Assessment of ultrasound guided erector spinae plane block for early post-operative analgesia for modified radical mastectomy: a prospective, randomized, controlled study

Erector spinae plane block is a recently introduced block with a wide range of indications. The aim of the present study was to assess the efficacy and safety of ultrasound-guided erector spinae plane block on early post-operative pain relief in patients undergoing modified radical mastectomy. We conducted a prospective, randomized, controlled study in a tertiary care institute. Sixty-five patients were enrolled. Final analysis was performed on 58 patients randomized into two groups. Ultrasound-guided erector spinae plane block with 25 mL of 0.25% bupivacaine was given using a 18 gauge needle. No block was given in the other group. All patients received general anesthesia. Primary outcome measure was 24-hour analgesic consumption. Secondary outcome measures included intra-operative fentanyl consumption, time to first analgesic request, Visual Analog Scale score, nausea score, sedation score, wound quality and patient satisfaction score. Post-operative additional analgesics and intra-operative fentanyl were significantly reduced in patients receiving erector spinae plane block. Time to rescue analgesia was significantly delayed. Visual Analog Scale score was significantly lower at all time intervals. Post-operative nausea at various time intervals was also less. Patient satisfaction score was also noted on a 5-point scale and there was a statistical significant difference. We concluded that erector spinae plane block is a safe technique and provides good analgesia in breast surgery.

The effectiveness of transnasal high flow nasal cannula in bronchoscopy under sedation: a systematic review and meta-analysis

Background

The objective of this study was to conduct a systematic review and meta-analysis of the clinical application effects of transnasal high flow nasal cannula compared to other conventional modalities for oxygen therapy devices in patients undergoing bronchoscopy.

Methods

A comprehensive literature search was conducted in multiple English databases, including PubMed, Web of Science, and Cochrane Library, to collect relevant studies on the application of high flow nasal cannula in patients undergoing bronchoscopy, and conducted a meta-analysis utilizing RevMan 5.4 software, following the predetermined inclusion and exclusion criteria.

Results

A total of 12 studies meeting the inclusion criteria were included, involving 1,631 patients (HFNC group: n = 811, other oxygen therapy group: n = 820). The meta-analysis results demonstrated that HFNC significantly reduced the incidence of hypoxemia and improved the minimum oxygen saturation compared to conventional oxygen therapy (RR = 0.27, 95% CI: 0.18-0.41, p < 0.00001; MD = 6.09, 95% CI: 3.73-8.45, p < 0.00001). Furthermore, HFNC showed statistically significant differences when compared to non-invasive ventilation in terms of hypoxemia incidence (RR = 3.52, 95% CI: 1.13-10.97, p = 0.03) and minimum oxygen saturation (MD = -1.97, 95% CI: -2.97--0.98, p < 0.0001). In addition, HFNC resulted in significantly shorter surgical time and higher PaO2 at the end of the procedure compared to conventional oxygen therapy (MD = 1.53, 95% CI: 0.66-2.40, p = 0.0006; MD = 15.52, 95% CI: 10.12-20.92, p < 0.00001). However, there were no statistically significant differences observed in PaCO2, EtCO2, and MAP at the end of the procedure (MD = 1.23, 95% CI: -0.74-3.20, p = 0.22; MD = -0.35, 95% CI: -3.77-3.06, p = 0.84; MD = -0.54, 95% CI: -2.44-1.36, p = 0.58).

Conclusion

When HFNC or NIV is utilized during the examination and treatment of bronchoscopy patients, both oxygenation modalities enhance oxygenation function and reduce the incidence of hypoxemia compared to conventional oxygen therapy. HFNC can be regarded as a viable alternative to NIV for specific high-risk patients undergoing bronchoscopy. It decreases the duration of bronchoscopy and improves the PaO2 levels at the end of the procedure, but does not significantly impact the PaCO2, EtCO2, and mean arterial pressure.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier 1414374462@qq.com.

A preclinical study on online monitoring of exhaled ciprofol concentration by the ultraviolet time-of-flight spectrometer and prediction of anesthesia depth in beagles

BACKGROUND

Exhaled air has been demonstrated as a reliable medium for monitoring propofol concentration. However, online monitoring of exhaled ciprofol have not been reported.

METHODS

Thirty-six beagles undergoing mechanical ventilation were divided into 6 groups, including bolus injection of low (Group BL, n = 6), medium (Group BM, n = 6), and high dose of ciprofol (Group BH, n = 6) groups; as well as 1 h continuous infusion of low (Group IL, n = 6), medium (Group IM, n = 6), and high dose of ciprofol (Group IH, n = 6) groups. The ciprofol concentration in exhaled air (CE) was determined by the ultraviolet time-of-flight mass spectrometer (UV-TOFMS). The correlations of CE and plasma concentration (Cp), CE and the bispectral index (BIS) were explored. Additionally, the pharmacokinetics (PK) models of CE and Cp, the pharmacodynamics (PD) models of CE and BIS were also established.

RESULTS

Online monitoring of exhaled ciprofol can be achieved with the UV-TOFMS instrument. The CE of ciprofol in beagles was found at parts per billion by volume (ppbv) level. The linear correlation of CE and Cp was weak in bolus injection groups (R2 = 0.01) nonetheless moderate in continuous infusion groups (R2 = 0.53). The i.v. bolus PK model of CE and Cp can be fitted with the non-compartment models. Additionally, the the PD models of CE and BIS can be well fitted with the inhibitory sigmoid Emax model with the estimate values of IC50 = 0.05 ± 0.01 ppbv, γ = 4.74 ± 1.51, E0 = 81.40 ± 3.75, Imax = 16.35 ± 4.27 in bolus injection groups; and IC50 = 0.05 ± 0.01 ppbv, γ = 6.92 ± 1.30, E0 = 83.08 ± 1.62, Imax = 12.58 ± 1.65 in continuous infusion groups.

CONCLUSIONS

Online monitoring of exhaled ciprofol concentration in beagles can be achieved with the UV-TOFMS instrument. Good correlations can be observed between exhaled ciprofol concentration and its cerebral effects reflected by the BIS value, demonstrating the potential of exhaled ciprofol monitoring for titrating depth of anesthesia in future clinical setting.

Clinical effectiveness and safety of intraoperative methadone in patients undergoing laparoscopic hysterectomy: a randomised, blinded clinical trial

Background

Laparoscopic hysterectomy is often carried out as day-stay surgery. Minimising postoperative pain is therefore of utmost importance to ensure timely discharge from hospital. Methadone has several desirable pharmacological features, including a long elimination half-life. Therefore, a single intraoperative dose could provide long-lasting pain relief.

Methods

Patients scheduled to undergo laparoscopic hysterectomy were randomly allocated to receive methadone (0.2 mg kg-1) or morphine (0.2 mg kg-1) intraoperatively, 60 min before tracheal extubation. Primary outcomes were opioid consumption (oral morphine equivalents in milligrams) at 6 and 24 h. Secondary outcomes included pain intensity at rest and during coughing, patient satisfaction, postoperative nausea and vomiting, and adverse events up to 72 h after completion of surgery.

Results

The postoperative median opioid consumption was reduced in the methadone group compared with the morphine group at 6 h (35.5 [0-61] mg vs 48 [31-74.5] mg; P=0.01) and 24 h (42 [10-67] mg vs 54.5 [31-83] mg; P=0.03). On arrival at the PACU, pain at rest was significantly lower in patients receiving methadone (numeric rating scale: 3 [2-5] vs 5 [3-6]), whereas pain scores at rest and coughing were not significantly different throughout the rest of the observation period. No differences in other secondary outcomes were found.

Conclusions

In this randomised, blinded, controlled trial, opioid consumption was reduced during the first 24 postoperative hours in patients receiving methadone without causing an increase in adverse events. The difference observed might be considered as small and of limited clinical relevance.

Clinical trial registration

NCT03908060; EudraCT no. 2018-004351-20.

Application of high-flow nasal cannula in fibreoptic bronchoscopy after congenital heart surgery: a retrospective cohort study

BACKGROUND

The purpose of this study was to compare the effectiveness and safety of high-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) in fibreoptic bronchoscopy (FB) after congenital heart surgery (CHS) in children.

METHODS

We did a retrospective cohort study using patients from the electronic medical record system of Fujian Children's Hospital in China. The study population was children who underwent FB in the cardiac intensive care unit after CHS for 1 year (May 2021-May 2022). Children were classified into HFNC and COT groups according to their oxygen therapy during FB. The primary outcome was oxygenation indices during FB, including pulse oximeter oxygen saturation (SpO2) and transcutaneous oxygen tension (TcPO2) during FB. Secondary outcomes were the number of interruptions during FB and their causes, and complications after FB.

