Tracheostomy is a procedure that establishes an airway for patients who cannot breathe normally for various reasons. This intervention involves making an incision in the trachea and inserting a tube. While tracheostomy has several indications, it is commonly used to provide an open airway for critically ill patients who require long-term ventilator support [1]. Two forms of tracheostomy are employed: open surgical tracheostomy (OST) and percutaneous tracheostomy (PCT). PCT is recognized as a safe and cost-effective alternative to OST [2,3] and can be performed using different techniques, with bronchoscopy and ultrasound being the most prevalent. PCT has several reported advantages over OST. It can be carried out immediately at the bedside, which minimizes the risks associated with patient transport; furthermore, it requires fewer personnel and no operating room, thus reducing costs [4]. Bronchoscopic PCT is currently the preferred method due to its value in accurately identifying the central part of the trachea, monitoring for bleeding at the incision site, and clearing sputum or blood from the airway during the procedure [4]. However, ultrasound-guided PCT (UPCT) exclusively utilizes ultrasound, which can be easier to use than a bronchoscope. UPCT also enables the visualization of vascular structures and the thyroid gland in the neck, reducing the risk of complications from vascular perforation or thyroid injury [5,6]. Using ultrasound to confirm anatomical landmarks can help prevent bleeding from the pre-tracheal vasculature and ensure accurate placement of the tracheal tube above the first tracheal ring [6,7]. However, to our knowledge, few studies have reported outcomes of UPCT in South Korea. Thus, this study aimed to evaluate the incidence of complications in critically ill patients who underwent UPCT, with a focus on bleeding risk.

Study population and ethical approval

We retrospectively examined data from patients admitted to the intensive care unit (ICU) of Gyeongsang National University Hospital who underwent UPCT between March 2018 and April 2023. The study included a total of 81 patients aged 15 years or older. Using medical records and electronic laboratory results, we analyzed information on patient demographics, reasons for ICU admission, patient status prior to tracheostomy, the use of anticoagulants or antiplatelet agents, and complication rates with or without extracorporeal membrane oxygenation (ECMO). Subsequently, we investigated risk factors for bleeding necessitating blood transfusion, a serious potential complication.

Ultrasound-guided percutaneous tracheostomy method

We utilized the Ciaglia Blue Rhino Percutaneous Dilatational Tracheostomy Kit (Cook Critical Care, Bloomington, IN, USA) for PCT. The PCT kit included a knife, a needle, a syringe, a guide wire, and both small and curved dilators. For all patients, a tracheal tube ranging in size from 7.0 to 8.0 mm was employed. The tracheostomy site was initially determined based on standard anatomical landmarks. Subsequently, ultrasound imaging was employed to locate the cricoid cartilage, tracheal rings, and thyroid gland. This was followed by the identification of nearby arteries, veins, and the endotracheal tube (Fig. 1). Ultimately, the puncture site was determined. An assistant, positioned next to the patient’s head, was instructed to retract the endotracheal tube by approximately 5 to 8 cm and then resecure it. A skin incision, measuring roughly 1 to 2 cm, was made at the puncture site. Puncture was performed with a syringe filled with water, and the formation of air bubbles within the syringe confirmed successful entry into the trachea. A guide wire was then inserted through the puncture. The puncture site was initially expanded with a small dilator, followed by further dilation using a curved dilator to adequately expand the skin and tracheal opening. The tracheal tube was then inserted. Once the ventilator’s normal operation was confirmed with the tracheostomy tube in place, the endotracheal tube was removed.

Figure 1. Ultrasound transverse view. The red arrow indicates the vessel, the green arrow denotes the thyroid, and the blue arrow indicates the tracheal ring.

