supplementation in stable-phase COPD patients.

BACKGROUND AND AIMS: COPD is a common chronic condition in older age that impacts on daily activities and quality of life. Previous studies suggest that magnesium deficit in COPD patients affects bronco-obstruction, inflammation, and physical performance. We investigated whether oral magnesium supplementation in stable-phase COPD patients improves lung function, physical performance, and quality of life. METHODS: We conducted a double-blind randomized-controlled clinical study with 49 participants divided into two groups: one given 300 mg/day of magnesium citrate (n = 25) and the other one sachet/day of a placebo (n = 24). The following parameters were assessed at baseline and after 3 and 6 months: lung function (spirometry), physical performance (handgrip strength, lower limb strength, six-minute walk test), inflammation (e.g., C-reactive protein, CRP), disease-related symptoms, and quality of life (St George's Respiratory Questionnaire, EuroQoL-5D, the Modified British Medical Research Council Questionnaire). RESULTS: Linear mixed models revealed significantly lower CRP values in the intervention group than in the placebo group at the 6 month follow-up (ß = - 3.2, 95% CI - 6.0, - 0.4, p = 0.03). Moreover, the maximum work for flexion tended to increase in both groups between the 3 and the 6 month assessments, especially in the placebo group. No significant differences within and between groups over the study period were observed for the other parameters tested. CONCLUSIONS: Although the established minimum sample size was not reached, our results suggests that oral magnesium supplementation may have a potential anti-inflammatory role. On the other hand, it does not seem to substantially influence lung function, physical performance, and quality of life in COPD patients. TRIAL REGISTRATION: The study is registered in clinicaltrial.gov (Trial Registration: NCT02680769, 13 June 2016, retrospectively registered).

QOLEC2: a randomized controlled trial on nutritional and respiratory counseling after esophagectomy for cancer.

BACKGROUND: Esophagectomy for cancer strongly impairs quality of life. The aim of this trial was to evaluate the effect of the nutritional and respiratory counseling on postoperative quality of life. METHODS: At hospital discharge, patients were randomized into four groups receiving respectively: nutritional and respiratory counseling, nutritional counseling alone, respiratory counseling alone, or standard care. The main endpoint was the impairment in quality of life in the first month after surgery. Linear mixed effect models were estimated to assess mean score differences (MDs) in quality of life scores. RESULTS: Patients receiving nutritional counseling reported less appetite loss (MD - 17.7, 95% CI - 32.2 to -3.3) than those not receiving nutritional counseling at 1 month after surgery. Dyspnea was similar between patients receiving vs. those not receiving respiratory counseling (MD - 3.1, 95% CI - 10.8 to 4.6). Global quality of life was clinically similar between patients receiving vs. those not receiving nutritional counseling over time (MD 0.9, 95% CI - 5.5 to 7.3), as well as in patients receiving vs. those not receiving respiratory counseling over time (MD 0.7, 95% CI - 5.9 to 7.2). CONCLUSIONS: Intensive postoperative care does not affect global quality of life even if nutritional counseling reduced appetite loss.

High-flow nasal cannula oxygen therapy to treat patients with hypoxemic acute respiratory failure consequent to SARS-CoV-2 infection.

This observational study aims to assess the outcome and safety of O2-therapy by high-flow nasal cannula (HFNC) in 28 consecutive patients with severe hypoxemic acute respiratory failure (hARF) consequent to SARS-CoV-2 infection, unresponsive to conventional O2-therapy. Nineteen patients had a positive response. Nine patients required escalation of treatment to non-invasive ventilation (five subsequently intubated). None of the staff had a positive swab testing during the study period and the following 14 days. Severity of hypoxemia and C reactive protein level were correlated with HFNC failure. These data suggest HFNC to be a safe treatment for less severe patients with SARS-CoV-2 hARF and efficacy will need to be assessed as part of a clinical trial.

Feasibility and clinical impact of out-of-ICU noninvasive respiratory support in patients with COVID-19-related pneumonia.

