Exploring alveolar recruitability using positive end-expiratory pressure in mice overexpressing TGF-β1: a structure-function analysis

Pre-injured lungs are prone to injury progression in response to mechanical ventilation. Heterogeneous ventilation due to (micro)atelectases imparts injurious strains on open alveoli (known as volutrauma). Hence, recruitment of (micro)atelectases by positive end-expiratory pressure (PEEP) is necessary to interrupt this vicious circle of injury but needs to be balanced against acinar overdistension. In this study, the lung-protective potential of alveolar recruitment was investigated and balanced against overdistension in pre-injured lungs. Mice, treated with empty vector (AdCl) or adenoviral active TGF-β1 (AdTGF-β1) were subjected to lung mechanical measurements during descending PEEP ventilation from 12 to 0 cmH2O. At each PEEP level, recruitability tests consisting of two recruitment maneuvers followed by repetitive forced oscillation perturbations to determine tissue elastance (H) and damping (G) were performed. Finally, lungs were fixed by vascular perfusion at end-expiratory airway opening pressures (Pao) of 20, 10, 5 and 2 cmH2O after a recruitment maneuver, and processed for design-based stereology to quantify derecruitment and distension. H and G were significantly elevated in AdTGF-β1 compared to AdCl across PEEP levels. H was minimized at PEEP = 5-8 cmH2O and increased at lower and higher PEEP in both groups. These findings correlated with increasing septal wall folding (= derecruitment) and reduced density of alveolar number and surface area (= distension), respectively. In AdTGF-β1 exposed mice, 27% of alveoli remained derecruited at Pao = 20 cmH2O. A further decrease in Pao down to 2 cmH2O showed derecruitment of an additional 1.1 million alveoli (48%), which was linked with an increase in alveolar size heterogeneity at Pao = 2-5 cmH2O. In AdCl, decreased Pao resulted in septal folding with virtually no alveolar collapse. In essence, in healthy mice alveoli do not derecruit at low PEEP ventilation. The potential of alveolar recruitability in AdTGF-β1 exposed mice is high. H is optimized at PEEP 5-8 cmH2O. Lower PEEP folds and larger PEEP stretches septa which results in higher H and is more pronounced in AdTGF-β1 than in AdCl. The increased alveolar size heterogeneity at Pao = 5 cmH2O argues for the use of PEEP = 8 cmH2O for lung protective mechanical ventilation in this animal model.

Respiratory Morbidity and Mortality of Traumatic Cervical Spinal Injury

BACKGROUND

Traumatic cervical spinal injuries can severely affect respiratory function and cause significant morbidity and mortality. The typical respiratory morbidity in cervical spine injury is Atelectasis, Ventilator-associated pneumonia, acute respiratory distress syndrome and delayed weaning, etc. The study aims to see the prevalence of respiratory morbidity as well as mortality associated with cervical spine injury.

METHODS

Cross sectional study based on retrospective data was conducted on the X Sciences with the existing hospital record during the period of 3 years to find out the prevalence respiratory morbidity like Ventilatory Associated Pneumonia, delayed weaning, ARDS, atelectasis of traumatic cervical spine injury, determine the prevalence, type, and impact of respiratory morbidity and mortality in this population.

RESULTS

Total no 76 patients data meeting the inclusion criteria included in study. Male patients were more prone to develop traumatic cervical spinal injuries (SCI). The prevalence of respiratory morbidity in term of VAP(57.89), delayed weaning(46.05) and Atelectasis(22.36) was high. Patients with Asia A Neurology has higher association for VAP and delayed weaning, while Asia E Neurology patients had no respiratory morbidity. The study found a significant positive association between respiratory morbidity with hospital stay, and ventilator days (p-value: 0.019 and 0.048). A total of 15 patients died, 28.95% were discharged on request and 40.8% leaving the hospital against medical advice.

CONCLUSIONS

The prevalence of respiratory morbidity higher in cervical spine injury. Furthermore, it has associated with prolonged ICU and ventilator days and increase in mortality.

Early respiratory interventional therapy combined with antifungal agent for endobronchial cryptococcosis: A case report and literature review

RATIONALE

Cryptococcosis presenting as endobronchial obstruction and lung collapse is an extremely rare occurrence. While these patients were treated with antifungal agents, unfortunately, half of them showed a suboptimal response.

PATIENT CONCERNS

A 45-year-old immunocompetent male was admitted to the hospital due to a cough, yellow phlegm, and dyspnea persisting for 5 months. Chest computer tomography revealed a mass in the right main bronchus accompanied by right lower lobe atelectasis.

DIAGNOSES

Endobronchial cryptococcosis presenting as endobronchial obstruction and lung collapse.

INTERVENTIONS

Early rigid bronchoscopic therapy was performed to resect endobronchial obstruction, which combined with antifungal agent.

OUTCOMES

The patient recovered well with completely clinical and radiologic resolution at 1 year follow-up.

LESSONS

This case provides a good example of successful utilization of the early respiratory interventional therapy combined with antifungal agent in obstructive endobronchial cryptococcosis.

Endobronchial lesion in a premature neonate

Endobronchial and endotracheal tumours are rare in the paediatric population, especially in neonates. The common presentation is respiratory distress with persistent lung collapse or hyperinflation. Treatment usually involves endoscopic or surgical lobar resection. This case presents a preterm neonate who developed acute respiratory distress with persistent right upper lobe atelectasis. A flexible bronchoscopy showed a pediculate violaceous endobronchial lesion in the right main bronchus. Endoscopic resection was not possible due to the patient's low weight and the decision was made to support the patient with continuous positive airway pressure (CPAP) at home, while monitoring her closely. Remarkably, the lesion spontaneously resolved, and CPAP support was discontinued successfully. The case emphasises the importance of early bronchoscopy, continuous monitoring and the possibility of using CPAP support until conditions are reunited for an eventual resection. This unique case also demonstrates the potential for spontaneous resolution in some cases.

Respiratory effects of pressure support ventilation in spontaneously breathing patients under anaesthesia: Randomised controlled trial

BACKGROUND

Lung volume loss is a major risk factor for postoperative respiratory complications after general anaesthesia and mechanical ventilation. We hypothesise that spontaneous breathing without pressure support may enhance the risk for atelectasis development. Therefore, we aimed at characterising whether pressure support prevents changes in lung function in patients breathing spontaneously through laryngeal mask airway.

METHODS

In this randomised controlled trial, adult female patients scheduled for elective gynaecological surgery in lithotomy position were randomly assigned to the continuous spontaneous breathing group (CSB, n = 20) or to the pressure support ventilation group (PSV, n = 20) in a tertiary university hospital. Lung function measurements were carried out before anaesthesia and 1 h postoperatively by a researcher blinded to the group allocation. Lung clearance index calculated from end-expiratory lung volume turnovers as primary outcome variable was assessed by the multiple-breath nitrogen washout technique (MBW). Respiratory mechanics were measured by forced oscillations to assess parameters reflecting the small airway function and respiratory tissue stiffness.

RESULTS

MBW was successfully completed in 18 patients in both CSB and PSV groups. The decrease in end-expiratory lung volume was more pronounced in the CSB than that in the PSV group (16.6 ± 6.6 [95% CI] % vs. 7.6 ± 11.1%, p = .0259), with no significant difference in the relative changes of the lung clearance index (-0.035 ± 7.1% vs. -0.18 ± 6.6%, p = .963). The postoperative changes in small airway function and respiratory tissue stiffness were significantly lower in the PSV than in the CSB group (p < .05 for both).

CONCLUSIONS

These results suggest that pressure support ventilation protects against postoperative lung-volume loss without affecting ventilation inhomogeneity in spontaneously breathing patients with increased risk for atelectasis development.

TRIAL REGISTRATION

NCT02986269.

Effect of an Individualized Lung Protective Ventilation on Lung Strain and Stress in Children Undergoing Laparoscopy: An Observational Cohort Study

BACKGROUND

Exaggerated lung strain and stress could damage lungs in anesthetized children. The authors hypothesized that the association of capnoperitoneum and lung collapse in anesthetized children increases lung strain-stress. Their primary aim was to describe the impact of capnoperitoneum on lung strain-stress and the effects of an individualized protective ventilation during laparoscopic surgery in children.

METHODS

The authors performed an observational cohort study in healthy children aged 3 to 7 yr scheduled for laparoscopic surgery in a community hospital. All received standard protective ventilation with 5 cm H2O of positive end-expiratory pressure (PEEP). Children were evaluated before capnoperitoneum, during capnoperitoneum before and after lung recruitment and optimized PEEP (PEEP adjusted to get end-expiratory transpulmonary pressure of 0), and after capnoperitoneum with optimized PEEP. The presence of lung collapse was evaluated by lung ultrasound, positive Air-Test (oxygen saturation measured by pulse oximetry 96% or less breathing 21% O2 for 5 min), and negative end-expiratory transpulmonary pressure. Lung strain was calculated as tidal volume/end-expiratory lung volume measured by capnodynamics, and lung stress as the end-inspiratory transpulmonary pressure.

RESULTS

The authors studied 20 children. Before capnoperitoneum, mean lung strain was 0.20 ± 0.07 (95% CI, 0.17 to 0.23), and stress was 5.68 ± 2.83 (95% CI, 4.44 to 6.92) cm H2O. During capnoperitoneum, 18 patients presented lung collapse and strain (0.29 ± 0.13; 95% CI, 0.23 to 0.35; P < 0.001) and stress (5.92 ± 3.18; 95% CI, 4.53 to 7.31 cm H2O; P = 0.374) increased compared to before capnoperitoneum. During capnoperitoneum and optimized PEEP, children presenting lung collapse were recruited and optimized PEEP was 8.3 ± 2.2 (95% CI, 7.3 to 9.3) cm H2O. Strain returned to values before capnoperitoneum (0.20 ± 0.07; 95% CI, 0.17 to 0.22; P = 0.318), but lung stress increased (7.29 ± 2.67; 95% CI, 6.12 to 8.46 cm H2O; P = 0.020). After capnoperitoneum, strain decreased (0.18 ± 0.04; 95% CI, 0.16 to 0.20; P = 0.090), but stress remained higher (7.25 ± 3.01; 95% CI, 5.92 to 8.57 cm H2O; P = 0.024) compared to before capnoperitoneum.

