Respiratory care最新文献

Individuals with classic asthma can present with wheezing, dyspnea, chest tightness, and/or cough. Notably, cough can be the main or only symptom of asthma, termed cough variant asthma. Although there are numerous guidelines for asthma, the diagnosis and management of cough in asthma remain challenging because of its complex physiology. By definition, cough variant asthma excludes individuals with normal airway sensitivity to methacholine (MCh). However, many individuals with chronic cough who are being evaluated for possible cough variant asthma have normal airway sensitivity, yet cough during MCh challenge test (termed COUGH). Despite normal airway sensitivity, individuals with COUGH develop small airway obstruction, dynamic hyperinflation, and gas trapping. The clinical importance of COUGH remains to be determined, but it may be a distinct airway disease phenotype. Previous studies examining pathophysiological differences between classic asthma, cough variant asthma, and COUGH have concluded that differences may lie in individuals' sensitivity to MCh and the degree of bronchodilation and bronchoprotection obtained from deep inspirations. These observations were made exclusively using MCh challenges; however, indirect inhalation challenges (eg, mannitol, hypertonic saline, and eucapneic voluntary hyperventilation) have greater specificity for asthma and may reveal additional pathophysiological distinctions between classic asthma, cough variant asthma, and COUGH. This review highlights opportunities to gain insight into the related airway phenotypes of classic asthma, cough variant asthma, and COUGH by examining impulse oscillometry measurements and the degree of bronchodilation and bronchoprotection from deep inspirations using indirect inhalation challenges, including eucapneic voluntary hyperventilation, hypertonic saline, and mannitol.

Background: Up to 70% of patients near the end of their lives experience dyspnea, a common and upsetting symptom of advanced disease. Fan therapy is a straightforward nonpharmacologic intervention that may provide symptom relief, although trial results have been mixed. To address this uncertainty, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs), including both parallel-group and crossover designs, evaluating face-directed fan therapy in adults with advanced disease, such as advanced cancer, COPD, interstitial lung disease, or heart failure.

Methods: We searched PubMed, Embase, and Cochrane CENTRAL from inception to August 2025 for RCTs evaluating face-directed fan therapy in adults with advanced disease. Eligible comparators included sham interventions, usual care, or no intervention. Primary outcome was change in dyspnea severity scores; secondary outcomes included breathing frequency and oxygen saturation. Random-effects meta-analysis was used to calculate standardized mean differences (SMDs) with 95% CIs.

Results: Twelve RCTs with 463 subjects were included. Fan therapy significantly reduced immediate dyspnea compared with control (SMD = -1.33, 95% CI -2.12 to -0.53, P = .001), although heterogeneity was high (I² = 91%). No statistically significant benefit was observed for cumulative short-term dyspnea (SMD = -0.10, 95% CI -0.41 to 0.21, P = .53), breathing frequency (SMD = -0.73, 95% CI -1.81 to 0.36, P = .19), or oxygen saturation (SMD = 0.44, 95% CI -0.21 to 1.08, P = .19).

Conclusions: In subjects with advanced disease, fan therapy is a safe, affordable, and well-tolerated intervention that quickly relieves dyspnea, especially in supportive and palliative care settings. Larger, multi-center RCTs with standardized outcomes are necessary to elucidate sustained effects, as its long-term benefits are still unclear.

Background: Congenital heart disease (CHD) is a leading contributor to pediatric morbidity and mortality worldwide. Postoperative respiratory complications, particularly reintubation, remain a critical concern following cardiac surgery in children. This study evaluates the effectiveness of early nasal CPAP in reducing reintubation rates and respiratory complications in children with CHD after extubation.

Methods: A single-center randomized controlled trial was conducted from July 2022 to July 2024. A total of 264 children (≤3 years) undergoing cardiac surgery for CHD were randomized to either an intervention group (n = 132), receiving nasal CPAP (4 cm H₂O pressure, 5 L/min oxygen flow) immediately postextubation, or a control group (n = 132), receiving standard nasal cannula oxygen therapy. The primary outcome was reintubation within 48 h. Secondary outcomes included ventilation parameters (PaO₂, P_aCO2, S_pO2) and respiratory complications (eg, bronchospasm, hypoxemia).

Results: The reintubation rate within 48 h was significantly lower in the CPAP group compared with the control group (12% vs 28%, risk ratio 0.41, 95% CI 0.22-0.76, P < .05). The CPAP group demonstrated marked improvements in ventilation parameters (PaO₂, P_aCO2, S_pO2) at 4, 8, and 12 h postextubation (P < .05 for all). Additionally, the incidence of respiratory complications was notably reduced in the intervention group (P < .05).

Conclusions: Early application of nasal CPAP postextubation significantly reduces reintubation rates and enhances respiratory outcomes in children with CHD. This low-complexity CPAP shows promise for adoption in resource-limited settings, with potential cost advantages meriting further investigation.

Background: A number of circuit configurations can be proposed for implementing mechanical ventilation, most of which are likely to impact the instrumental dead space and thus, on alveolar ventilation. This bench study was designed to investigate the effects of circuit configuration on $P_{{\mathrm{CO}}_2}$ with constant ventilator settings (iso-V_T condition; V_T: tidal volume) and to evaluate the modifications of V_T required to maintain stable alveolar ventilation with each circuit configuration (iso-$P_{\mathrm{ET}{\mathrm{CO}}_2}$ condition; end-tidal CO₂ partial pressure being considered as a surrogate for alveolar ventilation).

Methods: A total of 17 configurations were evaluated, including valve and leak circuits, heater humidifier or different heat and moisture exchangers, with or without catheter mount, and both invasive and noninvasive situations. All these evaluations were performed at 2 different respiratory rate, both in iso-V_T and iso-$P_{\mathrm{ET}{\mathrm{CO}}_2}$ conditions.

