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Figure.  Anatomical Structures Related to Nasopharyngeal Sampling
Anatomical Structures Related to Nasopharyngeal Sampling

Correct placement of the swab and origins of the nasal bleeds in this study. The life-threatening bleeds resulted from the anterior ethmoid artery, 1 from the lateral and 1 from the medial nasal wall (blue asterisks). One bleed resulted from the sphenopalatine artery (black asterisk), and in 1 case, the bleeding site could not be identified. A, Anterior view; B, Lateral wall of nasal cavity; C, Medial wall of nasal cavity.

Table.  Treatment and Sequelae of 8 Patients Treated for Complications After SARS-CoV-2 Nasopharyngeal Swab Test
Treatment and Sequelae of 8 Patients Treated for Complications After SARS-CoV-2 Nasopharyngeal Swab Test
1.
Mughal  Z, Luff  E, Okonkwo  O, Hall  CEJ.  Test, test, test—a complication of testing for coronavirus disease 2019 with nasal swabs.   J Laryngol Otol. 2020;134(7):646-649. doi:10.1017/S0022215120001425PubMedGoogle ScholarCrossref
2.
De Luca  L, Maltoni  S.  Is naso-pharyngeal swab always safe for SARS-CoV-2 testing? an unusual, accidental foreign body swallowing.   Clin J Gastroenterol. 2021;14(1):44-47. doi:10.1007/s12328-020-01236-yPubMedGoogle ScholarCrossref
3.
Hussain  MH, Siddiqui  S, Mahmood  S, Valsamakis  T.  Tracheal swab from front of neck airway for SARS-CoV-2; a bronchial foreign body.   BMJ Case Rep. 2020;13(8):e237787. doi:10.1136/bcr-2020-237787PubMedGoogle Scholar
4.
Sullivan  CB, Schwalje  AT, Jensen  M,  et al.  Cerebrospinal fluid leak after nasal swab testing for coronavirus disease 2019.   JAMA Otolaryngol Head Neck Surg. 2020;146(12):1179-1181. doi:10.1001/jamaoto.2020.3579 PubMedGoogle ScholarCrossref
5.
Green  DA, Zucker  J, Westblade  LF,  et al.  Clinical performance of SARS-CoV-2 molecular tests.   J Clin Microbiol. 2020;58(8):e00995-20. doi:10.1128/JCM.00995-20PubMedGoogle Scholar
6.
Higgins  TS, Wu  AW, Ting  JY.  SARS-CoV-2 nasopharyngeal swab testing—false-negative results from a pervasive anatomical misconception.   JAMA Otolaryngol Head Neck Surg. 2020;146(11):993-994. doi:10.1001/jamaoto.2020.2946PubMedGoogle ScholarCrossref
Research Letter
April 29, 2021

Complications of COVID-19 Nasopharyngeal Swab Test

Author Affiliations
  • 1Department of Otorhinolaryngology–Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
  • 2HUS Diagnostic Center, HUSLAB, Clinical Microbiology, Helsinki University Hospital, Helsinki, Finland
JAMA Otolaryngol Head Neck Surg. 2021;147(7):672-674. doi:10.1001/jamaoto.2021.0715

During the COVID-19 pandemic, numerous swab samples have been taken for SARS-CoV-2 reverse transcriptase–polymerase chain reaction (RT-PCR) testing. Nasopharyngeal sampling is considered safe, despite adjacent vital structures (eg, orbit, skull base, rich vasculature; Figure). However, single case reports1-4 and clinical observations indicate the possibility of severe complications. This case series investigated the frequency and type of SARS-CoV-2 nasopharyngeal test complications.

Methods

All patients presenting to the dedicated otorhinolaryngology emergency department (ED) of Helsinki University Hospital Department of Otorhinolaryngology–Head and Neck Surgery between March 1 and September 30, 2020, were retrospectively screened for complications after SARS-CoV-2 nasopharyngeal swab sampling. Those experiencing sampling complications underwent medical record review.

The number of SARS-CoV-2 tests performed in the catchment population (1.6 million people) of the Helsinki University Hospital during the same time period was obtained from the Finnish Institute for Health and Welfare. This study was approved by the Research Administration of Helsinki University Hospital (HUS/58/2020). As this was a retrospective registry study with no patient intervention, ethics committee approval and informed consent were not required by Finnish national legislation in accordance with the Medical Research Act of Finland 488/1999.

Results

During the 7-month study period, 643 284 SARS-CoV-2 RT-PCR tests were performed. Eight complication-related visits (7 females, 1 male; age range, 14.0-78.6 years; mean [SD] age, 39.5 [20.9] years) were identified in 2899 otorhinolaryngology ED patients—4 nasal bleeds and 4 broken swabs, all occurring immediately after sampling (Table). None of these 8 patients tested positive for COVID-19.