RESULTS

We identified 107 children from the electronic medical record system, and 102 children after CHS were finally included in the study (53 in the HFNC group and 49 in the COT group). During the FB examination, TcPO2 and SpO2 were significantly higher in the HFNC group than in the COT group (TcPO2: 90.3±9.3 vs 80.6±11.1 mm Hg; SpO2: 95.6±2.5 vs 92.1%±2.0%, p<0.001) and the transcutaneous carbon dioxide tension was significantly lower than in the COT group (39.6±3.0 vs 43.5±3.9 mm Hg, p<0.001). During the FB, a total of 20 children in the COT group had 24 interruptions, and 8 children in the HFNC group had 9 interruptions (p=0.001). In terms of postoperative complications, eight cases had complications in the COT group and four complications in the HFNC group (p=0.223).

CONCLUSIONS

Among children undergoing FB after CHS, the application of HFNC was associated with better oxygenation and fewer procedural interruptions compared with COT, without an increased risk of postoperative complications.

Outcomes and evaluation of endoscopic retrograde cholangiopancreatography via Gastro-Laryngeal Tube in adult patients: a prospective randomised control study

OBJECTIVES

In conventional endoscopic retrograde cholangiopancreatography (ERCP), the patient lies prone or in a semi-prone position under deep sedation and maintains spontaneous ventilation. Sedative-induced respiratory depression and unprotected airway compromise patients' safety. The gastro-laryngeal tube (G-LT) is a novel reusable supraglottic airway device with two separate ports for endoscopy and ventilation. This study attempts to evaluate the performance characteristic of G-LT.

METHODS

One hundred and forty patients undergoing ERCP were enrolled and randomized. In Group G, patients underwent ERCP with G-LT, whereas Group S patients underwent ERCP conventionally. G-LT insertion attempts, esophageal visualization times, vital parameters, propofol consumption, endoscopists' and anesthesiologists' satisfaction scores, time to achieve Modified Aldrete Score of ≥ 9, and complications were recorded.

RESULTS

Both groups showed similar demographic parameters and 100% procedure completion rates. G-LT group showed shortened esophageal visualization times (4.71 ± 1.687 s vs 7.37 ± 1.515 s) and increased propofol consumption (423.14 ± 106.982 mg vs 178.00 ± 100.125 mg). Group G showed better endoscopic maneuvrability and lesser hemodynamic variability. Sore throat, dysphagia, and mucosal trauma were higher in the G-LT group.

CONCLUSION

G-LT provides less intra-procedural hemodynamic changes, quicker esophageal visualization, and better scope maneuvrability at the cost of higher propofol consumption, sore throat, dysphagia, and mucosal trauma.

TRIAL REGISTRATION

Clinical Trial Registry of India CTRI/2021/06/034212 (Registered on: 14/06/2021).

The Evolution of Sedation for Pediatric Gastrointestinal Endoscopy

Sedation for pediatric endoscopy has evolved from an endoscopist-administered component of procedures to an almost entirely anesthesiologist-supported endeavor. Nevertheless, there are no ideal endoscopist or anesthesiologist-administered sedation protocols, and wide practice variation exists in both models. Furthermore, sedation for pediatric endoscopy, whether administered by endoscopists or anesthesiologists, remains the highest risk to patient safety. This underscores the importance of both specialties identifying best sedation practices together that can safeguard patients while maximizing procedural efficiency and minimizing costs. In this review, the authors discuss specific levels of sedation for endoscopy and the risks and benefits of various regimens.

Reduction in postoperative sore throat by preoperative nebulization with dexmedetomidine, ketamine or saline: A prospective, randomized-controlled trial

Background and Aims

Postoperative sore throat (POST) is a minor but distressing complication following general anesthesia. The current literature on the effect of preoperative nebulization with dexmedetomidine, or ketamine on POST is, however, sparse. So, we compared the effect of preoperative nebulization with these drugs on POST.

Material and Methods

One hundred and thirty-two American Society of Anaesthesiology (ASA) grade I-II patients undergoing elective laparoscopic surgeries under general anesthesia were randomized into three equal groups: D, K, or C to receive dexmedetomidine, ketamine, or saline as preoperative nebulization, respectively. The primary objective was to compare the incidence and severity of POST, as inferred from the patient interviews at 2, 6, 12, 24-h postoperatively.

Results

Group D had a significantly lower incidence (29.5%) and severity (12: mild; 1: moderate) of POST compared to group K (54.5% [21: mild; 3: moderate]) and group C (56.8% [19: mild; 6: moderate]), at 2-h postoperatively. The same trend was observed at 6-h postoperatively (group D: 22.7% [9: mild; 1: moderate]); group K: (40.9% [17: mild; 1: moderate]); group C (50% [17: mild; 5: moderate]). The mean arterial pressure was significantly lower in group D at 15 min intraoperatively (84.09 mmHg, P = 0.018) and immediate postoperatively (97.60 mmHg, P = 0.034). The postoperative sedation, nausea, and vomiting was not statistically significant.

Conclusion

Preoperative nebulization with dexmedetomidine is effective in the reduction of the incidence and severity of early POST.

Comparing the Safety and Effectiveness of Ketamine Versus Benzodiazepine/Opioid Combination for Procedural Sedation in Emergency Medicine: A Comprehensive Review and Meta-Analysis

Procedural sedation is essential in the ED to conduct painful procedures effectively. Ketamine and benzodiazepines/opioids are commonly used, with ketamine providing adequate analgesia and preserving airway muscle tone. However, ketamine is associated with adverse effects while benzodiazepines/opioids can lead to respiratory depression. This study compares the safety and efficacy of ketamine and midazolam/fentanyl. Two search methods were used to identify studies related to our topic, including a database search and a manual search involving screening reference lists of articles retrieved by the database search. A methodological quality appraisal was conducted on the articles suitable for inclusion using Cochrane's risk of bias tool in the Review Manager software (Review Manager (RevMan) (Computer program). Version 5.4, The Cochrane Collaboration, 2020). Moreover, pooled analysis was performed using the Review manager software. The study analyzed 1366 articles, of which seven were included for analysis. Pooled data showed that ketamine and midazolam/fentanyl had similar effects on pain scores during procedures and sedation depth measured by the University of Michigan sedation scale. However, the Modified Ramsay Sedation Score showed significantly more profound sedation in the ketamine group. The only significant adverse events were vomiting and nausea, which had a higher incidence in the ketamine group. Our data suggest that ketamine is as effective as the midazolam/fentanyl combination for procedural sedation but is associated with higher incidences of adverse events. Therefore, midazolam/fentanyl can be recommended for procedural sedation in the ED. However, it should be provided in the presence of a physician comfortable with airway management due to high incidences of oxygen desaturation.

Comparison of cerebral metabolic rate of oxygen, blood flow, and bispectral index under general anesthesia

SIGNIFICANCE

The optical measurement of cerebral oxygen metabolism was evaluated.

AIM

Compare optically derived cerebral signals to the electroencephalographic bispectral index (BIS) sensors to monitor propofol-induced anesthesia during surgery.

APPROACH

Relative cerebral metabolic rate of oxygen ( rCMRO 2 ) and blood flow (rCBF) were measured by time-resolved and diffuse correlation spectroscopies. Changes were tested against the relative BIS (rBIS) ones. The synchronism in the changes was also assessed by the R-Pearson correlation.

RESULTS

In 23 measurements, optically derived signals showed significant changes in agreement with rBIS: during propofol induction, rBIS decreased by 67% [interquartile ranges (IQR) 62% to 71%], rCMRO 2 by 33% (IQR 18% to 46%), and rCBF by 28% (IQR 10% to 37%). During recovery, a significant increase was observed for rBIS (48%, IQR 38% to 55%), rCMRO 2 (29%, IQR 17% to 39%), and rCBF (30%, IQR 10% to 44%). The significance and direction of the changes subject-by-subject were tested: the coupling between the rBIS, rCMRO 2 , and rCBF was witnessed in the majority of the cases (14/18 and 12/18 for rCBF and 19/21 and 13/18 for rCMRO 2 in the initial and final part, respectively). These changes were also correlated in time ( R > 0.69 to R = 1 , p - values < 0.05 ).

