Background: Patients in the intensive care unit (ICU) often have serious infections, and anti-infection treatment is vital for these patients. Procalcitonin (PCT) is often used to identify bacterial infections and monitor the effectiveness of anti-infection treatments. This study aims to analyze the current research hotspots of the application of PCT in ICU patients, and to suggest future research directions. Methods:The Science Citation Index Expanded (SCI-EXPANDED) database in the Web of Science Core Collection (WOSCC) was used as the data source to search literature from 1995 to February 6, 2021. The search strategy was subject term = procalcitonin AND Web of Science categories = Critical Care Medicine.Using CiteSpace software, literature on the application of PCT in ICU patients was analyzed.Results: A total of 1,243 papers, including 665 (53.5%) original articles, 87 (7.0%) reviews, 93 (7.5%) letters, 297 (23.9%) conference abstracts, and 101 (8.1%) other articles, were analyzed. The citation frequency was 40,442, the h-index was 96, and the average number of citations per item was 32.54. Research was mainly from the United States, Germany, France, and Spain, amongst others. The research institutions

Background: Procalcitonin (PCT) can effectively identify bacterial infections and can be used for risk prediction and antimicrobial treatment in patients with unexplained fever and critically ill patients. In this study, statistical analyses of the literature were performed to clarify the application and research status of PCT in respiratory diseases. Future research directions are discussed.Methods: A literature search was conducted using the Science Citation Index Expanded (SCI-EXPANDED) database in the Web of Science Core Collection (WOSCC). Published literature between 1995 and February 6, 2021 were searched using the following strategies: subject term = procalcitonin; and Web of Science categories = Respiratory System. Using the Citespace software, the literature on the application of PCT in patients with respiratory diseases was analyzed in terms of annual publication status, subject distribution, country/institution distribution, journal distribution, author distribution, and keywords.Results: A total of 542 related research literatures were identified, with the number of published papers and the number of literature citations increasing yearly. Research was mainly concentrated in the United States, China, Switzerland, and other countries, with countries such as the United Kingdom, the United States, and Canada being involved in international collaborations. Research institutions were mainly universities or hospitals such as the