CONCLUSIONS

Capnoperitoneum increased lung strain in healthy children undergoing laparoscopy. Lung recruitment and optimized PEEP during capnoperitoneum decreased lung strain but slightly increased lung stress. This little rise in pulmonary stress was maintained within safe, lung-protective, and clinically acceptable limits.

EDITOR’S PERSPECTIVE

Facilitating Lung Collapse for Thoracoscopic Surgery Utilizing Endobronchial Airway Occlusion Preceded by Pleurotomy and One-minute Suspension of Two-lung Ventilation

OBJECTIVES

To assess when and whether clamping the double-lumen endobronchial tube (DLT) limb of the non-ventilated lung is more conducive to a rapid and effective lung deflation than simply allowing the open limb of the DLT to communicate with the atmosphere.

DESIGN

This was a single-center, single-blind, randomized, controlled trial.

SETTING

The trial was performed in a single institutional setting.

PARTICIPANTS

The participants were 60 patients undergoing elective video-assisted thoracoscopic surgery.

INTERVENTIONS

Patients were randomized to the open-clamp airway technique (OCAT group) or control group. Patients in the control group had one-lung ventilation initiated upon being placed in the lateral decubitus position. The OCAT group had two-lung ventilation maintained until the pleural cavity was opened with the introduction of a planned thoracoscopic access port to allow the operated lung to fall away from the chest wall. Thereafter, ventilation was suspended (temporarily ceased) for 1 minute before the DLT lumen of the isolated lung was clamped. The primary outcome of the trial was the time to complete lung collapse scored as determined from video clips taken during surgery. The secondary outcomes were (1) lung collapse score at 30 minutes after pleural incision, (2) surgeon satisfaction with surgery, and (3) intraoperative hypoxemia.

MEASUREMENTS AND MAIN RESULTS

The median time to reach complete lung collapse in the OCAT group was 10 minutes (odds ratio 10.0, 95% CI 6.3-13.7), which was much shorter than that of the control group (25 minutes [odds ratio 25.0, 95% CI 13.6-36.4]). The difference in complete lung collapse at 30 minutes between the 2 groups was significant (p < 0.001). The surgeon's satisfaction with surgery was higher in the OCAT group than in the control group (8.5 ± 0.2 vs 6.8 ± 0.2; p < 0.001). There was no difference regarding intraoperative hypoxemia.

CONCLUSIONS

Suspending ventilation of both DLT limbs for 1 minute after pleural cavity opening and then clamping the DLT lumen of the isolated lung resulted in a more rapid deflation of the surgical lung. This open-clamp airway technique is an effective technique for rapid surgical lung collapse during thoracoscopic surgery.

Causes of Hypoxemia in COVID-19 Acute Respiratory Distress Syndrome: A Combined Multiple Inert Gas Elimination Technique and Dual-energy Computed Tomography Study

BACKGROUND

Despite the fervent scientific effort, a state-of-the art assessment of the different causes of hypoxemia (shunt, ventilation-perfusion mismatch, and diffusion limitation) in COVID-19 acute respiratory distress syndrome (ARDS) is currently lacking. In this study, the authors hypothesized a multifactorial genesis of hypoxemia and aimed to measure the relative contribution of each of the different mechanism and their relationship with the distribution of tissue and blood within the lung.

METHODS

In this cross-sectional study, the authors prospectively enrolled 10 patients with COVID-19 ARDS who had been intubated for less than 7 days. The multiple inert gas elimination technique (MIGET) and a dual-energy computed tomography (DECT) were performed and quantitatively analyzed for both tissue and blood volume. Variables related to the respiratory mechanics and invasive hemodynamics (PiCCO [Getinge, Sweden]) were also recorded.

RESULTS

The sample (51 ± 15 yr; Pao2/Fio2, 172 ± 86 mmHg) had a mortality of 50%. The MIGET showed a shunt of 25 ± 16% and a dead space of 53 ± 11%. Ventilation and perfusion were mismatched (LogSD, Q, 0.86 ± 0.33). Unexpectedly, evidence of diffusion limitation or postpulmonary shunting was also found. In the well aerated regions, the blood volume was in excess compared to the tissue, while the opposite happened in the atelectasis. Shunt was proportional to the blood volume of the atelectasis (R2 = 0.70, P = 0.003). V˙A/Q˙T mismatch was correlated with the blood volume of the poorly aerated tissue (R2 = 0.54, P = 0.016). The overperfusion coefficient was related to Pao2/Fio2 (R2 = 0.66, P = 0.002), excess tissue mass (R2 = 0.84, P < 0.001), and Etco2/Paco2 (R2 = 0.63, P = 0.004).

CONCLUSIONS

These data support the hypothesis of a highly multifactorial genesis of hypoxemia. Moreover, recent evidence from post-mortem studies (i.e., opening of intrapulmonary bronchopulmonary anastomosis) may explain the findings regarding the postpulmonary shunting. The hyperperfusion might be related to the disease severity.

EDITOR’S PERSPECTIVE

Effect of sugammadex on postoperative complications in patients with severe burn who underwent surgery: a retrospective study

This retrospective study investigated the association of sugammadex with postoperative pulmonary complication risk between 2013 and 2021 in patients with severe burn of five hospitals. Postoperative pulmonary complications included atelectasis, pulmonary edema, pulmonary effusion, pneumothorax, pneumonia, pulmonary thromboembolism, respiratory failure and acute respiratory distress. To identify whether sugammadex reduced the risk of postoperative pulmonary complication in patients with severe burn who underwent surgery, Kaplan-Meier curve were used to check the difference of incidence according to surgical cases and time-varying Cox hazard regression were used to calculate the hazard ratio. The study included 1213 patients with severe burn who underwent 2259 surgeries. Postoperative pulmonary complications were occurred in 313 (25.8%) patients. Among 2259 surgeries, sugammadex was used in 649 (28.7%) surgeries. Cumulative postoperative pulmonary complication were 268 (16.6%) cases in surgeries without sugammadex, and 45 (6.9%) cases in surgeries with sugammadex, respectively (P < 0.005). The postoperative pulmonary complications risk was reduced significantly in patients who use sugammadex than those who did not use sugammadex. (Adjusted hazard ratio, 0.61; 95% confidence interval, 0.42-0.89; P = 0.011). In conclusion, sugammadex reduced risk of postoperative pulmonary complications compared with nonuse of sugammadex in patients with severe burn who underwent surgery.

The SPEC score-A quantifiable CT scoring system for primary ciliary dyskinesia

BACKGROUND

Structural lung changes seen on computed tomography (CT) scans in persons with primary ciliary dyskinesia (pwPCD) are currently described using cystic fibrosis (CF) derived scoring systems. Recent work has shown structural changes and frequencies that are unique to PCD, indicating the need for a unique PCD-derived scoring system.

METHODS

Chest CT scans from 30 pwPCD, were described for structural changes including bronchiectasis, bronchial wall thickening, mucous plugging, atelectasis, air trapping, and interlobar septal thickening and, additionally, changes previously described as being frequent in pwPCD including extensive tree-in-bud pattern of mucous plugging, bronchoceles or nodules, thickening of interlobar and interlobular septa and whole lobe atelectasis. Based on these findings a novel and unique scoring system, the Specific PCD Evaluation by CT (SPEC) score was constructed. Scans were then re-scored using the SPEC score and results compared to corresponding measurements of lung function to assess structure-function correlation.

RESULTS

Total SPEC scores ranged from 0 to 60 (max possible score 90). There was a strong negative correlation between the SPEC score (SPEC) and forced vital capacity (FVC), forced expiratory volume over 1 s (FEV1 ) and FEV1 /FVC ratio (-r = .784, -.865, -.872 respectively).

CONCLUSIONS

Using PCD-derived data we describe the construct of a PCD-specific score for assessing lung structural damage on CT scans, the SPEC score. A strong correlation between the SPEC score and PFT variables was identified. The SPEC score holds the potential for describing longitudinal changes in CT scans and assessing the efficacy of interventive therapies in patients with PCD.

One-lung ventilation with a bronchial blocker in thoracic patients

BACKGROUND

Lung isolation is a technique used in a multitude of surgeries to ensure single-lung ventilation with collapse of the contralateral lung, as to achieve improved access and visualization of relevant anatomical structures. Despite being accepted and having favorable outcomes, bronchial blockers (BBs) are not to this day the main device of choice among anaesthesiologists.

METHODS

In this retrospective and descriptive study, we analyzed the safety and efficacy of a BB in all types of thoracic surgeries in our centre between 2015 and 2022, excluding patients with massive hemoptysis or empyema, or who had undergone a prior pneumonectomy.

RESULTS

One hundred and thirty-four patients were intervened due to lung cancer (67.9%), respiratory disease (23.9%), and non-respiratory disease (8.2%) undergoing lung surgeries (65.7%), pleural and mediastinal surgeries (29.9%), chest wall surgeries (3.0%) and other surgeries (1.5%). In most cases, lung collapse was considered excellent (63.9%) or good (33.1%) with only 4 cases (3.0%) of poor lung collapse. More than 90% of patients did not present intraoperative or immediate postoperative complications. No statistically significant differences were found between lung collapse and the demographic, clinical or BB-related variables (p > 0.05). However, we found a significatively higher proportion of excellent lung collapses in VATS surgeries and lateral decubitus positioning, as well as a significatively less proportion of poor lung collapses (p < 0.05). Moreover, there was a significantly higher proportion of excellent lung collapses when the BB was placed in the left bronchus (p < 0.05).

CONCLUSIONS

With these results, in our experience BBs constitute an effective alternative, capable of achieving pulmonary collapse in all kinds of thoracic procedures with satisfactory safety rates due to their minimal complications.

Effects of laryngeal mask ventilation on postoperative atelectasis in children undergoing day surgery: a randomized controlled trial

BACKGROUND

To compare the effects of laryngeal mask mechanical ventilation and preserved spontaneous breathing on postoperative atelectasis in children undergoing day surgery.

METHODS

Children aged 3-7 who underwent elective day surgery were randomly divided into a spontaneous breathing group (n = 23) and a mechanical ventilation group (n = 23). All children enrolled in this trial used the same anesthesia induction protocol, the incidence and severity of atelectasis before induction and after operation were collected. In addition, the baseline data, intraoperative vital signs, ventilator parameters and whether there were complications such as reflux and aspiration were also collected. SPSS was used to calculate whether there was a statistical difference between these indicators.

