Risk factors for cardiopulmonary events during propofol-mediated upper endoscopy and colonoscopy

Duration-Dependent Risk of Hypoxemia in Colonoscopy Procedures

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

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.

Nasal continuous positive pressure versus simple face mask oxygenation for adult obese and obstructive sleep apnea patients undergoing colonoscopy under propofol-based general anesthesia without tracheal intubation: A randomized controlled trial

STUDY OBJECTIVE

To determine if a nasal positive airway pressure (nasal CPAP) mask would decrease the number of hypoxemic events in obese and obstructive sleep apnea patients undergoing colonoscopy.

DESIGN

Single-center prospective randomized controlled trial.

SETTING

Tertiary academic center.

PATIENTS

We enrolled 109 patients with diagnosis of obesity and/or obstructive sleep apnea scheduled to undergo colonoscopy under propofol general anesthesia without planned tracheal intubation.

INTERVENTION

Patients were randomly allocated (1:1 ratio) to receive supplementary oxygen at a flow of 10 L/min, either through a nasal CPAP or a simple facemask.

MEASUREMENTS

The primary endpoint was the difference in the mean percentage of time spent with oxygen saturation below 90% between the two groups. Secondary outcomes included the need for airway maneuvers/interventions, average SpO2 during the case, duration and severity of oxygen desaturation, incidence and duration of procedural interruptions, and satisfaction and tolerance scores.

MAIN RESULTS

54 were allocated to the simple face mask and 55 to the nasal CPAP mask arms, respectively. A total of 6 patients experienced a hypoxemic event. Among these patients, the difference in the percentage of time spent with oxygen saturation below 90% was not clinically relevant (p = 1.0). However, patients in the nasal CPAP group required less chin lift (20% vs. 42.6%; p = 0.01) and oral cannula insertion (12.7% vs.29.6%; p = 0.03). The percentage of patients with at least one airway maneuver was higher in the simple face mask arm (68.5% vs. 41.8%; p = 0.005). Patient tolerance to device score was lower in the nasal CPAP group (8.85 vs. 9.56; p = 0.003).

CONCLUSIONS

A nasal CPAP did not prevent hypoxemia and should not be used routinely for colonoscopy in obese or OSA patients if a simple face mask is an alternative therapy. However, potential advantages of its use include fewer airway maneuvers or interventions, which may be desirable in certain clinical settings.

TRIAL REGISTRATION

Clinicaltrials.gov, identifier: NCT05175573.

Patient Safety during Propofol Sedation before and after Implementation of Capnography Monitoring

Endoscopic procedures are routinely applied to cancer screening programs and surveillance. The preferred technique is usually deep sedation with propofol being a convenient agent allowing for a quicker patient recovery while maintaining a similar safety profile compared to traditional agents. However, adverse events, including respiratory depression and consequent undesirable cardiovascular side effects, may occur. The goal of this work is to evaluate the patient safety impact of adding capnography during endoscopic procedures under deep propofol sedation. Data were retrospectively collected from patients undergoing deep, procedural sedation for gastrointestinal (GI) endoscopy in October 2019 to January 2021 in a single Turkish university hospital. Included in the analysis were all adult patients classified by the American Society of Anesthesiologists (ASA) as I-IV, who were scheduled for GI endoscopy utilizing propofol alone or in combination. Data on 1840 patients were collected, of whom 1610 (730 pre- and 880 post-capnography implemention) met inclusion criteria. The primary outcome was a change in the composite incidence of mild oxygen desaturation (SpO2 75-90% for <60 s), severe oxygen desaturation (SpO2 < 75% anytime or <90% for >60 s), bradycardia (<60 ppm), and tachycardia (>25% from baseline). Without capnography, on average, 7.5 events of the primary endpoint were observed per 100 procedures and 2.9 with additional capnography monitoring (p < 0.001). A significant reduction was observed for mild oxygen desaturation, with a resulting odds ratio of 0.25 (95% CI 0.14 to 0.46). ASA I patients had the highest difference in combined incidence of any oxygen desaturation of 5.85% in the pre-capnography group and 0.64% in the post-capnography group. Although procedural sedation using propofol is not associated with severe adverse events, the incidence of composite adverse events could be reduced with the addition of capnography monitoring.

Incidence and Nature of Respiratory Events in Patients Undergoing Bronchoscopy Under Conscious Sedation

BACKGROUND

During diagnostic bronchoscopies, conscious sedation improves patient tolerance, but it can contribute to hypercapnia and hypoxia by various mechanisms including depression of ventilatory drive. This prospective study was undertaken to determine the frequency of respiratory events and associated oxygen desaturations during bronchoscopy with conscious sedation.

PATIENTS AND METHODS

The Nox-T3 monitoring system was placed before starting the bronchoscopy and remained in place for 30 minutes following the procedure. The primary endpoint was the occurrence of obstructive and central apneic events during bronchoscopy under conscious sedation.

RESULTS

Obstructive events (apnea and hypopnea) occurred in 100% of patients (n=31), and central apneas occurred in 58% of patients (n=18) during the procedure with a median of 9 and 2 events per patient, respectively. During recovery, a significant proportion of patients had detectable obstructive (86%) and central (36%) events. Higher body mass index was associated with oxygen desaturation to <90% and with the need for escalation of care. Furthermore, a conscious sedation regimen that included propofol was significantly associated with central apneic events.

CONCLUSION

Respiratory events are common during and immediately postprocedure after conscious sedation for bronchoscopy. Most events are obstructive, and the use of propofol predisposes to central apneas during the procedure. Both types of events are associated with a higher body mass index. Oxygen desaturation to <90% triggers escalation of care. A further prospective study will be required to determine the clinical significance of these apneic events and whether alleviating these events will improve the safety and outcomes of bronchoscopic procedures performed under conscious sedation.

