Nasopharyngeal swab collection, what do you need to be aware of?

With the development of new coronaviruses, many organizations are now using the collection of nasopharyngeal swabs to test for viral nucleic acids. This method is easy to use and is relatively popular. It is an effective way to quickly diagnose respiratory viral infection or carriage status.

Today, from an anatomical point of view, we will discuss the collection process needs to pay attention to the focus on improving the quality of testing, reducing the discomfort of the population, and avoiding the occurrence of adverse events.

First, let's understand the structure of certain regions of the hypopharynx. Some regions of the pharynx include the nasopharynx, oropharynx, and hypopharynx. The mucosa of the three regions is continuous and belongs to the upper respiratory tract.Rapid antigen nasal swab Nasopharyngeal swabs and oropharyngeal swabs just have different sampling paths. Oral sampling is an oropharyngeal swab and nasal sampling is a nasopharyngeal swab.

Let's now proceed to explore the secrets of the nasopharynx!

There are three prominent bony turbinates arranged in a trapezoidal pattern on the medial and lateral walls of the nasal cavity.

Under each turbinate is a fissure-like space called the upper, middle and lower nasal passages. The common narrow chamber between the turbinate and septum is called the common nasal passage. A superficially dilated postnasal venous plexus, called the naso-nasopharyngeal venous plexus, is located near the nasopharynx behind the lateral wall of the inferior nasal passages and is a favored site for postnasal bleeding.

Deviation of the nasal septum from the midline or irregular deviation can lead to nasal dysfunction, such as nasal congestion and nosebleeds.

What do healthcare professionals need to be aware of when taking a nasopharyngeal swab?

When collecting a nasal swab, the subject's head is tilted back and the swab is not directed along the nostrils, but rather in a perpendicular developmental direction to the face, entering through the common nasal passages. The swab is pressed down as much as possible, close to the lower wall of the patient's nasal cavity, into the electronic nasopharynx, there is a clear "wall feeling", soft can be rotated for a week to use the vertical data removal.

Do not use force if resistance is encountered or if the subject is in obvious pain during the collection process. Also, adjust the angle slightly in the sagittal plane before attempting entry.

Nasopharyngeal sampling, where the operator can stand behind the subject's side without looking directly into the mouth, is largely free of pharyngeal reflexes and is well tolerated, with a relatively low risk of exposure. After sampling, some subjects may have a sneezing reflex, which should be immediately covered with an elbow or tissue. A few subjects may have a small nosebleed after sampling, which usually stops on its own. If necessary, the bleeding site may be slightly constricted with an epinephrine-containing swab. When taking a nasopharyngeal swab, the swab may be left in the nasopharynx for a longer period of time to obtain a larger sample.

When taking a pharyngeal swab, the subject will open his or her mouth and make a long "ah" sound, using a tongue depressor if necessary. The pharyngeal swab gently and quickly wipes the lateral and posterior pharyngeal walls several times. Oropharyngeal swabs are commonly used in clinical practice because they can be performed with the mouth open and are relatively simple. However, when sampling via the oropharynx, the operator often needs to face the subject's mouth, with a higher risk of exposure.

Some studies have shown that the positivity rate of nasal swab samples is higher than that of pharyngeal swab samples, i.e. the sensitivity of viral nucleic acid detection is higher than that of pharyngeal swab samples. In clinical practice, nasal swab sampling should be preferred for viral nucleic acid testing. This will reduce missed diagnoses and the possibility of healthcare workers being exposed to the virus.

Nasal cavity, oropharynx as a respiratory, swallowing the main channel, exposed to the environment, in the research nucleic acid information collection, can not be avoided in order to avoid the company needs us to contact the mucous membrane of the upper respiratory tract, at the same time it will be through the stimulation of the nasal cavity or pharyngeal reflexes stress can be caused by the detected person sneezing, coughing, dry heaving and other situations, resulting in droplets or aerosols it can not be produced suspended in the air, significantly increasing the increase in the company's risk of cross-infection. If there is a latent period of the detected person in the case of unawareness of data collection, it has a source of infection, spread the development of pathways, very easy to influence lead to the main infection of the network virus.

Therefore, it is necessary to do a good job of protection in the detection, but also to improve the detection technology, get good cooperation to reduce the occurrence of adverse events.