Instruct to collect blood culture samples. When the patient's body temperature is higher than 38℃ or lower than 36℃, the patient chills, and the routine white blood cell count is greater than 10× 109 /L, especially when there are immature or "nuclear left shift" rod-shaped white blood cells, the granulocytes decrease and mature. Polynuclear leukocytes

Is there the best time to collect blood culture samples?

Blood culture specimens have the best collection time. As far as possible, blood should be collected at the beginning of the patient's chills and 30-60 minutes before the peak of high fever. In addition, blood should be collected before patients receive antibiotic treatment. However, if the patient has been treated with antibacterial drugs, blood should be drawn before the next medication.

Why use aerobic and anaerobic bottles and collect two sets?

Simultaneous sampling of aerobic and anaerobic bottles is helpful to improve the positive rate. Bacteria include aerobic bacteria, anaerobic bacteria and facultative anaerobic bacteria. Facultative anaerobic bacteria can grow in aerobic or anaerobic environment, but they grow better in anaerobic environment, and most pathogens belong to this category. Therefore, it is suggested that each group of blood cultures should be inoculated in both aerobic and anaerobic bottles at the same time, which is beneficial to the detection of micro-aerobic and anaerobic bacteria. But if you can't reach the recommended blood collection, you must first reach the aerobic bottle. Adult patients need to draw 20ml of blood from a group of blood culture specimens, with aerobic bottles and anaerobic bottles each 10ml. The detection sensitivity of one group of specimens was 73.2%, and that of two groups of specimens was 93.9%. It can be seen that collecting two groups of specimens can obviously improve the detection sensitivity, so it is necessary to take two groups of specimens. It is worth noting that if two groups of specimens are taken, blood should be collected at two puncture points respectively.

How to standardize the collection of blood culture specimens?

Step 1: Hand hygiene. Carry out hand hygiene with soap liquid and running water or alcohol-containing quick hand disinfectant.

Step 2: Disinfect the bottle stopper. Sterilize the culture bottle stopper with alcohol gauze and let it dry fully.

Step 3: Disinfect the skin. The diameter of the mirror body is not less than 5cm, and it shall not be touched by hand after disinfection.

① Disinfect with 70%-80% ethanol for at least 30 seconds.

② Disinfect with 1%-2% tincture of iodine for 30 seconds or 10% iodophor for 60 seconds.

③ Deiodination with 70%-80% ethanol.

Note: Patients who are allergic to iodine should be disinfected twice with 70%-80% ethanol for 3 minutes each time, and blood samples should be collected after the ethanol is evaporated and dried.

Step 4: draw blood. Do not change the needle after blood collection, and directly inject it into the blood culture bottle. If the blood volume is sufficient, inject the anaerobic bottle first and then the aerobic bottle; If the blood volume is insufficient, inject the oxygen bottle first, and then inject the rest into the anaerobic bottle, because fungi, Pseudomonas aeruginosa and Stenotrophomonas grow in the oxygen bottle.

Step 5: Mix well. After the blood culture specimen is inoculated into the culture bottle, gently invert it and mix it evenly to prevent blood coagulation, and do not shake it forcibly. Mark the location and time of blood collection on each culture bottle, indicating whether it is catheter blood or peripheral blood.

Step 6: Select the opposite puncture site in the same way and collect the second group of specimens.

Part VII: Inspection. Blood culture specimens should be sent to the laboratory as soon as possible, and any delay will delay or prevent the growth of the detected bacteria.

Note: Blood samples should be taken from veins, not from venous catheters or venous indwelling ports. If blood is taken from catheter facilities, do not discard the initial blood and do not wash it with anticoagulant. Blood must be taken from veins at the same time for comparison and explanation. It is not recommended to use vacuum blood collection needle (butterfly needle) to put venous blood directly into the bottle. Replacing needles with bottles is not recommended. Blood culture bottles should not be stored in refrigerators and freezers.

Unused blood culture bottles should be kept at room temperature and should not be refrigerated or frozen after inoculation.

The collection of blood culture specimens requires strict aseptic operation, but there may still be inevitable pollution in the process of collection, inspection and inoculation. Will there be some contaminated bacteria?

The following bacteria are positive in many blood cultures and can be regarded as contaminated bacteria, including coagulase-negative staphylococci, Corynebacterium, Micrococcus, Propionibacterium and Bacillus. If blood culture is positive for many times, it may be a conditional pathogen and needs to be combined with clinical analysis.

General suggestions on collecting blood culture specimens of adults and adolescents;

1. Before treatment, patients with bloodstream infection, meningitis, osteomyelitis, arthritis and pneumonia were given 2 or 3 groups of blood from different parts, and the interval of the same part was 30min- 1 hour, each group was 20ml, and the aerobic and anaerobic were 10ml respectively.

2. Patients with acute infective endocarditis, three groups of blood were collected within 30 minutes before treatment.

3. Patients with subacute infective endocarditis should take 2-3 groups of blood on the first day before treatment, with an interval of 30-60 minutes. If the result is negative, blood samples will be collected for culture on the second and third days, and no more than 4 groups will be collected within 24 hours.

4. Patients with catheter-related bloodstream infection, two groups of blood were collected for culture, the suspected infected catheter was collected 1 group, and the peripheral blood was collected 1 group, and both groups of blood were collected at the same time. Peripheral blood can be taken first, and catheter blood can be collected within 5 minutes. After the catheter was taken out, it was sent to the tip of the catheter for culture and blood culture samples were collected.