A screening instrument for sleep apnea predicts airway maneuvers in patients undergoing advanced endoscopic procedures

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.

ERCP-related adverse events: incidence, mechanisms, risk factors, prevention, and management

INTRODUCTION

Endoscopic retrograde cholangiopancreatography (ERCP) is a commonly performed procedure for pancreaticobiliary disease. While ERCP is highly effective, it is also associated with the highest adverse event (AE) rates of all commonly performed endoscopic procedures. Thus, it is critical that endoscopists and caregivers of patients undergoing ERCP have clear understandings of ERCP-related AEs.

AREAS COVERED

This narrative review provides a comprehensive overview of the available evidence on ERCP-related AEs. For the purposes of this review, we subdivide the presentation of each ERCP-related AE according to the following clinically relevant domains: definitions and incidence, proposed mechanisms, risk factors, prevention, and recognition and management. The evidence informing this review was derived in part from a search of the electronic databases PubMed, Embase, and Cochrane, performed on 1 May 20231 May 2023.

EXPERT OPINION

Knowledge of ERCP-related AEs is critical not only given potential improvements in peri-procedural quality and related care that can ensue but also given the importance of reviewing these considerations with patients during informed consent. The ERCP community and researchers should aim to apply standardized definitions of AEs. Evidence-based knowledge of ERCP risk factors should inform patient care decisions during training and beyond.

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

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.

Reliability of STOP-Bang questionnaire and pulse oximetry as predictors of OSA - a retrospective study

OBJECTIVE

To verify the reliability of a STOP-Bang questionnaire and objective blood oxygen concentration (SpO2) estimation by pulse oximetry as an indicator of patients' vulnerability to OSA, by correlating data of these two tests with that of the "gold standard" all-night polysomnography.

METHODS

STOP-Bang score and pulse oximetry value (SpO2) for each patient were tabulated against the total sleep AHI score (obtained from subsequent all-night polysomnography) and analyzed to evaluate the diagnostic accuracy of the STOP-Bang questionnaire and pulse oximetry.

RESULTS

With sensitivity and specificity scores of 91.2% and 88.6%, respectively, positive predictive value 90.5%, negative predictive value 40.2%, the twin diagnostic test (STOP-Bang and pulse oximetry) was found to be highly congruent with the polysomnography (PSG), achieving a diagnostic accuracy of 85%.

CONCLUSION

Dental chairside screening by STOP-Bang questionnaire and pulse oximetry would be a good option, especially where logistic and economic constraints impede all-night polysomnography.

Safety of endoscopist-administered deep sedation with propofol in patients ASA III

INTRODUCTION

Deep sedation controlled by the endoscopist is safe in patients with low anesthetic risk (ASA I-II). However, scarce evidence is available in patients with intermediate risk (ASA III).

OBJETIVE

To evaluate the safety of deep sedation with propofol controlled by the usual endoscopy staff (endoscopist, nurse, assistant) in outpatients classified as ASA III and the risk factors for the occurrence of complications during deep sedation in these patients.

DESIGN

This observational and single-centre cross-sectional study includes consecutive patients undergoing non-complex procedures in which deep sedation is administered by the endoscopy staff. Patients were divided into group I (ASA=III) and group II (ASA<III).

RESULTS

A total of 562 patients were included, 80 (14.2%) group I. Complications related to deep sedation were more frequent in group I (23.8% vs 14.5%; p=0.036), mainly mild desaturations (13.8% vs 7.5%; p=0.058). Emergency intervention or exitus were not registered. The adjusted analysis identified age as the one independent baseline risk factor for developing global adverse events.

CONCLUSION

ASA III patients developed more sedation-related complications that ASA I-II patients. However these complications were mild and do not prevent to correctly perform the procedure.

The correlation between the STOP-Bang score and oxygen saturation during spinal anesthesia with dexmedetomidine sedation

BACKGROUND

The STOP-Bang questionnaire is a simple screening tool with high sensitivity for the detection of severe obstructive sleep apnea. Predicting airway obstruction would allow the safe management of sedative patients to prevent intraoperative hypoxia. This study was designed to check the correlation between the STOP-Bang score and oxygen saturation (SpO2) during sedation and confirm the availability of the STOP-Bang questionnaire as a preoperative exam for predicting the incidence of hypoxia in sedative patient management.

METHODS

This study included 56 patients who received spinal anesthesia. The pre-anesthesia evaluation was conducted using the STOP-Bang questionnaire. The patients were under spinal anesthesia with an average block level of T10. Dexmedetomidine was infused with a loading dose of 1 μg/kg over 10 min and a maintenance dose of 0.5 μg/kg/h until the end of the procedure. The SpO2 of the patients was recorded every 5 min.

RESULTS

The STOP-Bang score was negatively correlated with the lowest SpO2 (coefficient = -0.774, 95% confidence interval [CI]: -0.855 to -0.649, standard error [SE] = 0.054, P < 0.001). The item of "observed apnea" was the most correlated one with hypoxic events (odds ratio = 6.00, 95% CI: 1.086 to 33.145).

CONCLUSIONS

The STOP-BANG score was significantly correlated with the lowest SpO2 during spinal anesthesia, which enabled the prediction of meaningful hypoxia before it occurred in the sedated patients.

