Anesthetic considerations for bronchoscopic procedures: a narrative review based on the Cleveland Clinic experience

Clinical Approach to Central Airway Obstruction in Adult Patients: Perioperative Focus on Causes and Management Including Tracheobronchial Stenting

Central airway obstruction (CAO) is a life-threatening condition associated with poor prognosis. Therapeutic bronchoscopy along with systemic therapies significantly improve survival and quality of life in patients with symptomatic benign and malignant CAO. Endoluminal therapies and tracheobronchial stenting may be used, and a multidisciplinary approach is essential for holistic management of CAO. Perioperative planning and evaluation, as well as attention to intraoperative and postoperative management are key to optimal outcomes. This review provides an overview of the etiology and clinical approach to CAO, perioperative considerations for endoluminal therapies and tracheobronchial stenting, perioperative evaluation and preparation for therapeutic bronchoscopy, and management of operative and postoperative challenges in CAO.

Sedation during dynamic bronchoscopy for expiratory central airway collapse: Which is the ideal protocol?

OBJECTIVE

To compare sedation protocols for dynamic bronchoscopy (DB) in the evaluation of expiratory central airway collapse (ECAC).

MATERIALS AND METHODS

This observational study included adult patients (≥18 years) referred to Mayo Clinic, Jacksonville, FL, from March 2023 to July 2024, for suspected ECAC. Patients were grouped based on sedation protocols: propofol (Protocol 1), remimazolam (Protocol 2), and remimazolam/fentanyl (Protocol 3). The primary outcome was the quality of assessment during DB, rated on a 4-point Likert scale (1 = poor, 4 = excellent). Secondary outcomes included anesthesia duration and post-anesthesia care unit (PACU) length of stay. Statistical analyses included Fisher's exact test, ordinal logistic regression, and Kruskal-Wallis tests.

RESULTS

Seventy-three patients met the inclusion criteria. Overall, DB quality of assessment was significantly associated with sedation protocol (P=0.01 Ordinal regression results suggest that protocol 3 (remimazolam/fentanyl) may be comparable to protocol 1 (propofol) (OR0.40, 95%CI 0.12-1.33, P = 0.13), with both showing a tendency for better performance than protocol 2 (remimazolam) (OR0.14, 95%CI 0.04-0.46 P=0.002 vs protocol 3; OR0.35, 95%CI 0.09-0.29 P=0.115 vs protocol 1). No significant differences were found in PACU length of stay among the three protocols (P = 0.13). No post-procedural complications were reported.

CONCLUSION

Protocol 3 (remimazolam/fentanyl) demonstrated significantly higher odds of achieving a better quality of assessment compared to Protocol 2 (remimazolam) and showed comparable performance to Protocol 1 (propofol). These findings suggest that remimazolam/fentanyl is an effective sedation option for DB, providing improved assessment quality without increasing PACU stay. Larger prospective studies are necessary to confirm these results.

Unveiling the impact of airways: A comparative analysis of oropharyngeal and nasopharyngeal airways in painless fiberoptic bronchoscopy

Background

This study compared the efficacy of oropharyngeal airways (OA) and nasopharyngeal airways (NA) in maintaining oxygenation during painless fiberoptic bronchoscopy (PFB) in patients sedated with remimazolam besylate.

Methods

Two hundred and fifty-two patients were randomized to the OA or NA group. Remimazolam besylate was used for anesthesia induction and maintenance in both groups. We measured and recorded several physiological parameters, including mean arterial pressure, heart rate and oxygen saturation (SpO2), at various time points: before anesthesia (T1), after anesthesia induction (T2), immediately after the bronchoscope reached the trachea (T3), during the procedure (T4), and 5 min after transfer to the post-anesthesia care unit (T5). The incidence and frequency of hypoxemia, minimum SpO2 during the procedure and patient awakening time after flumazenil administration were also recorded. Additionally, the relationship between minimum SpO2 and body mass index (BMI) was investigated.

