Jet ventilation in obese patients undergoing airway surgery for subglottic and tracheal stenosis

Endoscopic treatment of subglottic stenosis with flexible bronchoscopy via laryngeal mask airway

OBJECTIVE

To evaluate the safety and efficacy of endoscopic treatment of subglottic stenosis with flexible bronchoscopy via laryngeal mask airway (LMA) approach.

METHODS

The records of all patients who underwent endoscopic surgery for subglottic stenosis (SGS) from November 2019 to January 2023 at an academic medical center were reviewed with attention to demographics, patient comorbidities, airway stenosis characteristics, operative time details, surgical complications, and post-operative course. All patients, >18 years old, with one or more surgeries for SGS using (LMA) for intraoperative airway management were included. Surgeries with suspension microlaryngoscopy were excluded. Patients with glottic stenosis or tracheotomy were excluded.

RESULTS

Thirty-five patients underwent 52 procedures meeting inclusion criteria. Mean age was 55 years (range 31-78, SD 13.3) and 33 patients (94%) were female. Mean BMI was 30.9 (range 18.4-60.5, SD 8.8). The most common etiology of stenosis was intubation injury in 17 patients (49%), followed by idiopathic in 13 patients (37%). Cotton-Meyer grade 3 (71-99% narrowing) was seen in 25 patients (71%). Mean anesthesia and surgical operative times were 75.9 min (SD 13.5 min) and 39.7 min (SD 11.0 min), respectively. Mean SpO2 nadir was 94.5% (SD 6.3%). No patients required intraoperative change to rigid laryngoscopy, intubation, or tracheotomy. There were no post-operative complications. Mean surgery-free interval was 12.2 months (SD 6.3).

CONCLUSION

Endoscopic treatment of subglottic stenosis with flexible bronchoscopy and spontaneous ventilation via LMA approach is a safe and effective option, especially in patients with limitations for rigid laryngoscopy and elevated BMI.

LEVEL OF EVIDENCE

Level Four (case series) Laryngoscope, 134:2672-2677, 2024.

Comparison of Hemodynamics in Jet Ventilation vs. Intermittent Apnea for Airway Stenosis Surgery

OBJECTIVE

The objective of this study is to assess the impact of two different ventilation techniques, jet ventilation and apneic anesthesia with intermittent ventilation (AAIV), on patient hemodynamics and operative time during endoscopic laryngotracheal stenosis surgery.

METHODS

Retrospective chart review of patients who underwent airway dilation for laryngotracheal stenosis by a single surgeon at a single institution from October 1, 2000 through January 2, 2020. Logistic regression, Mann-Whitney U tests and chi square analysis were used to determine statistical significance.

RESULTS

A total of 157 patients, 43 (27.4%) male and 114 (72.6%) female, and 605 total encounters were included for analysis. There were no significant differences in hemodynamic outcomes when comparing the AAIV and jet ventilation groups. Specifically, there was no significant difference in either peak end-tidal CO2 or nadir O2 saturation between the AAIV and jet ventilation groups (p = 0.4016) and (p = 0.1357), respectively. The patients in the AAIV group had a significantly higher median BMI 32.93 (27.40-39.40) compared with 28.80 (24.1-32.65) (p = 0.0001). Although not necessarily clinically significant, patients with higher BMI had lower median O2 nadirs (97.8%) than non-obese patients (99.2%) (p < 0.0001). The median total procedure time was equivalent when comparing the two ventilation techniques.

CONCLUSION

AAIV is a safe method of ventilation for patients undergoing endoscopic laryngotracheal stenosis surgery with no significant differences in patient hemodynamics or procedure time when compared with jet ventilation. AAIV was the preferred method of ventilation for obese patients undergoing endoscopic laryngotracheal stenosis surgery.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:1343-1348, 2024.

Surgical Management of Airway Stenosis During Pregnancy: A Scoping Review

OBJECTIVE

There are several options for surgical management of subglottic stenosis, including endoscopic and open procedures. However, treatment algorithms, outcomes, and anesthetic management of subglottic stenosis during pregnancy are not well described.

DATA SOURCES

MEDLINE, EMBASE, and the Cochrane databases.

