High-flow nasal cannula oxygen therapy and hypoxia during gastroscopy with propofol sedation: a randomized multicenter clinical trial

Comparing oxygen therapies for hypoxemia prevention during gastrointestinal endoscopy under procedural sedation: A systematic review and network meta-analysis

STUDY OBJECTIVE

Hypoxemia is the most frequent adverse event observed during gastrointestinal endoscopy under procedural sedation. An optimum oxygen therapy has still not been conclusively determined.

DESIGN

A systematic review and network meta-analysis of randomized clinical trials.

SETTING

Digestive Endoscopy Center.

PATIENTS

Adults (≥18 years old and of both sexes) during gastrointestinal endoscopy under procedural sedation.

INTERVENTIONS

Pubmed, MEDLINE, Web of Science, Embase, and Clinicaltrials.gov. were searched until June 30, 2023. Randomized clinical trials (RCTs) comparing any oxygen therapy with another oxygen therapy or with placebo (nasal cannula, NC) were included.

MEASUREMENT

The primary outcome was the incidence of hypoxemia, defined as the pulse oxygen saturation (SpO2). Random-effects network meta-analyses were performed. Data are reported as odds ratios (OR), prediction intervals (PrI) and 95% CI. Bias risk was evaluated following the guidelines outlined by the Cochrane Collaboration. The quality of evidence was evaluated through the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

MAIN RESULTS

We included 27 RCTs with a total of 7552 patients. Compared to the use of NC, non-invasive positive pressure ventilation (NIPPV) demonstrated superior efficacy in mitigating hypoxemia (NIPPV vs. NC, OR = 0.16, 95% CI: 0.08-0.31, 95% PrI: 0.06-0.41), followed by Wei nasal jet tube (WNJT) (WNJT vs. NC, OR = 0.17, 95% CI: 0.10-0.30, 95% PrI: 0.07-0.42). The efficacy for preventing hypoxemia was ranked as follows: NIPPV > WNJT > oropharynx/nasopharyngeal catheter > high-flow nasal oxygenation > nasal mask > NC.

CONCLUSIONS

During gastrointestinal endoscopy under procedural sedation, all other advanced oxygen therapies were found to be more efficacious than nasal cannula. NIPPV and WNJT appear to be the most efficacious oxygen therapy for preventing hypoxemia. Additionally, clinicians should make a choice regarding the most suitable oxygen therapy based on the risk population, type of endoscopy and adverse events.

Place of high-flow nasal oxygen in nonoperating room anesthesia

PURPOSE OF REVIEW

This article aims to assess the utility of high-flow nasal oxygen (HFNO) therapy in nonoperating room anesthesia (NORA) settings.

RECENT FINDINGS

The number of procedural interventions under deep sedation in NORA is still increasing. Administration of oxygen is recommended to prevent hypoxemia and is usually delivered with standard oxygen through nasal cannula or a face mask. HFNO is a simple alternative with a high warmed humidified flow (ranging from 30 to 70 l/min) with a precise fraction inspired of oxygen (ranging from 21 to 100%). Compared to standard oxygen, HFNO has demonstrated efficacy in reducing the incidence of hypoxemia and the need for airway maneuvers. Research on HFNO has primarily focused on its application in gastrointestinal endoscopy procedures. Yet, it has also shown promising results in various other procedural interventions including bronchoscopy, cardiology, and endovascular procedures. However, the adoption of HFNO prompted considerations regarding cost-effectiveness and environmental impact.

SUMMARY

HFNO emerges as a compelling alternative to conventional oxygen delivery methods for preventing hypoxemia during procedural interventions in NORA. However, its utilization should be reserved for patients at moderate-to-high risk to mitigate the impact of cost and environmental factors.

A meta-analysis of the effects of transnasal high-flow oxygen therapy in gastrointestinal endoscopy

Purpose

This study aimed to systematically evaluate the clinical effects of using transnasal high-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) in patients undergoing gastrointestinal endoscopy.

Methods

A comprehensive literature search was conducted from 2004 to April 2024 to collect relevant studies on the application of HFNC in patients undergoing gastrointestinal endoscopy. Multiple Chinese and English databases, including China National Knowledge Infrastructure (CNKI), Wanfang Data, Web of Science, PubMed, and Cochrane Library, were searched systematically for randomized controlled trials (RCTs). Two researchers independently screened the literature, extracted data, and assessed the risk of bias in the included studies. RevMan 5.4 software was utilized for conducting the network meta-analysis.

Results

A total of 12 RCTs involving 3,726 patients were included. Meta-analysis results showed that HFNC reduced the incidence of hypoxemia and improved the minimum oxygen saturation (SpO2) compared with COT [odds ratio (OR) = 0.39, 95% confidence interval (CI): 0.29-0.53], [mean difference (MD) = 4.07, 95% CI: 3.14-5.01], and the difference was statistically significant. However, the baseline SpO2 levels and incidence of hypercapnia were not statistically significantly different between the HFNC and COT groups [MD = -0.21, 95% CI: -0.49-0.07]; [OR = 1.43, 95% CI: 0.95-2.15]. In terms of procedure time, the difference between HFNC and COT was not statistically significant, and subgroup analyses were performed for the different types of studies, with standard deviation in the gastroscopy group (MD = 0.09, 95% CI: -0.07-0.24) and the endoscopic retrograde cholangiopancreatography group (MD = 0.36, 95% CI: -0.50-1.23). The results demonstrated a significant reduction in the adoption of airway interventions in the HFNC group compared to the COT group (OR = 0.16, 95% CI: 0.05-0.53), with a statistically significant difference; this result was consistent with those of the included studies.

Conclusion

The application of HFNC improves the incidence of hypoxemia, enhances oxygenation, and reduces airway interventions during gastrointestinal endoscopy. However, HFNC does not significantly affect baseline SpO2, hypercapnia, or procedure time. The limitations of this study must be acknowledged, and further high-quality studies should be conducted to validate these findings.

Duration-Dependent Risk of Hypoxemia in Colonoscopy Procedures

Background and Aims: Colonoscopy is a critical diagnostic and therapeutic procedure in gastroenterology. However, it carries risks, including hypoxemia, which can impact patient safety. Understanding the factors that contribute to the incidence of severe hypoxemia, specifically the role of procedure duration, is essential for improving patient outcomes. This study aims to elucidate the relationship between the length of colonoscopy procedures and the occurrence of severe hypoxemia. Methods: We conducted a retrospective cohort study at Sheba Medical Center, Israel, including 21,524 adult patients who underwent colonoscopy from January 2020 to January 2024. The study focused on the incidence of severe hypoxemia, defined as a drop in oxygen saturation below 90%. Sedation protocols, involving a combination of Fentanyl, Midazolam, and Propofol were personalized based on the endoscopist's discretion. Data were collected from electronic health records, covering patient demographics, clinical scores, sedation and procedure details, and outcomes. Statistical analyses, including logistic regression, were used to examine the association between procedure duration and hypoxemia, adjusting for various patient and procedural factors. Results: We initially collected records of 26,569 patients who underwent colonoscopy, excluding 5045 due to incomplete data, resulting in a final cohort of 21,524 patients. Procedures under 20 min comprised 48.9% of the total, while those lasting 20-40 min made up 50.7%. Only 8.5% lasted 40-60 min, and 2.9% exceeded 60 min. Longer procedures correlated with higher hypoxemia risk: 17.3% for <20 min, 24.2% for 20-40 min, 32.4% for 40-60 min, and 36.1% for ≥60 min. Patients aged 60-80 and ≥80 had increased hypoxemia odds (aOR 1.1, 95% CI 1.0-1.2 and aOR 1.2, 95% CI 1.0-1.4, respectively). Procedure durations of 20-40 min, 40-60 min, and over 60 min had aORs of 1.5 (95% CI 1.4-1.6), 2.1 (95% CI 1.9-2.4), and 2.4 (95% CI 2.0-3.0), respectively. Conclusions: The duration of colonoscopy procedures significantly impacts the risk of severe hypoxemia, with longer durations associated with higher risks. This study underscores the importance of optimizing procedural efficiency and tailoring sedation protocols to individual patient risk profiles to enhance the safety of colonoscopy. Further research is needed to develop strategies that minimize procedure duration without compromising the quality of care, thereby reducing the risk of hypoxemia and improving patient safety.

Comparison of high-flow nasal cannula and conventional nasal cannula during deep sedation for endoscopic submucosal dissection: a randomized controlled trial

PURPOSE

Adequate oxygenation and airway management during deep sedation can be challenging. We investigated the effect of high-flow nasal cannula (group HF) and conventional nasal cannula (group CO) during sedation for endoscopic submucosal dissection (ESD).

METHODS

Patients undergoing ESD with deep sedation were enrolled. The primary outcome was difference in lowest oxygen saturation (SpO2) between the groups. Incidence of hypoxia (SpO2 < 90%), patients with SpO2 < 95%, hypercapnia, and airway interventions; operator satisfaction; and adverse events were recorded.

RESULTS

Thirty-two patients in each group completed the study. The mean of minimum SpO2 values was significantly higher in group HF than in group CO (96.8% ± 4.2% vs. 93.3% ± 5.3%, p = 0.005). The incidence of hypoxia was comparable between the groups (4 [12.5%] vs. 6 [18.8%], p = 0.491); however, patients with SpO2 < 95% were significantly less in group HF (5 [15.6%] vs. 18 [56.3%], p = 0.003). Incidence of hypercapnia was higher in group HF than in group CO (14 [46.7%] vs. 5 [16.7%], p = 0.013). Airway rescue interventions were significantly less common in group HF. Satisfaction of operators and post-procedural complications were comparable between the two groups. In multivariable analysis, group CO and higher body mass index were risk factors for airway managements (odds ratio [95% confidence interval]: 6.204 [1.784-21.575], p = 0.004; 1.337 [1.043-1.715], p = 0.022, respectively).