RESULTS

The incidence of atelectasis in the spontaneous breathing group was 91.30%, and 39.13% in the mechanical ventilation group, and the difference was statistically significant (P = 0.001). There was a statistically significant difference in carbon dioxide (P < 0.05), and the severity of postoperative atelectasis in the mechanical ventilation group was lower than that in the spontaneous breathing group (P < 0.05). In addition, there were no significant differences in the vital signs and baseline data of the patients (P > 0.05).

CONCLUSION

Laryngeal mask mechanical ventilation can reduce the incidence and severity of postoperative atelectasis in children undergoing day surgery, and we didn't encounter any complications such as reflux and aspiration in children during the perioperative period, so mechanical ventilation was recommended to be used for airway management.

TRIAL REGISTRATION

The clinical trial was registered retrospectively at the Chinese Clinical Trial Registry. ( https://www.chictr.org.cn . Registration number ChiCTR2300071396, Weiwei Cai, 15 May 2023).

Bronchoscopy for management and identification of etiology of right middle lobe syndrome: Analysis of 66 cases

BACKGROUND

Right middle lobe (RML) syndrome is a recurrent or chronic obstruction of the RML causing atelectasis of the right middle lobe due to mechanical and nonmechanical etiologies. The consequences of untreated RML syndrome range from chronic cough to post-obstructive pneumonia and bronchiectasis. We report here our bronchoscopy experience in patients with RML syndrome.

METHODS

We conducted a retrospective study of adult patients who underwent bronchoscopy for RML syndrome at Rabin Medical Center from 2008 through 2022. Demographic data and medical history, bronchoscopy findings and procedures, and follow-up results were collected.

RESULTS

A total of 66 patients (57.6% male, mean age 63 ± 13 years) underwent bronchoscopy for RML syndrome during the study period. Bronchoscopy revealed a mechanical etiology in 49 (74.2%) cases, including endobronchial mass (21, 31.8%) and external compression (7, 10.6%). Malignancy was identified in 20 (30.3%) cases. In 62 patients (93.9%), the bronchoscopy resulted in partial or complete reopening of the RML bronchus. The therapeutic bronchoscopic procedures were balloon dilatation (19), laser ablation (17), mechanical debridement (12), endobronchial stent insertion (11), and cryoablation (6).

CONCLUSIONS

Malignancy was identified as the etiology of RML syndrome in approximately 25% of cases, suggesting bronchoscopy should be performed in every case of RML atelectasis. To our knowledge, this is the first reported series of endobronchial stenting of the RML bronchus in the context of RML syndrome.

Effects of atelectatic areas on the surrounding lung tissue during mechanical ventilation in an experimental model of acute lung injury induced by lipopolysaccharide

OBJECTIVE

To assess the effect of atelectasis during mechanical ventilation on the periatelectatic and normal lung regions in a model of atelectasis in rats with acute lung injury induced by lipopolysaccharide.

METHODS

Twenty-four rats were randomized into the following four groups, each with 6 animals: the Saline-Control Group, Lipopolysaccharide Control Group, Saline-Atelectasis Group, and Lipopolysaccharide Atelectasis Group. Acute lung injury was induced by intraperitoneal injection of lipopolysaccharide. After 24 hours, atelectasis was induced by bronchial blocking. The animals underwent mechanical ventilation for two hours with protective parameters, and respiratory mechanics were monitored during this period. Thereafter, histologic analyses of two regions of interest, periatelectatic areas and the normally-aerated lung contralateral to the atelectatic areas, were performed.

RESULTS

The lung injury score was significantly higher in the Lipopolysaccharide Control Group (0.41 ± 0.13) than in the Saline Control Group (0.15 ± 0.51), p < 0.05. Periatelectatic regions showed higher lung injury scores than normally-aerated regions in both the Saline-Atelectasis (0.44 ± 0.06 x 0.27 ± 0.74 p < 0.05) and Lipopolysaccharide Atelectasis (0.56 ± 0.09 x 0.35 ± 0.04 p < 0.05) Groups. The lung injury score in the periatelectatic regions was higher in the Lipopolysaccharide Atelectasis Group (0.56 ± 0.09) than in the periatelectatic region of the Saline-Atelectasis Group (0.44 ± 0.06), p < 0.05.

CONCLUSION

Atelectasis may cause injury to the surrounding tissue after a period of mechanical ventilation with protective parameters. Its effect was more significant in previously injured lungs.

Effect of a pre-emptive 2-hour session of high-flow nasal oxygen on postoperative oxygenation after major gynaecologic surgery: a randomised clinical trial

BACKGROUND

We aimed at determining whether a 2-h session of high-flow nasal oxygen (HFNO) immediately after extubation improves oxygen exchange after major gynaecological surgery in the Trendelenburg position in adult female patients.

METHODS

In this single-centre, open-label, randomised trial, patients who underwent major gynaecological surgery were randomised to HFNO or conventional oxygen treatment with a Venturi mask. The primary outcome was the Pao2/FiO2 ratio after 2 h of treatment. Secondary outcomes included lung ultrasound score, diaphragm thickening fraction, dyspnoea, ventilatory frequency, Paco2, the percentage of patients with impaired gas exchange (Pao2/FiO2 ≤40 kPa) after 2 h of treatment, and postoperative pulmonary complications at 30 days.

RESULTS

A total of 83 patients were included (42 in the HFNO group and 41 in the conventional treatment group). After 2 h of treatment, median (inter-quartile range) Pao2/FiO2 was 52.9 (47.9-65.2) kPa in the HFNO group and 45.7 (36.4 -55.9) kPa in the conventional treatment group (mean difference 8.7 kPa [95% CI: 3.4 to 13.9], P=0.003). The lung ultrasound score was lower in the HFNO group than in the conventional treatment group (9 [6-10] vs 12 [10-14], P<0.001), mostly because of the difference of the score in dorsal areas (7 [6-8] vs 10 [9-10], P<0.001). The percentage of patients with impaired gas exchange was lower in the HFNO group than in the conventional treatment group (5% vs 37%, P<0.001). All other secondary outcomes were not different between groups.

CONCLUSIONS

In patients who underwent major gynaecological surgery, a pre-emptive 2-h session of HFNO after extubation improved postoperative oxygen exchange and reduced atelectasis compared with a conventional oxygen treatment strategy.

CLINICAL TRIAL REGISTRATION

NCT04566419.

Postoperative pulmonary complications in patients undergoing aortic surgery: A single-center retrospective study

Postoperative pulmonary complications (PPCs) are among the most common complications after cardiovascular surgery. This study aimed to explore the real incidence of and risk factors for PPC in patients with acute type A aortic dissection (ATAAD) who underwent total aortic arch replacement combined with the frozen elephant trunk (TAR + FET). In total, 305 ATAAD patients undergoing TAR + FET from January 2021 to August 2022 in a single-center were divided into PPCs or non-PPCs group. The incidence of PPCs was calculated, risk factors of PPCs were analyzed, and postoperative outcomes were compared between these 2 groups. The incidence of any PPC was 29.2%. And the incidence of respiratory infection, respiratory failure, pleural effusion, atelectasis, pneumothorax, acute respiratory distress syndrome, aspiration pneumonitis, pulmonary edema and bronchospasm was 23.0%, 12.5%, 10.5%, 1.0%, 0.7%, 1.0%, 0%, 0.7%, 0%, respectively. The logistic regression analysis revealed that the history of diabetes, history of renal dysfunction, preoperative SpO2 <90%, cardiopulmonary bypass duration, fresh frozen plasma volume and platelet concentrates volume were independent risk factors for PPCs. Among 2 groups, postoperative ventilation duration, postoperative length of stay in intensive care unit and hospital were (73.5 ± 79.0 vs 24.8 ± 35.2 hours; P < .001), (228.3 ± 151.2 vs 95.2 ± 72.0 hours; P < .001) and (17.9 ± 8.8 vs 11.5 ± 6.2 days; P < .001). There was no difference between 2 groups of in-hospital mortality rate. Additionally, other short-term outcomes were also significantly poorer in patients with PPCs. PPCs are common in ATAAD patients undergoing TAR + FET, and could be multifactorial. PPCs occurrence are associated with poor patient outcomes postoperatively and worth further investigation.

[Characteristics of SPECT/CT-derived pulmonary perfusion imaging in chronic pulmonary vascular stenosis with different etiologies]

Objective: To explore the characteristics of pulmonary blood flow perfusion imaging of single photo emission computer tomography/computer tomography (SPECT/CT) in chronic pulmonary vascular Stenosis (CPVS) caused by different etiological factors. Methods: This is a retropective study. Present study screened 50 consecutive cases diagnosed with chronic pulmonary vascular stenosis from January 2019 to January 2020 in the department of cardiology of Gansu Provincial Hospital and underwent SPECT/CT pulmonary blood flow perfusion examination. Thirteen patients were excluded because of pulmonary vascular lesions with a disease course of less than 3 months and poor image quality. According to the etiology, patients were divided into fibrosing mediastinitis (FM) group, Takyasu's arteritis (PTA) group, and chronic thromboembolic pulmonary hypertension/chronic thromboembolic pulmonary disease (CTEPH/CTED) group. The severity of pulmonary blood flow perfusion was evaluated in accordance with the Begic scoring principle in the three groups. The overall Begic score, lung lobe scores among three groups were compared. CT signs of lung SPECT/CT, such as enlargement of hilar lymph node, atelectasis, bronchial stenosis, were also analyzed in three groups. Results: A total of 37 patients with chronic pulmonary vascular stenosis were finally enrolled (18 in the FM group, 5 in the PTA group, and 14 in the CTEPH/CTED group). The total Begic score of pulmonary perfusions was similar among the three groups (F=0.657,P>0.05). There was a statistically significant difference in the left upper lobe Begic score among the three groups (H=4.081, P<0.05). The left upper lobe Begic score was higher in the FM group than in the PTA group (3.44±2.50 vs. 1.60±0.55, P<0.05). As compared to other two groups, patients in FM group were featured with CT signs of higher percent of hilar enlargement (FM group vs. PTA group: 16/18 vs. 1/5, P=0.008; FM group vs. CTEPH/CTED group: 16/18 vs. 3/14, P=0.000 2), enlargement of the pulmonary hilum lymph nodes (FM group vs. PTA group: 14/18 vs. 1/5, P=0.033; FM group vs. CTEPH/CTED group: 14/18 vs. 2/14, P=0.001), and calcification of mediastinal soft tissue (FM group vs. PTA group: 11/18 to 0/5, P=0.037; FM group vs. CTEPH/CTED group: 11/18 vs. 1/14, P=0.003). The proportion of CT signs of bronchial stenosis (9/18 vs. 0/14, P=0.002) and atelectasis (9/18 vs. 1/14, P=0.002) was also higher in the FM group than in the CTEPH/CTED group. In case of abnormal pulmonary blood flow perfusion, the diagnostic accuracy of CT signs hilar enlargement, hilar lymph node enlargement, mediastinal soft tissue calcification, bronchial stenosis, and atelectasis for the diagnosis of FM were 81.1%, 83.8%, 78.4%, 75.7%, and 73.0%, respectively. Conclusion: There is no significant difference in the Begic score of SPECT/CT pulmonary blood flow perfusion imagines among the three groups of patients. Impaired pulmonary blood flow perfusion combined with typical CT signs is useful for identifying patients with FM.

