Capnographic Monitoring in Routine EGD and Colonoscopy With Moderate Sedation: A Prospective, Randomized, Controlled Trial

Continuous Capnography for Early Detection of Respiratory Compromise During Gastroenterological Procedural Sedation and Analgesia

Gastroenterology nurses working across a variety of clinical settings are responsible for periprocedural monitoring during moderate to deep procedural sedation and analgesia (PSA) to identify signs of respiratory compromise and intervene to prevent cardiorespiratory events. Pulse oximetry is the standard of care for respiratory monitoring, but it may delay or fail to detect abnormal ventilation during PSA. Continuous capnography, which measures end-tidal CO2 as a marker of alveolar ventilation, has been endorsed by a number of clinical guidelines. Large clinical trials have demonstrated that the addition of continuous capnography to pulse oximetry during PSA for various gastroenterological procedures reduces the incidence of hypoxemia, severe hypoxemia, and apnea. Studies have shown that the cost of adding continuous capnography is offset by the reduction in adverse events and hospital length of stay. In the postanesthesia care unit, continuous capnography is being evaluated for monitoring opioid-induced respiratory depression and to guide artificial airway removal. Studies are also examining the utility of continuous capnography to predict the risk of opioid-induced respiratory depression among patients receiving opioids for primary analgesia. Continuous capnography monitoring has become an essential tool to detect early signs of respiratory compromise in patients receiving PSA during gastroenterological procedures. When combined with pulse oximetry, it can help reduce cardiorespiratory adverse events, improve patient outcomes and safety, and reduce health care costs.

Thoracic impedance pneumography in propofol-sedated patients undergoing percutaneous endoscopic gastrostomy (PEG) placement in gastrointestinal endoscopy: A prospective, randomized trial

STUDY OBJECTIVE

To assess the efficacy of an ECG-based method called thoracic impedance pneumography to reduce hypoxic events in endoscopy.

DESIGN

This was a single center, 1:1 randomized controlled trial.

SETTING

The trial was conducted during the placement of percutaneous endoscopic gastrostomy (PEG).

PATIENTS

173 patients who underwent PEG placement were enrolled in the present trial. Indication was oncological in most patients (89%). 58% of patients were ASA class II and 42% of patients ASA class III.

INTERVENTIONS

Patients were randomized in the standard monitoring group (SM) with pulse oximetry and automatic blood pressure measurement or in the intervention group with additional thoracic impedance pneumography (TIM). Sedation was performed with propofol by gastroenterologists or trained nurses.

MEASUREMENTS

Hypoxic episodes defined as SpO2 < 90% for >15 s were the primary endpoint. Secondary endpoints were minimal SpO2, apnea >10s/>30s and incurred costs.

MAIN RESULTS

Additional use of thoracic impedance pneumography reduced hypoxic episodes (TIM: 31% vs SM: 49%; p = 0.016; OR 0.47; NNT 5.6) and elevated minimal SpO2 per procedure (TIM: 90.0% ± 8.9; SM: 84.0% ± 17.6; p = 0.007) significantly. Apnea events >10s and > 30s were significantly more often detected in TIM (43%; 7%) compared to SM (1%; 0%; p < 0.001; p = 0.014) resulting in a time advantage of 17 s before the occurrence of hypoxic events. As a result, adjustments of oxygen flow were significantly more often necessary in SM than in TIM (p = 0.034) and assisted ventilation was less often needed in TIM (2%) compared with SM (9%; p = 0.053). Calculated costs for the additional use of thoracic impedance pneumography were 0.13$ (0.12 €/0.11 £) per procedure.

CONCLUSIONS

Additional thoracic impedance pneumography reduced the quantity and extent of hypoxic events with less need of assisted ventilation. Supplemental costs per procedure were negligible.

KEY WORDS

thoracic impedance pneumography, capnography, sedation, monitoring, gastrointestinal endoscopy, percutaneous endoscopic gastrostomy.

Korean clinical practice guidelines for diagnostic and procedural sedation

Safe and effective sedation depends on various factors, such as the choice of sedatives, sedation techniques used, experience of the sedation provider, degree of sedation-related education and training, equipment and healthcare worker availability, the patient's underlying diseases, and the procedure being performed. The purpose of these evidence-based multidisciplinary clinical practice guidelines is to ensure the safety and efficacy of sedation, thereby contributing to patient safety and ultimately improving public health. These clinical practice guidelines comprise 15 key questions covering various topics related to the following: the sedation providers; medications and equipment available; appropriate patient selection; anesthesiologist referrals for high-risk patients; pre-sedation fasting; comparison of representative drugs used in adult and pediatric patients; respiratory system, cardiovascular system, and sedation depth monitoring during sedation; management of respiratory complications during pediatric sedation; and discharge criteria. The recommendations in these clinical practice guidelines were systematically developed to assist providers and patients in sedation-related decision making for diagnostic and therapeutic examinations or procedures. Depending on the characteristics of primary, secondary, and tertiary care institutions as well as the clinical needs and limitations, sedation providers at each medical institution may choose to apply the recommendations as they are, modify them appropriately, or reject them completely.

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.

The effect of capnography on the incidence of hypoxia during sedation for EGD and colonoscopy in mildly obese patients: a randomized, controlled study

BACKGROUND

By continually monitoring end-tidal carbon dioxide concentrations, capnography can detect abnormal ventilation or apnoea early. This randomized, controlled study explored the effect of early intervention with capnography on the incidence of hypoxia in mildly obese patients undergoing sedation for esophagogastroduodenoscopy (EGD) and colonoscopy.