CONCLUSIONS

Optics can reliably monitor rCMRO 2 in such conditions.

Segmental Thoracic Spinal Anesthesia for Laparoscopic Cholecystectomy with the "Hypobaric" Technique: A Case Series

Purpose

Several studies have applied lumbar spinal anesthesia (SA) with isobaric/hyperbaric bupivacaine and opioids in elective laparoscopic cholecystectomy (LC), documenting a superiority of the methodic over general anesthesia (GA) in terms of perioperative pain, nausea, and vomiting, though with a notable incidence of intraoperative right shoulder pain, potentially responsible for conversion to GA. This case series presents an opioid-free scheme of segmental thoracic spinal anesthesia (STSA) with hypobaric ropivacaine, reporting its benefits mainly in terms of shoulder pain occurrence.

Patients and Methods

Hypobaric STSA was performed in nine patients undergoing elective LC between May 1 and September 1, 2022. The level of the needle insertion was included between T8 and T9, via a median or a paramedian approach. Midazolam (0.03 mg/kg) and Ketamine (0.3 mg/kg) were used as adjuvants for intrathecal sedation, followed by the administration of hypobaric ropivacaine 0.25% at a dose of 5 mg and then isobaric ropivacaine at a dose of 10 mg. Patients were placed in anti-Trendelenburg position for the entire duration of surgery. LC was conducted through the standard 3 or 4 ports technique with pneumoperitoneum maintained at a pressure of 8-10 mmHg.

Results

Mean patient age was 75.7 (±17.5) years, with a mean ASA score and Charlson comorbidity index (CCI) of 2.7 (±0.7) and 4.9 (±2.7), respectively. STSA was completed without complications in all patients, with no need for conversion to GA. Mean operative time and SA duration were 37.5 (±8.7) and 145.2 (±21.8) min, respectively. Intraoperatively, no shoulder or abdominal pain and nausea were reported, with only four and two patients requiring vasopressor and sedative intravenous drugs, respectively. Postoperatively, overall mean VAS pain score and within the first 12 hafter surgery were 3 (±2) and 4 (±2), respectively. Median length of stay was 2 (range = 1-3) days.

Conclusion

Hypobaric opioid-free STSA appears to be a promising approach for laparoscopic surgeries, with minimal to null occurrence of shoulder pain. Larger prospective studies are required to validate these findings.

Perioperative Outcomes of Immersive Virtual Reality as Adjunct Anesthesia in Primary Total Hip and Knee Arthroplasty

Background

Immersive virtual reality (IVR) is utilized as an adjunct to anesthesia to distract patients from their intraoperative environment, thereby potentially reducing sedative and narcotic medication usage. This study evaluated intraoperative and acute postoperative results of patients undergoing primary total hip (THA) and total knee arthroplasty (TKA) with and without IVR.

Methods

Utilizing IVR as an adjunct to spinal anesthesia, 18 primary THAs (n = 8) and TKAs (n = 10) were performed. These cases were 1:2 matched based on procedure type, age, sex, and body mass index to those performed without IVR. Intraoperative and postanesthesia care unit sedative/narcotic usage, vital signs, and pain scores were compared. Acute perioperative outcomes, including 24-hour oral morphine equivalent (OME), first ambulation distance, length of stay, and 30-day complications, were also analyzed. Pearson Chi-square and Wilcoxon-Mann-Whitney tests evaluated categorical and continuous variables, respectively.

Results

When compared to non-IVR primary THAs and TKAs, those performed with IVR utilized significantly less intraoperative sedation (48 mg vs 708 mg of propofol; P < .001) and trended toward less narcotic usage (13 mcg vs 39 mcg of fentanyl; P = .07). In the postanesthesia care unit, IVR and non-IVR patients showed no significant differences (P > .3) in vital signs, pain scores, or OME received. Additionally, similar (P > .3) postoperative outcomes were noted in both cohorts’ 24-hour OME use, distance at first ambulation, length of stay, and 30-day complications.

Conclusions

The use of spinal anesthesia with the IVR adjunct to perform primary THAs and TKAs appears to be well-tolerated and associated with less intraoperative sedative medication usage than spinal anesthesia alone.

Opioid-Free Segmental Thoracic Spinal Anesthesia with Intrathecal Sedation for Breast and Axillary Surgery: Report of Four Cases

Purpose

Few studies have described segmental thoracic spinal anesthesia (STSA) as primary anesthesiologic method in breast and axillary surgery, documenting the association of intrathecal local anesthetics and opioids. This case series reports an opioid-free scheme of STSA in four elderly patients undergoing major breast and axillary oncological surgery.

Patients and Methods

STSA was performed in three female patients undergoing unilateral mastectomy ± axillary lymph node dissection (ALND) or sentinel lymph node biopsy for invasive ductal carcinoma and in one male patient undergoing ALND for melanoma metastases. The level of needle insertion was included between T6-8, via a median or paramedian approach. Midazolam (2 mg) and ketamine (20 mg) were used as adjuvants for intrathecal sedation, followed by the administration of hypobaric ropivacaine 0.25% at a dose of 8 mg. The level of sensory blockade achieved was comprised between C2-3 and T11-12. Postoperative analgesia was maintained through continuous intravenous administration of Ketorolac by an elastomeric pump (90 mg over 24 hrs.).

Results

Spinal anesthesia was completed without complications in all patients. Conversion to general anesthesia (GA) and perioperative intravenous sedation were not required. No major postoperative complications and no episodes of postoperative nausea and vomiting (PONV) were reported. No rescue analgesic was administered. All patients were discharged in postoperative day 2 and are alive at 30, 29, 27 and 13 months after surgery, respectively. High grade of satisfaction on the anesthesiologic method was expressed by all cases.

Conclusion

STSA with local anesthetic plus midazolam and ketamine might be considered a safe and effective alternative to GA, even in surgeries involving the breast and axillary region, particularly in elderly and frail patients. Larger prospective studies are required to validate these findings.

Academy of Medicine, Singapore clinical guideline on the use of sedation by non-anaesthesiologists during gastrointestinal endoscopy in the hospital setting

INTRODUCTION

In Singapore, non-anaesthesiologists generally administer sedation during gastrointestinal endoscopy. The drugs used for sedation in hospital endoscopy centres now include propofol in addition to benzodiazepines and opiates. The requirements for peri-procedural monitoring and discharge protocols have also evolved. There is a need to develop an evidence-based clinical guideline on the safe and effective use of sedation by non-anaesthesiologists during gastrointestinal endoscopy in the hospital setting.

METHODS

The Academy of Medicine, Singapore appointed an expert workgroup comprising 18 gastroenterologists, general surgeons and anaesthesiologists to develop guidelines on the use of sedation during gastrointestinal endoscopy. The workgroup formulated clinical questions related to different aspects of endoscopic sedation, conducted a relevant literature search, adopted Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology and developed recommendations by consensus using a modified Delphi process.

RESULTS

The workgroup made 16 recommendations encompassing 7 areas: (1) purpose of sedation, benefits and disadvantages of sedation during gastrointestinal endoscopy; (2) pre-procedural assessment, preparation and consent taking for sedation; (3) Efficacy and safety of drugs used in sedation; (4) the role of anaesthesiologist administered sedation during gastrointestinal endoscopy; (5) performance of sedation; (6) post-sedation care and discharge after sedation; and (7) training in sedation for gastrointestinal endoscopy for non-anaesthesiologists.

CONCLUSION

These recommendations serve to guide clinical practice during sedation for gastrointestinal endoscopy by non-anaesthesiologists in the hospital setting.

The Effectiveness of Capnography Versus Pulse Oximetry in Detecting Respiratory Adverse Events in the Postanesthesia Care Unit (PACU): A Narrative Review and Synthesis

PURPOSE

The objective of this review was to evaluate the effectiveness of capnography monitoring versus standard monitoring of pulse oximetry in detecting respiratory adverse events in nonintubated pediatric and adult postanesthesia care unit (PACU) patients.

DESIGN

Experimental, quasi-experimental, and observational studies examining pulse oximetry and capnography in adult and pediatric patients in the PACU were included in this systematic review.

METHODS

An initial search of MEDLINE and CINAHL, PubMed, Web of Science, Prospero, Google Scholar, and Cochrane was undertaken to identify articles on the topic. The text words contained in the titles and abstracts of relevant articles, and the index terms used to describe the articles were used to develop a full search strategy in July 2019. Reference lists of studies included at critical appraisal stage were hand-searched. Studies published in English from 1978 onward were included.

