Patient characteristics and outcome of end-stage lung diseases referred for lung transplantation in North India

The PROgnostic ModEl for chronic lung disease (PRO-MEL): development and temporal validation

BACKGROUND

Patients with chronic lung diseases (CLDs), defined as progressive and life-limiting respiratory conditions, experience a heavy symptom burden as the conditions become more advanced, but palliative referral rates are low and late. Prognostic tools can help clinicians identify CLD patients at high risk of deterioration for needs assessments and referral to palliative care. As current prognostic tools may not generalize well across all CLD conditions, we aim to develop and validate a general model to predict one-year mortality in patients presenting with any CLD.

METHODS

A retrospective cohort study of patients with a CLD diagnosis at a public hospital from July 2016 to October 2017 was conducted. The outcome of interest was all-cause mortality within one-year of diagnosis. Potential prognostic factors were identified from reviews of prognostic studies in CLD, and data was extracted from electronic medical records. Missing data was imputed using multiple imputation by chained equations. Logistic regression models were developed using variable selection methods and validated in patients seen from January 2018 to December 2019. Discriminative ability, calibration and clinical usefulness of the model was assessed. Model coefficients and performance were pooled across all imputed datasets and reported.

RESULTS

Of the 1000 patients, 122 (12.2%) died within one year. Patients had chronic obstructive pulmonary disease or emphysema (55%), bronchiectasis (38%), interstitial lung diseases (12%), or multiple diagnoses (6%). The model selected through forward stepwise variable selection had the highest AUC (0.77 (0.72-0.82)) and consisted of ten prognostic factors. The model AUC for the validation cohort was 0.75 (0.70, 0.81), and the calibration intercept and slope were - 0.14 (-0.54, 0.26) and 0.74 (0.53, 0.95) respectively. Classifying patients with a predicted risk of death exceeding 0.30 as high risk, the model would correctly identify 3 out 10 decedents and 9 of 10 survivors.

CONCLUSIONS

We developed and validated a prognostic model for one-year mortality in patients with CLD using routinely available administrative data. The model will support clinicians in identifying patients across various CLD etiologies who are at risk of deterioration for a basic palliative care assessment to identify unmet needs and trigger an early referral to palliative medicine.

TRIAL REGISTRATION

Not applicable (retrospective study).

Profile of patients referred for lung transplant and their transplant-free survival

INTRODUCTION

Lung transplant (LTx) is a potential treatment option for all patients with chronic, end-stage respiratory disease, who are refractory to optimal medical therapy or where no medical therapy exists. In India, LTx is still in its evolving stages and published literature is sparse. The current study was carried out to study the selection criteria for lung transplant and to evaluate the clinical and socio-economic profile of patients referred for the same at a tertiary health care facility.

METHODS

The study was a descriptive, prospective, observational study. All adults referred for lung transplant were evaluated for clinical and laboratory profiles. All enrolled patients were assessed for presence of referral criteria, listing criteria, contraindications, and willingness for lung transplant. These patients were followed up for 2 years for transplant-free survival, and the Cox proportional hazards model was used to determine independent predictors of all-cause mortality.

RESULTS

A total of 103 were included in study. The most common diagnosis was interstitial lung disease (57.2%), followed by bronchiectasis (17.5%) and COPD (13.6%). Most patients were referred for LTx at an advanced stage as 90% met listing criteria. Fifty-four (52.4%) patients had an absolute or relative contraindication to transplant; however, the majority of those contraindications were modifiable. Patients with a lower socio-economic status were less likely to be willing for LTx. The median survival was 757 days. A 6-minute walk distance (6MWD) lesser than 250 m was found to be an independent predictor of mortality.

CONCLUSION

Making patients aware about lung transplant early in their treatment may give them sufficient time to come to terms with their disease and understand the risk and benefits associated. Efforts should be focused on screening and early treatment of reversible contraindications for the eligible patients. Patients with 6MWD < 250 m are at increased risk of mortality.

Silica-associated lung disease in developing countries

PURPOSE OF REVIEW

There is a considerable burden of silica-associated lung diseases in the developing world. This review summarizes the epidemiology of these diseases, especially silicosis and silico-tuberculosis, mitigative efforts and treatment, especially in the context of developing countries.

