Effects of sedation and supplemental oxygen during upper alimentary tract endoscopy

Effect of remimazolam tosilate on the incidence of hypoxemia in elderly patients undergoing gastrointestinal endoscopy: A bi-center, prospective, randomized controlled study

Background: Remimazolam tosilate is a new ultra-short-acting benzodiazepine sedative medicine. In this study, we evaluated the effect of remimazolam tosilate on the incidence of hypoxemia during sedation in elderly patients undergoing gastrointestinal endoscopy. Methods: Patients in the remimazolam group received an initial dose of 0.1 mg/kg and a bolus dose of 2.5 mg of remimazolam tosilate, whereas patients in the propofol group received an initial dose of 1.5 mg/kg and a bolus dose of 0.5 mg/kg of propofol. Patients received ASA standard monitoring (heart-rate, non-invasive blood pressure, and pulse oxygen saturation) during the entire examination process. The primary outcome was the incidence of moderate hypoxemia (defined as 85%≤ SpO₂< 90%, >15s) during the gastrointestinal endoscopy. The secondary outcomes included the incidence of mild hypoxemia (defined as SpO₂ 90%-94%) and severe hypoxemia (defined as SpO₂< 85%, >15s), the lowest pulse oxygen saturation, airway maneuvers used to correct hypoxemia, patient's hemodynamic as well as other adverse events. Results: 107 elderly patients (67.6 ± 5.7 years old) in the remimazolam group and 109 elderly patients (67.5 ± 4.9 years old) in the propofol group were analyzed. The incidence of moderate hypoxemia was 2.8% in the remimazolam group and 17.4% in the propofol group (relative risk [RR] = 0.161; 95% confidence interval [CI], 0.049 to 0.528; p < 0.001). The frequency of mild hypoxemia was less in the remimazolam group, but not statistically significant (9.3% vs. 14.7%; RR = 0.637; 95% CI, 0.303 to 1.339; p = 0.228). There was no significant difference in the incidence of severe hypoxemia between the two groups (4.7% vs. 5.5%; RR = 0.849; 95% CI, 0.267 to 2.698; p = 0.781). The median lowest SpO₂ during the examination was 98% (IQR, 96.0%-99.0%) in patients in the remimazolam group, which was significantly higher than in patients in the propofol group (96%, IQR, 92.0%-99.0%, p < 0.001). Patients in the remimazolam group received more drug supplementation during endoscopy than patients in the propofol group (p = 0.014). There was a statistically significant difference in the incidence of hypotension between the two groups (2.8% vs. 12.8%; RR = 0.218; 95% CI, 0.065 to 0.738; p = 0.006). No significant differences were found in the incidence of adverse events such as nausea and vomiting, dizziness, and prolonged sedation. Conclusion: This study explored the safety of remimazolam compared with propofol during gastrointestinal endoscopy in elderly patients. Despite the increased supplemental doses during sedation, remimazolam improved risk of moderate hypoxemia (i.e., 85%≤ SpO₂ < 90%) and hypotension in elderly patients.

Practical considerations for colorectal cancer screening in older adults

Recent guidelines recommend that colorectal cancer (CRC) screening after age 75 be considered on an individualized basis, and discourage screening for people over 85 due to competing causes of mortality. Given the heterogeneity in the health of older individuals, and lack of data within current guidelines for personalized CRC screening approaches, there remains a need for a clearer framework to inform clinical decision-making. A revision of the current approach to CRC screening in older adults is even more compelling given the improvements in CRC treatment, post-treatment survival, and increasing life expectancy in the population. In this review, we aim to examine the personalization of CRC screening cessation based on specific factors influencing life and health expectancy such as comorbidity, frailty, and cognitive status. We will also review screening modalities and endoscopic technique for minimizing risk, the risks of screening unique to older adults, and CRC treatment outcomes in older patients, in order to provide important information to aid CRC screening decisions for this age group. This review article offers a unique approach to this topic from both the gastroenterologist and geriatrician perspective by reviewing the use of specific clinical assessment tools, and addressing technical aspects of screening colonoscopy and periprocedural management to mitigate screening-related complications.

