Sepsis related cerebral dysfunction was underestimated in critical illness setting, and inflammatory response of brain could not be monitored directly and cerebral oximetry offered information of cerebral dysfunction. We had hypothesized cerebral oxygenation responsiveness during passive leg raising could in some way had association in predicting with the outcomes of septic shock.

Research question: Does increased regional cerebral oxygen saturation variation in passive leg raising(PLR) associated with better neurological outcomes of sepsis and septic shock patients?

Specific aims:

1. To stablish an algorithm to assess focal neurological dysfunction through regional cerebral oxygen saturation(rScO2) of sepsis and septic shock patients
2. To assess the safety and gain some experiences evaluate cerebral oxygen in passive leg raising and fluid expansion.
3. To test the correlation of rScO2 variation with neurological complication and prognosis of septic shock patients.

Significance:

1. Sepsis and septic shock were associated with increased risk of mortality, elevated morbidity rates, and neuro-developmental disability.
2. The definition of SEPSIS 3.0, signify qSOFA scores as a bedside prompt that may identify patients with suspected infection who are at greater risk for a poor outcome, It uses three criteria, including altered mentation (Glasgow coma scale<15).
3. Previously, sepsis related cerebral dysfunction was underestimated in critical illness setting, and inflammatory response of brain, such as oxygen deficit of brain tissue could not be monitored directly, thus cerebral oximetry monitoring could be used for the evaluation of cerebral tissue oxygenation in real time, providing indirect information of the brain function during sepsis and septic shock.
4. Length of reduced cerebral oxygen saturation was confirmed associated with worse outcome after major surgery perioperatively. We hypothesized that cerebral oxygen metabolism was degenerated during sepsis and septic shock, and lower cerebral oxygenation would have somewhat correlations with worse outcome of sepsis and septic shock patients.

Study Design： This will be a observational cohort trial. The schematic diagram of the study is as Figure 1. Subjects will be enrolled, and then be followed up. The outcome variables will be recorded. Inclusion criteria were age above 18 either under 80 years, and diagnosed with sepsis, using Sepsis 3.0 criteria.

Whereas exclusion criteria were patients who were under 18 or above 80 years, pregnant, brain dead, severe head trauma, patients who had a difference more than 10% between the 2 probes of cerebral oxygen saturation monitor due to possible unilateral focal pathology, and whose cousins made decision to withdraw from resuscitation.

The baseline parameters of sepsis and septic shock patients are collected: demographic data (age, sex, comorbidities, resources and diagnosis), Acute Physiology and Chronic Health Evaluation (APACHE) II score (on admission and after 24 hours), hemo-dynamic parameters (mean arterial pressure [MAP], heart rate, cardiac index [CI], stroke volume variation, and global end-diastolic index using PICCO Monitor from Pulsion, Germany), serial lactic acid measurements at presentation and after 48 hours, blood gases (arterial and central venous [at presentation and every 8 hours]), and rScO2 (at presentation and every 8 hours). Delirium were diagnosed using CAM-ICU criteria for delirium in ICU.

Inclusion Criteria:

• Age above 18 either under 80 years, and diagnosed with sepsis, using Sepsis 3.0 criteria.

Exclusion Criteria:

• Patients who were under 18 or above 80 years, pregnant, brain dead, severe head trauma, patients who had a difference more than 10% between the 2 probes of cerebral oxygen saturation monitor due to possible unilateral focal pathology, and whose cousins made decision to withdraw from resuscitation.

The baseline parameters of sepsis and septic shock patients are collected