Practice Patterns and Predictors of Stopping Colonoscopy in Older Adults With Colorectal Polyps

BACKGROUND & AIMS

Older adults with colorectal polyps undergo frequent surveillance colonoscopy. There is no specific guidance regarding when to stop surveillance. We aimed to characterize endoscopist recommendations regarding surveillance colonoscopy in older adults and identify patient, procedure, and endoscopist characteristics associated with recommendations to stop.

METHODS

This was a retrospective cohort study at a single academic medical center of adults aged ≥75 years who underwent colonoscopy for polyp surveillance or screening during which polyps were found. The primary outcome was a recommendation to stop surveillance. Predictors examined included patient age, sex, family history of colorectal cancer, polyp findings, and endoscopist sex and years in practice. Associations were evaluated using multilevel logistic regression.

RESULTS

Among 1426 colonoscopies performed by 17 endoscopists, 34.6% contained a recommendation to stop and 52.3% to continue. Older patients were more likely to receive a recommendation to stop, including those 80-84 years (odds ratio [OR], 7.7; 95% confidence interval [CI], 4.8-12.3) and ≥85 years (OR, 9.0; 95% CI, 3.3-24.6), compared with those 75-79 years. Family history of colorectal cancer (OR, 0.42; 95% CI, 0.24-0.74) and a history of low-risk (OR, 0.17; 95% CI, 0.11-0.24) or high-risk (OR, 0.02; 95% CI, 0.01-0.04) polyps were inversely associated with recommendations to stop. The likelihood of a recommendation to stop varied significantly across endoscopists.

CONCLUSIONS

Only 35% of adults ≥75 years of age are recommended to stop surveillance colonoscopy. The presence of polyps was strongly associated with fewer recommendations to stop. The variation in endoscopist recommendations highlights an opportunity to better standardize recommendations following colonoscopy in older adults.

Oxygen desaturation during flexible bronchoscopy with propofol sedation is associated with sleep apnea: the PROSA-Study

BACKGROUND

Obstructive sleep apnea (OSA) is characterized by repetitive episodes of complete or partial obstruction of the upper airways during sleep. Conscious sedation for flexible bronchoscopy (FB) places patients in a sleep-like condition. We hypothesize that oxygen desaturation during flexible bronchoscopy may help to detect undiagnosed sleep apnea.

METHODS

Single-centre, investigator-initiated and driven study including consecutive patients undergoing FB for clinical indication. Patients completed the Epworth Sleepiness Scale (ESS), Lausanne NoSAS score, STOP-BANG questionnaire and the Berlin questionnaire and underwent polygraphy within 7 days of FB. FB was performed under conscious sedation with propofol. Oxygen desaturation during bronchoscopy was measured with continuous monitoring of peripheral oxygen saturation with ixTrend (ixellence GmbH, Germany).

RESULTS

145 patients were included in the study, 62% were male, and the average age was 65.8 ± 1.1 years. The vast majority of patients (n = 131, 90%) proved to fulfill OSA criteria based on polygraphy results: 52/131 patients (40%) had mild sleep apnea, 49/131 patients (37%) moderate sleep apnea and 30/131 patients (23%) severe sleep apnea. Patients with no oxygen desaturation had a significantly lower apnea-hypopnea index than patients with oxygen desaturation during bronchoscopy (AHI 11.94/h vs 21.02/h, p = 0.011). This association remained significant when adjusting for the duration of bronchoscopy and propofol dose (p = 0.023; 95% CI 1.382; 18.243) but did not hold when also adjusting for age and BMI.

CONCLUSION

The severity of sleep apnea was associated to oxygen desaturation during flexible bronchoscopy under conscious sedation. Patients with oxygen desaturation during bronchoscopy might be considered for sleep apnea screening.

TRIAL REGISTRATION

The Study was approved by the Ethics Committee northwest/central Switzerland, EKNZ (EK 16/13) and was carried out according to the Declaration of Helsinki and Good Clinical Practice guidelines. Due to its observational character, the study did not require registration at a clinical trial registry.

Endoscopist-directed propofol is more efficient than anesthesiologist-administered propofol in patients at low-intermediate anesthetic risk

OBJECTIVE

Endoscopist-directed propofol (EDP) sedation is becoming more popular, with a reported safety and efficacy similar to anesthesiologist-administered propofol (AAP). The aim of this study is to compare the efficiency of EDP and AAP in patients of low-intermediate anesthetic risk.

METHODS

A prospective cost-effectiveness comparison study was conducted. The costs of the endoscopic procedures in the EDP and AAP group were calculated using the full cost methodology after breaking down the endoscopic activity into relative value units to allocate costs in an equitable way. To determine the effectiveness, adverse events related to endoscopic sedation and the number of incomplete procedures were registered for the EDP group and compared with those published by anesthesiologists for AAP.

RESULTS

A total of 1165 and 18 919 endoscopic procedures were, respectively, included in the EDP and AAP groups. The average costs of EDP vs. AAP for gastroscopy, colonoscopy and endoscopic ultrasound were &OV0556; 182.81 vs. &OV0556; 332.93, &OV0556; 297.07 vs. &OV0556; 459.76, and &OV0556; 319.92 vs. &OV0556; 485.12, respectively. No significant differences were detected regarding the rate of overall adverse events (4.43 vs. 4.46%) or serious adverse events (0 vs. 0.17%); the rate of arterial hypotension was significantly lower in the EDP group: 0.34 vs. 1.78% [odds ratio (OR), 0.19; 95% confidence interval (CI), 0.08-0.46] and the desaturation rate was significantly lower in the AAP group: 3.26 vs. 1.29% (OR, 2.58; 95% CI, 1.85-3.60). No significant differences were found in terms of incomplete examinations (0.17 vs. 0.14%).

