Utility of oxygen insufflation through working channel during fiberoptic intubation in apneic patients: a prospective randomized controlled study

Oxygen insufflation via the working channel during tracheal intubation guided by a flexible optical scope and benefits, dangers, and future of the method: a narrative review

When performing tracheal intubation guided by a flexible optical scope, the operator may lose the anatomical orientation and hypoxia may occur. Oxygen insufflation through the working channel of the flexible optical scope is used by anaesthetists to prevent blurring of the lens and to prevent hypoxia. However, fatal iatrogenic injuries from this method are reported. Our aim is to review the current literature on oxygen insufflation through the working channel during tracheal intubation guided by a flexible optical scope, to identify its benefits and the source of its dangers, and ultimately to provide a basis for the development of a safer technique. We conducted a literature search of databases, guidelines, and textbooks using search terms related to oxygen insufflation through the working channel during intubation guided by a flexible optical scope. Clinical trials confirm that the technique results in better visibility and better oxygenation during intubation. Gastric rupture and pneumothorax were the most frequent types of injury. We identified that oxygen insufflation without pressure limitation during accidental misplacement of the flexible optical scope in the oesophagus, deep in the lower airways, or via a tear of the airway mucosa was the cause of barotrauma. We conclude that a delivered pressure below 40 cm H2O will likely carry a low risk of serious adverse outcomes. The technique in its current form seems unsafe, and future research should aim at developing a system that delivers oxygen at pressures respecting gastric and airway physiologic pressure thresholds with a flow sufficient to obtain the documented advantages of the technique.

Optimal Duration of High-Fidelity Simulator Training for Bronchoscope-Guided Intubation: A Noninferiority Randomized Trial

INTRODUCTION

The optimal simulator training duration for flexible optical bronchoscopic (FOB) intubation is unknown. This study aimed to determine whether a learning curve-based training modality was noninferior to a fixed training time modality in terms of clinical FOB intubation time.

METHODS

This multicenter, randomized, noninferiority study was conducted from May to August 2022. Anesthesiology residents or interns were enrolled. Eligible participants were randomized in a 1:1 ratio to receive new learning curve-based simulator training (individualized training time based on performance, group New) or reference fixed training time simulator training (1 hour, group Reference). The primary outcome was the time to complete FOB intubation in patients, which was defined as the time from the introduction of the FOB into the mouth until the first capnography visualization. The margin for detecting clinical significance was defined as 10 seconds.

RESULTS

A total of 32 participants were included in the analysis (16 in each group). All trainees successfully intubated the patients. The mean intubation time (95% confidence interval [CI]) was 81.9 (65.7-98.1) seconds in group New and 97.0 (77.4-116.6) seconds in group Reference. The upper bound of the 1-sided 97.5% CI for the mean difference of clinical intubation time between groups was 9.3 seconds. Noninferiority was claimed. The mean duration of the training in group New was 28.4 (95% CI, 23.5-33.4) minutes. The total number of training procedures on simulators in group New was significantly less than that in group Reference ( P < 0.01).

CONCLUSIONS

The clinical FOB intubation time in group New was noninferior to that in group Reference.

Continuous Positive-Pressure Oxygen Supply Improves Fiberoptic Intubation Efficacy and Safety in Patients With Simulated Cervical Spinal Injury: A Prospective Double-Blind Randomized Controlled Study

BACKGROUND

Fiberoptic intubation is an important method for tracheal intubation in patients with cervical spine injury. How to effectively and safely complete fiberoptic intubation while maintaining the stability of the cervical spine is very important. This study compared the efficiency and safety of fiberoptic intubation after anesthesia induction under different types of air pressure in patients with simulated cervical spinal injury.

METHODS

In total, 59 adult patients who underwent fiberoptic intubation with a cervical collar for simulated cervical spinal injury were randomly allocated to continuous positive-pressure oxygen, normal-pressure, or intermittent negative-pressure suction groups. After the induction of anesthesia and adequate 100% oxygenation, which confirmed effective neuromuscular blockade, it was deemed appropriate to begin fiberoptic intubation. In the continuous positive-pressure oxygen group, the fiberoptic device was connected through the negative-pressure suction path with 5 L/min oxygen. In the intermittent negative-pressure suction group, the fiberoptic device was connected to the negative-pressure suction device. In the normal-pressure group, the flexible fiberoptic device was not connected to either the oxygen source or the negative-pressure suction device. The intubation time was recorded as the primary outcome measure. The intubation success rate, number of attempts, minimum SpO2, objective lens contamination rate, and incidence of complications were also compared among the groups.