CONCLUSIONS

Compared to conventional nasal cannula, high-flow nasal cannula maintained higher minimum SpO2 value during deep sedation with propofol-remifentanil for ESD.

TRIAL REGISTRATION

Clinical Trial Registry of the Republic of Korea (KCT0006618, https://cris.nih.go.kr ; registered September 29, 2021; principal investigator: Ji Won Choi).

Bilevel positive airway pressure ventilation in patients susceptible to hypoxemia during procedural sedation for colonoscopy: a prospective randomized controlled study

BACKGROUND AND AIMS

Hypoxemia is one of the most common adverse events during colonoscopy, particularly among patients who are diagnosed with obstructive sleep apnea (OSA) or are overweight. Consequently, the objective of this study was to evaluate the effectiveness of bilevel positive airway pressure (BPAP) ventilation for patients with high-risk hypoxemia during colonoscopy with sedation.

METHODS

In this trial, 127 patients who met the eligibility criteria were randomly assigned to the BPAP oxygen group and nasal cannula (NC) group. The primary endpoint was the incidence of hypoxemia.

RESULTS

Compared with the use of NC, BPAP ventilation exhibited a significant reduction in the incidence of hypoxemia, decreasing it from 23.8% to 6.3% (absolute risk difference, 17.5%; 95% confidence interval, 5.4-29.6; P = .006). Importantly, BPAP ventilation prevented the occurrence of severe hypoxemia (9.5% vs 0%; absolute risk difference, 9.5%; 95% confidence interval, 2.3-16.7; P = .035). In addition, the BPAP group required fewer airway interventions (P < .05).

CONCLUSIONS

In individuals with OSA or overweight status, the use of BPAP ventilation during colonoscopy significantly reduced the incidence of hypoxemia. (Clinical trial registration number: ChiCTR2300073193.).

High-flow nasal cannula oxygen reduced hypoxemia in patients undergoing gastroscopy under general anesthesia at ultra-high altitude: a randomized controlled trial

BACKGROUND

Hypoxemia can occur in people at ultra-high altitude (above 3500 m) even at rest, and patients undergoing gastroscopy under general anesthesia have higher risk of hypoxemia. Supplementary oxygen via standard nasal cannula (SNC) is the standard of care for most patients who undergo gastroscopy under general anesthesia, which provides oxygen flow up to 15 L/min. High-flow nasal cannula (HFNC) could deliver oxygen at a rate up to 60 L/min, which is recommended by the American Society of Anesthesiologists Practice Guidelines. We speculated that the benefit with HFNC is more prominent in high-altitude areas, and aimed to compare the incidence of hypoxemia during gastroscopy under general anesthesia at ultra-high altitude with oxygen supply via either HFNC or SNC.

METHODS

The trial was registered at at Chinese Clinical Trial Registry (ChiCTR2100045513; date of registration on 18/04/2021). Adult patients undergoing gastroscopy with anesthesia (estimated duration of anesthesia at ≥ 15 min) were randomized at a 1:1 ratio to receive HFNC oxygen or SNC oxygen. The primary outcome was hypoxemia (SpO2 < 90% for any duration). Secondary outcomes included severe hypoxemia (SpO2 < 75% for any duration or SpO2 < 90% but ≥ 75% for ≥ 60 s) and hypotension, as defined by reduction of mean arterial blood pressure by ≥ 25% from the baseline.

RESULTS

A total of 262 patients were enrolled: 129 in the HFNC group and 133 in the SNC group. All patients received the designated intervention. Student's t-test, Mann-Whitney U test and χ2 test were employed in the study. The rate of hypoxemia was 9.3% (12/129) in the HFNC group versus 36.8% (49/133) in the SNC group [risk ratio (95% confidence interval): 0.25(0.14-0.45); P < 0.001). The HFNC group also had lower rate of severe hypoxemia [0.0% (0/129) versus 11.3% (15/133); risk ratio (95% confidence interval): 0.03(0.00-0.55); P < 0.001, respectively]. The rate of hypotension did not differ between the 2 groups [22.5% (29/129) in HFNC group versus 21.1% (28/133) in SNC group; risk ratio (95% confidence interval): 1.07(0.67-1.69) ; P = 0.779].

CONCLUSION

HFNC oxygen reduced the incidence of hypoxemia during anesthesia in adult patients undergoing gastroscopy at ultra-high altitude.

British Society of Gastroenterology guidelines on sedation in gastrointestinal endoscopy

Over 2.5 million gastrointestinal endoscopic procedures are carried out in the United Kingdom (UK) every year. Procedures are carried out with local anaesthetic r with sedation. Sedation is commonly used for gastrointestinal endoscopy, but the type and amount of sedation administered is influenced by the complexity and nature of the procedure and patient factors. The elective and emergency nature of endoscopy procedures and local resources also have a significant impact on the delivery of sedation. In the UK, the vast majority of sedated procedures are carried out using benzodiazepines, with or without opiates, whereas deeper sedation using propofol or general anaesthetic requires the involvement of an anaesthetic team. Patients undergoing gastrointestinal endoscopy need to have good understanding of the options for sedation, including the option for no sedation and alternatives, balancing the intended aims of the procedure and reducing the risk of complications. These guidelines were commissioned by the British Society of Gastroenterology (BSG) Endoscopy Committee with input from major stakeholders, to provide a detailed update, incorporating recent advances in sedation for gastrointestinal endoscopy.This guideline covers aspects from pre-assessment of the elective 'well' patient to patients with significant comorbidity requiring emergency procedures. Types of sedation are discussed, procedure and room requirements and the recovery period, providing guidance to enhance safety and minimise complications. These guidelines are intended to inform practising clinicians and all staff involved in the delivery of gastrointestinal endoscopy with an expectation that this guideline will be revised in 5-years' time.

Optimal flow of high-flow nasal cannula oxygenation to prevent desaturation during sedation for bronchoscopy: a randomized controlled study

BACKGROUND

Although high-flow nasal cannula (HFNC) oxygenation is currently recommended to prevent desaturation during sedation for bronchoscopy, there is no consensus on an optimal flow rate.

OBJECTIVE

To determine the optimal oxygen flow rate for HFNC to effectively prevent desaturation during sedation for bronchoscopy.

DESIGN

Prospective, randomized, and controlled study.

METHODS

Patients (n = 240) scheduled for bronchoscopy were randomized to receive HFNC with propofol sedation (fraction of inspired oxygen, 100%) at one of six flow rates of 10, 20, 30, 40, 50, and 60 L/min, designated as groups 1-6, respectively.

RESULTS

The incidence of desaturation significantly decreased by increasing the oxygen flow rate (42.5%, 17.5%, 15%, 10%, 2.5%, and 0% for groups 1-6, respectively, p < 0.0001). The optimal oxygen flow rate for HFNC determined by probit regression to effectively prevent desaturation in 95% of patients was 43.20 (95% confidence interval, 36.43-55.96) L/min. The requirement for airway intervention was significantly decreased by increasing the oxygen flow rate.

CONCLUSION

An HFNC flow rate of 50-60 L/min is recommended to prevent desaturation during sedation for bronchoscopy.

REGISTRATION

NCT05298319 at ClinicalTrials.gov.

Machine learning-based risk prediction of hypoxemia for outpatients undergoing sedation colonoscopy: a practical clinical tool

OBJECTIVES

Hypoxemia as a common complication in colonoscopy under sedation and may result in serious consequences. Unfortunately, a hypoxemia prediction model for outpatient colonoscopy has not been developed. Consequently, the objective of our study was to develop a practical and accurate model to predict the risk of hypoxemia in outpatient colonoscopy under sedation.

METHODS

In this study, we included patients who received colonoscopy with anesthesia in Nanjing First Hospital from July to September 2021. Risk factors were selected through the least absolute shrinkage and selection operator (LASSO). Prediction models based on logistic regression (LR), random forest classifier (RFC), extreme gradient boosting (XGBoost), support vector machine (SVM), and stacking classifier (SCLF) model were implemented and assessed by standard metrics such as the area under the receiver operating characteristic curve (AUROC), sensitivity and specificity. Then choose the best model to develop an online tool for clinical use.

RESULTS

We ultimately included 839 patients. After LASSO, body mass index (BMI) (coefficient = 0.36), obstructive sleep apnea-hypopnea syndrome (OSAHS) (coefficient = 1.32), basal oxygen saturation (coefficient = -0.14), and remifentanil dosage (coefficient = 0.04) were independent risk factors for hypoxemia. The XGBoost model with an AUROC of 0.913 showed the best performance among the five models.

CONCLUSION

Our study selected the XGBoost as the first model especially for colonoscopy, with over 95% accuracy and excellent specificity. The XGBoost includes four variables that can be quickly obtained. Moreover, an online prediction practical tool has been provided, which helps screen high-risk outpatients with hypoxemia swiftly and conveniently.

High-Flow Nasal Cannula Therapy as an Adjuvant Therapy for Respiratory Support during Endoscopic Techniques: A Narrative Review

High-flow nasal cannula (HFNC) is a respiratory support technique that delivers a controlled concentration of oxygen with high flow, heat, and humidity via the nasal pathway. As it has many physiological effects, its use has increased for a variety of clinical indications; however, there is limited guidance on using HFNC as a respiratory support tool during endoscopic procedures. We conducted a narrative review to evaluate the effect of HFNC as an adjuvant tool during fiberoptic bronchoscopy (FOB), upper gastrointestinal tract endoscopy, and surgical procedures in adults. A search of the PubMed and Cochrane databases were performed. Approximately 384 publications were retrieved, and 99 were selected (93 original works and 6 case reports with a literature review). In patients who underwent FOB, HFNC appears to be superior to conventional oxygen therapy (COT) in preventing hypoxaemia. In contrast, for gastrointestinal endoscopy, the current evidence is insufficient to recommend HFNC over COT in a cost-effective manner. Finally, in surgical procedures such as laryngeal microsurgery or thoracic surgery, HFNC has been shown to be a safe and effective alternative to orotracheal intubation. As the results are heterogeneous, we advocate for the need for more quality studies to understand the effectiveness of HFNC during endoscopic procedures.