Prediction of cardiopulmonary events using the STOP-Bang questionnaire in patients undergoing bronchoscopy with moderate sedation

The objective was to evaluate the prevalence of patients at a high risk of having OSA by using a screening questionnaire and to investigate whether the questionnaire can predict patients who are at risk of cardiopulmonary events occurring during a bronchoscopy under sedation. We prospectively enrolled consecutive adult patients who underwent flexible bronchoscopies under moderate sedation. The snoring, tiredness, observed apnea, high blood pressure-body mass index, age, neck circumference and gender (STOP-Bang) questionnaire was used to identify patients at a high (score ≥ 3 of 8) or low risk (score < 3 of 8) of having OSA. The cardiopulmonary events included hypoxemia and hypotension. Multivariable logistic regression was performed with variables selected by the least absolute shrinkage and selection operator. The prevalence of a STOP-Bang score of ≥ 3 was 67.2% (195/290), and 36.9% (107/290) experienced cardiopulmonary events. The multivariable analysis adjusting for chronic obstructive pulmonary disease, chronic kidney disease, baseline SpO₂, and procedure time revealed that a STOP-Bang score of ≥ 3 was significantly associated with cardiopulmonary events in a subgroup of patients without a history of cerebrovascular disease (adjusted odds ratio, 1.94; 95% confidence interval, 1.06-3.54). The STOP-Bang questionnaire can predict cardiopulmonary events occurring during this procedure.Trial registration: NCT03325153.

Propofol sedation with a target-controlled infusion pump in elderly patients undergoing ERCP

BACKGROUND AND AIMS

Advanced age is an important risk factor for adverse events (AEs) during propofol sedation for endoscopic procedures. This study aimed to evaluate the safety and efficacy of nonanesthesiologist-administered propofol (NAAP) sedation with a target-controlled infusion (TCI) system in elderly patients during ERCP.

METHODS

This study retrospectively analyzed 482 patients who underwent ERCP under propofol sedation with a TCI system at Iwakuni Medical Center between January 2014 and October 2016. Patients were divided into 3 groups according to their age: group A, <70 years (n = 130); group B, ≥70 and <85 years (n = 224); and group C, ≥85 years (n = 125). We compared the propofol dose and AEs during ERCP.

RESULTS

The median total infusion dose and minimum and maximum target blood concentrations of propofol were 336 mg, 2.2 μg/mL, and 2.2 μg/mL in group A; 184 mg, 1.0 μg/mL, and 1.4 μg/mL in group B; and 99 mg, .6 μg/mL, and 1.0 μg/mL in group C, respectively, with older groups requiring a lower dose (P < .0001). Hypotension was observed in 23 patients (4.8%), with no significant difference between groups (group A, 2.3%; group B, 6.3%; group C, 4.8%; P = .24). Hypoxemia was observed in 16 patients (3.3%), with no significant difference between groups (group A, 3.1%; group B, 4.9%; group C, .8%; P = .17). All AEs were immediately resolved, and no procedures were aborted.

CONCLUSIONS

NAAP sedation with a TCI system during ERCP may be acceptable in elderly patients with a lower dose of propofol than that used in younger patients.

High-flow nasal cannula versus standard oxygen therapy assisting sedation during endoscopic retrograde cholangiopancreatography in high risk cases (OTHER): study protocol of a randomised multicentric trial

Background

Endoscopic retrograde cholangiopancreatography (ERCP) is an increasingly common intervention in the treatment of pancreaticobiliary disorders. Patients are often elderly with complex co-morbidities. While monitored anaesthesia care with sedation is commonly used for most cases, few would require general anaesthesia with an endotracheal tube. Both low-flow and high-flow nasal cannulas (HFNC) are established ways of delivering supplemental oxygen, but it is unclear whether one technique is better than the other. HFNC seems a promising tool for advanced procedures but evidence to support its application in high-risk ERCP cases is limited. The rate of oxygen desaturation during endoscopy has been reported to be as high as 11%–50% and the method of oxygen delivery for ERCP merits further study.

Methods/design

This is a prospective, randomised, multicentre trial comparing the efficacy of oxygen supplementation through HFNC versus low-flow nasal cannula during ERCP, in a cohort of patients at risk of adverse respiratory events. A total of 132 patients will be recruited across three sites and randomly assigned to either the low-flow or the HFNC group. The primary outcome is the proportion of patients experiencing hypoxia, defined by any event of SpO2 < 90%. The secondary outcomes include parameters centred on oxygenation, requirement of airway manoeuvres, successful completion of procedure, perioperative complications, patient satisfaction and cost analysis of the consumables. An intention-to-treat principle will be applied while analysing.

Discussion

The demand for ERCPs is likely to increase in the future with the aging population. Our study results may lead to improved outcomes and reduce airway-related complications in patients undergoing ERCPs. The results will be presented at national and international meetings and published in peer-reviewed journals.

Trial registration

www.ANZCTR.org.au, CTRN12619000397112. Registered on 12 March 2019.

Creation of a score to predict risk of high conscious sedation requirements in patients undergoing endoscopy

BACKGROUND AND AIMS

The administration of intravenous conscious sedation to patients undergoing GI endoscopy carries a risk of cardiopulmonary adverse events. Our study aim was to create a score that stratifies the risk of occurrence of either high-dose conscious sedation requirements or a failed procedure.

