Physiological effects of high-flow nasal cannula oxygen therapy after extubation: a randomized crossover study.

BACKGROUND: Prophylactic high-flow nasal cannula (HFNC) oxygen therapy can decrease the risk of extubation failure. It is frequently used in the postextubation phase alone or in combination with noninvasive ventilation. However, its physiological effects in this setting have not been thoroughly investigated. The aim of this study was to determine comprehensively the effects of HFNC applied after extubation on respiratory effort, diaphragm activity, gas exchange, ventilation distribution, and cardiovascular biomarkers. METHODS: This was a prospective randomized crossover physiological study in critically ill patients comparing 1 h of HFNC versus 1 h of standard oxygen after extubation. The main inclusion criteria were mechanical ventilation for at least 48 h due to acute respiratory failure, and extubation after a successful spontaneous breathing trial (SBT). We measured respiratory effort through esophageal/transdiaphragmatic pressures, and diaphragm electrical activity (ΔEAdi). Lung volumes and ventilation distribution were estimated by electrical impedance tomography. Arterial and central venous blood gases were analyzed, as well as cardiac stress biomarkers. RESULTS: We enrolled 22 patients (age 59 ± 17 years; 9 women) who had been intubated for 8 ± 6 days before extubation. Respiratory effort was significantly lower with HFNC than with standard oxygen therapy, as evidenced by esophageal pressure swings (5.3 [4.2-7.1] vs. 7.2 [5.6-10.3] cmH2O; p < 0.001), pressure-time product (85 [67-140] vs. 156 [114-238] cmH2O*s/min; p < 0.001) and ΔEAdi (10 [7-13] vs. 14 [9-16] µV; p = 0.022). In addition, HFNC induced increases in end-expiratory lung volume and PaO2/FiO2 ratio, decreases in respiratory rate and ventilatory ratio, while no changes were observed in systemic hemodynamics, Troponin T, or in amino-terminal pro-B-type natriuretic peptide. CONCLUSIONS: Prophylactic application of HFNC after extubation provides substantial respiratory support and unloads respiratory muscles. Trial registration January 15, 2021. NCT04711759.

Assessment of activities and participation of people by rehabilitation-focused clinical registries: a systematic scoping review.

INTRODUCTION: Rehabilitation is considered a key intervention in health care. Clinical registries, defined as an organized system that uses observational methods to collect information to assess specific outcomes in a defined population, can contribute to assessing the impact of the rehabilitation intervention. This review aims to identify and describe rehabilitation-specific registry systems with an emphasis on identifying outcomes that enable the assessment of vital areas and activities of daily living. EVIDENCE ACQUISITION: A systematic scoping review was conducted. A systematic search was conducted up to August 2022 in MEDLINE/PubMed, Embase, Cochrane Library, Epistemonikos, and other search resources. Studies related to rehabilitation registries presented data on people with health problems that could limit their functioning were selected. The inclusion of studies/clinical registries was not limited by methodological design, year of publication, country, or language. The unit of analysis was rehabilitation registries. The measurement instruments used to assess the outcomes were explored to estimate the domain assessed from the vital areas related to functioning and disability as described by the International Classification of Functioning, Disability and Health (ICF). The vital areas were classified according to activities of daily living (ADLs). EVIDENCE SYNTHESIS: Seventy-one registries in rehabilitation were identified. The registries included a median of 3 (IQR 2-5) assessment instruments designed to assess the impact of different rehabilitation programs. In total, 137 different assessment scales or instruments were identified. Each rehabilitation registry assessed 6 (IQR 2-8) domains of the ICF, and 15.4% of registries assessed all domains. The most assessed domain was "Mobility" (89.7%), and the least assessed was "General Tasks and Demands" (25.6%). In addition, 92.3% of rehabilitation registries assessed basic ADLs, 76.9% advanced ADLs, and 71.8% instrumental ADLs. CONCLUSIONS: Although clinical registries do not claim to directly assess the impact of rehabilitation programs on people's functioning according to the ICF framework, it was identified that a low percentage of them assessed the nine vital areas through different outcome assessment instruments. However, most rehabilitation registries directly or indirectly assess some basic, instrumental, and advanced ADLs. The findings of this review highlight the need to improve the design of clinical registries focused on assessing the impact of rehabilitation programs to assess people in all areas of their lives.

