High-flow versus standard nasal cannula in morbidly obese patients during colonoscopy: A prospective, randomized 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.

Unveiling the impact of airways: A comparative analysis of oropharyngeal and nasopharyngeal airways in painless fiberoptic bronchoscopy

Background

This study compared the efficacy of oropharyngeal airways (OA) and nasopharyngeal airways (NA) in maintaining oxygenation during painless fiberoptic bronchoscopy (PFB) in patients sedated with remimazolam besylate.

Methods

Two hundred and fifty-two patients were randomized to the OA or NA group. Remimazolam besylate was used for anesthesia induction and maintenance in both groups. We measured and recorded several physiological parameters, including mean arterial pressure, heart rate and oxygen saturation (SpO2), at various time points: before anesthesia (T1), after anesthesia induction (T2), immediately after the bronchoscope reached the trachea (T3), during the procedure (T4), and 5 min after transfer to the post-anesthesia care unit (T5). The incidence and frequency of hypoxemia, minimum SpO2 during the procedure and patient awakening time after flumazenil administration were also recorded. Additionally, the relationship between minimum SpO2 and body mass index (BMI) was investigated.

Results

Patients in the NA group experienced a higher incidence of hypoxemia compared to the OA group. Patients in the OA group maintained higher SpO2 levels at T3 and had a higher minimum SpO2 during the procedure than the NA group. Furthermore, a significant negative correlation was observed between minimum SpO2 and BMI. Following flumazenil anesthesia reversal, nearly 97 % of patients awakened within 1 min.

Conclusions

This study suggests that OA may provide a better safety profile than NA by preserving respiratory function during PFB.

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.

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.).

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.

Hypercarbia and high-flow nasal oxygen use during anaesthesia - risking a failure to thrive?

Prevention of arterial oxygen desaturation during anaesthesia with high-flow nasal oxygen (HFNO) has gained greater acceptance for a widening range of procedures. However, during HFNO use there remains the potential for development of significant anaesthesia-associated apnoea or hypoventilation and the possibility of hypercarbia, with harmful cardiovascular or neurological sequelae. The aim of this study was to determine whether any HFNO-related hypercarbia adverse incidents had been reported on webAIRS, an online database of adverse anaesthesia-related incidents. Two relevant reports were identified of complications due to marked hypercarbia during HFNO use to maintain oxygenation. In both reports, HFNO and total intravenous anaesthesia were used during endoscopic procedures through the upper airway. In both, the extent of hypoventilation went undetected during HFNO use. An ensuing cardiac arrest was reported in one report, ascribed to acute hypercarbia-induced exacerbation of the patient's pre-existing pulmonary hypertension. In the other report, hypercarbia led to a prolonged duration of decreased level of consciousness post procedure, requiring ventilatory support. During the search, an additional 11 reports of postoperative hypercarbia-associated sedation were identified, unrelated to HFNO. In these additional reports an extended duration of severe acute hypercarbia led to sedation or loss of consciousness, consistent with the known effects of hypercarbia on consciousness. These 13 reports highlight the potential dangers of unrecognised and untreated hypercarbia, even if adequate oxygenation is maintained.

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.

Examination of stabilization of sedation by Nasal High Flow in patients with endoscopic retrograde cholangiopancreatography during sedation using Dexmedetomidine

INTRODUCTION

Dexmedetomidine is used for the sedation method in the case of endoscopic retrograde cholangiopancreatography (ERCP) for the purpose of relieving patient anxiety. It has been reported that CO2 accumulated during sedation causes an arousal reaction, so how to normalize CO2 during sedation can be improved by administration of the minimum necessary sedative.Nasal High Flow oxygen therapy (NHF) uses a mild positive pressure load that improves carbon dioxide washout and reduces rebreathing to improve respiratory function and therefore is widely used to prevent hypoxemia and hypercapnia. In this study, we will investigate whether the upper airway patency would be maintained and the hypercapnia and hypoxemia during sedation would be prevented, by applying NHF as a respiratory management method to patients undergoing ERCP under sedation.

