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

High-flow nasal oxygen for children's airway surgery to reduce hypoxaemic events: a randomised controlled trial

BACKGROUND

Tubeless upper airway surgery in children is a complex procedure in which surgeons and anaesthetists share the same operating field. These procedures are often interrupted for rescue oxygen therapy. The efficacy of nasal high-flow oxygen to decrease the frequency of rescue interruptions in children undergoing upper airway surgery is unknown.

METHODS

In this multicentre randomised trial conducted in five tertiary hospitals in Australia, children aged 0-16 years who required tubeless upper airway surgery were randomised (1:1) by a web-based randomisation tool to either nasal high-flow oxygen delivery or standard oxygen therapy (oxygen flows of up to 6 L/min). Randomisation was stratified by site and age (<1 year, 1-4 years, and 5-16 years). Subsequent tubeless upper airway surgery procedures in the same child could be included if there were more than 2 weeks between the procedures, and repeat surgical procedures meeting this condition were considered to be independent events. The oxygen therapy could not be masked, but the investigators remained blinded until outcome data were locked. The primary outcome was successful anaesthesia without interruption of the surgical procedure for rescue oxygenation. A rescue oxygenation event was defined as an interruption of the surgical procedure to deliver positive pressure ventilation using either bag mask technique, insertion of an endotracheal tube, or laryngeal mask to improve oxygenation. There were ten secondary outcomes, including the proportion of procedures with a hypoxaemic event (SpO2 <90%). Analyses were done on an intention-to-treat (ITT) basis. Safety was assessed in all enrolled participants. This trial is registered in the Australian New Zealand Clinical Trials Registry, ACTRN12618000949280, and is completed.

FINDINGS

From Sept 4, 2018, to April 12, 2021, 581 procedures in 487 children were randomly assigned to high-flow oxygen (297 procedures) or standard care (284 procedures); after exclusions, 528 procedures (267 assigned to high-flow oxygen and 261 assigned to standard care) in 483 children (293 male and 190 female) were included in the ITT analysis. The primary outcome of successful anaesthesia without interruption for tubeless airway surgery was achieved in 236 (88%) of 267 procedures on high-flow oxygen and in 229 (88%) of 261 procedures on standard care (adjusted risk ratio [RR] 1·02, 95% CI 0·96-1·08, p=0·82). There were 51 (19%) procedures with a hypoxaemic event in the high-flow oxygen group and 57 (22%) in the standard care group (RR 0·86, 95% CI 0·58-1·24). Of the other prespecified secondary outcomes, none showed a significant difference between groups. Adverse events of epistaxis, laryngospasm, bronchospasm, hypoxaemia, bradycardia, cardiac arrest, hypotension, or death were similar in both study groups.

INTERPRETATION

Nasal high-flow oxygen during tubeless upper airway surgery did not reduce the proportion of interruptions of the procedures for rescue oxygenation compared with standard care. There were no differences in adverse events between the intervention groups. These results suggest that both approaches, nasal high-flow or standard oxygen, are suitable alternatives to maintain oxygenation in children undergoing upper airway surgery.

FUNDING

Thrasher Research Fund, the Australian and New Zealand College of Anaesthetists, the Society for Paediatric Anaesthesia in New Zealand and Australia.

Trans-nasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) and its Utility in Otolaryngology, Head and Neck Surgery: A Literature Review

High-flow nasal oxygen (HFNO) therapy is extensively used in critical care units for spontaneously breathing patients. Trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) is a method of apnoeic oxygenation with continuous nasal delivery of warmed, humidified oxygen at high-flow rates up to 70L/min. THRIVE extends the apnoeic window before desaturation occurs so that tubeless anaesthesia is possible. The advent of THRIVE has had a monumental impact on anaesthetic practice, with a diverse range of clinical applications and it has been incorporated into difficult airway guidelines. THRIVE has many applications in otolaryngology and head and neck surgery. It is used as a pre-oxygenation tool during induction in both anticipated and unanticipated difficult airway scenarios and as a method of oxygenation for tubeless anaesthesia in elective laryngotracheal and hypopharyngeal surgeries and during emergence from anaesthesia. In this scoping review of the literature, we aim to provide an overview on the utility of THRIVE in otolaryngology, including the underlying physiologic principles, current indications and limitations, and its feasibility and safety in different surgical contexts and specific population groups.

Optimizing nonintubated laryngeal microsurgery: The effectiveness and safety of superior laryngeal nerve block with high-flow nasal oxygen-A prospective cohort study

BACKGROUND

Laryngeal microsurgery (LMS) typically requires intubated general anesthesia (ITGA). Although nonintubated general anesthesia (NIGA) with high-flow nasal oxygen (HFNO) can be applied with LMS, a muscle relaxant is required, which can cause apnea and hypercapnia. This study evaluated the effectiveness of a superior laryngeal nerve block (SLNB) in improving safety during LMS.

METHODS

This prospective cohort study enrolled a cumulative total of 61 adult patients received LMS under intravenous general anesthesia and allocated to three groups: ITGA group (n = 18), which patients performed intubation; neuromuscular blocking (NMB) group (n = 21), which patients administrated muscle relaxant without intubation and superior laryngeal nerve block (NB) group (n = 22), which patients performed SLNB without intubation or muscle relaxant.

