High altitude trekking after lung transplantation: a prospective study using lung ultrasound to detect comets tails for interstitial pulmonary edema in lung transplant recipients and healthy volunteers

Telléz L, Tuta-Quintero E, Rincón A, Casas D, Rodriguez C, Mendoza D, Giraldo-Cadavid LF. Impact of Pulmonary Hypertension on Posttransplant Survival of Patients With Pulmonary Fibrosis at High Altitude: A Prospective Cohort Study

Background: Pulmonary hypertension (PH) in patients undergoing lung transplantation (LT) for pulmonary fibrosis can impair lung function, reduce physical activity, and decrease survival. However, data on outcomes at 1 and 5 years of follow-up remain limited. Methods: In this prospective cohort study, pulmonary function, the 6-min walk test (6MWT), and the St. George's Respiratory Questionnaire (SGRQ) were assessed pretransplant, at hospital discharge, and at 3, 6, and 12 months posttransplant. Additionally, minimal clinically important differences (MCIDs) between patients with and without PH were evaluated. Survival rates were calculated using the Kaplan-Meier method and analyzed using the log-rank test. Results: The study included 39 patients undergoing LT for pulmonary fibrosis. Of these, 82% (32/39) had PH, with a median age of 52.6 years (SD: 10.2). In both the PH and non-PH groups, lung function, 6MWD, and SGRQ total scores showed progressive improvement from pre-LT to 1 year posttransplant. Patients without PH demonstrated MCID in 6MWT and SGRQ total scores from pre-LT through the 6- and 12-month follow-up. The overall 1-year survival rate was 84.6%, with an average survival of 10.51 months (95% CI: 9.29-11.73). The 5-year overall survival rate was 61.5%, with an average survival of 44.89 months (95% CI: 37.62-52.16). No statistically significant differences in survival were found based on sex (p=0.322 and 0.206), mean pulmonary artery pressure (mPAP) (p=0.232 and 0.486), age (p=0.375 and 0.959), or body mass index (BMI) (p=0.884 and 0.594) at 1 and 5 years. Conclusion: Survival at 1 and 5 years was lower in patients with PH. However, no significant differences in survival were observed based on sex, mPAP, age, or BMI. Statistically significant improvements in FVC, FEV1, 6MWT, and SGRQ total scores were observed both before and after LT, continuing through 1 year of follow-up. The 6MWT and SGRQ showed MCID both prior to surgery and during follow-up at 6 and 12 months, in both PH and non-PH patients.

Physical Exercise After Solid Organ Transplantation: A Cautionary Tale

An increasing body of randomized controlled trials suggests the safety of engaging in moderate to vigorous intensity exercise training following solid organ transplantation. Fueled by emerging sport events designed for transplant recipients and the ever-growing body of research highlighting the diverse health benefits of physical activity, transplant recipients are now increasingly participating in strenuous and occasionally competitive physical endeavors that largely surpass those evaluated in controlled research settings. This viewpoint article adopts a cautionary stance to counterbalance the prevalent one-sided optimistic perspective regarding posttransplant physical activity. While discussing methodological limitations, we explore plausible adverse impacts on the cardiovascular, immunological, and musculoskeletal systems. We also examine the physiological consequences of exercising in the heat, at high altitude, and in areas with high air pollution. Risks associated with employing performance-enhancing strategies and the conceivable psychological implications regarding physical activity as a tribute to the 'gift of life' are discussed. With a deliberate focus on the potential adverse outcomes of strenuous posttransplant physical activity, this viewpoint aims to restore a balanced dialogue on our comprehension of both beneficial and potentially detrimental outcomes of physical activity that ultimately underscores the imperative of well-informed decision-making and tailored exercise regimens in the realm of posttransplant care.

Lung Ultrasound as a Promising Diagnostic Tool for Primary Graft Dysfunction after Lung Transplantation

PURPOSE

The aim of the study was to evaluate whether the quantification of B-lines via lung ultrasound after lung transplantation is feasible and correlates with the diagnosis of primary graft dysfunction.

METHODS

Following lung transplantation, patients underwent daily lung ultrasound on postoperative days 1-3. B-lines were quantified by an ultrasound score based on the number of single and confluent B-lines per intercostal space, using a four-region protocol. The ultrasound score was correlated with the diagnosis of primary graft dysfunction. Furthermore, correlation analyses and receiver operating characteristics analyses taking into account ultrasound score, chest radiographs, and PaO2/FiO2 ratio were performed.