CONCLUSION

In patients with low-intermediate anesthetic risk referred for an endoscopic examination, EDP appears to be more efficient than AAP.

High-flow nasal oxygenation versus standard oxygenation for gastrointestinal endoscopy with sedation. The prospective multicentre randomised controlled ODEPHI study protocol

INTRODUCTION

Hypoxaemia is a major complication during gastrointestinal endoscopy (GIE) procedures (upper/lower) when performed under deep sedation in the procedure room. Standard oxygen therapy (SOT) is used to prevent hypoxaemia. Data suggest that risk factors for hypoxaemia under deep sedation during GIE are obstructive sleep apnoea syndrome, a body mass index above 30 kg/m², high blood pressure, diabetes, heart disease, age over 60 years old, high American Society of Anesthesiologists physical status class and the association of upper and lower GIE. High-flow nasal oxygenation (HFNO) may potentially improve oxygenation during GIE under deep sedation. We hypothesised that HFNO could decrease the incidence of hypoxaemia in comparison with SOT.

METHODS AND ANALYSIS

The ODEPHI (High-flow nasal oxygenation versus standard oxygenation for gastrointestinal endoscopy with sedation. The prospective multicentre randomised controlled) study is a multicentre randomised controlled trial comparing HFNO to SOT during GIE (upper and/or lower) under deep sedation administered by anaesthesiologists in the procedure room. Three hundred and eighty patients will be randomised with a 1:1 ratio in two parallel groups.The primary outcome is the occurrence of hypoxaemia, defined by a pulse oximetry measurement of peripheral capillary oxygen saturation (SpO₂) below or equal to 92% during the GIE procedure. Secondary outcomes include prolonged hypoxaemia, severe hypoxaemia, need for manoeuvres to maintain upper airway patency and other adverse events.

ETHICS AND DISSEMINATION

This study has been approved by the ethics committee (CPP Sud Est Paris V, France), and patients are included after informed consent. The results will be submitted for publication in peer-reviewed journals. As provided for by French law, patients participating in the study are informed that they have the possibility to ask the investigators, once the study is completed, to be informed of the overall results of the study. Thus, a summary of the results will be sent by post to the participants on request.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03829293).

Effect of electroacupuncture on sedation requirements during colonoscopy: a prospective placebo-controlled randomised trial

INTRODUCTION

Propofol provides excellent sedation during colonoscopy. However, its application, namely when used together with an opioid, is associated with cardiopulmonary depression. Acupuncture is used nowadays for the treatment of pain and anxiety, and also to induce sedation. We hypothesised that electroacupuncture (EA) during colonoscopy would have sedative effects, thereby reducing propofol requirements to achieve an adequate level of sedation.

METHOD

The study was designed and conducted as a single centre, patient and observer blinded, sham- and placebo-controlled randomised trial. Patients scheduled for elective colonoscopy under deep propofol/alfentanil sedation were randomly assigned to receive unilateral EA, sham-acupuncture (SA) or placebo-acupuncture (PA) at ST36, PC6 and LI4. The primary outcome parameter was the total dosage of propofol. Secondary outcomes included the patients' and endoscopists' satisfaction levels evaluated by questionnaires.

RESULTS

The dosage of propofol required (median [IQR]) was not significantly different between the three groups (EA group 147 μg/kg/min [109-193] vs SA group 141 μg/kg/min [123- 180] vs PA group 141 μg/kg/min [112-182]; P=0.776). There was also no significant difference in alfentanil consumption (P=0.634). Global satisfaction (median [IQR]) among patients (EA group 6.6 [6.0-7.0] vs SA group 6.8 [6.0-7.0] vs PA group 6.5 [6.0-7.0]; P=0.481) and endoscopists (6.0 [5.0-6.0] for all groups; P=0.773) did not significantly differ between the three groups. There was no significant difference in the number of cardiorespiratory events.

CONCLUSION

For colonoscopy, the applied mode of EA did not show any propofol-sparing sedative effect compared with sham or placebo acupuncture.

TRIAL REGISTRATION

The trial is registered in the Netherland's Trial Registry (NTR4325).

Partnership with Interventional Pulmonologist: An Anesthesiologist's Perspective

Via the emergence of new bronchoscopic technologies and techniques, there is enormous growth in the number of procedures being performed in nonoperating room settings. This, coupled with a greater focus from the Centers for Medicare and Medicaid Services for mandated anesthesiology oversight of procedural sedation for bronchoscopy by the pulmonologists has led to a more frequent working partnership between interventional pulmonologists and anesthesiologists. This article offers the interventional pulmonologist insight into how the anesthesiologist thinks and approaches anesthetic care delivery.

Propofol administration by endoscopists versus anesthesiologists in gastrointestinal endoscopy: a systematic review and meta-analysis of patient safety outcomes

BACKGROUND

With a growing demand for endoscopic services, the role of anesthesiologists in endoscopy units must be reassessed. The aim of this study was to compare patient outcomes in non-anesthesiologist-administered propofol (NAAP) versus anesthesiologist-administered propofol (AAP) during routine endoscopy.

METHODS

We systematically searched MEDLINE, CINAHL, Embase, Web of Science, CENTRAL and the grey literature for studies comparing NAAP and AAP. Primary outcomes included endoscopy- and sedation-related complications. Secondary outcomes included measures of endoscopy quality and of patient and endoscopist satisfaction. We reported treatment effects using random-effects models.