Definitions and data analysis

The study classified complications into minor and major categories for analysis. Minor complications included transient hypotension, transient hypoxia, minor bleeding not necessitating blood transfusion, granuloma formation, atelectasis, and tracheal cuff puncture. Minor bleeding was defined as any bleeding that necessitated the replacement of the gauze at the tracheostomy site within 2 hours. In contrast, major complications encompassed bleeding that required blood transfusion within 8 hours, surgical site infection necessitating additional antibiotic therapy, conversion to open surgery due to procedural failure, and subsequent airway surgery due to bronchial stenosis. The frequency of each complication was examined.

Missing data were not replaced or imputed. Data are presented as means and standard deviations or as numbers (percentages). To evaluate the risk factors associated with hospital mortality, logistic regression analysis was employed. p-values of less than 0.05 were considered to indicate statistical significance. Statistical analyses were performed using IBM SPSS ver. 24.0 (IBM Corp., Armonk, NY, USA).

Ethics statement

Due to the retrospective nature of this study, the requirement for informed consent was waived. The study protocol was approved by the institutional review board of Gyeongsang National University Hospital (GNUH-2024-04-017).

In this analysis, 81 patients underwent UPCT, including 54 men (67%) and 27 women (33%). The mean patient age was 64.91±15.32 years, the mean body mass index was 24.33±5 kg/m², and the mean Simplified Acute Physiology Score 3 was 48.17±19.76. Comorbidities were present in 61 patients (75.3%). Of these, 28 patients (34.6% of the total) had diabetes mellitus, 34 (42%) had hypertension, 11 (13.6%) had chronic obstructive pulmonary disease, 16 (19.8%) had chronic kidney disease, and 13 (16%) had acute respiratory distress syndrome. Following surgery, 62 patients (76.5%) were admitted to the ICU. Regarding types of surgery, 31 patients (38.3%) underwent valve surgery, 17 (21%) had coronary surgery, 13 (16%) had aortic surgery, and 7 (8.6%) underwent other types of surgical procedures. The sample included 14 patients (17.1%) who were admitted to the ICU due to trauma, and 21 patients (25.9%) who received ECMO for various indications (Table 1).

Table 1 . Demographical characteristics of patients (n=81).

Characteristic	Value
Age (yr)	64.91±15.32
Male sex	54 (66.7)
Body mass index (kg/m2)	24.33±5.00
Simplified Acute Physiology Score 3	48.17±19.76
Diabetes mellitus	28 (34.6)
Hypertension	34 (42.0)
Chronic obstructive pulmonary disease	11 (13.6)
Chronic kidney disease	16 (19.8)
Acute respiratory distress syndrome	13 (16.0)
Surgery before ICU admission	62 (76.5)
Valve	31 (38.3)
Coronary	17 (21.0)
Aorta	13 (16.0)
Other	7 (8.6)
Trauma before ICU admission	14 (17.1)
Extracorporeal membrane oxygenation	21 (25.9)

Values are presented as mean±standard deviation or number of patients (%)..

ICU, intensive care unit..

Regarding patient characteristics prior to UPCT, the average duration of mechanical ventilation before UPCT was 8.75±7.01 days. The mean hemoglobin level was 10.82±1.77 g/dL, the platelet count was 143.7±84.57×10³/mm³, and the international normalized ratio was 1.22±0.7. The sample had a mean systolic blood pressure of 121.27±22.76 mm Hg, a heart rate of 86.54±19.52 beats per minute, and an saturation pulse oxygen level of 97.04%±5.88%. Of the patients, 43 (53.1%) were on anticoagulant therapy, and 20 (24.7%) were taking antiplatelet medications (Table 2).

Table 2 . Patient characteristics at the time of ultrasound-guided percutaneous tracheostomy (n=81).

Characteristic	Value
Days of ventilation before UPCT	8.75±7.01
Hemoglobin level (g/dL)	10.82±1.77
Platelet count (103/mm3)	143.7±84.57
International normalized ratio	1.22±0.70
Systolic blood pressure (mm Hg)	121.27±22.76
Heart rate (bpm)	86.54±19.52
Oxygen saturation (%)	97.04±5.88
No. of patients on anticoagulants (%)	43 (53.1)
No. of patients on antiplatelet drugs (%)	20 (24.7)

Values are presented as mean±standard deviation or number of patients (%)..

