[Effect of fluid resuscitation on extravascular lung water in early stage of septic shock].

OBJECTIVE

To determine the effect of fluid resuscitation on extravascular lung water (EVLW) in early stage of septic shock.

METHODS

Twenty septic shock patients with hypovolemia [intrathoracic blood volume index (ITBVI)<750 ml/m(2)] were randomly divided into two groups: EVLW index (EVLWI)< or =7 ml/kg group (n=8) and EVLWI >7 ml/kg group (n=12) according to the EVLWI value determined on admission day. Fluid resuscitation was given at 250 ml in bolus every 15 minutes until the end point of ITBVI>850 ml/m(2) was reached. Repeated haemodynamic measurements were done at baseline (Tb), at the end point (T0) then at 1 hour (T1), 2 hours (T2) and 4 hours (T4) after the end point of resuscitation was reached. EVLWI, pulmonary vascular permeability index (PVPI), ITBVI, global end-diastolic volume index (GEDVI), cardiac index (CI), stroke index (SI), central venous pressure (CVP) and oxygenation index (PaO(2)/FiO(2)) were determined at each time point, and the outcomes of these patients after 28 days were recorded.

RESULTS

(1)ITBVI, GEDVI, CI, SI, CVP were increased significantly at T0 and remained elevated at T1 and T2 in two groups (P<0.05 or P<0.01), but declined at T4 with no significant difference compared with those at Tb (all P>0.05). There were also no significant differences at the same period of time between the two groups (all P>0.05). (2)No changes in PaO(2)/FiO(2) and EVLWI were found over time in two groups compared with those at Tb (all P>0.05), but the PaO(2)/FiO(2) in EVLWI>7 ml/kg group were all lower than that of EVLWI< or =7 ml/kg group at any time point (all P<0.05). (3)EVLWI was not significantly correlated with ITBVI, GEDVI, CI, SI, CVP but negatively correlated with PaO2/FiO2 (r=-0.765, P<0.01), and positively correlated with PVPI (r=0.678, P<0.01). (4)Six patients died within 28 days. EVLWI of the dead patients were prominently higher at Tb and T4 than those of survived patients (both P<0.01), but the EVLWI gap (DeltaEVLWI) had no difference before and after resuscitation (P>0.05).

CONCLUSION

Fluid resuscitation in early stage of septic shock can improve ITBVI, GEDVI, CI, SI, CVP, with neither increased EVLWI nor worsened oxygenation. EVLWI has significantly negative correlation with PaO(2)/FiO(2) but not with haemodynamics. The increase in PVPI is responsible for the elevation of EVLWI. The patient's outcome is significantly correlated with the value of EVLWI.