RESULTS

Of 602 articles identified, 5 met the inclusion criteria. Most studies included only patients with an American Society of Anesthesiologists (ASA) classification of I or II. Non-anesthesiologist-administered propofol did not result in increased rates of airway intervention (odds ratio [OR] 1.07, 95% confidence interval [CI] 0.29 to 3.95; 3443 patients) or hypotension (OR 1.47, 95% CI 0.40 to 5.41; 17 978 patients) but did result in higher rates of bradycardia (OR 3.68, 95% CI 1.65 to 8.17; 17 978 patients). Nonanesthesiologists administered lower propofol dosages than anesthesiologists (mean difference -61.79, 95% CI -114.46 to -9.12; 3443 patients), and their patients more commonly experienced awareness with recall (OR 19.99, 95% CI 7.88 to 50.76; 2090 patients). However, NAAP neither compromised patient willingness to repeat the procedure (OR 0.42, 95% CI 0.10 to 1.83; 2367 patients) nor lengthened total procedure time (mean difference -0.08, 95% CI -3.51 to 3.34; 2367 patients).

CONCLUSION

Endoscopists may safely administer propofol without compromising procedural quality in patients classified as ASA I or II undergoing routine endoscopy. The results of this meta-analysis are limited by a lack of available high-quality studies. Further, large-scale studies are needed for definitive conclusions.

Frailty Assessment Predicts Acute Outcomes in Patients Undergoing Screening Colonoscopy

BACKGROUND

Colonoscopy is associated with multiple adverse outcomes. With an aging population undergoing colorectal cancer screening, few modalities exist to assess the patient risk prior to colonoscopy. Frailty, the age-related decline in reserve and function across multiple organ systems, predicts poor surgical outcomes, but its role in endoscopy is unclear.

AIMS

This prospective cohort study assesses the efficacy of frailty in predicting acute colonoscopy outcomes.

METHODS

Participants aged ≥ 50 years undergoing screening colonoscopy at a tertiary care center were recruited over 2 months ending in July 2017. Frailty was assessed using a validated 20-s upper-extremity frailty test, which measures the capacity of muscle performance. Demographic data, American Society of Anesthesiologists (ASA) status, and Charlson comorbidity index (CCI) were evaluated. Procedure-related adverse events and cardiopulmonary changes during and in the immediate post-procedure period were recorded. Adverse events were stratified into minor and major events. Chi-square and ANCOVA models were used in the analysis.

RESULTS

Ninety-nine adults (mean age 62.8 years) were enrolled, among which 49 were non-frail and 50 were pre-frail/frail; 50 were female. Overall, 55 participants experienced a total of 87 adverse events. Frailty and ASA status were significantly associated with colonoscopy adverse events (p = 0.01 and p = 0.02, respectively). Age and CCI did not predict colonoscopy outcomes.

CONCLUSIONS

Compared to age and CCI, frailty status better predicts colonoscopy outcomes in older adults. Among adults undergoing colonoscopy, routine frailty screening should be considered for risk stratification. Additional prospective studies evaluating frailty measurements in endoscopy will further clarify its role in forecasting adverse events.

Incidence and risk factors for adverse events during anesthesiologist-led sedation or anesthesia for diagnostic imaging in children: a prospective, observational cohort study

Background

Pediatric sedation for diagnostic radiological procedures remains the mainstay for adequate imaging quality.

Objectives

To clarify the risk of adverse events during anesthesiologist-led sedation or anesthesia for diagnostic radiological procedures in children in order to improve quality of care.

Methods

We enrolled children aged <15 years given sedation or anesthesia by an anesthesiologist and scheduled for computed tomography, magnetic resonance imaging, or nuclear medicine imaging November 2010-September 2014. We recorded adverse events occurring in the first 24 h.

Results

Of 1,042 patients enrolled, adverse events were recorded in 254 (24.4%, 95% confidence interval [CI] 21.9 to 27.1). Adverse respiratory events occurred in 31 (3.0%), cardiovascular events in 7 (0.7%), sedation was prolonged in 165 (15.8%), there was one case of contrast allergy (0.01%), and there were 50 other minor complications (4.9%). Of the respiratory complications, there were 14 of airway obstruction (1.3%), 2 of apnea (0.2%), 14 of oxygen desaturation (1.3%), and one of laryngospasm (0.01%). There were no life threatening complications or consequences. Age <1 year (adjusted odds ratio [adjusted OR] 2.5, 95% CI 1.2 to 5.3) and American Society of Anesthesiologists (ASA) physical status classification 2 and 3 (adjusted OR 4.6, 95% CI 1.1 to 19.8, and adjusted OR 6.3, 95% CI 1.3 to 30.9, respectively) were risk factors for respiratory complications.

Conclusions

Adverse events were common during sedation or anesthesia, but no life threatening or sentinel events occurred under experienced supervision. Caution should be exercised in children <1 year or with an ASA classification >1.

