Comparison of the effectiveness of high-flow nasal oxygen vs. standard facemask oxygenation for pre- and apneic oxygenation during anesthesia induction: a systematic review and meta-analysis

Perioxygenation During Advanced Airway Management

ABSTRACT

Advanced airway management is a skill that is used every day in patient care settings throughout the world. Albeit common, it is not benign. Advanced airway management may either be elective or urgent; in either case, it may result in significant patient morbiidity and mortality. The complications of difficult or failed endotracheal intubation can be severe and include death or permanent neurologic injury. Difficulty or failure with advanced airway management often coincides with the onset of hypoxia. The onset of hypoxia affects both the patient and the airway manager. While hypoxemia may result in dysrhythmias and ultimately cardiac arrest for the patient, it adds time pressure and stress to the airway manager, and thus may impact successful performance. In this review, we will discuss how to identify patients at risk for rapid desaturation during advanced airway management. Additionally, methods of peri-oxygenation throughout the performance of airway management will be discussed.

Airway management in patients with suspected or confirmed cervical spine injury: Guidelines from the Difficult Airway Society (DAS), Association of Anaesthetists (AoA), British Society of Orthopaedic Anaesthetists (BSOA), Intensive Care Society (ICS), Neuro Anaesthesia and Critical Care Society (NACCS), Faculty of Prehospital Care and Royal College of Emergency Medicine (RCEM)

BACKGROUND

There are concerns that airway management in patients with suspected or confirmed cervical spine injury may exacerbate an existing neurological deficit, cause a new spinal cord injury or be hazardous due to precautions to avoid neurological injury. However, there are no evidence-based guidelines for practicing clinicians to support safe and effective airway management in this setting.

METHODS

An expert multidisciplinary, multi-society working party conducted a systematic review of contemporary literature (January 2012-June 2022), followed by a three-round Delphi process to produce guidelines to improve airway management for patients with suspected or confirmed cervical spine injury.

RESULTS

We included 67 articles in the systematic review, and successfully agreed 23 recommendations. Evidence supporting recommendations was generally modest, and only one moderate and two strong recommendations were made. Overall, recommendations highlight key principles and techniques for pre-oxygenation and facemask ventilation; supraglottic airway device use; tracheal intubation; adjuncts during tracheal intubation; cricoid force and external laryngeal manipulation; emergency front-of-neck airway access; awake tracheal intubation; and cervical spine immobilisation. We also signpost to recommendations on pre-hospital care, military settings and principles in human factors.

CONCLUSIONS

It is hoped that the pragmatic approach to airway management made within these guidelines will improve the safety and efficacy of airway management in adult patients with suspected or confirmed cervical spine injury.

High-Flow Nasal Cannula versus Bag Valve Mask for Preoxygenation during Rapid Sequence Intubation in the Emergency Department: A Single-Center, Prospective, Randomized Controlled Trial

OBJECTIVE

Hypoxia is a frequently reported complication during the intubation procedure in the emergency department (ED) and may cause bad outcomes. Therefore, oxygenation plays an important role in emergency airway management. The efficacy of oxygenation with high-flow nasal cannula (HFNC) in the ED has been studied, though the evidence is limited. The study aim was to compare two methods of preoxygenation in patients undergoing rapid sequence intubation (RSI) in the ED: (1) HFNC and (2) bag-valve mask (BVM) oxygenation.

METHODS

This is a single-center, prospective, randomized controlled trial (RCT) in adult ED patients requiring RSI. Patients were randomized to receive preoxygenation with either HFNC or BVM. While HFNC therapy was continued during the intubation procedure, BVM oxygenation was interrupted for laryngoscopy. The primary outcome was the lowest peripheral oxygen saturation (SpO2) level during intubation. Secondary outcomes were incidence of desaturation (SpO2<90%) and severe hypoxemia (SpO2<80%) throughout the procedure, intubation time, rate of failed intubation, and 30-day survival rates.