Results

Patients in the NA group experienced a higher incidence of hypoxemia compared to the OA group. Patients in the OA group maintained higher SpO2 levels at T3 and had a higher minimum SpO2 during the procedure than the NA group. Furthermore, a significant negative correlation was observed between minimum SpO2 and BMI. Following flumazenil anesthesia reversal, nearly 97 % of patients awakened within 1 min.

Conclusions

This study suggests that OA may provide a better safety profile than NA by preserving respiratory function during PFB.

Interventional bronchoscopy in lung cancer treatment

Interventional bronchoscopy has seen significant advancements in recent decades, particularly in the context of lung cancer. This method has expanded not only diagnostic capabilities but also therapeutic options. In this article, we will outline various therapeutic approaches employed through either a rigid or flexible bronchoscope in multimodal lung cancer treatment. A pivotal focus lies in addressing central airway obstruction resulting from cancer. We will delve into the treatment of initial malignant changes in central airways and explore the rapidly evolving domain of early peripheral malignant lesions, increasingly discovered incidentally or through lung cancer screening programmes. A successful interventional bronchoscopic procedure not only alleviates severe symptoms but also enhances the patient's functional status, paving the way for subsequent multimodal treatments and thereby extending the possibilities for survival. Interventional bronchoscopy proves effective in treating initial cancerous changes in patients unsuitable for surgical or other aggressive treatments due to accompanying diseases. The key advantage of interventional bronchoscopy lies in its minimal invasiveness, effectiveness and favourable safety profile.

Non-intubated bronchoscopic tracheobronchial surgeries with electroencephalogram-monitored intravenous anesthesia: feasibility and outcomes

Background

Anesthesia remains challenging for bronchoscopic tracheobronchial surgeries (BTS) involving surgical manipulations for central airway obstruction within shared airways. To provide complete airway use through intervention with spontaneous breathing without endotracheal tubes, monitored non-intubated anesthesia has been successfully applied with electroencephalogram-derived monitored total intravenous anesthesia. This study evaluated the feasibility and the outcomes of BTS with monitored non-intubated anesthesia. The factors associated with desaturation and complications were also analyzed.

Methods

Data from patients receiving non-intubated BTS performed between October 2019 and August 2022 were retrospectively collected. Intraoperative results and postoperative outcomes were analyzed.

Results

Data of 92 patients were collected. Supraglottic airways devices and high-flow nasal oxygen were used in 68 and 24 patients respectively. Surgery was successfully completed in 87 patients (94.6%), whereas three patients required conversion to intubation because of substantial bleeding. In total, 11% of patients experienced desaturation [oxygen saturation (SpO2) <90%] for an average of 9 minutes. Unexpected admission to the intensive care unit (ICU) occurred in 12.2% (5/41) of patients from outpatient department and 7.8% (4/51) of hospitalization settings because of high-grade surgical bleeding. With comparable desaturation incidence, tracheal surgery had significantly longer desaturation times (14.5±6.9 min) than bronchial surgeries (5.8±2.6 min) did.

Conclusions

Monitored non-intubated anesthesia with spontaneous breathing is feasible for BTS, with high success rate, few complications, and rapid recovery. High-grade bleeding remains the most unpredictable risk for intraoperative desaturation and postoperative ICU admission, especially in tracheal obstruction cases.

High Tidal Volume, High Positive End Expiratory Pressure and Apneic Breath Hold Strategies (Lung Navigation Ventilation Protocol) With Cone Beam Computed Tomography Bronchoscopic Biopsy of Peripheral Lung Lesions: Results in 100 Patients

BACKGROUND

A dedicated anesthesia protocol for bronchoscopic lung biopsy-lung navigation ventilation protocol (LNVP)-specifically designed to mitigate atelectasis and reduce unnecessary respiratory motion, has been recently described. LNVP demonstrated significantly reduced dependent ground glass, sublobar/lobar atelectasis, and atelectasis obscuring target lesions compared with conventional ventilation.