High-Flow Oxygen Therapy in the Perioperative Setting and Procedural Sedation: A Review of Current Evidence

High-flow oxygen therapy (HFOT) is a respiratory support system, through which high flows of humidified and heated gas are delivered to hypoxemic patients. Several mechanisms explain how HFOT improves arterial blood gases and enhances patients' comfort. Some mechanisms are well understood, but others are still unclear and under investigation. HFOT is an interesting oxygen-delivery modality in perioperative medicine that has many clinical applications in the intensive care unit (ICU) and the operating room (OR). The purpose of this article was to review the literature for a comprehensive understanding of HFOT in the perioperative period, as well as its uses in procedural sedation. This review will focus on the HFOT definition, its physiological benefits, and their mechanisms, its clinical uses in anesthesia, and when it is contraindicated.

Modified Manual Chest Compression for Prevention and Treatment of Respiratory Depression in Patients Under Deep Sedation During Upper Gastrointestinal Endoscopy: Two Randomized Controlled Trials

BACKGROUND

We aimed to determine the preventive and therapeutic efficacy of modified manual chest compression (MMCC), a novel noninvasive and device-independent method, in reducing oxygen desaturation events in patients undergoing upper gastrointestinal endoscopy under deep sedation.

METHODS

A total of 584 outpatients who underwent deep sedation during upper gastrointestinal endoscopy were enrolled. In the preventive cohort, 440 patients were randomized to the MMCC group (patients received MMCC when their eyelash reflex disappeared, M1 group) or control group (C1 group). In the therapeutic cohort, 144 patients with oxygen desaturation of a Sp o2 < 95% were randomized to MMCC group (patients who subsequently received MMCC, M2 group) or the conventional treatment group (C2 group). The primary outcomes were the incidence of desaturation episodes with an Sp o2 < 95% for the preventive cohort and the time spent below 95% Sp o2 for the therapeutic cohort. Secondary outcomes included the incidence of gastroscopy withdrawal and diaphragmatic pause.

RESULTS

In the preventive cohort, MMCC reduced the incidence of desaturation episodes <95% (14.4% vs 26.1%; RR, 0.549; 95% confidence interval [CI], 0.37-0.815; P = .002), gastroscopy withdrawal (0% vs 2.29%; P = .008), and diaphragmatic pause at 30 seconds after propofol injection (74.5% vs 88.1%; RR, 0.846; 95% CI, 0.772-0.928; P < .001). In the therapeutic cohort, patients who received MMCC had a significantly shorter time spent below 95% Sp o2 (40 [20-69] seconds vs 91 [33-152] seconds, median difference [95% CI], -39 [-57 to -16] seconds, P < .001), a lower incidence of gastroscopy withdrawal (0% vs 10.4%, P = .018), and more enhanced diaphragmatic movement at 30 seconds after Sp o2 <95% (1.11 [0.93-1.4] cm vs 1.03 [0.7-1.24] cm; median difference [95% confidence interval], 0.16 [0.02-0.32] cm; P = .015).

CONCLUSIONS

MMCC may exert preventive and therapeutic effects against oxygen desaturation events during upper gastrointestinal endoscopy.

Comparison of high-flow nasal cannula and conventional nasal cannula during sedation for endoscopic submucosal dissection: a retrospective study

Background

The high-flow nasal cannula (HFNC) is a relatively recent method that provides high-flow, heated, humidified gas delivery.

Objectives

We compared HFNC (group HF) and conventional nasal cannula (NC) (group CO) during deep sedation with propofol and remifentanil for endoscopic submucosal dissection (ESD).

Design

Single-center, retrospective observational cohort study.

Methods

In this study, a total of 159 cases were analyzed (group CO, 71 and group HF, 88). We collected the data from electronic medical records from September 2020 to June 2021. The lowest oxygen saturation (SpO2), incidence of hypoxia (SpO2 < 90%), rescue interventions, and adverse events between the two groups were investigated.

Results

There were significant differences between the two groups in lowest SpO2 and incidence of hypoxia [group CO versus group HF; 90.3 ± 9.7% versus 95.7 ± 9.0%, 25 (35.2%) versus 10 (11.4%); p < 0.001, p < 0.001; respectively]. Among the rescue interventions, the number of jaw thrust, patient stimulation, O2 flow increase, and nasal airway insertion were significantly higher in the CO group than in the HF group. However, postprocedural chest X-ray showed higher rates of abnormal findings (atelectasis, aspiration, and pneumoperitoneum) in group HF than in group CO [group CO: 8 (11.3%) versus group HF: 26 (29.5%), p = 0.005]. In multivariable analysis, besides group CO, difficult type of lesion was the risk factor for hypoxia.

Conclusions

Compared to the conventional NC, HFNC provided adequate oxygenation and a stable procedure without significant adverse events during sedation for ESD. However, caution is needed to avoid complications associated with deep sedation and difficult type of lesions.

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.

Respiratory support with nasal high flow without supplemental oxygen in patients undergoing endoscopic retrograde cholangiopancreatography under moderate sedation: a prospective, randomized, single-center clinical trial

BACKGROUND

Nasal high flow (NHF) may reduce hypoxia and hypercapnia during an endoscopic retrograde cholangiopancreatography (ERCP) procedure under sedation. The authors tested a hypothesis that NHF with room air during ERCP may prevent intraoperative hypercapnia and hypoxemia.

METHODS

In the prospective, open-label, single-center, clinical trial, 75 patients undergoing ERCP performed with moderate sedation were randomized to receive NHF with room air (40 to 60 L/min, n = 37) or low-flow O₂ via a nasal cannula (1 to 2 L/min, n = 38) during the procedure. Transcutaneous CO₂, peripheral arterial O₂ saturation, a dose of administered sedative and analgesics were measured.

RESULTS

The primary outcome was the incidence of marked hypercapnia during an ERCP procedure under sedation observed in 1 patient (2.7%) in the NHF group and in 7 patients (18.4%) in the LFO group; statistical significance was found in the risk difference (-15.7%, 95% CI -29.1 - -2.4, p = 0.021) but not in the risk ratio (0.15, 95% CI 0.02 - 1.13, p = 0.066). In secondary outcome analysis, the mean time-weighted total PtcCO₂ was 47.2 mmHg in the NHF group and 48.2 mmHg in the LFO group, with no significant difference (-0.97, 95% CI -3.35 - 1.41, p = 0.421). The duration of hypercapnia did not differ markedly between the two groups either [median (range) in the NHF group: 7 (0 - 99); median (range) in the LFO group: 14.5 (0 - 206); p = 0.313] and the occurrence of hypoxemia during an ERCP procedure under sedation was observed in 3 patients (8.1%) in the NHF group and 2 patients (5.3%) in the LFO group, with no significant difference (p = 0.674).

CONCLUSIONS

Respiratory support by NHF with room air did not reduce marked hypercapnia during ERCP under sedation relative to LFO. There was no significant difference in the occurrence of hypoxemia between the groups that may indicate an improvement of gas exchanges by NHF.

TRIAL REGISTRATION

jRCTs072190021 . The full date of first registration on jRCT: August 26, 2019.

Bilevel positive airway pressure for gastroscopy with sedation in patients at risk of hypoxemia: A prospective randomized controlled study

STUDY OBJECTIVE

Hypoxemia is one of the most frequent adverse events during sedated gastroscopy, and there is still no effective means to prevent and cure it. Therefore, we conducted this randomized trial to confirm our hypothesis that, compared with the nasal cannula group, bilevel positive airway pressure (BPAP) would decrease the incidence of hypoxemia in patients with obstructive sleep apnea (OSA) or overweight status undergoing gastroscopy.

DESIGN

In a single-center, prospective, randomized controlled clinical trial, 80 patients aged 18-65 years and with OSA or overweight status who underwent gastroscopy with sedation were randomly assigned to two groups: the nasal cannula and BPAP groups. The primary outcome was the incidence of hypoxemia (75% < peripheral oxygen saturation [SpO2] < 90% for >5 sand <60 s).

MAIN RESULTS

Compared to the nasal cannula group, BPAP therapy significantly decreased the incidence of hypoxemia from 40.0% to 2.5% (absolute risk difference [ARD], 37.5% [95% confidence interval (CI), 21.6 to 53.4], p < 0.001), decreased subclinical respiratory depression from 52.5% to 22.5% (ARD, 30.0% [95% CI, 9.8 to 50.2], p = 0.006), and decreased severe hypoxemia from 17.5% to 0% (ARD, 17.5% [95% CI, 5.7 to 29.3], p = 0.006). The BPAP intervention also decreased the total propofol dosage and operation time and improved anesthesiologist's satisfaction.

CONCLUSION

BPAP therapy significantly decreased the incidence of hypoxemia in patients with OSA or overweight status who underwent gastroscopy.

High-flow nasal oxygen vs. standard oxygen therapy for patients undergoing transcatheter aortic valve replacement with conscious sedation: a randomised controlled trial

BACKGROUND

Minimally invasive surgery is becoming more common and transfemoral transcatheter aortic valve replacement is offered to older patients with multiple comorbidities. Sternotomy is not required but patients must lie flat and still for up to 2-3 h. This procedure is increasingly being performed under conscious sedation with supplementary oxygen, but hypoxia and agitation are commonly observed.

METHODS

In this randomised controlled trial, we hypothesised that high-flow nasal oxygen would provide superior oxygenation as compared with our standard practice, 2 l min^-1 oxygen by dry nasal specs. This was administered using the Optiflow THRIVE Nasal High Flow delivery system (Fisher and Paykel, Auckland, New Zealand) at a flow rate of 50 l min^-1 and FiO₂ 0.3. The primary endpoint was the change in arterial partial pressure of oxygen (pO₂) during the procedure. Secondary outcomes included the incidence of oxygen desaturation, airway interventions, the number of times the patient reached for the oxygen delivery device, incidence of cerebral desaturation, peri-operative oxygen therapy duration, hospital length of stay and patient satisfaction scores.