METHODS

This is a single-center, randomized, single-blind, parallel-assignment, controlled trial. Mildly obese patients (28 kg/m² ≤ BMI < 40 kg/m²) undergoing sedation for EGD and colonoscopy were randomly assigned to either the standard or capnography group. Standard cardiopulmonary monitoring equipment was used in both groups, and additional capnography was performed in the capnography group. In the event of inadequate alveolar ventilation during sedation, five interventions were administered in sequence (a-e) : a: increasing oxygen flow (5 L/min); b: a chin lift or jaw thrust maneuver; c: placement of the nasopharyngeal airway and chin lift; d: mask positive-pressure ventilation, and e: ventilator-assisted ventilation with tube insertion. The primary outcome was the incidence of hypoxia (SpO₂ < 90%, ≥ 10 s) in each group. The secondary outcomes included the incidence of severe hypoxia (SpO₂ ≤ 85%), subclinical respiratory depression (90% ≤ SpO₂ < 95%), interventions, minimum SpO₂ during operation, patient satisfaction, endoscopist satisfaction, and other adverse events of anesthesia sedation.

RESULTS

228 patients were included (capnography group = 112; standard group = 113; three patients were excluded) in this study. The incidence of hypoxia was significantly lower in the capnography group than in the standard group (13.4% vs. 30.1%, P = 0.002). Subclinical respiratory depression in the capnography group was higher than that of the standard group (30.4% vs. 17.7%, P = 0.026). There was only a 5.4% incidence of severe hypoxia in the capnography group compared with 14.2% in the standard group (P = 0.026). During sedation, 96 and 34 individuals in the capnography and standard groups, respectively, underwent the intervention. There was a statistically significant difference (P < 0.0001) in the number of the last intraoperative intervention between the two groups ( a:47 vs. 1, b:46 vs. 26, c:2 vs. 5, d:1 vs. 2, e:0 vs. 0 ). No significant differences were found between the two groups in terms of minimum SpO₂ during operation, patient satisfaction, or endoscopist satisfaction rating. There was no statistically significant difference in adverse events of anesthesia sedation between the two groups.

CONCLUSION

Capnography during sedation for EGD and colonoscopy allows for the detection of apnea and altered breathing patterns in mildly obese patients before SpO₂ is reduced. Effective intervention measures are given to patients within this time frame, which reduces the incidence of hypoxia and severe hypoxia in patients.

TRIAL REGISTRATION

Ethical approval was granted by the Medical Ethics Committee (Chairperson Professor Tian Hui) of Qilu Hospital, Shandong University ((Ke) Lun Audit 2021 (186)) on 15/07/2021. The study was registered ( https://www.chictr.org.cn ) on 23/10/2021(ChiCTR2100052234). Designed and reported using CONSORT statements.

Study on different sequences of painless gastroenteroscopy in patients with difficult airway

The selection of different examination sequences of painless gastroscopy in patients with difficult airway risk was explored in this study. A total of 45 patients undergoing painless gastroscopy with Mallampati airway score of III-IV were randomly assigned into two groups (A group and B group) according to the sequence of colonoscopy and gastroscopy. Group A was first examined by gastroscopy after anesthesia, and then by colonoscopy. Group B was examined in the opposite order, first by colonoscopy, and then by gastroscopy. Ramsay Sedation scores were evaluated every five minutes when gastroscopy was performed in the two groups. The dosage of propofol, blood pressure, heart rate, blood oxygen saturation, recovery time, hospital leaving time, and adverse reactions after induction and endoscopy were recorded. The dosage of propofol and change of vital signs in B group was less than that in A group. Operation time, recovery time, hospital leaving time and postoperative adverse reactions have no significant difference between two groups. For patients at risk of difficult airway, colonoscopy followed by gastroscopy has more stable intraoperative vital signs and less propofol consumption.

Phase II study comparing nasal pressure monitoring with capnography during invasive endoscopic procedures: a single-center, single-arm trial

Nasal pressure signal is commonly used to evaluate obstructive sleep apnea. This study aimed to assess its safety for respiratory monitoring during sedation. A total of 45 adult patients undergoing sedation with propofol and fentanyl for invasive endoscopic procedures were enrolled. While both nasal pressure and capnograph signals were continuously recorded, only the nasal pressure signal was displayed. The primary outcome was the incidence of oxygen desaturation below 90%. The secondary outcomes were the ability to predict the desaturation and incidence of harmful events and false alarms, defined as an apnea waveform lasting more than 3 min without desaturation. Of the 45 participants, 43 completed the study. At least one desaturation event occurred in 12 patients (27.9%; 95% confidence interval 15.3-43.7%). In these 12 patients, more than half of the desaturation events were predictable in 9 patients by capnography and 11 patients by nasal pressure monitoring (p = 0.59). In the 43 patients, false alarms were detected in 7 patients with capnography and 11 patients with nasal pressure monitoring (p = 0.427). Harmful events unrelated to nasal pressure monitoring occurred in 2 patients. Nasal pressure monitoring is safe and possibly useful for respiratory monitoring despite false alarms during sedation.

Efficacy of capnographic and bispectral index monitoring on trans-oral therapeutic endoscopy: A prospective observational study

BACKGROUND AND AIM

Oral therapeutic and invasive endoscopy requires deep sedation to reduce patient distress due to prolonged examination and procedures. The usefulness of capnography and bispectral index (BIS) monitoring in the early hypoxia detection in oral therapeutic and invasive endoscopy has yet to be evaluated. This study aimed to investigate the clinical impact of capnography and BIS monitoring on hypoxic events during oral therapeutic and invasive endoscopic procedures.

METHODS

This is a prospective observational study. Trans-oral non-intubated therapeutic and/or invasive endoscopic procedures were performed with conventional monitoring (pulse oximetry, pulse, and blood pressure) as well as additional monitoring (BIS and end-tidal CO₂ concentration). Hypoxia is defined as oxygen saturation of <90% that lasts >15 s. The clinical impact of capnography and BIS monitoring on hypoxic events during oral therapeutic and invasive endoscopic procedures were investigated with the risk factors for hypoxia in each patient.

RESULTS

Patients with hypoxia had significantly more apneas detected using capnography than other patients. The multivariate analysis revealed the detected apnea by capnography as an independent risk factor for hypoxia (odds ratio: 3.48[95% confidence interval: 1.24-9.78], P = 0.02). The BIS was not significantly different as a risk factor for hypoxia; however, per-event analysis revealed significantly decreased BIS values over time in 3 min before hypoxic events.

