Apneic Oxygenation Research Articles

11 The Effect of Apneic Oxygenation on End-Tidal Oxygen Concentration During Rapid Sequence Intubation

11 The Effect of Apneic Oxygenation on End-Tidal Oxygen Concentration During Rapid Sequence Intubation

Apneic Oxygenation: A Narrative Review

Apneic Oxygenation: A Narrative Review

Prospective Evaluation of a Modified Apnea Test in Brain Death Candidates that Does Not Require Disconnection from the Ventilator.

The apnea test (AT) is an important component in the determination of brain death/death by neurologic criteria (BD/DNC) and often entails disconnecting the patient from the ventilator followed by tracheal oxygen insufflation to ensure adequate oxygenation. To rate the test as positive, most international guidelines state that a lack of spontaneous breathing must be demonstrated when the arterial partial pressure of carbon dioxide (PaCO2)≥ 60mm Hg. However, the loss of positive end-expiratory pressure that is associated with disconnection from the ventilator may cause rapid desaturation. This, in turn, can lead to cardiopulmonary instability (especially in patients with pulmonary impairment and diseases such as acute respiratory distress syndrome), putting patients at increased risk. Therefore, this prospective study aimed to investigate whether a modified version of the AT (mAT), in which the patient remains connected to the ventilator, is a safer yet still valid alternative. The mAT was performed in all 140 BD/DNC candidates registered between January 2019 and December 2022: after 10min of preoxygenation, (1) positive end-expiratory pressure was increased by 2mbar (1.5mm Hg), (2) ventilation mode was switched to continuous positive airway pressure, and (3) apnea back-up mode was turned off (flow trigger 10 L/min). The mAT was considered positive when spontaneous breathing did not occur upon PaCO2 increase to ≥ 60mm Hg (baseline 35-45mm Hg). Clinical complications during/after mAT were documented. The mAT was possible in 139/140 patients and had a median duration of 15min (interquartile range 13-19min). Severe complications were not evident. In 51 patients, the post-mAT arterial partial pressure of oxygen (PaO2)was lower than the pre-mAT PaO2, whereas it was the same or higher in 88 cases. In patients with pulmonary impairment, apneic oxygenation during the mAT improved PaO2. In 123 cases, there was a transient drop in blood pressure at the end of or after the mAT, whereas in 12 cases, the mean arterial pressure dropped below 60mm Hg. The mAT is a safe and protective means of identifying patients who no longer have an intact central respiratory drive, which is a critical factor in the diagnosis of BD/DNC. Clinical trial registration DRKS, DRKS00017803, retrospectively registered 23.11.2020, https://drks.de/search/de/trial/DRKS00017803.

Pediatric airway management: A narrative review of the current practices and challenges

Pediatric patients are more susceptible to critical events, the management of their airway necessitates skilled and meticulous interventions. Thus, it is essential to be well versed with the knowledge that can aid in our understanding of the pediatric airway. We conducted a narrative review of the current understanding of pediatric airway assessment techniques, various airway adjuncts and devices, the use of video laryngoscopes for endotracheal intubation and future trends. The databases Ovid, Medline, PubMed, Web of Science, and Google Scholar were searched regarding various aspects of pediatric airway management from 2005 to 2024. The search terms were pediatric or infant difficult airway, pediatric difficult airway, apneic oxygenation, and pediatric airway assessment. One hundred articles were deemed relevant by abstract, and their full text was obtained and examined further for compliance, and finally, 40 full-text articles were included in the study. This article discusses the various challenges of pediatric anesthesia related to airway management, emphasizing the need for individualized perioperative methods due to children’s unique anatomical and physiological features.

Preoxygenation and apneic oxygenation in emergency airway management.

