The role of mechanical ventilation in primary graft dysfunction in the postoperative lung transplant recipient: A single center study and literature review

Driving pressure association with mortality in post-lung transplant patients: A prospective observational study

OBJECTIVE

To investigate the association between driving pressure (ΔP) and 90-day mortality in patients following lung transplantation (LTx) in patients who developed primary graft dysfunction (PGD).

METHODS

This prospective, observational study involved consecutive patients who, following LTx, were admitted to our intensive care unit (ICU) from January 2022 to January 2023. Patients were separated into two groups according to ΔP at time of admission (i.e., low, ≤15 cmH2O or high, >15 cmH2O). Postoperative outcomes were compared between groups.

RESULTS

In total, 104 patients were involved in the study, and of these, 69 were included in the low ΔP group and 35 in the high ΔP group. Kaplan-Meier analysis of 90-day mortality showed a statistically significant difference between groups with survival better in the low ΔP group compared with the high ΔP group. According to Cox proportional regression model, the variables independently associated with 90-day mortality were ΔP and pneumonia. Significantly more patients in the high ΔP group than the low ΔP group had PGD grade 3 (PGD3), pneumonia, required tracheostomy, and had prolonged postoperative extracorporeal membrane oxygenation (ECMO) time, postoperative ventilator time, and ICU stay.

CONCLUSIONS

Driving pressure appears to have the ability to predict PGD3 and 90-day mortality of patients following LTx. Further studies are required to confirm our results.

Impact of Early Tracheostomy After Lung Transplantation: A National Analysis

BACKGROUND

Prolonged mechanical ventilation is common among lung transplant recipients, affecting nearly one-third of patients. Tracheostomy has been shown as a beneficial alternative to endotracheal intubation, but delays in tracheostomy tube placement persist. To date, no large-scale study has investigated the effect of tracheostomy timing on posttransplant outcomes.

METHODS

All adults receiving tracheostomy after primary, isolated lung transplantation were identified in the 2016 to 2020 Nationwide Readmissions Database. Early tracheostomy was defined as placement before postoperative day 8 based on exploratory cohort analysis. Multivariable regression was used to evaluate the association of early tracheostomy with in-hospital mortality, select posttransplant complications, and resource utilization.

RESULTS

Of an estimated 11,048 patients undergoing first-time lung transplantation, 1509 required a tracheostomy in the postoperative period, with 783 (51.9%) comprising the early cohort. After entropy balancing and risk adjustment, early tracheostomy placement was associated with reduced odds of death (adjusted odds ratio, 0.59; 95% CI, 0.36-0.97) and posttransplant infection (adjusted odds ratio, 0.54; 95% CI, 0.35-0.82). Further, tracheostomy within 1 week of transplantation was associated with decreased length of stay (β-coefficient, -16.5 days; 95% CI, -25.3 to -7.6 days) and index hospitalization costs (β-coefficient, -$97,600; 95% CI, -$153,000 to -$42,100).

CONCLUSIONS

The present study supports the safety of early tracheostomy among lung transplant recipients and highlights several potential benefits. Among appropriately selected patients, tracheostomy placement before postoperative day 8 may facilitate early discharge, lower costs, and reduced odds of posttransplant infection.

Primary graft dysfunction after lung transplantation

PURPOSE OF REVIEW

Primary graft dysfunction (PGD) is a clinical syndrome occurring within the first 72 h after lung transplantation and is characterized clinically by progressive hypoxemia and radiographically by patchy alveolar infiltrates. Resulting from ischemia-reperfusion injury, PGD represents a complex interplay between donor and recipient immunologic factors, as well as acute inflammation leading to alveolar cell damage. In the long term, chronic inflammation invoked by PGD can contribute to the development of chronic lung allograft dysfunction, an important cause of late mortality after lung transplant.

RECENT FINDINGS

Recent work has aimed to identify risk factors for PGD, focusing on donor, recipient and technical factors both inherent and potentially modifiable. Although no PGD-specific therapy currently exists, supportive care remains paramount and early initiation of ECMO can improve outcomes in select patients. Initial success with ex-vivo lung perfusion platforms has been observed with respect to decreasing PGD risk and increasing lung transplant volume; however, the impact on survival is not well delineated.

SUMMARY

This review will summarize the pathogenesis and clinical features of PGD, as well as highlight treatment strategies and emerging technologies to mitigate PGD risk in patients undergoing lung transplantation.