METHODS

Patients receiving endoscopy via endoscopist-directed conscious sedation were included. The primary outcome was occurrence of sedation failure, which was defined as one of the following: (1) high-dose sedation, (2) the need for benzodiazepine/narcotic reversal agents, (3) nurse-documented poor patient tolerance to the procedure, or (4) aborted procedure. High-dose sedation was defined as >10 mg of midazolam and/or >200 μg of fentanyl or the meperidine equivalent. Patients with sedation failure (n = 488) were matched to controls (n = 976) without a sedation failure by endoscopist and endoscopy date.

RESULTS

Significant associations with sedation failure were identified for age, sex, nonclonazepam benzodiazepine use, opioid use, and procedure type (EGD, colonoscopy, or both). Based on these 5 variables, we created the high conscious sedation requirements (HCSR) score, which predicted the risk of sedation failure with an area under the curve of 0.70. Compared with the patients with a risk score of 0, risk of a sedation failure was highest for patients with a score ≥3.5 (odds ratio, 17.31; P = 2 × 10^-14). Estimated area under the curve of the HCSR score was 0.68 (95% confidence interval, 0.63-0.72) in a validation series of 250 cases and 250 controls.

CONCLUSIONS

The HCSR risk score, based on 5 key patient and procedure characteristics, can function as a useful tool for physicians when discussing sedation options with patients before endoscopy.

Snoring during Bronchoscopy with Moderate Sedation Is a Predictor of Obstructive Sleep Apnea

Background

Snoring is the cardinal symptom of obstructive sleep apnea (OSA). Snoring and upper airway obstruction associated with major oxygen desaturation may occur in populations undergoing flexible bronchoscopy.

Methods

To evaluate the prevalence of patients at a high risk of having OSA among patients undergoing bronchoscopy with sedation and to investigate whether snoring during the procedure predicts patients who are at risk of OSA, we prospectively enrolled 517 consecutive patients who underwent the procedure with moderate sedation. Patients exhibiting audible snoring for any duration during the procedure were considered snorers. The STOP-Bang (Snoring, Tiredness, Observed apnea, high blood Pressure-Body mass index, Age, Neck circumference and Gender) questionnaire was used to identify patients at high (score ≥3 out of 8) or low risk (score <3) of OSA.

Results

Of the 517 patients, 165 (31.9%) snored during bronchoscopy under sedation. The prevalence of a STOP-Bang score ≥3 was 61.9% (320/517), whereas 200 of the 352 nonsnorers (56.8%) and 120 of the 165 snorers (72.7%) had a STOP-Bang score ≥3 (p=0.001). In multivariable analysis, snoring during bronchoscopy was significantly associated with a STOP-Bang score ≥3 after adjustment for the presence of diabetes mellitus, chronic obstructive pulmonary disease, chronic kidney disease, and stroke (adjusted odds ratio, 1.91; 95% confidence interval, 1.26–2.89; p=0.002).

Conclusion

Two-thirds of patients undergoing bronchoscopy with moderate sedation were at risk of OSA based on the screening questionnaire. Snoring during bronchoscopy was highly predictive of patients at high risk of OSA.

A randomized controlled trial evaluating general endotracheal anesthesia versus monitored anesthesia care and the incidence of sedation-related adverse events during ERCP in high-risk patients

BACKGROUND AND AIMS

ERCP is a complex procedure often performed in patients at high risk for sedation-related adverse events (SRAEs). However, there is no current standard of care with regard to mode of sedation and airway management during ERCP. The aim of this study was to assess the safety of general endotracheal anesthesia (GEA) versus propofol-based monitored anesthesia care (MAC) without endotracheal intubation in patients undergoing ERCP at high risk for SRAEs.

METHODS

Consecutive patients undergoing ERCP at high risk for SRAEs at a single center were invited to participate in this randomized controlled trial comparing GEA and MAC. Inclusion criteria were STOP-BANG score ≥3, abdominal ascites, body mass index ≥35, chronic lung disease, American Society of Anesthesiologists class >3, Mallampati class 4 airway, and moderate to heavy alcohol use. Exclusion criteria were preceding EUS, emergent ERCP, tracheostomy, unstable airway, gastric outlet obstruction or delayed gastric emptying, and altered foregut anatomy. The primary endpoint was composite incidence of SRAEs: hypoxemia, use of airway maneuvers, hypotension requiring vasopressors, sedation-related procedure interruption, cardiac arrhythmia, and respiratory failure. Secondary outcomes included procedure duration, cannulation success, in-room time, and immediate adverse events.

RESULTS

Two hundred patients (mean age, 61.1 ± 13.6 years; 36.5% women) were randomly assigned to GEA (n = 101) or MAC (n = 99) groups. Composite SRAEs were significantly higher in the MAC group compared with the GEA group (51.5% vs 9.9%, P < .001). This was primarily driven by the frequent need for airway maneuvers in the MAC group. Additionally, ERCP was interrupted in 10.1% of patients in the MAC group to convert to GEA because of respiratory instability refractory to airway maneuvers (n = 8) or significant retained gastric contents (n = 2). There were no statistically significant differences in cannulation, in-room, procedure, or fluoroscopy times between the 2 groups. All patients undergoing GEA were successfully extubated in the procedure room at completion of ERCP, and Aldrete scores in recovery did not differ between the 2 groups. There were no immediate adverse events.

