On February 5, the General Office of the National Health Commission and the Office of the State Administration of Traditional Chinese Medicine released the "Pneumonia Treatment Protocol for Novel Coronavirus Infection (Trial Version 5)". Compared with the previous edition, the "pharyngeal swab" in the clinical features of "laboratory tests" was updated to "nasopharyngeal swab".
1 Why is a nasopharyngeal swab more effective than an oropharyngeal swab?
Since the outbreak in Wuhan, there has been an influx of people coming to the hospital, and many health care providers have been busy, especially the fever clinic nurses, who not only take the temperature but also do pharyngeal swabs constantly in the face of suspected cases.
Pharyngeal swabs are used to take secretions from the pharynx and tonsils for bacterial culture or virus isolation, which can easily, quickly and accurately detect the type of virus and facilitate subsequent treatment, and is one of the effective methods to determine the new coronavirus.
Pharyngeal swabs are divided into two types: nasopharyngeal swabs and oropharyngeal swabs. Currently, most hospitals use oropharyngeal swabs to take specimens.
Based on the current data, the detection rate of novel coronavirus nucleic acid in nasopharyngeal swabs is higher than that of oropharyngeal swabs. This is why the new version of the "laboratory tests" in the treatment protocol uses nasopharyngeal swabs and other specimens with detectable nucleic acids of novel coronaviruses.
If a nasopharyngeal swab is not available, a nasal and pharyngeal swab should be collected and combined for influenza testing. If nasal and pharyngeal swab specimens cannot be collected, a nasal swab specimen from the middle turbinate is preferred over a pharyngeal swab specimen.
2 How to collect pharyngeal swabs properly?
To collect a nasopharyngeal swab.
Swab the bilateral pharyngeal tonsils and posterior pharyngeal wall with a polypropylene fiber-tipped plastic rod swab, swab the other polypropylene fiber-tipped plastic rod in the nasal tract at the nasal palate, stay for a few moments and then slowly turn to withdraw, then collect the other nostril in the same way, dip the removed rod into a test tube containing 3 ml of the sample solution and discard the tail, screw the cap on tightly, and indicate the name of the person from whom the sample originated and the date of collection on the outside of the tube.
Collection of oropharyngeal swabs.
A sterile swab is taken of the tonsils and posterior pharyngeal wall bilaterally, avoiding touching the tongue, and the swab head is dipped into the collection solution and the tail discarded.
One of the difficult populations during the collection of pharyngeal swabs is children, because the discomfort during the collection of pharyngeal swabs may lead to anxiety and fear in children and crying, making the collection more difficult.
The nurse should learn to distract the child and get the parents to cooperate, such as using colorful toys and watching small videos to reduce the child's psychological stress, and then collect the nasopharyngeal swab quickly. When the child cries due to discomfort, the left hand quickly presses the tongue with a tongue depressor and the right hand holds a sterile swab to collect the specimen.
3 How to store and send the pharyngeal swab?
After the throat swab is done, preservation and sending it for examination is also a very critical part, otherwise the result made may be inaccurate and cause errors in judging the condition.
Preservation of pharyngeal swabs.
Specimens are stored in a special refrigerator after collection. Specimens that can be tested within 48h are stored at 4℃; specimens that cannot be tested within 48h are stored below -70℃.
Pharyngeal swabs sent for examination.
All collected specimens must be sent to the Center for Disease Control within 48h in a refrigerated package by a dedicated vehicle for further testing in accordance with regulations. The temperature inside the specimen box is maintained at about 4℃ during transportation to ensure that the specimens are qualified and do not deteriorate.
4 Precautions for collecting pharyngeal swabs
(1) The collection and preservation of specimens and transportation must pay attention to aseptic operation, prevent contamination, and do standard preventive work to ensure that the collected specimens are qualified and the effectiveness of preservation and safety of transportation.
(2) Specimen collection personnel must undergo strict training and be qualified by examination before taking up the job, and the operation should follow a unified standard process for specimen collection and management to ensure the safety of patients and medical personnel themselves and people around them.
(3) For suspected cases, fasting water and no nebulized inhalation treatment before specimen collection to ensure smooth specimen collection and accuracy of test results. Collected nasal and pharyngeal swabs and collected in the same collection sample tube, in order to improve the separation rate and reduce workload.
(4) The collection principle is to collect every suspicious, not to spare a suspicious object, once found suspicious or confirmed cases of New Coronavirus pneumonia should be immediately isolated, and medical observation of medical personnel or other personnel who have come into contact with it, focusing on pregnant women, infants, the elderly and infirm and those with underlying diseases.
(5) One of the main ways of transmission of the new coronavirus is droplet transmission, so nursing staff must be quick and fast in the process of collecting pharyngeal swabs and take good self-protection measures, hats, N95 masks, eye protection, isolation gowns and gloves are essential. Hand washing must be done before and after collecting pharyngeal swabs to avoid cross infection.
5 What should I do if the patient has coughing and nausea during the collection process?
Those who have done oropharyngeal examination know that when the tongue depressor lightly presses the heel of the tongue, we may have a reflexive feeling of nausea, and some patients may even cough violently as a result.
Therefore, we need to be gentle, fast and accurate when sampling. And the collection of nasal swabs requires slow, light and steady movements so as not to irritate the patient's nasal mucosa and cause sneezing.
During the sampling process, we should pay attention to communication and exchange with the patient and his family and observe the patient's reaction. If the patient has a violent cough or nausea, wait for a few moments and collect after the patient feels comfortable. If the condition does not allow the collection, the collection should be suspended and collected again when the patient's condition permits.
