Respiratory Function Research Articles (Page 1)

General anesthesia induces both unconsciousness and respiratory depression, but whether these effects share a common neural substrate remains unclear. The parafacial zone, a γ-aminobutyric acid-mediated (GABAergic) sleep-promoting region, has been proposed to modulate respiration. This study investigates whether parafacial zone GABAergic neurons function as a common neural node coordinating anesthetic-induced unconsciousness and respiratory suppression. A total of 95 male mice (10 to 12 weeks old) were used. Chemogenetic and optogenetic methods targeted parafacial zone GABAergic neurons to assess anesthetic efficacy and respiratory changes. Immunostaining evaluated neuronal activation, and awake-state stimulation tested for anesthesia-like effects. Chemogenetic activation of parafacial zone GABAergic neurons enhanced anesthetic sensitivity, shifting the sevoflurane dose-response curve leftward (50% effective dose, 0.662%; 95% confidence interval, 0.624 to 0.699% vs . 1.569%; 95% confidence interval, 1.502 to 1.637%) and lowering the concentration required for loss of righting reflex (0.735 ± 0.027% vs . 1.601 ± 0.048%; P < 0.0001; n = 10). Induction was faster (48 ± 4 s vs . 112 ± 3 s; P < 0.0001; n = 8), and emergence was delayed (435 ± 12 s vs . 89 ± 12 s; P < 0.0001; n = 8). Electroencephalogram showed increased delta and decreased theta power. Respiratory rate declined significantly (183 ± 24 breaths/min vs . 471 ± 3 breaths/min; P < 0.0001; n = 8). During anesthesia, brief optogenetic activation of parafacial zone GABAergic neurons immediately elevated the burst suppression ratio (69.5 ± 5.1% vs . 32.5 ± 7.7%; P < 0.0001; n = 9) and reduced the respiratory rate (38 ± 13 breaths/min vs . 120 ± 21 breaths/min; P = 0.0016; n = 7), indicating concurrent modulation of cortical and respiratory function. Chemogenetic inhibition weakened anesthetic potency. Increased c-Fos expression in parafacial zone GABAergic neurons during sevoflurane anesthesia confirmed their recruitment. In awake mice, optogenetic activation alone induced a low-arousal state with several features of anesthesia, including hypoactivity, analgesia, respiratory depression, and cortical suppression without abolishing righting reflex. The GABAergic parafacial zone is a shared critical node regulating both respiration and consciousness during sevoflurane anesthesia. Its activation suppresses both, helping explain anesthesia-related respiratory depression.

To investigate the effectiveness of a virtual reality-based rehabilitation (VRBR) program in individuals with Adolescent Idiopathic Scoliosis (AIS) who have undergone posterior fusion surgery (PSF). A total of 28 AIS patients who had undergone PSF surgery were included in the study. Participants were randomly assigned to either the VRBR group (n = 14) or the Control group (n = 14). The VRBR group received a rehabilitation program using the Kinect Xbox 360 for 30min, twice a week, over a period of 6 weeks. The Control group was prescribed a comparable set of exercises to be performed as a home-based program over the same duration. Spinal mobility was assessed using the Modified Schober Test, and respiratory muscle strength was measured with a portable Micro RPM device. Physical activity levels were monitored using a pedometer, kinesiophobia was evaluated using the Tampa Scale for Kinesiophobia (TSK), quality of life was assessed via the Scoliosis Research Society-22 Questionnaire (SRS-22), and spinal balance was evaluated using full-spine radiographs (orthoroentgenograms). In the VRBR group, statistically significant improvements were observed in spinal mobility, MIP, MEP, physical activity level, TSK, and SRS-22 scores (p < 0.0001), as well as in coronal balance parameters including CSVL-C7PL (p = 0.041), sagittal vertical axis (SVA) (p = 0.01), and pelvic tilt (p < 0.0001) when compared to baseline. In contrast, no statistically significant improvements were found in any of the assessed parameters within the Control group (p > 0.05). Between-group comparisons revealed statistically significant improvements in favor of the VRBR group in spinal mobility (p = 0.048), MIP (p = 0.029), and physical activity levels (p < 0.01). The findings suggest that VR-based rehabilitation contributes positively to postoperative outcomes in AIS, with notable advantages in terms of spinal mobility, respiratory function, and physical activity.