CONCLUSION

In patients at high risk for SRAEs undergoing ERCP, sedation with GEA is associated with a significantly lower incidence of SRAEs, without impacting procedure duration, success, recovery, or in-room time. These data suggest that GEA should be used for ERCP in patients at high risk for SRAEs (Clinical trial registration number: NCT02850887.).

An artificial neural network model for prediction of hypoxemia during sedation for gastrointestinal endoscopy

OBJECTIVE

This study was designed to assess clinical predictors of hypoxemia and develop an artificial neural network (ANN) model for prediction of hypoxemia during sedation for gastrointestinal endoscopy examination.

METHODS

A total of 220 patients were enrolled in this prospective observational study. Data on demographics, chronic concomitant disease information, neck circumference, thyromental distance and anaesthetic dose were collected and statistically analysed.

RESULTS

Univariate analysis indicated that body mass index (BMI), habitual snoring and neck circumference were associated with hypoxemia. An ANN model was developed with three variables (BMI, habitual snoring and neck circumference). The area under the receiver operating characteristic curve for the ANN model was 0.80.

CONCLUSIONS

The ANN model developed here, comprising BMI, habitual snoring and neck circumference, was useful for prediction of hypoxemia during sedation for gastrointestinal endoscopy.

A prediction model for hypoxemia during routine sedation for gastrointestinal endoscopy

OBJECTIVES

The current study was designed to assess the clinical predictors of hypoxemia and to develop a multivariable, predictive model for hypoxemia during routine gastrointestinal endoscopy.

METHODS

In total, 308 patients were enrolled in the analysis. Demographic data, concurrent chronic disease information, anesthetic dose and Modified Observer's Assessment of Alertness/Sedation (MOAA/S) scores were collected and analyzed statistically.

RESULTS

Multivariate logistic regression indicated that age (OR: 1.04; 95%CI 1.01-1.08), body mass index (BMI) (OR: 1.12; 95%CI: 1.02-1.21) and habitual snoring (OR: 3.71; 95%CI: 1.62-8.48) were independently associated with hypoxemia. A logistic regression function (LR model) was developed to predict hypoxemia considering the parameters of -7.73+0.04 age (years), +0.11 BMI, and +1.31 habitual snoring (yes or no). The area under the receiver operating characteristic (ROC) curve for the LR model was 0.76.

CONCLUSIONS

The LR model, consisting of age, BMI and habitual snoring, was a useful predictor of hypoxemia during routine sedation for gastrointestinal endoscopy.

An update on the various practical applications of the STOP-Bang questionnaire in anesthesia, surgery, and perioperative medicine

Purpose of review

The present review aims to provide an update on the various practical applications of the STOP-Bang questionnaire in anesthesia, surgery, and perioperative medicine.

Recent findings

The STOP-Bang questionnaire was originally validated as a screening tool to identify surgical patients who are at high-risk of obstructive sleep apnea (OSA). A recent meta-analysis confirmed that STOP-Bang is validated for use in the sleep clinic, surgical, and general population. Patients with a STOP-Bang score of 0--2 can be classified as low-risk for moderate-to-severe OSA. Those with a score of 5--8 can be classified as high-risk for moderate-to-severe OSA. In patients with a score of 3 or 4, a specific combination of a STOP score at least 2 + BMI more than 35 kg/m² or STOP score at least 2 + male or STOP score at least 2 + neck circumference more than 40 cm indicates higher risk for moderate-to-severe OSA. Further, patients with a STOP-Bang score at least 3 can be classified as high risk for moderate-to-severe OSA if the serum HCO₃^- at least 28 mmol/l. STOP-Bang can be used as a novel tool for perioperative risk stratification because it easily identifies patients who are at increased risk of perioperative complications.

Summary

STOP-Bang at least 3 was recommended previously to identify the suspected or undiagnosed OSA. To reduce the false positive cases and to improve its specificity, a stepwise stratification is recommended to identify the patients at high risk of moderate-to-severe OSA. Because of its practical application, STOP-Bang is a useful screening tool for patients with suspected or undiagnosed OSA.

Assessment of the Berlin Questionnaire for evaluation of hypoxemia risk in subjects undergoing deep sedation for screening gastrointestinal endoscopy

Background

Subjects with obstructive sleep apnea (OSA) are vulnerable to sedation-related complications during endoscopic procedures. A significant portion of subjects undergoing routine endoscopy is at high risk of OSA, but most are undiagnosed. The purpose of this study was to estimate the prevalence of high risk for OSA among Chinese subjects undergoing deep sedation for screening gastrointestinal endoscopy and to evaluate the hypoxemia risk of these examinees stratified by Berlin Questionnaire (BQ).

Patients and methods

We performed a prospective cohort study in subjects undergoing deep sedation with monitored anesthesia care for combined esophagogastroduodenoscopy plus colonoscopy. Subjects who were Chinese were stratified into high- and low-risk groups for OSA by administration of BQ. Deep sedation was achieved via a propofol target-controlled infusion system. Hypoxemia was defined as pulse oximetry reading of less than 90%. The frequency of hypoxemia was compared between high- and low-risk groups for OSA.