RESULTS

A total of 135 patients were randomized into two groups (HFNC n = 68; BVM n = 67). The median lowest SpO2 value measured during intubation was 96% (88.8%-99.0%) in the HFNC group and 92% (86.0%-97.5%) in the BVM group (P = .161). During the intubation procedure, severe hypoxemia occurred in 13.2% (n = 9) of patients in the HFNC group and 8.9% (n = 6) in the BVM group, while mild hypoxemia was observed in 35.8% (n = 24) of the BVM group and 26.5% (n = 18) of the HFNC group. However, there was no statistically significant difference between the groups in terms of hypoxemia development (P = .429 and P = .241, respectively). No significant difference was reported in the rate of failed intubation between the groups. Thirty-day mortality was observed in 73.1% of the BVM group and 57.4% of the HFNC group, with a borderline statistically significant difference (difference 15.7; 95% CI of the difference: -0.4 to 30.7; P = .054).

CONCLUSION

The use of HFNC for preoxygenation, when compared to standard care with BVM oxygenation, did not improve the lowest SpO2 levels during intubation. Also, the use of HFNC during intubation did not provide benefits in reducing the incidence of severe hypoxemia. However, the 30-day survival rates were slightly better in the HFNC group compared to the BVM group.

Transnasal Humidified Rapid-Insufflation Ventilatory Exchange Versus Conventional Facemask Breathing for Preoxygenation During Rapid Sequence Induction

INTRODUCTION

Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE), if used for pre-oxygenation and apnoeic oxygenation, has the propensity to extend the safe apnoea time and thereby decrease the incidence of desaturation during rapid sequence induction (RSI) for emergency surgeries. Hence, we proposed to evaluate the comparative efficacy of pre-oxygenation with the use of conventional facemask breathing versus THRIVE during RSI in patients undergoing general anaesthesia (GA) for emergency surgeries.

MATERIALS AND METHODS

Eighty patients undergoing RSI under GA for emergency abdominopelvic surgery were divided randomly into two groups. Patients were preoxygenated for three minutes with 100% oxygen via either a high-flow nasal cannula at a flow of 60 L/minute using THRIVE or a tightly-held, snuggly-fitting facemask at a flow of 12L/minute using a circle system. RSI was administered followed by laryngoscopy and endotracheal intubation. Arterial partial pressure of oxygen (PaO2) measured immediately after successful endotracheal intubation was our primary outcome. The lowest peripheral oxygen saturation (SpO2), apnoea time, number of attempts at laryngoscopy, use of any rescue manoeuvres, and any adverse event were also recorded. Data thus collected were statistically analysed.

RESULTS

No statistically significant difference in PaO2 value was observed after successful intubation, lowest SpO2, apnoea time, number of attempts at laryngoscopy, use of any rescue manoeuvres, and adverse event between both the groups (p>0.05).

CONCLUSION

We conclude that though not superior to conventional facemasks, THRIVE is a safe, practicable, and efficient pre-oxygenation tool during RSI of GA for patients undergoing emergency surgeries.

High-Flow Nasal Cannula for Apneic Oxygenation in Obese Patients for Elective Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Obese patients desaturate rapidly during the apneic period after induction of anesthesia for elective surgery. Administration of oxygen using high-flow nasal cannulae (HFNCs) may prevent desaturation in nonobese patients compared to facemask (FM) preoxygenation. The aim of this meta-analysis was to compare the effectiveness of HFNC to FM preoxygenation techniques in reducing preintubation desaturation in obese patients undergoing elective surgery.

METHODS

This study protocol was registered on PROSPERO (CRD42022309391). Adult studies that compared HFNC and FM preoxygenation in obese patients requiring general anesthesia for elective surgery were included. The primary outcome was desaturation resulting in oxygen saturation of <92% from induction of anesthesia until intubation. Secondary outcomes included the lowest arterial oxygen content before intubation expressed in mm Hg, safe apnea time expressed in seconds, the lowest oxygen saturation before intubation expressed as a percentage, patient-reported discomfort, the need for rescue ventilation, and the incidence of aspiration of gastric contents during intubation. Risk of bias was assessed using the Cochrane Collaboration tool. Certainty was assessed following the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