Complications of diagnostic colonoscopy, upper endoscopy, and enteroscopy

Endoscopy is an inherent and an invaluable tool in every gastroenterologist's armamentarium. The prerequisite for quality and safety remains foremost. Adverse events should be minimized and proactive steps should taken before, during and after the endoscopic procedure. Upper endoscopy and colonoscopy are part of basic endoscopy and their major complications will be reviewed here, together with those of enteroscopy. The most common of all endoscopy related complications are cardiopulmonary and thus they will be addressed in detail first. Colonoscopy's major complications are bleeding and perforation. Their epidemiology, mechanisms/risk factors, diagnosis, treatment and prevention will be addressed. The incidence of both of these complications increases significantly with polypectomy. Thus clinical judgment and experience in both polypectomy techniques and the ways to treat these complications, especially with the advanced endoscopic options advanced in the last decade, are of paramount importance. Post-polypectomy syndrome, infection and gas explosion are less frequent and will be reviewed briefly. Bleeding and perforation are upper endoscopy's major complications as well. Advances in endoscopic techniques in recent years offer endoscopic treatment instead of directly resorting to surgery, as was used to be the case and still is if the first fails. Enteroscopy is generally a more advanced procedure and overall complication rate is often quoted as 1%, most of them have been attributed to the passage of the overtube. Perforation and bleeding are the major complications, and a unique upper enteroscopy-associated complication is pancreatitis.

Predictive Factors of Atelectasis Following Endoscopic Resection

BACKGROUND AND AIM

Atelectasis is one of the pulmonary complications associated with anesthesia. Little is known about atelectasis following endoscopic procedures under deep sedation. This study evaluated the frequency, risk factors, and clinical course of atelectasis after endoscopic resection.

METHODS

A total of 349 patients who underwent endoscopic resection of the upper gastrointestinal tract at a single academic tertiary referral center from March 2010 to October 2013 were enrolled. Baseline characteristics and clinical data were retrospectively reviewed from medical records. To identify atelectasis, we compared the chest radiography taken before and after the endoscopic procedure.

RESULTS

Among the 349 patients, 68 (19.5 %) had newly developed atelectasis following endoscopic resection. In univariate logistic regression analysis, atelectasis correlated significantly with high body mass index, smoking, diabetes mellitus, procedure duration, size of lesion, and total amount of propofol. In multiple logistic regression analysis, body mass index, procedure duration, and total propofol amount were risk factors for atelectasis following endoscopic procedures. Of the 68 patients with atelectasis, nine patients developed fever, and six patients displayed pneumonic infiltration. The others had no symptoms related to atelectasis.

CONCLUSIONS

The incidence of radiographic atelectasis following endoscopic resection was nearly 20 %. Obesity, procedural time, and amount of propofol were the significant risk factors for atelectasis following endoscopic procedure. Most cases of the atelectasis resolved spontaneously with no sequelae.

Morbidity and mortality of endoscopist-directed nurse-administered propofol sedation (EDNAPS) in a tertiary referral center

BACKGROUND AND STUDY AIMS

Endoscopist-Directed Nurse-Administered Propofol Sedation (EDNAPS) has been evaluated in community settings rather than tertiary referral centers.

PATIENTS AND METHODS

A hospital-wide prospectively collected database of Medical Emergency Team Calls (METCALL), emergency responses triggered by medically unstable patients, was reviewed. Responses that followed EDNAPS were extracted and compared with a prospectively entered database of all endoscopies performed using EDNAPS over the same period.

RESULTS

A total of 33,539 endoscopic procedures (16,393 gastroscopies, 17,146 colonoscopies) were performed on 27,989 patients using EDNAPS. Intravenous drugs included midazolam (0 - 5 mg), fentanyl (0 - 100 mcg), and propofol (10 - 420 mg). Of 23 METCALLs (18 gastroscopies and 5 colonoscopies), there were 16 with ASA scores of III or higher. Indications for gastroscopy were gastrointestinal (GI) hemorrhage (n = 11; 8 variceal, 3 nonvariceal), dysphagia (n = 5), PEG removal (n = 1), and dyspepsia (n = 1). Fifteen of 22 patients, including all of those who had a colonoscopy, made a full recovery and returned to the ward or were discharged home. In the gastroscopy group, seven were intubated and admitted to Intensive Care, of whom six were emergency cases for gastrointestinal bleeding (n = 4 variceal, n = 2 non variceal) and one in which the indication was PEG removal. Two deaths occurred in the intubated group.

CONCLUSIONS

In a tertiary referral center, EDNAPS for low-to-moderate risk (ASA ≤ 2) patients undergoing gastroscopy and colonoscopy is very safe. Gastroscopy is associated with greater anesthetic risk than colonoscopy and those with high ASA scores needing urgent endoscopy for upper gastrointestinal hemorrhage are at particular risk of cardiorespiratory decompensation.

The impact of anesthesia providers on major morbidity following screening colonoscopies

BACKGROUND AND AIMS

Few studies evaluate the impact of anesthesia providers during procedures, such as colonoscopy, on low-risk patients. The objective of this study was to compare the effect of anesthesia providers on several outcome variables, including major morbidity, following screening colonoscopies.

METHODS

A propensity-matched cohort study of 14,006 patients who enrolled with a national insurer offering health maintenance organization (HMO), preferred provider organization (PPO), and Medicare Advantage plans for a screening colonoscopy between July 1, 2005 and June 30, 2007 were studied. Records were evaluated for completion of the colonoscopy, new cancer diagnosis (colon, anal, rectal) within 6 months of the colonoscopy, new primary diagnosis of myocardial infarction (MI), new primary diagnosis of stroke, hospital admission within 7 days of the colonoscopy, and adherence to guidelines for use of anesthesia providers.

RESULTS

The presence of an anesthesia provider did not affect major morbidity or the percent of completed exams. Overall morbidity within 7 days was very low. When an anesthesia provider was present, a nonsignificant trend toward greater cancer detection within 6 months of the procedure was observed. Adherence to national guidelines regarding the use of anesthesia providers for low-risk patients was poor.

CONCLUSION

A difference in outcome associated with the presence or absence of an anesthesia provider during screening colonoscopy in terms of MI, stroke, or hospital admission within 7 days of the procedure was not observed. Adherence to published guidelines for the use of anesthesia providers is low. The incidence of completed exams was unaffected by the presence of an anesthesia provider. However, a nonstatistically significant trend toward increased cancer detection requires further study.