Results: With valve circuits, modifications of instrumental dead space resulted in $P_{\mathrm{ET}{\mathrm{CO}}_2}$ variations reaching up to 16 mm Hg from one configuration to another. The corresponding increase in the required V_T to compensate for the additional dead space reached up to 120 mL. Leak circuits significantly reduced the effects of instrumental dead space compared with valve circuits.

Conclusions: Any modification of the circuit configuration requires a systematic reevaluation of ventilation efficiency.

Background: Critical bronchiolitis is a common reason for pediatric intensive care unit (PICU) admission, and management varies widely, with limited data from South American PICUs. This study aimed to characterize critical bronchiolitis trajectories in a Brazilian PICU and to measure adherence to a clinical protocol deemphasizing ancillary pharmacologic treatments while using the modified Wood-Downes score (mWDS) to guide respiratory support. It also aimed to assess whether admission mWDS would be associated with the need for subsequent invasive mechanical ventilation.

Methods: We conducted a retrospective cohort study of infants <24 months admitted with critical bronchiolitis to a Brazilian PICU between March 2021 and April 2023. The protocol was implemented in January 2021 and discouraged the use of inhaled β-agonists, systemic corticosteroids, and inhaled hypertonic saline. It also recommended respiratory support based on the mWDS conventional oxygen for scores ≤3, high-flow nasal cannula (HFNC) or noninvasive ventilation (NIV) for scores 4-7, and consideration of mechanical ventilation for scores >7. We assessed patient characteristics, protocol adherence, and predictive value of admission mWDS for intubation.

Results: Among 299 infants (median age 4.9 mo), 69% had respiratory syncytial virus infection. Maximum respiratory support was conventional oxygen in 61%, HFNC in 22%, NIV in 14%, and mechanical ventilation in 3%. Complete protocol adherence was 43%. Individual component adherence varied: hypertonic saline 100%, corticosteroids 83%, β-agonists 77%, and appropriate respiratory support 54%. Most protocol violations (66%) involved undertreatment with conventional oxygen for mWDS 4-7. The mWDS score at PICU admission was associated with intubation with an area under the curve of 0.77 (95% CI: 0.63-0.91); no subject with mWDS at PICU admission <4 required intubation.

Conclusions: This Brazilian cohort demonstrated low intubation rates despite suboptimal protocol adherence. The mWDS score at PICU admission showed acceptable discrimination for the need for mechanical ventilation, with scores <4 identifying low-risk patients.

Background: Electrical impedance tomography (EIT) is a noninvasive method for visualization and quantification of regional ventilation. The objective of this study was to assess regional variations in ventilation across different positions in healthy subjects.

Methods: Regional differences in ventilation were compared between the right and left lateral decubitus positions, as well as between the supine, semi-sitting, and prone positions. EIT was performed using a PulmoVista 500 (Dräger Medical, Lübeck, Germany).

Results: During lateral decubitus, ventilation significantly increased in the dependent lung. In the right lung, ventilation was 42.5 ± 11.4% in the left lateral decubitus compared with 65.2 ± 12.8% in the right lateral decubitus (P < .001). In the left lung, ventilation was 56.6 ± 11.6% in left lateral decubitus versus 34.4 ± 13.0% in right lateral decubitus (P < .001). These changes were mainly observed in the ventral dependent quadrants. In the supine, semi-sitting, and prone positions, no global differences in ventilation distribution were observed. However, ventilation slightly increased in the left ventral quadrant (supine < prone, P = .03) and decreased in the right dorsal quadrant (supine > prone, P = .03). These subtle variations likely reflect the physiological characteristics of healthy individuals.

Conclusions: EIT demonstrated a clear redistribution of ventilation toward the dependent lung in lateral decubitus positions. In contrast, only minimal regional ventilation changes were observed among supine, semi-sitting, and prone positions in healthy subjects. These findings support the utility of EIT in assessing position-related ventilation shifts and underscore the need for further research in patients with impaired pulmonary function.

Fragmented care models for sleep medicine in Canada disadvantage individuals with socioeconomic barriers. This can lead to delays in diagnoses, treatment, and increased health care utilization.

Background: Fragmented care models for sleep medicine in Canada disadvantages individuals with socioeconomic barriers. This can lead to delays in diagnoses, treatment, and increased health care utilization. This study aimed to explore whether subjects who receive polysomnography (PSG) during hospitalization represent a marginalised population.

Methods: We identified subjects who underwent PSG during hospitalization (inpatient PSG) at an academic hospital in Canada, from January 1, 2019, to December 31, 2021. Time, age- and sex-matched control groups were derived in a 2:1 allocation ratio inclusive of: hospitalized individuals who did not undergo PSG (inpatient control) and individuals referred to an ambulatory sleep medicine clinic (clinic control). Comorbidities, socioeconomic deprivation and marginalization indices, rurality, and health care utilization within the preceding year to enrollment, were compared between groups.

Results: We matched 275 inpatient PSG with 550 inpatient control and 550 clinic control subjects. Compared to both control groups, the inpatient PSG group had greater burden of comorbidities and more frequent specialist physician appointments. They had greater marginalization index, social assistance use, and lower income levels compared to clinic control subjects. More frequent emergency department visits, acute care admissions, and days in hospital were observed in the inpatient PSG group compared to clinic control subjects. Inpatient PSG subjects had more severe sleep disordered breathing (SDB) compared to clinic control subjects.

Conclusions: Subjects evaluated with in-patient PSG had a greater multimorbidity, social disadvantages, and health care usage. Future prospective trials are needed to determine whether routine use of in-patient PSGs can reduce complications associated with untreated SDB.