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.