FINDINGS

Meta-analysis was not possible due to variation in outcome measurements; therefore, results are presented in narrative form. Four studies were included in the review: 1 randomized controlled trial (RCT) and 3 observational cross-sectional studies. The RCT was considered of moderate to high quality, and the observational cross-sectional studies were of high quality. The main findings of this review suggest that there is limited high-quality evidence that capnography improves detection of respiratory adverse events in the PACU versus pulse oximetry.

CONCLUSIONS

The lack of RCTs and varied outcomes measures in the 4 studies reviewed meant that meta-analysis was not possible. Early detection of respiratory adverse events afforded by the addition of PETCO₂ to SpO₂ in the PACU was seen in these studies. More research is needed to determine if widespread implementation of capnography in addition to pulse oximetry would reduce severity of respiratory related adverse events in the PACU through more timely identification.

High-flow nasal oxygenation reduces the risk of desaturation in adults receiving procedural sedation: a meta-analysis of randomized controlled trials

Background

Procedural sedation reduces patients’ discomfort and anxiety, facilitating performance of the examination and intervention. However, it may also cause adverse events, including airway obstruction and hypoxia. We conducted this systematic review and meta-analysis to evaluate the efficacy of high-flow nasal oxygenation (HFNO) compared with that of standard oxygen therapy in adult patients undergoing procedural sedation.

Methods

We identified randomized controlled trials published before November 2020 based on PubMed, Embase, and Cochrane Library databases and ClinicalTrials.gov registry. Intraprocedural desaturation [peripheral oxygen saturation (SpO₂) < 90%] was evaluated as the primary outcome. The secondary outcomes were the lowest SpO₂, need for airway intervention, oxygen therapy-related complications, and patient, operator, and anesthetist’s satisfaction.

Results

Six trials with a total of 2633 patients were reviewed. Patients using HFNO compared with standard oxygen therapy had a significantly lower risk of intraprocedural desaturation [risk ratio 0.18, 95% confidence interval (CI) 0.04-0.87]. The lowest intraprocedural SpO₂ in HFNO group was significantly higher than that in standard oxygen therapy group (mean difference 4.19%, 95% CI 1.74-6.65).

Conclusions

Compared with standard oxygen therapy, HFNO may reduce the risk of desaturation and increase the lowest SpO₂ in adult patients undergoing sedation for medical procedures.

High-flow nasal cannula for reducing hypoxemic events in patients undergoing bronchoscopy: A systematic review and meta-analysis of randomized trials

BACKGROUND

Patients undergoing bronchoscopic procedures may develop hypoxemia and severe complications. High-flow nasal cannula (HFNC) may prevent hypoxemic events during bronchoscopy. We conducted a systematic review of randomized controlled trials (RCTs) to evaluate the effectiveness of HFNC in these patients.

METHODS

We conducted a search in PubMed, Embase, and the Cochrane Library for RCTs published before November 2021. Individual effect sizes were standardized, and a meta-analysis was performed to calculate the pooled effect size using random-effects models. The primary outcome was the incidence of hypoxemic events (oxygen saturation [SpO2] < 90%) during bronchoscopy. Secondary outcomes included the incidence of interrupted bronchoscopy due to desaturation, lowest SpO2 during bronchoscopy, partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (PaCO2), end-tidal CO2 (EtCO2) at the end of bronchoscopy, and the incidence of intubation after the procedure.

RESULTS

Five trials involving 257 patients were reviewed. The incidence of hypoxemic events was lower in the HFNC group than in the conventional oxygen therapy group (risk ratio, 0.25; 95% confidence interval [CI], 0.14-0.42). The lowest SpO2 during the procedure was significantly higher in the HFNC group than in the conventional oxygen therapy group (weighted mean difference [WMD], 7.12; 95% CI, 5.39-8.84). PaO2 at the end of the procedure was significantly higher in the HFNC group than in the conventional oxygen therapy group (WMD, 20.36; 95% CI, 0.30-40.42). The incidence of interrupted bronchoscopy due to desaturation, PaCO2 and EtCO2 at the end of the procedure, and the incidence of intubation after the procedure were not significantly different between groups.

CONCLUSIONS

HFNC may reduce the incidence of hypoxemic events and improve oxygenation in patients undergoing bronchoscopy.

"Awake" Spinal Cord Monitoring Under Local Anesthesia and Conscious Sedation in Fenestrated and Branched Endovascular Aortic Repair

INTRODUCTION

Endovascular repair of thoracoabdominal aortic aneurysms carries a risk of spinal cord ischemia, the causes of which remain uncertain. We hypothesized that local anesthesia (LA) with conscious sedation could abrogate the potential suppressive cardiovascular effects of general anesthesia (GA) and facilitate intraoperative monitoring of neurological function. Here, we examine the feasibility of this technique during fenestrated (FEVAR) or branched endovascular aortic repair (BEVAR).

MATERIALS AND METHODS

Consecutive patients undergoing FEVAR or BEVAR under LA and conscious sedation by a team at a single center were analyzed. Patients received conscious sedation using intravenous remifentanil and propofol infusions in conjunction with a local anesthetic agent. No patient had a prophylactic spinal drain inserted. Outcome measures included conversion to GA, need for vasopressors and/or spinal drainage, length of stay, complications, and patient survival.

RESULTS

A total of 44 patients underwent FEVAR or BEVAR under LA and conscious sedation. The cohort included thoracoabdominal aortic aneurysms (n=41) and pararenal aneurysms treated with endografts covering the supraceliac segment (n=3). Four patients (9%) required conversion to GA at a median operative duration of 198 minutes (range 97-495 minutes). Vasopressors were required intraoperatively in 3 of the cases that were converted to GA. No patient developed spinal cord ischemia and none had insertion of a spinal drain. The median hospital length of stay was 4 days (range 2-41 days). Postoperative delirium and hospital-acquired pneumonia was seen in 7% of patients. All patients survived to 30 days, with 95% alive at a median follow-up of 15 months (range 3-26 months).

CONCLUSION

LA and conscious sedation is a feasible anesthetic technique for the endovascular repair of thoracoabdominal aortic aneurysms.

Intraoperative hypotension and delirium among older adults undergoing transcatheter aortic valve replacement

Background

Postoperative delirium (POD) is a frequently observed complication after transcatheter aortic valve replacement (TAVR). The effects of intraoperative hypotension (IOH) on POD occurrence are currently unclear.

Methods

A retrospective observational cohort study of patients who underwent TAVR was conducted. We predefined IOH as area under the threshold (AUT) of five mean arterial blood pressures (MBP), varying from <100 to <60 mmHg. The AUT consisted of the combination of duration and depth under the MBP thresholds, expressed in mmHg*min. All MBP AUTs were computed based on the complete procedure, independent of procedural phase or duration.

Results

This cohort included 675 patients who underwent TAVR under general anesthesia (n = 128, 19%) or procedural sedation (n = 547, 81%). Delirium occurred mostly during the first 2 days after TAVR, and was observed in n = 93 (14%) cases. Furthermore, 674, 672, 663, 630, and 518 patients had at least 1 min intraoperative MBP <100, <90, <80, <70, and <60 mmHg, respectively. Patients who developed POD had higher AUT based on all five MBP thresholds during TAVR. The penalized adjusted odds ratio varied between 1.08 (99% confidence interval [CI] 0.74–1.56) for the AUT based on MBP < 100 mmHg and OR 1.06 (99% CI 0.88–1.28) for the AUT based on MBP < 60 mmHg.

Conclusions

Intraoperative hypotension is frequently observed during TAVR, but not independently associated with POD after TAVR. Other potential factors than intraoperative hypotension may explain the occurrence of delirium after TAVR.

Audiovisual distraction as an anxiety-minimising adjuvant to regional anaesthesia in adult limb surgery: a service evaluation using patient reported experience measures

Audiovisual distraction (AVD) is an expanding anxiety-minimising technique for patients undergoing surgery under regional anaesthesia (RA). We evaluated patient satisfaction with AVD in the setting of conscious RA for limb surgery using patient reported experience measures (PREMs). Service evaluation using PREMs, via standardised post-operative patient questionnaire, in a single tertiary referral centre for orthopaedic and plastic surgery over an 18-month period. Outcome measures included impact of AVD on peri-operative anxiety, comfort, satisfaction and comparison with previous general anaesthesia (GA) experiences. 50 adult patients undergoing elective limb surgery under RA ± sedation were provided with a wifi-enabled tablet device peri-operatively and completed a post-operative questionnaire regarding their AVD experience. 100% were satisfied with AVD and would recommend to others. 78% were anxious before or during the procedure, of which 97% felt that AVD improved their anxiety levels. Of the 94% with previous experience of GA, 89% reported a 'better' experience with RA + AVD. PREMs regarding AVD were encouraging and lay a foundation for further clinical service development and research into incorporation of this technique for appropriate RA patient groups. Our findings are particularly relevant in the COVID-affected era of anaesthesia as RA benefits and strategies to minimise anxiety are reappraised.

