Résumé
The number of admissions of immunocompromised patients to critical care units is increasing. The main reason for admission is acute respiratory failure, with infectious causes predominating. Early and appropriate antibiotic therapy improves prognosis, with rapid diagnostic techniques such as multiplex PCR playing a key role. In contrast to the immunocompetent patient, few data are available to date on the immunocompromised patient. In this retrospective, single-center study, we analyzed data from immunocompromised patients admitted for acute respiratory failure requiring invasive ventilation in the Medical Intensive Care Unit of Montpellier University Hospital. The primary endpoint was the evaluation of the diagnostic performance of BFPP multiplex PCR compared with conventional culture. The secondary endpoint was the therapeutic impact of the results of BFPP multiplex PCR. One hundred and fourteen patients were included, with immunosuppression mainly of a hematological (35.1%) and oncological (35.1%) nature. The multiplex PCR positivity rate was 36.8%, with the majority identifying enterobacteria (51%) and a median turnaround time of between 2h30 and 4h. Comparison of rapid techniques with cultures showed sensitivity of 89%, specificity of 83%, PPV of 52% and NPV of 98%. Concordance between the two techniques was complete in 84.2% of cases. PCR enabled antibiotic therapy to be modified in 17.5% of cases, mainly de-escalation. In conclusion, the use of BFPP multiplex PCR in the diagnosis of pneumopathy in immunocompromised patients shortens the time required to obtain results, and is particularly effective to eliminate the presence of multi-resistant germs. Bacteria detected in culture and not included in the BFPP multiplex PCR spectrum were mostly bacteria of low pathogenicity or sensitive to the antibiotics usually prescribed. The multiplex PCR technique could therefore reduce exposure to broad-spectrum antibiotics in this population already highly exposed to antibiotics.