Cardiorespiratory complications of digestive endoscopy not related to sedation

Although digestive endoscopy is considered to be a safe procedure, both the growing complexity of the techniques and the underlying diseases of patients increase the risk of adverse events during the procedure. Cardiorespiratory events are the most frequent complications, and can occur in patients with or without sedation, although they appear more often when the patient is sedated. The body's physiological response to stress is what causes these adverse events, which are generally mild and transient, although they can be serious. They are more frequent in patients with cardiopulmonary diseases, which logically increase risk. The autonomic nervous system, through its sympathetic and parasympathetic branches, is primarily responsible for these alterations. Patients with asthma or chronic obstructive pulmonary disease have a higher risk of hypoxemia, bronchospasm, and arrhythmia during the endoscopic procedure. Patients with arrhythmia and ischemic heart disease have a higher risk of myocardial ischemia and heart rhythm disturbances. The risk of adverse events during the procedure can be reduced by reviewing the patient's medical history along with a basic clinical examination before endoscopy. A brief interrogation about symptom control can also help the safety of endoscopy.

Difficult Airway Society guidelines for awake tracheal intubation (ATI) in adults

Awake tracheal intubation has a high success rate and a favourable safety profile but is underused in cases of anticipated difficult airway management. These guidelines are a comprehensive document to support decision making, preparation and practical performance of awake tracheal intubation. We performed a systematic review of the literature seeking all of the available evidence for each element of awake tracheal intubation in order to make recommendations. In the absence of high‐quality evidence, expert consensus and a Delphi study were used to formulate recommendations. We highlight key areas of awake tracheal intubation in which specific recommendations were made, which included: indications; procedural setup; checklists; oxygenation; airway topicalisation; sedation; verification of tracheal tube position; complications; management of unsuccessful awake tracheal intubation; post‐tracheal intubation management; consent; and training. We recognise that there are a range of techniques and regimens that may be effective and one such example technique is included. Breaking down the key practical elements of awake tracheal intubation into sedation, topicalisation, oxygenation and performance might help practitioners to plan, perform and address complications. These guidelines aim to support clinical practice and help lower the threshold for performing awake tracheal intubation when indicated.

Novel mandibular advancement bite block with supplemental oxygen to both nasal and oral cavity improves oxygenation during esophagogastroduodenoscopy: a bench comparison

Drug-induced respiratory depression is a major cause of serious adverse events. Adequate oxygenation is very important during sedated esophagogastroduodenoscopy (EGD). Nasal breathing often shifts to oral breathing during open mouth EGD. A mandibular advancement bite block was developed for EGD using computer-assisted design and three-dimensional printing techniques. The mandible is advanced when using this bite block to facilitate airway opening. The device is composed of an oxygen inlet with one opening directed towards the nostril and another opening directed towards the oral cavity. The aim of this bench study was to compare the inspired oxygen concentration (FiO₂) provided by the different nasal cannulas, masks, and bite blocks commonly used in sedated EGD. A manikin head was connected to one side of a two-compartment lung model by a 7.0 mm endotracheal tube with its opening in the nasopharyngeal position. The other compartment was driven by a ventilator to mimic "patient" inspiratory effort. Using this spontaneously breathing lung model, we evaluated five nasal cannulas, two face masks, and four new oral bite blocks at different oxygen flow rates and different mouth opening sizes. The respiratory rate was set at 12/min with a tidal volume of 500 mL and 8/min with a tidal volume of 300 mL. Several Pneuflo resistors of different sizes were used in the mouth of the manikin head to generate different degrees of mouth opening. FiO₂ was evaluated continuously via the endotracheal tube. All parameters were evaluated using a Datex anesthesia monitoring system. The mandibular advancement bite block provided the highest FiO₂ under the same supplemental oxygen flow. The FiO₂ was higher for devices with oxygen flow provided via an oral bite block than that provided via the nasal route. Under the same supplemental oxygen flow, the tidal volume and respiratory rate also played an important role in the FiO₂. A low respiratory rate with a smaller tidal volume has a relative high FiO₂. The ratio of nasal to oral breathing played an important role in the FiO₂ under hypoventilation but less role under normal ventilation. Bite blocks deliver a higher FiO₂ during EGD. The ratio of nasal to oral breathing, supplemental oxygen flow, tidal volume, and respiratory rate influenced the FiO₂ in most of the supplemental oxygen devices tested, which are often used for conscious sedation in patients undergoing EGD and colonoscopy.