Results

A total of 615 Chinese subjects were recruited during the study period, and 614 subjects were included for analysis. Two hundred eighteen (35.5%) subjected were classified to be at high risk of OSA, and 396 (64.5%) were stratified to be at low risk of OSA by BQ. Hypoxemia occurred in 83 (13.5%) subjects during endoscopy procedures. The risk of developing hypoxemia in the high-risk group was significantly higher when compared to that of the low-risk group subjects (24.8% vs 7.3%; relative risk, 3.37; 95% CI, 2.22–5.13).

Conclusion

About one-third Chinese subjects undergoing deep sedation for screening endoscopy were at high risk of OSA. Subjects at high risk of OSA are associated with an increased risk of hypoxemia in comparison to the low-risk group when undergoing deep sedation for screening gastrointestinal endoscopy.

Society of Anesthesia and Sleep Medicine Guidelines on Preoperative Screening and Assessment of Adult Patients With Obstructive Sleep Apnea

Supplemental Digital Content is available in the text.

The purpose of the Society of Anesthesia and Sleep Medicine guideline on preoperative screening and assessment of adult patients with obstructive sleep apnea (OSA) is to present recommendations based on the available clinical evidence on the topic where possible. As very few well-performed randomized studies in this field of perioperative care are available, most of the recommendations were developed by experts in the field through consensus processes involving utilization of evidence grading to indicate the level of evidence upon which recommendations were based. This guideline may not be appropriate for all clinical situations and all patients. The decision whether to follow these recommendations must be made by a responsible physician on an individual basis. Protocols should be developed by individual institutions taking into account the patients’ conditions, extent of interventions and available resources. This practice guideline is not intended to define standards of care or represent absolute requirements for patient care. The adherence to these guidelines cannot in any way guarantee successful outcomes and is rather meant to help individuals and institutions formulate plans to better deal with the challenges posed by perioperative patients with OSA. These recommendations reflect the current state of knowledge and its interpretation by a group of experts in the field at the time of publication. While these guidelines will be periodically updated, new information that becomes available between updates should be taken into account. Deviations in practice from guidelines may be justifiable and such deviations should not be interpreted as a basis for claims of negligence.

Patients presenting for colonoscopy: A great opportunity to screen for sleep apnea

AIM

To discover the prevalence and the feasibility of screening for obstructive sleep apnea (OSA) in patients presenting for routine colonoscopy.

METHODS

Adult patients having a colonoscopy for routine indications at our outpatient endoscopy center were eligible if they did not carry a diagnosis of OSA or had not had a prior sleep study. All patients were administered the Berlin questionnaire prior to the procedure. Mallampati, neck circumference, height, weight, and BMI were obtained for each patient. Patients were observed for any drops in oxygen saturation < 92% or the presence of snoring for > 10 s. Patients were determined to be high-risk if they met at least 2 of the 3 symptom categories for the Berlin questionnaire.

RESULTS

A total of 60 patients were enrolled and completed the study; mean age was 56 years (range 23-72 year). Twenty-six patients had a positive Berlin questionnaire (43.3%), 31 patients had a negative Berlin questionnaire (51.6%) and 3 patients had an equivocal result (5.0%). Patients with a positive Berlin questionnaire were more likely to be of increased weight (mean 210.5 lbs vs mean 169.8 lbs, P = 0.003), increased BMI (33.0 kg/m²vs 26.8 kg/m², P = 0.0016), and have an increased neck circumference (38.4 cm vs 35.5 cm, P = 0.012). Patients with a positive Berlin questionnaire were more likely to have a drop in oxygen saturation < 92% (76.9% vs 36.4%, P = 0.01). Patients with snoring were more likely to have a positive Berlin questionnaire (8/9 patients vs 1/31 patients with negative Berlin questionnaire; P = 0.0045).

CONCLUSION

Risk for OSA is extremely common in a population presenting for a routine colonoscopy, and screening at the time of a colonoscopy offers an excellent opportunity to identify these patients.

Sedation Challenges: Obesity and Sleep Apnea

This article reviews the data for diagnostic and uncomplicated therapeutic upper endoscopy, which show it is safe and effective to perform the procedure under moderate sedation with a combination of benzodiazepine and opioids. For more complex procedures or for superobese patients anesthesia support is recommended. Performing endoscopy in this population should alert providers to plan carefully and individualize sedation plans because there is no objective way to quantify this risk pre-endoscopically.

Airway observations during upper endoscopy predicting obstructive sleep apnea

BACKGROUND

This pilot study examined airway characteristics during upper endoscopy to determine who is at high risk for obstructive sleep apnea.

METHODS

Patients undergoing routine upper endoscopy were divided into 2 groups according to the Berlin Questionnaire (high and low risk for sleep disordered breathing). Patients underwent routine upper endoscopy using propofol sedation. The airway was then evaluated for no, partial, or complete collapse at the levels of the palate/uvula/tonsils, the tongue base, the hypopharynx, and the larynx. They were given a score of 0 for no collapse, 1 for partial collapse, and 2 for complete collapse. The score for each of these levels was added to give a total score or severity index. The larynx was also evaluated for lateral pharyngeal collapse (minimal, up to 50%, >50%, or 100%).

