Effect of Balanced Saline Solution and Albumin on Volume Expansion in Shock Patients

Inclusion Criteria: 1. Age ≥ 18 years old, gender unlimited 2. Shock requires volume resuscitation: Insufficient tissue perfusion: wet and cold skin, decreased urine volume (\<0.5ml/kg/h), change of consciousness, blood lactate \>2.0mmol/l or vasoactive drugs are required to maintain map\>65mmhg 3. Presence of volume reactivity: (under controlled ventilation) PPV ≥ 15% or passive leg raising test (+) or (under controlled ventilation) IVC variability ≥ 18% or the presence of volume reactivity as judged by clinicians 4. The patient has no obvious restlessness, RASS ≤ 0 5. The legal representative of the subject signs the informed consent form- Exclusion Criteria: 1. Pregnant and lactating women 2. End stage patients 3. BMI ≤ 15 or BMI ≥ 50 4. Contraindication of indwelling central vein catheter and invasive arterial catheter 5. Patients in ECMO and / or IABP therapy 6. Hemorrhagic shock, blood products such as concentrated red blood cells, plasma and platelets will be infused within 1 hour 7. Myocardial infarction, NYHA grade IV 8. Patients with hyperkalemia, hypercalcemia, hypermagnesemia and hypothyroidism 9. Allergic to compound sodium acetate ringer injection or albumin or with known side effects 10. Other factors that may affect the monitoring and evaluation of relevant indicators