RESULTS

A total of 32 patients (91 ultrasound measurements) were included, whereby 10 were diagnosed with primary graft dysfunction. The median B-line score was 5 [IQR: 4, 8]. There was a significant correlation between B-line score and the diagnosis of primary graft dysfunction (r = 0.59, p < 0.001). A significant correlation could also be seen between chest X-rays and primary graft dysfunction (r = 0.34, p = 0.008), but the B-line score showed superiority over chest X-rays with respect to diagnosing primary graft dysfunction in the receiver operating characteristics curves with an area under the curve value of 0.921 versus 0.708. There was a significant negative correlation between B-line score and PaO2/FiO2 ratio (r = -0.41, p < 0.001), but not between chest X-rays and PaO2/FiO2 ratio (r = -0.14, p = 0.279).

CONCLUSION

The appearance of B-lines correlated well with primary graft dysfunction and outperformed chest radiographs.

Development and validation of a nomogram model to predict primary graft dysfunction in patients after lung transplantation based on the clinical factors

BACKGROUND

Primary graft dysfunction (PGD), a significant complication that can affect patients' prognosis and quality of life, develops within 72 h post lung transplantation (LTx). Early detection and prevention of PGD should be given special consideration. The purpose of this study was to create a clinical prediction model to forecast the occurrence of PGD.

METHODS

We collected information on 622 LTx patients from Wuxi People's Hospital from 2016 to 2020 and used the data to construct the prediction model. Information on 224 patients from 2021 to June 2022 was used for external validation. We used LASSO regression for variable screening. A nomogram was developed for model presentation. Distinctness, fit, and calibration were used to evaluate the performance of the model.

RESULTS

Subjects with respiratory failure, who received fresh frozen plasma, donor age, donor gender, donor mechanism of death, donor smoking, donor ventilator use time, and donor PaO 2/FiO 2 ratio were independent predictor variables for the occurrence of PGD. The area under the curve of the nomogram was .779. The Hosmer-Lemeshow test showed a good model fit (P = .158). The calibration curve of the nomogram is fairly close to the ideal diagonal. Moreover, the decision curve analysis revealed a positive net benefit of the model. External validation also confirmed the reliability of the model.

CONCLUSIONS

The nomogram of PGD based on clinical risk factors in postoperative LTx patients was established with high reliability. It provides clinicians and nurses with a new and effective tool for early prediction of PGD and early intervention.

Cardiopulmonary response to high-altitude mountaineering in lung transplant recipients-The Jebel Toubkal experience

OBJECTIVES

Only a small proportion of lung transplant recipients achieve a physical status comparable to healthy individuals in the long term. It is reasonable to hypothesize that the necessary cardiopulmonary adaptation required for strenuous physical exercise may be impaired. Exposure to high altitude provides an optimal platform to study the physiological cardiopulmonary adaptation in lung transplant recipients under aerobic conditions. To gain a deeper understanding, 14 healthy lung transplant recipients and healthcare professionals climbed the highest peak in North Africa (Mount Jebel Toubkal; 4167 m) in September 2019.

METHODS

Monitoring included daily assessment of vital signs, repeated transthoracic echocardiography, pulmonary function tests, and capillary blood sampling throughout the expedition.

RESULTS

Eleven out of fourteen lung transplant recipients reached the summit. All recipients showed a stable lung function and vital parameters and physiological adaptation of blood gases. Similar results were found in healthy controls. Lung transplant recipients showed worse results in the 6-minute walk test at low and high altitude compared to controls (day 1: 662 m vs. 725 m, p < 0.001, day 5: 656 m vs. 700 m, p = 0.033) and a lack of contractile adaptation of right ventricular function with increasing altitude as measured by tricuspid plane systolic excursion on echocardiography (day 2: 22 mm vs. 24 mm, p = 0.202, day 5: 23 mm vs. 26 mm, p = 0.035).

CONCLUSIONS

Strenuous exercise in healthy lung transplant recipients is safe. However, the poorer cardiopulmonary performance in the 6-minute walk test and the lack of right ventricular cardiac adaptation may indicate underlying autonomic dysregulation.