Mechanical ventilation provides life-saving support to patients with respiratory failure, but inadequately tailored settings can lead to respiratory muscle dysfunction and poor patient outcomes. Surface electromyography (sEMG) offers a non-invasive modality to monitor respiratory muscle function. However, variability in acquisition setups limits the comparability of study findings and hinders broad clinical implementation.Therefore, we systematically appraised setup rationales and reporting quality in respiratory sEMG literature. The MEDLINE ALL, Embase, and Web of Science databases were systematically searched on 19 September 2024 for studies reporting original respiratory sEMG data in adults during spontaneous breathing. sEMG methodology was extracted in accordance with the reporting guidelines of the International Society of Electrophysiology and Kinesiology and analyzed by target muscle and medical domain. 240 out of 402 unique articles were included. The diaphragm was the most studied respiratory muscle (61%) with 48 unique setups out of 160 descriptions. Diaphragm setups with small inter-electrode distances (IEDs) were most common (n = 138, 86%). Large IED setups were predominantly applied in ICU (n = 8, 36%) and COPD (n = 5, 23%) populations. Setups for non-diaphragmatic respiratory muscles typically featured one or two dominant positions grounded in methodological studies. Reporting quality was low with a median of 5 out of 10 recommended items documented. This review reveals substantial diversity of diaphragm sEMG setups, reflecting differences in clinical contexts and study populations. The setups for extra-diaphragmatic muscles were more consistent and methodologically grounded. Muscle- and context-specific guidelines are essential to improve consistency and support clinical implementation of respiratory sEMG.

Traumatic rib fractures in high-risk patients present significant challenges in pain management, with inadequate analgesia leading to pulmonary complications, prolonged hospitalization, and increased morbidity. Conventional pain management strategies, including opioid-based regimens and catheter-based regional anesthesia, have undesirable side effects and limited duration analgesia. Cryoneurolysis overcomes many of these limitations and provides more sustained analgesia that better aligns with the expected prolonged pain trajectory of traumatic rib fractures. This brief technical report and case series details a description of our ultrasound technique we employ for percutaneous cryoneurolysis of intercostal nerves to achieve potent analgesia for traumatic rib fractures. We describe five cases of severe, high-risk traumatic rib fractures, as defined by a Rib Fracture Score >6 and STUMBL Score ≥26, who received ultrasound-guided, percutaneous cryoneurolysis of intercostal nerves for analgesia. Following cryoneurolysis, all patients showed significant clinical improvements, including better pain scores, reduced opioid consumption, rapid weaning from supplemental oxygen, and accelerated rehabilitation toward hospital discharge. Ultrasound-guided, percutaneous cryoneurolysis represents a promising, minimally invasive technique for managing pain associated with traumatic rib fractures in high-risk patients. The procedure offers sustained analgesia, improved respiratory function, and reduced systemic analgesic requirements while maintaining a favorable risk-benefit profile.

Mitochondria contain their own DNA (mtDNA), which is essential for respiratory function. Multiple copies of mtDNA are assembled into dot-like structures called nucleoids. Nucleoids move dynamically within mitochondria, and their size and distribution are influenced by mitochondrial membrane fission and fusion. However, the molecular mechanisms and their pathophysiological significance, particularly in vivo, remain largely unknown. Here, we identify a novel role for ubiquinone, as well as natural quinones lacking electron-carrying capacity, in the organization of nucleoids and respiratory complexes, independent of their conventional roles. These quinones facilitate the association and packaging of mtDNA on the cardiolipin-enriched mitochondrial inner membrane. This quinone-dependent maintenance of nucleoids protects against mitochondrial dysfunction and heart failure induced by the anticancer drug doxorubicin. Our RNAi screen identifies a set of genes involved in mitochondrial diseases that exhibit nucleoid deformation, suggesting a novel therapeutic approach targeting mitochondrial nucleoids for various pathological conditions associated with mitochondrial dysfunction.