Lung aeration estimated by chest electrical impedance tomography and lung ultrasound during extubation.

BACKGROUND: This study hypothesized that patients with extubation failure exhibit a loss of lung aeration and heterogeneity in air distribution, which could be monitored by chest EIT and lung ultrasound. Patients at risk of extubation failure were included after a successful spontaneous breathing trial. Lung ultrasound [with calculation of lung ultrasound score (LUS)] and chest EIT [with calculation of the global inhomogeneity index, frontback center of ventilation (CoV), regional ventilation delay (RVD) and surface available for ventilation] were performed before extubation during pressure support ventilation (H0) and two hours after extubation during spontaneous breathing (H2). EIT was then repeated 6 h (H6) after extubation. EIT derived indices and LUS were compared between patients successfully extubated and patients with extubation failure. RESULTS: 40 patients were included, of whom 12 (30%) failed extubation. Before extubation, when compared with patients with successful extubation, patients who failed extubation had a higher LUS (19 vs 10, p = 0.003) and a smaller surface available for ventilation (352 vs 406 pixels, p = 0.042). After extubation, GI index and LUS were higher in the extubation failure group, whereas the surface available for ventilation was lower. The RVD and the CoV were not different between groups. CONCLUSION: Before extubation, a loss of lung aeration was observed in patients who developed extubation failure afterwards. After extubation, this loss of lung aeration persisted and was associated with regional lung ventilation heterogeneity. Trial registration Clinical trials, NCT04180410, Registered 27 November 2019-prospectively registered, https://clinicaltrials.gov/ct2/show/NCT04180410 .

Factors Associated With Accidental Decannulation in Tracheostomized Children.

BACKGROUND: Tracheostomy has many benefits for pediatric patients in the ICU, but it is also associated with complications. Accidental decannulation (AD) is a frequent complication and cause of mortality in this population. Our study aimed to determine the factors associated with AD in tracheostomized pediatric subjects. METHODS: This was a case-control study with 1:2 allocation ratio. Participants were tracheostomized children hospitalized in a prolonged mechanical ventilation hospital between 2013-2018. Each child who experienced decannulation during the study period was included as a case at the time of the event. Controls were obtained from the same population and were defined as subjects without an AD event during the same period. RESULTS: One hundred forty patients were hospitalized at Josefina Martinez Hospital at the time, of whom 41 were selected as cases and 82 as controls. Median (interquartile range) age was 20 (12-36) months, being 60% male. The median time from tracheostomy placement to AD event was 364 (167-731) d. Eighty-four percent of subjects were mechanically ventilated. AD mainly occurred by self-decannulation (53.7%). The risk of AD was higher in children who reached the midline in a sitting position (odds ratio 9.5 [95% CI 1.59-53.90]), inner diameter (ID) tracheostomy tube size ≤ 4.0 mm (odds ratio 5.18 [95% CI 1.41-19.06]), and who had been hospitalized in hospital rooms with a low ratio of nursing staff for each subject (1 nurse to 4 subjects) (odds ratio 4.48 [95% CI 1.19-16.80]). CONCLUSIONS: Factors associated with a higher risk of AD in tracheostomized children included the ability to reach the midline in a sitting position, the use of a smaller tracheostomy tube (≤ 4.0 mm ID), and lower supervision from staff.

Assessment of redundancy, methodological and reporting quality, and potential discrepancies of results of systematic reviews of early mobilisation of critically ill adults: a meta-research protocol.

