Laryngeal Surgery as It Pertains to the Thoracic Surgeon

A surgeon managing complex airway disease benefits from knowledge of laryngeal physiology and pathology. The Larynx provides phonation and protection for the lower airway via closure and cough reflex. Disruption of these functions or development of paralysis or stenosis can lead to respiratory failure. Management includes a variety of endoscopic and open management techniques. Understanding of laryngeal physiology can also limit laryngeal functional impairment through careful preservation of motor nerves and early recognition of injuries.

Spontaneous Ventilation With High-Flow Nasal Oxygen for Elective Suspension Microlaryngoscopy

Objective

Spontaneous ventilation under intravenous anesthesia allows the surgeon to work without interruption or obstruction of the operating field during suspension microlaryngoscopy (SML). High-flow nasal oxygen therapy (HFNO) is increasingly used in anesthesia. We hypothesized that its use during SML would increase patient safety even in situations where the airway is compromised by tumor or stenosis.

Study Design

Retrospective observational study.

Setting

University Hospital of Lausanne, Switzerland.

Methods

Adults patients who were scheduled for elective microlaryngeal surgery and managed with HFNO in spontaneous ventilation under general anesthesia between October 2020 and December 2021.

Results

Twenty-seven patients for a total of 32 surgical procedures were performed under HFNO with spontaneous ventilation. Seventy-five percent of the patients had respiratory symptoms. Twelve patients (42.9%) were planned for the treatment of subglottic or tracheal stenosis and 5 patients were managed for vocal cord cancer (18.5%). Out of 32 surgeries, 4 cases of saturation < 92% occurred, 3 of them during the decrease of the fraction of inspired oxygen to 30% for the use of the laser. In 3 cases, the patients were intubated to correct the hypoxemia.

Conclusion

Spontaneous respiration using intravenous anesthesia and high-flow nasal oxygen is a modern technique that increases patient safety while allowing the surgeon to work without interruption or imputation of the operative field during SML. This approach is particularly promising for the management of airways compromised by tumors or laryngotracheal stenosis.

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.

Spontaneous Breathing for Panendoscopy? Retrospective Cohort and Results of a French Practice Survey

Objective

Avoiding tracheal intubation by using general anesthesia with spontaneous breathing (GASB) is attractive for upper airway panendoscopy. The aim of this study was to estimate the incidence of adverse events during panendoscopy under GASB and to assess the practices of French anesthesiologists.

Study Design

Two-phase study: monocentric retrospective study and national survey.

Setting

University hospital center.

Methods

Patients who underwent a panendoscopy under GASB at the University Hospital of Angers between January 1 and December 31, 2014, were reviewed. Failure of GASB was defined as an episode of hypoxemia (SpO₂ ≤88%) or the need for face mask ventilation with or without tracheal intubation. Then, we sent an electronic survey to all members of the French Society of Anaesthesia and Intensive Care.

Results

Among the 95 included patients, 22 (23%) experienced a failure of GASB: 3 tolerated hypoxemia, 15 had face mask ventilation episodes, and 4 were intubated. Three factors were associated with failure: obesity (odds ratio, 11.94; 95% CI, 3.20-44.64), history of difficult intubation defined as a Cormack score ≥3 (odds ratio, 6.20; 95% CI, 1.51-25.41), and laryngeal tumor (odds ratio, 2.81; 95% CI, 1.04-7.56). Among the 3930 members of the French Society of Anaesthesia and Intensive Care in 2018, 662 (16.8%) responded to the survey. The 2 preferred techniques to perform panendoscopy were intubation (62%) and intravenous sedation with spontaneous breathing (37%).

Conclusion

Although general anesthesia with orotracheal intubation remains the preferred technique for panendoscopy in France, GASB is an attractive alternative with a low failure rate. Risk factors for failure are obesity, history of difficult intubation, and laryngeal tumor.

The Effect of High-Flow Nasal Oxygen on Carbon Dioxide Accumulation in Apneic or Spontaneously Breathing Adults During Airway Surgery: A Randomized-Controlled Trial

BACKGROUND

High-flow nasal oxygen (HFNO) is an emerging technology that has generated interest in tubeless anesthesia for airway surgery. HFNO has been shown to maintain oxygenation and CO2 clearance in spontaneously breathing patients and is an effective approach to apneic oxygenation. Although it has been suggested that HFNO can enhance CO2 clearance during apnea, this has not been established. The true extent of CO2 accumulation and resulting acidosis using HFNO during prolonged tubeless anesthesia remains undefined.

METHODS

In a single-center trial, we randomly assigned 20 adults undergoing microlaryngoscopy to apnea or spontaneous ventilation (SV) using HFNO during 30 minutes of tubeless anesthesia. Serial arterial blood gas analysis was performed during preoxygenation and general anesthesia. The primary outcome was the partial pressure of CO2 (Paco2) after 30 minutes of general anesthesia, with each group compared using a Student t test.