METHODS/DESIGN

In a randomized comparative study of 2 groups, the NHF device use group and the nasal cannula use group, for adult patients who visited the Nagasaki University Hospital and underwent ERCP examination under sedation. For sedation, Dexmedetomidine will be used in combination with and Midazolam and evaluation by anesthesiologist. In addition, as an analgesic, pethidine hydrochloride was administered intravenously. The total dose of the analgesic pethidine hydrochloride used in combination is used as the primary endpoint. As a secondary evaluation item, the percutaneous CO2 concentration is evaluated with a TCO2 monitor to examine whether it is effective in preventing hypercapnia. Furthermore, we will evaluate the incidence of hypoxemia with a percutaneous oxygen saturation value of 90% or less, and examine whether the use of equipment is effective in preventing the occurrence of hypercapnia and hypoxemia.

DISCUSSION

The purpose of this study was to obtain evidence for the utility of NHF as a potential therapeutic device for patients undergoing an ERCP under sedation, assessed by determining if the incidence rates of hypercapnia and hypoxemia decreased in the NHF device group, compared to the control group that did not use of this device.

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.

A single‐sided trans‐nasal catheter for smooth and efficient oxygen delivery can improve the safety in patients undergoing pancreato‐biliary endoscopy under intravenous sedation: A randomized trial

Background

Pancreato‐biliary endoscopic procedures often need to be performed under deep intravenous sedation. The patients are at an increased risk of respiratory depression influenced by the anatomical dead space of the upper respiratory system. We aimed to evaluate the benefit of oxygen delivery through a single‐sided trans‐nasal catheter (TC) for patients undergoing pancreato‐biliary endoscopy.

Methods

Oxygen supplementation during the procedure was provided either by insertion of a single‐sided TC or insertion of a conventional nasal catheter (NC). A prospective, single‐blind, randomized controlled study was conducted in two groups.

Results

The number of patients who indicated a decrease in the peripheral transcutaneous oxygen saturation (SpO2; desaturation) was significantly lower in the TC group than in the counterpart (8/58; 13.8% vs. 26/58; 44.8% p < 0.001). The efficient oxygen delivery in the safe range was better conserved in the TC group than in the NC one. There was no adverse effect on both groups. The maximum SpO2 while the endoscopic procedure was significantly higher in the TC group (99.7% vs. 99.3% p = 0.016) and the minimum SpO2 was also significantly higher in the same group (97.7% vs. 94.1% p < 0.0001), which meant that the efficient oxygen delivery was better maintained in TC group than the NC group.

Conclusions

A single‐sided TC placed in the pharynx in patients undergoing pancreato‐biliary endoscopy prepares a superior condition of the patients for venous sedation, maintained hyper‐oxygen saturation and a relatively higher SpO2 level to be maintained in limited conditions to reduce the dead space with acceptable tolerance, as compared to the placement of a conventional NC.

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.

Effects of opioid-free propofol or remimazolam balanced anesthesia on hypoxemia incidence in patients with obesity during gastrointestinal endoscopy: A prospective, randomized clinical trial

There are presently no consensuses on the optimal sedation strategy for obese patients during gastrointestinal endoscopy. This study aim to explore the effects of opioid-free propofol or remimazolam balanced anesthesia on hypoxemia incidence in patients with obesity. A total of 264 patients were randomized to remimazolam + esketamine group (group R) or propofol + esketamine group (group P). Anesthesia in group P was administrated by propofol, esketamine and in group R by remimazolam, esketamine. The primary outcome was incidence of hypoxemia. Secondary outcomes were the time to loss of consciousness (LoC) and to recovery and the incidence of intraoperative and postoperative adverse reactions. We found the incidence of mild hypoxemia in group R was similar to that in group P (14.2% vs. 11.5%, p = 0.396). The incidence of severe hypoxemia in group R was significantly lower than Group P (4.2% vs. 9.2%, p = 0.019). The time to LoC in group R was longer than group P [Median (interquartile range, IQR): 53 s (45 to 61) vs. 50 s (42 to 54), p = 0.001]. The time to recovery from anesthesia in group R was less than group P [Median (IQR): 48 min (41 to 58) vs. 55.5 min (46 to 67), p<0.001]. There was no significant difference in the incidence of adverse events (p > 0.05 for all). We concluded that compared with propofol combined with esketamine, remimazolam combined with esketamine can reduce the incidence of severe hypoxemia during gastrointestinal endoscopy in obese patients. Clinical Trial Registration: www.chictr.org.cn, Identifier: ChiCTR2200065575.

