2.2 Methodology
We conducted a retrospective, single-center study using medical charts from the hospital database of our institute. The clinical and demographic profiles of the patients, including age, sex, and body mass index; presence of diabetes mellitus (DM), hypertension, primary diseases, or airway emergency; method of anesthesia (local anesthesia without intubation or general anesthesia); use of antithrombotic drugs; presence of complications; blood test values, were analyzed.
Complications were reviewed with respect to the incidences of bleeding, infection, and subcutaneous emphysema. We defined “bleeding” as bleeding lasting 1 week after ST or bleeding that required surgical hemostasis; “infection” as a condition requiring the application of antibiotic ointments or surgical treatment, including the excision of the infected area; “subcutaneous emphysema” as the evident presence of subcutaneous emphysema around the tracheostoma.
Blood test values were reviewed to determine the albumin level, lymphocyte count, platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), and prothrombin time-international normalized ratio (PT-INR). The abnormal ranges for albumin level, lymphocyte count, platelet count, PT, APTT, and PT-INR were defined as <3.0 g/dL, <1500/μL, <50000/μL, >14 s, >40 s, and >1.5, respectively.
We also extracted the data of patients who underwent ST under CAT. Thereafter, we compared the patient backgrounds and risks of complications after ST between the antithrombotic naïve patients and patients undergoing CAT. Furthermore, we analyzed the risk factors for complications after ST.