RESULTS

A total of 72 patients were recruited. There was no difference in change in pO₂ from baseline using high-flow compared with standard oxygen therapy: median [IQR] increase from 12.10 (10.05-15.22 [7.2-29.8]) to 13.69 (10.85-18.38 [8.5-32.3]) kPa vs. decrease from 15.45 (12.17-19.33 [9.2-22.8]) to 14.20 (11.80-19.40 [9.7-35.1]) kPa, respectively. The percentage change in pO2 after 30 min was also not significantly different between the two groups (p = 0.171). There was a lower incidence of oxygen desaturation in the high-flow group (p = 0.027). Patients in the high-flow group assigned a significantly higher comfort score to their treatment (p ≤ 0.001).

CONCLUSION

This study has demonstrated that high flow, compared with standard oxygen therapy, does not improve arterial oxygenation over the course of the procedure. There are suggestions that it may improve the secondary outcomes studied.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number (ISRCTN) 13,804,861. Registered on 15 April 2019. https://doi.org/10.1186/ISRCTN13804861.

Capnographic monitoring reduces hypoxia incidence in older patients undergoing gastrointestinal endoscopy under propofol sedation: study protocol for a multicenter randomized controlled trial

BACKGROUND

Hypoxia is a very common adverse event that occurs during gastrointestinal endoscopy under sedation, especially in older patients, owing to limited reservation of heart, brain, lung, and other organs. Prolonged or severe hypoxia can cause ischemia of the coronary artery and permanent nervous system damage, and even result in death. Hence, it is imperative to reduce or prevent hypoxia during gastrointestinal endoscopy under sedation in older patients. Although several oxygen delivery methods would reduce hypoxia during this procedure, early detection of respiratory depression and early administration of intervention would be the best method to reduce or even confirm the hypoxia. Capnographic monitoring is reportedly more sensitive for detecting respiratory depression before the onset of hypoxia than the current clinical routine monitoring of pulse oxygen saturation; however, its effect is controversial. Therefore, in this study, we aimed to improve the safety of gastrointestinal endoscopy under sedation in older patients.

METHODS

A multicenter, randomized, single-blind, two-arm parallel-group, controlled with an active comparator, interventional superiority clinical trial will be conducted to evaluate the impact of an additional capnographic monitoring-based intervention on the incidence of hypoxia in older patients. Patients (n = 1800) scheduled for gastrointestinal endoscopy with propofol sedation will be randomly assigned to either a control or interventional arm, wherein standard or capnographic monitoring is implemented, respectively.

DISCUSSION

This study primarily aims to examine whether an additional capnographic monitoring-based intervention can reduce the incidence of hypoxia in older patients during gastrointestinal endoscopy under propofol and sufentanil sedation. The results of this study may extensively impact gastrointestinal endoscopy under sedation and the development of associated guidelines.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05030870. Registered on September 1, 2021.

Utility of high-flow nasal oxygen in comparison to conventional oxygen therapy during upper gastrointestinal endoscopic procedures under sedation: A systematic review and meta-analyses

BACKGROUND

Sedation and analgesia are the integral components of modern-day upper gastrointestinal (GI) endoscopic procedures. Irrespective of the sedative agent, hypoxia is the most commonly encountered unwarranted event with sedation. The current study intends to scrutinize whether high-flow nasal oxygen (HFNO) is advantageous for providing respiratory support during upper GI endoscopic procedures over other conventional low-flow oxygen delivery modalities, e.g. nasal cannula, facemask, etc. METHODS: An extensive screening of electronic databases was done till July 31, 2022, after enlisting in International prospective register of systematic reviews (PROSPERO) (CRD42021245409). Randomized controlled trials (RCT), comparative cohort studies, case series, cross-sectional studies and case-control studies evaluating the utility of HFNO during upper GI endoscopy under sedation were included in this meta-analysis.

RESULTS

We retrieved eight randomized control studies and one longitudinal study with 3294 patients. The application of HFNO during endoscopy led to lesser incidence of desaturation spells (odds ratio [OR] = 0.23; 95% CI 0.11-0.48; I² = 71%), reduced procedural interruption (OR = 0.11; 95% CI 0.02-0.60; I² = 88%), better nadir SpO² level during procedure (mean difference [MD] = 3.16; 95% CI 0.54-5.78; I² = 73%), overall lesser incidence of sedation-related adverse events (OR = 0.63; 95% CI 0.42-0.93; I² = 25%), with no significant impact on the duration of endoscopy (MD = 0.15; 95% CI - 0.02 to 0.31, I² = 0%).

CONCLUSION

HFNO is a novel option for upper GI endoscopy under sedation.

CLINICAL TRIAL NUMBER AND REGISTRY URL

CRD42021245409 ( https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021245409 ).

Comparison of high-flow nasal cannula and conventional oxygen therapy for high-risk patients during bronchoscopy examination: protocol for a randomized controlled trial

INTRODUCTION

High-flow nasal cannula (HFNC) has been proven to improve oxygenation and avoid intubation in hypoxemic patients. It has also been utilized during endoscopy examination to reduce the incidence of hypoxia. However, little is known about the effects of HFNC versus conventional oxygen therapy (COT) on oxygenation during bronchoscopy examination via nasal route; particularly, no study has compared the use of HFNC with that of COT at similar F_IO₂ for patients who have high-risk factors of desaturation during bronchoscopy examination.

METHODS AND ANALYSIS

This randomized controlled trial will be implemented in four academic centers in China. Patients who have high-risk factors including hypoxemia, hypercapnia, morbid obesity, and narrow airway will be enrolled to use HFNC or COT during bronchoscopy examination. In the HFNC group, the initial gas flow will be set at 50 L/min with a fraction of inspired oxygen (F_IO₂) at 0.45, if the patient tolerates, the flow can be increased to 60L/min at most, while in the COT group, oxygen flow will be set at 6 L/min via a conventional nasal cannula. After 5 min pre-oxygenation, the bronchoscope will be inserted via the nasal route. Vital signs, oxygenation (SpO₂), and transcutaneous CO₂ (PtCO₂) will be continuously monitored. The primary outcome is the incidence of hypoxemia, defined as SpO₂ < 90% for 10 s during bronchoscopy examination, and secondary outcomes include the need for treatment escalation and adverse events.

DISCUSSION

Hypoxia is a common complication of bronchoscopy, our study attempted to demonstrate that HFNC may reduce the probability of hypoxia during bronchoscopy in high-risk patients. The results will be disseminated through peer-reviewed journals and national and international conferences.

TRIAL REGISTRATION

http://www.chictr.org.cn/ : ChiCTR2100055038. Registered on 31 December 2021.

Effect of high-flow nasal oxygen on hypoxaemia during procedural sedation: a systematic review and meta-analysis

We conducted a systematic review to evaluate the effect of high-flow nasal oxygen and conventional oxygen therapy during procedural sedation amongst adults and children. We searched MEDLINE, EMBASE and CINAHL for randomised controlled trials that reported the effects of high-flow nasal oxygen during procedural sedation. The primary outcome measure was hypoxaemia and the secondary outcomes were minimum oxygen saturation; hypercarbia; requirement for airway manoeuvres; and procedure interruptions. The quality of evidence was assessed using the revised Cochrane risk-of bias tool and grading of recommendations, assessment, development and evaluation (GRADE). Nineteen randomised controlled trials (4121 patients) including three in children were included. Administration of high-flow nasal oxygen reduced hypoxaemia, risk ratio (95%CI) 0.37 (0.24-0.56), p < 0.001; minor airway manoeuvre requirements, risk ratio (95%CI) 0.26 (0.11-0.59), p < 0.001; procedural interruptions, risk ratio (95%CI) 0.17 (0.05-0.53), p = 0.002; and increased minimum oxygen saturation, mean difference (95%CI) 4.1 (2.70-5.50), p < 0.001; as compared with the control group. High-flow nasal oxygen had no impact on hypercarbia, risk ratio (95%CI) 1.24 (0.97-1.58), p = 0.09, I²  = 0%. High-flow nasal oxygen reduced the incidence of hypoxaemia regardless of the procedure involved, degree of fractional inspired oxygen, risk-profile of patients and mode of propofol administration. The evidence was ascertained as moderate for all outcomes except for procedure interruptions. In summary, high-flow nasal oxygen compared with conventional oxygenation techniques reduced the risk of hypoxaemia, increased minimum oxygen saturation and reduced the requirement for airway manoeuvres. High-flow nasal oxygen should be considered in patients at risk of hypoxaemia during procedural sedation.

Evaluation of the sedative effect of sublingual lorazepam versus placebo in patients underwent endoscopy: a double-blind, randomized controlled clinical trial

Background

Digestive endoscopy (DE) is uncomfortable for most patients. Lorazepam is a potent benzodiazepine with anxiolytic and sedative effects.

Objective

This study aims to determine the sedative effect of sublingual lorazepam versus placebo as a premedication in patients who underwent DE.

Design

This is a mono-center, double-blind, and randomized controlled trial.

Methods

A lorazepam sublingual tablet was made by researchers and physical tests were done on it, then the double-blind placebo-controlled trial was done to investigate the efficacy of 2 mg sublingually administered lorazepam as a premedication for endoscopy. Lorazepam or a placebo tablet was administered sublingually 30 min before the endoscopy. The patients, nurses, and physicians were blinded to the patient group. The depth of sedation was evaluated according to the American Society of Anesthesiology.