REVIEW METHODS

A scoping review of management of subglottic stenosis during pregnancy was performed, and then reported in compliance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Inclusion criteria consisted of those with subglottic or tracheal stenosis aged greater than 18 years, those in whom management was performed during pregnancy, and those who reported delivery related outcomes.

RESULTS

After systematic review and detailed search of 330 identified articles, 15 articles met inclusion criteria and were included in the final analysis. All studies were case reports or case series (level 4 evidence). This study identified 27 patients. The median age was 29 and the median gestational age at intervention was 28 weeks. Left lateral positioning and fetal heart rate monitoring were used in nearly every case. The most common intervention performed was endoscopic balloon dilation. In many cases, jet ventilation or transnasal humidified rapid insufflation ventilatory exchange was satisfactory for maintenance of the airway. Three women ultimately required tracheostomy prior to labor and delivery. There was no fetal death or complications reported in these studies, and all but one woman proceeded to deliver at term.

CONCLUSION

Endoscopic balloon dilation during pregnancy is safe and effective, resulting in optimized respiratory outcomes for the mother and safe delivery of the fetus. The third trimester appears to be safe for airway intervention. Laryngoscope, 134:1014-1022, 2024.

Unveiling the Success of Awake Insertion of Supraglottic Airway Device for Ventilation in the Bronchoscopic Management of Tracheal Stenosis

Tracheal and subglottic stenoses are inflammatory conditions that can arise from a variety of potential etiologies, most commonly as a result of iatrogenic airway injury due to endotracheal intubation. Significant stenosis requires management by endoscopy or surgical resection. We describe a case of recurrent subglottic cuff stenosis with an episode of sudden desaturation in a 25-year-old female. The management involved balloon dilatation, laser ablation, and topical mitomycin C application through a flexible fiberoptic bronchoscope. Ensuring safe gas exchange during bronchoscopy was a priority, and this was achieved by maintaining ventilation with a supraglottic airway device, which was inserted in an awake patient after adequate tropicalization of the oral cavity. The intervention successfully helped in the management of stenosis and also addressed the complication of sudden complete airway collapse due to sedation.

Anesthesia considerations during management of airway stenosis: A systematic review

OBJECTIVE

To determine the efficacy of ventilatory techniques by evaluating prevalence of technique failure and intraoperative hypoxia during endoscopic management of airway stenosis.

DATA SOURCES

A systematic review was conducted using PubMed and Embase for anesthesia techniques in endoscopic management of airway stenosis.

REVIEW METHODS

The primary outcome measured was reports of partial and complete technique failure. The secondary outcome measured was intraoperative hypoxia.

RESULTS

We identified 7704 abstracts with 17 meeting criteria for analysis. The reported partial and complete ventilatory technique failures were: 0 % Evone Flow-Controlled Ventilation with Tritube endotracheal tube, 0 % laryngeal mask airway, 0 % nonocclusive balloon dilator, 4.76 % spontaneous respiration using intravenous anesthesia and Hi-flow nasal oxygen, and 30.24 % jet ventilation. The reported rate of intraoperative hypoxia was: 0 % Evone Flow-Controlled Ventilation with Tritube endotracheal tube, 0 % spontaneous respiration using intravenous anesthesia and Hi-flow nasal oxygen, 2.18 % jet ventilation, 3.57 % laryngeal mask airway, and 5 % nonocclusive balloon dilator.

CONCLUSION

Evone Flow-Controlled Ventilation with Tritube endotracheal tube had the lowest risk of technique failure and intraoperative hypoxia. Nonocclusive balloon dilator and laryngeal mask airway were also favorable techniques for ventilation. Jet ventilation showed a lower rate of intraoperative hypoxia, but a higher rate of failure. Newer techniques, such as Evone Flow-Controlled Ventilation with Tritube, nonocclusive balloon dilator and spontaneous respiration using intravenous anesthesia and Hi-flow nasal oxygen, may offer promise compared to older techniques like jet ventilation; however, larger studies with more uniform data are needed to determine their efficacy.

Low Pressure Low Frequency Jet Ventilation: Techniques, Safety and Complications

OBJECTIVE

Manual jet ventilation is a specialized oxygenation and ventilation technique that is not available in all facilities due to lack of technical familiarity and fear of complications. The objective is to review our center's 15 year experience with low pressure low frequency jet ventilation (LPLFJV).