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.

Efficacy of High-Flow Nasal Cannula versus Conventional Oxygen Therapy in Obese Patients during the Perioperative Period: A Systematic Review and Meta-Analysis

Background. Obesity is a risk factor for severe airway obstruction and hypoxemia. High-flow nasal cannula (HFNC) is considered as a novel method for oxygen therapy, but the efficacy of HFNC for obese patients is controversial. This meta-analysis aimed to assess the efficacy of HFNC compared with conventional oxygen therapy (COT) in obese patients during the perioperative period. Methods. We searched the PubMed, Embase, Web of Science, the Cochrane Library, and Google scholar databases for randomized controlled trials (RCTs) that compared the efficacy of HFNC with COT in obese patients during the perioperative period. The primary outcome was the incidence of hypoxemia, while the secondary outcomes included the lowest SpO2, the need for additional respiratory support, and the hospital length of stay (LOS). Results. Twelve trials with 798 obese patients during the perioperative period were included. Compared with COT, HFNC reduced the incidence of hypoxemia (RR, 0.60; 95% CI, 0.43 to 0.83; $P=0.002$ ; I2 = 24%; 8 RCTs; n = 458), increased the lowest SpO2 (MD, 2.88; 95% CI, 1.53 to 4.22; $P<0.0001$ ; I2 = 32%; 5 RCTs; n = 264), decreased the need for additional respiratory support (RR, 0.43; 95% CI, 0.21 to 0.88; $P=0.02$ ; I2 = 0%; 3 RCTs; n = 305), and shortened the hospital LOS (MD, −0.31; 95% CI, −0.57 to −0.04; $P=0.02$ ; I2 = 0%; 3 RCTs; n = 214). Conclusions. This meta-analysis showed that compared with COT, the use of HFNC was able to reduce the incidence of hypoxemia, increase the lowest SpO2, decrease the need for additional respiratory support, and shorten the hospital LOS in obese patients during the perioperative period. Well-organized trials with large sample size should be conducted to support our findings.

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.

Obesity and outcomes in patients undergoing upper airway surgery for obstructive sleep apnea

Objective

Obesity is frequently debated as a factor associated with increased postoperative complications. Specifically, upper airway surgeries for obstructive sleep apnea (OSA), a common comorbidity among obese patients, may be complicated by obesity’s impact on intraoperative ventilation. The aim of this retrospective study was to analyze the association of various degrees of obesity with postoperative outcomes in patients undergoing surgery for OSA.

Methods

The American College of Surgeons National Surgical Quality Improvement database between 2015 and 2019 was used to create a sample of patients diagnosed with OSA who underwent uvulopalatopharyngoplasty, tracheotomy, and surgeries at the base of tongue, maxilla, palate, or nose/turbinate. Inverse probability-weighted logistic regression and unadjusted multivariable logistic regression were used to compare outcomes of non-obese and obesity class 1, class 2, and class 3 groups (World Health Organization classification). Primary outcome was a composite of 30-day readmissions, reoperations, and/or postoperative complications, and a secondary outcome was all-cause same-day hospital admission.

Results

There were 1929 airway surgeries identified. The inverse probability-weighted regression comparing class 1, class 2, and class 3 obesity groups to non-obese patients showed no association between obesity and composite outcome and no association between obesity and hospital admission (all p-values > 0.05).

Conclusion

These results do not provide evidence that obesity is associated with poorer outcomes or hospital admission surrounding upper airway surgery for OSA. While these data points towards the safety of upper airway surgery in obese patients with OSA, larger prospective studies will aid in elucidating the impact of obesity.

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.

High-flow nasal cannula versus standard low-flow nasal cannula during deep sedation in patients undergoing radiofrequency atrial fibrillation catheter ablation: a single-centre randomised controlled trial

Background

To our knowledge, there are few trials studying the effect of high-flow nasal cannula (HFNC) during deep sedation. Our hypothesis is that high-flow nasal cannula (HFNC) will prevent hypoxemia and desaturation as compared to low-flow nasal cannula (LFNC) during prolonged deep sedation in patients with atrial fibrillation undergoing radiofrequency catheter ablation (RFCA).