Congenital myopathy presenting as recurrent pneumonia with lung collapse and pulmonary artery hypertension

A boy presented with cough, breathlessness for 1 month, fever for 1 week with similar previous episodes without hospitalisation. He had generalised muscle wasting, acute chronic malnutrition and required immediate ventilation. Provisional diagnosis of recurrent pneumonia with failure to thrive was made. As serial chest X-rays showed recurrent lung collapse, congenital lung anomalies were ruled out. 2D-echocardiography showed pulmonary arterial hypertension. Workup for congenital immunodeficiency and cystic fibrosis was negative. There was no improvement in muscle mass despite total parenteral nutrition. He was noticed to have myopathic facies. History was reviewed when the mother reported reduced fetal movements in this pregnancy. The patient had low voice amplitude. Creatine kinase levels were normal. Muscle biopsy followed by whole exome sequencing identified frameshift duplication NM_020451.3(SELENON):c.249_250dupGG (p.Asp84Glyfs*17), thus, confirming diagnosis of SEPN1-related congenital myopathy (CM) with fibre-type disproportion. Respiratory system involvement was distracter, emphasising consideration of CM while evaluating persistent lung collapse with muscle wasting.

Automatic and efficient pneumothorax segmentation from CT images using EFA-Net with feature alignment function

Pneumothorax is a condition involving a collapsed lung, which requires accurate segmentation of computed tomography (CT) images for effective clinical decision-making. Numerous convolutional neural network-based methods for medical image segmentation have been proposed, but they often struggle to balance model complexity with performance. To address this, we introduce the Efficient Feature Alignment Network (EFA-Net), a novel medical image segmentation network designed specifically for pneumothorax CT segmentation. EFA-Net uses EfficientNet as an encoder to extract features and a Feature Alignment (FA) module as a decoder to align features in both the spatial and channel dimensions. This design allows EFA-Net to achieve superior segmentation performance with reduced model complexity. In our dataset, our method outperforms various state-of-the-art methods in terms of accuracy and efficiency, achieving a Dice coefficient of 90.03%, an Intersection over Union (IOU) of 81.80%, and a sensitivity of 88.94%. Notably, EFA-Net has significantly lower FLOPs (1.549G) and parameters (0.432M), offering better robustness and facilitating easier deployment. Future work will explore the integration of downstream applications to enhance EFA-Net's utility for clinicians and patients in real-world diagnostic scenarios. The source code of EFA-Net is available at: https://github.com/tianjiamutangchun/EFA-Net .

Recommendations and considerations for speeding the collapse of the non-ventilated lung during single-lung ventilation in thoracoscopic surgery: a literature review

Video-assisted thoracoscopic thoracic surgery has the advantages of less physical damage, less postoperative pain, and a rapid recovery. Therefore, it is widely used in the clinic. The quality of nonventilated lung collapse is the key point of thoracoscopic surgery. Poor lung collapse on the operative side damages surgical exposure and prolongs the process of surgery. Therefore, it is important to achieve good lung collapse as soon as possible after opening the pleura. Over the past two decades, there have been reports of advances in research on the physiological mechanism of lung collapse and several kinds of techniques for speeding up lung collapse. This review will inform the advances of each technique, make recommendations for reasonable implementation and discuss their controversies and considerations.

Left-Sided Double-Lumen Tube vs EZ-Blocker for One-Lung Ventilation in Thoracic Surgery: A Systematic Review and Meta-Analysis

Background. The EZ-Blocker is the newest generation of bronchial blocker and offers a potential alternative to left-sided double lumen tubes for lung isolation and one-lung ventilation during thoracic surgery. Methods. Databases were searched for randomized controlled trials comparing left-sided double lumen tube to the EZ-Blocker for one-lung ventilation during thoracic surgery. The time for placement, incidence of intraoperative displacement, and surgeons' rating of lung collapse quality were designated as coprimary outcomes. The safety profiles of the two devices, including the incidence of airway trauma and post-extubation discomfort were also examined. Results. Six randomized controlled trials (495 patients) were analyzed. Compared to the EZ-Blocker, the left-sided double lumen tube was faster to place by a weighted mean difference of [95% CI] of -61.24 seconds [-102.48, -20.00] (P = .004) and was much less likely to become displaced during lung isolation with an odds ratio [95% CI] of .56 [.34, .91] (P = .02). The left-sided double lumen tube and the EZ-Blocker provided similar surgeon-rated quality of lung isolation. Although the left-sided double lumen tube caused a greater degree of post-extubation sore throat, there was a similar incidence of carinal trauma and post-extubation hoarseness compared to the EZ-Blocker. Conclusion. Our analysis suggests that the left-sided double lumen tube can be placed more quickly and is less prone to intraoperative displacement compared to the EZ-Blocker; the quality of lung collapse is similar. Thus, evidence appears to support the continued utilization of the left-sided double lumen tube for routine thoracic surgery requiring one-lung ventilation.

Sugammadex Reduced the Incidence of Postoperative Pulmonary Complications in Susceptible Patients Identified by ARISCAT Risk Index: Systematic Review and Meta-analysis

INTRODUCTION

The efficacy of sugammadex on postoperative pulmonary complications (PPCs) in susceptible patients, compared with neostigmine, remains indeterminate. The Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) Group Investigators proposed a risk index for the early identification of susceptible patients, with excellent externally validated discrimination ability. Meta-analytical techniques were applied to evaluate the efficacy of sugammadex on PPCs in patients with ARISCAT-defined risk factors.

METHODS

The study is registered on PROSPERO, number CRD42021261156. We searched PubMed, Scopus, Embase, Cochrane library, GreyNet, and OpenGrey for eligible randomized controlled trials (RCTs) without restricting the language or year of publication.

RESULTS

Twelve RCTs consisting of 1182 patients susceptible to PPCs were included. A robust reduction was observed on the incidence of PPCs in susceptible patients who received sugammadex [RR 0.66; 95% CI (0.54, 0.80), p < 0.01], with a low level of between-study heterogeneity (I2 = 45.98%; H2 = 1.85). Similar protective effects were also proved in avoiding residual neuromuscular block (NMB) [RR 0.25; 95% CI (0.11, 0.56); p < 0.01], atelectasis [RR 0.74; 95% CI (0.59, 0.95); p = 0.02], pneumonia [RR 0.49; 95% CI (0.28, 0.88); p = 0.02], and respiratory failure [RR 0.61; 95% CI (0.39, 0.96); p = 0.03]. No difference was observed regarding adverse events [RR 0.85; 95% CI (0.72, 1.01); p = 0.06].

CONCLUSION

Low to moderate quality of evidence demonstrated the edge of sugammadex over neostigmine for NMB reversal in reducing the likelihood of PPCs and residual NMB in patients with ARISCAT-defined risk factors. Clinicians may reassess the type of reversal agent when treating patients susceptible to PPCs.

Combined use of the ProSeal laryngeal mask airway and a bronchial blocker vs. a double-lumen endobronchial tube in thoracoscopic surgery: A randomized controlled trial

STUDY OBJECTIVE

The combined use of the ProSeal laryngeal mask airway and a bronchial blocker may reduce postoperative hoarseness and sore throat. We aimed to test the feasibility and efficacy of this combination technique in thoracoscopic surgery.

DESIGN

A single-center, patient-assessor blinded, randomized controlled trial.

SETTING

Nagoya City University Hospital (between November 2020 and April 2022).

PATIENTS

A total of 100 adult patients undergoing lobectomy or segmentectomy by video- or robotic-assisted thoracoscopic surgery.

INTERVENTIONS

Patients were randomly assigned to either group using a combination of the ProSeal laryngeal mask airway and a bronchial blocker (pLMA+BB group) or a double-lumen endobronchial tube (DLT group).

MEASUREMENTS

The primary outcome was the hoarseness incidence on 1-3 postoperative days. Secondary outcomes included sore throat, intraoperative complications (hypoxemia, hypercapnia, surgical interruption, malposition of devices, unintended lung expansion, and ventilatory difficulty), lung collapse, device placement-related outcomes, and coughing during emergence.

MAIN RESULTS

A total of 100 patients underwent randomization (51 to the pLMA+BB group and 49 to the DLT group). After drop outs, a total of 49 patients in each group were analyzed per-protocol. The incidences of hoarseness in the pLMA+BB and DLT groups were 42.9% and 53.1% (difference, -10.2%; 95% confidence interval, -30.1% to 10.3%; p = 0.419), 18.4% vs. 32.7%, and 20.4% vs. 24.5% on postoperative day 1, 2, and 3, respectively. The incidences of sore throat in the pLMA+BB and DLT groups were 16.3% vs. 34.7% (difference, -18.4%; 95% confidence interval, -35.9% to -0.9%; p = 0.063) on postoperative day 1. In the pLMA+BB group, more intraoperative complications and less coughing during emergence were observed compared to the DLT group. Lung collapse and placement-related outcomes were comparable between the groups.

CONCLUSIONS

The combination of ProSeal laryngeal mask airway and bronchial blocker did not significantly reduce hoarseness compared to the double-lumen endobronchial tube.