INTRODUCTION: The severe acute respiratory syndrome-coronavirus 2 outbreak spread rapidly in Italy and the lack of intensive care unit (ICU) beds soon became evident, forcing the application of noninvasive respiratory support (NRS) outside the ICU, raising concerns over staff contamination. We aimed to analyse the safety of the hospital staff and the feasibility and outcomes of NRS applied to patients outside the ICU. METHODS: In this observational study, data from 670 consecutive patients with confirmed coronavirus disease 2019 referred to pulmonology units in nine hospitals between March 1 and May 10, 2020 were analysed. Data collected included medication, mode and usage of NRS (i.e. high-flow nasal cannula (HFNC), continuous positive airway pressure (CPAP), noninvasive ventilation (NIV)), length of stay in hospital, endotracheal intubation (ETI) and deaths. RESULTS: 42 (11.1%) healthcare workers tested positive for infection, but only three of them required hospitalisation. Data are reported for all patients (69.3% male), whose mean±sd age was 68±13 years. The arterial oxygen tension/inspiratory oxygen fraction ratio at baseline was 152±79, and the majority (49.3%) of patients were treated with CPAP. The overall unadjusted 30-day mortality rate was 26.9%, with 16%, 30% and 30% for HFNC, CPAP and NIV, respectively, while the total ETI rate was 27%, with 29%, 25% and 28%, respectively; the relative probability of death was not related to the NRS used after adjustment for confounders. ETI and length of stay were not different among the groups. Mortality rate increased with age and comorbidity class progression. CONCLUSIONS: The application of NRS outside the ICU is feasible and associated with favourable outcomes. Nonetheless, it was associated with a risk of staff contamination.

Dyspnea, effort and muscle pain during exercise in lung transplant recipients: an analysis of their association with cardiopulmonary function parameters using machine learning.

BACKGROUND: Despite improvement in lung function, most lung transplant (LTx) recipients show an unexpectedly reduced exercise capacity that could be explained by persisting peripheral muscle dysfunction of multifactorial origin. We analyzed the course of symptoms, including dyspnea, muscle effort and muscle pain and its relation with cardiac and pulmonary function parameters during an incremental exercise testing. METHODS: Twenty-four bilateral LTx recipients were evaluated in an observational cross-sectional study. Recruited patients underwent incremental cardio-pulmonary exercise testing (CPET). Arterial blood gases at rest and peak exercise were measured. Dyspnea, muscle effort and muscle pain were scored according to the Borg modified scale. Potential associations between the severity of symptoms and exercise testing parameters were analyzed using a Forest-Tree Machine Learning approach, which accomplishes for a ratio between number of observations and number of screened variables less than unit. RESULTS: Dyspnea score was significantly associated with maximum power output (WR, watts), and minute ventilation (VE, L/min) at peak exercise. In a controlled subgroup analysis, dyspnea score was a limiting symptom only in LTx recipients who reached the higher levels of WR (≥ 101 watts) and VE (≥ 53 L/min). Muscle effort score was significantly associated with breathing reserve as percent of maximal voluntary ventilation (BR%MVV). The lower the BR%MVV at peak exercise (< 32) the higher the muscle effort perception. Muscle pain score was significantly associated with VO2 peak, arterial [HCO3-] at rest, and VE/VCO2 slope. In a subgroup analysis, muscle pain was the limiting symptom in LTx recipients with a lower VO2 peak (< 15 mL/Kg/min) and a higher VE/VCO2 slope (≥ 32). CONCLUSIONS: The majority of our LTx recipients reported peripheral limitation as the prevalent reason for exercise termination. Muscle pain at peak exercise was strictly associated with basal and exercise-induced metabolic altered pathways. The onset of dyspnea (breathing effort) was associated with the intensity of ventilatory response to meet metabolic demands for increasing WR. Our study suggests that only an accurate assessment of symptoms combined with cardio-pulmonary parameters allows a correct interpretation of exercise limitation and a tailored exercise prescription. The role and mechanisms of muscle pain during exercise in LTx recipients requires further investigations.

Exposure to dipeptidyl-peptidase-4 inhibitors and COVID-19 among people with type 2 diabetes: A case-control study.

Because other coronaviruses enter the cells by binding to dipeptidyl-peptidase-4 (DPP-4), it has been speculated that DPP-4 inhibitors (DPP-4is) may exert an activity against severe acute respiratory syndrome coronavirus 2. In the absence of clinical trial results, we analysed epidemiological data to support or discard such a hypothesis. We retrieved information on exposure to DPP-4is among patients with type 2 diabetes (T2D) hospitalized for COVID-19 at an outbreak hospital in Italy. As a reference, we retrieved information on exposure to DPP-4is among matched patients with T2D in the same region. Of 403 hospitalized COVID-19 patients, 85 had T2D. The rate of exposure to DPP-4is was similar between T2D patients with COVID-19 (10.6%) and 14 857 matched patients in the region (8.8%), or 793 matched patients in the local outpatient clinic (15.4%), 8284 matched patients hospitalized for other reasons (8.5%), and when comparing 71 patients hospitalized for COVID-19 pneumonia (11.3%) with 351 matched patients with pneumonia of another aetiology (10.3%). T2D patients with COVID-19 who were on DPP-4is had a similar disease outcome as those who were not. In summary, we found no evidence that DPP-4is might affect hospitalization for COVID-19.