INTRODUCTION: Several systematic reviews (SRs) have been conducted to determine the effectiveness of early mobilisation in critically ill adults with heterogeneous methodology and results. Redundancy in conducting SRs, unclear justification when leading new SRs or updating, and discordant results of SRs on the same research question may generate research waste that makes it difficult for clinicians to keep up to date with the best available evidence. This meta-research aims to assess the redundancy, methodological and reporting quality, and potential reasons for discordance in the results reported by SRs conducted to determine the effectiveness of early mobilisation in critically ill adult patients. METHODS AND ANALYSIS: A meta-research of early mobilisation SRs in critically ill adult patients will be conducted. A search of MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCOhost), Cochrane Library, Epistemonikos and other search resources will be conducted. Two independent reviewers will perform study selection, data extraction and quality appraisal. Discrepancies will be resolved by consensus or a third reviewer. The redundancy of SRs will be assessed by the degree of overlap of primary studies. In addition, the justification for conducting new SRs will be evaluated with the 'Evidence-Based Research' framework. The methodological quality of the SRs will be assessed with the A MeaSurement Tool to Assess systematic Reviews 2 tool, and the quality of the reports through compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. To assess the potential reasons for discordance in the results of the SRs considering divergence in results and their interpretation. ETHICS AND DISSEMINATION: As meta-research, this study does not involve the participation of people whose rights may be violated. However, this overview will be developed rigorously and systematically to achieve valid and reliable results. The findings of this meta-research study will be presented at conferences and published in a peer-reviewed journal related to rehabilitation, critical care or research methodology. TRIAL REGISTRATION NUMBER: osf.io/kxwq9.

Eccentric Contractions of the Diaphragm During Mechanical Ventilation.

Diaphragm dysfunction is a highly prevalent phenomenon in patients receiving mechanical ventilation, mainly due to ventilatory over-assistance and the development of diaphragm disuse atrophy. Promoting diaphragm activation whenever possible and facilitating an adequate interaction between the patient and the ventilator is encouraged at the bedside to avoid myotrauma and further lung injury. Eccentric contractions of the diaphragm are defined as muscle activation while muscle fibers are lengthening within the exhalation phase. There is recent evidence that suggests that eccentric activation of the diaphragm is very frequent and may occur during post-inspiratory activity or under different types of patient-ventilator asynchronies, which include ineffective efforts, premature cycling, and reverse triggering. The consequences of this eccentric contraction of the diaphragm may have opposite effects, depending on the level of breathing effort. For instance, during high or excessive effort, eccentric contractions can result in diaphragm dysfunction and injured muscle fibers. Conversely, when eccentric contractions of the diaphragm occur along with low breathing effort, a preserved diaphragm function, better oxygenation, and more aerated lung tissue are observed. Despite this controversial evidence, evaluating the level of breathing effort at the bedside seems crucial and is highly recommended to optimize ventilatory therapy. The impact of eccentric contractions of the diaphragm on the patient's outcome remains to be elucidated.

Effects of the First Spontaneous Breathing Trial in Children With Tracheostomy and Long-Term Mechanical Ventilation.

BACKGROUND: Weaning and liberation from mechanical ventilation in pediatric patients with tracheostomy and long-term mechanical ventilation constitute a challenging process due to diagnosis heterogeneity and significant variability in the clinical condition. We aimed to evaluate the physiological response during the first attempt of a spontaneous breathing trial (SBT) and to compare variables in subjects who failed or passed the SBT. METHODS: This was a prospective observational study in tracheostomized children with long-term mechanical ventilation admitted to the Hospital Josefina Martinez, Santiago, Chile, between 2014-2020. Cardiorespiratory variables such as breathing pattern, use of accessory respiratory muscles, heart rate, breathing frequency, and oxygen saturation were registered at baseline and throughout a 2-h SBT with or without positive pressure depending on an SBT protocol. Comparison of demographic and ventilatory variables between groups (SBT failure and success) was performed. RESULTS: A total of 48 subjects were analyzed (median [IQR] age of 20.5 [17.0-35.0] months, 60% male). Chronic lung disease was the primary diagnosis in 60% of subjects. Eleven (23%) total subjects failed the SBT (< 2 h), with an average failure time of 69 ± 29 min. Subjects who failed the SBT had a significantly higher breathing frequency, heart rate, and end-tidal CO2 than subjects who succeeded (P < .001). In addition, subjects who failed the SBT had significantly shorter duration of mechanical ventilation before the SBT, higher proportion unassisted SBT, and higher rate of deviation SBT protocol in comparison with subjects who succeeded. CONCLUSIONS: Conducting an SBT to evaluate the tolerance and cardiorespiratory response in tracheostomized children with long-term mechanical ventilation is feasible. Time on mechanical ventilation before the first attempt and type of SBT (with or without positive pressure) could be associated with SBT failure.