Results

In all, 116 patients were randomly assigned to take either lorazepam (n = 58) or a placebo (n = 58). The results of physical properties tests were acceptable according to United States Pharmacopeia. There were no statistical differences between groups regarding age and gender. In the lorazepam group, 75.8% of patients showed mild sedation, and 24.2% of patients showed no sedation. All of the patients in the placebo had no sedation (p = 0.001). Time of procedure (p < 0.001), intraoperative O2 saturation (p < 0.001), intraoperative heart rate (p < 0.001), and intraoperative blood pressure (p < 0.001) were significantly lower in the lorazepam group. No significant or dangerous side effects were observed except a bit of giddiness and dizziness.

Conclusion

The results of this study showed that prescription of sublingual lorazepam 25-30 min before endoscopy provided mild sedation.

Registration

IRCT201611039014N130 (05/11/2016); https://en.irct.ir/trial/9568.

[The role of HFNC oxygen in pre-oxygenation prior to intubation and the practice of invasive procedures]

Over recent years, High Flow Nasal Cannula (HFNC) oxygen therapy has been more and more extensively applied in numerous medical settings, and it is now carried out in invasive procedures such as pre-oxygenation before orotracheal intubation, often leading to complications. More generally, pre-oxygenation is aimed at maintaining the highest possible oxygen saturation for extended periods of time. With this in mind, HFNC seems as effective as standard oxygen delivery with regard to hematosis in patients with mild or moderate hypoxemia, and it presents the advantage of reducing the adverse events associated with intubation. That said, during pre-oxygenation of patients with severe hypoxemia, non-invasive ventilation (NIV) is probably more effective than HFNC, especially in the prevention of respiratory events. However, in patients with little or no hypoxemia undergoing risky procedures such as bronchial endoscopy, HFNC allows better oxygen saturation than standard methods. To summarize, even though NIV remains useful in unstable patients, especially in decreasing desaturation episodes, HFNC could represent a reasonable alternative in case of poor tolerance, allowing continuous oxygenation of patients requiring digestive endoscopy or trans-esophageal ultrasound.

High-flow oxygen via oxygenating mouthguard in short upper gastrointestinal endoscopy: A randomised controlled trial

BACKGROUND

Anaesthetic care during upper gastrointestinal (GI) endoscopy has the unique challenge of maintaining ventilation and oxygenation via a shared upper airway. Supplemental oxygen is recommended by international society guidelines, however, the optimal route or rate of oxygen delivery is not known. Various oxygen delivery devices have been investigated to improve oxygenation during upper GI endoscopy, however, these are limited by commercial availability, costs and in some cases, the expertise required for insertion. Anecdotally at our centre, higher flows of supplemental oxygen can safely be delivered via an oxygenating mouthguard routinely used during upper GI endoscopic procedures.

AIM

To assess the incidence of hypoxaemia (SpO₂ < 90%) in patients undergoing upper GI endoscopy receiving supplemental oxygen using an oxygenating mouthguard at 20 L/min flow compared to standard nasal cannula (SNC) at 2 L/min flow.

METHODS

A single centre, prospective, randomised clinical trial at two sites of an Australian tertiary hospital between October 2020 and September 2021 was conducted. Patients undergoing elective upper gastrointestinal endoscopy under deep sedation were randomised to receive supplemental oxygen via high-flow via oxygenating mouthguard (HFMG) at 20 L/min flow or SNC at 2 L/min flow. The primary outcome was the incidence of hypoxaemia of any duration measured by pulse oximetry. Intraprocedural-related, procedural-related, and sedation-related adverse events and patient-reported outcomes were also recorded.

RESULTS

Three hundred patients were randomised. Eight patients were excluded after randomisation. 292 patients were included in the intention-to-treat analysis. The incidence of hypoxaemia was significantly reduced in those allocated HFMG. Six patients (4.4%) allocated to HFMG experienced an episode of hypoxaemia, compared to thirty-four (22.1%) patients allocated to SNC (P value < 0.001). No significant difference was observed in the rates of adverse events or patient-reported outcome measures.

CONCLUSION

The use of HFMG offers a novel approach to reducing the incidence of hypoxaemia during short upper gastrointestinal endoscopic procedures in low-risk patients undergoing deep sedation.

High-flow nasal oxygenation during gastrointestinal endoscopy. Systematic review and meta-analysis

Background

The use of high-flow nasal oxygen (HFNO) has the potential to improve patient safety by limiting hypoxaemia during gastrointestinal endoscopy. The degree of benefit is not adequately established.

Methods

English language literature searches of PubMed, Scopus, Web of Science, and Cochrane Library electronic databases were performed to identify randomised controlled trials comparing HFNO and conventional oxygen therapy (COT) for patients undergoing gastrointestinal endoscopy under deep sedation. The primary endpoint was the incidence of hypoxic events observed during endoscopic procedures. The secondary endpoints were the incidence of recourse to rescue manoeuvres, procedure interruption, and adverse events. A meta-analysis and a post hoc trial sequence analysis were performed.

Results

A total of 2867 patients from six randomised controlled trials were considered. Desaturation was observed in 5.2% and 27.2% of patients receiving HFNO and COT, respectively. Desaturation <90% was observed in 1.8% and 12.6% of the patients receiving HFNO and COT, respectively. In the subgroup analysis, desaturation occurrence was lower during HFNO than during COT in non-obese patients (2.2% vs 25.2%) and obese patients (22.9% vs 43.3%). Desaturation occurrence was lower during maximum (3.6% vs 26.9%) and minimum (15.9% vs 29.8%) HFNO therapy than during COT. HFNO showed a lower recurrence to rescue manoeuvres rate (4.7% vs 34.3%), a lower procedure interruption rate (0.4% vs 6.7%), and a lower adverse events rate (18.7% vs 21%) than COT. A high level of heterogeneity between the studies precluded confidence in drawing inference from the meta-analysis.

Conclusions

The evidence reviewed suggests that compared with COT, HFNO has fewer hypoxaemic events during gastrointestinal endoscopy, but this may not apply to all patients and clinical scenarios.

The effect of varying inhaled oxygen concentrations of high-flow nasal cannula oxygen therapy during gastroscopy with propofol sedation in elderly patients: a randomized controlled study

BACKGROUND

Despite evidence that high-flow nasal cannula oxygen therapy (HFNC) promotes oxygenation, its application in sedated gastroscopy in elderly patients has received little attention. This study investigated the effect of different inhaled oxygen concentrations (FiO₂) of HFNC during sedated gastroscopy in elderly patients.

METHODS

In a prospective randomized single-blinded study, 369 outpatients undergoing regular gastroscopy with propofol sedation delivered by an anesthesiologist were randomly divided into three groups (n = 123): nasal cannula oxygen group (Group C), 100% FiO₂ of HFNC group (Group H100), and 50% FiO₂ of HFNC (Group H50). The primary endpoint in this study was the incidence of hypoxia events with pulse oxygen saturation (SpO₂) ≤ 92%. The secondary endpoints included the incidence of other varying degrees of hypoxia and adverse events associated with ventilation and hypoxia.

RESULTS

The incidence of hypoxia, paradoxical response, choking, jaw lift, and mask ventilation was lower in both Group H100 and Group H50 than in Group C (P < 0.05). Compared with Group H100, Group H50 showed no significant differences in the incidence of hypoxia, jaw lift and mask ventilation, paradoxical response, or choking (P > 0.05). No patients were mechanically ventilated with endotracheal intubation or found to have complications from HFNC.

CONCLUSION

HFNC prevented hypoxia during gastroscopy with propofol in elderly patients, and there was no significant difference in the incidence of hypoxia when FiO₂ was 50% or 100%.

TRIAL REGISTRATION

This single-blind, prospective, randomized controlled trial was approved by the Ethics Committee of Nanjing First Hospital (KY20201102-04) and registered in the China Clinical Trial Center (20/10/2021, ChiCTR2100052144) before patients enrollment. All patients signed an informed consent form.

Incidence of oxygen desaturation using a high-flow nasal cannula versus a facemask during flexible bronchoscopy in patients at risk of hypoxemia: a randomised controlled trial

BACKGROUND

Patients with obstructive sleep apnoea (OSA), male sex, obesity, older age or hypertension are prone to hypoxemia during flexible bronchoscopy. This study investigated whether using a high-flow nasal cannula (HFNC) could reduce the incidence of oxygen desaturation during bronchoscopy under deep sedation in patients at risk of hypoxemia.

METHODS

A total of 176 patients at risk of hypoxemia who underwent flexible bronchoscopy under deep sedation were randomly assigned to two groups: the HFNC group (humidified oxygen was supplied via a high-flow nasal cannula at a rate of 60 L/min and a concentration of 100%, n = 87) and the facemask group (oxygen was supplied via a tight-fitting facemask at a rate of 6 L/min and a concentration of 100%, n = 89).

RESULTS

Oxygen desaturation occurred in 4 (4.6%) patients in the HFNC group and 26 (29.2%) patients in the facemask group (P < 0.001). The facemask group required more jaw thrust manoeuvres than the HFNC group (43[48.3%] vs. 5[5.7%], P < 0.001). 8 patients (9.0%) in the facemask group and none in the HFNC group required bag-mask ventilation (P = 0.012).

CONCLUSION

The use of an HFNC can reduce the incidence of oxygen desaturation and the requirement for airway intervention in patients at risk of hypoxemia during flexible bronchoscopy under deep sedation.

TRIAL REGISTRATION

www.chiCTR.org.cn Identifier: ChiCTR2100044105. Registered 11/03/2021.

Recent advances in the use of high flow nasal oxygen therapies

High flow nasal oxygen is a relatively new option for treating patients with respiratory failure, which decreases work of breathing, improves tidal volume, and modestly increases positive end expiratory pressure. Despite well-described physiologic benefits, the clinical impact of high flow nasal oxygen is still under investigation. In this article, we review the most recent findings on the clinical efficacy of high flow nasal oxygen in Type I, II, III, and IV respiratory failure within adult and pediatric patients. Additionally, we discuss studies across clinical settings, including emergency departments, intensive care units, outpatient, and procedural settings.