METHODS

In this retrospective, single-center study, we examine the impact of LNVP on 100 consecutive patients during peripheral lung lesion biopsy. We report the incidence of atelectasis using cone beam computed tomography imaging, observed ventilatory findings, anesthesia medications, and outcomes, including diagnostic yield, radiation exposure, and complications.

RESULTS

Atelectasis was observed in a minority of subjects: ground glass opacity atelectasis was seen in 30 patients by reader 1 (28%) and in 18 patients by reader 2 (17%), with good agreement between readers (κ = 0.78). Sublobar/lobar atelectasis was observed in 23 patients by reader 1 and 26 patients by reader 2, also demonstrating good agreement (κ = 0.67). Atelectasis obscured target lesions in very few cases: 0 patients (0%, reader 1) and 3 patients (3%, reader 2). Diagnostic yield was 85.9% based on the AQuIRE definition. Pathology demonstrated 57 of 106 lesions (54%) were malignant, 34 lesions (32%) were benign, and 15 lesions (14%) were nondiagnostic.

CONCLUSION

Cone beam computed tomography images confirmed low rates of atelectasis, high tool-in-lesion confirmation rate, and high diagnostic yield. LNVP has a similar safety profile to conventional bronchoscopy. Most patients will require intravenous fluid and vasopressor support. Further study of LNVP and other ventilation protocols are necessary to understand the impact of ventilation protocols on bronchoscopic peripheral lung biopsy.

Digital Tomosynthesis: Review of Current Literature and Its Impact on Diagnostic Bronchoscopy

Bronchoscopy has garnered increased popularity in the biopsy of peripheral lung lesions. The development of navigational guided bronchoscopy systems along with radial endobronchial ultrasound (REBUS) allows clinicians to access and sample peripheral lesions. The development of robotic bronchoscopy improved localization of targets and diagnostic accuracy. Despite such technological advancements, published diagnostic yield remains lower compared to computer tomography (CT)-guided biopsy. The discordance between the real-time location of peripheral lesions and anticipated location from preplanned navigation software is often cited as the main variable impacting accurate biopsies. The utilization of cone beam CT (CBCT) with navigation-based bronchoscopy has been shown to assist with localizing targets in real-time and improving biopsy success. The resources, costs, and radiation associated with CBCT remains a hindrance in its wider adoption. Recently, digital tomosynthesis (DT) platforms have been developed as an alternative for real-time imaging guidance in peripheral lung lesions. In North America, there are several commercial platforms with distinct features and adaptation of DT. Early studies show the potential improvement in peripheral lesion sampling with DT. Despite the results of early observational studies, the true impact of DT-based imaging devices for peripheral lesion sampling cannot be determined without further prospective randomized trials and meta-analyses.

Track your trach: Removal of a fractured tracheostomy tube using a flexible fibreoptic bronchoscope in a patient with severe head injury

Tracheostomy is a common airway procedure for life support in critically ill patients with head injuries. This procedure is safe but also associated with early and late complications. Tube fracture and dislodgement into the tracheobronchial tree leading to airway obstruction is a rare but life-threatening complication after prolonged tracheostomy tube placement. There are very few published reports of tracheostomy tube fracture and dislodgement into tracheobronchial tree in a neurologically injured patient. We report a case of a fractured tracheostomy tube which got impacted in the left main bronchus, in a 41-year-old male patient who had been on prolonged tracheostomy tube after craniotomy and evacuation of subdural hematoma. The distal part of the tracheostomy tube fractured and impacted in the left main bronchus. Fibreoptic bronchoscopy was performed through the oral cavity to extract it, and the anaesthetic management during the period is discussed.