RESULTS

The average (SD) values of PaCO 2 after surgery in ITGA, NMB, and NB group were 50.8 (7.5), 97.5 (24.9), and 54.8 (8.8) mmHg, respectively. The mean postoperative pH values were 7.33 (0.04), 7.14 (0.07), and 7.33 (0.04), respectively. The results were all p < 0.001, and the average pH value of the NMB group was lower than that of the ITGA and NB groups. During the LMS, the mean heart rate (HR) (93.9 [18.1] bpm) and noninvasive blood pressure systolic (NBPs) (143.5 [28.2] mmHg) in the NMB group were higher than those in the ITGA group (HR = 77.4 [13.5] bpm and NBPs = 132.7 [20.8] mmHg) and NB group (HR = 82.3 [17.4] bpm and NBPs = 120.9 [25.0] mmHg). The results of p value by HR and NBPs are p < 0.001. The PaCO 2 and pH values are similar between ITGA group and NB group.

CONCLUSION

Our approach of using HFNO with SLNB was successful for performing nonintubated LMS, enabling the patients to maintain spontaneous breathing and effectively eliminate CO 2 . This approach reduces the risks of hypercapnia and acidosis even when the duration of LMS exceeds 30 minutes.

Airway management with Hi-flow nasal cannula oxygen in children with severe laryngeal obstruction

BACKGROUND

The aim of this study was to report our initial experience in airway management in young children with severe laryngeal obstruction. Hi-flow nasal cannula oxygen (HFNO) with spontaneous respiration was used as a new airway management strategy in young children undergoing suspension laryngoscopic surgery.

METHODS

Children aged between 1 day and 24 months scheduled for suspension laryngoscopy were retrospectively studied. The data collected included the patients' age, gender, American Society of Anaesthesiologists physical status classification, comorbidities, preoperative physiological status, methods of induction and maintenance of anesthesia, course of the disease and surgical options, lowest oxygen saturation recorded, transcutaneous CO2, duration of operation, and patients' need for rescue methods.

RESULTS

A total of 38 patients successfully underwent suspension laryngoscopy under HFNO with spontaneous respiration. 19 patients were less than 1 year old (7 neonates), while the other half were less than or equal to 2 years old. The median [IQR (range)] lowest oxygen saturation recorded during the operation was 98 [93-99 (91-99)] %. The median [IQR (range)] duration of HFNO with spontaneous respiration was 65 [45-100 (30-200)] minutes. The median [IQR (range)] PCO2/PtcCO2 at the end of the spontaneous ventilation period was 54 [48-63 (39-70)] mmHg, which was the same as the preoperative PCO2 despite a long operation time.

CONCLUSIONS

HFNO with spontaneous respiration emerged as a new airway management strategy in young children with severe laryngeal obstruction that was beneficial in maintaining oxygenation and was superior to transnasal humidified rapid insufflation ventilatory exchange (THRIVE) in terms of the rising rate of PCO2 in these patients, thereby prolonging the safety time of the operation.

Addressing desaturation in a tracheal stenosis patient using the transnasal humidified rapid-insufflation ventilatory exchange technique during tracheostomy: A case report

RATIONALE

Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is used in tracheostomy but not in cases of airway obstruction. This case report explores the use of THRIVE for managing airway obstruction during tracheostomy in patients with subglottic and tracheal stenosis, thereby addressing the current knowledge gap and exploring its potential for airway management.

PATIENT CONCERNS

A 63-year-old female with subglottic and tracheal stenoses underwent tracheostomy. Multiple attempts to establish a patent airway were unsuccessful, and oxygen saturation dropped to 56%.

DIAGNOSIS

Endotracheal tube was directed toward the tracheal wall, causing airway obstruction.

INTERVENTIONS

THRIVE was administered to the patient. Subsequently, the tube position was adjusted to enhance ventilation.

OUTCOMES

The patient's oxygen saturation increased to 99%. The postoperative complications, including subcutaneous emphysema, pneumothorax, pneumomediastinum and pneumopericardium, resolved. The patient was discharged on postoperative day 9.

LESSONS

THRIVE could be considered a temporary measure to enhance oxygenation before initiating a definitive treatment strategy.

High-flow Nasal Cannula versus Conventional Ventilation in Laryngeal Surgery: A Systematic Review and Meta-analysis

High-flow nasal cannula (HFNC) is an emerging option for maintaining oxygenation in patients undergoing laryngeal surgery, as an alternative to traditional tracheal ventilation and jet ventilation (JV). However, the data on its safety and efficacy is sparse. This study aims to aggregate the current data and compares the use of HFNC with tracheal intubation and jet ventilation in adult patients undergoing laryngeal surgery. We searched PubMed, MEDLINE (Medical Literature Analysis and Retrieval System Online, or MEDLARS Online), Embase (Excerpta Medica Database), Google Scholar, Cochrane Library, and Web of Science. Both observational studies and prospective comparative studies were included. Risk of bias was appraised with the Cochrane Collaboration Risk of Bias in Non-Randomized Studies - of Interventions (ROBINS-I) or RoB2 tools and the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for case series. Data were extracted and tabulated as a systematic review. Summary statistics were performed. Meta-analyses and trial sequential analyses of the comparative studies were performed. Forty-three studies (14 HFNC, 22 JV, and seven comparative studies) with 8064 patients were included. In the meta-analysis of comparative studies, the duration of surgery was significantly reduced in the THRIVE (Transnasal Humidified Rapid-Insufflation Ventilatory Exchange) group, but the number of desaturations, need for rescue intervention, and peak end-tidal CO₂ were significantly increased compared to the conventional ventilation group. The evidence was of moderate certainty and there was no evidence of publication bias. In conclusion, HFNC may be as effective as tracheal intubation in oxygenation during laryngeal surgery in selected adult patients and reduces the duration of surgery but conventional ventilation with tracheal intubation may be safer. The safety of JV was comparable to HFNC.