RESULTS

We found that patients with a partial obstruction at the level of the palate/uvula/tonsils, tongue base, hypopharynx, or larynx, or complete obstruction at any level more often had a positive Berlin questionnaire. Patients with a positive Berlin questionnaire were more often of increased weight (mean 197 vs 175 lbs, P=0.19), increased body mass index (31.2 vs 27.42 kg/m², P=0.11), increased neck circumference (36.7 vs 34.7 cm, P=0.23), and had a higher total airway score (2.61 vs 1.67, P=0.09).

CONCLUSIONS

The results of our pilot study represent preliminary data regarding the use of upper endoscopy as a potential tool to evaluate patients for obstructive sleep apnea.

Sedation in the Endoscopy Suite

OPINION STATEMENT

Sedation practices in the endoscopy suite have changed dramatically in the decades since the introduction of routine colonoscopy and esophagogastroduodenoscopy (EGD). Patients initially received moderate sedation (or even no sedation), but now frequently receive monitored anesthesia care (MAC). This significant shift has introduced anesthesiologists to the endoscopy suite along with new sedative medications and safety concerns. Appreciating the ramifications of this change requires an understanding of sedation depth, patient selection, drug use, sedation delivery, patient monitoring, recovery from sedation, and patient outcomes. Furthermore, the changing landscape of healthcare quality and reimbursement challenges us to provide the best possible care for our patients in the most economical way possible. The endoscopy suite is a unique sedation environment, and it is the purpose of this article to review those elements that contribute to a uniquely demanding work environment.

Validation of the STOP-Bang Questionnaire as a Screening Tool for Obstructive Sleep Apnea among Different Populations: A Systematic Review and Meta-Analysis

BACKGROUND

Diagnosing obstructive sleep apnea (OSA) is clinically relevant because untreated OSA has been associated with increased morbidity and mortality. The STOP-Bang questionnaire is a validated screening tool for OSA. We conducted a systematic review and meta-analysis to determine the effectiveness of STOP-Bang for screening patients suspected of having OSA and to predict its accuracy in determining the severity of OSA in the different populations.

METHODS

A search of the literature databases was performed. Inclusion criteria were: 1) Studies that used STOP-Bang questionnaire as a screening tool for OSA in adult subjects (>18 years); 2) The accuracy of the STOP-Bang questionnaire was validated by polysomnography--the gold standard for diagnosing OSA; 3) OSA was clearly defined as apnea/hypopnea index (AHI) or respiratory disturbance index (RDI) ≥ 5; 4) Publications in the English language. The quality of the studies were explicitly described and coded according to the Cochrane Methods group on the screening and diagnostic tests.

RESULTS

Seventeen studies including 9,206 patients met criteria for the systematic review. In the sleep clinic population, the sensitivity was 90%, 94% and 96% to detect any OSA (AHI ≥ 5), moderate-to-severe OSA (AHI ≥15), and severe OSA (AHI ≥30) respectively. The corresponding NPV was 46%, 75% and 90%. A similar trend was found in the surgical population. In the sleep clinic population, the probability of severe OSA with a STOP-Bang score of 3 was 25%. With a stepwise increase of the STOP-Bang score to 4, 5, 6 and 7/8, the probability rose proportionally to 35%, 45%, 55% and 75%, respectively. In the surgical population, the probability of severe OSA with a STOP-Bang score of 3 was 15%. With a stepwise increase of the STOP-Bang score to 4, 5, 6 and 7/8, the probability increased to 25%, 35%, 45% and 65%, respectively.

CONCLUSION

This meta-analysis confirms the high performance of the STOP-Bang questionnaire in the sleep clinic and surgical population for screening of OSA. The higher the STOP-Bang score, the greater is the probability of moderate-to-severe OSA.

Patients With Roux-en-Y Gastric Bypass Require Increased Sedation During Upper Endoscopy

BACKGROUND & AIMS

After Roux-en-Y gastric bypass (RYGB), many patients experience changes in metabolism that could affect the amount of sedative they require. We assessed whether patients who have vs have not received RYGB have different sedation requirements during esophagogastroduodenoscopy (EGD).

METHODS

In a retrospective study, we collected data from patients who had received RYGB (n = 200; mean age, 45 years; 188 women; body mass index [BMI], 34.0 ± 7.1 kg/m2) or had not (controls, n = 200; mean age, 45 years; 188 women; BMI, 34.1 ± 7.2 kg/m2) and underwent EGD under conscious sedation from 2005 through 2010; groups were matched for age, sex, and BMI. Sedative doses were compared by using the Student t test. Multivariate linear regression was used to identify factors associated with sedation dose. We performed a subgroup analysis of RYGB patients who underwent EGD before and after RYGB, comparing sedative doses with a paired t test.

RESULTS

Patients with RYGB were given 132.4 ± 40.4 μg fentanyl and 5.4 ± 1.5 mg midazolam, whereas controls received 108.6 ± 31.6 μg fentanyl (P < .001) and 4.3 ± 1.2 mg midazolam (P < .001). Increased time from RYGB, higher American Society of Anesthesiologists class, and therapeutic procedure were associated with higher doses of sedation (P < .05). Thirty-two patients underwent EGD before and after RYGB. Patients were given 95.0 ± 39.0 μg fentanyl before RYGB and 130.5 ± 41.3 μg fentanyl afterward (P < .05); they were given 4.0 ± 1.0 mg midazolam before RYGB and 5.5 ± 1.7 mg midazolam afterward (P < .05).

