If pharyngeal swab nucleic acid test specimen collection is not done properly, it may result in a "false negative" result and delay treatment for the patient. So, what is the key to pharyngeal swab nucleic acid test specimen collection?
Dr. Tian Peng, deputy chief physician, said that whether it is a nasopharyngeal swab or an oropharyngeal swab, the depth of collection and the length of contact with the mucosa are key.
If the nasopharyngeal swab is not collected deep into the nasopharyngeal cavity, or if the patient vomits during the collection of the oropharyngeal swab, resulting in insufficient sampling time, the majority of cells collected may be cells that do not contain the virus, which may result in a "false negative". This may also be one of the reasons why patients with multiple negative nucleic acid tests have been reported to have a positive nucleic acid test when retested.
Physicians and nurses who do not specialize in otolaryngology and do not know the structure of the nasal cavity and nasopharynx are often unsure about the procedure of collecting nasopharyngeal swabs. For this reason, three deputy chief physicians, Liang Faya, Tian Peng and Cai Yuexin, respectively, conducted training in their wards and made a video of the nasopharyngeal swab sampling process for this purpose, which was placed inside the WeChat group so that everyone could watch it repeatedly and master the key points.
"After 2 demonstrations in the 11th floor east joint ward, where deputy chief physician Tian Peng and I are located, teammates from other hospitals quickly mastered the method, indicating that the method is not difficult." Liang Faya, deputy chief physician, said that a small number of patients may have a small amount of nasal bleeding after sampling, which can generally stop on its own, and if necessary, a swab with epinephrine can be used to slightly constrict the bleeding site to stop bleeding.
Different parts of the human body: nasal swabs are mainly collected from the nasal cavity (whether the collection of nasal swabs or pharyngeal swabs, the depth of collection is the key, the collection of nasal swabs not taken to the depth of the nasal cavity, it is possible that the cells collected do not contain the virus, i.e., may cause false negatives) The following gives you an introduction to the structure of our Medico nasal swabs what are the differences?
First of all, we would like to introduce you to our kit.
Kit includes: ①, a disposable sampling swab; ② a sampling tube (2ml preservation solution); ③ a saline; ④ contains instructions.
2、Preparation and precautions before sampling.
* Do not use nasal drops or nasal wash to rinse the nasal cavity the day before sampling.
*If there is runny nose, nosebleed or nasal discomfort on the day of sampling, it is recommended to consult a doctor.
3、Sampling steps.
①Remove the sampling tube containing the preserved liquid and place it in an easy-to-reach place for backup.
②Remove the sampling swab and dip it into sterile saline to moisten the swab tip.
Note: Do not touch the area below the fracture point.
③ . Extend the sampling swab into the left nasal cavity and reach as far inward as possible along the nasal septum (the swab tip all the way into the interior of the nasal cavity) so that the swab tip touches the nasal mucosa and gently turns in a circle for 3 weeks.
(Note: not rubbing at the entrance of the nasal cavity, avoid touching the skin at the entrance of the nasal cavity when inserting and removing the sampling swab.)
④ . Extend the same sampling swab into the right nasal cavity and perform the same operation as in the previous step.
⑤. Holding the swab in your hand, carefully unscrew the sample collection tube of the preserved fluid.
Note: Do not tip the collection tube; do not touch the swab head.
⑥. Quickly place the sample-soaked swab into the collection tube and break it by pressing a break against the wall of the 2 ml collection tube mouth, leaving the swab head inside the collection tube liquid.
⑦. Tighten the collection tube and shake it gently from side to side for 3 times. Send it to the testing site for testing and you're done.
The above is the method of self-sampling, if you do not dare to pick your own partners, you can go to the hospital sampling, or ask a partner to help sampling, the following is the method of asking others to sample, (please sampler must see)
①. Ask the patient to keep his head still and remove the secretions from the surface of the nostrils. The collector can stand to the side of the sampled person to reduce the spread of virus due to coughing and sneezing (please try to wear protective clothing for sampling, protecting yourself is first)
②Measure the distance from the nostril to the ear root with a swab and mark it with your hand.
③Gently (put away your grumpy temper, be gentle) insert the swab through the nasal cavity in a vertical nose (face) direction into the nostril, with the feeling of touching the wall (no more poking in), so that the swab stays in the nose for 15-30 seconds, and then gently rotate it 3 times.
④Put the swab into the viral medium and break the swab stick so that it is completely placed in the tube.
⑤ Screw the cap of the tube, mark it well and put it into a plastic bag and seal it well.
⑥Send the specimen for examination in time.