Lung Ultrasound to Phenotype Chronic Lung Allograft Dysfunction in Lung Transplant Recipients. A Prospective Observational Study

Background: Bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS) are two distinct phenotypes of chronic lung allograft dysfunction (CLAD) in lung transplant (LTx) recipients. Contrary to BOS, RAS can radiologically present with a pleuroparenchymal fibroelastosis (PPFE) pattern. This study investigates lung ultrasound (LUS) to identify potential surrogate markers of PPFE in order to distinguish CLAD phenotype RAS from BOS. Methods: A prospective cohort study performed at a National Lung Transplantation Center during June 2016 to December 2017. Patients were examined with LUS and high-resolution computed tomography of the thorax (HRCT). Results: Twenty-five CLAD patients (72% males, median age of 54 years) were included, corresponding to 19/6 BOS/RAS patients. LUS-identified pleural thickening was more pronounced in RAS vs. BOS patients (5.6 vs. 2.9 mm) compatible with PPFE on HRCT. LUS-identified pleural thickening as an indicator of PPFE in RAS patients’ upper lobes showed a sensitivity of 100% (95% CI; 54–100%), specificity of 100% (95% CI; 82–100%), PPV of 100% (95% CI; 54–100%), and NPV of 100% (95% CI; 82–100%). Conclusion: Apical pleural thickening detected by LUS and compatible with PPFE on HRCT separates RAS from BOS in patients with CLAD. We propose LUS as a supplementary tool for initial CLAD phenotyping.

Optic nerve sheath diameter changes at high altitude and in acute mountain sickness: meta-regression analyses

BACKGROUND/AIMS

To assess changes in optic nerve sheath diameter (ONSD) at high altitude and in acute mountain sickness (AMS).

METHODS

Cochrane Library, EMBASE, Google Scholar and PubMed were searched for articles published from their inception to 31st of July 2020. Outcome measures were mean changes of ONSD at high altitude and difference in ONSD change between subjects with and without AMS. Meta-regressions were conducted to investigate the relation of ONSD change to altitude and time spent at that altitude.

RESULTS

Eight studies with 248 participants comparing ONSD from sea level to high altitude, and five studies with 454 participants comparing subjects with or without AMS, were included. ONSD increased by 0.14 mm per 1000 m after adjustment for time (95% CI: 0.10 to 0.18; p<0.01). Restricted cubic spline regression revealed an almost linear relation between ONSD change and time within 2 days. ONSD was greater in subjects with AMS (mean difference=0.47; 95% CI: 0.14 to 0.80; p=0.01; I²=89.4%).

CONCLUSION

Our analysis shows that ONSD changes correlate with altitude and tend to increase in subjects with AMS. Small study number and high heterogeneity are the limitations of our study. Further large prospective studies are required to verify our findings.

Intraoperative care of elderly patients with COVID-19 undergoing double lung transplantation: Two case reports

BACKGROUND

Lung transplantation is considered an effective method for treating patients with end-stage coronavirus disease 2019 (COVID-19). The nurses play a pivotal role in lung transplantation for COVID-19 patients.

CASE SUMMARY

Two elderly patients were admitted to the emergency department due to cough, and the nucleic acid test was positive. The patients were preliminarily diagnosed with COVID-19. The chest computed tomography scan revealed massive lung consolidation, and the patients did not improve after treatment with antiviral drugs, glucocorticoids, antibiotics, and other drugs. Under the support of pure oxygen in extracorporeal membrane oxygenation, the patients’ oxygen levels were still poor, indicating that they were in the terminal stage of viral pneumonia. The patients underwent double-lung transplantation and received intraoperative care. The extracorporeal membrane oxygenation device was removed within a week of the surgical procedure, and the respiratory circulation of the patients were stabilized.

CONCLUSION

High-quality care for COVID-19 patients undergoing lung transplantation ensures patient safety during operation while protecting the safety of the medical staff.

[Current developments in lung transplantation]

BACKGROUND

Lung transplantation is the established treatment of benign end-stage pulmonary diseases after failure of alternative surgical and medical treatment options. The aim of this paper is to provide an overview of current developments in selected fields of lung transplantation.

METHODS

A selective literature search was conducted.

RESULTS

Lung transplantation in Germany is currently limited by a donor organ shortage. Measures to increase organ donation rates and to optimize the use of available donor organs are required. Ex-vivo lung perfusion, currently mainly used to re-evaluate marginal donor organs, has the potential to increase the available donor pool and to serve as a platform for additional therapies.

CONCLUSIONS

Refinements in organ allocation, perioperative management, immunosuppression, and in the understanding of acute cellular and humoral rejection as well as chronic lung allograft dysfunction contributed to improvements in long-term outcome after lung transplantation.