Background: Delayed reperfusion (DR) in myocardial ischemia contributes to significant cardiac injury, characterized by mitochondrial dysfunction, oxidative stress, and cardiomyocyte death. Mitochondrial respiratory complexes are essential for maintaining cardiac energy metabolism during DR. EN1, known to support mitochondrial function in neurons, has recently been suggested to regulate mitochondrial complexes. However, its role in cardiomyocytes and the underlying molecular mechanisms remain poorly defined. Methods: We evaluated EN1 expression in murine models of myocardial DR injury and hypoxia/reoxygenation (H/R)-treated primary cardiomyocytes. The functional role of EN1 was examined using cardiomyocyte-specific En1 knockout and overexpression mouse models. Myocardial injury, cardiac function, and mitochondrial respiratory complex expression were assessed. To elucidate the molecular mechanism, we conducted co-immunoprecipitation to identify protein interactions, and employed PGC-1α inhibition and TFAM knockdown to dissect downstream signaling. Results: EN1 was significantly upregulated in both mouse myocardium post-DR and cardiomyocytes post-H/R, with nuclear localization. Specific knockout of En1 in cardiomyocytes markedly aggravated DR-induced myocardial infarction, elevated cardiomyocyte apoptosis, and impaired left ventricular systolic function. Loss of EN1 disrupted mitochondrial structure and led to reduction in the expression of key mitochondrial respiratory complex subunits (including UQCRC2, SDHB, and NDUFB8) at both the transcript and protein levels. In contrast, cardiomyocyte-specific EN1 overexpression reduced myocardial infarct size, preserved mitochondrial respiratory complex integrity, and restored cardiac function after DR injury. Mechanistically, EN1 interacted with PGC-1α and promoted the transcription of nuclear-encoded respiratory complex genes, while simultaneously upregulating TFAM to enhance mitochondrial DNA transcription. Inhibition of PGC-1α or silencing of TFAM impaired these effects, confirming that EN1 mediates mitochondrial and cardioprotective effects through the PGC-1α/TFAM pathway. Conclusions: EN1 plays a crucial role in maintaining mitochondrial respiratory function and conferring resistance to DR-induced cardiac injury through the PGC-1α/TFAM signaling axis. These findings identify EN1 as a promising molecular target for improving mitochondrial function and cardiac outcomes in myocardial DR injury.

Abstract: Nanotechnology has emerged as a transformative platform in the management of chronic obstructive pulmonary disease (COPD), offering targeted, sustained, and patient-friendly therapeutic solutions. Engineered nanocarriers, including liposomes, solid lipid nanoparticles, dendrimers, nanoemulsions, and polymeric nanoparticles enable the precise delivery of bronchodilators, anti-inflammatory agents, gene therapies, and prodrugs directly to inflamed lung tissues. Surface modification with PEG or targeting ligands enhances mucus penetration, circulation time, and receptorspecific uptake while minimizing systemic exposure. Prodrug-loaded nanoparticles remain stable during inhalation and undergo site-specific activation in the diseased pulmonary environment, improving therapeutic efficacy and reducing off-target effects. Furthermore, regenerative medicine approaches, including nanoparticle-assisted stem cell delivery, have shown promise in promoting lung tissue repair and immunomodulation. In addition, an antioxidant nanoparticles, such as gold, cerium oxide, and zinc-based systems, effectively scavenge reactive oxygen species and reduce inflammation, addressing a key pathogenic mechanism in COPD. In vivo studies demonstrate improved lung function, reduced cytokine levels, and enhanced bioavailability using these nano-based strategies. Collectively, these advancements signify a paradigm shift in COPD treatment from broad symptom relief to precision-targeted molecular intervention. With further clinical translation, nanotechnology holds the potential to revolutionize disease management, restoring respiratory function and enhancing quality of life for millions of patients worldwide.

