Hypoxemia during procedural sedation in adult patients: a retrospective observational study

The periprocedural respiratory safety of propofol sedation in patients with a motor neuron disease undergoing percutaneous endoscopic gastrostomy insertion

Motor neuron diseases (MND), such as Amyotrophic Lateral Sclerosis (ALS) and Primary Lateral Sclerosis (PLS), may cause swallowing and respiratory problems, due to muscle weakness. Chronic enteral feeding via percutaneous endoscopic gastrostomy (PEG) is often indicated in these patients. PEG insertion is normally performed with sedation. Some guidelines withhold sedation in MND patients, due to the risk of respiratory complications. These guidelines seem to be defensive however and evidence is lacking. Our aim was to examine periprocedural respiratory complications occurring in MND patients undergoing PEG insertion with propofol sedation. A retrospective monocentre study was conducted in a referral hospital with an experienced PEG team. Patients with MND who underwent PEG insertion with propofol sedation between January 1. 2016 to January 1. 2023 were analysed to identify periprocedural respiratory complications. 46 patients were included. In five patients (10.9%) respiratory adverse events (AE) occurred, of which two serious (4.3%) and four AE (8.7%). Serious AE (SAE) were fatal in both cases: aspiration pneumonia (2.2%) and hypercapnia (2.2%) a few days after insertion. Sedation may have influenced the first case. Respiratory AE consisted of desaturation in two (4.3%), mild aspiration pneumonia in one (2.2%), and apnea in one patient (2.2%). Compared to previous studies respiratory complications and mortality had comparable prevalences.

Association of ketamine use during procedural sedation with oxygen desaturation and healthcare utilisation: a multicentre retrospective hospital registry study

BACKGROUND

We investigated the effects of ketamine on desaturation and the risk of nursing home discharge in patients undergoing procedural sedation by anaesthetists.

METHODS

We included adult patients who underwent procedures under monitored anaesthetic care between 2005 and 2021 at two academic healthcare networks in the USA. The primary outcome was intraprocedural oxygen desaturation, defined as oxygen saturation <90% for ≥2 consecutive minutes. The co-primary outcome was a nursing home discharge.

RESULTS

Among 234,170 included patients undergoing procedural sedation, intraprocedural desaturation occurred in 5.6% of patients who received ketamine vs 5.2% of patients who did not receive ketamine (adjusted odds ratio [ORadj] 1.22, 95% confidence interval [CI] 1.15-1.29, P<0.001; adjusted absolute risk difference [ARDadj] 1%, 95% CI 0.7-1.3%, P<0.001). The effect was magnified by age >65 yr, smoking, or preprocedural ICU admission (P-for-interaction <0.001, ORadj 1.35, 95% CI 1.25-1.45, P<0.001; ARDadj 2%, 95% CI 1.56-2.49%, P<0.001), procedural risk factors (upper endoscopy of longer than 2 h; P-for-interaction <0.001, ORadj 2.91, 95% CI 1.85-4.58, P<0.001; ARDadj 16.2%, 95% CI 9.8-22.5%, P<0.001), and high ketamine dose (P-for-trend <0.001, ORadj 1.61, 95% CI, 1.43-1.81 for ketamine >0.5 mg kg-1). Concomitant opioid administration mitigated the risk (P-for-interaction <0.001). Ketamine was associated with higher odds of nursing home discharge (ORadj 1.11, 95% CI 1.02-1.21, P=0.012; ARDadj 0.25%, 95% CI 0.05-0.46%, P=0.014).

CONCLUSIONS

Ketamine use for procedural sedation was associated with an increased risk of oxygen desaturation and discharge to a nursing home. The effect was dose-dependent and magnified in subgroups of vulnerable patients.

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.

Res-SE-ConvNet: A Deep Neural Network for Hypoxemia Severity Prediction for Hospital In-Patients Using Photoplethysmograph Signal

Determining the severity level of hypoxemia, the scarcity of saturated oxygen (SpO2) in the human body, is very important for the patients, a matter which has become even more significant during the outbreak of Covid-19 variants. Although the widespread usage of Pulse Oximeter has helped the doctors aware of the current level of SpO2 and thereby determine the hypoxemia severity of a particular patient, the high sensitivity of the device can lead to the desensitization of the care-givers, resulting in slower response to actual hypoxemia event. There has been research conducted for the detection of severity level using various parameters and bio-signals and feeding them in a machine learning algorithm. However, in this paper, we have proposed a new residual-squeeze-excitation-attention based convolutional network (Res-SE-ConvNet) using only Photoplethysmography (PPG) signal for the comfortability of the patient. Unlike the other methods, the proposed method has outperformed the standard state-of-art methods as the result shows 96.5% accuracy in determining 3 class severity problems with 0.79 Cohen Kappa score. This method has the potential to aid the patients in receiving the benefit of an automatic and faster clinical decision support system, thus handling the severity of hypoxemia.