Methods

A single-centre, randomised controlled trial with HFNC as the intervention and LFNC as the control group. A total of 94 adult patients per group undergoing elective radiofrequency atrial fibrillation catheter ablation under deep sedation. will be included. The primary outcome is the lowest oxygen saturation (SpO2). Secondary outcomes are as follows: the duration of lowest SpO2, cross over from oxygen therapy in both directions, incidence of SpO2 below 90% > 60 seconds, adverse sedation events, adverse effects of HFNC, mean CO2, peak CO2 and patients experience with oxygen therapy. The study will take place during the 2-day admission period for RFCA. Patients can fill out their questionnaires in the first week after treatment.

Discussion

HFNC is increasingly used as a technique for oxygen delivery in procedural sedation and analgesia. We hypothesise that HFNC is superior to the standard treatment LFNC in patients under deep sedation with respect to the incidence of desaturation. To our knowledge, there are no adequately powered clinical trial studies on the effects of HFNC in prolonged deep sedation.

Trial registration

ClinicalTrials.gov NCT04842253. Registered on 04 April 2021

Efficacy of high-flow nasal oxygenation against peri- and post-procedural hypoxemia in patients with obesity: a meta-analysis of randomized controlled trials

This meta-analysis aimed at investigating the efficacy of high-flow nasal oxygenation (HFNO) against hypoxemia in patients with obesity compared with conventional oxygenation therapy and non-invasive ventilation. Databases were searched from inception to August 2021. Studies involving peri- or post-procedural use of HFNO were included. The primary outcome was risk of hypoxemia, while the secondary outcomes included status of oxygenation and carbon dioxide elimination. Ten randomized controlled trials (RCTs) were included. We found that HFNO prolonged the safe apnea time at induction compared to control group [mean difference (MD) = 73.88 s, p = 0.0004; 2 RCTs] with no difference in risk of peri-procedural hypoxemia [relative risk (RR) = 0.91, p = 0.64; 4 RCTs], minimum SpO2 (MD = 0.09%, p = 0.95; 4 RCTs), PaO2 (MD = − 8.13 mmHg, p = 0.86; 3 RCTs), PaCO2 (MD = − 6.71%, p = 0.2; 2 RCTs), EtCO2 (MD = − 0.28 mmHg, p = 0.8; 4 RCTs) between the two groups. HFNO also did not improve postprocedural PaO2/FiO2 ratio (MD = 41.76, p = 0.58; 2 RCTs) and PaCO2 (MD = − 2.68 mmHg, p = 0.07; 2 RCTs). This meta-analysis demonstrated that the use of HFNO may be associated with a longer safe apnea time without beneficial impact on the risk of hypoxemia, oxygenation, and CO2 elimination in patients with obesity. The limited number of trials warranted further large-scale studies to support our findings.

A Comparison of Oxygenation Efficacy between High-Flow Nasal Cannulas and Standard Facemasks during Elective Tracheal Intubation for Patients with Obesity: A Randomized Controlled Trial

Obese patients are predisposed to rapid oxygen desaturation during tracheal intubation. We aimed to compare the risk of desaturation between high-flow nasal oxygenation (HFNO) and classical facemask oxygenation (FMO) during rapid sequence intubation for elective surgery in obese patients. Adults with a body mass index ≥30 kg·m−2 undergoing laparoscopic sleeve gastrectomy at a medical center were randomized into the HFNO group (n = 40) and FMO group (n = 40). In the HFNO group, patients used a high-flow nasal cannula to receive 30 to 50 L·min−1 flow of heated and humidified 100% oxygen. In the FMO group, patients received a fitting facemask with 15 L·min−1 flow of 100% oxygen. After 5-min preoxygenation, rapid sequence intubation was performed. The primary outcome was arterial desaturation during intubation, defined as a peripheral capillary oxygen saturation (SpO2) <92%. The risk of peri-intubation desaturation was significantly lower in the HFNO group compared to the FMO group; absolute risk reduction: 0.20 (95% confidence interval: 0.05−0.35, p = 0.0122); number needed to treat: 5. The lowest SpO2 during intubation was significantly increased by HFNO (median 99%, interquartile range: 97−100) compared to FMO (96, 92−100, p = 0.0150). HFNO achieved a higher partial pressure of arterial oxygen (PaO2) compared to FMO, with medians of 476 mmHg (interquartile range: 390−541) and 397 (351−456, p = 0.0010), respectively. There was no difference in patients’ comfort level between groups. Compared with standard FMO, HFNO with apneic oxygenation reduced arterial desaturation during tracheal intubation and enhanced PaO2 among patients with obesity.