Frequency and clinical correlates of antiphospholipid antibodies arising in patients with SARS-CoV-2 infection: findings from a multicentre study on 122 cases.

OBJECTIVES: COVID-19 features include disseminated intravascular coagulation and thrombotic microangiopathy indicating a hypercoagulable state. We aimed to investigate antiphospholipid antibodies (aPL) prevalence and clinical relationships in a large cohort of COVID-19 patients. METHODS: We analysed the prevalence and titres of serum aPL in 122 patients with COVID-19 and 157 with primary antiphospholipid syndrome (PAPS) and 91 with other autoimmune rheumatic diseases (oARD) for comparison. IgG/IgM anticardiolipin (aCL) and IgG/IgM anti-beta2glycoprotein I (ß2GPI) were assayed using homemade ELISA, IgA aCL and anti-ß2GPI by commercial ELISA kits and lupus anticoagulant (LAC) by multiple coagulation tests following updated international guidelines. RESULTS: Prevalence of IgG and IgM aCL and of IgG and IgM anti-ß2GPI across COVID-19 patients were 13.4%, 2.7%, 6.3% and 7.1%, being significantly lower than in PAPS (p<0.0001 for all). Frequency of IgG aCL and IgM anti-ß2GPI was comparable to oARD (13.4% vs. 13.2% and 7.1% vs. 11%, respectively), while IgG anti-ß2GPI and IgM aCL were lower (p<0.01). IgA aCL and IgA anti-ß2GPI were retrieved in 1.7% and 3.3% of COVID-19 patients, respectively. Positive LAC was observed in 22.2% COVID-19 vs. 54.1% of PAPS (p<0.0001) and 14.6% of oARD (p=0.21). Venous or arterial thromboses occurred in 18/46 (39.1%) COVID-19 patients and were not associated with positive aPL (p=0.09). CONCLUSIONS: Thrombosis is a frequent manifestation during COVID-19 infection. However, prevalence and titres of aPL antibodies or LAC were neither consistently increased nor associated with thrombosis when measured at a single timepoint, therefore not representing a suitable screening tool in the acute stage of disease.

Practical approach to respiratory emergencies in neurological diseases.

Many neurological diseases may cause acute respiratory failure (ARF) due to involvement of bulbar respiratory center, spinal cord, motoneurons, peripheral nerves, neuromuscular junction, or skeletal muscles. In this context, respiratory emergencies are often a challenge at home, in a neurology ward, or even in an intensive care unit, influencing morbidity and mortality. More commonly, patients develop primarily ventilatory impairment causing hypercapnia. Moreover, inadequate bulbar and expiratory muscle function may cause retained secretions, frequently complicated by pneumonia, atelectasis, and, ultimately, hypoxemic ARF. On the basis of the clinical onset, two main categories of ARF can be identified: (i) acute exacerbation of chronic respiratory failure, which is common in slowly progressive neurological diseases, such as movement disorders and most neuromuscular diseases, and (ii) sudden-onset respiratory failure which may develop in rapidly progressive neurological disorders including stroke, convulsive status epilepticus, traumatic brain injury, spinal cord injury, phrenic neuropathy, myasthenia gravis, and Guillain-Barré syndrome. A tailored assistance may include manual and mechanical cough assistance, noninvasive ventilation, endotracheal intubation, invasive mechanical ventilation, or tracheotomy. This review provides practical recommendations for prevention, recognition, management, and treatment of respiratory emergencies in neurological diseases, mostly in teenagers and adults, according to type and severity of baseline disease.

The mutual association between dyspnea and depressive symptoms in older adults: a 4-year prospective study.