Monitored anesthesia care without endotracheal intubation is safe and efficacious for single-balloon enteroscopy

BACKGROUND

General endotracheal (GET) anesthesia is often used during single-balloon enteroscopy (SBE). However, there is currently limited data regarding monitored anesthesia care (MAC) without endotracheal intubation for this procedure.

AIMS

The aim of the study was to determine the safety and efficacy of MAC sedation during SBE and to identify risk factors for adverse events.

METHODS

All patients who underwent SBE and SBE-assisted endoscopic retrograde cholangiopancreatography between June 2011 and July 2013 at a tertiary-care referral center were studied in a retrospective analysis of a prospectively collected database. Patients received MAC anesthesia or GET. The main outcome measurements were sedation-related adverse events, diagnostic yield, and therapeutic yield.

RESULTS

Of the 178 cases in the study, 166 cases (93 %) were performed with MAC and 12 (7 %) with GET. Intra-procedure sedation-related adverse events occurred in 17 % of cases. The most frequent event was transient hypotension requiring pharmacologic intervention in 11.8 % of procedures. In MAC cases, the diagnostic yield was 58.4 % and the therapeutic yield was 30.1 %. Anesthesia duration was strongly associated with the occurrence of a sedation-related adverse event (P = 0.005).

CONCLUSIONS

MAC is a safe and efficacious sedation approach for most patients undergoing SBE. Sedation-related complications in SBE are uncommon, but are more frequent in longer procedures.

Endoscopist-directed propofol: pros and cons

Concerns about the safety of endoscopist-directed propofol (EDP) have been voiced that propofol should be given only by healthcare professionals trained in the administration of general anesthesia. Here we discuss the safety and drawbacks of EDP for routine endoscopic procedures. Currently, both diagnostic and therapeutic endoscopy are well tolerated and accepted by both patients and endoscopists due to the application of sedation in most clinics worldwide. Accordingly, propofol use is increasing in many countries. It is crucial for endoscopists to be very familiar with the use of propofol or a combination of drugs. However, the controversy regarding the administration of sedation by an endoscopist or an anesthesiologist continues. Until now, there have been no randomized control trials comparing sedation induced by propofol administered by an endoscopist or by an anesthesiologist. It might be difficult to perform this kind of study. For the convenience and safety of sedative endoscopy, it would be important that EDP be generally applied to endoscopic procedures, and for more safety, an anesthesiologist may automatically take care of particular patients at high risk of suffering from propofol side effects.

Risk of sedation for diagnostic esophagogastroduodenoscopy in obstructive sleep apnea patients

AIM

To investigate whether patients with obstructive sleep apnea (OSA) are at risk of sedation-related complications during diagnostic esophagogastroduodenoscopy (EGD).

METHODS

A prospective study was performed in consecutive patients with OSA, who were confirmed with full-night polysomnography between July 2010 and April 2011. The occurrence of cardiopulmonary complications related to sedation during diagnostic EGD was compared between OSA and control groups.

RESULTS

During the study period, 31 patients with OSA and 65 controls were enrolled. Compared with the control group, a higher dosage of midazolam was administered (P = 0.000) and a higher proportion of deep sedation was performed (P = 0.024) in the OSA group. However, all adverse events, including sedation failure, paradoxical responses, snoring or apnea, hypoxia, hypotension, oxygen or flumazenil administration, and other adverse events were not different between the two groups (all P > 0.1). Patients with OSA were not predisposed to hypoxia with multivariate logistic regression analysis (P = 0.068).

CONCLUSION

In patients with OSA, this limited sized study did not disclose an increased risk of cardiopulmonary complications during diagnostic EGD under sedation.

Preparation and patient evaluation for safe gastrointestinal endoscopy

Patient evaluation and preparation is the first and mandatory step to ensure safety and quality of endoscopic procedures. This begins and ends with identifying the patient, procedure type, and indication. Every patient has the right to be fully informed about risks and benefits of what is to be performed on them, and the medical personnel should respect the decision made by the patients. Thoroughly performed history taking and physical examination will guide the endoscopists to better stratify risk and plan sedation. Special attention should be given to higher-risk patients with higher-risk condition undergoing higher-risk procedures. Making preparations to monitor the patients and being ready to handle emergency situations throughout the endoscopic procedure are sine qua non to warrant safe endoscopy.

Is the American Society of Anesthesiologists classification useful in risk stratification for endoscopic procedures?

BACKGROUND

The American Society of Anesthesiologists (ASA) physical status classification is a measurement of comorbidity and a predictor of perioperative morbidity and mortality.

OBJECTIVE

To assess the predictive ability of the ASA class for periendoscopic adverse events.

DESIGN

Retrospective cohort analysis.

SETTING

A total of 74 sites in the United States comprising academic, community/health maintenance organization, and Veterans Affairs/military practices affiliated with the Clinical Outcomes Research Initiative (CORI) database.

PATIENTS

Patients who were 18 years or older who underwent an endoscopic procedure between 2000 and 2008.

INTERVENTIONS

EGD, colonoscopy, flexible sigmoidoscopy, and ERCP.

MAIN OUTCOME MEASUREMENTS

Immediate adverse event requiring an unplanned intervention.