Six studies including 351 participants were eligible for analysis. There was no difference in odds of oxygen desaturation <92% between HFNC and FM (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.15-1.63; P = .24). The HFNC group had a significantly longer safe apnea time (mean difference [MD], -124.20 with 95% CI, -200.47 to -47.93; P = .001). There was no difference between HFNC and FM in the lowest arterial oxygen content (MD, -23.90; 95% CI, -88.64 to 40.85; P = .47) and the lowest peripheral oxygenation saturation (MD, -0.47 with 95% CI, -5.07 to 4.12; P = .84). HFNC had a lower odd of discomfort than FM (OR, 0.13; 95% CI, 0.03-0.52; P = .004). There was no difference in the odds of aspiration of gastric contents between HFNC and FM (OR, 0.33; 95% CI, 0.01-8.21; P = .50). The risk of bias for our primary and secondary outcomes was low. The GRADE assessment for our primary outcome indicated a low level of certainty. For secondary outcomes, the GRADE assessment indicated a very low certainty for all outcomes except for patient discomfort, which was indicated as a moderate level of certainty.

CONCLUSIONS

There may be no difference between HFNC and FM preoxygenation in preventing oxygen desaturation <92% or the lowest oxygen saturation before intubation. Preparation remains important to prevent and manage desaturation during induction of obese patients.

Should We Use High-Flow Nasal Cannula in Patients Receiving Gastrointestinal Endoscopies? Critical Appraisals through Updated Meta-Analyses with Multiple Methodologies and Depiction of Certainty of Evidence

(1) Background: High-flow nasal cannula (HFNC) therapy or conventional oxygen therapy (COT) are typically applied during gastrointestinal (GI) endoscopic sedation. (2) Methods: We conducted a rigorous systematic review enrolling randomized controlled trials (RCTs) from five databases. Risk of bias was assessed using Cochrane's RoB 2.0 tool; certainty of evidence (CoE) was assessed using GRADE framework. Meta-analysis was conducted using inverse-variance heterogeneity model and presented as relative risk (RR) with 95% confidence interval (CI). Trial sequential analysis was performed, and sensitivity analysis was conducted with Bayesian approach. (3) Results: Eight RCTs were included. Compared to COT, HFNC did not reduce the overall incidence of hypoxemia (RR 0.51; 95% CI 0.24-1.09; CoE: very low) but might reduce the incidence of hypoxemia in patients at moderate to high risk for hypoxemia (RR 0.54; 95% CI 0.31-0.96; and CoE: very low). HFNC might reduce the incidence of severe hypoxemia (RR 0.38; 95% CI 0.20-0.74; and CoE: low). HFNC might not affect the need of minor airway interventions (RR 0.31; 95% CI 0.08-1.22; and CoE: very low) and had no effect on procedure duration (CoE: very low); (4) Conclusions: During GI endoscopic sedation, HFNC might reduce the incidence of hypoxemia in patients at moderate to high risk for hypoxemia and prevent severe hypoxemia.

Effectiveness of high-flow nasal cannula for tracheal intubation in the emergency department

Background

Tracheal intubation in the emergency department (ED) can cause serious complications. Available evidence on the use of a high-flow nasal cannula (HFNC) during intubation in the ED is limited. This study evaluated the effect of oxygen therapy by HFNC on oxygen desaturation during tracheal intubation in the ED.

Methods

This was a single-center before-and-after study designed to compare two groups that received oxygen therapy during intubation: one received conventional oxygen, and the other received oxygen therapy using HFNC. We included non-trauma patients who required tracheal intubation in the ED. Linear regression analysis was performed to evaluate the relationship between oxygen therapy using HFNC and the lowest peripheral oxygen saturation (SpO₂) during intubation in the conventional and HFNC groups.

Results

The study population included 87 patients (conventional group, n = 67; HFNC group, n = 20). The median lowest SpO₂ in the HFNC group was significantly higher than that in the conventional group (94% [84–99%] vs. 85% [76–91%], p = 0.006). The percentage of cases with oxygen desaturation to < 90% during the intubation procedure in the HFNC group was significantly lower than that in the conventional group (40% vs. 63.8%, p = 0.037). The use of HFNC was significantly associated with the lowest SpO₂, and the use of HFNC increased the lowest SpO₂ during intubation procedures by 3.658% (p = 0.048).

Conclusion

We found that the use of HFNC during tracheal intubation was potentially associated with a higher lowest SpO₂ during the procedure in comparison to conventional oxygen administration in non-trauma patients in the ED.