CONCLUSIONS

Apnea detected by capnography was an independent predictor of hypoxia. The BIS value was not associated with hypoxia events; however, it showed a significant downward trend before hypoxia events.

Capnography for Monitoring of the Critically Ill Patient

Capnography has been widely adopted in multiple clinical areas. The capnogram and end-tidal carbon dioxide offer a wealth of information, in the right clinical setting, and when properly interpreted. In this article, the authors aim to review the most common clinical scenarios during which capnography has been shown to be of benefit. This includes the areas of fluid responsiveness, cardiopulmonary resuscitation, and conscious sedation. They review the published literature, highlighting its pitfalls and identifying its limitations.

Prevention of pulmonary complications in sedated patients undergoing interventional procedures in the nonoperating room anesthesia setting

PURPOSE OF REVIEW

Nonoperating room anesthesia (NORA) procedures have expanded in number, variety, and complexity. NORA involves all age groups, including frail older adults and patients often considered too sick to tolerate traditional surgical interventions. Postoperative pulmonary complications are a significant source of adverse events in the perioperative setting. We present a review focused on preventing pulmonary complications in the interventional NORA setting.

RECENT FINDINGS

NORA locations should function as independent, autonomous ambulatory units. We discuss a strategic plan involving a thorough preoperative evaluation of patients, including recognizing high-risk patients and their anesthetic management. Finally, we offer guidance on the challenges of conducting sedation and anesthesia in patients with coronavirus disease 2019 (COVID-19) or a history of COVID-19.

SUMMARY

The demands on the interventional NORA anesthesia team are increasing. Strategic planning, checklists, consistent staffing assignments, and scheduled safety drills are valuable tools to improve patient safety. In addition, through quality improvement initiatives and reporting, NORA anesthetists can achieve reductions in periprocedural pulmonary complications.

Pre-procedural Preparation and Sedation for Gastrointestinal Endoscopy in Patients with Advanced Liver Disease

Gastrointestinal endoscopy in patients with advanced liver disease poses various challenges, a major one being procedural sedation and its associated considerations. While sedation during endoscopy can improve patient comfort, decrease anxiety, and facilitate procedural completion, in patients with advanced liver disease, it is also associated with substantial and unique risks due to alterations in drug metabolism and other factors. As such, the choice of sedative agent(s) and related logistics may require careful inter-disciplinary planning and individualized considerations. Furthermore, a large proportion of agents require dose reductions and particular monitoring of the vital signs, level of consciousness, and other indices. In the present review, we provide a contemporary overview of procedural sedation considerations, commonly used intravenous sedatives, and second-line as well as novel sedatives for gastrointestinal endoscopy in patients with advanced liver disease.

Efficacy and Safety of Deep Sedation and Anaesthesia for Complex Endoscopic Procedures—A Narrative Review

Propofol sedation for advanced endoscopic procedures is a widespread technique at present, which generates controversy worldwide when anaesthetic or non-anaesthetic personnel administer this form of sedation. There is some evidence for safe administered propofol sedation by non-anaesthetic personnel in patients undergoing endoscopy procedures, but there are only few randomised trials addressing the safety and efficacy of propofol in patients undergoing advanced procedures. A serious possible consequence of propofol sedation is the rapid and unpredictable progression from deep sedation to general anaesthesia mostly when elderly and frail patients are involved in the diagnosis or treatment of various neoplasia. This situation requires rescue measures with skilled airway management. The aim of this paper is to review the safety and efficacy aspects of sedation techniques, with special reference to propofol administration covering the whole patient journey, including preassessment, sedation options and discharge when advanced endoscopic procedures are performed.

Transient End-Tidal Carbon Dioxide Elevation During Pediatric Upper Endoscopy With Carbon Dioxide Insufflation: Is It True Hypercapnia?

BACKGROUND

Endoscopic insufflation, long performed using air, is being replaced by carbon dioxide (CO2) at many pediatric centers, despite limited published data on its use in children. We have previously demonstrated that CO2 use during esophagogastroduodenoscopy (EGD) in non-intubated children is associated with transient elevations of end-tidal CO2 (EtCO2). This observation raised concerns about possible CO2 inhalation and systemic absorption. Here, we investigate this concern by concurrently measuring both EtCO2 and transcutaneous CO2 (tCO2) during upper endoscopic procedures in children.

AIM

To determine if elevations in EtCO2 levels seen in non-intubated children undergoing CO2 insufflation during EGD are associated with elevated systemic CO2 levels.

METHODS

Double-blinded, prospective, randomized clinical trial. Children were randomized 1:1 to receive either CO2 or air for endoscopic insufflation. EtCO2 was sampled with a CO2-sampling nasal cannula and tCO2 was monitored using the Radiometer transcutaneous monitoring device.

RESULTS

Fifty nine patients were enrolled; 30 patients in the CO2 insufflation group and 29 in the air group. All patients underwent a procedure involving an EGD. Transient elevations in EtCO2 (defined as >60 mmHg) were observed only in the CO2 insufflation group. This contrasted with the similar elevations of tCO2 between the CO2 and air insufflation groups. None of these events were of clinically significant magnitude or duration.

CONCLUSION

This study demonstrates that the observed transient elevations in EtCO2 seen during EGD in non-intubated children receiving CO2 insufflation are most likely measurements of eructated CO2 without evidence of excessive systemic absorption of CO2.