Preoxygenation during the peri-intubation period is now considered a critical aspect of rapid sequence intubation and an important skill for emergency medicine and critical care providers. Peri-intubation hypoxemia carries significant risk, including cardiac arrest, and care must be taken for appropriate management including through apnea and initiation of laryngoscopy. Appropriate selection of preoxygenation devices should depend on underlying physiology to optimize oxygenation prior to intubation attempts. A PubMed MEDLINE search was completed with selection of articles from March 2008 to March 2023 describing various techniques for preoxygenation for intubation in the critical care and operating room setting with pregnant and obese patient populations included. Prehospital and pediatric populations were excluded in this review. This review provides an overview of methods of preoxygenation with their clinical indications as well as methods for determining end points to preoxygenation and apneic oxygenation. An overview of approaches to preoxygenation was included for patients considered to have a physiologically difficult airway and obese and pregnant patient populations.

Use of THRIVE for Apneic Oxygenation in Transoral Laser Microlaryngeal Surgery: A Scoping Review.

Trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) has demonstrated utility in extending the apneic window in the perioperative setting. Its benefits in facilitating tubeless anesthesia are recognized during elective laryngotracheal surgeries. The use of THRIVE and administering higher fractional inspired oxygen concentrations in laser laryngeal surgery (LLS) remains controversial due to the theoretical risk of airway fires. A scoping review of the literature describing institutional experiences with THRIVE during LLS was conducted. A systematic scoping review of the literature was performed including PubMed, Medline, Embase, Scopus, JBI EBP Database, and Cochrane Library from inception to April 2023. From the 472 articles identified in our review, nine articles were included representing 271 cases. THRIVE was used for preoxygenation and to maintain apneic oxygenation during LLS. Different institutional practices related to THRIVE parameters and intraoperative modifications during lasing were described in the literature, including cessation of THRIVE, reduction of FiO2 to 30%, and continuous 100% FiO2 oxygenation. One study described a brief ignition of the coating of a KTP laser fiber without injury to the patient. No adverse patient outcomes have been documented in the literature with THRIVE during LLS. THRIVE is a safe and effective form of tubeless anesthesia and apneic oxygenation during LLS, with no adverse patient safety events reported in the literature. Key determinants to maintain safety include optimal patient and team selection, effective surgeon-anesthetist cooperation, and institutional protocols that govern intraoperative practice. Laryngoscope, 134:4203-4212, 2024.

Effectiveness of trans-nasal humidified rapid insufflation ventilatory exchange compared with standard facemask oxygenation for pre- and apneic oxygenation during anesthesia induction: A meta-analysis based on randomized controlled trials.

To further identify the effectiveness of trans-nasal humidified rapid insufflation ventilatory exchange (THRIVE) for pre- and apneic oxygenation during the anesthesia induction by comparison to facemask ventilation (FMV) based on current available evidence. Medline, EMBASE, Web of Science, Cochrane Library and CNKI databases were searched from inception to December 22, 2023 for available randomized controlled trials (RCTs). Primary outcomes were PaO2 and PaCO2 after intubation and safe apnoea time. Secondary outcomes included the O2 desaturation, end expiratory carbon dioxide (EtCO2) and complications. The effect measures for continuous and categorical outcomes were separately the mean difference (MD) and relative risk (RR) with 95% confidence interval. Twelve RCTs with 403 patients in the THRIVE group and 401 patients in th FMV group were included. Pooled results demonstrated that the PaO2 after intubation was significantly higher (MD = 82.90mmHg, 95% CI: 12.25~153.54mmHg, P = 0.02) and safe apnoea time (MD = 103.81s, 95% CI: 42.07~165.56s, P = 0.001) was longer in the THRIVE group. Besides, the incidence rate of O2 desaturation (RR = 0.28, 95% CI: 0.12-0.66, P = 0.004) and gastric insufflation (RR = 0.26, 95% CI: 0.13-0.49, P<0.001) was significantly lower in the THRIVE group. Based on current evidence, THRIVE manifested better effectiveness representing as improved oxygenation, prolonged safe apnoea time and decreased risk of complications compared to standard FMV in surgical patients. Therefore, THRIVE could be served as a novel and valuable oxygenation technology for patients during anesthesia induction.