A comparison of high-flow nasal cannula and standard facemask as pre-oxygenation technique for general anesthesia: A PRISMA-compliant systemic review and meta-analysis

BACKGROUND

Current practice guidelines recommend the use of nasal cannula as an alternative pre-oxygenation method for tracheal intubation. However, the efficacy of high-flow nasal oxygenation versus standard facemask oxygenation has not been fully evaluated.

METHODS

We searched PubMed, Cochrane Library, and ClinicalTrials.gov for English-language studies published from January 1, 2000 to November 30, 2021. We included randomized controlled trials which compared high-flow nasal oxygenation and facemask oxygenation as the pre-oxygenation maneuver. Primary outcome was arterial partial pressure of oxygen (PaO2) after pre-oxygenation. Secondary outcomes were safe apnea time, arterial desaturation during intubation, lowest peripheral capillary oxygen saturation during intubation, and patient comfort score. Random-effects models and Mantel-Haenszel method were used for data synthesis.

RESULTS

A total of 16 randomized controlled trials and 1148 patients were included. High-flow nasal oxygenation achieved a higher PaO2 compared with facemask, mean difference: 64.86 mm Hg (95% confidence interval [CI]: 32.33-97.40, P < .0001). Safe apnea time was longer in high-flow nasal oxygenation, mean difference: 131.03 seconds (95% CI: 59.39-202.66, P < .0001). There was no difference in the risk of peri-intubation desaturation or lowest peripheral capillary oxygen saturation between groups. Patient comfort score was higher in high-flow nasal oxygenation, mean difference: 1.00 (95% CI: 0.46-1.54, P = .0003).

CONCLUSION

High-flow nasal oxygenation better enhanced PaO2 and extended safe apnea time and is not inferior to facemask oxygenation in preventing desaturation during tracheal intubation. High-flow nasal oxygenation may be considered as an alternative method, especially for patients with a potential difficult airway.

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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL TRIAL REGISTRATION

ANZCTR 12618000445279.

High-flow nasal oxygenation reduces the risk of desaturation in adults receiving procedural sedation: a meta-analysis of randomized controlled trials

Background

Procedural sedation reduces patients’ discomfort and anxiety, facilitating performance of the examination and intervention. However, it may also cause adverse events, including airway obstruction and hypoxia. We conducted this systematic review and meta-analysis to evaluate the efficacy of high-flow nasal oxygenation (HFNO) compared with that of standard oxygen therapy in adult patients undergoing procedural sedation.

Methods

We identified randomized controlled trials published before November 2020 based on PubMed, Embase, and Cochrane Library databases and ClinicalTrials.gov registry. Intraprocedural desaturation [peripheral oxygen saturation (SpO₂) < 90%] was evaluated as the primary outcome. The secondary outcomes were the lowest SpO₂, need for airway intervention, oxygen therapy-related complications, and patient, operator, and anesthetist’s satisfaction.

Results

Six trials with a total of 2633 patients were reviewed. Patients using HFNO compared with standard oxygen therapy had a significantly lower risk of intraprocedural desaturation [risk ratio 0.18, 95% confidence interval (CI) 0.04-0.87]. The lowest intraprocedural SpO₂ in HFNO group was significantly higher than that in standard oxygen therapy group (mean difference 4.19%, 95% CI 1.74-6.65).

Conclusions

Compared with standard oxygen therapy, HFNO may reduce the risk of desaturation and increase the lowest SpO₂ in adult patients undergoing sedation for medical procedures.