Evaluation of the Integrated Pulmonary Index® during non-anesthesiologist sedation for percutaneous endoscopic gastrostomy

Standard monitoring of heart rate, blood pressure and arterial oxygen saturation during endoscopy is recommended by current guidelines on procedural sedation. A number of studies indicated a reduction of hypoxic (art. oxygenation < 90% for > 15 s) and severe hypoxic events (art. oxygenation < 85%) by additional use of capnography. Therefore, U.S. and the European guidelines comment that additional capnography monitoring can be considered in long or deep sedation. Integrated Pulmonary Index® (IPI) is an algorithm-based monitoring parameter that combines oxygenation measured by pulse oximetry (art. oxygenation, heart rate) and ventilation measured by capnography (respiratory rate, apnea > 10 s, partial pressure of end-tidal carbon dioxide [PetCO2]). The aim of this paper was to analyze the value of IPI as parameter to monitor the respiratory status in patients receiving propofol sedation during PEG-procedure. Patients reporting for PEG-placement under sedation were randomized 1:1 in either standard monitoring group (SM) or capnography monitoring group including IPI (IM). Heart rate, blood pressure and arterial oxygen saturation were monitored in SM. In IM additional monitoring was performed measuring PetCO2, respiratory rate and IPI. Capnography and IPI values were recorded for all patients but were only visible to the endoscopic team for the IM-group. IPI values range between 1 and 10 (10 = normal; 8-9 = within normal range; 7 = close to normal range, requires attention; 5-6 = requires attention and may require intervention; 3-4 = requires intervention; 1-2 requires immediate intervention). Results on capnography versus standard monitoring of the same study population was published previously. A total of 147 patients (74 in SM and 73 in IM) were included in the present study. Hypoxic events occurred in 62 patients (42%) and severe hypoxic events in 44 patients (29%), respectively. Baseline characteristics were equally distributed in both groups. IPI = 1, IPI < 7 as well as the parameters PetCO2 = 0 mmHg and apnea > 10 s had a high sensitivity for hypoxic and severe hypoxic events, respectively (IPI = 1: 81%/81% [hypoxic/severe hypoxic event], IPI < 7: 82%/88%, PetCO2: 69%/68%, apnea > 10 s: 84%/84%). All four parameters had a low specificity for both hypoxic and severe hypoxic events (IPI = 1: 13%/12%, IPI < 7: 7%/7%, PetCO2: 29%/27%, apnea > 10 s: 7%/7%). In multivariate analysis, only SM and PetCO2 = 0 mmHg were independent risk factors for hypoxia. IPI (IPI = 1 and IPI < 7) as well as the individual parameters PetCO2 = 0 mmHg and apnea > 10 s allow a fast and convenient conclusion on patients' respiratory status in a morbid patient population. Sensitivity is good for most parameters, but specificity is poor. In conclusion, IPI can be a useful metric to assess respiratory status during propofol-sedation in PEG-placement. However, IPI was not superior to PetCO2 and apnea > 10 s.

Guidelines on analgosedation, monitoring, and recovery time for flexible bronchoscopy: a systematic review

BACKGROUND

Patients undergoing bronchoscopy in spontaneous breathing are prone to hypoxaemia and hypercapnia. Sedation, airway obstruction, and lung diseases impair respiration and gas exchange. The restitution of normal respiration takes place in the recovery room. Nonetheless, there is no evidence on the necessary observation time. We systematically reviewed current guidelines on bronchoscopy regarding sedation, monitoring and recovery.

METHODS

This review was registered at the PROSPERO database (CRD42020197476). MEDLINE and awmf.org were double-searched for official guidelines, recommendation or consensus statements on bronchoscopy from 2010 to 2020. The PICO-process focussed on adults (Patients), bronchoscopy with maintained spontaneous breathing (Interventions), and recommendations regarding the intra- and postprocedural monitoring and sedation (O). The guideline quality was graded. A catalogue of 54 questions was answered. Strength of recommendation and evidence levels were recorded for each recommendation.

RESULTS

Six guidelines on general bronchoscopy and three expert statements on special bronchoscopic procedures were identified. Four guidelines were evidence-based. Most guidelines recommend sedation to improve the patient's tolerance. Midazolam combined with an opioid is preferred. The standard monitoring consists of non-invasive blood pressure, and pulse oximetry, furthermore electrocardiogram in cardiac patients. Only one guideline discusses hypercapnia and capnometry, but without consensus. Two guidelines discuss a recovery time of two hours, but a recommendation was not given because of lack of evidence.

CONCLUSION

Evidence for most issues is low to moderate. Lung-diseased patients are not represented by current guidelines. Capnometry and recovery time lack evidence. More primary research in these fields is needed so that future guidelines may address these issues, too.

Guidelines for accreditation of endoscopy units: quality measures from the Korean Society of Coloproctology

Purpose

Colonoscopy is an effective method of screening for colorectal cancer (CRC), and it can prevent CRC by detection and removal of precancerous lesions. The most important considerations when performing colonoscopy screening are the safety and satisfaction of the patient and the diagnostic accuracy. Accordingly, the Korean Society of Coloproctology (KSCP) herein proposes an optimal level of standard performance to be used in endoscopy units and by individual colonoscopists for screening colonoscopy. These guidelines establish specific criteria for assessment of safety and quality in screening colonoscopy.

Methods

The Colonoscopy Committee of the KSCP commissioned this Position Statement. Expert gastrointestinal surgeons representing the KSCP reviewed the published evidence to identify acceptable quality indicators and indicators that lacked sufficient evidence.

Results

The KSCP recommends an optimal standard list for quality control of screening colonoscopy in the following 6 categories: training and competency of the colonoscopist, procedural quality, facilities and equipment, performance indicators and auditable outcomes, disinfection of equipment, and sedation and recovery of the patient.

Conclusion

The KSCP recommends that endoscopy units performing CRC screening evaluate 6 key performance measures during daily practice.

Guidelines for sedation in gastroenterological endoscopy (second edition)

Sedation in gastroenterological endoscopy has become an important medical option in routine clinical care. Here, the Japan Gastroenterological Endoscopy Society and the Japanese Society of Anesthesiologists together provide the revised "Guidelines for sedation in gastroenterological endoscopy" as a second edition to address on-site clinical questions and issues raised for safe examination and treatment using sedated endoscopy. Twenty clinical questions were determined and the strength of recommendation and evidence quality (strength) were expressed according to the "MINDS Manual for Guideline Development 2017." We were able to release up-to-date statements related to clinical questions and current issues relevant to sedation in gastroenterological endoscopy (henceforth, "endoscopy"). There are few reports from Japan in this field (e.g., meta-analyses), and many aspects have been based only on a specialist consensus. In the current scenario, benzodiazepine drugs primarily used for sedation during gastroenterological endoscopy are not approved by national health insurance in Japan, and investigations regarding expense-related disadvantages have not been conducted. Furthermore, including the perspective of beneficiaries (i.e., patients and citizens) during the creation of clinical guidelines should be considered. These guidelines are standardized based on up-to-date evidence quality (strength) and supports on-site clinical decision-making by patients and medical staff. Therefore, these guidelines need to be flexible with regard to the wishes, age, complications, and social conditions of the patient, as well as the conditions of the facility and discretion of the physician.

