Prediction models of methicillin sensitive Staphylococcus aureus ventilator associated pneumonia relapse in trauma and brain injury patients: A retrospective analysis

Risk factors of second ventilator-associated pneumonia in trauma patients: a retrospective cohort study

BACKGROUND

Ventilator acquired pneumonia (VAP) is a frequent and serious complication in ICU. Second episodes of VAP are common in trauma patients and may be related to severity of underlying conditions, treatment or bacterial factors of the first VAP. The aim of this study was to identify risk factors of second VAP episodes in trauma injured patients (defined as the development of a new pulmonary infection during or remotely following the first episode).

DESIGN

This is a single-center, retrospective cohort study of trauma injured patients who underwent a first episode of VAP between January 1, 2013 and December 31, 2020 at Beaujon Hospital.

RESULTS

A total of 533 patients with a first episode of VAP were analyzed, mostly with head and/or thoracic traumatic injury. A second episode of VAP occurred in one hundred sixty-seven patients (31.3%). The main risk factors found was the degree of hypoxemia at the time of the first episode [PaO2/FiO2 ratio 100-200, OR 3.12 (1.77-5.69); < 100, OR 5.80 (2.70-12.8)] and severe traumatic brain injury characterized by an initial GCS ≤ 8 [OR 1.65 (1.01-2.74)].

CONCLUSION

Depth of hypoxemia during the first VAP episode and severity of the initial brain injury are the main risk factors for VAP second episode in trauma injured patients.

Cholesterol Microdomain Enhances the Biofilm Eradication of Antibiotic Liposomes

Resistance and tolerance of biofilms to antibiotics is the greatest challenge in the treatment of bacterial infections. Therefore, developing an effective strategy against biofilms is a top priority. Liposomes are widely used as antibiotic drug carriers; however, common liposomes lack affinity for biofilms. Herein, biofilm-targeted antibiotic liposomes are created by simply adjusting their cholesterol content. The tailored liposomes exhibit significantly enhanced bacterial inhibition and biofilm eradication effects that are positively correlated with the cholesterol content of liposomes. The experiments further demonstrate that this enhanced effect can be ascribed to the effective drug release through the pores, which are formed by the combination of cholesterol microdomains in liposomal lipid bilayers with membrane-damaged toxins in biofilms. Consequently, liposome encapsulation with a high cholesterol concentration improves noticeably the pharmacodynamics and biocompatibility of antibiotics after pulmonary administration. This work may provide a new direction for the development of antibiofilm formulations that can be widely used for the treatment of infections caused by bacterial biofilms.