Variation in Pediatric Anesthesiologist Sedation Practices for Pediatric Gastrointestinal Endoscopy

Background: Despite a worldwide shift toward anesthesiologist-administered sedation for gastrointestinal endoscopy in children, ideal sedation regimens remain unclear and best practices undefined. Aim: The aim of our study was to document variation in anesthesiologist-administered sedation for pediatric endoscopy. Outcomes of interest included coefficients of variation, procedural efficiency, as well as adverse events. Methods: IRB approval was obtained to review electronic health records of children undergoing routine endoscopy at our medical center during a recent calendar year. Descriptive and multivariate analyses were used to examine predictors of sedation practices. Results: 258 healthy children [2-21 years (median 15, (Q1-Q3 = 10-17)] underwent either upper and/or lower endoscopies with sedation administered by anesthesiologists (n = 21), using different sedation regimens (29) that ranged from a single drug administered to 6 sedatives in combination. Most patients did not undergo endotracheal tube intubation for the procedure (208, 81%), and received propofol (255, 89%) either alone or in combination with other sedatives. A total of 10 (3.8%) adverse events (9 sedation related) were documented to occur. The coefficient of variation (CV) for sedation times was high at 64.2%, with regression analysis suggesting 8% was unexplained by procedure time. Multivariable model suggested that longer procedure time (p < 0.0001), younger age (p < 0.0001), and use of endotracheal tube intubation (p = 0.02) were associated with longer sedation time. Discussion: We found great variation in anesthesiologist administered regimens for pediatric endoscopy at our institution that may be unwarranted, presenting may opportunities for minimizing patient risk, as well as for optimizing procedural efficiency.

High-flow Nasal Oxygen Versus Standard Oxygen During Flexible Bronchoscopy in Lung Transplant Patients: A Randomized Controlled Trial

BACKGROUND

Diagnostic and interventional flexible bronchoscopy (FB) is increasingly utilized in complex and high-risk patients. Patients are often sedated for comfort and procedure facilitation and hypoxia is commonly observed in this setting. We hypothesized that high-flow nasal oxygen (HFNO) would reduce the incidence of patients experiencing oxygen desaturation.

METHODS

In this randomized controlled trial, postlung transplant patients booked for FB with transbronchial lung biopsy were assigned to either HFNO or low-flow nasal oxygen (LFNO). The patient and bronchoscopist were blinded to group allocation. The primary endpoint was the proportion of patients experiencing mild desaturation [peripheral oxygen saturation (SpO2)<94%]. Secondary endpoints included desaturation (SpO2<90%), the number of airway interventions required and procedure interruptions, the duration of oxygen desaturation and patient, bronchoscopist and anesthesiologist satisfaction scores.

RESULTS

The trial analyzed data from 76 patients (LFNO, n=39; HFNO, n=37). HFNO reduced the proportion of patients experiencing SpO2<94% (43.2% vs. 89.7%, P<0.001) and SpO2<90% (16.2% vs. 69.2%, P<0.001). The FB was interrupted 11 times in 9 patients in the LFNO group, whereas there were no interruptions in the HFNO group. There were no differences in patient and bronchoscopist satisfaction scores between groups, anesthesiologists had higher satisfaction scores when using HFNO (P<0.001).

CONCLUSION

Hypoxia occurred less commonly in postlung transplant patients receiving HFNO during FB. Further studies are warranted in other high-risk populations undergoing longer duration FB.

Artificial intelligence in dermatology and healthcare: An overview

Many aspects of our life are affected by technology. One of the most discussed advancements of modern technologies is artificial intelligence. It involves computational methods which in some way mimic the human thought process. Just like other branches, the medical field also has come under the ambit of artificial intelligence. Almost every field in medicine has been touched by its effect in one way or the other. Prominent among them are medical diagnosis, medical statistics, robotics, and human biology. Medical imaging is one of the foremost specialties with artificial intelligence applications, wherein deep learning methods like artificial neural networks are commonly used. artificial intelligence application in dermatology was initially restricted to the analysis of melanoma and pigmentary skin lesions, has now expanded and covers many dermatoses. Though the applications of artificial intelligence are ever increasing, large data requirements, interpretation of data and ethical concerns are some of its limitations in the present day.

High quantities: Evaluating the association between cannabis use and propofol anesthesia during endoscopy

BACKGROUND

Endoscopy under propofol sedation has become a routine procedure. Given the number of Canadians undergoing an endoscopy annually, as well as the pervasive use of cannabis by many patients, understanding the effect of cannabis use on the propofol dose at endoscopy is highly relevant. We aimed to evaluate the association between cannabis exposure and the propofol dose needed to achieve adequate sedation at endoscopy.

METHODS

A case-control study of individuals undergoing endoscopy was conducted at a single outpatient endoscopy clinic in London, Ontario between 2014 and 2017. Cases included all individuals with any self-reported cannabis exposure, while controls included all individuals without any self-reported history of cannabis use. Dose of propofol administered by a single anesthetist was collected on each subject as well as additional demographic and procedure-related covariates.

RESULTS

Three hundred and eighteen participants were included (cases, n = 151; controls, n = 167). Cannabis exposure was associated with an increase in propofol dose (cases 0.33 mg/kg/minute ±0.24; controls, 0.18 mg/kg/minute ±0.11; p<0.0001). Cannabis exposure remained an independent predictor of propofol dose on multivariate linear regression accounting for other important covariates (p<0.0001). Daily cannabis users required a higher propofol dose than weekly or monthly users. Three procedural sedation-related complications occurred in the cannabis-exposed group, while none occurred in the unexposed group.

CONCLUSION

Our data suggest that cannabis use is significantly associated with the quantity of propofol needed for sedation at endoscopy. Further study is needed to better understand the molecular basis for this possible drug-drug interaction.

Mandibular advancement devices shorten desaturation duration in patients at high risk for obstructive sleep apnea syndrome during intravenous propofol sedation in the decubitus position

BACKGROUND

The purpose of this study was to determine the efficacy of a mandibular advancement device (MAD) for increasing patient safety during sedated total knee arthroplasty (TKA) and total hip replacement (THR).

METHODS

Forty patients undergoing TKA or THR surgery in the supine or lateral recumbent positions under spinal anesthesia were enrolled. Sedation and oxygenation were administered. The MAD (Sweet Sleep Anti-Snoring Device) was then placed after 15 minutes of observation. SpO2, PetCO2, blood pressure, and respiratory rate were recorded.

RESULTS

Sedated patients in the decubitus position had higher saturation nadirs, shorter desaturation durations, shorter airway obstruction durations, and fewer rescue events than those in the supine position. In patients at a high risk of obstructive sleep apnea syndrome (OSAS), desaturation duration, obstruction duration, apnea duration, desaturation duration, and rescue events were significantly lower after MAD placement. However, the saturation nadir did not improve after MAD placement.

CONCLUSION

The MAD may shorten the duration of desaturation events during spontaneous breathing sedative procedures in the lateral recumbent position but not in the supine position. Breathing patterns did not change from nasal breathing to oral breathing or vice versa between pre- and postplacement of the MAD. Sedation score evaluation affects breathing pattern changes from oral breathing to nasal breathing and vice versa.

Predicting Deep Hypnotic State From Sleep Brain Rhythms Using Deep Learning: A Data-Repurposing Approach

BACKGROUND:

Brain monitors tracking quantitative brain activities from electroencephalogram (EEG) to predict hypnotic levels have been proposed as a labor-saving alternative to behavioral assessments. Expensive clinical trials are required to validate any newly developed processed EEG monitor for every drug and combinations of drugs due to drug-specific EEG patterns. There is a need for an alternative, efficient, and economical method.

METHODS:

Using deep learning algorithms, we developed a novel data-repurposing framework to predict hypnotic levels from sleep brain rhythms. We used an online large sleep data set (5723 clinical EEGs) for training the deep learning algorithm and a clinical trial hypnotic data set (30 EEGs) for testing during dexmedetomidine infusion. Model performance was evaluated using accuracy and the area under the receiver operator characteristic curve (AUC).