Effects of transcutaneous electrical acupuncture point stimulation on peripheral capillary oxygen saturation in elderly patients undergoing colonoscopy with sedation: a prospective randomized controlled trial

INTRODUCTION

This study investigated whether transcutaneous electrical acupuncture point stimulation (TEAS) at PC6 can reduce the proportion of elderly patients experiencing a drop of ⩾4% in peripheral capillary oxygen saturation (SpO₂) while undergoing colonoscopy under sedation.

METHODS

A total of 32 elderly patients (aged ⩾ 65 years) scheduled for colonoscopy were randomly assigned in a 1:1 ratio to receive either real or sham TEAS (treatment or control groups, respectively). Each patient received oxygen (2 L/min) delivered routinely via nasal cannula. The treatment group was given TEAS at PC6 for 20 min at 2 Hz frequency and 6 mA intensity; the control group underwent the same procedures but with zero frequency/intensity. SpO₂ and other physiological parameters were measured prior to sedation and colonoscopy (baseline) and at seven other timepoints through departure from recovery. Depth of anesthesia was measured using a Narcotrend monitor.

RESULTS

Significantly fewer patients in the treatment group experienced a ⩾4% decrease from baseline SpO₂ (2/16) than patients in the control group (10/16; p = 0.004). The two groups were comparable with regard to respiratory rate, systolic and diastolic blood pressures, mean arterial pressure, and heart rate.

CONCLUSION

TEAS applied at PC6 with 2 Hz frequency was feasible and may be helpful in reducing the rate of hypoxia in elderly patients during colonoscopy.Trial registration number: NCT03775122 (ClinicalTrials.gov).

Capnography monitoring in procedural intravenous sedation: a systematic review and meta-analysis

OBJECTIVES

Currently, procedural sedation in the clinical setting relies heavily on the use of pulse oximetry to monitor hypoxemia. Different studies suggest that incidence of hypoxemia and incidence of arterial oxygen desaturation are reduced by early intervention via capnography monitoring. The aim of this article was to discuss the importance of implementing capnography monitoring during procedural sedations performed in a dental setting and determine whether additional capnographic monitoring reduces the incidence of arterial oxygen desaturation and the overall complications rate.

MATERIALS AND METHODS

Two independent reviewers conducted electronic (PubMed and EMBASE) and manual searches up to February 2020. Randomized clinical trials (RCTs), including both patients under procedural sedation monitored by capnography and oximetry, and reporting the incidence of hypoxemia or episodes of oxygen desaturation were included. Risk ratio was used to compare the outcomes (i.e., the incidence of hypoxemia, the episodes of oxygen desaturation, the detection of apnea, the reduction of events of bradycardia, and hypotension) between patients monitored by capnography and standard approach.

RESULTS

Fourteen randomized clinical trials fulfilling the inclusion criteria were selected. The analysis revealed that capnography monitoring group showed the lower incidence of hypoxemia (RR 0.76, 95%CI 0.70 to 0.83, p < 0.001) and the episodes of oxygen desaturation (RR 0.79, 95%CI 0.71 to 0.87, p < 0.001) compared with the oximetry monitoring group. Apnea was detected in capnography monitoring earlier than standard monitoring (RR 2.60, 95%CI 2.30 to 2.93, p < 0.001). No significant difference was found between capnography and standard monitoring groups in terms of reduction of events of bradycardia (RR 1.17, 95%CI 0.91 to 1.50, p = 0.225) and hypotension (RR 0.96, 95%CI 0.76 to 1.21, p = 0.746).

CONCLUSION

Capnography monitoring reduced incidence of hypoxemia during procedural sedations. Within the limitations of this review, we suggest that the application of capnography during procedural sedation would decrease the frequency of oxygen desaturation events and incidence of hypoxemia.

CLINICAL RELEVANCE

Training and instructing dental providers on using capnography monitoring would help in reducing adverse events during intravenous sedation.

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).

Monitoring standards in sedation and analgesia: the odyssey of capnography in sedation for gastroenterology procedures

PURPOSE OF REVIEW

Capnography is an excellent tool for early detection of hypoxemia and apnea in patients undergoing sedation for gastrointestinal endoscopy. The current American Society of Anesthesiology (ASA) guidelines recommend the use of capnography in any patient undergoing moderate sedation. The purpose of this review was to compile the most recent data available on capnography use in gastrointestinal endoscopy with the focus primarily on the use of capnography in moderate sedation cases.

RECENT FINDINGS

Recent high-quality studies have evaluated the utility of capnography in low risk patients undergoing moderate sedation and have found no benefit with addition of capnography.

SUMMARY

Capnography is beneficial when used for patients who are at a higher risk for sedation-related complications. There is no benefit when capnography is used in low risk patients undergoing routine upper endoscopy and colonoscopy under moderate sedation but there is benefit when used in advanced endoscopic procedures that require deeper sedation and have longer procedure times.

Benefits and harms of capnography during procedures involving moderate sedation: A rapid review and meta-analysis

BACKGROUND

Patient safety is a priority in dentistry. Evaluating the benefits and harms associated with the addition of capnography to standard monitoring during moderate sedation for adult patients in the dental practice setting is needed.

TYPES OF STUDIES REVIEWED

The authors used rapid review methodology to identify relevant systematic reviews, which they updated through a systematic search by using the same search strategy as the identified reviews. The authors searched PubMed and Google Scholar and through the references of the identified systematic reviews, which yielded 2,892 studies. Inclusion criteria were that the article was available in English, was original research in adult humans who had undergone moderate procedural sedation, and involved comparing standard monitoring with the addition of capnography.