Does apneic oxygenation with nasopharyngeal cannula during intubation improve the oxygenation in patients with acute hypoxemic respiratory failure compared to the standard bag valve mask preoxygenation? An open-labeled randomized control trial.

In the context of acute hypoxemic respiratory failure (AHRF), ensuring effective preoxygenation and apneic oxygenation emerges as the pivotal approach ensuring for averting hypoxemic adverse events during endotracheal intubation. To investigate this, we conducted an open-label randomized controlled trial, aiming to assess the comparative effectiveness of nasopharyngeal high-flow oxygenation in conjunction with Bag-Valve-Mask (BVM) versus standard BVM preoxygenation in patients experiencing AHRF within the emergency department (ED). This prospective single-center, open-labeled, randomized controlled trial enrolled patients aged 18 years and above requiring rapid sequence intubation due to AHRF in the ED. Participants were randomly assigned in a 1:1 ratio to either the intervention arm (involving nasopharyngeal high-flow oxygenation and BVM preoxygenation) or the control arm (involving BVM preoxygenation alone). A total of 76 participants were enrolled in the study, evenly distributed with 38 individuals in each arm. Median (interquartile range [IQR]) SpO2 at 0 min postintubation was 95.5 (80%-99%) versus 89 (76%-98%); z-score: 1.081, P = 0.279 in the intervention and control arm, respectively. The most common postintubation complications included hypoxia (intervention arm: 56.7% vs. control arm: 66.7%) and circulatory/hypoxic arrest (intervention arm: 39.5% vs. control arm: 44.7%). There were no adverse complications in 36.7% (n = 11) of patients in the intervention arm. Despite the best possible medical management, almost half (52.6%) of patients in the intervention arm and 47.4% of patients in the control arm succumbed to their illnesses in the ED. The primary outcome revealed no statistically significant difference between the two arms. However, patients in the intervention arm exhibited fewer intubation-related adverse effects.

Intubação de sequência rápida em emergências pediátricas: uma revisão integrativa

Objectives: To identify up-to-date information that contributes to increasing the progress of rapid sequence intubation (RSI) in pediatric emergencies. Methods: This is an integrative literature review that used the keywords “Rapid Sequence Induction and Intubation”, “Intubation, Intratracheal” and “Pediatric Emergency Medicine” in the Scielo, PubMed and Virtual Health Library databases, using, after applying the inclusion and exclusion criteria, the content analysis for discussion. Results: We found 9 articles that were later discussed. Conclusions: Many health professionals do not correctly indicate medications during and after RSI in pediatric emergencies, and educational interventions aimed at correcting this failure are beneficial. An accurate epidemiological profile of RSI in pediatric emergencies cannot yet be established. The best way to collect data in studies involving RSI is through video recording. Interventions aimed at reducing the time spent during orotracheal tube insertion may more effectively reduce the total apnea time during RSI. The use of apneic oxygenation and fractional expired oxygen (FeO2) analysis may have some benefits in RSI.

Personalized Noninvasive Respiratory Support in the Perioperative Setting: State of the Art and Future Perspectives.

Background: Noninvasive respiratory support (NRS), including high-flow nasal oxygen therapy (HFNOT), noninvasive ventilation (NIV) and continuous positive airway pressure (CPAP), are routinely used in the perioperative period. Objectives: This narrative review provides an overview on the perioperative use of NRS. Preoperative, intraoperative, and postoperative respiratory support is discussed, along with potential future areas of research. Results: During induction of anesthesia, in selected patients at high risk of difficult intubation, NIV is associated with improved gas exchange and reduced risk of postoperative respiratory complications. HFNOT demonstrated an improvement in oxygenation. Evidence on the intraoperative use of NRS is limited. Compared with conventional oxygenation, HFNOT is associated with a reduced risk of hypoxemia during procedural sedation, and recent data indicate a possible role for HFNOT for intraoperative apneic oxygenation in specific surgical contexts. After extubation, "preemptive" NIV and HFNOT in unselected cohorts do not affect clinical outcome. Postoperative "curative" NIV in high-risk patients and among those exhibiting signs of respiratory failure can reduce reintubation rate, especially after abdominal surgery. Data on postoperative "curative" HFNOT are limited. Conclusions: There is increasing evidence on the perioperative use of NRS. Use of NRS should be tailored based on the patient's specific characteristics and type of surgery, aimed at a personalized cost-effective approach.

