A comparison of the features of RT-PCR positive and negative COVID-19 pneumonia patients in the intensive care unit



COVID-19 pneumonia, Intensive care unit, mortality, RT-PCR


Background/Aim: COVID-19 is a serious disease, primarily affecting the respiratory system. The disease spreads from person to person and has become a global health problem of great concern worldwide. The aim of this study was to compare the clinical and laboratory characteristics and the mortality rates of suspected and confirmed COVID-19 cases admitted to the intensive care unit with severe pneumonia. Methods: A retrospective case-control study examination was made of 397 patients diagnosed with suspected or confirmed COVID-19 who were followed up in the intensive care unit (ICU) of Afyonkarahisar Health Sciences University Medical Faculty Hospital between 20 March 2020 and 31 December 2020. The cases were compared in respect of demographic, clinical and laboratory characteristics, prognosis, and mortality rates. Results: 397 patients comprised of 37 (9.3%) with suspected COVID-19 and 360 (90.7%) confirmed COVID-19. No difference was determined between the suspected and confirmed cases in respect of age, gender, and comorbidities (P<0.05). Malignancy was determined in 14 (37.8%) and in 33 (9.2%) of the suspected and confirmed COVID-19 cases, respectively. PaO2 and PaO2/FiO2 values of the confirmed COVID-19 patients were found to be significantly lower than those of suspected COVID-19 cases (P=0.027 and P=0.018, respectively). No statistically significant difference was determined between the mortality rates of suspected and confirmed COVID-19 patients (59.5% and 56.1%, respectively, P=0.731). Conclusion: When the blood analyses of 397 patients who were hospitalized in ICU with an initial diagnosis of severe COVID-19 pneumonia, regardless of COVID-19 RT-PCR test results, were compared, the LDH and CK values were determined to be significantly high, whereas PaO2 and PaO2/FiO2 values were significantly low. Since the sensitivity of RT-PCR test is low especially in cancer patients, it leads to false negative tests in a significant proportion of patients in acute phase of the disease. Therefore, the majority of patients with COVID-19 are not detected by this test, and clinical symptoms, as well as CT scans, are important to identify patients with COVID-19. Since COVID-19 infection has similar initial symptoms to other pneumonias, it is recommended to study other respiratory viral agents in patients with a negative RT-PCR test.


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Orhan S, Demirtürk N, Taşdemir Mecit BB, Bozkurt E, Dizen Kazan E, Yavuz T, Köseoğlu Toksoy C, Dural İbrahim E, Sarı A, Çoşğun İbrahim G, Gülsoy KY, Kazan S. A comparison of the features of RT-PCR positive and negative COVID-19 pneumonia patients in the intensive care unit. J Surg Med [Internet]. 2022 Apr. 1 [cited 2022 Aug. 18];6(4):440-4. Available from: https://jsurgmed.com/article/view/961334