Clinical Outcomes of Bronchoscopic Cryotherapy for Central Airway Obstruction in Adults: An 11-Years' Experience of a Single Center

BACKGROUND

Although bronchoscopic cryotherapy (BC) is a pragmatic modality for recanalization of central airway obstruction (CAO), the risk of complications, such as bleeding, remains a concern. This study aimed to present the clinical outcomes of BC and evaluate the factors associated with its complications.

METHODS

In this retrospective study, we reviewed the medical records of patients who underwent BC for CAO at the Asan Medical Center, South Korea. Most sessions were conducted via flexible bronchoscopy under moderate sedation. A multivariate logistic regression analysis was used to identify the factors associated with the success rate and complications.

RESULTS

BC was performed in 262 sessions in 208 patients between January 2009 and December 2020. The most common cause of cryotherapy was recanalization of the endobronchial tumor related CAO (233/262, 88.9%). More than partial re-establishment of airway patency was achieved in 211 of 233 (90.6%) sessions. The success rate did not differ significantly in the multivariate logistic regression analysis. The most common complication was intrabronchial bleeding (78/233, 35.5%); however, severe bleeding occurred only in one case (0.4%). Univariate and multivariate logistic regression analyses revealed that diabetes mellitus (odds ratio [OR] = 2.820, P = 0.011), respiratory failure before BC (OR = 3.546, P = 0.028), and presence of distal airway atelectasis (OR = 0.417, P = 0.021) were independently associated with moderate to severe intrabronchial bleeding, while the histologic type of tumor was not related to bleeding. BC for CAO caused by blood clot or foreign body was successful in most cases, and there were no complications.

CONCLUSION

BC is an efficient and relatively safe intervention for patients with CAO. Our findings suggest that diabetes, respiratory failure before BC, and the absence of distal airway atelectasis may be risk factors of moderate to severe intrabronchial bleeding.

Case Report: Middle lobe syndrome: a rare presentation in eosinophilic granulomatosis with polyangiitis

Background

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of disorders characterized by necrotizing inflammation of small- and medium-sized blood vessels and the presence of circulating ANCA. Eosinophilic granulomatosis with polyangiitis (EGPA) is a systemic ANCA-associated vasculitis, characterized by peripheral eosinophilia, neuropathy, palpable purpuras or petechiae, renal and cardiac involvement, sinusitis, asthma, and transient pulmonary infiltrates. Middle lobe syndrome (MLS) is defined as recurrent or chronic atelectasis of the right middle lobe of the lung, and it is a potential complication of asthma.

Case presentation

Herein, we describe a case of MLS in a 51-year-old woman, never-smoker, affected by EGPA, presenting exclusively with leukocytosis and elevated concentrations of acute-phase proteins, without any respiratory symptom, cough, or hemoptysis. Chest computed tomography (CT) imaging documented complete atelectasis of the middle lobe, together with complete obstruction of lobar bronchial branch origin. Fiberoptic bronchoscopy (FOB) revealed complete stenosis of the middle lobar bronchus origin, thus confirming the diagnosis of MLS, along with distal left main bronchus stenosis. Bronchoalveolar lavage (BAL) did not detect any infection. Bronchial biopsies included plasma cells, neutrophil infiltrates, only isolated eosinophils, and no granulomas, providing the hypothesis of vasculitic acute involvement less likely. First-line agents directed towards optimizing pulmonary function (mucolytics, bronchodilators, and antibiotic course) were therefore employed. However, the patient did not respond to conservative treatment; hence, endoscopic management of airway obstruction was performed, with chest CT documenting resolution of middle lobe atelectasis.

Conclusion

To the best of our knowledge, this is the first detailed description of MLS in EGPA completely resolved through FOB. Identification of MLS in EGPA appears essential as prognosis, longitudinal management, and treatment options may differ from other pulmonary involvement in AAV patients.

Safety and feasibility of preferential manual bronchoplasty in 2-3 cm single-port video-assisted thoracoscopic lobectomy

BACKGROUND

This retrospective study aimed to compare preferential manual bronchoplasty (PMB) and mechanical stapler closure (MSC) of the bronchial stump after 2-3 cm single-port (SP) video-assisted thoracoscopic surgery (VATS) lobectomy in patients with pathological T1 (pT1) stage lung cancer.

METHODS

Between January 2019 and March 2022, patients with pulmonary neoplasms who underwent 2-3 cm SP VATS lobectomy were retrospectively screened. After propensity-matched analysis, we compared perioperative outcomes and analyzed the safety and feasibility of PMB and MSC of the bronchial stump while performing VATS lobectomy.

RESULTS

In this study, 280 and 832 patients were enrolled in the PMB and MSC groups, respectively. Propensity score matching produced 280 pairs. The operation time was shorter in the PMB group, whereas the average number of lymph nodes dissected was higher in the PMB group. The conversion rate was significantly lower in the PMB group. The following were similar between the PMB and MSC groups, respectively: average blood loss volume, postoperative hospital stay, and chest tube removal time. Postoperatively, the incidence of atelectasis was significantly higher in the MSC group. As per subgroup analyses, PMB was associated with a shorter operation time in left and right upper lobectomies. Particularly in left upper lobectomy, PMB had more lymph node dissections and less conversion to open and postoperative atelectasis.

CONCLUSIONS

In comparison with MSC of the bronchial stump, PMB showed better safety and feasibility in 2-3 cm SP VATS left and right superior lobectomies in patients with pT1 stage lung cancer.

Congenital lung abnormalities on magnetic resonance imaging: the CLAM study

OBJECTIVES

Follow-up of congenital lung abnormalities (CLA) is currently done with chest computer tomography (CT). Major disadvantages of CT are exposure to ionizing radiation and need for contrast enhancement to visualise vascularisation. Chest magnetic resonance imaging (MRI) could be a safe alternative to image CLA without using contrast agents. The objective of this cohort study was to develop a non-contrast MRI protocol for the follow-up of paediatric CLA patients, and to compare findings on MRI to postnatal CT in school age CLA patients.

METHODS

Twenty-one CLA patients, 4 after surgical resection and 17 unoperated (mean age 12.8 (range 9.4-15.9) years), underwent spirometry and chest MRI. MRI was compared to postnatal CT on appearance and size of the lesion, and lesion associated abnormalities, such as hyperinflation and atelectasis.

RESULTS

By comparing school-age chest MRI to postnatal CT, radiological appearance and diagnostic interpretation of the type of lesion changed in 7 (41%) of the 17 unoperated patients. In unoperated patients, the relative size of the lesion in relation to the total lung volume remained stable (0.9% (range - 6.2 to + 6.7%), p = 0.3) and the relative size of lesion-associated parenchymal abnormalities decreased (- 2.2% (range - 0.8 to + 2.8%), p = 0.005).

CONCLUSION

Non-contrast-enhanced chest MRI was able to identify all CLA-related lung abnormalities. Changes in radiological appearance between MRI and CT were related to CLA changes, patients' growth, and differences between imaging modalities. Further validation is needed for MRI to be introduced as a safe imaging method for the follow-up of paediatric CLA patients.

KEY POINTS

• Non-contrast-enhanced chest MRI is able to identify anatomical lung changes related to congenital lung abnormalities, including vascularisation. • At long-term follow-up, the average size of congenital lung abnormalities in relation to normal lung volume remains stable. • At long-term follow-up, the average size of congenital lung abnormalities associated parenchymal abnormalities such as atelectasis in relation to normal lung volume decreases.

Pulmonary aspergillus infection with abnormal imaging successfully treated with omalizumab: A case report

BACKGROUND

Pulmonary aspergillosis is a pulmonary infectious disease that is clinically difficult to diagnose and treat. When the lower respiratory tract is invaded by Aspergillus, the clinical manifestations and imaging features vary among patients with different immune states. The use of antifungal drugs and glucocorticoids are important, but some patients do not respond satisfactorily to treatment.

CASE PRESENTATION

A 59-year-old female had a long history of asthma and poor symptom control, with long-term use of long-acting inhaled glucocorticoids combined with a long-acting β2 receptor agonists (ICS + LABA) (salmeterol fluticasone inhalation powder). The ground glass shadow, tree-in-bud sign, and bronchiectasis in the middle lobe of the right lung and the lower lobe of both lungs were first detected by chest CT over 5 years ago. Atelectasis in the middle lobe of the right lung was detected over 3 years ago. Over 2 years ago, the patient was hospitalized and a repeat chest CT showed persistent atelectasis in the middle lobe of the right lung, and more lesions in bilateral lower lungs than before. Aspergillus fumigatus was detected in alveolar lavage fluid and sputum pathogenic culture, which confirmed the diagnosis of pulmonary aspergillosis. After treatment with voriconazole and amphotericin B, the middle lobe of the right lung partially reopened, but the lesions in bilateral lower lungs persisted. After 21 weeks of treatment, the antifungal drugs were stopped because the patient refused to use oral/intravenous glucocorticoids, and omalizumab was finally chosen for treatment. After 1 month of treatment, the patient's clinical symptoms began to ease. After 1 year of treatment, imaging reexamination of lung showed that the lesions were completely cleared, accompanied by significant improvement in nutritional status and airway function.

CONCLUSIONS

We reported the case of a patient with pulmonary Aspergillus infection who was treated with omalizumab and showed significant improvement in clinical symptoms and imaging abnormalities, which provides a new option for patients with pulmonary Aspergillus infection who show unsatisfactory response with first-line drugs.

[Clinical characteristics of plastic bronchitis and risk factors for recurrence in children]

OBJECTIVES

To study the clinical characteristics of plastic bronchitis (PB) in children and investigate the the risk factors for recurrence of PB.

METHODS

This was a retrospective analysis of medical data of children with PB who were hospitalized in Children's Hospital of Chongqing Medical University from January 2012 to July 2022. The children were divided into a single occurrence of PB group and a recurrent PB group and the risk factors for recurrence of PB were analyzed.