Objectives: dyspnea in daily living (DDL), night-time dyspnea (NTD) and depression are common symptoms in older people. However, how changes in dyspnea may influence and be influenced by modifications in depressive symptoms, so far has not been fully evaluated. We aimed to estimate the extent to which both DDL and NTD could be mutually associated to depressive symptoms in older adults with chronic conditions.Methods: this prospective study includes 2322 community-dwelling individuals aged ≥65 years enrolled in the Progetto Veneto Anziani (Pro.V.A.). At baseline and after 4.4 years, we evaluated the following parameters: DDL, assessed by the Medical Research Council dyspnea scale (MRC); self-reported NTD, assessed by personal interview; depressive symptoms, assessed using the Geriatric Depression Scale (GDS). The strength of the association between dyspnea and depression over the follow-up was evaluated through logistic regression and estimated by odds ratios and 95%Confidence Intervals (95%CI). Corrected risk ratios (RR) were then approximated from odds ratios.Results: GDS changes over the follow-up positively correlated with MRC changes (ß = 0.938). Individuals with baseline DDL or NTD and those with incident/worsening DDL showed higher risk of developing or worsening depressive symptoms compared with their counterparts (RR = 3.36 [95%CI 2.11-5.06] for incident depression in people with worsening DDL). Incident or persistent depression increased more than twice the risk of developing DDL and NTD (for incident depression RR = 2.33 [95%CI 1.85-2.83] for DDL, and RR = 2.01 [95%CI 1.27-3.11] for NTD).Conclusions: older people may benefit from a comprehensive evaluation of respiratory and psychological symptoms, which seem to be related to each other in advanced age.

Spontaneous pneumomediastinum complicating severe acute asthma exacerbation in adult patients.

Objectives: The real incidence of pneumomediastinum (PNM) in adult patients with severe acute asthma exacerbation continues to be unknown. The current study aims to investigate the occurrence of PNM in an adult population of patients presenting a severe asthma attack and to evaluate the risk factors associated to its development. Methods: The 45 consecutive subjects who were admitted to our Division between January 1, 2015 and December 31, 2016 for severe acute asthma exacerbation underwent a diagnostic protocol including a standard chest X-ray and continuous monitoring of arterial oxygen saturation (SaO2) during the first 24 hours following admission. The patients showing persistence or deterioration of oxyhemoglobin desaturation were prescribed a chest Computed Tomographic (CT) scan. Results: Five out of the 45 patients (11.1%) with severe acute asthma exacerbation were diagnosed with PNM, in one case on the basis of an X-ray image and in four on the basis of a chest CT scan. Data analysis showed that the PNM patients were younger [21 (17-21) vs 49.5 (20-73) yrs; p < 0.001] and more likely to show sensitization to Alternaria (2/5 vs 0/40; p = 0.0101) with respect to their non-PNM counterparts. The duration of hospital stay was similar in the two groups [8 (4-12) vs 7 (3-15) days; p = 0.6939]. Conclusions: PNM is a common clinical entity in young adults with severe acute asthma exacerbation, particularly in those with unsatisfactory response to initial medical therapy. Although generally benign, patients with suspected PNM should be closely monitored because of the risk of developing severe hypoxemia.

Optoelectronic Plethysmography in Clinical Practice and Research: A Review.

BACKGROUND: Optoelectronic plethysmography (OEP) is a non-invasive motion capture method to measure chest wall movements and estimate lung volumes. OBJECTIVES: To provide an overview of the clinical findings and research applications of OEP in the assessment of breathing mechanics across populations of healthy and diseased individuals. METHODS: A bibliographic research was performed with the terms "opto-electronic plethysmography," "optoelectronic plethysmography," and "optoelectronic plethysmograph" in 50 digital library and bibliographic search databases resulting in the selection of 170 studies. RESULTS: OEP has been extensively employed in studies looking at chest wall kinematics and volume changes in chest wall compartments in healthy subjects in relation to age, gender, weight, posture, and different physiological conditions. In infants, OEP has been demonstrated to be a tool to assess disease severity and the response to pharmacological interventions. In chronic obstructive pulmonary disease patients, OEP has been used to test if patients can dynamically hyperinflate or deflate their lungs during exercise. In neuromuscular patients, respiratory muscle strength and chest kinematics have been analyzed. A widespread application of OEP is in tailoring post-operative pulmonary rehabilitation as well as in monitoring volume increases and muscle contributions during exercise. CONCLUSIONS: OEP is an accurate and validated method of measuring lung volumes and chest wall movements. OEP is an appropriate alternative method to monitor and analyze respiratory patterns in children, adults, and patients with respiratory diseases. OEP may be used in the future to contribute to improvements in the therapeutic strategies for respiratory conditions.