Effects of intravenous lidocaine on hypoxemia induced by propofol-based sedation for gastrointestinal endoscopy procedures: study protocol for a prospective, randomized, controlled trial

Background

Oxygen-desaturation episodes, blood pressure drops, and involuntary body movement are common problems that occur in propofol-based sedation in the procedure of painless gastrointestinal (GI) endoscopy. As a widely used analgesic adjuvant, intravenous lidocaine can reduce the consumption of propofol during ERCP or colonoscopy. However, it is still unknown how lidocaine affects the incidence of oxygen-desaturation episodes and cardiovascular events, and involuntary movement during painless GI endoscopy. Therefore, we aimed to assess the effectiveness and safety of intravenous lidocaine in propofol-based sedation for GI endoscopy.

Methods

We will conduct a single-center, prospective, randomized, double-blind, saline-controlled trial. A total number of 300 patients undergoing painless GI procedures will be enrolled and randomly divided into the lidocaine group (Group L) and the control group (Group C). After midazolam and sufentanil intravenous injection, a bolus of 1.5 mg/kg lidocaine was immediately injected and followed by a continuous infusion of 4 mg/kg/h in the lidocaine group, whereas the same volumes of saline solution in the control group. Then, propofol was titrated to produce unconsciousness during the procedure. The primary outcome will be the incidence of oxygen-desaturation episodes. Secondary outcomes will be the incidence of involuntary body movement, discomfort symptoms, propofol consumption, endoscopist, and patient satisfaction.

Discussion

Propofol-based deep sedation without intubation is widely used in painless GI endoscopy. However, adverse events such as hypoxemia often occur clinically. We expect to assess the effect of lidocaine on reducing the incidence of oxygen-desaturation episodes, cardiovascular events, and involuntary body movement. We believe that the results of this trial will provide an effective and safe method for painless GI endoscopy.

Trial registration

Chinese Clinical Trial Registry ChiCTR2100053818. Registered on 30 November 2021.

The median effective doses of propofol combined with two different doses of nalbuphine for adult patients during painless gastroscopy

Objective: Propofol is the most widely administered intravenous anesthetic to induce deep sedation for gastroscopy procedures. Coadministration of nalbuphine can provide analgesia and sedation to patients experiencing visceral pain, thereby decreasing the amount of propofol needed and reducing the risk of propofol-induced adverse events. We carried out this study to determine the median effective dose (ED50) of propofol in combination with different dosages of nalbuphine and the optimal dosage of nalbuphine during painless gastroscopy.

Methods: We recruited sixty-five patients aged 18–60 years who underwent elective painless gastroscopy. A total of sixty-one patients were allocated randomly to the N1 group (nalbuphine 0.1 mg/kg) or N2 group (nalbuphine 0.15 mg/kg). Three minutes after administration of nalbuphine, patients received a preset dose of propofol at 2.0 mg/kg with a dose gradient of 0.2 mg/kg according to Dixon’s “up-and-down” method. The primary outcome was the ED50 of propofol in combination with nalbuphine. Hemodynamic parameters, recovery time, pain score, and adverse events were recorded as secondary outcomes.

Results: The ED50 of propofol in the N2 group was significantly lower than that observed in the N1 group (p < 0.01). Using probit analysis, the ED50 and ED95 of propofol were 1.632 mg/kg and 2.759 mg/kg in the N1 group and 1.111 mg/kg and 2.243 mg/kg in the N2 group, respectively. The incidence of hypotension in the N2 group was lower than that in the N1 group (p < 0.05), and the recovery time was shorter than that of the N1 group (p < 0.05).

Conclusion: In adult patients, 0.15 mg/kg nalbuphine led to a significant reduction in the ED50 and ED95 of propofol during gastroscopy. This dose of nalbuphine also reduced the incidence of hypotension and shortened the recovery time. Therefore, nalbuphine (0.15 mg/kg) combined with propofol is a safe option for enhancing recovery after painless gastroscopy in adult patients.

Clinical Trial Registration: [https://www.chictr.org.cn/edit.aspx?pid=126699&htm=4], identifier [ChiCTR2100053204].

High flow nasal oxygen versus conventional oxygen therapy in gastrointestinal endoscopy with conscious sedation: Systematic review and meta-analysis with trial sequential analysis

OBJECTIVES

Although conventional oxygen therapy (COT) is widely used, hypoxemia frequently occurs in gastrointestinal endoscopy with conscious sedation and can lead to life-threatening consequences. High flow nasal oxygen (HFNO) has been applied to improve oxygenation in clinical entities. However, its efficacy to prevent hypoxemia in gastrointestinal endoscopy with conscious sedation has not been evaluated.

METHODS

We searched databases to identify randomized controlled trials that compared the efficacy of HFNO with COT in gastrointestinal endoscopy with conscious sedation. The primary outcome was hypoxemia. Meta-analyses with trial sequential analysis were performed using a random-effects model.

RESULTS

Eight trials with 3212 patients were included. Compared with COT, HFNO significantly reduced the risk of hypoxemia (eight trials; 3212 patients; risk ratio 0.30; 95% confidence interval [CI] 0.13-0.70). Trial sequential analysis showed that the cumulative Z curve did not cross the monitoring or futility boundaries, nor reach the required information size line, indicating that more trials are needed to reach a definitive conclusion. Subgroup analyses indicated the superiority of HFNO over COT with respect to hypoxemia in patients at low risk and high risk. HFNO further improved the lowest oxygen saturation (four trials; 459 patients; mean difference 2.30, 95% CI 0.84-3.77).

CONCLUSIONS

Compared with COT, HFNO can reduce the risk of hypoxemia and improve the lowest oxygen saturation in gastrointestinal endoscopy with conscious sedation. However, the results should be interpreted with caution due to substantial heterogeneity and limited evidence. Further studies are needed to verify the preliminary findings.

High flow nasal cannula for patients undergoing bronchoscopy and gastrointestinal endoscopy: A systematic review and meta-analysis

Background

High flow nasal cannula is gaining increasingly used in patients undergoing endoscopic procedures. We undertook this systematic review and meta-analysis to determine whether high flow nasal cannula (HFNC) could effectively minimize the risk of hypoxemia as compared with conventional oxygen therapy (COT).

Methods

We performed a comprehensive search of Pubmed, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and Web of Science. Studies involving the application of HFNC during endoscopic procedures were identified.

Results

We included 15 randomized controlled trials (7 bronchoscopy, 8 gastrointestinal endoscopy). Patients receiving HFNC during endoscopic procedures had a significantly lower risk of hypoxemia (defined as SpO2 &lt; 90%) versus COT group (risk ratio = 0.32; 95%CI (0.22–0.47), 13 studies, 4,093 patients, moderate-quality evidence, I2 = 48.82%, P &lt; 0.001). The lowest SpO2 was significantly higher in HFNC group (mean difference = 4.41; 95%CI (2.95–5.86), 9 studies, 1,449 patients, moderate-quality evidence, I2 = 81.17%, P &lt; 0.001) than those receiving COT. No significant difference was detected between groups in end-procedure partial pressure of CO2 (standard mean difference  =  −0.18; 95%CI (−0.52–0.15), 5 studies, 238 patients, moderate-quality evidence, I2 = 42.25%, P = 0.29). Patients receiving HFNC were associated a lower need for airway intervention (risk ratio = 0.45; 95%CI (0.24–0.84), 8 studies, 2,872 patients, moderate-quality evidence, I2 = 85.97%, P = 0.01) and less procedure interruption (risk ratio = 0.36; 95%CI (0.26–0.51), 6 studies, 1,562 patients, moderate-quality evidence, I2 = 0.00%, P &lt; 0.001). The overall intubation rate after endoscopy was 0.20% in both group, with no difference detected (risk ratio = 1.00; 95%CI (0.30–3.35), 7 studies, 2,943 patients, low-quality evidence, I2 = 0.00%, P = 1.00).

Conclusion

This systematic review and meta-analysis found moderate to low evidence that the application of HFNC was associated with improved oxygenation, decreased need for airway intervention, and reduced procedure interruption in patients undergoing endoscopic procedures. Future larger sample and high-quality studies are warranted to confirm our result and further investigate the effectiveness of HFNC in patients at risk.

Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier: CRD42022298032.

High-flow nasal oxygen reduces the incidence of hypoxia in sedated hysteroscopy for assisted reproduction

Backgrounds and aims

Pain is the main reason for hysteroscopy failure. In day-surgical settings, hysteroscopy procedures are commonly performed with the patient under sedation. Hypoxia is the most common adverse event during sedation and can lead to severe adverse events. This study aimed to compare the incidence of hypoxia when using high-flow nasal oxygen (HFNO) with that when using regular nasal oxygen in patients undergoing hysteroscopy with sedation.

Materials and methods

In this single-center, prospective, randomized, single-blinded study, 960 female patients undergoing elective diagnostic or operative hysteroscopy were randomly enrolled into the following two groups: the regular nasal group [O₂ (3–6 L/min) covered by an HFNO] and the HFNO group [O₂ (30–60 L/min)] from September 2021 to December 2021. All women were sedated with propofol (1.5 mg/kg) and remifentanil (1.5 μg/kg) in the operating room. The primary outcome was the incidence of hypoxia (75% ≤ SpO₂ < 90%, < 60 s).

Results

HFNO decreased the incidence of hypoxia (75% ≤ SpO₂ < 90%, < 60 s), subclinical respiratory depression (90% ≤ SpO₂ < 95%) and severe hypoxia (SpO₂ < 75% for any duration or 75% ≤ SpO₂ < 90% for ≥ 60 s) from 24.38 to 0.83%, from 11.25 to 1.46% and from 3.75 to 0%, respectively (P < 0.001).

