Apnoeic oxygenation by nasal cannula during airway management in children undergoing general anaesthesia: a pilot randomised controlled trial

Apnoeic oxygenation during paediatric tracheal intubation: a systematic review and meta-analysis

BACKGROUND

Supplemental oxygen administration by apnoeic oxygenation during laryngoscopy for tracheal intubation is intended to prolong safe apnoea time, reduce the risk of hypoxaemia, and increase the success rate of first-attempt tracheal intubation under general anaesthesia. This systematic review examined the efficacy and effectiveness of apnoeic oxygenation during tracheal intubation in children.

METHODS

This systematic review and meta-analysis included randomised controlled trials and non-randomised studies in paediatric patients requiring tracheal intubation, evaluating apnoeic oxygenation by any method compared with patients without apnoeic oxygenation. Searched databases were MEDLINE, Embase, Cochrane Library, CINAHL, ClinicalTrials.gov, International Clinical Trials Registry Platform (ICTRP), Scopus, and Web of Science from inception to March 22, 2023. Data extraction and risk of bias assessment followed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) recommendation.

RESULTS

After initial selection of 40 708 articles, 15 studies summarising 9802 children were included (10 randomised controlled trials, four pre-post studies, one prospective observational study) published between 1988 and 2023. Eight randomised controlled trials were included for meta-analysis (n=1070 children; 803 from operating theatres, 267 from neonatal intensive care units). Apnoeic oxygenation increased intubation first-pass success with no physiological instability (risk ratio [RR] 1.27, 95% confidence interval [CI] 1.03-1.57, P=0.04, I2=0), higher oxygen saturation during intubation (mean difference 3.6%, 95% CI 0.8-6.5%, P=0.02, I2=63%), and decreased incidence of hypoxaemia (RR 0.24, 95% CI 0.17-0.33, P<0.01, I2=51%) compared with no supplementary oxygen administration.

CONCLUSION

This systematic review with meta-analysis confirms that apnoeic oxygenation during tracheal intubation of children significantly increases first-pass intubation success rate. Furthermore, apnoeic oxygenation enables stable physiological conditions by maintaining oxygen saturation within the normal range.

CLINICAL TRIAL REGISTRATION

Protocol registered prospectively on PROSPERO (registration number: CRD42022369000) on December 2, 2022.

Apnoeic oxygenation during neonatal intubation

'Apnoeic oxygenation' describes the diffusion of oxygen across the alveolar-capillary interface in the absence of tidal respiration. Apnoeic oxygenation requires a patent airway, the diffusion of oxygen to the alveoli, and cardiopulmonary circulation. Apnoeic oxygenation has varied applications in adult medicine including facilitating tubeless anaesthesia or improving oxygenation when a difficult airway is known or anticipated. In the paediatric population, apnoeic oxygenation prolongs the time to oxygen desaturation, facilitating intubation. This application has gained attention in neonatal intensive care where intubation remains a challenging procedure. Difficulties are related to the infant's size and decreased respiratory reserve. In addition, policy changes have led to limited opportunities for operators to gain proficiency. Until recently, evidence of benefit of apnoeic oxygenation in the neonatal population came from a small number of infants recruited to paediatric studies. Evidence specific to neonates is emerging and suggests apnoeic oxygenation may increase intubation success and limit physiological instability during the procedure. The best way to deliver oxygen to facilitate apnoeic oxygenation remains an important question.

Apneic oxygenation with low-flow oxygen cannula for rapid sequence induction and intubation in pediatric patients: a randomized-controlled trial

BACKGROUND

Classical rapid sequence induction and intubation (RSII) is used to reduce pulmonary aspiration, but it increases the risk of hypoxemia. Apneic oxygenation (ApOx) has been studied to prolong safe apneic time, and to decrease the incidence of hypoxemia in adults. The aim of this study was to investigate the effectiveness of ApOx via low-flow nasal cannula to reduce the incidence of hypoxemia in pediatric rapid sequence induction.

METHODS

This prospective single-blind randomized controlled trial included patients aged 0-7 years, American Society of Anesthesiologists (ASA) physical status 1 to 3, who underwent elective or emergency surgery under general anesthesia with rapid sequence induction during February 2020 to March 2021. Participants were randomized to the ApOx group or the classical rapid sequence induction group. The ApOx group received oxygen flow via regular nasal cannula, as follows: 1 liter per minute (LPM) in age 0-1 month, 2 LPM in age 1-12 months, and 4 LPM in age 1-7 years. The classical group did not receive oxygen supplementation during intubation. The primary outcome was the incidence of hypoxemia, defined as oxygen saturation (SpO₂) ≤92%.

RESULTS

Sixty-four participants were recruited. The incidence of hypoxemia in both groups was 8 of 32 participants (25%) (P=1.000). Among desaturated patients, the median time to desaturation was 29.5 and 35 seconds in the ApOx and classical groups, respectively (P=0.527). The median lowest SpO₂ was 91% and 88.5% in the ApOx and classical groups, respectively (P=0.079). In non-desaturated patients, the median time to successful intubation was 40.5 and 35.5 seconds in the ApOx and classical groups, respectively (P=0.069).