RESULTS

A total of 1,590,648 endoscopic procedures were performed on 1,318,495 individual patients. The majority of patients were designated as ASA class I or II (I: 27%, II: 63%). An immediate adverse event occurred in 0.35% of all endoscopic procedures (n = 5596) and was proportionally highest for ERCPs (1.84%). Increasing ASA class was associated with higher prevalence and a stepwise increase in the odds ratio of serious adverse events for EGD (II: 1.54 [95% confidence interval (CI), 1.31-1.82]; III: 3.90 [95% CI, 3.27-4.64]; IV/V: 12.02 [95% CI, 9.62-15.01]); and colonoscopy (II: 0.92 [95% CI, 0.85-1.01]; III: 1.66 [95% CI, 1.46-1.87]; IV/V: 4.93 [95% CI, 3.66-66.3]). This trend was not significant for flexible sigmoidoscopy and ERCP.

LIMITATIONS

Retrospective; endpoint was a surrogate for periprocedure morbidity.

CONCLUSIONS

ASA class is associated with increased risk of adverse events at endoscopy, particularly for EGD and colonoscopy. It is useful in endoscopic risk stratification and an important quality indicator for endoscopy.

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.

Prospective description of coughing, hemodynamic changes, and oxygen desaturation during endoscopic sedation

BACKGROUND

Deep sedation is increasingly used for endoscopy. The impact of sedation level on hemodynamic status, oxygenation, and aspiration risk is incompletely described.

AIMS

To describe the incidence of intraprocedural cough, hemodynamic changes, oxygen desaturation, and their relationship to clinical factors and sedation level.

METHODS

Detailed prospective recordings of hemodynamic changes, oxygen desaturation, and cough during 757 nonemergent endoscopic procedures done under sedation using propofol, midazolam, and/or fentanyl.

RESULTS

Thirteen percent of patients had at least one cough and 3% had prolonged cough. Cough was more common in nonsmokers (P = 0.05), upper endoscopy (P < 0.0001), with propofol (P = 0.0008), longer procedures (P = 0.0001), and hiccups (P = 0.01). The association between supine positioning during colonoscopy and cough approached significance (P = 0.06). Oxygen desaturation was rare (4%) and associated only with deep sedation (P = 0.02). Mean systolic and diastolic blood pressure (BP) dropped by 7.3 and 5.6% respectively. Decreases in systolic BP were more common in whites (P = 0.03), males (P = 0.004), nonsmokers (P = 0.04), during colonoscopy (P < 0.0001), and in patients receiving midazolam and fentanyl (P = 0.01). Heart rate (HR) dropped >20% from baseline in 15% of patients and was more common during colonoscopy (P = 0.002). HR increased >20% in 20% of patients and was more common with coughing (P < 0.0001) and in younger patients (P = 0.0002). No patient required pharmacologic treatment of BP or HR.

CONCLUSIONS

We have described procedural predictors of cough that may help clinicians reduce the risk of aspiration during endoscopy. Hemodynamic changes during endoscopy are common but largely clinically insignificant.

Pre-existing diseases of patients increase susceptibility to hypoxemia during gastrointestinal endoscopy

Hypoxemia is the most common adverse event that happened during gastrointestinal endoscopy. To estimate risk of hypoxemia prior to endoscopy, American Society of Anesthesiology (ASA) classification scores were used as a major predictive factor. But the accuracy of ASA scores for predicting hypoxemia incidence was doubted here, considering that the classification system ignores much information about general health status and fitness of patient that may contribute to hypoxemia. In this retrospective review of clinical data collected prospectively, the data on 4904 procedures were analyzed. The Pearson’s chi-square test or the Fisher exact test was employed to analyze variance of categorical factors. Continuous variables were statistically evaluated using t-tests or Analysis of variance (ANOVA). As a result, only 245 (5.0%) of the enrolled 4904 patients were found to present hypoxemia during endoscopy. Multivariable logistic regressions revealed that independent risk factors for hypoxemia include high BMI (BMI 30 versus 20, Odd ratio: 1.52, 95% CI: 1.13–2.05; P = 0.0098), hypertension (Odd ratio: 2.28, 95% CI: 1.44–3.60; P = 0.0004), diabetes (Odd ratio: 2.37, 95% CI: 1.30–4.34; P = 0.005), gastrointestinal diseases (Odd ratio: 1.77, 95% CI: 1.21–2.60; P = 0.0033), heart diseases (Odd ratio: 1.97, 95% CI: 1.06–3.68; P = 0.0325) and the procedures that combined esophagogastroduodenoscopy (EGD) and colonoscopy (Odd ratio: 4.84, 95% CI: 1.61–15.51; P = 0.0292; EGD as reference). It is noteworthy that ASA classification scores were not included as an independent predictive factor, and susceptibility of youth to hypoxemia during endoscopy was as high as old subjects. In conclusion, some certain pre-existing diseases of patients were newly identified as independent risk factors for hypoxemia during GI endoscopy. High ASA scores are a confounding predictive factor of pre-existing diseases. We thus recommend that youth (≤18 yrs), obese patients and those patients with hypertension, diabetes, heart diseases, or GI diseases should be monitored closely during sedation endoscopy.

Development of an Automatic Adjustable Colonoscope

Colonoscopy can be associated with many problems, such as mechanical trauma due to the distal tip contacting the colon wall or health issues due to the extended use of anesthesia. In order to eliminate these complications, an automatic adjustable colonoscope was designed. This device uses sensors, actuators, and a control system to automatically position the distal tip in the center of the colon lumen. The sensors were tested to determine their ability to accurately sense the distance from the tip to the surface. The actuators were tested to determine the correlation between motor rotation and displacement of the distal tip. The control system was tested to assess the ability of the device to position the tip in the center of the test tube and the ability to navigate through a flat test course. It was determined that the sensors could accurately determine distances from 0 to 15 mm from the test surface in all test conditions. The motors for up-down movement and left-right movement of the colonoscope had response times of 0.57 s and 0.69 s, respectively, when the motors were rotated from 0 deg to 90 deg. The control system was able to safely move the colonoscope tip away from all walls of the test apparatus. It was also able to navigate through the flat test course without coming in contact with the walls. The automatic adjustable colonoscope has demonstrated that it can safely and effectively position the distal tip to avoid contact with the walls of the test surface.