RESULTS:

The deep learning model (a combination of a convolutional neural network and long short-term memory units) trained on sleep EEG predicted deep hypnotic level with an accuracy (95% confidence interval [CI]) = 81 (79.2–88.3)%, AUC (95% CI) = 0.89 (0.82–0.94) using dexmedetomidine as a prototype drug. We also demonstrate that EEG patterns during dexmedetomidine-induced deep hypnotic level are homologous to nonrapid eye movement stage 3 EEG sleep.

CONCLUSIONS:

We propose a novel method to develop hypnotic level monitors using large sleep EEG data, deep learning, and a data-repurposing approach, and for optimizing such a system for monitoring any given individual. We provide a novel data-repurposing framework to predict hypnosis levels using sleep EEG, eliminating the need for new clinical trials to develop hypnosis level monitors.

Full-endoscopic transpedicular discectomy (FETD) for lumbar herniations: Case report and review of the literature

INTRODUCTION

One of the most challenging occurrences in full-endoscopic surgery for lumbar disc protrusions are up-migrated or down-migrated herniations. Those occurrences are difficult to retrieve with transforaminal or interlaminar approaches.

PRESENTATION OF CASE

We describe our experience in dealing with a right paramedian down-migrated L3-L4 disc herniation. The patient underwent full endoscopic transpedicular endoscopic discectomy (FETD), by reaming the right L4 peduncle for intracanal access and fragment retrieval. We also reviewed the recent literature to summarize the advantages of transpedicular approaches, along with current indications and contraindications for this procedure.

DISCUSSION

We highlighted how FETD is safe and feasible for down-migrated and up-migrated disc herniation showing excellent results in our patient and in the small cohorts of patients already published in the literature.

CONCLUSION

FETD was effective in treating up-migrated and down-migrated disc herniation, as well as discal cysts, showing the feasibility and safety of the technique from any level from L1 to S1.

Identification and evaluation of observational measures for the assessment and/or monitoring of level of consciousness in adult palliative care patients: A systematic review for I-CAN-CARE

BACKGROUND

The use of observational measures to assess palliative care patients' level of consciousness may improve patient care and comfort. However, there is limited knowledge regarding the validity and reliability of these measures in palliative care settings.

AIM

To identify and evaluate the psychometric performance of observational level of consciousness measures used in palliative care.

DESIGN

Systematic review; PROSPERO registration: CRD42017073080.

DATA SOURCES

We searched six databases until November 2018, using search terms combining subject headings and free-text terms. Psychometric performance for each identified tool was appraised independently by two reviewers following established criteria for developing and evaluating health outcome measures.

RESULTS

We found 35 different levels of consciousness tools used in 65 studies. Only seven studies reported information about psychometric performance of just eight tools. All other studies used either ad hoc measures for which no formal validation had been undertaken (n = 21) or established tools mainly developed and validated in non-palliative care settings (n = 37). The Consciousness Scale for Palliative Care and a modified version of the Richmond Agitation-Sedation Scale received the highest ratings in our appraisal, but, since psychometric evidence was limited, no tool could be assessed for all psychometric properties.

CONCLUSION

An increasing number of studies in palliative care are using observational measures of level of consciousness. However, only a few of these tools have been tested for their psychometric performance in that context. Future research in this area should validate and/or refine the existing measures, rather than developing new tools.

Intraoperative methadone for postoperative pain after laparoscopic hysterectomy: Protocol for a randomised, double-blind trial

BACKGROUND

Hysterectomy is often carried out as same-day surgery. Treatment of postoperative pain is, therefore, of utmost importance to ensure timely discharge from hospital. Methadone has several desirable pharmacological features, including a long elimination half-life. Theoretically, a single intraoperative dose could provide long-lasting pain relief.

METHODS

This is a single-centre, investigator-initiated, randomised, double-blind study. Two-hundred and fifty women, scheduled to undergo hysterectomy at Horsens Region Hospital, Denmark, are randomized to receive methadone (0.2 mg/kg) or morphine (0.2 mg/kg) intraoperatively, 60 minutes before extubation. Primary outcomes are opioid consumption at 6 and 24 hours. Secondary outcomes include pain intensity at rest and during coughing at 1, 3, 6, 24 and 48 hours; patient satisfaction at 3 and 24 hours, postoperative nausea and vomiting at 6, 24 and 72 hours, adverse events in the postanaesthesia care unit (PACU) and time until readiness for discharge. Another outcome is persistent abdominal pain after 4 months.

CONCLUSIONS

The study outlined in this protocol will provide important information about the use of methadone in same-day hysterectomy patients. The results will presumably be applicable to other types of surgery involving visceral pain.

Effects site concentrations of propofol using target-controlled infusion in dental treatment under deep sedation among different intellectual disability types

Background

We aimed to assess the dose needed to achieve the propofol effect-site concentration using target-controlled infusion in intellectually disabled patients and to detail the most effective method for achieving a safe level of consciousness without hemodynamic changes as well as detail any resulting adverse effects.

Methods

We performed a retrospective review of sedation service records of 138 intellectually disabled patients (51, mental retardation; 36, autism; 30, brain lesion, 12 genetic diseases, 9 dementia) aged over 15 years and weighing over 30 kg. These patients had received propofol via target-controlled infusion in the special care dental clinic of Seoul National University Dental Hospital from May 2008 to September 2018 for restorative treatment (112), minor surgery (13), prosthodontics (7), periodontics treatment (5), and implant (1).

Results

For all groups, the duration of dental treatments was 43 ± 18 minutes, total sedation time was 73 ± 23 minutes, and total BIS values was 57 ± 12. The propofol maintenance dosage values for each group were: mental retardation, 3 ± 0.5 (2–4) µg/ml; autism, 3.1 ± 0.7 (2–5) µg/ml; brain lesion, 2.8 ± 0.7 (1.5–5) µg/ml; genetic disease, 2.9 ± 0.9 (1–4) µg/ml; and dementia 2.3 ± 0.7 (1–3.4) µg/ml.

Conclusions

The dementia group needed a lower dosage to reach a safe, effective propofol effect-site concentration than the other groups. Since there were no complications, deep sedation is a great alternative to general anesthesia for dental treatment of intellectually disabled patients.

Brain Monitoring of Sedation in the Intensive Care Unit Using a Recurrent Neural Network

Over and under-sedation are common in critically ill patients admitted to the Intensive Care Unit. Clinical assessments provide limited time resolution and are based on behavior rather than the brain itself. Existing brain monitors have been developed primarily for non-ICU settings. Here, we use a clinical dataset from 154 ICU patients in whom the Richmond Agitation-Sedation Score is assessed about every 2 hours. We develop a recurrent neural network (RNN) model to discriminate between deep vs. no sedation, trained end-to-end from raw EEG spectrograms without any feature extraction. We obtain an average area under the ROC of 0.8 on 10-fold cross validation across patients. Our RNN is able to provide reliable estimates of sedation levels consistently better compared to a feed-forward model with simple smoothing. Decomposing the prediction error in terms of sedatives reveals that patient-specific calibration for sedatives is expected to further improve sedation monitoring.

Capnography Monitoring During Procedural Sedation and Analgesia

Procedural sedation is used to alleviate pain and anxiety associated with diagnostic procedures in the acute care setting. Although commonly used, procedural sedation is not without risk. Key to reducing this risk is early identification of risk factors through presedation screening and monitoring during the procedure. Electrocardiogram, respiratory rate, blood pressure, and pulse oximetry commonly are monitored. These parameters do not reliably identify airway and ventilation compromise. Capnography measures exhaled carbon dioxide and provides early identification of airway obstruction and hypoventilation. Capnography is useful in patients receiving supplemental oxygen. In these patients, oxygen desaturation reported by pulse oximetry may lag during episodes of respiratory depression and apnea. Capnography indicates partial pressure of end-tidal carbon dioxide and provides information regarding airway integrity and patterns of ventilation compromise. Implementation of this technology may provide an additional layer of safety, reducing risk of respiratory compromise in patients receiving procedural sedation.