Conclusion

In procedures conducted to treat female infertility, HFNO can reduce hypoxia during hysteroscopy in patients sedated with propofol, and it can prevent the occurrence of subclinical respiratory depression and severe hypoxia.

Impact of High-Flow Nasal Cannula Oxygenation on the Prevention of Hypoxia During Endoscopic Retrograde Cholangiopancreatography in Elderly Patients: A Randomized Clinical Trial

BACKGROUND

Hypoxia is the most frequently occurring adverse effect during endoscopic retrograde cholangiopancreatography (ERCP) under sedation; thus, oxygen must be properly supplied to prevent a reduction of oxygen saturation. In this study, we intend to verify the preventive effect for hypoxia during ERCP, using a high-flow nasal cannula (HFNC), in elderly patients.

METHODS

As a multicenter prospective randomized trial, patients who underwent ERCP with propofol-based sedation were randomly assigned into two groups: Patients in the HFNC group were supplied with oxygen via an HFNC, and those in the standard nasal cannula group were supplied with oxygen via a low-flow nasal cannula. The co-primary end points were the lowest oxygen saturation rate and hypoxia during the overall procedure.

RESULTS

A total of 187 patients (HFNC group: 95; standard nasal cannula group: 92) were included in the analysis. Unexpected hypoxia events were more frequently observed among patients in the standard nasal cannula group than among patients in the HFNC group (13% vs. 4%, odds ratio 3.41, 95% confidence interval 1.06-11.00, p = 0.031). The mean of the lowest oxygen saturation rate during ERCP was significantly lower in the standard nasal cannula group than in the HFNC group (95% vs. 97%, p = 0.002).

CONCLUSION

Oxygen supplementation with an HFNC can prevent oxygen desaturation and hypoxia events in patients undergoing ERCP under sedation. Trial registration Clinical Research Information Service (CRIS; KCT0004960).

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.

Long-term high-risk drinking does not change effective doses of propofol for successful insertion of gastroscope in Chinese male patients

Background

Available literature indicates that long-term drinkers demand a higher dose of propofol for induction of anesthesia than non-drinkers. However, there is no study having assessed the influence of long-term high-risk drinking (LTHRD) on the effective doses of propofol for successful insertion of gastroscope with sedation. This study was designed to compare the effective doses of propofol for successful insertion of gastroscope between LTHRD and non-drinking (ND) Chinese male patients.

Methods

Thirty-one LTHRD patients and 29 ND male patients undergoing elective gastroscopy with propofol sedation were enrolled. The modified Dixon’s up-and-down method was applied to determine the calculated median effective dose (ED₅₀) of propofol for successful insertion of gastroscope. Furthermore, the isotonic regression analysis was used to establish the dose–response curve of propofol and assess the effective doses of propofol where 50% (ED₅₀) and 95% (ED₉₅) of gastroscope insertions were successful.

Results

The calculated ED₅₀ of propofol for successful insertion of gastroscope was 1.55 ± 0.10 mg/kg and 1.44 ± 0.11 mg/kg in the LTHRD and ND patients. The isotonic regression analysis further showed that ED₅₀ and ED₉₅ of propofol for successful insertion of gastroscope was 1.50 mg/kg (95%CI, 1.40–1.63) and 1.80 mg/kg (95%CI, 1.74–1.90) in the LTHRD patients, respectively; 1.40 mg/kg (95% CI, 1.27–1.57) and 1.60 mg/kg (95%CI, 1.56–1.65) in the ND patients. The ED₅₀ of propofol for successful insertion of gastroscope was not significantly different between LTHRD and ND patients.

Conclusions

This study demonstrates that the difference in the estimated ED₅₀ of propofol for successful insertion of gastroscope between LTHRD and ND Chinese male patients was not statistically significant.

Trial registration

The study was registered on November 28, 2020 (ChiCTR2000040382) in the Chinese Clinical Trial Registry.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01725-2.

The effectiveness of high-flow nasal cannula during sedated digestive endoscopy: a systematic review and meta-analysis

BACKGROUND

Studies evaluating the role of high-flow nasal cannula (HFNC) in sedated digestive endoscopy have reported conflicting results. This meta-analysis evaluates the effectiveness of HFNC in patients undergoing digestive endoscopy procedures under sedation.

METHODS

PubMed, Medline, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science, were searched from inception to 31 July 2021. Only randomized clinical trials comparing HFNC with standard nasal cannula oxygen (SNC) during sedated digestive endoscopy were included. The incidence of hypoxemia was the primary outcome, and the secondary outcome was the percentage of patients who needed airway interventions.

RESULTS

Seven studies that enrolled 2998 patients were included. When compared to SNC, HFNC was associated with a significant reduction in hypoxemia incidence (OR 0.24, 95% CI 0.09 to 0.64) and airway intervention requirements (OR 0.15, 95% CI 0.03 to 0.69), with both high heterogeneity (I² = 81% and 94%). In subgroup analysis, when hypoxemia was defined as pulse oxygen saturation (SpO₂) < 90%, low risk of hypoxemia subjects who received HFNC were associated with a significant reduction in hypoxemia incidence (OR 0.02, 95% CI 0.00 to 0.07; heterogeneity I² = 39%) and airway intervention requirements (OR 0.02, 95% CI 0.01 to 0.04; heterogeneity I² = 15%). However, in the high risk of hypoxemia subjects, there were no significant differences between the two oxygen administration techniques in both primary (OR 0.81, 95% CI 0.36 to 1.78; heterogeneity I² = 0%) and secondary outcomes (OR 0.85, 95% CI 0.46 to 1.59; heterogeneity I² = 0%).

CONCLUSIONS

Compared to SNC, HFNC not only reduce the incidence of hypoxemia but also reduce the requirements for airway interventions during sedated digestive endoscopy procedures, especially in patients at low risk for hypoxemia. In high risk of hypoxemia patients, there were no significant differences between the two oxygen administration techniques. Trial registration PROSPERO International prospective register of systematic reviews on 28 July 2021, registration no. CRD42021264556.

High-flow versus conventional nasal cannula oxygen supplementation therapy and risk of hypoxia in gastrointestinal endoscopies: Α systematic review and meta-analysis

BACKGROUND AND AIMS

Gastrointestinal endoscopy (GIE) represents a mainstay diagnostic and therapeutic procedure in modern clinical practice. Hypoxemia and respiratory failure during endoscopy constitute major complications and concerns for endoscopists. Emerging evidence supports the utilization of high-flow nasal cannula (HFNC) over conventional nasal cannula (CNC) for oxygen supplementation and avoidance of hypoxemia. Aim of our study was to compare the risk of hypoxemia in patients undergoing GIE with HFNC versus CNC oxygen supplementation recruited by randomized controlled trials (RCTs).

METHODS

We conducted an electronic literature search in established medical databases i.e. PubMed, EMBASE and Cochrane to identify RCTs investigating the abovementioned association. The enrolled studies were evaluated for risk of bias and inserted into a random effects model for meta-analysis; sub-group analyses and publication bias were also assessed.

RESULTS

Out of 271 initially retrieved articles, five RCTs were eligible for meta-analysis with totally 2656 recruited patients (1299 HFNC and 1357 CNC). A statistically significant reduced relative risk (RR) of hypoxemia among HFNC patients was revealed (RR=0.18, CI95%: 0.05-0.61), whilst with high heterogeneity (I²:79.94%, p<0.01). Patients undergoing upper GIE with HFNC displayed a significantly lower risk of hypoxemia (96%, p<0.001, I²:15.59%), even after exclusion of endoscopic retrograde cholangiopancreatography (ERCP) cases (RR:0.03, CI95%: 0.01-0.21), albeit with higher heterogeneity (I²:41.82%). Contrariwise, colonoscopy with HFNC did not yield a statistically significant RR reduction (p=0.14).

CONCLUSION

Patients undergoing upper GIE with HFNC oxygen experience significantly less hypoxemia burden than CNC counterparts. Further research is warranted to establish this emerging association to target optimal safety during endoscopy.

Endo-anesthesia: a primer

Gastrointestinal (GI) endoscopy has witnessed a Cambrian explosion of techniques, indications, and expanding target populations. GI endoscopy encompasses traditional domains that include preventive measures, palliation, as alternative therapies in patients with prohibitive risks of more invasive procedures, and indicated primary treatments. But, it has expanded to include therapeutic and diagnostic interventional endosonography, luminal endoscopic resection, third space endotherapy, endohepatology, and endobariatrics. The lines between surgery and endoscopy are blurred on many occasions within this paradigm. Moreover, patients with high degrees of co-morbidity and complex physiology require more nuanced peri-endoscopic management. The rising demand for endoscopy services has resulted in the development of endoscopy referral centers that offer these invasive procedures as directly booked referrals for regional and rural patients. This further necessitates specialized programs to ensure appropriate evaluation, risk stratification, and optimization for safe sedation and general anesthesia if needed. This landscape is conducive to the organic evolution of endo-anesthesia to meet the needs of these focused and evolving practices. In this primer, we delineate important aspects of endo-anesthesia care and provide relevant clinical and logistical considerations pertaining to the breadth of procedures.