RESULTS

Compared with those in the other groups, the median (range) intubation time in the continuous positive-pressure group was 59 (36-181) seconds, which was significantly shorter than that in the normal-pressure group, 167 (46-181) seconds, and the intermittent negative-pressure suction group, 132.5 (38-181) seconds (P=0.04). The success rate of nasotracheal intubation was significantly greater in the continuous positive-pressure group (94.7%, 18/19) than in the normal-pressure group (50%, 10/20) and intermittent negative-pressure suction group (50%, 10/20) (P=0.004). There was a significant difference among the three groups (P=0.043). The median (range) minimum SpO2 during fiberoptic intubation was 100% (99-100%) in the continuous positive-pressure group, 100% (90-100%) in the normal-pressure group, and 99% (88-100%) in the intermittent negative-pressure suction group (P=0.029). However, no statistically significant difference was detected among the groups with complications.

CONCLUSION

The continuous use of positive-pressure oxygen via the negative-pressure suction pathway can improve the efficiency and safety of fiberoptic intubation in patients with simulated cervical spinal injury after anesthesia induction.

Trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) in neuroanesthesia practice: A review

Respiratory management is an important aspect of care in neuroanesthesia practice for neurosurgical patients. A wide variety of procedures are performed under sedation in the neurosurgical population, and maintaining oxygenation is of paramount importance during these procedures. The high-flow oxygen devices improve arterial oxygenation by providing higher inspiratory oxygen concentration and maintaining higher dynamic positive airway pressure. These devices have gained importance during the recent years with regard to enhancing patient safety. This narrative review focuses on the role of trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) and high-flow nasal oxygenation (HFNO) techniques in the neuroanesthesia practice and electroconvulsive therapy.

Clinical application of fiberoptic bronchoscope combined with visual laryngeal mask awake tracheal intubation technique: a case report

We presented a case of successful awake endotracheal intubation in a patient with a giant goiter and severe tracheal stenosis. The patient had difficulty in airway management during the perioperative anesthesia due to tracheal deviation and stenosis caused by tumor compression. We applied a visual laryngeal mask combined with fiberoptic bronchoscope to visualize the whole procedure of endotracheal intubation, from visually assessing the glottic, subglottic, and the tracheal conditions, to evaluating the pressure of the tumor on the trachea and the maximum tracheal tube diameter that could be passed. During the entire process, the patient remained awake, maintained spontaneous breathing, and actively cooperated with the clinical staff. Hence, we demonstrated that this method is safe, effective, operable, and could be generalized as a form of endotracheal intubation for patients with known difficult airways.

Assessing the Degree of Satisfaction, Duration, and Level of Cooperativeness among Patients Undergoing Flexible Bronchoscopy

Background: Bronchoscopy is an invasive procedure that has been used for a long time for diagnostic and therapeutic purposes. Objective: To assess the degree of satisfaction, duration, and level of cooperativeness among patients undergoing flexible fiberoptic bronchoscopy. Methods: The A quasi-experimental study was carried out on 128 flexible bronchoscopy patients that were equally divided into control and study groups. The program was applied only to the study group, and all procedure steps were discussed with patients by video records. The anxiety level score, patient satisfaction, and duration of the procedure were assessed in both groups. Results: The highest age range of patients was 61-90 years, with 38 patients from the study group (59.4%) and 44 from the control group (68.8%). Also, in both groups, most patients were illiterate, non-smokers, from nonduty areas, not city center residents, and had more than one associated comorbidity. The hospital anxiety scale was highly significant in the study group (p=0.0001), and the patient's satisfaction rate in the same group was significant (p=0.001). The procedure duration was significantly shorter in the study group (1.381 minutes) than in the control group. Conclusions: Patients with a better knowledge of the bronchoscopy procedure were more comfortable with the process, and the procedure duration was significantly shorter. Moreover, the process results in minimizing the levels of anxiety and improving the tolerability of the patients.