High flow nasal oxygen, procedural sedation, and clinical governance

Procedural sedation for therapeutic and diagnostic procedures can now be achieved through deep sedation techniques that guarantee procedural success. Deep sedation techniques are delivered in a variety of non-theatre environments where the usual levels of anaesthetic equipment are not practical or economical. Hypoxic events are particularly frequent, and challenge sedation providers. Traditional low flow nasal or facial oxygen therapy techniques are often insufficient to maintain acceptable oxygen levels and prevent peri-procedural hypoxia. High flow nasal oxygen delivers warm humidified oxygen up to 70l/min, at oxygen concentrations between 21 - 100%, and reduces the incidence of hypoxic events. The provision of deep sedation is a complex process, fraught with risk, which can challenge even the skilled anaesthetist. Therefore, regulatory authorities previously stipulated that anaesthesia personnel be present during deep sedation. Changing attitudes by regulatory authorities and practical challenges providing anaesthesia specialists have led to the acknowledgement that appropriately trained non-anaesthetic staff can safely provide deep sedation. Deep sedation services are increasingly applied to subjects with complex comorbidities, sometimes excluded for safety reasons from surgery under general anaesthesia. The development of deep sedation services, delivered by non-anaesthesia personnel, to patients with complex co-morbidities requires that services implement appropriate clinical governance tools to prevent deep sedation being the wild west of anaesthesia services. Therefore, whilst high flow nasal oxygen may reduce the incidence of peri-procedural hypoxia, the introduction of clinical governance tools and the systematic introduction of initiatives to improve quality, will maintain the safety of deep sedation services.

High flow nasal oxygen during procedural sedation for cardiac implantable electronic device procedures: A randomised controlled trial

BACKGROUND

High flow nasal oxygen may better support the vulnerable respiratory state of patients during procedural sedation.

OBJECTIVE

The objective of this study was to investigate the effects of high flow nasal oxygen in comparison to facemask oxygen on ventilation during cardiac implantable electronic device procedures performed with procedural sedation.

DESIGN

A randomised controlled trial.

SETTING

The study was conducted at one academic hospital in Canada.

PARTICIPANTS

Adults undergoing elective cardiac implantable electronic device procedures with sedation administered by an anaesthesia assistant, supervised by an anaesthesiologist from August 2019 to March 2020.

INTERVENTIONS

Participants were randomised 1 : 1 to facemask (≥ 8 l · min-1) or high flow nasal oxygen (50 l · min-1 and a 50 : 50 oxygen to air ratio).

MAIN OUTCOME MEASURES

The primary outcome was peak transcutaneous carbon dioxide. Outcomes were analysed using Bayesian statistics.

RESULTS

The 129 participants who were randomised and received sedation were included. The difference in peak transcutaneous carbon dioxide was 0.0 kPa (95% CI -0.17 to 0.18). Minor adverse sedation events were 6.4 times more likely to occur in the high flow nasal oxygen group. This estimate is imprecise (95% CI 1.34 to 42.99). The odds ratio for oxygen desaturation for the high flow nasal oxygen group compared with the facemask group was 1.2 (95% CI 0.37 to 3.75). The difference in satisfaction with sedation scores between groups was 0.0 (95% CI -0.33 to 0.23).

CONCLUSIONS

Ventilation, as measured by TcCO2, is highly unlikely to differ by a clinically important amount between high flow nasal oxygen at 50 l min-1 or facemask oxygen at 8 l min-1. Further research with a larger sample size would be required to determine the optimal oxygen:air ratio when using high flow nasal oxygen during cardiac implantable electronic device procedures performed with sedation.

TRIAL REGISTRATION NUMBER

NCT03858257.

High-flow Nasal Oxygen Versus Standard Oxygen During Flexible Bronchoscopy in Lung Transplant Patients: A Randomized Controlled Trial

BACKGROUND

Diagnostic and interventional flexible bronchoscopy (FB) is increasingly utilized in complex and high-risk patients. Patients are often sedated for comfort and procedure facilitation and hypoxia is commonly observed in this setting. We hypothesized that high-flow nasal oxygen (HFNO) would reduce the incidence of patients experiencing oxygen desaturation.

METHODS

In this randomized controlled trial, postlung transplant patients booked for FB with transbronchial lung biopsy were assigned to either HFNO or low-flow nasal oxygen (LFNO). The patient and bronchoscopist were blinded to group allocation. The primary endpoint was the proportion of patients experiencing mild desaturation [peripheral oxygen saturation (SpO2)<94%]. Secondary endpoints included desaturation (SpO2<90%), the number of airway interventions required and procedure interruptions, the duration of oxygen desaturation and patient, bronchoscopist and anesthesiologist satisfaction scores.