Effect of intravenous lidocaine on the ED50 of propofol for inserting gastroscope without body movement in adult patients: a randomized, controlled study

Background

Circulatory and respiratory depression are common  problems that occur in propofol alone sedation during gastroscopy. As a widely used analgesic adjuvant, intravenous lidocaine can reduce the consumption of propofol during Endoscopic retrograde cholangiopancreatography (ERCP) or colonoscopy. However, it is still unknown the median effective dose (ED₅₀) of propofol when combined with lidocaine intravenously. This study aimed to compare the ED₅₀ of propofol with or without intravenous lidocaine for inserting gastrointestinal endoscope successfully.

Methods

Fifty nine patients undergoing gastroscopy or gastrointestinal (GI) endoscopy were randomly divided into control group (Group C, normal saline + propofol) or lidocaine group (Group L, lidocaine + propofol). Patients were initially injected a bolus of 1.5 mg/kg lidocaine in Group L, whereas equivalent volume of 0.9% saline in Group C. Anaesthesia was then induced with a single bolus of propofol in all subjects. The induction dose of propofol was determined by the modified Dixon’s up-and-down method, and the initial dose was 1.5 mg/kg in both groups. The primary outcome was the ED₅₀ of propofol induction dose with or without intravenous lidocaine. The secondary outcomes were the induction time, the first propofol bolus time (FPBT: from MOAA/S score ≤ 1 to first rescue bolus propofol), and adverse events (AEs: hypoxemia, bradycardia, hypotension, and body movements).

Results

Totally, 59 patients were enrolled and completed this study. The ED₅₀ of propofol combined with lidocaine was 1.68 ± 0.11 mg/kg, significantly reduced compared with the normal saline group, 1.88 ± 0.13 mg/kg (P = 0.002). There was no statistical difference in induction time (P = 0.115) and the FPBT (P = 0.655) between the two groups. There was no significantly difference about the AEs between the two groups.

Conclusion

The ED₅₀ of propofol combined with intravenous lidocaine for successful endoscope insertion in adult patients, was 1.68 ± 0.11 mg/kg significantly reduced compared with the control group.

Trial registration

Chinese Clinical Trial Registry, No: ChiCTR2200059450. Registered on 29 April 2022. Prospective registration. http://www.chictr.org.cn.

Effects of intravenous lidocaine on hypoxemia induced by propofol-based sedation for gastrointestinal endoscopy procedures: study protocol for a prospective, randomized, controlled trial

Background

Oxygen-desaturation episodes, blood pressure drops, and involuntary body movement are common problems that occur in propofol-based sedation in the procedure of painless gastrointestinal (GI) endoscopy. As a widely used analgesic adjuvant, intravenous lidocaine can reduce the consumption of propofol during ERCP or colonoscopy. However, it is still unknown how lidocaine affects the incidence of oxygen-desaturation episodes and cardiovascular events, and involuntary movement during painless GI endoscopy. Therefore, we aimed to assess the effectiveness and safety of intravenous lidocaine in propofol-based sedation for GI endoscopy.

Methods

We will conduct a single-center, prospective, randomized, double-blind, saline-controlled trial. A total number of 300 patients undergoing painless GI procedures will be enrolled and randomly divided into the lidocaine group (Group L) and the control group (Group C). After midazolam and sufentanil intravenous injection, a bolus of 1.5 mg/kg lidocaine was immediately injected and followed by a continuous infusion of 4 mg/kg/h in the lidocaine group, whereas the same volumes of saline solution in the control group. Then, propofol was titrated to produce unconsciousness during the procedure. The primary outcome will be the incidence of oxygen-desaturation episodes. Secondary outcomes will be the incidence of involuntary body movement, discomfort symptoms, propofol consumption, endoscopist, and patient satisfaction.

Discussion

Propofol-based deep sedation without intubation is widely used in painless GI endoscopy. However, adverse events such as hypoxemia often occur clinically. We expect to assess the effect of lidocaine on reducing the incidence of oxygen-desaturation episodes, cardiovascular events, and involuntary body movement. We believe that the results of this trial will provide an effective and safe method for painless GI endoscopy.

Trial registration

Chinese Clinical Trial Registry ChiCTR2100053818. Registered on 30 November 2021.

High flow nasal oxygen, procedural sedation, and clinical governance

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