Perioperative hemorrhagic shock (HS) is fetal in thoracic surgery. We previously reported acute salutary effects of Liposome-encapsulated hemoglobin vesicle (HbV) on organ dysfunction, hemodynamic deterioration and lethal arrhythmogenic property assessed by optical mapping analysis (OMP) with Langendorff's method in rat pneumonectomy HS model. In the previous study, immediately after pneumonectomy, repetitive 50% blood hemorrhage and resuscitation were conducted. HbV-administration (HbV-group), washed red blood cell-administration (wRBC-group), and 5% albumin-administration (ALB-group) were studied (Figure 1). Since extensive phase I clinical trial of HbV has now successfully being performed, investigating the chronic effects of HbV are suggested to be important for conducting future phase II clinical trials. Thus, we investigated serial effect of HbV on mean systemic blood pressure (MSP), mean RV pressure (MRVP), LV function (LVEF) by UCG, arrhythmogenicity by OMP (action potential duration dispersion [APDd, ms] in LV) with EPS for lethal arrhythmias (VT/VF) induction, organ dysfunction (troponin I [cTnI], CPK, AST, ALT, compliment C3[C3a]) and oxygen arterial content (CaO2) for respiratory function as studying chronic effects and/or side effects of HbV in SD rats (n=118). Each parameter was measured at 2 hours (Figure 1), and 1 week, 2 weeks, 4 weeks after resuscitation from pneumonectomy HS (F/U, chronic phase). Since very few rats in ALB-group, and most rats in HbV- and wRBC-groups could survive in chronic phase (Figure 2), each parameter was measured in limited number of ALB-group and almost all HbV-group and wRBC-group at F/U. MSPs of survived rats maintained normal all F/U among 3 groups. MRVPs were compensated to normal ranges in all 3 groups over 4 weeks (54±5, 44±3, 31±4, 27±6 mmHg; P&lt;0.05). Except few survived ALB-group rats at F/U (impaired LVEF, cTnI, APDd, induced VF), Each parameter of survived rats in HbV-group and wRBC-group was normal at all 3 F/U phase (for example, data at 4 weeks) such as LVEF (91±4 vs. 92±3%), cTnI (0.09±0.1 vs. 0.06±0.08 ng/mL) and normal CPK, AST, ALT, C3a, as well as normal CaO2 (11±1.0 vs.11±1.5 ml/dl) and normal OMP findings with no VT/VF induced (Figure 3). Conclusions; Administration of HbV could have good prognosis in pneumonectomy with HS, not showing adverse effects of HbV. These findings are useful for conducting HbV human phase II clinical trials.

The effect of Baduanjin exercises on the functional capacity, respiratory function, and quality of life of patients with idiopathic pulmonary fibrosis: a randomized controlled trial

Introduction. Laryngeal cancer is an important malignancy of the head and neck, with an estimated incidence of 238,000 cases per year. The main risk factors are smoking, human papillomavirus infection, and exposure to occupational carcinogens. Treatment of laryngeal cancer with T1–2 includes surgery and radiation therapy, but both methods have disadvantages: there is a risk of relapse after radiation therapy, and functional impairment after surgery, which necessitates optimization of treatment methods. photodynamic therapy is a promising organ-preserving method based on the targeted destruction of tumor cells by activating the photosensitizer accumulated in them with visible red light. Materials and methods. The study analyzed the results of combined treatment with intraoperative photodynamic therapy in 74 patients with laryngeal cancer from 2017 to 2023. Inclusion criteria: morphologically confirmed squamous cell carcinoma of the larynx, T1–2 tumor extent and absence of distant metastases. patients were administered photosensitizer (chlorin E6) intravenously 3 hours before surgery. Surgical treatment included endolaryngeal or open laryngeal resections followed by intraoperative photodynamic therapy on the bed of the removed tumor. Oncological and functional results were then assessed for 24 months. Results. Local recurrence was recorded in 2 (2.7 %) patients in the 1 st year and in 3 (4.17 %) patients in the 2 nd year. Overall survival was 100 %, larynx preservation was 95.9 %. In the group with a positive resection margin ( n = 11), progression was noted in 2 patients. Respiratory, swallowing and vocal functions were restored in all patients. No complications associated with photodynamic therapy were registered. Conclusion. The high efficiency of a combined approach involving the use of intraoperative photodynamic therapy in early-stage laryngeal cancer has been demonstrated. This method has provided good oncological and functional results. In some cases, it allows you to avoid adjuvant radiation therapy, reduce the risk of complications and shorten the rehabilitation period. further studies of the long-term results of such a combined method will help assess the prospects for its implementation in clinical practice.