Pre-oxygenation with high-flow oxygen through the nasopharyngeal airway compared to facemask on carbon dioxide clearance in emergency adults: a prospective randomized non-blinded clinical trial

IntroductionBefore tracheal intubation, it is essential to provide sufficient oxygen reserve for emergency patients with full stomachs. Recent studies have demonstrated that high-flow nasal oxygen (HFNO) effectively pre-oxygenates and prolongs apneic oxygenation during tracheal intubation. Despite its effectiveness, the use of HFNO remains controversial due to concerns regarding carbon dioxide clearance. The air leakage and unknown upper airway obstruction during HFNO therapy cause reduced oxygen flow above the vocal cords, possibly weaken the carbon dioxide clearance.MethodsPatients requiring emergency surgery who had fasted < 8 h and not drunk < 2 h were randomly assigned to the high-flow group, who received 100% oxygen at 30–60 L/min through nasopharyngeal airway (NPA), or the mask group, who received 100% oxygen at 8 L/min. PaO2 and PaCO2 were measured immediately before pre-oxygenation (T0), anesthesia induction (T1), tracheal intubation (T2), and mechanical ventilation (T3). The gastric antrum’s cross-sectional area (CSA) was measured using ultrasound technology at T0, T1, and T3. Details of complications, including hypoxemia, reflux, nasopharyngeal bleeding, postoperative pulmonary infection, postoperative nausea and vomiting (PONV), and postoperative nasopharyngeal pain, were recorded. The primary outcomes were PaCO2 measured at T1, T2, and T3. The secondary outcomes included PaO2 at T1, T2, and T3, CSA at T1 and T3, and complications happened during this trial.ResultsPre-oxygenation was administered by high-flow oxygen through NPA (n = 58) or facemask (n = 57) to 115 patients. The mean (SD) PaCO2 was 32.3 (6.7) mmHg in the high-flow group and 34.6 (5.2) mmHg in the mask group (P = 0.045) at T1, 45.0 (5.5) mmHg and 49.4 (4.6) mmHg (P < 0.001) at T2, and 47.9 (5.1) mmHg and 52.9 (4.6) mmHg (P < 0.001) at T3, respectively. The median ([IQR] [range]) PaO2 in the high-flow and mask groups was 404.5 (329.1–458.1 [159.8–552.9]) mmHg and 358.9 (274.0–413.3 [129.0–539.1]) mmHg (P = 0.007) at T1, 343.0 (251.6–428.7 [73.9–522.1]) mmHg and 258.3 (162.5–347.5 [56.0–481.0]) mmHg (P < 0.001) at T2, and 333.5 (229.9–411.4 [60.5–492.4]) mmHg and 149.8 (87.0–246.6 [51.2–447.5]) mmHg (P < 0.001) at T3, respectively. The CSA in the high-flow and mask groups was 371.9 (287.4–557.9 [129.0–991.2]) mm2 and 386.8 (292.0–537.3 [88.3–1651.7]) mm2 at T1 (P = 0.920) and 452.6 (343.7–618.4 [161.6–988.1]) mm2 and 385.6 (306.3–562.0 [105.5–922.9]) mm2 at T3 (P = 0.173), respectively. The number (proportion) of complications in the high-flow and mask groups is shown below: hypoxemia: 1 (1.7%) vs. 9 (15.8%, P = 0.019); reflux: 0 (0%) vs. 0 (0%); nasopharyngeal bleeding: 1 (1.7%) vs. 0 (0%, P = 1.000); pulmonary infection: 4 (6.9%) vs. 3 (5.3%, P = 1.000); PONV: 4 (6.9%) vs. 4 (7.0%, P = 1.000), and nasopharyngeal pain: 0 (0%) vs. 0 (0%).ConclusionsCompared to facemasks, pre-oxygenation with high-flow oxygen through NPA offers improved carbon dioxide clearance and enhanced oxygenation prior to tracheal intubation in patients undergoing emergency surgery, while the risk of gastric inflation had not been ruled out.Trial registrationThis trial was registered prospectively at the Chinese Clinical Research Registry on 26/4/2022 (Registration number: ChiCTR2200059192).

