Ultrasonographic assessment of diaphragmatic function in patients with sepsis

Abstract

Background
Frequently linked to diaphragmatic impairment, sepsis serves as a primary driver of weakness acquired within the intensive care unit (ICU), a condition that can negatively impact both respiratory capacity and overall patient prognosis. To evaluate the integrity of the diaphragm, clinicians increasingly utilize bedside ultrasonography, a diagnostic modality characterized by its non-invasive nature.


Aim of the work
To evaluate diaphragmatic function using ultrasonography in patients with sepsis and to assess its prognostic significance.


Methods
We conducted a prospective observational investigation involving 54 septic patients requiring intensive care. Participants were stratified into two distinct cohorts based on their Sequential Organ Failure Assessment (SOFA) score. Utilizing ultrasonography, we quantified several key parameters of diaphragmatic function: diaphragm thickness, the thickening fraction (TF), and diaphragmatic excursion recorded during both quiet breathing (QB) and deep breathing (DB). Furthermore, we analyzed the ratio of these excursions (EQB/EDB).


Results

In patients exhibiting elevated SOFA scores, a statistically significant decline in both diaphragm thickness fraction (TF) and diaphragmatic excursion was observed (
p
 < 0.001). Conversely, the physical thickness of the diaphragm remained consistent across all cohorts. Strong inverse correlations were identified between SOFA indices and the triad of diaphragmatic excursion, TF, and the EQB/EDB ratio (
p
 < 0.001). Notably, quiet breathing diaphragmatic excursion emerged as the most potent prognostic indicator, showing an AUC of 0.997 (100% sensitivity; 92.1% specificity) for patient mortality and an AUC of 0.983 (100% sensitivity; 86.7% specificity) regarding the requirement for mechanical ventilation support.



Conclusion
Ultrasonographic assessment of diaphragmatic function is a reliable bedside tool for evaluating diaphragmatic function in patients with sepsis. Diaphragmatic excursion, particularly during quiet breathing, is a strong predictor of mortality and need for mechanical ventilation.