The COVID-19 Driving Force: How It Shaped the Evidence of Non-Invasive Respiratory Support.

During the COVID-19 pandemic, the use of non-invasive respiratory support (NIRS) became crucial in treating patients with acute hypoxemic respiratory failure. Despite the fear of viral aerosolization, non-invasive respiratory support has gained attention as a way to alleviate ICU overcrowding and reduce the risks associated with intubation. The COVID-19 pandemic has led to an unprecedented increased demand for research, resulting in numerous publications on observational studies, clinical trials, reviews, and meta-analyses in the past three years. This comprehensive narrative overview describes the physiological rationale, pre-COVID-19 evidence, and results of observational studies and randomized control trials regarding the use of high-flow nasal oxygen, non-invasive mechanical ventilation, and continuous positive airway pressure in adult patients with COVID-19 and associated acute hypoxemic respiratory failure. The review also highlights the significance of guidelines and recommendations provided by international societies and the need for further well-designed research to determine the optimal use of NIRS in treating this population.

Effectiveness of physical rehabilitation interventions in critically ill patients-A protocol for an overview of systematic reviews.

INTRODUCTION: Adult and pediatric patients admitted to intensive care units (ICUs) requiring invasive ventilatory support, sedation, and muscle blockade may present neuromusculoskeletal deterioration. Different physical rehabilitation interventions have been studied to evaluate their effectiveness in improving critically ill patients' outcomes. Given that many published systematic reviews (SRs) aims to determine the effectiveness of different types of physical rehabilitation interventions, it is necessary to group them systematically and assess the methodological quality of SRs to help clinicians make better evidence-based decisions. This overview of SRs (OoSRs) aims to map the existing evidence and to determine the effectiveness of physical rehabilitation interventions to improve neuromusculoskeletal function and other clinical outcomes in adult and pediatric critically ill patients. METHODS: An OoSRs of randomized and non-randomized clinical trials involving critically ill adult and pediatric patients receiving physical rehabilitation intervention will be conducted. A sensitive search of MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCOhost), Cochrane Library, Epistemonikos, and other search resources will be conducted. Two independent reviewers will conduct study selection, data extraction, and methodological quality assessment. Discrepancies will be resolved by consensus or a third reviewer. The degree of overlap of studies will be calculated using the corrected covered area. The methodological quality of the SRs will be measured using the AMSTAR-2 tool. The GRADE framework will report the certainty of evidence by selecting the "best" SR for each physical rehabilitation intervention and outcome. DISCUSSION: The findings of this overview are expected to determine the effectiveness and safety of physical rehabilitation interventions to improve neuromusculoskeletal function in adult and pediatric critically ill patients based on a wide selection of the best available evidence and to determine the knowledge gaps in this topic by mapping and assessing the methodological quality of published SRs. REGISTRATION NUMBER: CRD42023389672.

Effectiveness of neuromuscular electrostimulation in COPD subjects on mechanical ventilation. A systematic review and meta-analysis.

OBJECTIVE: To estimate the effectiveness of Neuromuscular Electrostimulation (NMES) in adults with COPD undergoing MV. METHOD: A sensitive search was performed in MEDLINE, Embase, CENTRAL, CINAHL and other resources. Randomized Controlled Clinical Trials (RCTs) or non-RCTs that enrolled adults with COPD on MV due to an exacerbation of their disease were included. Two independent reviewers screened, extracted information, and assessed the risk of bias (RoB 2 tool) and the certainty of evidence (GRADE approach) from the included studies. RESULTS: Four RCTs (144 participants) were included. Subjects who underwent NMES were able to move from bed to chair independently in less time (MD = 4.98 days less; 95% CI -8.55 to -1.47; 2 RCTs; low certainty of the evidence) and they were fewer days on MV (MD = 2.89 days less; 95% CI -4.58 to -1.21); 3 RCTs; low certainty of the evidence) than the control group. However, the effect of NMES on muscle strength is unclear (very low certainty of the evidence). CONCLUSIONS: NMES may improve functional independence and decrease MV time in adults with COPD; however, its effectiveness on muscle strength is uncertain. More and better RCTs are needed to determine with greater certainty the effectiveness of NMES in this population.

Spontaneous breathing promotes lung injury in an experimental model of alveolar collapse.