UPCT, ultrasound-guided percutaneous tracheostomy..

Table 3 presents the complications associated with UPCT. Minor complications arose in 20 patients (24.7%). The most frequent minor complication was bleeding not necessitating blood transfusion, occurring in 15 patients (18.5%). Atelectasis was noted in 3 patients (3.7%), hypotension in 2 patients (2.5%), hypoxemia in 1 patient (1.2%), and tracheal cuff puncture in 1 patient (1.2%). Major complications occurred in 7 patients (8.6%), all of whom experienced bleeding that required blood transfusion. No cases included complications such as infection, conversion to open surgery, or surgery to treat tracheal stenosis. Table 4 presents the results of logistic regression analysis, which revealed no statistically significant risk factors for major bleeding.

Table 3 . Complications of ultrasound-guided percutaneous tracheostomy.

Complication	No. of patients (%)
Minor complications	20 (24.7)
Hypotension	2 (2.5)
Hypoxemia	1 (1.2)
Tracheal cuff puncture	1 (1.2)
Bleeding	15 (18.5)
Granuloma	0
Atelectasis	3 (3.7)
Major complications	7 (8.6)
Bleedinga)	7 (8.6)
Infection	0
Conversion to open surgery	0
Surgery for tracheal stenosis	0

^a)Major bleeding was defined as bleeding requiring blood transfusion..

Table 4 . Logistic regression analysis of risk factors for major bleeding.

Risk factors	OR (95% CI)	p-value
Age	0.986 (0.940–1.034)	0.563
Male sex	0.308 (0.035–2.695)	0.287
Body mass index	1.100 (0.943–1.284)	0.223
SAPS 3	1.001 (0.962–1.041)	0.971
Diabetes mellitus	0.290 (0.033–2.539)	0.264
Hypertension	0.207 (0.024–1.806)	0.154
COPD	1.067 (0.116–9.816)	0.955
Chronic kidney disease	0.656 (0.073–5.876)	0.706
ARDS	4.800 (0.932–24.710)	0.061
Surgery	1.705 (0.310–9.370)	0.540
Trauma	0.782 (0.087–7.058)	0.827
ECMO	4.471 (0.910–21.965)	0.065
Hemoglobin level	0.757 (0.366–1.567)	0.453
Platelet count	1.000 (1.000–1.000)	0.818
INR	1.840 (0.870–3.893)	0.111
Systolic blood pressure	0.987 (0.948–1.027)	0.522
Anticoagulants	2.368 (0.432–12.991)	0.321
Antiplatelet drugs	1.244 (0.222–6.975)	0.804

OR, odds ratio; CI, confidence interval; SAPS 3, Simplified Acute Physiology Score 3; COPD, chronic obstructive pulmonary disease; ARDS, acute respiratory distress syndrome; ECMO, extracorporeal membrane oxygenation, INR, international normalized ratio..

Various interventions are commonly performed to support critically ill patients, and tracheostomy is one such procedure. Tracheostomy serves to protect the vocal cords, efficiently remove sputum, and reduce dead space in patients who require long-term ventilation [1]. Traditionally, this procedure has been conducted surgically, but more recently, methods involving endoscopy or ultrasound have been employed [3,4]. While OST has been practiced for many years and is well-documented, the literature includes a relative paucity of research on UPCT. Thus, we sought to investigate the safety of UPCT by examining the frequency of complications associated with the procedure. We retrospectively reviewed the medical records of 81 patients who underwent UPCT at Gyeongsang National University Hospital between March 2018 and April 2023. The analysis focused on the associations between major complications—particularly bleeding that necessitated blood transfusion—and the baseline characteristics and status of patients prior to UPCT.