RECENT FINDINGS

In 2017, the highest incidence of silicosis was in China, India and Brazil among the developing countries. The prevalence of silicosis amongst exposed workers may vary from 4 to 55%; there is a risk of underestimation because of the 'healthy worker effect'. The permissible exposure limit for respirable silica adopted by governments in developing countries remains higher than the proposed 0.025 mg/m3. Silica exposure in informal or unorganized industries is challenging, as it falls outside statutory controls. Recent efforts on regulation and compensation by various governments in developing countries are encouraging but need proper implementation on the ground. Biomarkers such as club cell protein 16 and imaging methods such as computed tomography may offer earlier and easier detection of silicosis. Advanced silicosis remains incurable; novel treatments such as antifibrotics agents may be potentially effective.

SUMMARY

Silica-associated lung diseases are prevalent in developing countries. Efforts directed at preventing or minimizing exposure to respirable crystalline silica are required for mitigation.

Lung Transplantation in India: a Brief Review, Landmarks, Indian Scenario, and our Experience

Lung transplantation is gaining widespread acceptance as the preferred therapeutic option for selected cases of end-stage lung disease in India. The indications of lung transplantation are increasing, with better post-operative survival, including the COVID affected lung, if we choose our patients well. The national acceptance of expanded criteria in lung donation, streamlining of the process of lung transplantation by governmental, and non-governmental organizations and significant increase in the number of organ donations in India have strengthened the lung transplantation program within the country. Through this article, we describe a brief history, the process, and our experience of lung transplantation since we started our program in 2017 until date.

The evolution of lung transplantation in India and the current scenario

Lung transplantation has come of age in India. This article aims to trace the evolution of lung transplantation in India from its humble beginnings in 1999 to the current scenario spanning a period of 22 years. Right from the passing of the Act legalising deceased organ transplantation, its amendments and rules—to the development of transplant regulatory bodies—both at national and state levels, the journey thus far has been chronicled. Description of the initial cases at sporadic centres which has now proliferated to many centres now across many states has been elaborated on. The impacts on evolution of lung transplantation by the governmental transplant organisations, non-governmental organisations, and the medical professional societies are described. Publications related to lung transplantation from India are mentioned. Situations specific to India, current scenario of lung transplantation, and future directions are discussed. A brief mention of our experience with lung transplantation has also been made.

Underutilization of potential donors for lung transplantation at a tertiary care center in North India

Objective:

Lung transplantation is infrequently performed in India due to several constraints, and whether the poor lung transplantation rates in India are due to a lack of eligible lung donors is unclear. In this study, we explored the availability of donors for lung transplantation.

Materials and Methods:

This was a retrospective analysis of all brain-dead participants who underwent assessment of eligibility for lung donation between August 2015 and June 2018. All participants underwent a detailed clinical evaluation that included history, physical examination, arterial blood gas analysis, chest radiograph, and bronchoscopy. The final eligibility for lung donation was assessed using the existing “ideal” criteria and the less stringent “extended” criteria.

Results:

A total of 55 brain-dead participants (41 [74.5%] males) were assessed for eligibility for lung donation. The mean (standard deviation [SD]) age of the participants was 38.4 (17.2) years. The mean (SD) duration of prior invasive mechanical ventilation at the time of assessment was 4 (3.1) days, with a mean (SD) partial pressure of arterial oxygen: inspired oxygen fraction ratio (PaO₂:FiO₂) of 326.6 (153.5). The proportion of participants who were found suitable for lung donation was 16 (29.1%) and 35 (63.6%) on employing the ideal and the extended criteria, respectively. Inadequate oxygenation status, abnormal chest radiograph, and sepsis were the most common reasons for excluding participants using either criteria. Despite the availability of adequate lung donors, only one lung transplantation could be performed.

Conclusion:

Even with the most stringent criteria for lung assessment, nearly one-third of the brain-dead participants had lungs suitable for lung transplantation. Lack of eligible lung donors is not a reason for the poor lung transplantation rates in India.