RESULTS

A total of 107 children with PB were included, including 61 males (57.0%) and 46 females (43.0%), with a median age of 5.0 years, and 78 cases (72.9%) were over 3 years old. All the children had cough, 96 children (89.7%) had fever, with high fever in 90 children. Seventy-three children (68.2%) had shortness of breath, and 64 children (59.8%) had respiratory failure. Sixty-six children (61.7%) had atelectasis and 52 children (48.6%) had pleural effusion. Forty-seven children (43.9%) had Mycoplasma pneumoniae infection, 28 children (26.2%) had adenovirus infection, and 17 children (15.9%) had influenza virus infection. Seventy-one children (66.4%) had a single occurrence of PB, and 36 cases (33.6%) had recurrent occurrence of PB (≥2 times). Multivariate logistic regression analysis showed that involvement of ≥2 lung lobes (OR=3.376) under bronchoscopy, continued need for invasive ventilation after initial removal of plastic casts (OR=3.275), and concomitant multi-organ dysfunction outside the lungs (OR=2.906) were independent risk factors for recurrent occurrence of PB (P<0.05).

CONCLUSIONS

Children with pneumonia accompanied by persistent high fever, shortness of breath, respiratory failure, atelectasis or pleural effusion should be highly suspected with PB. Involvement of ≥2 lung lobes under bronchoscopy, continued need for invasive ventilation after initial removal of plastic casts, and concomitant multi-organ dysfunction outside the lungs may be risk factors for recurrent occurrence of PB.

Cardiac surgery in East Africa: a profile of cases and referral to physiotherapy

Background

A significant increase in cardiac surgery has been observed globally, with prolonged length of stay (LOS) still prevalent due to post-operative complications. Physiotherapy pre and post cardiac surgery is known to reduce these complications and LOS, however cases referred for physiotherapy is unknown.

Objective

The study aimed to describe the profile and pre- and post-operative referrals to physiotherapy of patients admitted to the cardiothoracic unit at a selected hospital in Tanzania over a four-year period.

Method

Descriptive, retrospective design. A data extraction sheet was used to capture demographic, cardiac disease, ICU and hospital LOS, post-operative complications and physiotherapy referral data of all patients ≥18 years of age.

Results

105 cardiac surgeries were performed. Patients' mean age was 30.6 years (SD=10.48) and 54.3% (n=57/105) were female. Cardiac surgeries performed declined from 48.6% (n=51/105) in 2010 to 10.5% (n=11/105) in 2013. Cardiac arrest (33%, n=7/21), pneumonia (19%, n=4/21) and lung collapse (4.8%, n=1/21) were the notable documented post-operative complications. ICU mortality was highest (72,7%, n=8/11). Only 1% (n=1/105) of cases were referred pre-operatively versus 77.7% (n=80/103) post-operatively for physiotherapy.

Conclusion

Cardiac surgeries were reduced annually but the post-operative complications need to be reduced. Pre-operative physiotherapy referral may reduce pneumonia and lung collapse following cardiac surgery.

A Rare Complication of Anomalous Left Coronary Artery From the Pulmonary Artery Identified by Point-of-Care Ultrasound

ABSTRACT

Point-of-care ultrasound is a valuable tool in the evaluation of undifferentiated respiratory distress in children. This case report describes a 9-month-old male infant who presented with 4 months of progressively worsening cough and was found to be tachypneic in the emergency department. Chest radiography revealed complete opacification of the left hemithorax with cardiomegaly. Point-of-care ultrasound demonstrated atelectasis of the entire left lung and severe dilation of the left ventricle with poor function. Electrocardiogram and echocardiogram findings were consistent with a diagnosis of anomalous left coronary artery from the pulmonary artery. The patient underwent successful cardiac surgery to improve myocardial perfusion. Bronchoscopy visualized the etiology of his atelectasis, pulsatile compression of the left mainstem bronchus by the dilated heart. Focused cardiac and lung ultrasound techniques, as well as pertinent sonographic findings, are reviewed.

Cabin Pressure Altitude Effect on Acceleration Atelectasis After Agile Flight Breathing 60% Oxygen

INTRODUCTION: A flight trial was conducted to determine whether breathing 60% oxygen during high performance flight maneuvers using contemporary pilot flight equipment induces atelectasis and to explore whether cabin altitude had any influence on the extent of atelectasis identified.METHODS: On 2 separate days, 14 male aircrew flew as passengers at High [14,500-18,000 ft (4420-5486 m)] and Low [4000-6000 ft (1219-1829 m)] cabin pressure altitude in a Hawk T Mk1 aircraft breathing 60% oxygen. Sorties comprised 16 maneuvers at +5 G_z, each sustained for 30 s. Lung volumes (spirometry), basal lung volume (electrical impedance tomography, EIT), and peripheral oxygen saturation during transition from hyperoxia to hypoxia (pulmonary shunt fraction) were measured in the cockpit immediately before (Pre) and after (Post) flight.RESULTS: Forced inspiratory vital capacity (FIVC) was significantly lower Postflight after High (-0.24 L) and Low (-0.38 L) sorties, but recovered to Preflight values by the fourth repeat (FIVC4). EIT-derived measures of FIVC decreased after High (-3.3%) and Low (-4.4%) sorties but did not recover to baseline by FIVC4. FIVC reductions were attributable to decreased inspiratory capacity. S_po₂ was lower Postflight than Preflight in High and Low sorties.DISCUSSION: Breathing 60% oxygen during flight results in a 3.8-4.9% reduction in lung volume associated with a small decrease in blood oxygenation and an estimated pulmonary shunt of up to 5.7%. EIT measures suggest persisting airway closure despite repeated FIVC maneuvers. There was no meaningful influence of cabin pressure altitude. The operational consequence of the observed changes is likely to be small.Tank H, Kennedy G, Pollock R, Hodkinson P, Sheppard-Hickey R-A, Woolford J, Green NDC, Stevenson A. Cabin pressure altitude effect on acceleration atelectasis after agile flight breathing 60% oxygen. Aerosp Med Hum Perform. 2023; 94(1):3-10.

Use of rocuronium and sugammadex for video-assisted thoracoscopic surgery is associated with reduced duration of chest tube drainage: a propensity score-matched analysis

BACKGROUND

We investigated the influence of different neuromuscular blocking agents and reversal agents during anaesthesia on early removal of chest tube drainage after video-assisted thoracoscopic surgery (VATS).

METHODS

This retrospective single-centre study included patients who underwent VATS after tracheal intubation under general anaesthesia. Patients received either cisatracurium and neostigmine (n=547) or rocuronium and sugammadex (n=151). Quantitative neuromuscular monitoring was used and one chest tube (size 24 Fr) was inserted. To reduce potential bias, 140 patients from each group were matched by propensity score for sex, age, body mass index and indication for VATS. Primary outcome was duration of chest tube drainage after surgery.

RESULTS

Use of rocuronium and sugammadex was associated with a shorter duration of chest tube drainage (2 [1-2] vs 2 [1-3] days; P=0.049) and a 63% reduction in delayed chest tube removal (odds ratio 0.37; 95% confidence interval [CI]: 0.20-0.67; P=0.005). This group also had a lower incidence of postoperative atelectasis (P=0.047) and consolidation (P=0.008). Each 1 h increase in the duration of anaesthesia was associated with a 1.57-fold increase in the delayed removal of the chest tube (95% CI: 1.25-1.96; P=0.005).

CONCLUSIONS

During general anaesthesia for VATS, compared with cisatracurium and neostigmine, use of rocuronium and sugammadex was associated with a significant decrease in the incidence of postoperative delayed removal of the chest tube, atelectasis, and pulmonary consolidation.

Identification of risk factors for postoperative pulmonary complications in general surgery patients in a low-middle income country

BACKGROUND

Postoperative pulmonary complications (PPCs) are an important cause of perioperative morbidity and mortality. Although risk factors for PPCs have been identified in high-income countries, less is known about PPCs and their risk factors in low- and middle-income countries, such as South Africa. This study examined the incidence of PPCs and their associated risk factors among general surgery patients in a public hospital in the province of KwaZulu-Natal, South Africa to inform future quality improvement initiatives to decrease PPCs in this clinical population.

METHODS

A retrospective secondary analysis of adult patients with general surgery admissions from January 1, 2013 to December 31, 2017 was conducted using data from the health system's Hybrid Electronic Medical Registry. The sample was comprised of 5352 general surgery hospitalizations. PPCs included pneumonia, atelectasis, acute respiratory distress syndrome, pulmonary edema, pulmonary embolism, prolonged ventilation, hemothorax, pneumothorax, and other respiratory morbidity which encompassed empyema, aspiration, pleural effusion, bronchopleural fistula, and lower respiratory tract infection. Risk factors examined were age, tobacco use, number and type of pre-existing comorbidities, emergency surgery, and number and type of surgeries. Bivariate and multivariable logistic regression models were conducted to identify risk factors for developing a PPC.

RESULTS

The PPC rate was 7.8%. Of the 418 hospitalizations in which a patient developed a PPC, the most common type of PPC was pneumonia (52.4%) and the mortality rate related to the PPC was 11.7%. Significant risk factors for a PPC were increasing age, greater number of comorbidities, emergency surgery, greater number of general surgeries, and abdominal surgery.

CONCLUSIONS

PPCs are common in general surgery patients in low- and middle-income countries, with similar rates observed in high-income countries. These complications worsen patient outcomes and increase mortality. Quality improvement initiatives that employ resource-conscious methods are needed to reduce PPCs in low- and middle-income countries.

Diagnostic Accuracy of Multiple D-Dimer Cutoff Thresholds and Other Clinically Applicable Biomarkers for the Detection and Radiographic Evaluation of Pulmonary Embolism

Background: Diagnostic work-up of pulmonary embolism (PE) remains a challenge. Methods: We retrospectively studied all patients referred for computed tomography pulmonary angiography (CTPA) with suspicion of PE during a 12-month period (2018). The diagnostic accuracy of different D-dimer (Dd) cutoff thresholds for ruling out PE was evaluated. Furthermore, the association of Dd and red cell distribution width (RDW) with embolus location, CTPA findings, and patient outcome was recorded. Results: One thousand seventeen (n = 1017) patients were finally analyzed (mean age: 64.6 years (SD = 11.8), males: 549 (54%)). PE incidence was 18.7%. Central and bilateral embolism was present in 44.7% and 59.5%, respectively. Sensitivity and specificity for conventional and age-adjusted Dd cutoff was 98.2%, 7.9%, and 98.2%, 13.1%, respectively. A cutoff threshold (2.1 mg/L) with the best (64.4%) specificity was identified based on Receiver Operating Characteristics analysis. Moreover, a novel proposed Dd cutoff (0.74 mg/L) emerged with increased specificity (20.5%) and equal sensitivity (97%) compared to 0.5 mg/L, characterized by concurrent reduction (17.2%) in the number of performed CTPAs. Consolidation/atelectasis and unilateral pleural effusion were significantly associated with PE (p < 0.05, respectively). Patients with consolidation/atelectasis or intrapulmonary nodule(s)/mass on CTPA exhibited significantly greater median Dd values compared to patients without the aforementioned findings (2.34, (IQR 1.29−4.22) vs. 1.59, (IQR 0.81−2.96), and 2.39, (IQR 1.45−4.45) vs. 1.66, (IQR 0.84−3.12), p < 0.001, respectively). RDW was significantly greater in patients who died during hospitalization (p = 0.012). Conclusions: Age-adjusted Dd increased diagnostic accuracy of Dd testing without significantly decreasing the need for imaging. The proposed Dd value (0.74 mg/L) showed promise towards reducing considerably the need of CTPA. Multiple radiographic findings have been associated with increased Dd values in our study.