Awake Fiberoptic Nasotracheal Intubation and Anesthetic Management of a Patient With a Compressed and Deviated Airway From a Massive Thyroid Goiter: A Case Report

Difficult airway management is a challenge for anesthesiologists, requiring proper assessment, planning, and sometimes a multidisciplinary approach to establish a secure airway. Here we present a case where the patient had a large thyroid goiter with significant tracheal compression. Due to the large size of the thyroid mass and the location of tracheal narrowing, fiberoptic intubation appeared to be challenging, and a surgical airway was not a viable option to obtain a secure airway for a total thyroidectomy. This case report discusses awake fiberoptic intubation and intraoperative anesthetic management of a patient with known airway compression and explores the alternative method for obtaining a definitive airway through venovenous extracorporeal membrane oxygenation.

Evaluation of Supraglottic Jet Oxygenation and Ventilation in 105 Patients During Bronchoscopy Using the Twinstream® Microprocessor-Controlled Jet Ventilator and the Wei Nasal Jet® Tube

BACKGROUND The Twinstream® ventilator is a microprocessor-controlled electric jet ventilator that allows the simultaneous application of 2 different jet streams, one at low frequency and one at high frequency to result in pulsatile bi-level (p-BLV) mode of ventilation. This study aimed to evaluate supraglottic jet oxygenation and ventilation in 105 patients during bronchoscopy using the Twinstream® microprocessor-controlled jet ventilator and the Wei Nasal Jet® (WNJ) tube. MATERIAL AND METHODS Patients were randomly divided into 2 parallel groups (N=50 per group): group W using the WNJ tube and group M using an endoscopic face mask connected to Twinstream® microprocessor-controlled jet ventilator under monitored anesthesia care. Arterial blood gas was examined and recorded 15 minutes after the initiation of procedure. The demographic and clinical characteristics, procedure duration, doses of anesthetics, and adverse events in the 2 groups were also recorded. RESULTS The arterial partial pressure of carbon dioxide (PaCO₂) (P=0.006) and lactic acid (P=0.001) were significantly lower, while pH (P=0.024) was significantly higher than in the group M. Pearson analysis showed that PaCO₂ was significantly correlated with ventilation tools (P=0.006) and procedure duration (P=0.003). Multiple linear regression analysis showed that ventilation tools and procedure duration were both independent influencing factors (P=0.006, P=0.002). CONCLUSIONS Supraglottic jet oxygenation and ventilation using the WNJ tube can reduce PaCO2 and had advantages in enhancing oxygenation and ventilation function in patients during bronchoscopy intervention therapy under monitored anesthesia care.

Severe Central Airway Obstruction Secondary to a Giant Endobronchial Hamartoma: A Case Report

Central airway obstruction refers to the occlusion of more than 50% of the trachea, main stem bronchi, or lobar bronchus. It can potentially become a life-threatening condition. Pulmonary hamartomas (PH) are rare tumors with an incidence of 0.25%, constituting about 8% of all benign lung neoplasms. Only 10% of PH occur endobronchially, while the remaining appear peripherally. We present the case of a women with an endobronchial hamartoma that required emergent resection by bronchoscopy. This is 44-year-old woman, with a history of an endobronchial mass on the right main stem bronchus (RMSB) without histopathological diagnosis or surgical management. She presented with a history of chronic cough and expectoration. Upon admission, a chest X-ray was performed, showing opacities of the right lung and amputations of the RMSB. Bronchoscopy was performed and a tumor-like mass that occludes the RMSB was found, with valve effect causing intermittent occlusion. In anesthetic induction, she presents severe airway obstruction and cardiorespiratory arrest. During resuscitation maneuvers, the lesion that was obstructing the light is seen and resection was performed with electrocautery and cryotherapy probes. Histopathological report described an endobronchial chondromesenchymal hamartoma, with no signs of malignancy. The control X-ray showed adequate re-expansion of the right lung. In conclusion, although endobronchial hamartoma has a low incidence and has a slow growth rate, it can manifest as severe airway obstruction. To achieve a complete resection of an endobronchial lesion, both rigid and/or flexible bronchoscopy plus multimodal interventions are recommended.