Comparison of the application of high-flow nasal oxygen with two different oxygen concentrations in infant and child laryngotracheal surgery

Background

This study aimed to compare the use of the STRIVE Hi technique with 70 and 100% oxygen concentrations in children with 1st or 2nd degree laryngeal obstruction undergoing suspension laryngoscopic surgery.

Methods

Children aged 1 month to 6 years scheduled for suspension laryngoscopic surgery with spontaneous respiration were randomly divided into the 70% oxygen concentration group (HFNO70% group) and the 100% oxygen concentration group (HFNO100% group). The data recorded for all the patients included age and sex, comorbidities, preoperative physiological status, methods of induction and maintenance of anesthesia, course of the disease and surgical options, and duration of operation. The primary endpoint was the lowest oxygen saturations during the surgery. The secondary endpoints included the partial pressure of oxygen PaO2, the arterial pressure of carbon dioxide PaCO2, the peak transcutaneous carbon dioxide PtcCO2, and the incidence of desaturation (defined as SpO2 &lt; 90%) or hypercarbia (PtcCO2 &gt; 65 mmHg).

Results

A total of 80 children with 1st or 2nd degree laryngeal obstruction were included in the analysis. The median [IQR (range)] duration of spontaneous ventilation using STRIVE Hi was 52.5 [40–60 (30–170)]min and 62.5 [45–81 (20–200)]min in the HFNO 70% and HFNO 100% groups, respectively (p = 0.99); the lowest oxygen saturation recorded during the operation was 97.8 ± 2.1% and 96.8 ± 2.5%, respectively (p = 0.053); the mean PaO2 at the end of surgery was 184.6 ± 56.3 mmHg and 315.2 ± 101.3 mmHg, respectively (p &lt; 0.001); and the peak transcutaneous CO2 was 58.0 ± 13.0 mmHg and 60.4 ± 10.9 mmHg, respectively (p = 0.373), despite a long operation time.

Conclusion

STRIVE Hi had a positive effect on children undergoing tubeless laryngeal surgery with spontaneous ventilation, and for children with 1st or 2nd degree laryngeal obstruction, there was no significant difference in maintaining the intraoperative oxygenation between the 70 and 100% oxygen concentration groups. The 100% oxygen concentration group showed significant hyperoxia, which has been proven to be associated with multiple organ damage. Using a relatively lower oxygen concentration of 70% can effectively reduce the hazards associated with hyperoxia compared to 100% oxygen concentration.

Clinical trial registration

[www.chictr.org.cn], identifier [CHICTR2200064500].

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.

Microlaryngeal Laser Surgery Using High-flow Nasal Ventilation at Two Oxygen Concentration Deliveries

OBJECTIVES

Ventilation using 100% oxygenation creates a risk of fire during laser microlaryngeal surgery (MLS). The purpose of this study is to describe the technique of transnasal high-flow ventilation using laser safe (30%) oxygen conditions, measure the intraoperative real-time laryngeal oxygen concentration, and examine patient saturation status using this technique.

METHODS

Prospective IRB approved study of patients undergoing tubeless laser MLS using high-flow nasal oxygenation. Delivered oxygen concentration was reduced from 100% to 30% before lasering using an oxygen-air blender then increased to 100% post-laser procedure. Outcome measures included time for laryngeal oxygen concentration to equalize to laser safe levels; time to, methods of and duration of rescue ventilation; and desaturation rates and apnoeic times at both 100% and 30% oxygen deliveries.

RESULTS

Fifty patients were recruited (mean age = 47.4 years). Mean laryngeal oxygen concentration (%) at 100% and 30% deliveries was 98.46 and 31.45, respectively. Mean (SD) of laryngeal oxygen concentration equalization time to 30% (seconds) was 9.4 (3.69). At 30% oxygen delivery desaturation rate was faster and apneic time shorter compared with 100%. Eighteen patients required rescue (jet) ventilation and they had a faster apneic desaturation rate (%/minute) than patients not requiring rescue. Mean (SD) apneic time (minutes) at 30% delivery was 4.56 (2.25) and 4.41 (2.18) in rescue versus non-rescue groups respectively. BMI was the only significant predictor of desaturation rate at 30% oxygen delivery.

CONCLUSION

It is possible to achieve a safe time window for use of laser during MLS using transnasal humidified high-flow ventilation by delivering 30% oxygen concentration.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:634-639, 2023.

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.

[The perioperative role of high-flow cannula oxygen (HFNO)]

High-flow nasal cannula oxygen (HFNO) is commonly used during the perioperative period. Its numerous physiological benefits, satisfactory tolerance and ease of use have led to its widespread application in intensive care and post-anesthesia care units. HFNO is also used in the operating theater in multiple indications: as oxygen supplementation (associated with pressurization) prior to orotracheal intubation; in digestive and bronchial endoscopies, especially in patients at risk of hypoxemia; and in intraoperative surgery requiring spontaneous ventilation (ENT, thoracic surgery…). During the postoperative period, HFNO can be used in a curative strategy for respiratory failure or in a prophylactic strategy to prevent reintubation. In a curative approach, HFNO seems of interest following cardiac or thoracic surgery but has not been evaluated in respiratory failure subsequent to abdominal surgery, in which case noninvasive ventilation remains the gold standard. The risk of respiratory complications depends on type of surgery and on patient comorbidities. As prophylaxis, HFNO is currently preferred to conventional oxygen therapy after cardiac or thoracic surgery, especially in patients at high risk of respiratory complications. For the clinician, it is important to acknowledge the limits of HFNO and to closely monitor patients receiving HFNO, the objective being to avoid delays in intubation that could lead to increased mortality.

