Efficacy of Lung and Inferior Vena Cava Sonography for Fluid Optimization

Traumatic brain injury (TBI) is a leading cause of death and disability in trauma patients. As the primary injury cannot be reversed, management strategies must focus on preventing secondary injury by avoiding hypotension and hypoxia and maintaining appropriate cerebral perfusion pressure (CPP), which is a surrogate for cerebral blood flow (CBF). The goal should be euvolemia and avoidance of hypotension. The assessment of a patient's body fluid status is a challenging task for modern clinicians.

The use of Ultrasonography to assess body fluids has numerous advantages. The concept of using lung ultrasound for monitoring the patient is one of the major innovations that emerged from recent studies. Pulmonary congestion may be semiquantiﬁed using lung ultrasound and deciding how the patient tolerates fluid. Inferior vena cava (IVC) sonography and point-of-care ultrasound (POCUS) has become widely used as a tool to help clinicians prescribe ﬂuid therapy. Common POCUS applications that serve as guides to ﬂuid administration rely on assessments of the inferior vena cava to estimate preload and lung ultrasound to identify the early presence of extravascular lung water and avoid ﬂuid over resuscitation In this study we will use the measurements of both lung and IVC together to guide fluid dosage in critically ill patients with TBI. We will also use ONSD as a mirror for intra-cranial pressure (ICP).

The aim of this study is to detect the effectiveness of using IVC and lung ultrasound as bedside tools to ensure euvolemia in patients with traumatic brain injuries

Positive fluid balances have been associated with (angiographic) vasospasm, longer hospital length of stay and poor functional outcomes The assessment of a patient's body fluid status is a challenging task for modern clinicians. Currently, the most accurate method to guide ﬂuid administration decisions uses "dynamic" measures that estimate the change in cardiac output that would occur in response to a ﬂuid bolus. Unfortunately, their use remains limited due to required technical expertise, costly equipment, or applicability in only a subset of patients. Alternatively, point-of-care ultrasound (POCUS) has become widely used as a tool to help clinicians prescribe ﬂuid therapy.

International recommendations suggest that the inferior vena cava (IVC) can be assessed to estimate the pressure in the right atrium of non-ventilated patients because of its collapsibility during inspiration. An IVC diameter of \< 21mm with collapsibility of \> 50% during inspiration suggests normal right atrium pressure (between 0 and 5 mmHg), whereas a diameter of \> 21mm with collapsibility of \< 50% suggests high pressure (between 10 and 20mmHg). The dynamic method of IVC evaluation, based on the variation in its diameter with respiration, enables the assessment of the potential benefit of fluid administration as a function of IVC compliance.

Ultrasonography of optic nerve sheath diameter (ONSD) in TBI patients has been shown to correlate with increased ICP and systemic reviews have supported this observation.

In this study, we will use the measurements of both lung and IVC together to guide fluid dosage in critically ill patients with TBI. We will also use ONSD as a mirror for ICP

The study investigates the effect of using bedside sonography in fluid assessment in a critically ill patient

Eligibility Criteria:
Inclusion Criteria:

* BMI less than 35 kg/m2
* Diagnosed with traumatic brain injury
* Glasgow coma score ≥ 4

Exclusion Criteria:

* Inability to get consent
* Presence of Increased intra-abdominal pressure,
* Presence of acute cor pulmonale
* Presence of severe right ventricular dysfunction.
* Pregnancy
* Patients with known pulmonary conditions that interfere with the interpretation of lung ultrasound like pneumectomy; pulmonary fibrosis; persistent pleural effusion
* Stage 5 chronic kidney disease
* indication for emergency renal replacement therapy (RRT)