Long COVID affects multiple body systems, with the respiratory system being particularly vulnerable. This study aimed to analyze the lung ventilatory function and diffusion capacity of patients with severe SARS-CoV-2 pneumonia during a 24-month follow-up course. Ventilatory function and lung diffusion capacity were assessed 6, 12, 18, and 24months after hospital discharge. Ventilatory parameters, Diffusion Lung Carbon Monoxide (DLCO), and KCO (Carbon Monoxide transfer coefficient) normalization were defined as achieving values > 80% predicted. A total of 222 patients admitted to the Intensive Care Unit (ICU) at ASST Spedali Civili di Brescia, Brescia, Italy, were enrolled. Among the 172 patients who completed the study, 140 (63%) achieved normalization of ventilatory parameters, DLCO, and KCO. The median time to recovery was 4.5months, and the hazard ratio (HR) decreased by 2% for each year of age increase. The median time to normalize ventilatory parameters (VC, FVC, FEV1, FEV1/FVC, TLC, and KCO) was 1.5months, while the median time to alveolar volume (VA) normalization was 4.5months. Male gender reduces the odds of normalization for FEV1/FVC and VA. The median time to DLCO normalization was 9months, with HR reduced by 3.1% as each year of age increased and augmented by 226% in obese subjects. 24months after severe COVID pneumonia, 14% of patients had persistent ventilatory and/or diffusive defects. Our study documented that male sex, age, and obesity impact the odds of normalization of ventilatory function and diffusive capacity. These findings underline the chronic nature of lung damage following severe COVID-19 pneumonia and the need for long-term follow-ups.

Dogs are classified according to their total cephalic index into three biotypes: dolichocephalic, mesocephalic, and brachycephalic. The latter has emerged due to the deliberate selection of extreme phenotypic traits during breeding, which has intensified the expression of associated conformational defects and led to several medical disorders. The Brachycephalic Obstructive Airway Syndrome (BOAS) is a respiratory condition directly linked to these conformational traits. Dogs affected by BOAS present a wide range of clinical signs, including respiratory noise, exercise intolerance, syncope episodes, or even sudden death. This study aimed to evaluate craniofacial anatomical differences and similarities among dogs of different cephalic biotypes (dolichocephalic, mesocephalic, and brachycephalic) and to determine how two exercise tolerance tests—a 6 min walk and a 1000 m walk—influence physiological parameters. Eighty dogs from different breeds were included and classified according to their biotype. Morphometric data from the head, body, and limbs were obtained. Additionally, physiological parameters, including heart rate, respiratory rate, blood pressure, oxygen saturation, and rectal temperature, were evaluated before and after the tolerance tests. The results indicated that dogs tolerated both exercise tests. Dolichocephalic and mesocephalic dogs showed a greater tolerance to or greater respiratory adaptation during walking. Despite the brachycephalic biotype, a wide dispersion at a distance of 1000 m, indicating that those with a higher BOAS grade did not require emergency medical assistance during the tests. However, evidence of rostral shortening (&lt;38 mm), together with facial foreshortening and measurements ≥ 20 mm for necks, chest circumference, and nasal fold, suggested a higher risk of airway obstruction in brachycephalic dogs diagnosed with BOAS grades 2 and 3 compared to dolichocephalic and mesocephalic dogs. This anatomical conformation was associated with significant alterations in physiological parameters including heart rate, respiratory rate, oxygen saturation below 90%, and temperature, which did not return to baseline values 10 min post-exercise. This showed significant differences between the biotypes in the distance in the 1000 m test (H = 11.74; p = 0.0028) and between the subdivisions (p = 0.0389), where G3 covered less distance than G2 (699.1 m vs. 932.77 m. These findings suggest that extreme brachycephalic conformation impairs the respiratory function and leads to thermoregulatory inefficiency, potentially compromising the animals’ survival under physical stress. Moreover, the application of safe walking tests and non-invasive morphometric measurements is suggested to facilitate prompt diagnosis of BOAS.

