Partial Obstruction of the Endotracheal Tube by a Part of the Metallic Stylet; Case Report and Review of the Literature

Introduction

Partial obstruction of the endotracheal tube by a metallic stylet is a rare and potentially life-threatening complication encountered during intubation procedures.¹ The endotracheal tube is a critical device to secure the airway and facilitate mechanical ventilation in patients undergoing anesthesia or those requiring respiratory support.² While endotracheal intubation is a routine and essential procedure in various medical settings, complications associated with using adjunct devices, such as the metallic stylet, can pose unique challenges to healthcare professionals.³

The metallic stylet is a rigid and flexible instrument commonly employed to aid intubation. Its purpose is to guide the endotracheal tube smoothly into the trachea, ensuring proper placement and effective ventilation.⁴ However, in rare instances, the metallic stylet can become dislodged or mispositioned inside the endotracheal tube, leading to partial airway obstruction.⁵

Difficult airways are commonly encountered in clinical practice, especially in emergencies. Difficulty airway is estimated as 20%, with about 1% failure. Many devices have been used and known in current practice, including the metallic stylet, to facilitate managing the difficult airway and for routine intubation.^5,6

Because this complication is rare and unpredictable, healthcare professionals may not be familiar with its presentation or diagnosis.⁷ Recognizing the signs and symptoms early is crucial for prompt intervention and avoiding adverse outcomes.^8,9

In acute respiratory status deterioration in the pediatric intensive care unit, equipment failure is among the most common causes.^10,11 An obstructed endotracheal tube (ETT) is a common cause of ventilatory or oxygen delivery failure.¹² It is common for the ETT to become obstructed by secretions. Nevertheless, we present a case in which part of the metal stylet obstructs the ETT’s lumen during intubation.¹³

Several case reports and retrospective studies have documented partial obstruction of the endotracheal tube due to the metallic stylet becoming dislodged or malpositioned inside the tube.^14–16 These reports underscore the importance of vigilance during intubation and the need to recognize this rare but critical complication early.

In a study conducted by Sahin et al in 2020, they reported a case of partial endotracheal tube obstruction. Using endotracheal tubes in sick infants may lead to potentially life-threatening airway obstruction. Therefore, inspecting these tubes before use¹⁷ carefully is imperative.

In another study by Kim et al, a series of cases of partial airway obstruction due to dislodged stylets was reviewed. The authors highlighted the unpredictability of this complication and recommended increased awareness among healthcare providers to diagnose and manage it¹⁸ promptly.

Management of partial endotracheal tube obstruction caused by a metallic stylet involves immediate recognition and prompt intervention. O’Connor et al reported the successful resolution of a case by carefully withdrawing the metallic stylet under bronchoscopic guidance, restoring adequate airway patency.⁹ In contrast, Akins et al discussed a case where delayed complication recognition led to severe hypoxemia and necessitated emergent reintubation. The report highlights the importance of regular monitoring and vigilant post-intubation assessments.¹⁹

The significance of this case report lies in its potential to raise awareness among clinicians, anesthesiologists, and critical care teams about the risks associated with using metallic stylets during intubation. Through an in-depth examination of the literature and a critical analysis of similar reported cases, this report aims to contribute to the existing knowledge on this subject and emphasize the importance of vigilant airway management practices.

Herewith, we document the successful treatment of a pediatric patient with respiratory failure due to partial obstruction of the endotracheal tube by a portion of the metal stylet.

Case Report

A two-year-old boy presented with respiratory failure due to covid-19. The patient needed intubation, so he was intubated with a 4.5cc ETT. Intubation was performed in the second attending and with a metal stylet during both attendings. However, we noticed difficulty in removing the stylet. After intubation, the patient maintained his oxygen saturation and had good air entry into both sides of the lungs. Unfortunately, we did not notice that the stylet was slightly short after removal. In the first 6 hours, unexplained short desaturations occurred repeatedly. After intubation, radiography was performed, and it was suspected that there was a remnant in the trachea at the level of the bifurcation. The patient developed pneumothorax, and a chest tube was placed. Then we observed an accumulation of CO2 in the VBGs in the first 6 hours. Suction was performed, and we had difficulty aspirating the endotracheal tube. A chest radiograph showed a foreign body (Stylet’s part) in the tube and trachea (see Figures 1 and 2). We checked the intubation kits and found that a stylet was booked at the end.

Figure 1 Stylet.

Figure 2 Shows a foreign body (Stylet’s part) in the tube and trachea.

The otolaryngology team was called in. The flexible endoscope shows the stylet tip in the trachea. The endotracheal tube was removed, and a rigid bronchoscopy was performed. A stylet was retrieved with telescopic forceps. The patient was easily reintubated after the procedure. After removing that part, the patient’s condition improved regarding ventilation with the same oxygenation issue. After removal, there was an immediate improvement in tidal volumes and peak airway pressures.

Discussion

Partial obstruction of an ETT can lead to significant respiratory compromise and requires prompt intervention to prevent hypoxia and hypercapnia. Using a stylet during intubation can aid in guiding the ETT through the vocal cords, but it should be removed after successful intubation to prevent complications.

Airway obstruction due to a foreign body should be regularly reported. However, medical device involvement is common and results in severe respiratory morbidities.^15–17

Any stylet can lead to such a problem. Either multiple used metallic stylet or coated stylet with plastic. Also, offering stylet can contribute to this problem, or using a single used one for multiple users specifically with lousy quality. Although, few cases were reported with blocked ETT tubes by stylet or any part.^18,19

An earlier report described a child intubated with a stylet at 24 weeks gestational age on the 16th day of life. It required considerable effort by the physician to remove the stylet after intubation. After removing the plastic stylet, the infant’s condition improved dramatically.²⁰ One month after the repair of a bilateral inguinal hernia, an infant experienced the removal of the plastic tip of the stylet, and the stylet was released. There was a case of two large plastic fragments detaching from a stylet when he was intubated at age 27 after trauma. A few hours later, a piece was removed from the endotracheal tube, and the result was satisfactory.^21,22

Multiple other factors can increase these events, like firmly holding the ETT the clinician during the removal of the stylet after intubation or quickly and firmly pulling the stylet out.^23–27 In our case, the cause of this event was using multiple used stylet and a single user.

Increased awareness among healthcare providers is vital to promptly diagnose and manage this complication. The case report and literature review serve as valuable educational tools for healthcare professionals, highlighting the importance of recognizing early signs of airway obstruction and employing appropriate interventions.

Conclusion

A metallic object’s partial obstruction of an ETT can lead to significant respiratory compromise and requires prompt intervention. Using a stylet during intubation can aid in guiding the ETT through the vocal cords, but it should be removed after successful intubation to prevent complications. Proper technique should be used during removal to prevent dislodgement and equipment migration into the ETT lumen.

This case demonstrates that multiple uses of a stylet, especially by a single user, can result in impaction of the stylet in the ETT during intubation, such that an effort to pull the stylet out after intubation can result in breakage, shearing, and entrapment of the stylet or plastic sheath in the lumen of the ETT. Also, checking the equipment before and after intubation, not in quantity base also in quality, it’s important and can prevent this from happening or at least quickly discover it after happening.