METHODS

Retrospective review of procedures utilizing LPLFJV from 2005 to 2019 were performed collecting patient demographic, surgery type and complications. Fisher exact test, Chi square, and t-test were used to determine statistical significance.

RESULTS

Four hundred fifty-seven patients underwent a total of 891 microlaryngeal surgeries-279 cases for voice disorders, 179 for lesions, and 433 for airway stenosis. The peak jet pressure for all cases did not exceed 20 psi and average peak pressure for the last 100 procedures in this case series was 14.9 ± 4.6 psi. The average lowest oxygen saturation for all cases was 95% ± 0.6%. Brief intubation was required in 154 cases (17%). Surgical duration was significantly longer for cases requiring intubation P < .001. The need for intubation was not associated with smoking or cardiopulmonary disease, but was strongly associated with body mass index (BMI). Intubation rates were 7% for normal weight (BMI < 25, N = 216), 13% for overweight (BMI 25-30, N = 282), 24% for obese (BMI 30-40, N = 342), and 37% for morbidly obese (BMI > 40, N = 52) patients. Three patients developed respiratory distress in the recovery unit and 2 patients required intubation.

CONCLUSION

LPLFJV assisted by intermittent endotracheal intubation is an exceedingly safe and effective intraoperative oxygenation and ventilationmodality for a broad variety of laryngeal procedure.

Aerosol Generation During Laryngology Procedures in the Operating Room

OBJECTIVE

Severe acute respiratory syndrome coronavirus-2 spreads through respiratory fluids. We aim to quantify aerosolized particles during laryngology procedures to understand their potential for transmission of infectious aerosol-based diseases.

STUDY DESIGN

Prospective quantification of aerosol generation.

METHODS

Airborne particles (0.3-25 μm in diameter) were measured during live-patient laryngology surgeries using an optical particle counter positioned 60 cm from the oral cavity to the surgeon's left. Measurements taken during the procedures were compared to baseline concentrations recorded immediately before each procedure. Procedures included direct laryngoscopy with general endotracheal anesthesia (GETA), direct laryngoscopy with jet ventilation, and carbon dioxide (CO₂ ) laser use with or without jet ventilation, all utilizing intermittent suction.

RESULTS

Greater than 99% of measured particles were 0.3 to 1.0 μm in diameter. Compared to baseline, direct laryngoscopy was associated with a significant 6.71% increase in cumulative particles, primarily 0.3 to 1.0 μm particles (P < .0001). 1.0 to 25 μm particles significantly decreased (P < .001). Jet ventilation was not associated with a significant change in cumulative particles; when analyzing differential particle sizes, only 10 to 25 μm particles exhibited a significant increase compared to baseline (+42.40%, P = .002). Significant increases in cumulative particles were recorded during CO₂ laser use (+14.70%, P < .0001), specifically in 0.3 to 2.5 μm particles. Overall, there was no difference when comparing CO₂ laser use during jet ventilation versus GETA.

CONCLUSIONS

CO₂ laser use during laryngology surgery is associated with significant increases in airborne particles. Although direct laryngoscopy with GETA is associated with slight increases in particles, jet ventilation overall does not increase particle aerosolization.

LEVEL OF EVIDENCE

III Laryngoscope, 2021.

Jet flow rate and needle position govern distal airway pressures during low-frequency jet ventilation

OBJECTIVES

Although jet ventilation is frequently used during surgery for airway stenosis, little is known about distal airway pressures during jet ventilation. The objective of the study is to determine how jet pressure, flow rate, and position of the ventilation needle relate to distal airway pressure magnitude and homogeneity.

METHODS

Two 3D models of the first five generations of the human airway tree were created. One is a duplicate of a human airway from a 15-year-old healthy male's computed tomography scan, and the other is an idealized symmetric model of human lung morphometry. Pressure transducers measured fifth-generation distal airway pressures in both models. A computer-controlled jet needle positioning system was used to ventilate the lung casts. The effects of jet needle position, jet pressure, and jet flow rate on distal airway pressure and homogeneity were measured.

