Fig. 5

Clinical algorithm for EEOT and mini-FC application in the ICU and the OR. In the OR, FHTs can be added to the dynamic indexes evaluation, considering the gray zone reported in the literature [21]. When PPV or SVV values range within the gray zone, we suggest the use of the EEOT, as the first step. A clear positive response (SV increase > 5%) suggests fluid responsiveness, whereas a negative/uncertain response could be further investigated by the consequent use of the mini-FC, as indicated. In critically ill patients, the need of FC administration is often evaluated combining different signs and measurements [58]. In this context, the EEOT (in patient undergoing controlled mechanical ventilation) and the mini-FC (in patients retaining to some extent a spontaneous breathing effort) can be useful when the PLR is unsuitable.*We suggest a FC of 4 ml/kg [55] over 10 min. **Intra-abdominal hypertension; uncontrolled pain, cough, discomfort, and awakening; hip/leg fractures; uncontrolled intracranial hypertension. ICU, intensive care unit; OR, operating room; FC, fluid challenge; PLR, passive leg raising; CMV, controlled mechanical ventilation; SB, spontaneously breathing patients; AMV, assisted mechanical ventilation; PPV, pulse pressure variation; SVV, stroke volume variation; EEOT, end-expiratory occlusion test; SV, stroke volume