As a noninvasive operation, nasopharyngeal specimen collection swab is the first choice for diagnosis, monitoring and differential diagnosis of Coronavirus epidemic. The sampling randomness is high, and the different location, strength and time of scraping specimens may cause false negative test results, which has adverse effects on the epidemic prevention and control work. During the operation, the patients coughed and splashed aerosol, and the medical staff were prone to occupational exposure. As the quality control leader of Hubei medical team, based on the standardized course of pharyngeal specimen collection swab issued by the laboratory medicine branch of Chinese Medical Association, the author adopted the unconventional supine position nasopharynx specimen collection swab method, and successfully collected dozens of cases. Now the experience is summarized as follows：

Effective communication and cooperation between nurses and patients contribute to the success of nasopharyngeal specimen collection swab

Before operation, the cooperation degree of patients should be evaluated effectively. Inform the patients of the purpose of collection and matters needing attention in advance. There are usually two groups of people who accept nasopharyngeal specimen collection swab. One is the suspected new crown patients to be diagnosed. Most of them have anxiety and fear, worry about the test results, and have uncertainty about the safety and comfort of sampling. It is urgent to exclude and make a diagnosis through nucleic acid detection, so as to determine the next treatment direction. The other group is the patients who are ready to be discharged from the hospital for nucleic acid retest. The new coronary symptoms of this group are significantly relieved, and their mentality has changed from the acceptance period to the positive coping period. Sampling operation indicates the prognosis and recovery of patients, and most patients can fully cooperate.

Individual protection is the foundation of successful specimen collection swab

Operator preparation: three level protection standard, it is recommended to wear positive pressure breathing head cover if possible, and check to ensure tight protection.

Sampling preparation: operation platform; Sampling materials, including sampling kit, inspection sheet and bar code, transport bag, hand disinfectant, ensure sterilization effect and validity.

Operation process: assist the patient to take the supine position, cushion the neck with soft pillow, and raise the chin by 15 °， Pull the mask down to cover the mouth and fully expose the patient's nasal cavity; After passing through the nostril, a polypropylene fiber head nasopharynx swab goes deep perpendicular to the coronal plane of the head, and reaches the posterior wall of the nasopharynx through the lower nasal meatus. When encountering resistance, gently lift the nasopharynx swab until it feels like touching the wall. The depth of the nasopharynx swab entering the nasal cavity is about the distance from the tip of the nose to the earlobe, and ask the patient to breathe normally; After the swab arrived at the nasal cavity, it stayed in the fornix for 15 seconds, then rotated the swab for 3 circles, slowly turned and then withdrew, and the swab was successfully retained; If necessary, in order to increase the viral load, the other nostril was collected by the same method. Immerse the two swabs in the same tube containing 3   ml sampling solution, discard the tail, tighten the tube cover, and place the tube vertically to ensure that the swab tip is immersed in the sampling solution.  

Tips for specimen collection swab

The nasopharynx swab should be inserted quickly without hesitation. Some patients do not tolerate the operation of nasopharynx swab probing into the nasal cavity, which may cause tears, foreign body sensation, etc. before the operation, ask the patients to inhale deeply in case of discomfort, so as to avoid coughing.

When the cotton specimen collection swab is inserted to the expected depth, do not continue to go deep, so as not to cause nasal mucosal injury and bleeding. During the stay, read the seconds with the patient's finger strokes. It can distract attention, eliminate tension, motivate patients and ensure successful collection.

Do not allow the patient to fully lift the head and bend the swab, which will lead to the incorrect position of the nasopharyngeal swab head, and ultimately affect the accuracy of specimen collection results.

The operator can select the left / right side of the operator according to his left and right handedness, and stand on the head and shoulder of the patient for operation. The head of the patient does not need to be biased to the opposite side, and it is difficult to control the entry angle of the swab when the head is on the side, which may cause mucosal irritation. For patients with excessive tension, the operator can hold the patient's hand tightly and give comfort.

In clinical practice, the author found that the collection of nasopharyngeal specimen collection swab in supine position has the following advantages:

(1) Reduce the irritation and injury of nasal mucosa. The collection posture of patients in supine position is more comfortable than that in sitting position, and it is easy to fix the head of patients, so that the nasopharyngeal specimen collection swab can smoothly enter into the posterior wall of nasopharynx, which can reduce the deviation of patients' position due to foreign body sensation conditioned reflex during operation, resulting in nasal mucosal injury and bleeding;

(2) It is easy to sample. The posture conforms to the physiological structure of human body, and conforms to human mechanics, which is convenient for the operator to collect samples;

(3) Reduce the risk of occupational exposure. Standing on the side of the patient, the operator can directly avoid the droplets and aerosols produced by the patient's cough and other splashing actions. The recumbent position starts from the details, and strives for one-step sampling operation to produce nucleic acid detection results quickly and accurately. It not only reduces occupation exposure of medical staff, but also reduces the false negative rate of new crown virus and saves epidemic prevention resources, which is worthy of clinical recommendation.