RESULTS

Total entrained jet flow rate was the most reliable predictor of distal airway pressure. Pressure supplied to the jet ventilation needle had a positive linear relationship with distal airway pressure; however, this relationship was dependent on the jet needle flow resistance. As the ventilation needle moved closer to the tracheal wall, ventilation homogeneity decreased. Depth into the trachea was positively correlated with sensitivity of the needle to the tracheal wall.

CONCLUSION

In this model, total entrained jet flow rate is a more robust predictor of distal airway pressure than jet inlet pressure. More homogeneous ventilation was observed in our model with the ventilation needle centered in the proximal region of the trachea.

Multi-Institutional Analysis of Outcomes in Supraglottic Jet Ventilation with a Team-Based Approach

OBJECTIVES/HYPOTHESIS

To evaluate the safety and complications of endoscopic airway surgery using supraglottic jet ventilation with a team-based approach.

STUDY DESIGN

Retrospective cohort study.

METHODS

Subjects at two academic institutions diagnosed with laryngotracheal stenosis who underwent endoscopic airway surgery with jet ventilation between January 2008 and December 2018 were identified. Patient characteristics (age, gender, race, follow-up duration) and comorbidities were extracted from the electronic health record. Records were reviewed for treatment approach, intraoperative data, and complications (intraoperative, acute postoperative, and delayed postoperative).

RESULTS

Eight hundred and ninety-four patient encounters from 371 patients were identified. Intraoperative complications (unplanned tracheotomy, profound or severe hypoxic events, barotrauma, laryngospasm) occurred in fewer than 1% of patient encounters. Acute postoperative complications (postoperative recovery unit [PACU] rapid response, PACU intubation, return to the emergency department [ED] within 24 hours of surgery) were rare, occurring in fewer than 3% of patient encounters. Delayed postoperative complications (return to the ED or admission for respiratory complaints within 30 days of surgery) occurred in fewer than 1% of patient encounters. Diabetes mellitus, active smoking, and history of previous tracheotomy were independently associated with intraoperative, acute, and delayed complications.

CONCLUSIONS

Employing a team-based approach, jet ventilation during endoscopic airway surgery demonstrates a low rate of complications and provides for safe and successful surgery.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 2021.

The Effects of Laryngoscope Shape and Needle Position on Distal Airway Pressure in Jet Ventilation

OBJECTIVES

Laryngoscopes and subglottiscopes of multiple shapes and lengths are used in airway surgery to maintain an open airway; protect the trachea; and provide a place to mount the light, evacuator, and ventilation needle. Despite differences in scopes and ventilation needle mounting positions, the same jet pressures are typically used. We hypothesized that different scopes and scope configurations would affect distal airway pressure magnitude and homogeneity.

STUDY DESIGN

A laboratory investigation of distal airway pressures in a lung modelduring low frequency jet ventilation.

METHODS

A three-dimensional airway model based on the computed tomography scan of a 15-year old healthy male was fabricated with pressure transducers at the fifth airway generation. A laryngoscope and a subglottiscope were each mounted in the model coaxial with the trachea. Parameters including scope depth and needle mounting position were adjusted, and the effects on distal airway pressure were recorded.

RESULTS

Changing the scope depth from 1 to 3 cm past the laryngeal inlet had a limited effect on distal airway pressure. Needle mounting angle in the laryngoscope strongly influenced distal airway pressure, with a 7° angle change yielding a 67.5% increase. Compared to a loose needle centered in the trachea 1 cm past the laryngeal inlet, the subglottiscope and laryngoscope showed up to 16% and 150% increases in distal airway pressure, respectively.

CONCLUSION

Different scopes or changes in the configuration, such as the needle angle, strongly influence distal airway pressure. Our findings indicate that different jet pressures are required for different scopes and that a stable needle mount is a critical design consideration to prevent changes in minute ventilation due to needle movement.

LEVEL OF EVIDENCE

NA (Basic Research) Laryngoscope, 131:E354-E357, 2021.

Jet Ventilation in the Pregnant Patient with Airway Stenosis: Surgical Safety and Outcomes

OBJECTIVE

To review pregnancy outcomes and the safety of jet ventilation use in the gravid patient undergoing surgical airway intervention.

METHODS

A multi-institutional retrospective review of medical records was performed to identify women who underwent low-frequency jet ventilation during pregnancy for surgical treatment of airway stenosis. Postoperative complications were noted, and patients were interviewed regarding pregnancy outcomes.

