Microbiologic surveillance through subglottic secretion cultures during invasive mechanical ventilation: a...

Area of Science:

• Critical Care Medicine
• Infectious Diseases
• Microbiology

Background:

• Microbiological surveillance is crucial for managing patients on invasive mechanical ventilation.
• The utility of subglottic secretion (SS) cultures for predicting pathogens in endotracheal aspirates (ETA) and bronchoalveolar lavage (BAL) remains unclear.

Purpose of the Study:

• To prospectively assess the predictive value of subglottic secretion (SS) cultures against endotracheal aspirate (ETA) and bronchoalveolar lavage (BAL) isolates.
• To evaluate SS cultures for microbiological surveillance in patients undergoing invasive mechanical ventilation.

Main Methods:

• Prospective study involving 109 patients on mechanical ventilation for ≥48 hours.
• Twice-weekly surveillance cultures of SS and ETA were performed.
• Blind BAL was conducted for clinically suspected pneumonia.

Main Results:

• Subglottic secretion (SS) and endotracheal aspirate (ETA) cultures demonstrated 81% overall concordance.
• SS cultures showed 84% sensitivity and 74% specificity for predicting ETA isolates.
• Compared to BAL, SS cultures had 68% sensitivity and 63% specificity, comparable to ETA.

Conclusions:

• Subglottic secretion (SS) cultures exhibit significant accuracy in identifying endotracheal aspirate (ETA) pathogens, with high sensitivity.
• SS cultures may be a viable alternative to ETA for predicting outcomes in ventilator-associated pneumonia, showing non-inferiority to ETA in anticipating BAL results.