Apneic Oxygenation: A Summarized Review and Stepwise Approach.

Apneic oxygenation is a technique used during airway management procedures to maintain oxygenation and prevent desaturation during a lack of ventilation. Despite its importance, there is a lack of comprehensive information on how to achieve effective apneic oxygenation, leading to misunderstandings and suboptimal utilization of this technique. Apneic oxygenation involves several key steps. Firstly, patient selection is crucial, considering factors such as anticipated difficulty with airway management, reduced functional residual capacity, increased oxygen consumption, and medical conditions associated with impaired oxygenation. Secondly, adequate preoxygenation is essential to optimize oxygen reserves before the onset of apnea, utilizing methods like non-rebreather oxygen masks or specific breathing techniques. Thirdly, maintaining airway patency through techniques such as jaw thrust or nasopharyngeal airway placement allows for unobstructed airflow during the apneic period. Lastly, the selection of the appropriate oxygen delivery method, such as high-flow nasal oxygen or nasal cannula, depends on the patient's existing respiratory support. Despite the growing body of literature on apneic oxygenation, current review articles often lack a stepwise approach for its proper execution. This knowledge gap contributes to the misunderstanding and underutilization of this important tool during intubation and airway management. In conclusion, apneic oxygenation is a valuable technique for maintaining oxygenation during periods of apnea. However, the lack of comprehensive information and stepwise guidance in the current literature hinders its optimal utilization. Clear guidelines and educational resources should be developed to address this knowledge gap and ensure the safe and effective implementation of apneic oxygenation. By following a stepwise approach that includes patient selection, adequate preoxygenation, airway patency, and appropriate oxygen delivery, healthcare providers can enhance patient outcomes and minimize the risk of desaturation during airway management procedures.

Transnasal Humidified Rapid Insufflation Ventilatory Exchange in Endoscopic Esophageal Surgery.

Transnasal humidified rapid insufflation ventilatory exchange (THRIVE) describes apneic oxygenation using humidified high flow nasal-cannula oxygen. Although it has been described as a sole mode of oxygenation in endoscopic laryngotracheal surgery, its use in endoscopic esophageal surgery under general anesthesia with neuromuscular paralysis has not previously been described. The objective of this study is to assess the safety and efficacy of THRIVE in esophagology. We conducted a retrospective review of adult patients undergoing esophageal procedures under general anesthesia who were oxygenated using THRIVE at two academic institutions. Demographic, clinical, and anesthesiologic data were collected and analyzed. 14 cases performed from March 2021 to March 2022 met inclusion criteria. 13/14 (92.9%) of patients were able to maintain oxygenation throughout the entirety of their procedure. The mean apneic time was 17.9 minutes with a maximum of 32 minutes. One patient required "rescue" intubation due to failure to maintain oxygenation. Excluding the sole THRIVE failure, the median SpO2 at the conclusion of surgery was 99% (range 94-100%). A linear regression model yielded an increase in EtCO2 of 0.95 mmHg/min or 0.127 kPa/min. SpO2 was negatively associated with both tobacco pack-year smoking history (R2 = 0.343, P = .014) and BMI (R2 = 0.238, P = .038). THRIVE is a feasible, safe, and efficacious means of apneic oxygenation for patients undergoing esophageal endoscopic surgery under general anesthesia with neuromuscular paralysis, which may be particularly beneficial in patients with airway stenosis, as post-intubation changes can have severe clinical implications for this patient population. Obese patients and tobacco smokers may be at increased risk of oxygen desaturation when using THRIVE.