High-flow nasal oxygen for suspension laryngoscopy: a multicenter open-label study

In this study, we aimed to assess the efficacy of high-flow nasal oxygen (HFNO) to maintain blood peripheral oxygen saturation (SpO2) in patients undergoing suspension laryngoscopy under general anesthesia. Adult patients were included in this bicenter study. After face-mask oxygenation, HFNO at a flow rate of 70 L min^-1 and fraction of inspired oxygen 100% was initiated at loss of consciousness. At the end of HFNO, blood gas analysis was performed. Of the 29 included patients, five (17.2%; 95% confidence interval [CI]: 7.6-34.5) presented SpO2 <95% during the first 15 minutes of the procedure and eight patients (27.6%; 95% CI: 14.7-45.7) presented SpO2 <95% throughout the procedure. Six patients (20.7%; 95% CI: 9.8-38.4) required rescue jet ventilation. Median apnea time before SpO2 <95% was 13.5 (interquartile range [IQR]: 10-17.7) minutes. Arterial carbon dioxide tension at the end of the procedure or at the time of study discontinuation was 9.73 (IQR: 8.8-10.9) kPa and was higher than 8 kPa in 88.9% (95% CI: 71.9-96.1) of patients. HFNO was associated with a relatively high incidence of suboptimal oxygen saturation and hypercapnia during suspension laryngoscopy under general anesthesia and may not be considered the reference technique.

Efficacy of high-flow nasal oxygenation compared with laryngeal mask airway in children undergoing ambulatory oral surgery under deep sedation: A randomized controlled non-inferiority trial

BACKGROUND

High-flow nasal oxygenation (HFNO) has been suggested as an alternative oxygenation method during procedural sedation. This randomized, non-inferiority trial evaluated the safety and efficacy of HFNO compared with laryngeal mask airway (LMA) in pediatric ambulatory oral surgery under deep sedation.

METHODS

In total, 120 children aged 2-7 years (weight: 10-30 kg) were equally assigned into two groups, namely, HFNO with propofol total intravenous anesthesia infusion (HFNO-IV) or LMA with propofol total intravenous anesthesia infusion (LMA-IV). The primary objective was to monitor carbon dioxide (CO2) accumulation during perioperative surgery. Secondary objectives included monitoring transcutaneous oxygen saturation, grade exposure to the surgical field, perioperative adverse events, or other events. The predefined non-inferiority margin was 7 mmHg. During the COVID-19 pandemic, a novel WeChat applet was implemented to gather follow-up data after discharge.

RESULTS

Non-inferiority could be declared for HFNO relative to LMA (mean difference in transcutaneous CO2 (TcCO2) = -1.4 mmHg, 95% CI: -2.9, 0.1 mmHg; P > 0.05). The pre-surgical TcCO2 of the HFNO-IV group (45.4 ± 4.5 mmHg) was similar to that of the LMA-IV group (44.0 ± 3.5 mmHg), within the clinically acceptable normal range. All the children maintained SpO2 levels of >97%. The surgical field exposure score of the HFNO group was significantly better than that of the LMA group. There was no significant difference between the two groups regarding risk or adverse events.

CONCLUSION

HFNO was not inferior to LMA for maintaining oxygenation and ventilation in patients undergoing pediatric ambulatory oral surgery under deep sedation under strict isolation from the oral cavity to the upper airway.

Use of high-flow nasal oxygen in spontaneously breathing pediatric patients undergoing tubeless airway surgery: A prospective observational study

The use of high-flow nasal oxygen is gaining popularity in apneic and spontaneously breathing adult patients during anesthesia. This prospective observational study evaluated the effect of high-flow nasal oxygen in maintaining adequate oxygenation and ventilation in spontaneously breathing pediatric patients with dynamic airway obstruction, undergoing tubeless airway surgery. Oxygenation was provided via an age-appropriate, high-flow nasal cannula at a flow rate of 2 L kg-1 min-1. Propofol and remifentanil were used to maintain anesthesia while preserving spontaneous respiration. We sought to determine the incidence and risk factors of rescue ventilation. Rescue ventilation with a face mask was performed when the pulse oximetry oxygen saturation was <90% or transcutaneous carbon dioxide was >80 mm Hg. In total, 27 patients were included in the final analysis. Median (interquartile range) of pulse oximetry and transcutaneous carbon dioxide were 100% (99%-100%) and 58.4 mm Hg (51.4-70.3 mm Hg), respectively. Altogether, 9 (33.3%) patients needed rescue ventilation during anesthesia. Of these, 7 patients (25.9%) developed oxygen desaturation (<90%) and 2 patients (7.4%) developed hypercarbia. Patients who required rescue ventilation were significantly younger (8.2 vs 28.8 months, P = .02) and required a longer anesthesia time (55.7 vs 41.0 minutes, P = .04) than those who did not. In conclusion, High-flow nasal oxygen is an alternative technique to maintain oxygenation in children undergoing airway surgeries. However, younger age and longer anesthesia time are significant risk factors leading to the requirement of rescue ventilation in these patients. Further studies with large sample size are required for clinical application of these techniques.

Updated guideline on equipment to manage difficult airways: Australian and New Zealand College of Anaesthetists

The Australian and New Zealand College of Anaesthetists (ANZCA) recently reviewed and updated the guideline on equipment to manage a difficult airway. An ANZCA-established document development group, which included representatives from the Australasian College for Emergency Medicine and the College of Intensive Care Medicine of Australia and New Zealand, performed the review, which is based on expert consensus, an extensive literature review, and bi-nationwide consultation. The guideline (PG56(A) 2021, https://www.anzca.edu.au/getattachment/02fe1a4c-14f0-4ad1-8337-c281d26bfa17/PS56-Guideline-on-equipment-to-manage-difficult-airways) is accompanied by a detailed background paper (PG56(A)BP 2021, https://www.anzca.edu.au/getattachment/9ef4cd97-2f02-47fe-a63a-9f74fa7c68ac/PG56(A)BP-Guideline-on-equipment-to-manage-difficult-airways-Background-Paper), from which the current recommendations are reproduced on behalf of, and with the permission of, ANZCA. The updated 2021 guideline replaces the 2012 version and aims to provide an updated, objective, informed, transparent, and evidence-based review of equipment to manage difficult airways.