RESULTS

Nineteen patients completed the study protocol (9 in the SV group and 10 in the apnea group). The mean (standard deviation [SD]) Paco2 was 89.0 mm Hg (16.5 mm Hg) in the apnea group and 55.2 mm Hg (7.2 mm Hg) in the SV group (difference in means, 33.8; 95% confidence interval [CI], 20.6-47.0) after 30 minutes of general anesthesia (P < .001). The average rate of Paco2 rise during 30 minutes of general anesthesia was 1.8 mm Hg/min (SD = 0.5 mm Hg/min) in the apnea group and 0.8 mm Hg/min (SD = 0.3 mm Hg/min) in the SV group. The mean (SD) pH was 7.11 (0.04) in the apnea group and 7.29 (0.06) in the SV group (P < .001) at 30 minutes. Five (55%) of the apneic patients had a pH <7.10, of which the lowest measurement was 7.057. No significant difference in partial pressure of arterial O2 (Pao2) was observed after 30 minutes of general anesthesia.

CONCLUSIONS

CO2 accumulation during apnea was more than double that of SV after 30 minutes of tubeless anesthesia using HFNO. The use of robust measurement confirms that apnea with HFNO is limited by CO2 accumulation and the concomitant severe respiratory acidosis, in contrast to SV. This extends previous knowledge and has implications for the safe application of HFNO during prolonged procedures.

Anesthetic Management for Awake Tubeless Suspension Microlaryngoscopy

OBJECTIVES/HYPOTHESIS

Patients' eligibility for bilateral selective laryngeal reinnervation surgery is evaluated by suspension microlaryngoscopy (SML) examination with laryngeal electromyography (LEMG). Maintaining spontaneous ventilation, with remifentanil sedation/analgesia without endotracheal tube, to allow the patient to phonate with the surgeon during awake, LEMG is a major challenge for the anesthesiologist and the otorhinololaryngologist. The objective of this study was to evaluate the safety and efficacy of a novel anesthesia protocol to manage airway access during awake tubeless SML.

STUDY DESIGN

Retrospective study.

METHODS

Anesthesia records of patients undergoing awake SML with LEMG were retrospectively analyzed. Procedures were performed with remifentanil sedation/analgesia with targeted controlled infusion (TCI) in combination with local anesthesia. The main outcome was the failure rate of the anesthesia protocol during the procedure. Secondary outcomes were as follows: rate of apnea requiring ventilation, airway bleeding, regurgitation, hemodynamic data as well as vasopressor use, complications, and surgeon satisfaction with the procedure.

RESULTS

Data were obtained for 39 patients between November 2017 and September 2019, the mean age was 52 years and 29 (74%) were female. All procedures were completed without complications (0% [0-9]). Three patients (8% [1.6-20.8]) had an intraoperative episode of hypoxemia requiring mask reventilation. There was no airway bleeding, no regurgitation, and no hypotensive episode. Three patients (8% [1.6-20.8]) had noninvasive ventilation for respiratory distress after the end of the procedure.

CONCLUSIONS

Our results show that awake tubeless SML allowing phonation during LEMG can be realized under sedation and local anesthesia. However, further data are needed concerning the intraoperative and postoperative safety of the procedure.

LEVEL OF EVIDENCE

4. Laryngoscope, 2021.

SponTaneous Respiration using IntraVEnous anaesthesia and Hi-flow nasal oxygen (STRIVE Hi) maintains oxygenation and airway patency during management of the obstructed airway: an observational study

Background. High-flow nasal oxygen (HFNO) has been shown to benefit oxygenation, ventilation and upper airway patency in a range of clinical scenarios, however its use in spontaneously breathing patients during general anaesthesia has not been described. Spontaneous respiration using i.v. anaesthesia is the primary technique used at our institution for tubeless airway surgery. We hypothesized that the addition of HFNO would increase our margin of safety, particularly during management of an obstructed airway.

Methods. A retrospective observational study was conducted using a SponTaneous Respiration using IntraVEnous anaesthesia and High-flow nasal oxygen (STRIVE Hi) technique to manage 30 adult patients undergoing elective laryngotracheal surgery.

Results. Twenty-six patients (87%) presented with significant airway and/or respiratory compromise (16 were stridulous, 10 were dyspnoeic). No episodes of apnoea or complete airway obstruction occurred during the induction of anaesthesia using STRIVE Hi. The median [IQR (range)] lowest oxygen saturation during the induction period was 100 [99–100 (97–100)] %. The median [IQR (range)] overall duration of spontaneous ventilation was 44 [40–49.5 (18–100)] min. The median [IQR (range)] end-tidal carbon dioxide (ETCO₂) level at the end of the spontaneous ventilation period was 6.8 [6.4–7.1 (4.8–8.9)] kPa. The mean rate of increase in ETCO₂ was 0.03 kPa min⁻¹.

Conclusions. STRIVE Hi succeeded in preserving adequate oxygen saturation, end-tidal carbon dioxide and airway patency. We suggest that the upper and lower airway benefits attributed to HFNO, are ideally suited to a spontaneous respiration induction, increasing its margin of safety. STRIVE Hi is a modern alternative to the traditional inhalation induction.