For adults requiring tracheal intubation, what are the effects of apneic oxygenation before intubation?

For adults requiring tracheal intubation, what are the effects of apneic oxygenation before intubation?

Adverse Tracheal Intubation Events in Critically Ill Underweight and Obese Children: Retrospective Study of the National Emergency Airway for Children Registry (2013-2020).

Extremes of patient body mass index are associated with difficult intubation and increased morbidity in adults. We aimed to determine the association between being underweight or obese with adverse airway outcomes, including adverse tracheal intubation (TI)-associated events (TIAEs) and/or severe peri-intubation hypoxemia (pulse oximetry oxygen saturation < 80%) in critically ill children. Retrospective cohort using the National Emergency Airway for Children registry dataset of 2013-2020. Critically ill children, 0 to 17 years old, undergoing TI in PICUs. None. Registry data from 24,342 patients who underwent TI between 2013 and 2020 were analyzed. Patients were categorized using the Centers for Disease Control and Prevention weight-for-age chart: normal weight (5th-84th percentile) 57.1%, underweight (< 5th percentile) 27.5%, overweight (85th to < 95th percentile) 7.2%, and obese (≥ 95th percentile) 8.2%. Underweight was most common in infants (34%); obesity was most common in children older than 8 years old (15.1%). Underweight patients more often had oxygenation and ventilation failure (34.0%, 36.2%, respectively) as the indication for TI and a history of difficult airway (16.7%). Apneic oxygenation was used more often in overweight and obese patients (19.1%, 19.6%) than in underweight or normal weight patients (14.1%, 17.1%; p < 0.001). TIAEs and/or hypoxemia occurred more often in underweight (27.1%) and obese (24.3%) patients ( p < 0.001). TI in underweight children was associated with greater odds of adverse airway outcome compared with normal weight children after adjusting for potential confounders (underweight: adjusted odds ratio [aOR], 1.09; 95% CI, 1.01-1.18; p = 0.016). Both underweight and obesity were associated with hypoxemia after adjusting for covariates and site clustering (underweight: aOR, 1.11; 95% CI, 1.02-1.21; p = 0.01 and obesity: aOR, 1.22; 95% CI, 1.07-1.39; p = 0.002). In underweight and obese children compared with normal weight children, procedures around the timing of TI are associated with greater odds of adverse airway events.

THRIVE combined with i-gel laryngeal mask for prolonging apneic oxygenation time in retrograde intrarenal surgery

To explore the effect of THRIVE combined with i-gel laryngeal mask on the safety of oxygen therapy in apnea and surgical precision of retrograde intrarenal surgery. A total of 120 patients undergoing retrograde intrarenal surgery under general anesthesia with laryngeal mask were randomized into 3 groups (n=40), and after the flexible ureteroscope entered the renal pelvis and located the stones, the patients received assisted ventilation in APPV mode (control group), ventilation with small tidal volume and high respiratory rate (group H), or THRIVE combined with laryngeal mask for oxygen supply without using the ventilator (THRIVE group). The time for lithotripsy by the surgeons, surgeons' satisfaction, diaphragm mobility, and times of urinary tract mucosal injury were recorded, and arterial blood pressure, heart rate, SpO2, PaO2, PaCO2, and pH value were measured before, during and after lithotripsy. Among the 3 groups, THRIVE group had the shortest time for lithotripsy, best satisfaction of the surgeons, the lowest diaphragmatic mobility of the patients, and the smallest number of mucosal injuries. The arterial blood pressure, heart rate, and SpO2 of the patients did not differ significantly among the 3 groups. At 20 min and 30 min after the start of lithotripsy, PaO2 decreased significantly in group H and THRIVE group; in THRIVE group, PaCO2 increased and pH decreased significantly at 10, 20 and 30 min after the start of lithotripsy. No significant difference was found in oxygenation indicators among the 3 groups upon discharge from the PACU. In retrograde intrarenal surgery, THRIVE combined with i- gel laryngeal mask for oxygen therapy during the anaerobic period can improve the surgical accuracy and maintain the patient's oxygenation index in a controllable range within 30 min.