Hypoventilation patterns during bronchoscopic sedation and their clinical relevance based on capnographic and respiratory impedance analysis

Capnography involves the measurement of end-tidal CO₂ (EtCO₂) values to detect hypoventilation in patients undergoing sedation. In a previous study, we reported that initiating a flexible bronchoscopy (FB) examination only after detecting signs of hypoventilation could reduce the risk of hypoxemia without compromising the tolerance of the patient for this type of intervention. We hypothesize that hypoventilation status could be determined with greater precision by combining thoracic impedance-based respiratory signals, RESP, and EtCO₂ signals obtained from a nasal-oral cannula. Retrospective analysis was conducted on RESP and EtCO₂ waveforms obtained from patients during the induction of sedation using propofol for bronchoscopic examination in a previous study. EtCO₂ waveforms associated with hypoventilation were then compared with RESP patterns, patient variables, and sedation outcomes. Signals suitable for analysis were obtained from 44 subjects, 42 of whom presented indications of hypoventilation, as determined by EtCO₂ waveforms. Two subtypes of hypoventilation were identified by RESP: central-predominant (n = 22, flat line RESP pattern) and non-central-predominant (n = 20, RESP pattern indicative of respiratory effort with upper airway collapse). Compared to cases of non-central-predominant hypoventilation, those presenting central-predominant hypoventilation during induction were associated with a lower propofol dose (40.2 ± 18.3 vs. 60.8 ± 26.1 mg, p = 0.009), a lower effect site concentration of propofol (2.02 ± 0.33 vs. 2.38 ± 0.44 µg/ml, p = 0.01), more rapid induction (146.1 ± 105.5 vs. 260.9 ± 156.2 s, p = 0.01), and lower total propofol dosage (96.6 ± 41.7 vs. 130.6 ± 53.4 mg, p = 0.04). Hypoventilation status (as revealed by EtCO₂ levels) could be further classified by RESP into central-predominant or non-central-predominant types. It appears that patients with central-predominant hypoventilation are more sensitive to propofol during the induction of sedation. RESP values could be used to tailor sedation management specifically to individual patients.

Dexmedetomidine and Midazolam Sedation Reduces Unexpected Patient Movement During Dental Surgery Compared With Propofol and Midazolam Sedation

PURPOSE

Owing to its unpredictability, unexpected patient movement is one of the most important problems during surgery while under monitored anesthesia care with sedation. The purpose of this study was to compare unexpected patient movement during dental surgery while under dexmedetomidine and propofol sedation.

MATERIALS AND METHODS

The authors designed and implemented a prospective randomized controlled trial. Patients undergoing dental surgery requiring intravenous sedation were randomly assigned to dexmedetomidine and midazolam (dexmedetomidine group) or propofol and midazolam (propofol group) sedation. In each group, midazolam 0.02 mg/kg was administered in conjunction with continuous administration of dexmedetomidine or propofol to maintain a bispectral index value of 70 to 80. Unexpected patient movement interfering with the procedure was defined as acceptable, defined as no body movement or only 1 controllable movement, or unacceptable, defined as at least 2 controllable movements or any uncontrollable movement. The primary outcome was unexpected patient movement, and the secondary outcome was defined as snoring and cough reflex. Other variables included demographic and procedural characteristics. Continuous or ordinal variables were analyzed using the Student t test or Mann-Whitney test. Dichotomous or categorical variables were analyzed using the χ² test or Fisher exact test. A P value less than.05 was considered statistically significant.

RESULTS

Eighty-eight patients were enrolled in the study (dexmedetomidine group, n = 44; propofol group, n = 44). There were no relevant differences between groups for demographics and baseline variables. Intraoperative unacceptable patient movement occurred more commonly in the propofol group (n = 13; 30%) than in the dexmedetomidine group (n = 4; 9%; P = .015). Intraoperative snoring occurred more commonly in the dexmedetomidine than in the propofol group (P = .045). Incidence and number of cough reflexes were comparable between groups.

CONCLUSION

Dexmedetomidine and midazolam sedation decreases unexpected patient movement during dental surgery compared with propofol and midazolam sedation.

Different effects of propofol and dexmedetomidine sedation on electroencephalogram patterns: Wakefulness, moderate sedation, deep sedation and recovery

Sedation induces changes in electroencephalography (EEG) dynamics. However, the distinct EEG dynamic characteristics at comparable sedation levels have not been well studied, resulting in potential interpretation errors in EEG monitoring during sedation. We aimed to analyze the EEG dynamics of dexmedetomidine and propofol at comparable sedation levels and to explore EEG changes with increased sedation levels for each agent. We measured the Bispectral Index (BIS) and 20-channel EEG under dexmedetomidine and propofol sedation from wakefulness, moderate sedation, and deep sedation to recovery in healthy volunteers (n = 10) in a randomized, 2-day, crossover study. Observer's Assessment of Alertness and Sedation (OAA/S) score was used to assess sedation levels. Despite similar changes in increased delta oscillations, multiple differences in the EEG spatiotemporal dynamics were observed between these two agents. During moderate sedation, both dexmedetomidine and propofol induced increased spindle power; however, dexmedetomidine decreased the global alpha/beta/gamma power, whereas propofol decreased the alpha power in the occipital area and increased the global spindle/beta/gamma power. During deep sedation, dexmedetomidine was associated with increased fronto-central spindle power and decreased global alpha/beta/gamma power, but propofol was associated with increased theta/alpha/spindle/beta power, which was maximized in the frontal area. The transition of topographic alpha/spindle/beta power distribution from moderate sedation to deep sedation completely differed between these two agents. Our study demonstrated that there was a distinct hierarchy of EEG changes with increased sedation depths by propofol and dexmedetomidine. Differences in EEG dynamics at the same sedation level might account for differences in the BIS value and reflect the different sedation mechanisms. EEG-based clinical sedation monitoring should consider the effect of drug types on EEG dynamics.

Procedural sedation in the ICU and emergency department

PURPOSE OF REVIEW

Procedures are increasingly being performed in the acute care setting, outside of the operating rooms (OR). This article aims to review the current literature on out-of-OR procedural sedation with a focus on the ICU and emergency department, highlighting the following topics: multidisciplinary team approach, choice of pharmacologic agent, sedation scales, current safety guidelines, anticipating complications, appropriate monitoring and necessary resources.

RECENT FINDINGS

Subjective assessment of sedation using sedation scales is controversial. Addition of ketamine and dexmedetomidine to propofol for sedation improves patient and proceduralist satisfaction. The short-acting benzodiazepine remimazolam shows promise in initial phase 2 trials. Use of capnography for monitoring during sedation is being challenged by new literature from the emergency department setting. Hypoxia is the most common adverse event with procedural sedation, and the risk of pulmonary aspiration is low.

SUMMARY

Multimodal/synergistic sedation under a multidisciplinary team provides the best patient satisfaction. Collection and analysis of physiological data and outcomes of patients undergoing procedural sedation is necessary to maintain compliance with regulatory bodies. There is a paucity of comprehensive guidelines for conducting research in procedural sedation; therefore, it is being currently addressed by the Sedation Consortium.

Use of computer-assisted drug therapy outside the operating room

PURPOSE OF REVIEW

The number of procedures performed in the out-of-operating room setting under sedation has increased many fold in recent years. Sedation techniques aim to achieve rapid patient turnover through the use of short-acting drugs with minimal residual side-effects (mainly propofol and opioids). Even for common procedures, the practice of sedation delivery varies widely among providers. Computer-based sedation models have the potential to assist sedation providers and offer a more consistent and safer sedation experience for patients.

RECENT FINDINGS

Target-controlled infusions using propofol and other short-acting opioids for sedation have shown promising results in terms of increasing patient safety and allowing for more rapid wake-up times. Target-controlled infusion systems with real-time patient monitoring can titrate drug doses automatically to maintain optimal depth of sedation. The best recent example of this is the propofol-based Sedasys sedation system. Sedasys redefined individualized sedation by the addition of an automated clinical parameter that monitors depth of sedation. However, because of poor adoption and cost issues, it has been recently withdrawn by the manufacturer.

SUMMARY

Present automated drug delivery systems can assist in the provision of sedation for out-of-operating room procedures but cannot substitute for anesthesia providers. Use of the available technology has the potential to improve patient outcomes, decrease provider workload, and have a long-term economic impact on anesthesia care delivery outside of the operating room.

Does this patient need telemetry? An analysis of telemetry ordering practices at an academic medical center

INTRODUCTION

The American Heart Association and Choosing Wisely campaign recommend guideline-based usage of telemetry. Inappropriate use leads to increased costs, alarm fatigue, and inefficient nursing care. This study assesses provider ordering practices for telemetry at a US-based academic hospital.