Vigorous spontaneous breathing has emerged as a promotor of lung damage in acute lung injury, an entity known as "patient self-inflicted lung injury". Mechanical ventilation may prevent this second injury by decreasing intrathoracic pressure swings and improving regional air distribution. Therefore, we aimed to determine the effects of spontaneous breathing during the early stage of acute respiratory failure on lung injury and determine whether early and late controlled mechanical ventilation may avoid or revert these harmful effects. A model of partial surfactant depletion and lung collapse was induced in eighteen intubated pigs of 32 ±4 kg. Then, animals were randomized to (1) SB-group: spontaneous breathing with very low levels of pressure support for the whole experiment (eight hours), (2) Early MV-group: controlled mechanical ventilation for eight hours, or (3) Late MV-group: first half of the experiment on spontaneous breathing (four hours) and the second half on controlled mechanical ventilation (four hours). Respiratory, hemodynamic, and electric impedance tomography data were collected. After the protocol, animals were euthanized, and lungs were extracted for histologic tissue analysis and cytokines quantification. SB-group presented larger esophageal pressure swings, progressive hypoxemia, lung injury, and more dorsal and inhomogeneous ventilation compared to the early MV-group. In the late MV-group switch to controlled mechanical ventilation improved the lung inhomogeneity and esophageal pressure swings but failed to prevent hypoxemia and lung injury. In a lung collapse model, spontaneous breathing is associated to large esophageal pressure swings and lung inhomogeneity, resulting in progressive hypoxemia and lung injury. Mechanical ventilation prevents these mechanisms of patient self-inflicted lung injury if applied early, before spontaneous breathing occurs, but not when applied late.

A deep look into the rib cage compression technique in mechanically ventilated patients: a narrative review. / Desvendando a técnica de compressão torácica em pacientes em ventilação mecânica: uma revisão narrativa.

Defective management of secretions is one of the most frequent complications in invasive mechanically ventilated patients. Clearance of secretions through chest physiotherapy is a critical aspect of the treatment of these patients. Manual rib cage compression is one of the most practiced chest physiotherapy techniques in ventilated patients; however, its impact on clinical outcomes remains controversial due to methodological issues and poor understanding of its action. In this review, we present a detailed analysis of the physical principles involved in rib cage compression technique performance, as well as the physiological effects observed in experimental and clinical studies, which show that the use of brief and vigorous rib cage compression, based on increased expiratory flows (expiratory-inspiratory airflow difference of > 33L/minute), can improve mucus movement toward the glottis. On the other hand, the use of soft and gradual rib cage compression throughout the whole expiratory phase does not impact the expiratory flows, resulting in ineffective or undesired effects in some cases. More physiological studies are needed to understand the principles of the rib cage compression technique in ventilated humans. However, according to the evidence, rib cage compression has more potential benefits than risks, so its implementation should be promoted.

O manejo deficiente das secreções é uma das complicações mais frequentes em pacientes em ventilação mecânica invasiva. A depuração das secreções por meio da fisioterapia respiratória é um aspecto crítico do tratamento desses pacientes. A compressão torácica manual é uma das técnicas de fisioterapia respiratória mais praticadas em pacientes ventilados, mas seu impacto nos desfechos clínicos permanece controverso devido a questões metodológicas e ao pouco conhecimento sobre sua ação. Nesta revisão, apresenta-se uma análise detalhada dos princípios físicos envolvidos na execução da técnica de compressão torácica. Também investigam-se os efeitos fisiológicos observados em estudos experimentais e clínicos, que mostram que o uso de compressão torácica curta e vigorosa, baseada no aumento de fluxos expiratórios (diferença de fluxo aéreo inspiratório-expiratório > 33L/minuto), pode melhorar o movimento do muco em direção à glote. Por outro lado, o uso de compressão torácica suave e gradual ao longo de toda a fase expiratória não afeta os fluxos expiratórios, resultando em efeitos ineficazes ou indesejados em alguns casos. Mais estudos fisiológicos são necessários para entender os princípios da técnica de compressão torácica em pacientes ventilados. No entanto, de acordo com as evidências, a compressão torácica tem mais benefícios potenciais do que riscos, o que incentiva sua implementação.