CONCLUSIONS

Patients with RYGB require larger amounts of fentanyl and midazolam during EGD than patients without RYGB, despite similar age, sex, and BMI. Among patients who underwent EGD before and after RYGB, levels of drugs required for sedation increased after gastric bypass, despite weight loss.

Post-gastrointestinal endoscopy complications in patients with obstructive sleep apnea or at high risk for sleep apnea: a systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) is becoming increasingly more prevalent with the rise in obesity. Complications from gastrointestinal (GI) endoscopy in this patient population have been reported in several studies, but the modest complication rates from these procedures make it difficult to come to definitive conclusions based on single studies. The objective of our study was to systematically review these studies reporting the incidence of post-procedure complications in patients with OSA undergoing endoscopy to determine whether the presence of OSA increases post-procedure complications.

METHODS

We conducted a systematic review using the Cochrane Collaboration Methodology. We searched Medline via Ovid, PubMed, Embase, and Evidence Based Medicine Reviews databases from 1950 to August 2013. We rated the quality of evidence for each outcome using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. Meta-analysis was done using Review Manager Version 5.0.20.

RESULTS

Our search resulted in seven eligible studies. There was no significant association between diagnosis of OSA and post-GI endoscopy complications including hypoxemia, respiratory distress, variations in blood pressure or heart rate, bradypnea, or need for significant interventions. Subgroup analysis based on the type of GI endoscopy or the type of anesthesia used did not show any significant associations either.

CONCLUSIONS

Obstructive sleep apnea patients and/or patients at high risk for obstructive sleep apnea do not appear to be at increased risk of adverse outcomes from GI endoscopy.

Assessment of safety of non-anesthesiologist-assisted endoscopic retrograde cholangiopancreatography based on performance status in elderly patients

BACKGROUND AND AIM

Endoscopic retrograde cholangiopancreatography (ERCP) has been increasingly performed in the elderly patients, yet little is known concerning objective criteria of safety. This study aimed to determine the potential predictors for the procedure-related outcomes.

METHODS

Two hundred eighty-one patients older than 70 years who were indicated for ERCP (group A [n = 195], 70-79 years of age; group B [n = 86], ≥ 80 years of age) were prospectively enrolled and analyzed for the development of serious adverse events related to ERCP.

RESULTS

ERCP was not performed in six patients at high risk for the procedure. There were significant differences between group A and B in Duke Activity Status Index (DASI) (23.1 vs 14.9, P < 0.01) and Eastern Cooperative Oncology Group performance status (3 and 4, 49/195 vs 33/86, P < 0.05). Major ERCP-related complications (hypotension, severe bradycardia, hypoxia, myocardial infarction, cerebral infarction) occurred in five patients from group B and three from group A. Post-ERCP pancreatitis occurred in one patient from group A and bleeding in one from group B. In univariate analysis, old age (≥ 80 years), American Society of Anesthesiologists score ≥ 3, and DASI < 10 were statistically significant predictors for overall serious events related to ERCP. In the multivariate analysis, DASI < 10 (only manage to ambulate) was independent predictor for overall serious events related to ERCP.

CONCLUSION

DASI score is useful predictor for the feasibility assessment of safe ERCP in the elderly patients.

Can a validated sleep apnea scoring system predict cardiopulmonary events using propofol sedation for routine EGD or colonoscopy? A prospective cohort study

BACKGROUND

Obstructive sleep apnea (OSA), which is linked to the prevalence of obesity, continues to rise in the United States. There are limited data on the risk for sedation-related adverse events (SRAE) in patients with undiagnosed OSA receiving propofol for routine EGD and colonoscopy.

OBJECTIVE

To identify the prevalence of OSA by using the STOP-BANG questionnaire (SB) and subsequent risk factors for airway interventions (AI) and SRAE in patients undergoing elective EGD and colonoscopy.

DESIGN

Prospective cohort study.

SETTING

Tertiary-care teaching hospital.

PATIENTS

A total of 243 patients undergoing routine EGD or colonoscopy at Cleveland Clinic.

INTERVENTION

Chin lift, mask ventilation, placement of nasopharyngeal airway, bag mask ventilation, unplanned endotracheal intubation, hypoxia, hypotension, or early procedure termination.

MAIN OUTCOME MEASUREMENTS

Rates of AI and SRAE.

RESULTS

Mean age of the cohort was 50 ± 16.2 years, and 41% were male. The prevalence of SB+ was 48.1%. The rates of hypoxia (11.2% vs 16.9%; P = .20) and hypotension (10.4% vs 5.9%; P = .21) were similar between SB- and SB+ patients. An SB score ≥3 was found not to be associated with occurrence of AI (relative risk [RR] 1.07, 95% confidence interval [CI] 0.79-1.5) or SRAE (RR 0.81, 95% CI, 0.53-1.2) after we adjusted for total and loading dose of propofol, body mass index (BMI), smoking, and age. Higher BMI was associated with an increased risk for AI (RR 1.02; 95% CI, 1.01-1.04) and SRAE (RR 1.03; 95% CI, 1.01-1.05). Increased patient age (RR 1.09; 95% CI, 1.02-1.2), higher loading propofol doses (RR 1.4; 95% CI, 1.1-1.8), and smoking (RR 1.9; 95% CI, 1.3-2.9) were associated with higher rates of SRAE.

LIMITATIONS

Non-randomized study.