Safety of Rigid Bronchoscopy for Therapeutic Intervention at the Intensive Care Unit Bedside

Background and Objective: Although rigid bronchoscopy is generally performed in the operating room (OR), the intervention is sometimes emergently required at the intensive care unit (ICU) bedside. The aim of this study is to evaluate the safety of rigid bronchoscopy at the ICU bedside. Materials and Methods: We retrospectively analyzed medical records of patients who underwent rigid bronchoscopy while in the ICU from January 2014 to December 2020. According to the location of rigid bronchoscopic intervention, patients were classified into the ICU group (n = 171, cases emergently performed at the ICU bedside without anesthesiologists) and the OR group (n = 165, cases electively performed in the OR with anesthesiologists). The risk of intra- and post-procedural complications in the ICU group was analyzed using multivariable logistic regression, with the OR group as the reference category. Results: Of 336 patients, 175 (52.1%) were moribund and survival was not expected without intervention, and 170 (50.6%) received invasive respiratory support before the intervention. The most common reasons for intervention were post-intubation tracheal stenosis (39.3%) and malignant airway obstruction (34.5%). Although the overall rate of intra-procedural complications did not differ between the two groups (86.0% vs. 80.6%, p = 0.188), post-procedural complications were more frequent in the ICU group than in the OR group (24.0% vs. 12.1%, p = 0.005). Severe complications requiring unexpected invasive management occurred only post-procedurally and were more common in the ICU group (10.5% vs. 4.8%, p = 0.052). In the fully adjusted model, the ICU group had increased odds for severe post-procedural complications, but statistical significance was not observed (odds ratio, 2.54; 95% confidence interval, 0.73-8.88; p = 0.144). Conclusions: Although general anesthesia is generally considered the gold standard for rigid bronchoscopy, our findings indicate that rigid bronchoscopy may be safely performed at the ICU bedside in selective cases of emergency. Moreover, adequate patient selection and close post-procedural monitoring are required to prevent severe complications.

Anesthesia for interventional pulmonology

PURPOSE OF REVIEW

Anesthesia for pulmonological interventions is a demanding challenge. This article discusses recent innovations and the implications for periinterventional anesthetic management.

RECENT FINDINGS

Interventional pulmonology is a rapidly expanding specialty with very complex diagnostic and therapeutic approaches that include oncological staging, treatment of obstructive and restrictive lung diseases, recanalization of endobronchial obstructions, and retrieval of foreign bodies. With the development of advanced diagnostic and therapeutic interventions, the application is extended to critically ill patients. Current evidence focusing on the anesthetic techniques is presented here.

SUMMARY

The development of new pulmonological methods requires a tailored anesthesiological approach. Their specific impact must be taken into account to ensure patient safety, goal-oriented outcome diagnostics and -quality, successful interventions, and patient comfort.

Risk factors for anesthetic-related complications in pediatric patients with a newly diagnosed mediastinal mass

BACKGROUND

Pediatric patients with a mediastinal mass can experience severe complications while undergoing anesthesia. Nearly, all published reviews involve either patients with an anterior mediastinal mass or patients with an oncologic disease.

AIM

The identification of risk factors for anesthetic-related complications in pediatric patients with any type of mediastinal mass.

METHODS

From January 1, 2008 to December 31, 2019, patients with a newly diagnosed mediastinal mass that underwent anesthesia were retrospectively identified. Each patient's medical record was reviewed for presenting symptoms, preprocedure imaging results, the type of anesthetic delivered, and the occurrence of any anesthetic-related complications. A complication was defined as severe hypoxia, severe hypotension, or loss of endtidal carbon dioxide.