Desvendando a técnica de compressão torácica em pacientes em ventilação mecânica: uma revisão narrativa / A deep look into the rib cage compression technique in mechanically ventilated patients: a narrative review

RESUMO O manejo deficiente das secreções é uma das complicações mais frequentes em pacientes em ventilação mecânica invasiva. A depuração das secreções por meio da fisioterapia respiratória é um aspecto crítico do tratamento desses pacientes. A compressão torácica manual é uma das técnicas de fisioterapia respiratória mais praticadas em pacientes ventilados, mas seu impacto nos desfechos clínicos permanece controverso devido a questões metodológicas e ao pouco conhecimento sobre sua ação. Nesta revisão, apresenta-se uma análise detalhada dos princípios físicos envolvidos na execução da técnica de compressão torácica. Também investigam-se os efeitos fisiológicos observados em estudos experimentais e clínicos, que mostram que o uso de compressão torácica curta e vigorosa, baseada no aumento de fluxos expiratórios (diferença de fluxo aéreo inspiratório-expiratório > 33L/minuto), pode melhorar o movimento do muco em direção à glote. Por outro lado, o uso de compressão torácica suave e gradual ao longo de toda a fase expiratória não afeta os fluxos expiratórios, resultando em efeitos ineficazes ou indesejados em alguns casos. Mais estudos fisiológicos são necessários para entender os princípios da técnica de compressão torácica em pacientes ventilados. No entanto, de acordo com as evidências, a compressão torácica tem mais benefícios potenciais do que riscos, o que incentiva sua implementação.

ABSTRACT Defective management of secretions is one of the most frequent complications in invasive mechanically ventilated patients. Clearance of secretions through chest physiotherapy is a critical aspect of the treatment of these patients. Manual rib cage compression is one of the most practiced chest physiotherapy techniques in ventilated patients; however, its impact on clinical outcomes remains controversial due to methodological issues and poor understanding of its action. In this review, we present a detailed analysis of the physical principles involved in rib cage compression technique performance, as well as the physiological effects observed in experimental and clinical studies, which show that the use of brief and vigorous rib cage compression, based on increased expiratory flows (expiratory-inspiratory airflow difference of > 33L/minute), can improve mucus movement toward the glottis. On the other hand, the use of soft and gradual rib cage compression throughout the whole expiratory phase does not impact the expiratory flows, resulting in ineffective or undesired effects in some cases. More physiological studies are needed to understand the principles of the rib cage compression technique in ventilated humans. However, according to the evidence, rib cage compression has more potential benefits than risks, so its implementation should be promoted.

Effectiveness of neuromuscular electrostimulation in COPD subjects on mechanical ventilation. A systematic review and meta-analysis

Abstract Objective: To estimate the effectiveness of Neuromuscular Electrostimulation (NMES) in adults with COPD undergoing MV. Method: A sensitive search was performed in MEDLINE, Embase, CENTRAL, CINAHL and other resources. Randomized Controlled Clinical Trials (RCTs) or non-RCTs that enrolled adults with COPD on MV due to an exacerbation of their disease were included. Two independent reviewers screened, extracted information, and assessed the risk of bias (RoB 2 tool) and the certainty of evidence (GRADE approach) from the included studies. Results: Four RCTs (144 participants) were included. Subjects who underwent NMES were able to move from bed to chair independently in less time (MD = 4.98 days less; 95% CI -8.55 to -1.47; 2 RCTs; low certainty of the evidence) and they were fewer days on MV (MD = 2.89 days less; 95% CI -4.58 to -1.21); 3 RCTs; low certainty of the evidence) than the control group. However, the effect of NMES on muscle strength is unclear (very low certainty of the evidence). Conclusions: NMES may improve functional independence and decrease MV time in adults with COPD; however, its effectiveness on muscle strength is uncertain. More and better RCTs are needed to determine with greater certainty the effectiveness of NMES in this population.

Acute lung injury secondary to hydrochloric acid instillation induces small airway hyperresponsiveness.