[An established anesthesia team-care model: over 12000 cases in a digestive endoscopy unit]

BACKGROUND AND OBJECTIVE

The growing demand for digestive and other endoscopic procedures outside the operating room, both in terms of type of endoscopy and number of patients, requires reorganization of the anesthesiology department's workload. We describe 2 years of our hospital digestive endoscopy unit's experience with a now well-established care model involving both anesthesiologists and nurse anesthetists.

MATERIAL AND METHODS

After previously reviewing the medical records of outpatients and conducting a telephone interview about state of health, nurse anesthetists administered a combination of propofol and remifentanil through a target-controlled infusion system under an anesthesiologist's direct supervision.

RESULTS

The ratio of anesthesiologists to nurses ranged from 1:2 to 1:3 according to the complexity of the examination procedure. Over 12000 endoscopies (simple to advanced) in a total of 11853 patients were performed under anesthesia during the study period. Airway management maneuvers were required by 4.9% of the patients; 0.18% required bag ventilation for respiratory depression, and 0.084% required bolus doses of a vasopressor to treat hypotension or atropine to treat bradycardia. The procedure had to be halted early in 9 patients (0.07%). No patient required orotracheal intubation and none died. Nor were any complications related to sedation recorded.

CONCLUSION

The results suggest that this care model can safely accommodate a large caseload in anesthesia at an optimum level of quality.

Sedation in digestive endoscopy: the Athens international position statements

BACKGROUND

Guidelines and practice standards for sedation in endoscopy have been developed by various national professional societies. No attempt has been made to assess consensus among internationally recognized experts in this field.

AIM

To identify areas of consensus and dissent among international experts on a broad range of issues pertaining to the practice of sedation in digestive endoscopy.

METHODS

Thirty-two position statements were reviewed during a 1 (1/2)-day meeting. Thirty-two individuals from 12 countries and four continents, representing the fields of gastroenterology, anaesthesiology and medical jurisprudence heard evidence-based presentations on each statement. Level of agreement among the experts for each statement was determined by an open poll.

RESULTS

The principle recommendations included the following: (i) sedation improves patient tolerance and compliance for endoscopy, (ii) whenever possible, patients undergoing endoscopy should be offered the option of having the procedure either with or without sedation, (iii) monitoring of vital signs as well as the levels of consciousness and pain/discomfort should be performed routinely during endoscopy, and (iv) endoscopists and nurses with appropriate training can safely and effectively administer propofol to low-risk patients undergoing endoscopic procedures.

CONCLUSIONS

While the standards of practice vary from country to country, there was broad agreement among participants regarding most issues pertaining to sedation during endoscopy.

Office based--is my anesthetic care any different? Assessment and management

Office-based anesthesia (OBA) is a unique and challenging venue, and, although the clinical outcomes have not been evaluated extensively, existing data indicate a need for increased regulation and additional education. Outcomes in OBA can be improved by education not only of anesthesiologists but also of surgeons, proceduralists, and nursing staff. Legislators must be educated so that appropriate regulations are instituted governing the practice of office-based surgery and the lay public must be educated to make wise, informed decisions about choice of surgery location. The leadership of societies, along with support from the membership, must play a key role in this educational process; only then can OBA become as safe as the anesthesia care in traditional venues.

Endoscopist-directed administration of propofol: a worldwide safety experience

BACKGROUND & AIMS

Endoscopist-directed propofol sedation (EDP) remains controversial. We sought to update the safety experience of EDP and estimate the cost of using anesthesia specialists for endoscopic sedation.

METHODS

We reviewed all published work using EDP. We contacted all endoscopists performing EDP for endoscopy that we were aware of to obtain their safety experience. These complications were available in all patients: endotracheal intubations, permanent neurologic injuries, and death.

RESULTS

A total of 646,080 (223,656 published and 422,424 unpublished) EDP cases were identified. Endotracheal intubations, permanent neurologic injuries, and deaths were 11, 0, and 4, respectively. Deaths occurred in 2 patients with pancreatic cancer, a severely handicapped patient with mental retardation, and a patient with severe cardiomyopathy. The overall number of cases requiring mask ventilation was 489 (0.1%) of 569,220 cases with data available. For sites specifying mask ventilation risk by procedure type, 185 (0.1%) of 185,245 patients and 20 (0.01%) of 142,863 patients required mask ventilation during their esophagogastroduodenoscopy or colonoscopy, respectively (P < .001). The estimated cost per life-year saved to substitute anesthesia specialists in these cases, assuming they would have prevented all deaths, was $5.3 million.

CONCLUSIONS

EDP thus far has a lower mortality rate than that in published data on endoscopist-delivered benzodiazepines and opioids and a comparable rate to that in published data on general anesthesia by anesthesiologists. In the cases described here, use of anesthesia specialists to deliver propofol would have had high costs relative to any potential benefit.

Anesthesia for gastrointestinal endoscopic procedures

Traditionally, sedation for gastrointestinal endoscopic procedures was provided by the gastroenterologist. Increasingly, however, complex procedures are being performed on seriously ill patients. As a result, anesthesiologists now are providing anesthesia and sedation in the gastrointestinal endoscopy suite for many of these patients. This article reviews the challenges encountered in this environment and anesthetic techniques that can be used successfully for these procedures.