RESULTS

The trial analyzed data from 76 patients (LFNO, n=39; HFNO, n=37). HFNO reduced the proportion of patients experiencing SpO2<94% (43.2% vs. 89.7%, P<0.001) and SpO2<90% (16.2% vs. 69.2%, P<0.001). The FB was interrupted 11 times in 9 patients in the LFNO group, whereas there were no interruptions in the HFNO group. There were no differences in patient and bronchoscopist satisfaction scores between groups, anesthesiologists had higher satisfaction scores when using HFNO (P<0.001).

CONCLUSION

Hypoxia occurred less commonly in postlung transplant patients receiving HFNO during FB. Further studies are warranted in other high-risk populations undergoing longer duration FB.

Effect of high-flow vs. low-flow nasal plus mouthguard oxygen therapy on hypoxaemia during sedation: a multicentre randomised controlled trial

Whether high-flow vs. low-flow nasal oxygen reduces hypoxaemia for sedation during endoscopic retrograde cholangiopancreatography is currently unknown. In this multicentre trial, 132 patients ASA physical status 3 or higher, BMI > 30 kg.m^-2 or with known or suspected obstructive sleep apnoea were randomly allocated to high-flow nasal oxygen up to 60 l.min^-1 at 100% F_I O₂ or low-flow nasal oxygen at 4 l.min^-1 . The low-flow nasal oxygen group also received oxygen at 4 l.min^-1 through an oxygenating mouthguard, totalling 8 l.min^-1 . Primary outcome was hypoxaemia, defined as S_p O₂ < 90% regardless of duration. Hypoxaemia occurred in 7.7% (5/65) of patients with high-flow and 9.1% (6/66) with low-flow nasal oxygen (percentage point difference -1.4%, 95%CI -10.9 to 8.0; p = 0.77). Between the groups, there were no significant differences in frequency of hypoxaemic episodes; lowest S_p O₂ ; peak transcutaneous carbon dioxide; hypercarbia (transcutaneous carbon dioxide > 2.66 kPa from baseline); requirement of chin lift/jaw thrust; nasopharyngeal airway insertion; bag-mask ventilation; or tracheal intubation. Following adjustment for duration of the procedure, the primary outcome remained non-significant. In high-risk patients undergoing endoscopic retrograde cholangiopancreatography, oxygen therapy with high-flow nasal oxygen did not reduce the rate of hypoxaemia, hypercarbia or the need for airway interventions, compared with combined oral and nasal low-flow oxygen.

Safety and efficacy of high flow nasal cannula therapy in acute hypercapnic respiratory failure - a retrospective audit

BACKGROUND

While the role of high flow nasal cannulae (HFNC) in the management of respiratory failure continues to expand, few studies describe its use in acute hypercapnic respiratory failure.

AIMS

In this retrospective study we assessed the safety and efficacy of HFNC for treatment of acute hypercapnic respiratory failure.

METHODS

Admissions with acute hypercapnic respiratory failure to a thoracic medicine unit at a tertiary centre between January and August 2018 were included if treated with either HFNC or non-invasive ventilation (NIV). The primary outcome was post-treatment change in arterial pCO₂ . Demographics, comorbidities, length of stay, readmission rate and mortality were also collected.

RESULTS

64 patients were identified, comprising 69 presentations grouped according to initial treatment: HFNC (n=24) or NIV (n=45). Patients in the NIV group had more severe blood gas derangement. In both groups, mean arterial pCO₂ improved significantly (-10 (95% CI: -14 to -6) mmHg) from baseline with no evidence of a differential effect between groups. Six (25%) patients were transitioned from HFNC to NIV, of whom 3 had comorbid obesity and 2 had sleep disordered breathing. No significant differences in hospital length of stay, 30-day readmission rate or 90-day mortality were observed.

CONCLUSIONS

HFNC may be a reasonable initial treatment for patients with mild acute hypercapnic respiratory failure who do not have comorbid obesity or sleep disordered breathing. Prospective study may help identify clinical factors or phenotypes predictive of success with this treatment modality. This article is protected by copyright. All rights reserved.

High-flow nasal oxygenation or standard oxygenation for gastrointestinal endoscopy with sedation in patients at risk of hypoxaemia: a multicentre randomised controlled trial (ODEPHI trial)

BACKGROUND

We aimed to determine whether high-flow nasal oxygen could reduce the incidence of decreased peripheral oxygen saturation (SpO₂) compared with standard oxygen in patients at risk of hypoxaemia undergoing gastrointestinal endoscopy under deep sedation.