RESULTS

Six women were included in this series. No immediate complications relating to anesthesia or surgical intervention were noted in five of the six women. One patient with a well-known history of uncontrolled seizures experienced seizure activity postoperatively. One patient returned to the operating room at a later date for debridement of tracheal crusts. Five mothers delivered via cesarean section and one via spontaneous vaginal delivery. The mean gestation age was 37.3 weeks. One of the six infants delivered prematurely and three were delivered at low birth weight. Three of the six infants required elevated care immediately post-delivery but, at present, all are in good health.

CONCLUSION

Low-frequency jet ventilation and surgical management of airway stenosis should be recognized as a safe treatment option in the gravid patient. Surgical intervention should not be delayed in patients with severe symptoms, particularly given the potential risk associated with prolonged corticosteroid use.

LEVEL OF EVIDENCE

4.

Supraglottic jet oxygenation and ventilation for obese patients under intravenous anesthesia during hysteroscopy: a randomized controlled clinical trial

Background

Supraglottic jet oxygenation and ventilation (SJOV) can effectively maintain adequate oxygenation in patients with respiratory depression, even in apnea patients. However, there have been no randomized controlled clinical trials of SJOV in obese patients. This study investigated the efficacy and safety of SJOV using WEI Nasal Jet tube (WNJ) for obese patients who underwent hysteroscopy under intravenous anesthesia without endotracheal intubation.

Methods

A single-center, prospective, randomized controlled study was conducted. The obese patients receiving hysteroscopy under intravenous anesthesia were randomly divided into three groups: Control group maintaining oxygen supply via face masks (100% oxygen, flow at 6 L/min), the WNJ Oxygen Group with WNJ (100% oxygen, flow: 6 L/min) and the WNJ SJOV Group with SJOV via WNJ [Jet ventilator working parameters:100% oxygen supply, driving pressure (DP) 0.1 MPa, respiratory rate; (RR): 15 bpm, I/E; ratio 1:1.5]. SpO₂, P_ETCO₂, BP, HR, ECG and BIS were continuously monitored during anesthesia. Two-Diameter Method was deployed to measure cross sectional area of the gastric antrum (CSA-GA) by ultrasound before and after SJOV in the WNJ SJOV Group. Episodes of SpO₂ less than 95%, P_ETCO₂ less than 10 mmHg, depth of WNJ placement and measured CSA-GA before and after jet ventilation in the WNJ SJOV Group during the operation were recorded. The other adverse events were collected as well.

Results

A total of 102 patients were enrolled, with two patients excluded. Demographic characteristics were similar among the three groups. Compared with the Control Group, the incidence of P_ETCO₂ < 10 mmHg, SpO₂ < 95% in the WNJ SJOV group dropped from 36 to 9% (P = 0.009),from 33 to 6% (P = 0.006) respectively,and the application rate of jaw-lift decreased from 33 to 3% (P = 0.001), and the total percentage of adverse events decreased from 36 to 12% (P = 0.004). Compared with the WNJ Oxygen Group, the use of SJOV via WNJ significantly decreased episodes of SpO₂ < 95% from 27 to 6% (P = 0.023), P_ETCO₂ < 10 mmHg from 33 to 9% (P = 0.017), respectively. Depth of WNJ placement was about 12.34 cm in WNJ SJOV Group. There was no significantly difference of CSA-GA before and after SJOV in the WNJ SJOV Group (P = 0.234). There were no obvious cases of nasal bleeding in all the three groups.

Conclusions

SJOV can effectively and safely maintain adequate oxygenation in obese patients under intravenous anesthesia without intubation during hysteroscopy. This efficient oxygenation may be mainly attributed to supplies of high concentration oxygenation to the supraglottic area, and the high pressure jet pulse providing effective ventilation. Although the nasal airway tube supporting collapsed airway by WNJ also plays a role. SJOV doesn’t seem to increase gastric distension and the risk of aspiration. SJOV can improve the safety of surgery by reducing the incidence of the intraoperative involuntary limbs swing, hip twist and cough.

Trial registration

Chinese Clinical Trial Registry. Registration number, ChiCTR1800017028, registered on July 9, 2018.