Clinical impact of metagenomic next-generation sequencing on pathogen detection and outcomes in non-immunocompromised patients with severe pneumonia supported by veno-venous extracorporeal membrane oxygenation.

BACKGROUND: Timely pathogen identification is crucial for guiding antimicrobial therapy in severe pneumonia requiring veno-venous extracorporeal membrane oxygenation (vv-ECMO). Compared with slow and often insensitive conventional culture, metagenomic next-generation sequencing (mNGS) enables more rapid and comprehensive pathogen detection and may improve clinical management. This study aimed to evaluate the clinical impact of mNGS compared with conventional culture in non-immunocompromised patients undergoing vv-ECMO for severe pneumonia. METHODS: The retrospective study explored non-immunocompromised patients with severe pneumonia who received vv-ECMO support between January 2017 and June 2023. A total of 151 patients were categorized into the mNGS group and the non-mNGS group, based on whether they underwent mNGS testing. Furthermore, they were stratified into the Death group and Survive group according to their survival status at day 30. Demographics, laboratory test results, pathogens, antibiotic treatment, and clinical outcomes data were recorded and analyzed. RESULTS: The positivity rate identified through the mNGS method (73.3%) was notably higher than that obtained through conventional culture (43.1%, P < 0.001). mNGS exhibited superior capabilities in identifying co-infections compared to conventional culture (70.9% vs. 30.1%, P < 0.001). Furthermore, the 30-day mortality rate within the mNGS group demonstrated a significant decrease compared to the no-mNGS group (P = 0.045). Additionally, Kaplan-Meier survival analysis yielded comparable outcomes in both groups (P = 0.035). Factors protecting against adverse outcomes encompassed prolonged hospital stay time, extended ECMO duration, lower Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, successful ECMO weaning, and the application of mNGS. Antibiotic adjustments were implemented in 29 patients (58%) in the mNGS group and 39 patients (38.6%) in the no-mNGS group, with a markedly higher adjustment ratio in the former, demonstrating statistical significance (P = 0.024). Following adjustment of the treatment plan, the mNGS group demonstrated reduced APACHE II scores compared to the no-mNGS group after 5 days of treatment (P = 0.006). CONCLUSIONS: The mNGS technique, with its superior pathogen detection rate, emerges as a promising tool for microbiological diagnosis and antibiotic management, ultimately contributing to enhanced patient outcomes.