Multi-Level Classification of Lung Pathologies in Neonates using Recurrence Features

The use of Lung Ultrasound (LUS) as a tool to diagnose and monitor lung diseases in neonates has increased in urban hospitals. LUS's main advantages compared to chest CT or X-rays is that it is less expensive, more accessible, and does not expose the patient to radiation. Performing LUS on neonates and diagnosing the LUS images require highly trained medical professional and clinicians. While availability of such specialists in general is not an issue in urban areas, there is lack of such personnel in rural and remote communities. Hence, an automated computer-aided screening approach as a first level diagnosis assistance in such scenarios might be of significant value. Many of the image morphologies used by clinicians in diagnosing the LUS have strong recurrence characteristics. Building upon this knowledge, in this paper, we propose a feature extraction method designed to quantify such recurrent features for classification of LUS images into 6 common neonatal lung conditions. These conditions were normal lung, chronic lung disease (CLD), transient tachypnea of the newborn (TTN), pneumothorax (PTX), respiratory distress syndrome (RDS), and consolidation (CON) that could be pneumonia or atelectasis. The proposed method extracts virtual scanlines from the LUS images and converts them into signals. Then using recurrence quantification analysis (RQA), features were extracted and fed to pattern classifiers. Using a simple linear classifier the proposed features can achieve a classification accuracy of 69.3% without clinical features and 77.6% with clinical features. Clinical Relevance- Development of an automated computer-aided screening tool for first level diagnosis assistance in neonatal LUS pathologies. Such a tool will be of significant value in rural and remote medical communities.

Lung ultrasound is non-inferior to bronchoscopy for confirmation of double-lumen endotracheal tube positioning: a randomized controlled noninferiority study

BACKGROUND

Appropriate placement of left-sided double-lumen endotracheal tubes (LDLTs) is paramount for optimal visualization of the operative field during thoracic surgeries that require single lung ventilation. Appropriate placement of LDLTs is therefore confirmed with fiberoptic bronchoscopy (FOB) rather than clinical assessment alone. Recent studies have demonstrated lung ultrasound (US) is superior to clinical assessment alone for confirming placement of LDLT, but no large trials have compared US to the gold standard of FOB. This noninferiority trial was devised to compare lung US with FOB for LDLT positioning and achievement of lung collapse for operative exposure.

METHODS

This randomized, controlled, double-blind, noninferiority trial was conducted at the Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand from October 2017 to July 2019. The study enrolled 200 ASA classification 1-3 patients that were scheduled for elective thoracic surgery requiring placement of LDLT. Study patients were randomized into either the FOB group or the lung US group after initial blind placement of LDLT. Five patients were excluded due to protocol deviation. In the FOB group (n = 98), fiberoptic bronchoscopy was used to confirm lung collapse due to proper positioning of the LDLT, and to adjust the tube if necessary. In the US group (n = 97), lung ultrasonography of four pre-specified zones (upper and lower posterior and mid-axillary) was used to assess lung collapse and guide adjustment of the tube if necessary. The primary outcome was presence of adequate lung collapse as determined by visual grading by the attending surgeon on scale from 1 to 4. Secondary outcomes included the time needed to adjust and confirm lung collapse, the time from finishing LDLT positioning to the grading of lung collapse, and intraoperative parameters such has hypotension or hypertension, hypoxia, and hypercarbia. The patient, attending anesthesiologist, and attending thoracic surgeon were all blinded to the intervention arm.

RESULTS

The primary outcome of lung collapse by visual grading was similar between the intervention and the control groups, with 89 patients (91.8%) in the US group compared to 83 patients (84.1%) in the FOB group (p = 0.18) experiencing adequate collapse. This met criteria for noninferiority per protocol analysis. The median time needed to confirm and adjust LDLT position in the US group was 3 min (IQR 2-5), which was significantly shorter than the median time needed to perform the task in the FOB group (6 min, IQR 4-10) (p = 0.002).

CONCLUSIONS

In selected patients undergoing thoracic surgery requiring LDLT, lung ultrasonography was noninferior to fiberoptic bronchoscopy in achieving adequate lung collapse and reaches the desired outcome in less time.

TRIAL REGISTRATION

This study was registered at clinicaltrials.gov, NCT03314519 , Principal investigator: Kasana Raksamani, Date of registration: 19/10/2017.

Causes and Treatment of Hypoxia during Total Hip Arthroplasty in Elderly Patients: A Case Report

Intraoperative hypoxia occurs in approximately 6.8% of surgeries and requires appropriate management to avoid poor outcomes, such as increased mortality or extended hospitalization. Hypoxia can be caused by a variety of factors, including laryngospasm, inhalational anesthetics, and surgery for abdominal pathology or hip fractures. In particular, elderly patients are more vulnerable to hypoxia due to their existing lung diseases or respiratory muscle weakness. This study presents the cases of two elderly patients who developed hypoxia during total hip arthroplasty under general anesthesia. Positive end expiratory pressure, the recruitment maneuver, and increased fraction of inspired oxygen improved hypoxia only temporarily, and patients’ oxygen saturation level again dropped to 79–80%. We suspected that hypoxia was caused by atelectasis and, therefore, resumed spontaneous respiration. Thereafter, both the patients showed an improvement in hypoxia. Intraoperative hypoxia that is suspected to be caused by atelectasis can be improved by securing sufficient lung volume for respiration through increased muscle tone with spontaneous respiration.

Indirect Measurements of Acceleration Atelectasis and the Role of Inspired Oxygen Concentrations

BACKGROUND: A growing number of symptom reports suggestive of acceleration atelectasis in fast jet aircrew have raised the question as to whether traditional guidelines on inspired gas composition remain valid. The aim of this study was to assess the effects of inspired O₂ concentration on the development of acceleration atelectasis when wearing modern anti-G garments. METHODS: There were 14 nonaircrew subjects who completed 5 centrifuge exposures to +5 G_z lasting 90 s. During exposures subjects breathed a gas mixture containing 21, 35, 45, 60, or 75% O₂. To assess the extent of atelectasis post-G_z, forced inspiratory vital capacity (FIVC), regional FIVC (EIT_FIVC), shunt, respiratory resistance, reactance, and compliance and peripheral O₂ saturation during a hypoxic exposure were measured. RESULTS: Compared with baseline, FIVC was not statistically significantly altered. EIT_FIVC was 14.4% lower after the 75% O₂ exposure only with a greater symptom reporting with higher F_IO₂ in some individuals. A significantly greater shunt (3>6%) followed the 60 and 75% O₂ exposures. O₂ concentration during G_z had no effect on respiratory resistance, reactance, compliance, or hypoxemia. DISCUSSION: There is evidence of mild acceleration atelectasis present when breathing 60% O₂, particularly in susceptible individuals, with 75% O₂ causing more obvious physiological compromise. An inspired oxygen concentration of <60% will prevent the majority of individuals from developing acceleration atelectasis. Pollock RD, Gates SD, Radcliffe JJ, Stevenson AT. Indirect measurements of acceleration atelectasis and the role of inspired oxygen concentrations. Aerosp Med Hum Perform. 2021; 92(10):780785.

Monitoring postoperative lung recovery using electrical impedance tomography in post anesthesia care unit: an observational study

With electrical impedance tomography (EIT) recruitment and de-recruitment phenomena can be quantified and monitored at bedside. The aim was to examine the feasibility of EIT with respect to monitor atelectasis formation and resolution in the post anesthesia care unit (PACU). In this observational study, 107 postoperative patients were investigated regarding the presence and recovery of atelectasis described by the EIT-derived parameters Global Inhomogeneity Index (GI Index), tidal impedance variation (TIV), and the changes in end-expiratory lung impedance (ΔEELI). We examined whether the presence of obesity (ADP group) has an influence on pulmonary recovery compared to normal weight patients (NWP group). During the stay at PACU, measurements were taken every 15 min. GI Index, TIV, and ΔEELI were calculated for each time point. 107 patients were monitored and EIT-data of 16 patients were excluded for various reasons. EIT-data of 91 patients were analyzed off-line. Their length of stay averaged 80 min (25th and 75th quartile 52–112). The ADP group demonstrated a significantly higher GI Index at PACU arrival (p < 0.001). This finding disappeared during their stay at the PACU. Additionally, the ADP group showed a significant increase in ΔEELI between PACU arrival and discharge (p = 0.025). Furthermore, TIV showed a significantly lower value during the first 90 min of PACU stay as compared to the time period thereafter (p = 0.036). Our findings demonstrate that obesity has an influence on intraoperative atelectasis formation and de-recruitment during PACU stay. The application of EIT in spontaneously breathing PACU patients seems meaningful in monitoring pulmonary recovery.

Effect of inspiratory muscle training associated or not to physical rehabilitation in preoperative anatomic pulmonary resection: a systematic review and meta-analysis

OBJECTIVE

The aim of this study is to systematically review the effect of inspiratory muscle training (IMT) associated or not with physical rehabilitation in the preoperative period of anatomical pulmonary resection.

METHODS

Search in the databases: MEDLINE, Cochrane CENTRAL, EMBASE, LILACS and PEDro up to November 2019. Randomized clinical trials (RCTs) were included in adults in the preoperative period of pulmonary resection. The selection of studies and data extraction was performed by two independent reviewers. The risk of bias assessed with RoB 2.0 and the quality of evidence with GRADE.