CONCLUSION

A significant number of patients undergoing routine EGD and colonoscopy are at risk for OSA. SB+ patients are not at higher risk for AI or SRAE. However, other risk factors for AI and SRAE have been identified and must be taken into account to optimize patient safety.

Preoperative screening and perioperative care of the patient with sleep-disordered breathing

PURPOSE OF REVIEW

Emerging data are raising concerns that patients with known or suspected obstructive sleep apnea (OSA) are at increased risk for a myriad of perioperative complications. Strategies to identify patients preoperatively with OSA, or at risk for OSA, are being advocated. In addition, approaches to identify patients most at risk for OSA-related postoperative complications have been described. While lacking solid evidence, a number of perioperative management strategies have been proposed for the care of these patients.

RECENT FINDINGS

Recent studies utilizing different methodologies have provided additional evidence regarding the impact that OSA can have on postoperative outcomes, including increased risk of difficult intubations, adverse pulmonary outcomes, and delirium. Tools, such as the STOP-Bang questionnaire and limited channel monitoring, have been investigated with regards to their utility to identify not only patients at risk for OSA but also those at risk for more severe OSA. Consensus-based guidelines for the perioperative care of OSA patients have recently been published.

SUMMARY

OSA is quite common in patients presenting for elective surgery and has been linked to increased perioperative complications. Attempts to identify these patients preoperatively appear prudent. Protocols on how best to manage these patients are available, although validation of their effectiveness is needed.

Balanced propofol sedation versus propofol monosedation in therapeutic pancreaticobiliary endoscopic procedures

BACKGROUND

Prolonged or complex endoscopic procedures are frequently performed under deep sedation. However, no studies of therapeutic ERCP have yet compared the use of balanced propofol sedation (BPS) to propofol alone, titrated to moderate levels of sedation.

AIM

This prospective, randomized, double-blind study was planned to compare the sedation efficacy and safety of BPS (propofol in combination with midazolam and fentanyl) and propofol monosedation in therapeutic ERCP and EUS.

METHODS

BPS, or propofol monosedation titrated to a moderate level of sedation, was performed by trained registered nurses under endoscopist supervision. The main outcome measurements included sedation efficacy focusing on recovery time, sedation safety, endoscopic procedure outcomes, and complications.

RESULTS

There were no significant differences in sedation efficacy, safety, procedure outcomes, and complications, with the exception of recovery time. Mean recovery time (standard deviation) was 18.37 (7.86) min in BPS and 13.4 (6.24) min in propofol monosedation (P < 0.001). In a safety analysis, cardiopulmonary complication rates related to BPS and propofol monosedation were 7.8 % (8/102) and 9.6 % (10/104), respectively (P = 0.652). No patient required assisted ventilation or permanent termination of a procedure in either group. Technical success of the endoscopic procedures was 96.3 and 97.2 %, respectively (P = 0.701). Endoscopic procedure-related complications and outcomes did not differ depending on sedation procedure.

CONCLUSIONS

Propofol monosedation by trained, registered sedation nurses under supervision resulted in a more rapid recovery time than BPS. There were no differences in the sedation safety, endoscopic procedure outcomes, and complications between BPS and propofol monosedation.

STOP questionnaire to screen for hypoxemia in deep sedation for young and middle-aged colonoscopy

BACKGROUND AND AIM

Hypoxemia is the most common unexpected cardiopulmonary complication that is used as a surrogate for severe complications in colonoscopy. The aim of the present study was to access the STOP Questionnaire to screen for hypoxemia in deep sedation for colonoscopy in young and middle-aged outpatients.

METHODS

Outpatients aged 18-65 with ASA class I or II who were to undergo elective colonoscopy with deep sedation were offered participation. Before sedation, the patients were given the STOP Questionnaire, a brief survey that stratifies patients into high or low risk of hypoxemia. Data on pulse oxygen saturation (SpO(2) ) were collected during sedation. Hypoxemia was defined as SpO(2)<95% anytime during the procedure, regardless of episode duration. We estimated the score of the STOP Questionnaire and the incidence of hypoxemia.

RESULTS

A total of 210 consecutive outpatients were offered enrollment. Thirteen (6.2%) patients had hypoxemia. Thirty-two (15.2%) patients were scored to be at high risk of hypoxemia, of whom 10 had hypoxemia. Results of analyzing the STOP Questionnaire for the incidence of hypoxemia were sensitivity 76.9%, specificity 88.8%, Youden's index 0.658, consistency rate 88%, kappa value 0.39, positive predictive value 31.3%, negative predictive value 98.3%, and area under receiver operating characteristic (ROC) curve 0.935 (P<0.001, 95% CI 0.879-0.991).

CONCLUSIONS

STOP Questionnaire is a validated and easy-to-use screening tool for hypoxemia in outpatient colonoscopy. It has high sensitivity, specificity and negative predictive value.

Sedation in the bariatric patient

Obesity is a significant health problem that has assumed epidemic proportions. A durable reduction in weight and improved morbidity and mortality have been realized with the introduction of various bariatric surgical procedures. It is unknown how safe the current practices of sedation for endoscopic procedures are in bariatric patients. Morbid obesity can result in pulmonary hypertension, obstructive sleep apnea, and restrictive lung disease. This article explores these issues and how they may impact the risk profile of current standards for endoscopic sedation.