Part of Russia's territory is located in cold and temperate climate zones, where people are constantly exposed to the risk of hypothermia and cryotrauma. When exposed to cold, general metabolic processes in the body are inhibited, leading to disruption of the central nervous system, respiratory and other vital functions of the body. Studies by many authors have shown that not a single functional system remains intact during acute hypothermia. Purpose of the study . To identify patterns of changes in central hemodynamics, cardiac activity, vascular parameters depending on the severity and period of general unintentional hypothermia. Research methods . The study included 26 patients of both genders, aged from 18 to 50 years – 2 groups of 13 patients – with mild and moderate (group 1) and with severe (group 2) degree of unintentional hypotermia. Results. In patients with severe hypothermia, a decrease in pulse arterial pressure was recorded from admission to day 7 of observation, compared to patients with mild hypothermia. A decrease in cardiac output was also recorded on the first day of severe hypothermia. Stroke volume and ejection rate were higher in patients with severe hypothermia compared to those with mild and moderate hypothermia. In patients with mild hypothermia, an increase in pulse wave velocity was observed on days 3 and 7 of observation, compared to day 1. Conclusion . The increase in stroke arterial pressure corresponds to adaptive changes in hemodynamics in the post-hypothermic period of general cold injury. In severe hypothermia, pulse pressure and cardiac output are lower, while stroke volume and ejection rate are higher, compared to mild hypothermia. Over time, an increase in pulse wave velocity was observed in patients with mild hypothermia.

The management of lower respiratory tract diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and bronchiectasis, poses a significant challenge, particularly in countries with high levels of air pollution, smoking habits, and high prevalence of infections. Cough, as one of the primary symptoms, serves as a protective mechanism of the body to maintain airway hygiene as well as unobstructed breathing. Therefore, cough should be managed appropriately to ensure efficient mucus expectoration, one way being through the use of mucolytic agents such as bromhexine. Themodern approaches to respiratory infection management emphasize the combination of pharmacological interventions and physiological support. Pharmacological therapy focuses on restoring respiratory function using rational treatment, including control of inflammation, managing mucus drainage, and the rational use of antibiotics. Physiological interventions such as pulmonary rehabilitation and smoking cessation have a substantial long-term impact on improving patients’ quality of life.

Effects of inspiratory muscle training on balance, trunk control, fear of falling, respiratory function, and quality of life in people with multiple sclerosis: a randomized controlled trial.

The effects of inspiratory muscle training on exercise tolerance in patients with post-covid-19 syndrome: a systematic review.

Cardiorespiratory monitoring methods are vital in clinical and personal healthcare contexts, continuously delivering comprehensive insights into patient health. Among them, electrical impedance tomography, a non-invasive imaging modality, uniquely enables spatially resolved, real-time monitoring of both cardiac and respiratory functions. However, separating cardiac and respiratory signals remains a challenge due to spectral and spatial overlap, heart-lung interactions and nonstationarity. Existing signal processing techniques face limitations in adaptiveness, harmonic overlap handling, and real-time feasibility, restricting their clinical adoption. This work introduces two novel adaptive model-based approaches derived from a harmonic framework inspired by source-filter theory: harmonic least-squares, a deterministic estimator; and harmonically-constrained filtering, which employs harmonic priors and noise covariance approximations towards optimal separation. These algorithms were systematically validated using extensive synthetic and real-world datasets across diverse clinical scenarios. Monte Carlo simulations with a dynamic synthesizer and machine learning surrogate models provided robust performance evaluations, with insights into algorithm behavior through accumulated local effect plots. The proposed methods demonstrated superior performance compared to state-of-the-art approaches and achieved real-time processing capability, making them promising for integration into medical devices. Despite these advancements, further improvements in noise modelling, performance guarantees, and processing efficiency remain potential areas for future development.

Effects of diaphragmatic manual therapy on respiratory function in patients with non-specific low back pain: A randomized control trial.

Retrosternal tunnel creation using laparoscopy combined with modified cervical dissection in McKeown esophagectomy.

Impact of therapeutic education on knowledge, adherence, asthma control, and respiratory function in asthmatic patients: A 6-month follow-up