The effect of transnasal humidified rapid-insufflation ventilator exchange (THRIVE) versus nasal prongs on safe apnoea time in paralysed obese patients: a randomised controlled trial

BACKGROUND

Evidence is lacking regarding the efficacy of Optiflow transnasal humidified rapid-insufflation ventilator exchange (THRIVE™) in obese patients. We compared the impact of this technique at 70 L min^-1 with 4 L min^-1 oxygen via nasal prongs on safe apnoea times of paralysed obese patients.

METHODS

We randomised adults with a BMI >35 kg m^-2 undergoing elective bariatric surgery. While apnoeic and paralysed, Group T received 70 L min^-1 oxygen via Optiflow THRIVE™. Group N received nasal prong oxygen at 4 L min^-1. The primary outcome was time to SpO₂ ≤95% while apnoeic, with a 360 s cut-off. This was analysed by applying a time-to-event analysis.

RESULTS

Forty-two patients were included. The median (inter-quartile range) BMI was 44.8 kg m^-2 (40.0-50.0) in Group T and 42.0 kg m^-2 (39.3-45.1) in Group N. Median (inter-quartile range) time to SpO₂ ≤95% in Group T was 356 (165 to ≥360) s and in Group N, 210 (160-270) s. Using a survival analysis framework, median time-to-event in Group T was 356 s (95% confidence interval 165 s-upper limit not defined) and 210 s (95% confidence interval 160-242 s) (P=0.049) in Group N.

CONCLUSIONS

Compared with oxygen delivered via nasal prongs at 4 L min^-1, oxygen delivery via Optiflow THRIVE™ at a flow rate of 70 L min^-1 can prolong safe apnoea time, however, the results are statistically inconclusive. Optiflow THRIVE™ did decrease the rate of reduction in Pa_o2 during apnoea.

CLINICAL TRIAL REGISTRATION

ANZCTR 12618000445279.

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.

2021 Update on airway management from the Anaesthesia Continuing Education Airway Management Special Interest Group

Airway Management is the key for anaesthetists dealing with patients undergoing diagnostic procedures and surgical interventions. The present coronavirus pandemic underpins even more how important safe airway management is. It also highlights the need to apply stringent precautions to avoid infection and ongoing transmission to patients, anaesthetists and other healthcare workers (HCWs). In light of this extraordinary global situation the aim of this article is to update the reader on the varied aspects of the ever-changing tasks anaesthetists are involved in and highlight the equipment, devices and techniques that have evolved in response to changing technology and unique patient and surgical requirements.

Tracheal Dilatation of an Idiopathic Subglottic Stenosis in a Near-Term Parturient at 36 Weeks of Gestation Using SponTaneous Respiration Using Intravenous Anesthesia and Hi-Flow Nasal Oxygen: A Case Report

Hi-flow nasal oxygen (HFNO) has revolutionized tubeless field anesthesia for airway surgery without the complications of jet ventilation. However, its use in third trimester parturients undergoing open airway surgery has been limited to an apneic technique (Transnasal Humidified Rapid-Insufflation Ventilatory Exchange [THRIVE]) in current publications. We used SponTaneous Respiration using IntraVEnous anesthesia and Hi-flow nasal oxygen (STRIVE Hi) in the management of tracheal dilatation in a near-term parturient at 36 weeks of gestation. Transferring this established protocol for spontaneous ventilation in the obstructed airway onto near-term parturients may mitigate the risks of apnea with hypercapnia, subsequent acidosis, and potential fetal harm.

General anaesthesia in end-of-life care: extending the indications for anaesthesia beyond surgery

In this article, we describe an extension of general anaesthesia – beyond facilitating surgery – to the relief of suffering during dying. Some refractory symptoms at the end of life (pain, delirium, distress, dyspnoea) might be managed by analgesia, but in high doses, adverse effects (e.g. respiratory depression) can hasten death. Sedation may be needed for agitation or distress and can be administered as continuous deep sedation (also referred to as terminal or palliative sedation) generally using benzodiazepines. However, for some patients these interventions are not enough, and others may express a clear desire to be completely unconscious as they die. We summarise the historical background of an established practice that we refer to as ‘general anaesthesia in end‐of‐life care’. We discuss its contexts and some ethical and legal issues that it raises, arguing that these are largely similar issues to those already raised by continuous deep sedation. To be a valid option, general anaesthesia in end‐of‐life care will require a clear multidisciplinary framework and consensus practice guidelines. We see these as an impending development for which the specialty should prepare. General anaesthesia in end‐of‐life care raises an important debate about the possible role of anaesthesia in the relief of suffering beyond the context of surgical/diagnostic interventions.

