Fluid resuscitation with colloids of different molecular weight in septic shock

Objective

The aim of this study was to investigate the effect of fluid resuscitation with 4% modified fluid gelatine (GEL) versus 6% hydroxyethyl starch (HES) on extravascular lung water (EVLW) and oxygenation in patients with septic shock and acute lung injury (ALI).

Design

A prospective randomized double-blinded clinicial trial.

Setting

A 20-bed intensive care unit in a university hospital.

Patients

Thirty hypovolemic patients (intrathoracic blood volume index [ITBVI] < 850 ml/m²) in septic shock with ALI were randomized into HES and GEL groups (15 patients each).

Interventions

For fluid resuscitation 250 ml/15 min boluses (maximum 1000 ml) were given until the end point of ITBVI > 900 ml/m² was reached. Repeated haemodynamic measurements were performed at baseline (tb), at the end point (tep) then at 30 and 60 min after the end point was reached (t30, t60). The cardiac output, stroke volume, EVLW, and oxygen delivery was determined at each assessment point. For statistical analysis two-way ANOVA was used.

Measurements and results

The ITBVI, cardiac index, stroke volume index, and oxygen delivery index increased significantly at tep and remained elevated for t30 and t60, but there was no significant difference between the two groups. EVLW, although moderately elevated, remained unchanged, and there was no significant difference between the groups (HES: tb, 8 ± 6 ml/kg; t60, 8 ± 6 ml/kg; GEL: tb, 8 ± 3 ml/kg; t60, 8 ± 3 ml/kg). The PaO₂/FiO₂ did not change significantly over time or between groups (HES: tb, 207 ± 114 mmHg; t60, 189 ± 78 mmHg; GEL: tb, 182 ± 85 mmHg; t60, 182 ± 85 mmHg). The increase in the ITBVI by 100 ml/s of infusion was similar in both groups (HES. 26 ± 19 ml/m² vs GEL. 30 ± 19 ml/m²).

Conclusion

The results of this study indicate that both HES and GEL infusions have similar haemodynamic effects in septic shock, without increasing the EVLW or worsening oxygenation.