The frequency of complications requiring treatment in the ED was 1.24 per 100 000 performed SARS-CoV-2 tests. The broken swabs were removed via nasal endoscopy under local anesthesia, whereas the nasal bleeds required medication, numerous nasal packings, and surgical and endovascular procedures and led to fetal risk, sepsis, and blood transfusions (Table). Half of the bleeds were potentially life threatening (hemoglobin level fell below 6.5 g/dL [to convert to g/L, multiply by 10.0]). Massive bleeding complicated localization of the bleeds (shown in Figure). Infections, as well as intranasal adhesions and septal perforations, likely resulted from the repetitive nasal packings.

Discussion

Timely and reliable testing is important in controlling the COVID-19 pandemic. Nasopharyngeal swab RT-PCR testing is often used as the main diagnostic test method because it yields early results with moderate sensitivity and excellent specificity.5

The frequency of complications was extremely low in this study. All complications seemed to involve an incorrect sampling technique: excess use of force or an overly cranial direction of the swab. While the patients who experienced broken swabs fared well, the patients with epistaxis had rockier recuperations. The complications also exposed personnel to the risk of an aerosol-generating procedure.

Literature regarding SARS-CoV-2 sampling complications is scarce. Breaking of the swab tip has resulted in a foreign body in the nasal cavity,1 the esophagus2 and, after sampling through tracheostomy, the bronchus.3 A case of test-related cerebrospinal fluid leak, probably owing to preexisting encephalocele, has been reported.4

Sampling should always be performed bearing in mind the anatomical structures of the nasal cavity and its surroundings to ensure safe sampling and correct results.5,6 Force should never be used, especially in patients with known prior operations of the nose or skull base. The sampling swab should be directed along the nasal floor, not too laterally nor too cranially, until resistance is encountered (Figure).6

The retrospective setting is a limitation of this study. It should be noted that Finland has a national public health service. Of the Helsinki University Hospital’s catchment population (1.6 million), all severe acute otorhinolaryngology problems are treated solely in our 1 ED. Patients presenting with minor complications may have been treated at other facilities, but we did not have access to this information. Furthermore, no private otorhinolaryngologist offices have been open for patients with suspected COVID-19. Nevertheless, this study is an apt representation of patients with SARS-CoV-2 nasopharyngeal swab test complications in a large tertiary care referral center.

Based on the results, the risk for a severe complication requiring specialist-level care after SARS-CoV-2 nasopharyngeal swab testing is extremely low. Nonetheless, complications involve anatomically challenging locations and may be life threatening. To avoid complications, correct sampling techniques are crucial.

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Article Information

Accepted for Publication: March 15, 2021.

Published Online: April 29, 2021. doi:10.1001/jamaoto.2021.0715

Corresponding Author: Anni Koskinen, MD, PhD, Department of Otorhinolaryngology–Head and Neck Surgery, Helsinki University Hospital, PO Box 263, FI-00029, Helsinki, Finland (anni.koskinen@hus.fi).

Author Contributions: Dr Lamminmäki had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: All authors.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: All authors.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: All authors.

Administrative, technical, or material support: All authors.

Supervision: Lamminmäki.

Conflict of Interest Disclosures: None reported.

Additional Contributions: The authors wish to thank Martta Lamminmäki for the medical illustrations. She did not receive compensation.

References
1.
Mughal  Z, Luff  E, Okonkwo  O, Hall  CEJ.  Test, test, test—a complication of testing for coronavirus disease 2019 with nasal swabs.   J Laryngol Otol. 2020;134(7):646-649. doi:10.1017/S0022215120001425PubMedGoogle ScholarCrossref
2.
De Luca  L, Maltoni  S.  Is naso-pharyngeal swab always safe for SARS-CoV-2 testing? an unusual, accidental foreign body swallowing.   Clin J Gastroenterol. 2021;14(1):44-47. doi:10.1007/s12328-020-01236-yPubMedGoogle ScholarCrossref
3.
Hussain  MH, Siddiqui  S, Mahmood  S, Valsamakis  T.  Tracheal swab from front of neck airway for SARS-CoV-2; a bronchial foreign body.   BMJ Case Rep. 2020;13(8):e237787. doi:10.1136/bcr-2020-237787PubMedGoogle Scholar
4.
Sullivan  CB, Schwalje  AT, Jensen  M,  et al.  Cerebrospinal fluid leak after nasal swab testing for coronavirus disease 2019.   JAMA Otolaryngol Head Neck Surg. 2020;146(12):1179-1181. doi:10.1001/jamaoto.2020.3579 PubMedGoogle ScholarCrossref
5.
Green  DA, Zucker  J, Westblade  LF,  et al.  Clinical performance of SARS-CoV-2 molecular tests.   J Clin Microbiol. 2020;58(8):e00995-20. doi:10.1128/JCM.00995-20PubMedGoogle Scholar
6.
Higgins  TS, Wu  AW, Ting  JY.  SARS-CoV-2 nasopharyngeal swab testing—false-negative results from a pervasive anatomical misconception.   JAMA Otolaryngol Head Neck Surg. 2020;146(11):993-994. doi:10.1001/jamaoto.2020.2946PubMedGoogle ScholarCrossref
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