RESULTS

Eighty-six patients presented with a new mediastinal mass. Six of these patients (7%) had a complication. Complications were no more likely in patients with orthopnea than in patients without orthopnea (P = 1.00; relative risk (RR) = 0.95; 95% CI (0.1, 7.5). Complication rates in patients with anterior, middle, and posterior mediastinal masses were similar, as were complication rates in patients with large, medium, and small masses. Six of the 41 patients (15%) who had tracheal compression had a complication, while none of the 45 patients (0%) who did not have tracheal compression had a complication (p = .0096). Six of the 48 patients (13%) that were intubated had a complication, while none of the 38 patients (0%) who were not intubated had a complication (p = .032). Five of 36 patients (14%) who had mainstem bronchus compression had a complication, while one of 50 patients (2%) who did not have mainstem bronchus compression had a complication (p = .078; RR = 6.9l; 95% CI (0.8, 56.9)).

CONCLUSIONS

Anesthetic-related complications were associated with airway compression and endotracheal intubation. The absence of preprocedure orthopnea did not ensure that the anesthetic would be uncomplicated. Complications occurred in similar frequencies in patients with a mediastinal mass of any location or size.

Anesthesia considerations to reduce motion and atelectasis during advanced guided bronchoscopy

Partnership between anesthesia providers and proceduralists is essential to ensure patient safety and optimize outcomes. A renewed importance of this axiom has emerged in advanced bronchoscopy and interventional pulmonology. While anesthesia-induced atelectasis is common, it is not typically clinically significant. Advanced guided bronchoscopic biopsy is an exception in which anesthesia protocols substantially impact outcomes. Procedure success depends on careful ventilation to avoid excessive motion, reduce distortion causing computed tomography (CT)-to-body-divergence, stabilize dependent areas, and optimize breath-hold maneuvers to prevent atelectasis. Herein are anesthesia recommendations during guided bronchoscopy. An FiO₂ of 0.6 to 0.8 is recommended for pre-oxygenation, maintained at the lowest tolerable level for the entire the procedure. Expeditious intubation (not rapid-sequence) with a larger endotracheal tube and non-depolarizing muscle relaxants are preferred. Positive end-expiratory pressure (PEEP) of up to 10-12 cm H₂O and increased tidal volumes help to maintain optimal lung inflation, if tolerated by the patient as determined during recruitment. A breath-hold is required to reduce motion artifact during intraprocedural imaging (e.g., cone-beam CT, digital tomosynthesis), timed at the end of a normal tidal breath (peak inspiration) and held until pressures equilibrate and the imaging cycle is complete. Use of the adjustable pressure-limiting valve is critical to maintain the desired PEEP and reduce movement during breath-hold maneuvers. These measures will reduce atelectasis and CT-to-body divergence, minimize motion artifact, and provide clearer, more accurate images during guided bronchoscopy. Following these recommendations will facilitate a successful lung biopsy, potentially accelerating the time to treatment by avoiding additional biopsies. Application of these methods should be at the discretion of the anesthesiologist and the proceduralist; best medical judgement should be used in all cases to ensure the safety of the patient.

Safety application of muscle relaxants and the traditional low-frequency ventilation during the flexible or rigid bronchoscopy in patients with central airway obstruction: a retrospective observational study

Background

Bronchoscopy treatments of central airway obstruction (CAO) under general anesthesia are high-risky procedures, and posing a giant challenge to the anesthesiologists. We summarized and analyzed our clinical experience in patients with CAO undergoing flexible or rigid bronchoscopy, to estimate the safety of skeletal muscle relaxants application and the traditional Low-frequency ventilation.

Methods

Clinical data of 375 patients with CAO who underwent urgent endoscopic treatments in general anesthesia from January 2016 to October 2019 were retrospectively reviewed. The use ratio of skeletal muscle relaxants, dose of skeletal muscle relaxants used, the incidence of perioperative adverse events, adequacy of ventilation and gas exchange, post-operative recovery between rigid bronchoscopy and flexible bronchoscopy therapy, and risk factors for postoperative ICU admission were evaluated.