PROSPERO

CRD42018105859.

RESULTS

Six RCTs were included; patients who underwent IMT in the preoperative period showed a significant improvement in functional capacity assessed by the 6-min walk test (6WT) (MD 28,93 [IC 95% 0,28; 57,58], p = 0,04, I² = 0%) and significantly reduced the length of hospital stay (MD -3,63 [IC 95% -4,96; -2,29], p = 0,00, I² = 0%). There was no significant difference between groups regarding pulmonary function, in postoperative complications such as pneumonia (RR 0,56 [IC 95% 0,29; 1,10], p = 0,09, I² = 0%), atelectasis (RR 0,81 [IC 95% 0,24; 2,69], p = 0,72, I² = 0%), mechanical ventilation > 48 h (RR 0,43 [IC 95% 0,12; 1,58], p = 0,20, I² = 0%), in mortality (RR 0,33 [IC 95% 0,04; 3,12], p = 0,33, I² = 0%), and quality of life.

CONCLUSION

IMT associated with physical exercise in the preoperative period of pulmonary resection improves functional capacity and reduces the length of hospital stay in the postoperative period.

Effect of Recruitment Maneuvers and PEEP on Respiratory Failure After Cardiothoracic Surgery in Obese Subjects: A Randomized Controlled Trial

BACKGROUND

Obesity may increase the risk of respiratory failure after cardiothoracic surgery. A recruitment maneuver followed by PEEP might decrease the risk of respiratory failure in obese subjects. We hypothesized that the routine use after heart surgery of a recruitment maneuver followed by high or low PEEP level would decrease the frequency of respiratory failure in obese subjects.

METHODS

In a pragmatic, randomized controlled trial, we assigned obese subjects (ie, with body mass index [BMI] ≥ 30 kg/m²) in the immediate postoperative period of cardiothoracic surgery to either volume control ventilation with 5 cm H₂O of PEEP (control group) or a recruitment maneuver followed by 5 or 10 cm H₂O of PEEP in the intervention arms (RM5 and RM10 groups, respectively). The primary outcome was the proportion of subjects with postextubation respiratory failure, defined as the need for re-intubation, bi-level positive airway pressure, or high-flow nasal cannula within the first 48 h.

RESULTS

The study included 192 subjects: 65 in the control group (BMI 33.5 ± 3.2 kg/m²), 66 in the RM5 group (BMI 34.5 ± 3.2 kg/m², and 61 in RM10 group (BMI 33.8 ± 4.8 kg/m²). Postextubation respiratory failure occurred in 14 subjects in the control group (21.5% [95% CI 13.3-35.3]), 21 subjects in the RM5 group (31.8% [95% CI 21.2-44.6]), and 9 subjects in the RM10 group (14.7% [95% CI 7.4-26.7]) (P = .07). The recruitment maneuver was stopped prematurely due to severe hypotension in 8 (12.1%) RM5 subjects and in 4 (6.6%) RM10 subjects (P = .28). There were no significant differences between the 3 groups for the frequencies of atelectasis, pneumonia, and death in the ICU.

CONCLUSIONS

The routine use after heart surgery of a recruitment maneuver followed by 5 or 10 cm H₂O of PEEP did not decrease the frequency of respiratory failure in obese subjects. A recruitment maneuver followed by 5 cm H₂O of PEEP is inappropriate.

Double-lumen endotracheal tubes and bronchial blockers exhibit similar lung collapse physiology during lung isolation

PURPOSE

Double-lumen endotracheal tubes (DL-ETT) and bronchial blockers (BB) are frequently used to allow one-lung ventilation (OLV) during video-assisted thoracic surgery (VATS). Recently, faster lung collapse has been documented with a BB than with a DL-ETT. The physiologic mechanisms behind this faster collapse remained unknown. We aimed to measure ambient air absorption (Vresorb) and intra-bronchial pressure (Pairway) into the non-ventilated lung during OLV using DL-ETT and BB.

METHODS

Patients undergoing VATS and OLV for lung resection were randomly assigned to have measurements made of Vresorb or Pairway within the non-ventilated lung using either a DL-ETT or BB.

RESULTS

Thirty-nine patients were included in the analyses. The mean (standard error of the mean [SEM]) Vresorb was similar in the DL-ETT and BB groups [504 (85) vs 630 (86) mL, respectively; mean difference, 126; 95% confidence interval [CI], -128 to 380; P = 0.31]. The mean (SEM) Pairway became progressively negative in the non-ventilated lung in both the DL-ETT and the BB groups reaching [-20 (5) and -31 (10) cmH2O, respectively; mean difference, -11; 95% CI, -34 to 12; P = 0.44] at the time of the pleural opening.

CONCLUSIONS

During OLV before pleural opening, entrainment of ambient air into the non-ventilated lung occurs when the lumen of the lung isolation device is kept open. This phenomenon is prevented by occluding the lumen of the isolation device before pleural opening, resulting in a progressive build-up of negative pressure in the non-ventilated lung. Future clinical studies are needed to confirm these physiologic results and their impact on lung collapse and operative outcomes.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT02919267); registered 28 September 2016.

Non-ventilated lung deflation during one-lung ventilation with a double-lumen endotracheal tube: a randomized-controlled trial of occluding the non-ventilated endobronchial lumen before pleural opening

PURPOSE

Lung deflation during one-lung ventilation (OLV) is thought to be faster using a double-lumen endotracheal tube (DL-ETT) than with a bronchial blocker, especially when the non-ventilated lumen is opened to allow egress of air from the operative lung. Nevertheless, ambient air can also be entrained into the non-ventilated lumen before pleural opening and subsequently delay deflation. We therefore hypothesized that occluding the non-ventilated DL-ETT lumen during OLV before pleural opening would prevent air entrainment and consequently enhance operative lung deflation during video-assisted thoracoscopic surgery (VATS).

METHODS

Thirty patients undergoing VATS using DL-ETT to allow OLV were randomized to having the lumen of the operative lung either open (control group) or occluded (intervention group) to ambient air. The primary outcome was the time to lung collapse evaluated intraoperatively by the surgeons. The T50, an index of rate of deflation, was also determined from a probabilistic model derived from intraoperative video clips presented in random order to three observers.

RESULTS

The median [interquartile range] time to lung deflation occurred faster in the intervention group than in the control group (24 [20-37] min vs 54 [48-68] min, respectively; median difference, 30 min; 95% confidence interval [CI], 14 to 46; P < 0.001). The estimated T50 was 32.6 min in the intervention group compared with 62.3 min in the control group (difference, - 29.7 min; 95% CI, - 51.1 to - 8.4; P = 0.008).

CONCLUSION

Operative lung deflation during OLV with a DL-ETT is faster when the operative lumen remains closed before pleural opening thus preventing it from entraining ambient air during the closed chest phase of OLV.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT03508050); registered 27 September 2017.

Peribronchial Connective Tissue Infection Caused by Bifidobacterium longum and Veillonella Species Mimicking Lung Cancer

An 86-year-old woman was admitted for the investigation of atelectasis of the upper lobe of her right lung with a mass shadow in the hilum (Golden S sign). Chest computed tomography revealed swollen connective tissue around the right bronchus, and needle aspirate grew Bifidobacterium longum and Veillonella species. She was diagnosed with peribronchial connective tissue infection, and her condition improved with antibiotics. Although this sign is strongly suggestive of malignant disease, benign disease should be considered in the differential diagnosis. Pulmonary infection caused by Bifidobacterium longum is extremely rare; however, clinicians should consider it as a possible cause of pulmonary infections.

Case of a 21-year-old man with persistent lung collapse leading to a pericardectomy linked to vape use

This case report describes multiple organ failure in a young man with illicit vape use which he did not initially disclose to his health care providers. His symptoms were not readily diagnosed until he experienced lung collapse and significant heart failure. Treatment plan recommendations varied among health care providers leading to increased anxiety for the patient and his family. It was ultimately determined that illicit vape use along with chronic substance abuse contributed to a respiratory virus causing pulmonary collapse. The pulmonary virus migrated to the patient's heart causing severe restrictive pericarditis ultimately requiring a pericardectomy. Assessment, interventions, and follow-up care occurred during the global Corona-19 pandemic of 2020.

[Influencing factors for the clinical effect of bronchoalveolar lavage in children with Mycoplasma pneumoniae pneumonia and atelectasis]

OBJECTIVE

To study the influencing factors for the clinical effect of bronchoalveolar lavage (BAL) in children with Mycoplasma pneumoniae pneumonia (MPP) and atelectasis.

METHODS

A total of 75 children with MPP and atelectasis were divided into a good response group with 51 children and a poor response group with 24 children according to the clinical effect of BAL treatment. LASSO logistic regression analysis was used to investigate the factors influencing the clinical effect of BAL treatment. The receiver operating characteristic (ROC) curve and restricted cubic spline model analysis were used to evaluate the value of the course of the disease at the time of BAL treatment in predicting the clinical effect of BAL treatment.

RESULTS

Compared with the good response group, the poor response group had a significantly lower percentage of lymphocytes in bronchoalveolar lavage fluid, a significantly higher proportion of children with atelectasis of two or more lung lobes or stenosis of the bronchial cavity or opening caused by inflammation, and a significantly longer course of the disease at the time of BAL treatment and azithromycin treatment (P<0.05). The LASSO logistic regression analysis showed that a prolonged course of the disease at the time of BAL treatment (OR=1.23), atelectasis of two or more lung lobes (OR=11.99), and stenosis of the bronchial cavity or opening caused by inflammation (OR=5.31) were independent risk factors for poor clinical effect of BAL treatment (P<0.05). The ROC curve analysis showed that the course of disease of ≥11.5 days at the time of BAL treatment suggested a poor clinical effect of BAL treatment, with a sensitivity of 91.7% and a specificity of 54.9%. The restricted cubic spline model analysis showed that there was a non-linear dose-response relationship between the course of disease at the time of BAL treatment and the clinical effect of BAL treatment (P<0.05).

CONCLUSIONS

Early BAL treatment may have a good clinical effect in children with MPP and atelectasis. Atelectasis of two or more lung lobes and inflammation-induced stenosis of the bronchial cavity or opening shown under bronchoscope may indicate a poor clinical effect of BAL treatment.