Prospective Study Evaluate the Timing of Empirical Treatment for Carbapenem-resistant Bacterials (CROEAT Study)

Inclusion Criteria: * Patients with hematological malignancies receiving hospital treatment such as chemotherapy/immunotherapy/hematopoietic stem cell transplantation; * Those with a recent history of CRO colonization or who have been screened for CRO once a week continuously since admission; * Patients assessed by the clinician as being at high risk for CRO infection and requiring intravenous antibiotics covering CRO must meet the following conditions: 1. Positive active screening for CRO or past CRO infection or local prevalence of CRO (e.g.,CRO detection rate\>20% among recently hospitalized patients); 2. Presence of fever or other possible signs and symptoms of infection; 3. Neutropenia(ANC\<0.1×10\^9/L)expected to last for ≥7 days,and having any of the following: * Gastrointestinal mucositis/peri-anal infection/intestinal obstruction; * Shock or severe sepsis; * Respiratory failure:deoxygenated PaO2\<60 mmHg or requiring mechanical ventilation; * Disseminated intravascular coagulation; * Altered mental status or psychiatric abnormalities; * Congestive heart failure requiring treatment; * Arrhythmia requiring treatment; * Recurrence of fever shortly after cessation of or during empirical treatment with carbapenems (≤7 days). * The patient or their legal guardian has signed the informed consent form. Exclusion Criteria: * Pregnant or breastfeeding women; * Individuals who are expected to die within 14 days of hospitalization or have an expected hospital stay of less than 7 days; * Any conditions that the investigator believes may increase the risk to the patient; * Severe psychological or psychiatric disorders with poor estimated compliance; * The presence of any other conditions that the investigator deems unsuitable for participation in this study.