Effectiveness of high-flow nasal cannula oxygen in apneic oxygenation during intubation in high-risk surgical patients: a systematic review protocol.

This review will investigate the effectiveness of high-flow nasal oxygen in apneic oxygenation through safe apnea time and other ventilation parameters in patients at high risk of oxygen desaturation during induction and tracheal intubation for anesthesia management. High-risk surgical patient groups include obese patients, those with suspected or known obstructive sleep apnea, and critically ill patients, who are at risk of rapid oxygen desaturation during intubation. Conventional oxygen administration in induction and intubation of patients undergoing general anesthesia include nasal cannulas, simple face masks, Venturi, buccal oxygenation, bag-valve mask ventilation, and non-invasive ventilation. High-flow nasal oxygen has emerged as a novel technique, and is advantageous because it increases positive end-expiratory pressure and oxygen delivered. Eligible studies will include high-risk surgical patients aged 18 or above requiring endotracheal intubation in both emergency and elective anesthetic settings. High-risk patients are defined as those with suspected or known obstructive sleep apnea, obesity (BMI > 35), or critically ill patients (scored the American Society of Anesthesiologists classification as 3 or above). The review will follow the JBI methodology for systematic reviews of effectiveness. Databases to be searched include MEDLINE, Embase, and Scopus. Reference lists of selected studies will then be hand-searched for additional eligible studies. The primary outcome will be safe apnea time, with secondary outcomes including oxygen and carbon dioxide parameters, and adverse events (eg, gastric distension). Studies will, where possible, be pooled in statistical meta-analyses with data heterogeneity assessed using the standard χ2 and I2 tests. PROSPERO CRD42022312145.

The efficacy of apneic oxygenation during intubation using a prototype of an oxygenation laryngoscope - a technical simulation

BackgroundRecently, a non-commercial oxygenation laryngoscope was able to maintain apneic oxygenation during simulated intubation efforts. Since that prototype was 3 mm wider than a standard Macintosh laryngoscope blade, the intubation performance of this device may differ from standard blades. A new prototype of an oxygenation laryngoscope was developed, consisting of a standard-size Macintosh blade and a fixed oxygen supply line to the side. Actually, it is unclear at which point of this blade the oxygen supply line should end to facilitate the best possible oxygen supply for apneic oxygenation.MethodsIn this simulation study using a standardized human airway manikin, the efficacy of apneic oxygenation by oxygen insufflation using standard and modified Macintosh blades was compared: a standard Macintosh blade without oxygen supply line as control, one with an additional oxygen supply line ending proximal near the handle, one with the line ending at the middle of the blade, and one with the line ending near the tip. A preoxygenated test lung was connected to an oximeter with a flow rate of 200ml/min, simulating oxygen consumption of a male adult, and to the trachea of an anatomically correctly shaped airway manikin. Apneic oxygenation was performed and oxygen content was measured over a 20-minutes observation period. Experiments were repeated five times for each laryngoscope blade.ResultsOxygen percentage in the test lung dropped from 100 ± 0% at the start of the experiment to 53 ± 1.5% in the room air control group (p < 0.001 compared to all other groups), and to 74 ± 2.5% in the proximal oxygen line group, whereas oxygen percentage remained at 100% in both the medium and distal oxygen line groups (p = 1 between these groups; p < 0.001 between all other groups).ConclusionsIn this simulation study with a preoxygenated airway manikin, the use of a modified Macintosh laryngoscope blade with oxygen line attached at the tip or at the middle were able to maintain apneic oxygenation without measurable drop of oxygen content over 20 min. Proximal placement of the oxygen supply line still showed an advantage against room air, however it did not completely prevent room air from entering the airway.Trial registrationNot applicable.