Practice Guidelines for Moderate Procedural Sedation and Analgesia 2018

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Gastrointestinal endoscopy in the elderly: current issues

Even though endoscopy is performed in patients of all ages, currently there is little literature on this topic in elderly patients. As a result of population demographics the use of endoscopy is expected to rise in this section of the population. Elderly patients represent a special group of patients, as they usually have a higher incidence of co-morbid diseases and may be more susceptible to endoscopic interventions. Due to the decreased physiologic reserve and associated diseases, complications in elderly patients can be more severe than in adult or young subjects. Moreover, ethical considerations play a special role in elderly frail patients with a potential poor prognosis. Thus, the endoscopist needs to pay special attention when considering or performing endoscopy in elderly patients. The aim of this article is to review the role of endoscopy in elderly patients, paying special emphasis on indications, special precautions and specific interventions.

Sedation during endoscopy for patients at risk of obstructive sleep apnea

BACKGROUND

Obstructive sleep apnea (OSA) has become increasingly prevalent in the United States and often goes undiagnosed.

OBJECTIVE

To assess the proportion of patients undergoing routine endoscopic procedures who are at risk of OSA and to determine whether these patients are at risk of sedation-related hypoxia.

DESIGN AND SETTING

Prospective case-control study at an academic medical center.

PATIENTS AND INTERVENTIONS

Patients undergoing routine EGD and colonoscopy were administered the Berlin Questionnaire, a brief validated survey that stratifies patients into high or low risk of OSA. Data on pulse oximetry and oxygen use were collected.

MAIN OUTCOME MEASUREMENTS

Rates of transient hypoxia, defined as a pulse oximetry measurement less than 92% requiring an increase in supplemental oxygen were compared between the high- and low-risk OSA groups.

RESULTS

Of the 261 prospectively recruited patients, 28 were excluded for violating study protocol. Ninety (39%) of the remaining 233 patients were scored as being at high risk of OSA. There was no significant difference in the rate of transient hypoxia between the high- and low-risk groups (odds ratio 1.48; 95% CI, 0.58-3.80).

LIMITATIONS

Single-center study. OSA was not confirmed with a sleep study.

CONCLUSION

Approximately one third of patients undergoing routine outpatient endoscopic procedures at a university hospital scored as being at high risk of OSA. There was no significant difference in the rates of transient hypoxia between high- and low-risk groups, suggesting that the majority of patients with no diagnosis of OSA can undergo conscious sedation for routine endoscopic procedures with standard monitoring practices.

Gastrointestinal bleeding in the elderly

Among patients with acute gastrointestinal bleeding, older age is associated with an increased rate of comorbidity, greater medication use, and atypical clinical presentations. The aging of the population makes the evaluation and management of gastrointestinal bleeding in the elderly a special and increasingly common clinical challenge. The unique features and common causes of upper and lower gastrointestinal bleeding in the elderly are reviewed. Important management issues considered include hemodynamic resuscitation; anticoagulation; and medical, surgical, and endoscopic therapy.

Conscious sedation and cardiorespiratory safety during colonoscopy

BACKGROUND

Cardiorespiratory events during colonoscopy are common. The effect of sedative premedication on cardiorespiratory parameters during colonoscopy has not been studied in controlled, prospective trials.

METHODS

One hundred eighty patients undergoing colonoscopy were divided into 3 groups: (1) sedation with intravenous midazolam (midazolam group); (2) sedation with intravenous saline (placebo group); and (3) no intravenous cannula (control group). Arterial oxygen saturation (SaO(2)), systolic and diastolic blood pressure and continuous electrocardiogram were recorded prior to, during and after the endoscopic procedure.

RESULTS

Midazolam produced lower SaO(2) values during colonoscopy compared with placebo or control groups (p < 0.001, repeated measures analysis of variance). Systolic and diastolic blood pressure during colonoscopy were lower in the midazolam group than in the placebo group (p < 0.01 and p < 0.05, respectively), but no difference was found between the midazolam and the control groups. Hypotension (systolic blood pressure less than 100 mm Hg) occurred more frequently in the midazolam group (19%) than in the placebo (3%; p < 0.01) or control groups (7%; p < 0.05). ST-segment depression developed in 7% of patients during the recording with no difference between the groups. In 75% of cases ST-depression appeared prior to the endoscopic procedure.

CONCLUSIONS

Premedication with midazolam induced a statistically significant decrease in arterial oxygen saturation and increased the risk for hypotension. However, colonoscopy proved to be a safe procedure both with and without sedation.