Results

Of the 375 patients with CAO, 204 patients were treated with flexible bronchoscopy and 171 patients were treated with rigid bronchoscopy. Muscle relaxants were used in 362 of 375 patients (including 313 cisatracurium, 45 rocuronium, 4 atracurium, and 13 unrecorded). The usage rate of muscle relaxants (96.5% in total) was very high in patients with CAO who underwent either flexible bronchoscopy (96.6%) or rigid bronchoscopy (96.5%) therapy. The dosage of skeletal muscle relaxants (Cisatracium) used was higher in rigid bronchoscopy compared with flexible bronchoscopy therapy (10.8 ± 3.8 VS 11.6 ± 3.6 mg, respectively, p < 0.05). No patient suffered the failure of ventilation, bronchospasm and intraoperative cough either in flexible or rigid bronchoscopy therapy. Hypoxemia was occurred in 13 patients (8 in flexible, 5 in rigid bronchoscopy) during the procedure, and reintubation after extubation happened in 2 patients with flexible bronchoscopy. Sufficient ventilation was successfully established using the traditional Low-frequency ventilation with no significant carbon dioxide accumulation and hypoxemia occurred both in flexible and rigid bronchoscopy group (p > 0.05). Three patients (1 in flexible and 2 in rigid) died, during the post-operative recovery, and the higher grade of American Society of Anesthesiologists (ASA) and obvious dyspnea or orthopnea were the independent risk factors for postoperative ICU admission.

Conclusion

The muscle relaxants and low-frequency traditional ventilation can be safely used both in flexible and rigid bronchoscopy treatments in patients with CAO. These results may provide strong clinical evidence for optimizing the anesthesia management of bronchoscopy for these patients.

High frequency jet ventilation through mask contributes to oxygen therapy among patients undergoing bronchoscopic intervention under deep sedation

Background

High frequency jet ventilation (HFJV) is an open ventilating technique to maintain ventilation for emergency or difficult airway. However, whether jet ventilation or conventional oxygen therapy (COT) is more effective and safe in maintaining adequate oxygenation, is unclear among patients with airway stenosis during bronchoscopic intervention (BI) under deep sedation.

Methods

A prospective randomized cohort study was conducted to compare COT (high flow oxygen) with normal frequency jet ventilation (NFJV) and HFJV in oxygen supplementation during BI under deep sedation from March 2020 to August 2020. Patients receiving BI under deep sedation were randomly divided into 3 parallel groups of 50 patients each: the COT group (fractional inspired oxygen (FiO₂) of 1.0, 12 L/min), the NFJV group (FiO₂ of 1.0, driving pressure of 0.1 MPa, and respiratory rate (RR) 15 bpm) and the HFJV Group (FiO₂ of 1.0, driving pressure of 0.1 MPa, and RR of 1200 bpm). Pulse oxygen saturation (SpO₂), mean arterial blood pressure and heart rate were recorded during the whole procedure. Arterial blood gas was examined and recorded 15 min after the procedure was initiated. The procedure duration, dose of anesthetics, and adverse events during BI in the three groups were also recorded.

Results

A total of 161 patients were enrolled, with 11 patients excluded. The clinical characteristics were similar among the three groups. PaO₂ of the COT and NFJV groups was significantly lower than that of the HFJV group (P < 0.001). PaO₂ was significantly correlated with ventilation mode (P < 0.001), body mass index (BMI) (P = 0.019) and procedure duration (P = 0.001). Multiple linear regression showed that only BMI and procedure duration were independent influencing factors of arterial blood gas PaO₂ (P = 0.040 and P = 0.002, respectively). The location of airway lesions and the severity of airway stenosis were not statistically correlated with PaCO₂ and PaO₂.

Conclusions

HFJV could effectively and safely improve intra-operative PaO₂ among patients with airway stenosis during BI in deep sedation, and it did not increase the intra-operative PaCO₂ and the risk of hypercapnia. PaO₂ was correlated with ventilation mode, BMI and procedure duration. Only BMI and procedure duration were independent influencing factors of arterial blood gas PaO₂. PaCO₂ was not correlated with any preoperative factor.

Trial registration

Chinese Clinical Trial Registry. Registration number, ChiCTR2000031110, registered on March 22, 2020.