RESULTS

Sixteen studies were eligible, involving 3,866 adults undergoing procedural sedation. The authors used the Grading of Recommendations Assessment, Development and Evaluation approach to evaluate the evidence and rate it as being of moderate to low quality because of high risk of bias and heterogeneous effects for the outcomes of hypoxemia and adverse respiratory events. Capnography had higher sensitivity to detect adverse respiratory events than did standard monitoring alone (0.92; 95% confidence interval, 0.65 to 0.99) and may reduce the risk of developing hypoxemia by 31% (risk ratio, 0.69; 95% confidence interval, 0.57 to 0.82). Capnography did not affect the risk of developing serious adverse events, procedure time, sedation quality, or patient satisfaction.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Adding capnography to standard monitoring of adults during moderate sedation may reduce the risk of developing hypoxemia, increase detection of adverse respiratory events, and is not associated with additional harms. These findings suggest routine use of capnography during moderate sedation has the potential to reduce adverse anesthetic outcomes in dental practice.

Sequence analysis of capnography waveform abnormalities during nurse-administered procedural sedation and analgesia in the cardiac catheterization laboratory

Identifying common patterns in capnography waveform abnormalities and the factors that influence these patterns could yield insights to optimize responses to sedation-induced respiratory depression. Respiratory state sequences for 102 patients who had a procedure in a cardiac catheterisation laboratory with procedural sedation and analgesia were developed by classifying each second of procedures into a state of normal breathing or other capnography waveform abnormalities based on pre-specified cut-offs for respiratory rate and end-tidal CO2 concentration. Hierarchical clustering identified four common patterns in respiratory state sequences, which were characterized by a predominance of the state assigned normal breathing (n = 42; 41%), hypopneic hypoventilation (n = 38; 38%), apnea (n = 15; 15%) and bradypneic hypoventilation (n = 7; 7%). A multivariable distance matrix regression model including demographic and clinical variables explained 28% of the variation in inter-individual differences in respiratory state sequences. Obstructive sleep apnea (R2 = 2.4%; p = 0.02), smoking status (R2 = 2.8%; p = 0.01), Charlson comorbidity index score (R2 = 2.5%; p = 0.021), peak transcutaneous carbon dioxide concentration (R2 = 4.1%; p = 0.002) and receiving an intervention to support respiration (R2 = 5.6%; p = 0.001) were significant covariates but each explained only small amounts of the variation in respiratory state sequences. Oxygen desaturation (SpO2 < 90%) was rare (n = 3; 3%) and not associated with respiratory state sequence trajectories.

Recommendations for good practice for sedation in assisted conception

Conscious sedation is a commonly used approach to provide pain relief during transvaginal oocyte retrieval. It has been shown to be effective with high levels of acceptability and patient satisfaction. Fundamental Standards and Development Standards in safe sedation practice have been set out by the Royal College of Anaesthetists and they recommend that Royal Colleges, in association with the relevant sub-specialty organizations, should develop guidelines on sedation methods appropriate to clinical practice in their sphere of influence. This Policy and Practice paper outlines the human resources and equipment necessary to optimize patients' safety for the administration of intravenous (I.V.) sedation in assisted conception units, based on the most current evidence and guidance available.

Novel mainstream capnometer system is safe and feasible even under CO2 insufflation during ERCP-related procedure: a pilot study

Background and aims

There is a need to safely achieve conscious sedation during endoscopic retrograde cholangiopancreatography (ERCP). We evaluated the safety and feasibility of a mainstream capnometer system to monitor apnoea during ERCP under CO₂ insufflation.

Methods

Non-intubated adult patients undergoing ERCP-related procedures with intravenous sedation were enrolled. End-tidal CO₂ (EtCO₂) was continuously monitored during the procedure under CO₂ insufflation using a mainstream capnometer system, comprising a capnometer and a specially designed bite block for upper gastrointestinal endoscopy and ERCP. Oxygen saturation (SpO₂) was also monitored continuously during the procedure. In this study, we evaluated the safety and feasibility of the capnometer system.

Results

Eleven patients were enrolled. Measurement of EtCO₂ concentration was possible from the beginning to the end of the procedure in all 11 cases. There was no measurement failure, dislocation of the bite block, or adverse event related to the bite block. Apnoea linked to hypoxaemia occurred five times (mean duration, 174.4 s).

Conclusion

This study confirmed that apnoea was detected earlier than when using a percutaneous oxygen monitor. Measurement of EtCO₂ concentration using the newly developed mainstream capnometer system was feasible and safe even under CO₂ insufflation.

Nasal positive pressure with the SuperNO2VA™ device decreases sedation-related hypoxemia during pre-bariatric surgery EGD

INTRODUCTION

Pre-operative esophagogastroduodenoscopy (EGD) is becoming routine practice in patients undergoing bariatric surgery. Many patients with morbid obesity have obstructive sleep apnea (OSA), which can worsen hypoxia during an EGD. In this study, we report our outcomes using the SuperNO₂VA™ device, a sealed nasal positive airway pressure mask designed to deliver high-fraction inhaled oxygen and titratable positive pressure compared to conventional nasal cannula.

METHODS

Between June 2016 and August 2017, we conducted a prospective observational study that included 56 consecutive patients who presented for EGD prior to bariatric surgery. Airway management was done using either the SuperNO₂VA™ (N = 26) device or conventional nasal cannula (N = 30). Patient demographics, procedure details, and outcomes were compared between the two groups.

RESULTS

The SuperNO₂VA™ group had a lower median age compared to the control group (38.5 vs. 48.5 years, p = 0.04). These patients had a higher body mass index (BMI) (47.4 vs. 40.5, IQR, p < 0.0001), higher ASA class (p = 0.03), and were more likely to have OSA (53.9% vs. 26.7%, p = 0.04). Desaturation events were significantly lower in the SuperNO₂VA™ group (11.5% vs. 46.7%, p = 0.004) and the median lowest oxygen saturation was higher in the SuperNO₂VA™ group (100% vs. 90.5%, p < 0.0001).

