Lung Ultrasound Guided Fluid Balance Strategy in Patients with Lung Contusion

Lung contusion is caused by blunt chest trauma, explosion injuries or a shock wave associated with penetrating trauma. These injuries damage alveolar capillaries, so blood and other fluids accumulate in the lung tissue. The excess fluid interferes with gas exchange leading to hypoxia To find out whether lung ultrasound as a non-invasive tool can be used to tailor the better fluid balance strategy to achieve higher oxygenation compared to other conventional methods in patients with lung contusion.

The study will evaluate a fluid management protocol for adult patients, based on the daily assessment of B-line score (BLS) using lung ultrasound, compared to usual care. A pre-specified BLS cut-off value of 15 will be used in this study to correct fluid overload After enrolment, patients were randomly assigned to BLS-guided fluid management (active group) or standard care (control group) in a 1:1 ratio, using a computerised random-number generator.

lung ultrasound guided fluid management based on BLS assessment will be conducted within 24 hours of icu admission and daily thereafter until icu discharge or for up to 14 days after randomization which ever comes first In the active group, with every LU examination, patients will be stratified into four classes: no EVLW increase (BLS = 0-4), mild increase (BLS = 5-14), moderate increase (BLS = 15-29), or severe EVLW increase (BLS ≥ 30).

In patients with no or mild EVLW increase (BLS = 0-14), a zero fluid balance (FB) will be targeted if no signs of shock are present. In patients with a moderate or severe increase in EVLW (BLS ≥ 15), a daily negative FB of -250 to -1000 mL will be targeted until BLS drops under 15. To reach daily targeted FB, furosemide-induced diuresis and RRT will be used. Furosemide will be administrated in a stepwise manner considering the previous furosemide dose and the FB achieved. If the targeted FB is achieved from the first day of diuretic administration, the furosemide dose will be maintained. If FB is outside the targeted range, the furosemide dose will be progressively reduced or increased until the goal is achieved. RRT will be used in patients with moderate and severe EVLW increase (BLS ≥ 15) if the targeted FB cannot be reached despite using the maximum furosemide dose of 800 mg/day.

In case of shocked patients with BLS < 15: they will receive fluid boluses and packed RBCs to achieve a Hb of 10 and a MAP of >65 mmHg.

In case of shocked patients with BLS ≥ 15: they will start norepinephrine infusion to reach a MAP of >65 mmHg.

In the control group, fluid management will be guided to maintain an adequate intravascular volume while minimising weight gain. Various parameters will be used to attain this goal based on case-by-case clinical judgment: lung sounds, heart rate, blood pressure, temperature, urine output, FB, lactate, haemoglobin, haematocrit, serum urea, creatinine, sodium, potassium, chloride, and bicarbonate values

Research outcome measures:

1. Primary (main):

Difference in p-f ratio between the two groups to find out the best strategy for fluid balance for best p-f ratio. 2. Secondary (subsidiary):

Duration of ventilation Duration of ICU stay Duration of hospital stay