METHODS

This was a multicentre, randomised controlled trial with blinded assessment of the primary outcome evaluating high-flow nasal oxygen (gas flow 70 L min^-1, inspired oxygen fraction 0.50) or standard oxygen delivered via nasal cannula or face mask (6 L min^-1) or nasopharyngeal tube (5 L min^-1) in patients at risk of hypoxaemia (i.e. >60 yr old, or with underlying cardiac or respiratory disease, or with ASA physical status >1, or with obesity or sleep apnoea syndrome) undergoing gastrointestinal endoscopy. The primary endpoint was the incidence of SpO₂ ≤92%. Secondary outcomes included prolonged or severe desaturations, need for manoeuvres to maintain free upper airways, and other adverse events.

RESULTS

In 379 patients, a decrease in SpO₂ ≤92% occurred in 9.4% (18/191) for the high-flow nasal oxygen group, and 33.5% (63/188) for the standard oxygen groups (adjusted absolute risk difference, -23.4% [95% confidence interval (CI), -28.9 to -16.7]; P<0.001). Prolonged desaturation (>1 min) and manoeuvres to maintain free upper airways were less frequent in the high-flow nasal oxygen group than in the standard oxygen group (7.3% vs 14.9%, P=.02, and 11.1% vs 32.4%, P<0.001).

CONCLUSIONS

In patients at risk of hypoxaemia undergoing gastrointestinal endoscopy under deep sedation, use of high-flow nasal oxygen significantly reduced the incidence of peripheral oxygen desaturation.

CLINICAL TRIAL REGISTRATION

NCT03829293.

Comparison of Oxygen Saturation Between Nasal High-Flow Oxygen and Conventional Nasal Cannula in Obese Patients Undergoing Dental Procedures With Deep Sedation: A Randomized Crossover Trial

PURPOSE

In anesthetic management, it is widely accepted that obese patients are more likely to suffer airway obstructions and reductions in arterial oxygen saturation (SpO₂). Therefore, it is important to take special measures to prevent oxygen desaturation during the deep sedation of obese patients. This clinical study examined whether the use of nasal high-flow systems (NHFS) keep higher SpO₂ and reduced hypoxemia than conventional nasal cannula during the deep sedation of obese patients with intellectual disabilities for dental treatment.

MATERIALS AND METHODS

Eighteen obese patients (body mass index: >25) with intellectual disabilities who underwent dental sedation were enrolled. In each case, sedation was induced using propofol and maintained at a bispectral index of 50 to 70. The subjects were randomly assigned to the control oxygen administration (5 L/min via a nasal cannula) or NHFS (40% O₂, 40 L/min, 37 °C) arm in alternate shifts as a crossover trial. The primary endpoint was the minimum SpO₂ value, and the incidence of hypoxemia during dental treatment was also evaluated.

RESULTS

The mean minimum SpO₂ value was significantly higher in the NHFS arm than in the control arm (95.8 ± 2.1 % vs 93.6 ± 4.1 %, P = 0.0052, 95% confidence interval: 0.608-3.947). Hypoxemic episodes (SpO₂: ≤94%) occurred 3 cases (16.7%) in the NHFS arm and 11 cases (61.1%) in the control arm (P = 0.0076, odds ratio: 0.127, 95% confidence interval 0.0324 - 0.630).

CONCLUSION

NHFS resulted in higher minimum SpO₂ and reduced hypoxemia than nasal cannula in obese patients during deep sedation for dental treatment.

[The Guideline "Sedation for Gastrointestinal Endoscopy"]

The guideline "Sedation for gastrointestinal endoscopy" (AWMF-register-no. 021/014) was published initially in 2008. Because of new and developing evidence, the guideline was updated in 2015. The aim of the guideline is to define the necessary structural, equipment and personnel requirements that contribute to minimizing the risk of sedation for endoscopy. In view of the high and increasing significance of gastrointestinal endoscopy, the guideline will remain highly relevant in the future. Essential aspects are the selection of sedatives/hypnotics, structural requirements, personnel requirements with regard to number, availability and training, management of complications and quality assurance. In this article, the development and evaluation of the evidence and its influence on the practical implementation, in particular for anaesthesia, are highlighted.