Background and Objectives: Tracheostomy is a relatively safe procedure, and the recent emergence of COVID-19 has raised the need to perform tracheostomy immediately in the bed of an intensive care unit (ICU) rather than an operating room. The purpose of this study was to determine the occurrence of complications related to surgical tracheotomy performed in the ICU by an ENT specialist.Materials and Method From March 2019 to January 2022, a total of 101 patients underwent tracheostomy in the ICU. Demographics and complications were classified according to postoperative period. Results: Within 24 hours after the procedure, bleeding events were confirmed in 2 patients (2.0%) with mild bleeding. One case (1.0%) of ventricular fibrillation occurred shortly after the procedure. There were no complications from 24 hours to 1 week after procedure. After one week, 4 patients (4.5%) had a local infection, and 3 patients (3.4%) had a tube obstruction. During all follow-up periods, there were no serious side effects such as death, major vascular injury, pneumothroax. No complications were observed throughout the entire period in 6 COVID-19 patients. Conclusion The number of complications of surgical tracheotomy in the ICU performed by a specialist was lower than in previous studies, and there were no complications that delayed treatment or endangered life. The ENT training hospitals should provide sufficient training opportunities for residents to perform surgical tracheostomy and strive to minimize complications associated with the procedure and pre- and post-operative management under the detailed guidance and supervision of specialists.

Purpose: To determine seasonal variations in serum potassium levels among hemodialysis patients. Materials and Methods: This was a multicenter cohort study of patients whounderwent hemodialysis and were registered in DialysisNet at our four associated general hospitals between January and December 2016. Month-to-month potassium variability was quantified as SD/√{n/(n-1)}, and a non-hierarchical method was used to cluster groups according to potassium trajectories. Seasonal variations in potassium levels were analyzed using a cosinor analysis. Results: The analysis was performed on 279 patients with a mean potassium level of 5.08±0.58 mmol/L. After clustering, 52.3% (n=146) of patients were included in the moderate group (K+ , 4.6±0.4 mmol/L) and 47.7% (n=133) in the high group (K+ , 5.6±0.4 mmol/L). The mean potassium level peaked in January in the moderate group (4.83±0.74 mmol/L) and in August in the high group (5.51±0.70 mmol/L). In the high potassium group, potassium levels were significantly higher in summer than in autumn (p<0.001) and spring (p=0.007). Month-to-month potassium variability was greater in the high group than in the moderate group (0.59±0.19 mmol/L vs. 0.52±0.21 mmol/L, respectively, p=0.012). Compared to patients in the first quartile of potassium variability (≤0.395 mmol/L), those with higher variability (2nd–4th quartiles) were 2.8–4.2 fold more likely to be in the high potassium group. Conclusion Different seasonal patterns of serum potassium were identified in the moderate and high potassium groups, with potassium levels being significantly higher in the summer season in the high potassium group and in winter for the moderate potassium group.