Fibrinogen-to-Albumin Ratio as a Predictor of Acute Respiratory Distress Syndrome in Traumatic Brain Injury

Traumatic brain injury is a major cause of morbidity and mortality worldwide and represents a significant challenge in intensive care units. In addition to the primary neurological damage, patients with moderate to severe traumatic brain injury frequently develop systemic inflammatory responses that may lead to secondary organ dysfunction. These systemic effects are mediated by activation of inflammatory cytokines, endothelial injury, and coagulation abnormalities.

Acute respiratory distress syndrome is a common and serious complication in patients with traumatic brain injury, even in the absence of direct chest trauma. Epidemiological studies indicate that acute respiratory distress syndrome develops in approximately 19-30% of severe traumatic brain injury patients, typically within the first week after injury, with a median time to onset of around 3 days.

The fibrinogen-to-albumin ratio has recently emerged as a novel biomarker reflecting both inflammatory and nutritional status. Fibrinogen is a positive acute-phase reactant that increases in response to inflammation and tissue injury, while albumin is a negative acute-phase protein that decreases during systemic inflammatory states. Previous studies have demonstrated that fibrinogen-to-albumin ratio is altered in patients with traumatic brain injury and correlates with injury severity and clinical outcomes.

Given that the same inflammatory and coagulation pathways influencing fibrinogen-to-albumin ratio in traumatic brain injury also play a central role in the development of acute respiratory distress syndrome, it is biologically plausible that early fibrinogen-to-albumin ratio measurements may predict acute respiratory distress syndrome occurrence in this patient population. However, the predictive value of fibrinogen-to-albumin ratio for acute respiratory distress syndrome in patients with traumatic brain injury has not yet been adequately investigated.

Inclusion criteria

• Patients ≥ 18 years admitted to the ICU with traumatic Brain Injury
• Admission to the ICU within 24 hours of injury.
• Patients will be expected to remain under hospital care for follow-up
• Availability of fibrinogen and albumin measurements within the first 24 hours of ICU admission.
• Informed consent will be obtained from a legally authorized representative.

Exclusion criteria

• Preexisting advanced chronic liver disease, nephrotic syndrome, or protein-losing enteropathy.
• Pre-existing ARDS on admission.
• Recipient of albumin, fibrinogen concentrate, or cryoprecipitate before admission sampling.
• Use of anticoagulant or fibrinolytic therapy before admission.
• Active malignancy or severe systemic infection at admission.
• Direct sever lung injury
• Pregnancy
• Refusal of consent