ALB and infection: In addition to the aforementioned experimental target dehydration adjustment measures, homogeneous management was adopted for all three groups of patients, including primary disease treatment, anti-infection protocol, airway management, mechanically assisted ventilation strategy, maintenance of fluid volume and electrolyte balance (4.0 mmol/l < potassium < 5.3 mmol/l), drug therapy, administration of colloidal fluid supplement such as albumin (to maintain albumin > 3.5 g/l), and nutritional support.