# P-2127. Early Post-Lung Transplant (LTx) Infections in the Antimicrobial Prophylaxis Era

## TL;DR

This study examines early infections after lung transplants, finding that bacterial pneumonia is most common and that longer intubation and ECMO use increase infection risk.

## Contribution

The study identifies risk factors and outcomes of early post-transplant infections in the antimicrobial prophylaxis era.

## Key findings

- Bacterial infections, especially pneumonia, were most common in the first 30 days after lung transplantation.
- Patients requiring ECMO and longer intubation had increased infection risk.
- Positive donor cultures were not linked to higher recipient infection risk, likely due to a notification system.

## Abstract

Despite widespread antimicrobial prophylaxis, infections remain a common complication after lung transplantation (LTx). This study aimed to identify the occurrence, risk factors, & outcomes of early infections post-LTx.Figure 1A:Infection Free Survival within 90 days after Lung transplantation

Infection Free Survival within 90 days after Lung transplantation

We conducted a retrospective cohort study of adult LTx recipients at Michigan Medicine from 1/2021 to 4/2024. Demographics, surgical details, complications, immunosuppression, preoperative cultures, infections, & deaths within the first 90 days (d) after LTx were collected through chart review by a single reviewer & a second arbitrated unclear infection cases. Per institutional policy, all LTx pt received prophylaxis against surgical & opportunistic infections. A notification system for donor infections/colonization triggered targeted antimicrobials when needed. Fisher’s exact tests & Wilcoxon rank-sum tests analyzed categorical & continuous variables, respectively. Kaplan-Meier (K-M) curves assessed infection-free survival.Figure 1B:Infection Free Survival among lung transplant recipients who required ECMO and those without ECMO

Infection Free Survival among lung transplant recipients who required ECMO and those without ECMO

56 LTx recipients were included, 42 (75%) bilateral & 14 (25%) single LTx. Interstitial lung disease was the most common LTx indication (60.7%)(Table). Postoperative infections occurred in 29 pt (51.8%), 18 pt had 1 infection, 6 had 2, & 5 had≥3. Bacterial infections were most common (34; 66.7%), followed by viral (4; 7.8%) & fungal infections (3; 5.8%). Most common site of infection were the lungs [pneumonia (32), tracheobronchitis (6), empyema (4) & lung abscess (1)] & the surgical site (2). Increased infection risk was associated with longer intubation (6.4 vs. 2.3 d; p=0.003). Positive donor culture/infection was associated with a lower risk of infection given all pt without infection had positive donor cultures. Most infections occurred < 2 weeks after LTx, & more frequently among pt on ECMO (p=0.02) (Figure 1A&B). 7 pt died within 90 d after LTx, infection contributed to death in 2 pt.

Bacterial infections, mainly pneumonia, were most common within 30 d after LTx, ECMO & longer intubation increased the risk of infection. These findings emphasize the need for ongoing evaluation & adjustment of infection prevention strategies, including efforts to reduce invasive procedures after LTx . Positive donor cultures did not increase the risk for infection, likely due to our ongoing notification system.

Marisa H. Miceli, MD, F2G: PI in clinical trial|GSK: PI clinical trial|Pulmocide: PI in clinical trial|Scynexis: Advisor/Consultant