BACKGROUND: Acute respiratory distress syndrome (ARDS) is a severe form of respiratory failure characterized by altered lung mechanics and poor oxygenation. Bronchial hyperresponsiveness has been reported in ARDS survivors and animal models of acute lung injury. Whether this hyperreactivity occurs at the small airways or not is unknown. OBJECTIVE: To determine ex-vivo small airway reactivity in a rat model of acute lung injury (ALI) by hydrochloric acid (HCl) instillation. METHODS: Twelve anesthetized rats were connected to mechanical ventilation for 4-hour, and randomly allocated to either ALI group (HCl intratracheal instillation; n=6) or Sham (intratracheal instillation of 0.9% NaCl; n=6). Oxygenation was assessed by arterial blood gases. After euthanasia, tissue samples from the right lung were harvested for histologic analysis and wet-dry weight ratio assessment. Precision cut lung slice technique (100-200 µm diameter) was applied in the left lung to evaluate ex vivo small airway constriction in response to histamine and carbachol stimulation, using phase-contrast video microscopy. RESULTS: Rats from the ALI group exhibited hypoxemia, worse histologic lung injury, and increased lung wet-dry weight ratio as compared with the sham group. The bronchoconstrictor responsiveness was significantly higher in the ALI group, both for carbachol (maximal contraction of 84.5±2.5% versus 61.4±4.2% in the Sham group, P<0.05), and for histamine (maximal contraction of 78.6±5.3% versus 49.6±5.3% in the Sham group, P<0.05). CONCLUSION: In an animal model of acute lung injury secondary to HCL instillation, small airway hyperresponsiveness to carbachol and histamine is present. These results may provide further insight into the pathophysiology of ARDS.

Effectiveness of Telerehabilitation in Physical Therapy: A Rapid Overview.

OBJECTIVE: The purpose of this article was to summarize the available evidence from systematic reviews on telerehabilitation in physical therapy. METHODS: We searched Medline/PubMed, EMBASE, and Cochrane Library databases. In addition, the records in PROSPERO and Epistemonikos and PEDro were consulted. Systematic reviews of different conditions, populations, and contexts-where the intervention to be evaluated is telerehabilitation by physical therapy-were included. The outcomes were clinical effectiveness depending on specific condition, functionality, quality of life, satisfaction, adherence, and safety. Data extraction and risk of bias assessment were carried out by a reviewer with non-independent verification by a second reviewer. The findings are reported qualitatively in the tables and figures. RESULTS: Fifty-three systematic reviews were included, of which 17 were assessed as having low risk of bias. Fifteen reviews were on cardiorespiratory rehabilitation, 14 on musculoskeletal conditions, and 13 on neurorehabilitation. The other 11 reviews addressed other types of conditions and rehabilitation. Thirteen reviews evaluated with low risk of bias showed results in favor of telerehabilitation versus in-person rehabilitation or no rehabilitation, while 17 reported no differences between the groups. Thirty-five reviews with unclear or high risk of bias showed mixed results. CONCLUSIONS: Despite the contradictory results, telerehabilitation in physical therapy could be comparable with in-person rehabilitation or better than no rehabilitation for conditions such as osteoarthritis, low-back pain, hip and knee replacement, and multiple sclerosis and also in the context of cardiac and pulmonary rehabilitation. It is imperative to conduct better quality clinical trials and systematic reviews. IMPACT: Providing the best available evidence on the effectiveness of telerehabilitation to professionals, mainly physical therapists, will impact the decision-making process and therefore yield better clinical outcomes for patients, both in these times of the COVID-19 pandemic and in the future. The identification of research gaps will also contribute to the generation of relevant and novel research questions.

Disfunción Diafragmática en Ventilación Mecánica: Evaluación e Implicancias Clínicas / Diaphragmatic Dysfunction in Mechanical Ventilation: Evaluation and Clinical Implications