DISCUSSION

This is the first study to report on the use of the SuperNO₂VA™ device in bariatric patients undergoing pre-operative screening EGD. The use of the SuperNO₂VA™ device offers a clinical advantage compared to the current standard of care. Our data demonstrate that patients with higher BMI, higher ASA classification, and OSA were more likely to have the SuperNO₂VA™ device used; yet, paradoxically, these patients were less likely to have issues with desaturation events. Use of this device can optimize care in this challenging patient population by minimizing the risks of hypoventilation.

Capnography Monitoring for Patients Undergoing Moderate Sedation: An SGNA Fellowship Project

The purpose of this Society of Gastroenterology Nurses and Associates Fellowship project was to determine whether capnography is more accurate than oximetry in identifying symptoms of respiratory depression in patients undergoing moderate sedation. Capnography provides an early warning of respiratory depression and airway compromise, especially when the medications used for sedation include opiates and benzodiazepines. It is a standard of care according to the American Society of Anesthesiologists that should be adopted in order to provide the safest possible environment for the delivery of moderate sedation. During this project, the nursing staff were educated on the importance and usage of capnography. Evidence was gathered that helped show that by using capnography, nurses were able to identify signs of respiratory depression earlier and more frequently than with the use of oximetry and cardiac monitoring alone.

The addition of capnography to standard monitoring reduces hypoxemic events during gastrointestinal endoscopic sedation: a systematic review and meta-analysis

Background

The use of capnography monitoring devices has been shown to lower the rates of hypoxemia via early detection of respiratory depression, and facilitate more accurate titration of sedatives during procedures. The aim of the current meta-analysis was to compare the incidence of hypoxemia associated with standard monitoring alone during gastrointestinal endoscopy to that associated with standard monitoring with the addition of capnography.

Methods

The MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials scientific databases were searched to identify relevant studies. We performed a meta-analysis of randomized controlled trials undertaken up to January 2018 that met our predefined inclusion criteria. The study outcome measures were incidence of hypoxemia, severe hypoxemia, apnea, the use of assisted ventilation, the use of supplemental oxygen, and change in vital signs.

Results

We included nine trials assessing a total of 3,088 patients who underwent gastrointestinal procedural sedation. Meta-analysis of study outcome revealed that capnography significantly reduced the incidence of hypoxemia (odds ratio 0.61, 95% CI 0.49–0.77) and severe hypoxemia (odds ratio 0.53, 95% CI 0.35–0.81). However, there were no significant differences in other outcomes including incidence of apnea, assisted ventilation, supplemental oxygen, and changes in vital signs. Early procedure termination and patient satisfaction-related outcomes did not differ significantly in the capnography group and the standard monitoring group.

Conclusion

This study indicates that capnography monitoring is an important addition with regard to the detection of hypoxemia during gastrointestinal procedural sedation, and should be considered in routine monitoring during gastrointestinal endoscopy.

Practice Guidelines for Moderate Procedural Sedation and Analgesia 2018

Supplemental Digital Content is available in the text.

Clinical and economic burden of procedural sedation-related adverse events and their outcomes: analysis from five countries

Background

Studies have reported on the incidence of sedation-related adverse events (AEs), but little is known about their impact on health care costs and resource use.

Methods

Health care providers and payers in five countries were recruited for an online survey by independent administrators to ensure that investigators and respondents were blinded to each other. Surveys were conducted in the local language and began with a “screener” to ensure that respondents had relevant expertise and experience. Responses were analyzed using Excel and R, with the Dixon’s Q statistic used to identify and remove outliers. Global and country-specific average treatment patterns were calculated via bootstrapping; costs were mean values. The sum product of costs and intervention probability gave a cost per AE.

Results

Responses were received from 101 providers and 26 payers, the majority having >5 years of experience. At a minimum, the respondents performed a total of 3,430 procedural sedations per month. All AEs detailed occurred in clinical practice in the last year and were reported to cause procedural delays and cancellations in some patients. Standard procedural sedation costs ranged from €74 (Germany) to $2,300 (US). Respondents estimated that AEs would increase costs by between 16% (Italy) and 179% (US). Hypotension was reported as the most commonly observed AE with an associated global mean cost (interquartile range) of $43 ($27–$68). Other frequent AEs, including mild hypotension, bradycardia, tachycardia, mild oxygen desaturation, hypertension, and brief apnea, were estimated to increase health care spending on procedural sedation by $2.2 billion annually in the US.

Conclusion

All sedation-related AEs can increase health care costs and result in substantial delays or cancellations of subsequent procedures. The prevention of even minor AEs during procedural sedation may be crucial to ensuring its value as a health care service.

Standards of care for procedural sedation: Focus on differing perceptions among societies

Adherence to established standards of care is important for anaesthesiologists to avoid undesirable legal consequences of their actions. The judiciary lays stress on the need to perpetuate healthy doctor–patient correspondence, good documentation, and to bestow a justifiable standard of care. But what defines standard of care and who delineates such standards is something that lacks clarity. The American Society for Gastrointestinal Endoscopy (ASGE) has recently released updated guidelines on the use of sedation and anaesthesia for gastrointestinal endoscopic procedures. Almost simultaneously, the American Society of Anesthesiologists (ASA) has brought out practice guidelines for moderate sedation and analgesia. In contrast to the ASA recommendations, ASGE does not view capnography as an essential monitoring modality for endoscopic procedures with moderate sedation because it has apparently not been shown to improve patient safety. However, they do agree that evidence supports its deployment during deep sedation. These differences in views between guidelines published by societies of substantial academic and clinical standing can confuse the agreement over what constitutes standard of care for the particular speciality. It is the expectation that guidelines and consensus statements in anaesthesiology be preferably issued by national or international organizations of the same speciality.

Microstream capnography during conscious sedation with midazolam for oral surgery: a randomised controlled trial

Objectives/Aims:

There has been no dentistry-specific published data supporting the use of monitoring with capnography for dental sedation. Our aim was to determine if adding capnography to standard monitoring during conscious sedation with midazolam would decrease the incidence of hypoxaemia.