Management of critical tracheal stenosis with a straw sized tube (Tritube): Case report

Imminent upper airway obstruction due to life-threatening tracheal stenosis of any cause is a challenging situation. We present a challenging case of total thyroidectomy for a malignant, invasive, and highly vascularized thyroid carcinoma that has invaded the surrounding tissues, including the sternum and mediastinum, resulting in compression of the trachea with indentation. The patient presented with a significant symptomatic tracheal stenosis, the narrowest area of that was 4 mm. Airway management in such cases presents a particular challenge to the anesthesiologists, especially considering that the option of tracheostomy is very difficult most of the time due to the highly swollen thyroid and distorted anatomy. A meticulous history of the patient's illness had been taken, and a comprehensive preoperative evaluation was conducted, including construction of a 3D model airway, virtual endoscopy, and transnasal tracheoscopy. On the day of the surgery, the airway was managed through spontaneous respiration using intravenous anesthesia and the high-flow nasal oxygen (STRIVE-Hi) technique. It was then secured with intubation using a straw endotracheal tube (Tritube®) with an internal diameter (ID) of 2.4 mm and an outer diameter of 4.4 mm with the help of a fiberscope and D-MAC blade of a video laryngoscope. At the end of the procedure, the airway was checked with a fiber optic scope, which showed an improvement in the narrowed area. This enabled us to replace the Tritube with an adult cuffed ETT of size 6.5 mm ID, and the patient was transferred intubated to the surgical ICU. Two days later, the patient's tracheal diameter was evaluated with the help of a fiberoptic scope and extubated successfully in the operating theater.

Feasibility of Surgical Treatment for Laryngomalacia using Spontaneous Respiration Technique

Objectives.

In this study, we review our institutional experience with pediatric laryngomalacia (LM) and report our experiences of patients undergoing supraglottoplasty using the spontaneous respiration using intravenous anesthesia and high-flow nasal oxygen (STRIVE Hi) technique.

Methods.

The medical records of 29 children with LM who visited Seoul National University Hospital between January 2017 and March 2019 were retrospectively reviewed. Surgical management was performed using the STRIVE Hi technique. Intraoperative findings and postoperative surgical outcomes, including complications and changes in symptoms and weight, were analyzed.

Results.

Of the total study population of 29 subjects, 20 (68.9%) were female. The patients were divided according to the Onley classification as follows: type I (n=13, 44.8%), II (n=10, 34.5%), and III (n=6, 20.7%). Twenty-five patients (86.2%) had comorbidities. Seventeen patients (58.6%) underwent microlaryngobronchoscopy under STRIVE Hi anesthesia. Four patients with several desaturation events required rescue oxygenation by intermittent intubation and mask bagging during the STRIVE Hi technique. However, the procedure was completed in all patients without any severe adverse effects. Overall, 15 children (51.7%) underwent supraglottoplasty, of whom 14 (93.3%) showed symptom improvement, and their postoperative weight percentile significantly increased (P=0.026). One patient required tracheostomy immediately after supraglottoplasty due to associated neurological disease.

Conclusion.

The STRIVE Hi technique is feasible for supraglottoplasty in LM patients, while type III LM patients with micrognathia or glossoptosis may have a higher risk of requiring rescue oxygenation during the STRIVE Hi technique.

A novel application of Transnasal Humidified Rapid Insufflation Ventilatory Exchange via the oral route in morbidly obese patient during monitored anesthesia care - A case report

Background

Transnasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) is used to improve oxygenation, with the added benefit of a smaller increase in CO₂ if self-respiration is maintained with THRIVE. Despite these advantages, the use of THRIVE through a nasal cannula is limited in situations such as epistaxis or a basal skull fracture.

Case

We successful used THRIVE, through the oral route under general anesthesia with spontaneous breathing in a morbidly obese patient (weight, 148 kg; height, 183 cm; body mass index, 44.2 kg/m²) who received transnasal steroid injections due to subglottic stenosis.

Conclusions

THRIVE through the oral route may be an effective novel option, although further studies are needed.

Channeled fiberoptic for vocal cord polyp excision under spontaneous respiration using intravenous anesthesia and hi-flow nasal oxygen (STRIVE-Hi) technique: A case report and review of the literature

Microlaryngoscopy for benign vocal cord lesion excision is a procedure with good outcomes and relatively few complications that is performed worldwide. The anterior one-third of the vocal cords is a relatively common site to find benign polyps, and the excision of cases with adequate laryngeal exposure is relatively easy. However, they can sometimes present a challenge when laryngeal exposure is suboptimal, which leads to trouble in accessing the site. The factors that can lead to difficulties in laryngeal exposure are numerous, such as restricted mouth opening, limited neck extension, large tongue size, and others. The preoperative prediction of difficult laryngeal exposure (DLE) can be obtained by different scoring and grading systems. We have used the Laryngoscore in this case. However, management options for such cases remain limited. Here, we present a case that was managed using channeled cup forceps under fiberoptic endoscopy with the STRIVE-Hi technique used to administer anesthesia.

The Effectiveness of High-Flow Nasal Oxygen During the Intraoperative Period: A Systematic Review and Meta-analysis

BACKGROUND

High-flow nasal oxygen (HFNO) is increasingly being used in intensive care units for management of hypoxemia and respiratory failure. However, the effectiveness of HFNO for preventing hypoxemia in the intraoperative period is unclear. The purpose of this systematic review was to compare patient oxygenation and end-tidal CO2 (EtCO2), between HFNO and conventional oxygenation, during the intraoperative period in surgical patients.

METHODS

Standard databases were searched from inception to February 2020. Studies involving intraoperative use of HFNO with 1 of the 4 outcomes: (1) oxygen (O2) desaturation, (2) minimum O2 saturation, (3) safe apnea time, or (4) EtCO2 were included. Intraoperative period was divided into 2 phases: at induction with general anesthesia and during surgical procedure under sedation without tracheal intubation.