METHODS

This retrospective study includes all telemetry orders in the medicine and progressive care units from April 2014 to March 2015. Indications were grouped into categories per American Heart Association guidelines.

RESULTS

The top 3 cardiac indications included angina/acute coronary syndrome (35.3%), arrhythmias (19.7%), and heart failure (10.2%). However, noncardiac indications accounted for 20.2% of orders, including respiratory conditions (17.4%), infection (17.4%), substance abuse (14.0%), bleeding (12.4%), vital sign monitoring (10.4%), altered mental status (7.0%), and pulmonary embolus/deep vein thrombosis (7.0%).

CONCLUSIONS

One-fifth of patients were monitored on telemetry for noncardiac indications. We recommend further study on the benefits and risks of telemetry in these patients and systems-based changes for appropriate usage.

A Prospective, Multicenter, Single-Blind Study Assessing Indices of SNAP II Versus BIS VISTA on Surgical Patients Undergoing General Anesthesia

Background

Traditionally, anesthesiologists have relied on nonspecific subjective and objective physical signs to assess patients’ comfort level and depth of anesthesia. Commercial development of electrical monitors, which use low- and high-frequency electroencephalogram (EEG) signals, have been developed to enhance the assessment of patients’ level of consciousness. Multiple studies have shown that monitoring patients’ consciousness levels can help in reducing drug consumption, anesthesia-related adverse events, and recovery time. This clinical study will provide information by simultaneously comparing the performance of the SNAP II (a single-channel EEG device) and the bispectral index (BIS) VISTA (a dual-channel EEG device) by assessing their efficacy in monitoring different anesthetic states in patients undergoing general anesthesia.

Objective

The primary objective of this study is to establish the range of index values for the SNAP II corresponding to each anesthetic state (preinduction, loss of response, maintenance, first purposeful response, and extubation). The secondary objectives will assess the range of index values for BIS VISTA corresponding to each anesthetic state compared to published BIS VISTA range information, and estimate the area under the curve, sensitivity, and specificity for both devices.

Methods

This is a multicenter, prospective, double-arm, parallel assignment, single-blind study involving patients undergoing elective surgery that requires general anesthesia. The study will include 40 patients and will be conducted at the following sites: The Ohio State University Medical Center (Columbus, OH); Northwestern University Prentice Women's Hospital (Chicago, IL); and University of Miami Jackson Memorial Hospital (Miami, FL). The study will assess the predictive value of SNAP II versus BIS VISTA indices at various anesthetic states in patients undergoing general anesthesia (preinduction, loss of response, maintenance, first purposeful response, and extubation). The SNAP II and BIS VISTA electrode arrays will be placed on the patient’s forehead on opposite sides. The hemisphere location for both devices’ electrodes will be equally alternated among the patient population. The index values for both devices will be recorded and correlated with the scorings received by performing the Modified Observer’s Assessment of Alertness and Sedation and the American Society of Anesthesiologists Continuum of Depth of Sedation, at different stages of anesthesia.

Results

Enrollment for this study has been completed and statistical data analyses are currently underway.

Conclusions

The results of this trial will provide information that will simultaneously compare the performance of SNAP II and BIS VISTA devices, with regards to monitoring different anesthesia states among patients.

ClinicalTrial

Clinicaltrials.gov NCT00829803; https://clinicaltrials.gov/ct2/show/NCT00829803 (Archived by WebCite at http://www.webcitation.org/6nmyi8YKO)

Computer-Assisted and Patient-Controlled Sedation Platforms

As the number and complexity of endoscopic procedures increase, the role of sedation has been integral in patient and physician satisfaction. This article discusses the advances of computer-assisted and patient-controlled platforms. These computer-assisted and patient-controlled platforms use different anesthetics and analgesics, all with the intent of achieving improved consistency in the level of sedation, appropriate to the needs of patients, while also improving patient safety. These systems have been around for decades; however, few are approved for use in the United States, and several still require further study before broad clinical application.

Sedation and Monitoring in the Pediatric Patient during Gastrointestinal Endoscopy

Sedation is a fundamental component of pediatric gastrointestinal procedures. The 2 main types of sedation for pediatric endoscopy remain general anesthesia and procedural sedation. Although anesthesiologist-administered sedation protocols are more common, there is no ideal regimen for endoscopy in children. This article discusses specific levels of sedation for endoscopy as well as various regimens that can be used to achieve each. Risks and considerations that may be specific to performing gastrointestinal procedures in children are reviewed. Finally, potential future directions for sedation and monitoring that may change the practice of pediatric gastroenterology and ultimately patient outcomes are examined.

Inhalation of 50% Oxygen Does Not Impair Respiratory Depression During Midazolam Sedation

PURPOSE

To investigate how inhalation of 50% oxygen during intravenous midazolam sedation affects respiratory variables and thus the availability of oxygen.

MATERIALS AND METHODS

Study subjects were 21 healthy adult volunteers (American Society of Anesthesiologists physical status I). They were allocated to undergo midazolam sedation during high-concentration oxygen inhalation (group H) or during normal air inhalation (group N) in a single-blinded randomized crossover design, with an interval of at least 3 days between the 2 sedation sessions. In each experiment, midazolam 0.05 mg/kg was administered, after which the following variables were measured for 40 minutes: oxygen saturation by pulse oximetry (SpO2), end-tidal carbon dioxide partial pressure (ETCO2), respiration rate (RR), tidal volume (VT), and minute volume (MV). Subsequently, flumazenil 0.5 mg was administered, and the same variables were measured for 10 minutes.

RESULTS

SpO2 decreased after midazolam administration in the 2 groups. SpO2 in group H was higher than that in group N at all time points. RR increased and VT decreased after midazolam administration in the 2 groups; however, in contrast to SpO2, the levels of these parameters did not meaningfully differ between groups at any time point. MV remained unchanged in the 2 groups. ETCO2 decreased similarly after midazolam administration in the 2 groups.

CONCLUSION

Inhalation of 50% oxygen during midazolam sedation did not enhance respiratory depression by midazolam. This suggests that high-concentration oxygen inhalation during midazolam sedation could prevent hypoxia.

Depth of anaesthesia monitoring during procedural sedation and analgesia: A systematic review and meta-analysis

OBJECTIVES

Processed electroencephalogram-based depth of anaesthesia monitoring devices provide an additional method to monitor level of consciousness during procedural sedation and analgesia. The objective of this systematic review was to determine whether using a depth of anaesthesia monitoring device improves the safety and efficacy of sedation.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Electronic databases (CENTRAL; Medline; CINAHL) were searched up to May 2015.

REVIEW METHODS

Randomised controlled trials that compared use of a depth of anaesthesia monitoring device to a control group who received standard monitoring during procedural sedation and analgesia were included. Study selection, data extraction and risk of bias assessment (Cochrane risk of bias tool) were performed by two reviewers. Safety outcomes were hypoxaemia, hypotension and adverse events. Efficacy outcomes were amount of sedation used, duration of sedation recovery and rate of incomplete procedures.

RESULTS

A total of 16 trials (2138 participants) were included. Evidence ratings were downgraded to either low or moderate quality due to study limitations and imprecision. Meta-analysis of 8 trials (766 participants) found no difference in hypoxaemia (RR 0.87; 95% CI=0.67-1.12). No statistically significant difference in hypotension was observed in meta-analysis of 8 trials (RR 0.96; 95% CI=0.54-1.7; 942 participants). Mean dose of propofol was 51mg lower for participants randomised to depth of anaesthesia monitoring (95% CI=-88.7 to -13.3mg) in meta-analysis of results from four trials conducted with 434 participants who underwent interventional endoscopy procedures with propofol infusions to maintain sedation. The difference in recovery time between depth of anaesthesia and standard monitoring groups was not clinically significant (standardised mean difference -0.41; 95% CI=-0.8 to -0.02; I²=86%; 8 trials; 809 participants).

CONCLUSIONS

Depth of anaesthesia monitoring did impact sedation titration during interventional procedures with propofol infusions. For this reason, it seems reasonable for anaesthetists to utilise a depth of anaesthesia monitoring device for select populations of patients if it is decided that limiting the amount of sedation would be beneficial for the individual patient. However, there is no need to invest in purchasing extra equipment or training staff who are not familiar with this technology (e.g. nurses who do not routinely use a depth of anaesthesia monitoring device during general anaesthesia) because there is no high quality evidence suggestive of clear clinical benefits for patient safety or sedation efficacy.