CONCLUSIONS

In this small sample study, ApOx using age-adjusted low-flow nasal cannula was ineffective for reducing the incidence of hypoxemia in pediatric RSII.

TRIAL REGISTRATION

Thai Clinical Trials Registry TCTR20210802002.

Apnoeic oxygenation during paediatric intubation: A systematic review

OBJECTIVE

This review assesses the effect of apnoeic oxygenation during paediatric intubation on rates of hypoxaemia, successful intubation on the first attempt and other adverse events.

DATA SOURCES

The databases searched included PubMed, Medline, CINAHL, EMBASE and The Cochrane Library. An electronic search for unpublished studies was also performed.

STUDY SELECTION

We screened studies that include children undergoing intubation, studies that evaluate the use of apnoeic oxygenation by any method or device with outcomes of hypoxaemia, intubation outcome and adverse events were eligible for inclusion.

DATA EXTRACTION

Screening, risk of bias, quality of evidence and data extraction was performed by two independent reviewers, with conflicts resolved by a third reviewer where consensus could not be reached.

DATA SYNTHESIS

From 362 screened studies, fourteen studies (N = 2442) met the eligibility criteria. Randomised controlled trials (N = 482) and studies performed in the operating theatre (N = 835) favoured the use of apnoeic oxygenation with a reduced incidence of hypoxaemia (RR: 0.34, 95% CI: 0.24 to 0.47, p < 0.001, I ² = 0% and RR: 0.27, 95% CI: 0.11 to 0.68, p = 0.005, I ² = 68% respectively). Studies in the ED and PICU were of lower methodological quality, displaying heterogeneity in their results and were unsuitable for meta-analysis. Among the studies reporting first attempt intubation success, there were inconsistent effects reported and data were not suitable for meta-analysis.

CONCLUSION

There is a growing body of evidence to support the use of apnoeic oxygenation during the intubation of children. Further research is required to determine optimal flow rates and delivery technique. The use of humidified high-flow oxygen shows promise as an effective technique based on data in the operating theatre, however its efficacy has not been shown to be superior to low flow oxygen in either the elective anesthetic or emergency intubation situations Systematic Review Registration: This review was prospectively registered in the PROSPERO international register of systematic reviews (Reference: CRD42020170884, registered April 28, 2020).

The role of bronchoscopy in the diagnosis and management of pediatric pulmonary tuberculosis

Bronchoscopy is useful as a diagnostic and therapeutic procedure in children with Tuberculosis (TB) disease complicated by airway obstruction. It is needed in children when surgical intervention may be required for airway compression, when drug resistance is suspected, and to rule out an alternative diagnosis for airway obstruction. Bronchoscopy with bronchoalveolar lavage (BAL) should be performed when other, less invasive samples cannot be collected, or when they fail to provide useful diagnostic information. BAL specimens collected at bronchoscopy can be tested using molecular TB assays and mycobacterial culture. The aim of this review is to evaluate the role of bronchoscopy in the diagnosis and management of pulmonary TB in children, and, specifically, to review the role of interventional bronchoscopy. A search of electronic databases was undertaken using the online databases PubMed, Ovid MEDLINE, EMBASE, Google Advanced Scholar, and Web of Science to identify relevant literature. The search was limited to pediatrics, pulmonology, bronchoscopy, and pediatric pulmonary tuberculosis for all articles published in English on pediatric bronchoscopy between 2010 and 2020. Recent advances in pediatric bronchoscopy was included, as well as recent research on improving the diagnosis with the use of interventional bronchoscopy. The role of bronchoscopy in pediatric pulmonary tuberculosis has changed during the last decade, from a simple method of collecting samples for bacteriological conformation to an more sophisticate procedure. New methods are available for collecting samples, which includes the use of Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and also better methods of bacteriological conformation. Interventions are now possible; not only to improve the diagnostic abilities of bronchoscopy but also to diagnose, manage, and follow-up upon airway-related complications. Bronchoscopy services remain limited in resource-limited countries due to the high cost of equipment.

Emerging trends, techniques, and equipment for airway management in pediatric patients

Pediatric patients present unique anatomic and physiologic considerations in airway management, which impose significant physiologic limits on safe apnea time before the onset of hypoxemia and subsequent bradycardia. These issues are even more pronounced for the pediatric difficult airway. In the last decade, the development of pediatric sized supraglottic airways specifically designed for intubation, as well as advances in imaging technology such that current pediatric airway equipment now finally rival those for the adult population, has significantly expanded the pediatric anesthesiologist's tool kit for pediatric airway management. Equally important, techniques are increasingly implemented that maintain oxygen delivery to the lungs, safely extending the time available for pediatric airway management. This review will focus on emerging trends and techniques using existing tools to safely handle the pediatric airway including videolaryngoscopy, combination techniques for intubation, techniques for maintaining oxygenation during intubation, airway management in patients at risk for aspiration, and considerations in cannot intubate cannot oxygenate scenarios.

Apneic Oxygenation for Pediatric Endotracheal Intubation: A Narrative Review

Apneic oxygenation (ApOx) has shown to be effective in adult populations in a variety of settings, including prehospital, emergency departments, intensive care units, and elective surgery. This review aims to assess the available literature for ApOx in the pediatric population to determine its effects on hypoxemia, safe apnea times, and flow rates employed safely.