RESULTS

Eight randomized controlled trials (RCTs; 4 induction, 4 procedure, 2314 patients) were included for systematic review and meta-analyses. We found the risk of intraoperative O2 desaturation was lower in HFNO versus conventional oxygenation control group; at induction with an odds ratio (OR; 95% confidence interval [CI]) of 0.06 (0.01-0.59, P = .02), and during procedure, OR (95% CI) of 0.09 (0.05-0.18; P < .001). The minimum O2 saturation was higher in HFNO versus conventional oxygenation; at induction by a mean difference (MD) (95% CI) of 5.1% (3.3-6.9; P < .001), and during procedure, by a MD (95% CI) of 4.0% (1.8-6.2; P < .001). Safe apnea time at induction was longer in HFNO versus conventional oxygenation by a MD (95% CI) of 33.4 seconds (16.8-50.1; P < .001). EtCO2 at induction was not significantly different between HFNO and conventional oxygenation groups.

CONCLUSIONS

This systematic review and meta-analysis show that, in the intraoperative setting, HFNO compared to conventional oxygenation reduces the risk of O2 desaturation, increases minimum O2 saturation, and safe apnea time. HFNO should be considered for anesthesia induction and during surgical procedures under sedation without tracheal intubation in patients at higher risk of hypoxemia.

Nonintubated video-assisted thoracic surgery with high-flow oxygen therapy shorten hospital stay

BACKGROUND

Nonintubated video-assisted thoracic surgery (VATS) is widely used due to its acceptable postoperative outcomes. Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) has been successfully applied in cases of prolonged difficult intubation and intensive respiratory care in patients receiving VATS lobectomy. Thopaz Digital Chest Drainage System (THOPAZ) provides regulated negative pressure close to the patient's chest, optimizing drainage of the pleural and mediastinum. We explored the surgical outcomes of nonintubated VATS lung wedge resection and traditional wedge resection with a double-lumen endotracheal tube.

METHODS

Patients who received nonintubated VATS lung wedge resection (group A, n = 81) and traditional wedge resection with double-lumen endotracheal tube (group B, n = 79) during the period of November 2015 to April 2018 were enrolled in the study. Demographic data and operation outcomes were obtained and analyzed from review of patient medical charts.

RESULTS

Group B had significantly longer mean induction and operative times than group A. Similarly, group B suffered greater intraoperative blood loss, longer postoperative hospital stays, and increased chest tube retention times than group A. Group A had higher partial pressure of carbon dioxide levels in both the pre-one-lung and during one-lung ventilation periods than group B. Furthermore, group A showed lower serum pH levels during one-lung ventilation period. However; group A had significantly higher partial pressure of oxygen levels during one-lung ventilation than group B, although the differences in peripheral oxygen saturation were not statistically significant.

CONCLUSION

Our study demonstrated that nonintubated VATS using THRIVE and THOPAZ in lung wedge resection provides measurable benefits to patients.

Successful Use of High-Flow Nasal Cannula for Concurrent Vocal Cord Electromyography and Tubeless Microlaryngeal Surgery in a Spontaneously Breathing Adult Patient: A Case Report

Ventilation during microlaryngoscopy previously included jet ventilation, microlaryngeal endotracheal tubes, and extended apnea. Historically, apneic oxygenation provided a tubeless field but limited operative time. Increased utilization of high-flow nasal cannula in intensive care units and operating rooms has created new opportunities to expand tubeless microlaryngoscopy. Although few studies have described high-flow nasal cannula for microlaryngoscopy, there remains much to be explored. In this case report, we describe the unique setting of utilizing high-flow nasal cannula in a spontaneously breathing patient to create an optimal tubeless surgical field for both microlaryngoscopy and vocal cord electromyography.

Pediatric airway surgery under spontaneous respiration using high-flow nasal oxygen

OBJECTIVES

In pediatric airway surgery, SponTaneous Respiration using IntraVEnous anesthesia and Hi-flow nasal oxygen (STRIVE Hi) has not been well explored. Here, we report our experience of using STRIVE Hi in endoscopic evaluations and surgeries of the pediatric airway.

METHODS

This retrospective review was based on 45 airway procedures conducted under STRIVE Hi, performed by a single surgeon at a single institute from May 2017 to September 2018. After induction of anesthesia, continuous infusion with propofol and remifentanil was provided to ensure an adequate level of anesthesia and supply of humidified oxygen via a nasal cannula. Monitoring was conducted using a transcutaneous CO₂ sensor and a pulse oximeter, and the oxygen reserve and bispectral indexes were measured. No muscle relaxant was administered.

RESULTS

The median age of the patients was 16.0 months (range: 1-215 months) and the median weight was 10.2 kg (range: 2.4-38.5 kg). The median duration of spontaneous respiration was min 40 (range: 10-140 min). The airway procedures included diagnostic microlaryngoscopy, tracheocutaneous fistula excision, balloon dilation, supraglottoplasty, laryngeal cleft repair, injection laryngoplasty, papilloma excision, and subglottic cyst removal. During these procedures, STRIVE Hi facilitated evaluation of dynamic obstruction of the airway and the immediate outcome of surgical treatment and provided a good surgical view. Intubation and the termination of spontaneous respiration were required in only five patients.

CONCLUSIONS

STRIVE Hi is an effective and feasible anesthesia option in pediatric airway surgery. It provides unobstructed surgical access and is applicable to a wide range of procedures.

Comparison of a simplified nasal continuous positive airways pressure device with nasal cannula in obese patients undergoing colonoscopy during deep sedation: A randomised clinical trial

BACKGROUND

Continuous positive airways pressure (CPAP) with a CPAP machine and mask has been shown to be more effective at minimising hypoxaemia than other devices under deep sedation. However, the efficacy of a new and simple CPAP device for spontaneously breathing obese patients during colonoscopy is unknown.