Comparative efficacy of apneic oxygenation with face mask versus face mask alone pre-oxygenation to Prevent desaturation during endotracheal intubation of elective Pediatric surgical patients at St. Peter hospital, Addis Ababa Ethiopia:A single center prospective cohort study

BackgroundApneic oxygenation using a nasal cannula is used to deliver oxygen continuously during the apneic period of endotracheal intubation to prevent desaturation. Pre-oxygenation using face mask alone technique may be insufficient to provide a safe apnea period in pediatric patients who are at high risk for rapid desaturation compared to added apneic oxygenation. This study compared the efficacy of apneic oxygenation with a face mask (AO) versus a face mask alone (FMA) pre-oxygenation to prevent desaturation during endotracheal intubation in elective pediatric surgical patients. MethodsA prospective cohort study was conducted on two equal groups of elective pediatric patients observed in either use of apneic oxygenation with a face mask (AO) or face mask alone(FMA) pre-oxygenation during endotracheal intubation at the study hospital from early December 2021 to late March 2022. The data were collected using a structured questionnaire. The primary outcome variable was the desaturation SpO2 (<94%) observed during endotracheal intubation. The categorical data were analyzed using a χ2-test. Parametric data were analyzed using an independent t-test or one-way ANOVA as appropriate with a 95% CI and a p-value of < 0.05 was considered statistically significant. The Bonferroni post hoc analysis was employed to test the significance of means between the groups. ResultsThe mean desaturation level was (SpO2 = 95.74 ± 2.99) in apneic oxygenation with face-mask group and (SpO2 = 93.96 ± 3.74) in the face-mask alone group(p = 0.006) with medium effect size (Cohan's d = 0.06). A one-way ANOVA showed a statistically significant difference in the mean (±SD) of desaturation level with the number of attempts at endotracheal intubation within the groups (P = 0.005). The Bonferroni pairwise comparison within groups, showed that the mean (±SD) desaturation level during endotracheal intubation for the participant with >2 attempts is significantly lower than for participants with only 1 attempt (p-value = 0.004). Conclusion and recommendationA continuous administration of apneic oxygenation (5-l/min) by nasal cannula during endotracheal intubation significantly reduced desaturation in pediatrics. We recommend the use of apneic oxygenation (AO) in pediatrics during intubation time.

The effect of intraoperative transnasal humidified rapid-insufflation ventilatory exchange on emergence from general anesthesia in patients undergoing microlaryngeal surgery: a randomized controlled trial

BackgroundTransnasal humidified rapid-insufflation ventilatory exchange (THRIVE) has received extensive attention for its utility in tubeless anesthesia. Still, the effects of its carbon dioxide accumulation on emergence from anesthesia have not been reported. This randomized controlled trial aimed at exploring the impact of THRIVE combined with laryngeal mask (LM) on the quality of emergence in patients undergoing microlaryngeal surgery.MethodsAfter research ethics board approval, 40 eligible patients receiving elective microlaryngeal vocal cord polypectomy were randomly allocated 1:1 to two groups, THRIVE + LM group: intraoperative apneic oxygenation using THRIVE followed by mechanical ventilation through a laryngeal mask in the post-anesthesia care unit (PACU), or MV + ETT group: mechanically ventilated through an endotracheal tube for both intraoperative and post-anesthesia periods. The primary outcome was duration of PACU stay. Other parameters reflecting quality of emergence and carbon dioxide accumulation were also recorded.ResultsDuration of PACU stay (22.4 ± 6.4 vs. 28.9 ± 8.8 min, p = 0.011) was shorter in the THRIVE + LM group. The incidence of cough (2/20, 10% vs. 19/20, 95%, P < 0.001) was significantly lower in the THRIVE + LM group. Peripheral arterial oxygen saturation and mean arterial pressure during intraoperative and PACU stay, Quality of Recovery Item 40 total score at one day after surgery and Voice Handicap Index-10 score at seven days after surgery were of no difference between two groups.ConclusionsThe THRIVE + LM strategy could accelerate emergence from anesthesia and reduce the incidence of cough without compromising oxygenation. However, these benefits did not convert to the QoR-40 and VHI-10 scores improvement.Trial registrationChiCTR2000038652.