Materials and Methods:

A randomised controlled trial was conducted in which all patients (ASA I and II) received standard monitoring and capnography, but were randomised to whether staff could view the capnography (intervention) or were blinded to it (control). The primary outcome was the incidence of hypoxaemia (SpO₂⩽94%).

Results:

We enrolled 190 patients, mean age 31 years (range, 14–62 years). There were 93 patients in the capnography group and 97 in the control group. The mean cumulative dose of midazolam titrated was 6.94 mg (s.d., 2.31; range, 3–20 mg). Six (3%) patients, three in each group, required temporary supplemental oxygen. There was no statistically significant difference between the capnography and control groups for the incidence of hypoxaemia: 34.4 vs 39.2% (P=0.4962, OR=0.81, 95% CI: 0.45–1.47).

Conclusions:

We were unable to confirm an additive role for capnography to prevent hypoxaemia during conscious sedation with midazolam for patients not routinely administered supplemental oxygen.

Patient safety during procedural sedation using capnography monitoring: a systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of capnography monitoring on sedation-related adverse events during procedural sedation and analgesia (PSA) administered for ambulatory surgery relative to visual assessment and pulse oximetry alone.

DESIGN AND SETTING

Systematic literature review and random effects meta-analysis of randomised controlled trials (RCTs) reporting sedation-related adverse event incidence when adding capnography to visual assessment and pulse oximetry in patients undergoing PSA during ambulatory surgery in the hospital setting. Searches for eligible studies published between 1 January 1995 and 31 December 2016 (inclusive) were conducted in PubMed, the Cochrane Library and EMBASE without any language constraints. Searches were conducted in January 2017, screening and data extraction were conducted by two independent reviewers, and study quality was assessed using a modified Jadad scale.

INTERVENTIONS

Capnography monitoring relative to visual assessment and pulse oximetry alone.

PRIMARY AND SECONDARY OUTCOME MEASURES

Predefined endpoints of interest were desaturation/hypoxaemia (the primary endpoint), apnoea, aspiration, bradycardia, hypotension, premature procedure termination, respiratory failure, use of assisted/bag-mask ventilation and death during PSA.

RESULTS

The literature search identified 1006 unique articles, of which 13 were ultimately included in the meta-analysis. Addition of capnography to visual assessment and pulse oximetry was associated with a significant reduction in mild (risk ratio (RR) 0.77, 95% CI 0.67 to 0.89) and severe (RR 0.59, 95% CI 0.43 to 0.81) desaturation, as well as in the use of assisted ventilation (OR 0.47, 95% CI 0.23 to 0.95). No significant differences in other endpoints were identified.

CONCLUSIONS

Meta-analysis of 13 RCTs published between 2006 and 2016 showed a reduction in respiratory compromise (from respiratory insufficiency to failure) during PSA with the inclusion of capnography monitoring. In particular, use of capnography was associated with less mild and severe oxygen desaturation, which may have helped to avoid the need for assisted ventilation.

The relationship between minute ventilation and end tidal CO2 in intubated and spontaneously breathing patients undergoing procedural sedation

BACKGROUND

Monitoring respiratory status using end tidal CO2 (EtCO2), which reliably reflects arterial PaCO2 in intubated patients under general anesthesia, has often proven both inaccurate and inadequate when monitoring non-intubated and spontaneously breathing patients. This is particularly important in patients undergoing procedural sedation (e.g., endoscopy, colonoscopy). This can be undertaken in the operating theater, but is also often delivered outside the operating room by non-anesthesia providers. In this study we evaluated the ability for conventional EtCO2 monitoring to reflect changes in ventilation in non-intubated surgical patients undergoing monitored anesthesia care and compared and contrasted these findings to both intubated patients under general anesthesia and spontaneously breathing volunteers.

METHODS

Minute Ventilation (MV), tidal volume (TV), and respiratory rate (RR) were continuously collected from an impedance-based Respiratory Volume Monitor (RVM) simultaneously with capnography data in 160 patients from three patient groups: non-intubated surgical patients managed using spinal anesthesia and Procedural Sedation (n = 58); intubated surgical patients under General Anesthesia (n = 54); and spontaneously breathing Awake Volunteers (n = 48). EtCO2 instrument sensitivity was calculated for each patient as the slope of a Deming regression between corresponding measurements of EtCO2 and MV and expressed as angle from the x-axis (θ). All data are presented as mean ± SD unless otherwise indicated.

RESULTS

While, as expected, EtCO2 and MV measurements were negatively correlated in most patients, we found gross systematic differences across the three cohorts. In the General Anesthesia patients, small changes in MV resulted in large changes in EtCO2 (high sensitivity, θ = -83.6 ± 9.9°). In contrast, in the Awake Volunteers patients, large changes in MV resulted in insignificant changes in EtCO2 (low sensitivity, θ = -24.7 ± 19.7°, p < 0.0001 vs General Anesthesia). In the Procedural Sedation patients, EtCO2 sensitivity showed a bimodal distribution, with an approximately even split between patients showing high EtCO2 instrument sensitivity, similar to those under General Anesthesia, and patients with low EtCO2 instrument sensitivity, similar to the Awake Volunteers.

CONCLUSIONS

When monitoring non-intubated patients undergoing procedural sedation, EtCO2 often provides inadequate instrument sensitivity when detecting changes in ventilation. This suggests that augmenting standard patient care with EtCO2 monitoring is a less than optimal solution for detecting changes in respiratory status in non-intubated patients. Instead, adding direct monitoring of MV with an RVM may be preferable for continuous assessment of adequacy of ventilation in non-intubated patients.

On the Horizon: The Future of Procedural Sedation

Sedation plays an integral part in endoscopy. By achieving patient comfort, it allows for a better examination and enhances patient satisfaction. Various medications have been used, propofol being the current favorite. With emphasis on patient safety and quality of endoscopy, various new medications in different combinations are being used to achieve adequate sedation and not escalate the cost of the procedure. With the advent of newer medications and newer modalities to administer these medications, there is need for more specialized training for the endoscopist to feel comfortable while using these medications.