Hypoxia during upper gastrointestinal endoscopy with and without sedation and the effect of pre-oxygenation on oxygen saturation

In Study A, the incidence of arterial oxygen desaturation was studied using pulse oximetry (SaO2) in 100 sedated and 100 nonsedated patients breathing room air who underwent diagnostic upper gastrointestinal endoscopy. Hypoxia (SaO2 92% or less of at least 15 s duration) occurred in 17% and 6% of sedated patients and nonsedated patients, respectively (p < 0.03). Mild desaturation (SaO2 94% or less and less than 15 s duration) occurred in 47% of sedated patients compared with 12% of nonsedated patients (p < 0.001). In Study B, the effects of supplementary oxygen therapy and the effects of different pre-oxygenation times on arterial oxygen saturation (SaO2) in sedated patients were studied using pulse oximetry. One hundred and twenty patients who underwent diagnostic upper gastrointestinal endoscopy with intravenous sedation were studied. Patients were randomly allocated to one of four groups: Group A (n = 30) received no supplementary oxygen while Groups B-D received supplementary oxygen at 4 1 x min(-1) via nasal cannulae. The pre-oxygenation time in Group B (n = 30) was zero minutes, Group C (n = 30) was 2 min and Group D (n = 30) was 5 min before sedation and introduction of the endoscope. Hypoxia occurred in seven of the 30 patients in Group A and none in groups B, C and D (p < 0.001). We conclude that desaturation and hypoxia is common in patients undergoing upper gastrointestinal endoscopy with and without sedation. Sedation significantly increases the incidence of desaturation and hypoxia. Supplementary nasal oxygen at 4 1 x min(-1) in sedated patients abolishes desaturation and hypoxia. Pre-oxygenation confers no additional benefit.

No effect of oxygen therapy on myocardial ischaemia during gastroscopy

BACKGROUND

Myocardial ischaemia (defined as an ST-segment depression on ECG) may occur during upper gastrointestinal endoscopy, but the mechanism is still unknown. The aim of our study was to evaluate the effect of oxygen therapy and tachycardia on the occurrence of ST-segment depression during routine diagnostic esophagogastroduodenoscopy.

METHODS

Eighty-nine consecutive patients were randomized to receive either oxygen (21/min by nasal prongs) or nothing during endoscopy, in which arterial oxygen saturation was measured by continuous pulse oximetry, and ECG was measured continuously with a Holter tape recorder.

RESULTS

A total of 28 patients (12 receiving oxygen) developed ST-segment depression ( > 0.1 mV) during endoscopy. In 22 patients (12 receiving oxygen) ST depression was related to tachycardia, and in 5 of these (none receiving oxygen) simultaneous episodic hypoxaemia was present during the event. Thus, in every case of ST depression related to episodic hypoxaemia there was simultaneous tachycardia. In six patients developing ST depression during endoscopy we did not find preendoscopy levels, and 63 patients (29 receiving oxygen) developed tachycardia during the procedure (rate > 100 min-1_.

CONCLUSIONS

Oxygen therapy had no significant effect on the occurrence of ST-segment depression during upper gastrointestinal endoscopy. The results suggest that tachycardia is more important than hypoxaemia in the pathogenesis of ST depression during gastroscopy.

[Use of Diprivan for digestive system endoscopy]

After evaluation of the patient's clinical condition and appropriate premedication is seems reasonable to suggest for: 1. Endoscopic procedures involving the gastro-intestinal tract: slow, titrated induction, using 0.5 to 1 mg.kg-1 of propofol, until the required level of sedation has been achieved; this may or not be preceded by the injection of a low dose of midazolam (0.02 to 0.03 mg.kg-1) or of alfentanil (5 micrograms.kg-1); maintenance is achieved by bolus injections of 20 mg (up to 0.5 mg.kg-1); maintenance of spontaneous ventilation, with oxygen administration is the rule; SpO2 is monitored routinely; anaesthesia has to be performed according to the recommendations of the French Society of Anaesthesia and Intensive Care (SFAR) and the anaesthetist must be prepared to manage any incident during the endoscopy and the recovery period. 2. Procedures involving the biliary tract and the oesophagus, which require deeper anaesthesia: induction should again be titrated using a very slow infusion, with doses ranging from 0.9 to 2.2 mg.kg-1); the maintenance requires a continuous infusion, doses ranging from 4 to 6 mg.kg-1.h-1 when propofol is administered alone and from 4 to 12 mg.kg-1.h-1 when combined with an opioid; continuous oxygenation is necessary using a nasal airway; the need for intubation depends on the type of procedure and the status of the patient; the same monitoring devices and similar safety measures are required during and after procedure as for any anaesthetic or sedation, especially when it is performed in day-case patients or outside the operating theatre.