OBJECTIVE

We hypothesised that oxygenation and ventilation in obese patients under deep sedation during colonoscopy using CPAP via a new nasal mask (SuperNO2VA) would be better than routine care with oxygen supplementation via a nasal cannula.

DESIGN

Randomised study.

SETTING

Single-centre, June 2017 to October 2017.

PATIENTS

A total of 174 patients were enrolled and randomly assigned to Mask group or Control group. Thirty-eight patients were excluded and data from 136 patients underwent final analysis.

INTERVENTION

Patients in the Mask group were provided with nasal CPAP (10 cmH2O) at an oxygen flow rate of 15 l min. In the Control group, patients were given oxygen via a nasal cannula at a flow rate of 5 l min.

MAIN OUTCOME MEASURES

The primary outcome was elapsed time from anaesthesia induction to the first airway intervention.

RESULTS

The elapsed time from anaesthesia induction to the first airway intervention was 19 ± 10 min in the Mask group (n=63) vs. 10 ± 12 min in the Control group (n=73, P < 0.001). In all, 87.5% (56/64) of patients achieved the target CPAP value. More patients in the Control group (63%) received airway intervention than in the Mask group (22%) (P < 0.001). Hypoxaemia (pulse oximeter oxygen saturation, SpO2 < 90%) occurred more frequently in the Control group (22%) than in the Mask group (5%) (P = 0.004). Minute ventilationPostinduction/minute ventilationBaseline and minute ventilationProcedure-end/minute ventilationBaseline was lower in the Control group than in the Mask group (P = 0.007 and 0.001, respectively).

CONCLUSION

Application of a nasal mask at a target CPAP of 10 cmH2O improves ventilation and decreases the frequency and severity of hypoxaemia.

TRIAL REGISTRATION

NCT03139448, registered at ClinicalTrials.gov.

Re-emergence of TIVA in COVID times

Total intravenous anaesthesia (TIVA) is a technique of general anaesthesia (GA) given via intravenous route exclusively. In perspective of COVID-19, TIVA is far more advantageous than inhalational anaesthesia. It avoids the deleterious effects of immunosuppression and lacks any respiratory irritation, thus providing an edge in the current situation. Many peripheral surgeries can be done with the patient breathing spontaneously without any airway device, thus avoiding airway instrumentation leading to droplet and aerosol generation. Intravenous agents can be utilized to provide sedation during regional anaesthesia (RA), which can easily be escalated to contain pain due to sparing of blocks or receding neuraxial anaesthesia. The present narrative review focuses on the merits of adopting TIVA technique during this pandemic so as to decrease the risk and morbidity arising from anaesthetizing COVID-19 patients.

Nasal high-flow oxygen in pediatric anesthesia and airway management

Nasal High-Flow (NHF) is weight-dependent in children, aimed to match peak inspiratory flow and thereby deliver an accurate FiO₂ with a splinting pressure of 4-6 cm H₂ O. During apnea in children, NHF oxygen can double the expected time to desaturation below 90% in well children but there is no ventilatory exchange; therefore, children do not "THRIVE". Total intravenous anesthesia competency to maintain spontaneous breathing is an important adjunct for successful NHF oxygenation technique during anesthesia. Jaw thrust to maintain a patent upper airway is paramount until surgical instrumentation occurs. There is no evidence to support safe use of NHF oxygen with LASER use due to increased risk of airway fire.

Comparison of preoxygenation with a high-flow nasal cannula and a simple mask before intubation during induction of general anesthesia in patients undergoing head and neck surgery: Study protocol clinical trial (SPIRIT Compliant)

BACKGROUND

To assess the arterial oxygen partial pressure (PaO2) at defined time points during preoxygenation and to compare high-flow heated humidified nasal oxygenation with standard preoxygenation using oxygen insufflation via a facemask for at least 5 minutes, before intubation during induction of general anesthesia.

METHODS

This randomized, single-blinded, prospective study will be conducted in patients undergoing head and neck surgery. After standard monitoring, the artery catheter at the radial artery or dorsalis pedis artery will be placed and arterial blood gas analysis (ABGA) for baseline values will be performed simultaneously. Each group will be subjected to 1 of 2 preoxygenation methods (high-flow nasal cannula or simple facemask) for 5 minutes, and ABGA will be performed twice. After confirming intubation, we will start mechanical ventilation and check the vital signs and perform the final ABGA.

DISCUSSION

This trial aims to examine the trajectory of PaO2 levels during the whole preoxygenation procedure and after intubation. We hypothesize that preoxygenation with the high-flow nasal cannula will be superior to that with the face mask.

STUDY REGISTRATION

This trial was registered with the Clinical Trial Registry (NCT03896906; ClinicalTrials.gov).

High Flow Nasal Cannula: A Game Changer in Airway Surgery

High flow nasal cannula (HFNC) delivers humidified oxygen at high flow. Its use during airway procedures has many advantages. The study was done to determine the duration of apnea time, safety and compatibility with laser, while using HFNC during airway procedures. A prospective study was done at a tertiary care hospital between March 2017 and August 2017 on 16 patients. HFNC was used during airway surgeries for various pathologies. There were 11 males and 5 females. The patient age ranged from 4 days to 28 years. HFNC provided an unobstructed view of the surgical field, laser could be used safely, there was an increase in the apnea window, and post-operative symptoms like throat irritation and cough were infrequent. Usage of HFNC provides an unobstructed view of the surgical field and reduces post-operative discomfort. It helps in difficult airway situations by optimizing oxygenation and increasing the apnea time.