La debilidad diafragmática es un problema relevante en pacientes admitidos a la unidad de cuidados intensivos (UCI). Su presencia ha sido asociada a mayor tiempo en ventilación mecánica, weaning dificultoso, mayor riesgo de readmisión hospitalaria y mayor mortalidad. Las causas de esta debilidad son múltiples incluyendo factores relacionados a la severidad de la enfermedad, las intervenciones en la UCI y el uso de ventilación mecánica, termino conocido como miotrauma. Se han propuesto cuatro diferentes mecanismos de miotrauma relacionados a la sobre asistencia ventilatoria, baja asistencia ventilatoria, ocurrencia de contracciones diafragmáticas excéntricas y efecto de la presión espiratoria al final de espiración. Una adecuada evaluación y monitoreo de la función diafragmática es, por lo tanto, un aspecto clave que debe ser realizado al lado de la cama del paciente. La prueba de referencia para medir la función del diafragma es la presión transdiafragmática calculada como la diferencia entre la presión gástrica y presión esofágica. Adicionalmente, otras técnicas disponibles para la evaluación de la función del diafragma corresponden a la ecografía y la medición de la actividad eléctrica. Desde un punto de vista clínico, basado en la evidencia sobre disfunción diafragmática en los pacientes ventilados mecánicamente, uno de los principales desafíos actuales es poder buscar estrategias ventilatorias que incorporen protección diafragmática mientras se mantiene una ventilación protectora pulmonar. En este sentido, favorecer un nivel de esfuerzo inspiratorio adecuado junto con optimizar la interacción entre el paciente y el ventilador constituyen los principales objetivos de una ventilación diafragmática protectora.

Diaphragm weakness is a relevant problem in patients admitted to the intensive care unit (ICU). Its presence has been associated with prolonged mechanical ventilation, difficult weaning, higher risk of hospital readmission, and higher mortality. The causes of this weakness are multiple, including factors related to the severity of the disease, ICU interventions and the use of mechanical ventilation, a term known as myotrauma. Four different mechanisms of myotrauma have been proposed: 1. Ventilator over-assistance; 2. Ventilator under-assistance: 3. Eccentric diaphragm contractions: and 4. Excessive end-expiratory shortening by high PEEP. An adequate evaluation and monitoring of diaphragmatic function is, therefore, a key aspect that must be performed at the patient's bedside. The gold standard for measuring diaphragm function is transdiaphragmatic pressure calculated as the difference between gastric pressure and esophageal pressure. Furthermore, other techniques available for the evaluation of diaphragm function correspond to ultrasound and the measurement of its electrical activity. From a clinical point of view, based on diaphragmatic dysfunction evidence in mechanically ventilated patients, the main current challenge consists in applying ventilatory strategies that incorporate diaphragmatic protection while maintaining lung protective ventilation. In this sense, favoring an adequate level of inspiratory effort together with optimizing the interaction between the patient and the ventilator are the main objectives of diaphragm protective ventilation.

The Challenge by Multiple Environmental and Biological Factors Induce Inflammation in Aging: Their Role in the Promotion of Chronic Disease.

The aging process is driven by multiple mechanisms that lead to changes in energy production, oxidative stress, homeostatic dysregulation and eventually to loss of functionality and increased disease susceptibility. Most aged individuals develop chronic low-grade inflammation, which is an important risk factor for morbidity, physical and cognitive impairment, frailty, and death. At any age, chronic inflammatory diseases are major causes of morbimortality, affecting up to 5-8% of the population of industrialized countries. Several environmental factors can play an important role for modifying the inflammatory state. Genetics accounts for only a small fraction of chronic-inflammatory diseases, whereas environmental factors appear to participate, either with a causative or a promotional role in 50% to 75% of patients. Several of those changes depend on epigenetic changes that will further modify the individual response to additional stimuli. The interaction between inflammation and the environment offers important insights on aging and health. These conditions, often depending on the individual's sex, appear to lead to decreased longevity and physical and cognitive decline. In addition to biological factors, the environment is also involved in the generation of psychological and social context leading to stress. Poor psychological environments and other sources of stress also result in increased inflammation. However, the mechanisms underlying the role of environmental and psychosocial factors and nutrition on the regulation of inflammation, and how the response elicited for those factors interact among them, are poorly understood. Whereas certain deleterious environmental factors result in the generation of oxidative stress driven by an increased production of reactive oxygen and nitrogen species, endoplasmic reticulum stress, and inflammation, other factors, including nutrition (polyunsaturated fatty acids) and behavioral factors (exercise) confer protection against inflammation, oxidative and endoplasmic reticulum stress, and thus ameliorate their deleterious effect. Here, we discuss processes and mechanisms of inflammation associated with environmental factors and behavior, their links to sex and gender, and their overall impact on aging.