Tracheostomy can have several notable complications. Tracheal stenosis, or the narrowing of the airway, may result from prolonged reliance on a tracheostomy tube and is one of the most frequent complications associated with the procedure. This condition arises from granuloma formation, which occurs due to irritation from excessive cuff pressure and the accumulation of secretions. While nearly all patients who undergo tracheostomy develop some degree of tracheal stenosis, only a subset—ranging from 3% to 12%—experience clinically significant stenosis that necessitates intervention or surgery [8]. Notably, our study included no instances of tracheal stenosis, with no cases requiring surgery or other interventions.

Another key complication following tracheostomy is infection at the procedure or surgical site. Prophylactic antibiotics are generally not recommended for tracheostomy. In the present study, none of the patients received antibiotics for tracheostomy. Symptomatic wound treatment is usually sufficient for mild infections; however, surgical intervention, such as debridement of necrotic tissue, may be necessary for organ infections involving necrosis. In a previous report, the incidence of surgical site infection after tracheostomy was 6.6% [9]. However, in our study, none of the participants required wound care due to infection.

Major bleeding is a common and serious complication of tracheostomy. A previous study reported an incidence of major bleeding of approximately 5.7% [9]. In our study, the incidence of major bleeding was 8.6% (due to the patient’s overall condition, 6 patients were receiving blood transfusions before tracheostomy, and 1 patient did not receive blood transfusion), which was relatively high compared to past results; however, no patient deaths occurred. The reason for a relatively higher risk of major bleeding in this study was that major 8 bleeding was defined only as a case requiring blood transfusion, compared to other papers that defined major bleeding as a case where a blood vessel ruptures or surgery is required.

We compared the incidence of major bleeding during tracheostomy among patients on anticoagulants and antiplatelet agents with the findings of Markota et al. [10], who reported tracheostomy outcomes with and without dual antiplatelet therapy. The results of that study showed no significant differences in complications following tracheostomy, including the need for post-tracheostomy transfusion (p=0.59). However, another report indicated that patients regularly taking antiplatelet agents or anticoagulants before tracheostomy faced a higher bleeding risk compared to those who were not (26.8% versus 7.0%; adjusted odds ratio [OR], 4.93; 95% confidence interval [CI], 2.16–11.25; p<0.001) [11]. In contrast, our findings showed that the preoperative use of antiplatelet agents (OR, 1.244; 95% CI, 0.222–6.975; p=0.804) or anticoagulants (OR, 2.368; 95% CI, 0.432–12.991; p=0.321) was not significantly associated with postoperative major bleeding. Additionally, we examined the relationships of major complications with baseline characteristics and patient status prior to UPCT. As detailed in Table 4, no significant risk factors for major bleeding during tracheostomy were identified.

Our study had several limitations. First, it was retrospective in nature. Second, the patient population was limited to a single hospital, potentially introducing selection bias. Despite these constraints, we believe this study contributes valuable insights to a field in which research on the complications of UPCT is otherwise scarce. Further investigation is essential to more fully assess the safety and complication rates of UPCT; however, our findings suggest that UPCT can be conducted relatively safely in critically ill patients.

Author contributions

Conceptualization: HOP. Data curation: YHL, DHK. Formal analysis: HOP, YHL. Funding acquisition: HOP, YHL. Investigation: HOP, YHL. Methodology: HOP, YHL. Project administration: HOP, YHL. Resources: HOP, YHL. Software: HOP, YHL. Supervision: HOP, YHL. Validation: HOP, YHL. Visualization: HOP, YHL, DHK. Writing–original draft: HOP, YHL, DHK. Writing–review & editing: HOP, YHL. Approval of final manuscript: all authors.

Conflict of interest

No potential conflict of interest relevant to this article was reported.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Acknowledgments

We acknowledge the outstanding contributions of the technicians and nursing staff at Gyeongsang National University Hospital.