A Bibliometric Analysis of Endoscopic Sedation Research: 2001-2020

Background and Aims: To evaluate endoscopic sedation research and predict research hot spots both quantitatively and qualitatively using bibliometric analysis. Methods: We extracted relevant publications from the Web of Science Core Collection (WoSCC) on 13 December 2020. We examined the retrieved data by bibliometric analysis (e.g., co-cited and cluster analysis, keyword co-occurrence) using the software CiteSpace and VOSviewer and the website of bibliometrics, the Online Analysis Platform of Literature Metrology (http://bibliometric.com/), to analyse and predict the trends and hot spots in this field. Main Results: We identified 2,879 articles and reviews on endoscopic sedation published between 2001 and 2020. Although the overall trend is increasing, with slight fluctuation in some years, there were significant increases in 2007 and 2012. In respect of the contributions on endoscopic sedation research, the United States (US) had the greatest number of publications, and it was followed by Japan and China. In addition, collaboration network analysis revealed that the most frequent collaboration was between the US and China. Six of the top ten most prolific research institutions were located in the US. The most publications on endoscopic sedation research in the past two decades were found primarily in journals on gastroenterology and hepatology. Keyword co-occurrence and co-citation cluster analysis revealed the most popular terms relating to endoscopic sedation in the manner of cluster labels; these included patient anxiety, tolerance, ketamine, propofol, hypoxia, nursing shortage, endoscopic ultrasonography, colorectal cancer, carbon dioxide insufflation, and water exchange (WE). Keyword burst detection suggested that propofol sedation, adverse event, adenoma detection rate (ADR), hypoxemia, and obesity were newly-emergent research hot spots. Conclusions: Our findings showed that hypoxia, adverse event, and ADR, along with conscious sedation and propofol sedation, have been foci of endoscopic sedation research over the past 20 years. The research focus has shifted from sedative drugs to sedative complications and endoscopy quality control, which means that there will be higher requirements and standards for sedative quality and endoscopy quality in the future.

Efficacy of high flow nasal oxygenation against hypoxemia in sedated patients receiving gastrointestinal endoscopic procedures: A systematic review and meta-analysis

STUDY OBJECTIVE

To evaluate the impact of high flow nasal oxygenation (HFNO) on the risk of hypoxemia during gastrointestinal endoscopic procedures (GEPs) under sedation.

DESIGN

Meta-analysis of randomized controlled trials.

SETTING

Gastrointestinal endoscopy.

INTERVENTION

HFNO.

PATIENTS

Adults patients undergoing GEPs under sedation.

MEASUREMENTS

The primary outcome was risk of hypoxemia, while the secondary outcomes included risks of severe hypoxemia, hypercapnia, need for jaw thrust or other airway interventions, and procedural interruption as well as procedure time, minimum SpO₂, and level of carbon dioxide (CO₂). Analyses based on age, gender, flow rate, risk status of patients were performed to investigate subgroup effects.

RESULTS

Medline, Google scholar, Cochrane Library, and EMBASE databases were searched from inception to July 2021. Seven randomized controlled trials (RCTs) involving 2998 patients published from 2019 to 2021 were included. All GEPs were performed under propofol sedation. Pooled results revealed significantly lower risks of hypoxemia [relative risk (RR) = 0.31, 95% CI:0.13-0.75; 2998 patients], severe hypoxemia (RR = 0.38, 95% CI:0.2-0.74; 2766 patients), other airway interventions (RR = 0.34, 95% CI:0.22-0.52; 2736 patients), procedural interruption (RR = 0.12, 95% CI:0.02-0.64, 451 patients) and a lower CO₂ level [standard mean difference (MD) = -0.21, 95% CI: -0.4 to -0.03; 458 patients] in HFNO group compared to control group. Subgroup analysis focusing on risk of hypoxemia showed no significant subgroup effects, indicating consistent benefits of HFNO in different clinical settings. There were no difference in minimum SpO₂ (p = 0.06; 262 patients), risk of hypercapnia (p = 0.09; 393 patients), need for jaw thrust (p = 0.28; 2256 patients), and procedure time (p = 0.41, 1004 patients) between the two groups.

CONCLUSION

Our results demonstrated the efficacy of high flow nasal oxygenation for reducing the risk of hypoxemia in patients receiving elective gastrointestinal endoscopic procedures under sedation. Further studies are warranted to verify its cost-effectiveness in the gastrointestinal endoscopy setting.

Comparison of the innovative endoscopic oropharyngeal airway and the conventional mouthpiece in elderly outpatients undergoing esophagogastroduodenoscopy under sedation: a prospective and randomized study

Background

Undesirable outcomes may appear for elderly patients undergoing esophagogastroduodenoscopy (EGD) under sedation, such as hypoxia and hypotension. The aim of our study was to investigate the ability of the innovative endoscopic oropharyngeal airway to reduce the frequency of hypoxia during EGD under sedation in elderly patients.

Methods

In this trial, aged patients undergoing EGD were randomized into airway group and mouthpiece group. The primary outcome was the incidence of the minimum pulse oxygen saturation < 90% and minimum pulse oxygen saturation. In addition, sedation dose, recovery time, emergency management and adverse reactions were recorded.

Results

360 patients completed the study (180 in each groups). The minimum pulse oxygen saturation during EGD was significantly higher in airway group (97.66 ± 2.96%) than in mouthpiece group (95.52 ± 3.84%, P < 0.001). The incidence of pulse oxygen saturation of 85–89% of airway group (5.0%, 9/180) was lower than mouthpiece group (10.6%, 19/180, P = 0.049). The endoscopy entry time in airway group was 3 (2, 4) seconds and in mouthpiece group was 5 (4, 6) (P < 0.001). Propofol total dose and awakening time were significantly lower in the airway group than in the mouthpiece group (P = 0.020 and P = 0.012, respectively). Furthermore, the incidence rate of hypotension was significantly higher in mouthpiece group (12.2%) than in airway group (5.0%) (P = 0.015). By comparison with the mouthpiece group, the satisfaction of endoscopists was higher in airway group (P = 0.012).

Conclusion

Elderly patients undergoing EGD, Endoscopy Protector was associated with a significantly lower incidence of hypoxia, shortened endoscopy entry time and more stable hemodynamics.

Trial registration: ChiCTR, ChiCTR2000031998, 17/04/2020. http://www.chictr.org.cn/index.aspx

German S3 Guideline: Oxygen Therapy in the Acute Care of Adult Patients

BACKGROUND

Oxygen (O2) is a drug with specific biochemical and physiological properties, a range of effective doses and may have side effects. In 2015, 14% of over 55,000 hospital patients in the UK were using oxygen. 42% of patients received this supplemental oxygen without a valid prescription. Health care professionals are frequently uncertain about the relevance of hypoxemia and have low awareness about the risks of hyperoxemia. Numerous randomized controlled trials about targets of oxygen therapy have been published in recent years. A national guideline is urgently needed.

METHODS

A national S3 guideline was developed and published within the Program for National Disease Management Guidelines (AWMF) with participation of 10 medical associations. A literature search was performed until February 1, 2021, to answer 10 key questions. The Oxford Centre for Evidence-Based Medicine (CEBM) System ("The Oxford 2011 Levels of Evidence") was used to classify types of studies in terms of validity. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for assessing the quality of evidence and for grading guideline recommendation, and a formal consensus-building process was performed.

RESULTS

The guideline includes 34 evidence-based recommendations about indications, prescription, monitoring and discontinuation of oxygen therapy in acute care. The main indication for O2 therapy is hypoxemia. In acute care both hypoxemia and hyperoxemia should be avoided. Hyperoxemia also seems to be associated with increased mortality, especially in patients with hypercapnia. The guideline provides recommended target oxygen saturation for acute medicine without differentiating between diagnoses. Target ranges for oxygen saturation are based depending on ventilation status risk for hypercapnia. The guideline provides an overview of available oxygen delivery systems and includes recommendations for their selection based on patient safety and comfort.

CONCLUSION

This is the first national guideline on the use of oxygen in acute care. It addresses health care professionals using oxygen in acute out-of-hospital and in-hospital settings.

Comparison of a Nasal Mask and Traditional Nasal Cannula During Intravenous Anesthesia for Gastroscopy Procedures: A Randomized Controlled Trial

BACKGROUND:

Hypoxemia can occur during gastroscopy under intravenous anesthesia. The aim of this randomized controlled trial was to evaluate whether oxygenation using a nasal mask can reduce the incidence of hypoxemia during gastroscopy under intravenous anesthesia compared with a traditional nasal cannula.

METHODS:

A total of 574 patients scheduled for gastroscopy under intravenous anesthesia were enrolled and randomly assigned to receive either a nasal mask or a traditional nasal cannula for oxygenation. The primary outcome was the incidence of hypoxemia. The secondary outcomes included the incidence of severe hypoxemia, duration of hypoxemia, minimum oxygen saturation, the proportion of emergency airway management, length of procedure, recovery time, and the satisfaction of the anesthetist and gastroenterologists as well as other adverse events (including cough, hiccups, nausea and vomiting, reflux, aspiration, and laryngospasm).

RESULTS:

A total of 565 patients were included in the analysis: 282 patients in the nasal cannula group and 283 patients in the nasal mask group. The incidence of hypoxemia was lower in the nasal mask group (18.0%) than in the nasal cannula group (27.7%; relative risk [RR] = 0.65; 95% confidence interval [CI], 0.48–0.89; P = .006), and the hypoxemia lasted a median of 18.0 seconds (interquartile range, 10.0–38.8) in the nasal mask group and 32.5 seconds (20.0–53.5) in the nasal cannula group (median difference –14.50; 95% CI, −22.82 to −1.34; P = .047). The proportion of patients requiring emergency airway management was significantly lower in the nasal mask group (8.8%) than in the nasal cannula group (19.1%; RR, 0.46; 95% CI, 0.30–0.73; P < .001). No difference was found in the overall incidence of other adverse events between the 2 groups (nasal mask 20.8%; nasal cannula 17.0%; RR, 1.23; 95% CI, 0.87–1.73; P = .25). Satisfaction was higher with the nasal mask than with the nasal cannula from the perspective of anesthetists (96.1% for nasal mask versus 84.4% for nasal cannula; RR, 1.14; 95% CI, 1.08–1.20; P < .001) and gastroenterologists (95.4% for mask versus 81.9% for cannula; RR, 1.17; 95% CI, 1.10–1.24; P < .001). There were no significant differences in the incidence of severe hypoxemia, minimum oxygen saturation, length of procedure, or recovery time between the 2 groups.

CONCLUSIONS:

Nasal mask oxygenation reduced the incidence of hypoxemia during anesthesia for gastroscopy under intravenous anesthesia.