Effectiveness of high-flow nasal cannula oxygen in apneic oxygenation during intubation in high-risk surgical patients: a systematic review protocol.

OBJECTIVE: This review will investigate the effectiveness of high-flow nasal oxygen in apneic oxygenation through safe apnea time and other ventilation parameters in patients at high risk of oxygen desaturation during induction and tracheal intubation for anesthesia management. INTRODUCTION: High-risk surgical patient groups include obese patients, those with suspected or known obstructive sleep apnea, and critically ill patients, who are at risk of rapid oxygen desaturation during intubation. Conventional oxygen administration in induction and intubation of patients undergoing general anesthesia include nasal cannulas, simple face masks, Venturi, buccal oxygenation, bag-valve mask ventilation, and non-invasive ventilation. High-flow nasal oxygen has emerged as a novel technique, and is advantageous because it increases positive end-expiratory pressure and oxygen delivered. INCLUSION CRITERIA: Eligible studies will include high-risk surgical patients aged 18 or above requiring endotracheal intubation in both emergency and elective anesthetic settings. High-risk patients are defined as those with suspected or known obstructive sleep apnea, obesity (BMI > 35), or critically ill patients (scored the American Society of Anesthesiologists classification as 3 or above). METHODS: The review will follow the JBI methodology for systematic reviews of effectiveness. Databases to be searched include MEDLINE, Embase, and Scopus. Reference lists of selected studies will then be hand-searched for additional eligible studies. The primary outcome will be safe apnea time, with secondary outcomes including oxygen and carbon dioxide parameters, and adverse events (eg, gastric distension). Studies will, where possible, be pooled in statistical meta-analyses with data heterogeneity assessed using the standard χ2 and I2 tests. REVIEW REGISTRATION: PROSPERO CRD42022312145.

Peri-colonoscopy Implications of Sodium-Glucose Cotransporter-2 Inhibitor Therapy: A Mini-review of Available Evidence.

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are a class of oral glucose-lowering agents commonly used for the treatment of type 2 diabetes. With increased use, there has been an increase in the incidence of the rare but life-threatening complication of euglycemic diabetic ketoacidosis. A common but underappreciated precipitant is colonoscopy. In this work, we outline the pathophysiology of the interaction between colonoscopy and SGLT2i use, the evidence regarding SGLT2i use in the periprocedural setting and Australian Diabetes Society guidelines.

Airway Management in the Operating Room and Interventional Suites in Known or Suspected COVID-19 Adult Patients: A Practical Review.

Current evidence suggests that coronavirus disease 2019 (COVID-19) spread occurs via respiratory droplets (particles >5 µm) and possibly through aerosol. The rate of transmission remains high during airway management. This was evident during the 2003 severe acute respiratory syndrome epidemic where those who were involved in tracheal intubation had a higher risk of infection than those who were not involved (odds ratio 6.6). We describe specific airway management principles for patients with known or suspected COVID-19 disease for an array of critical care and procedural settings. We conducted a thorough search of the available literature of airway management of COVID-19 across a variety of international settings. In addition, we have analyzed various medical professional body recommendations for common procedural practices such as interventional cardiology, gastroenterology, and pulmonology. A systematic process that aims to protect the operators involved via appropriate personal protective equipment, avoidance of unnecessary patient contact and minimalization of periprocedural aerosol generation are key components to successful airway management. For operating room cases requiring general anesthesia or complex interventional procedures, tracheal intubation should be the preferred option. For interventional procedures, when tracheal intubation is not indicated, cautious conscious sedation appears to be a reasonable approach. Awake intubation should be avoided unless it is absolutely necessary. Extubation is a high-risk procedure for aerosol and droplet spread and needs thorough planning and preparation. As updates and modifications in the management of COVID-19 are still evolving, local guidelines, appraised at regular intervals, are vital in optimizing clinical management.

LMA® Gastro™ Airway for endoscopic retrograde cholangiopancreatography: a retrospective observational analysis.

BACKGROUND: Various airway techniques have been employed for endoscopic procedures, with an aim to optimise patient outcomes by improving airway control and preventing hypoxia whilst avoiding the need for intubation. The LMA® Gastro™ Airway, a novel dual channel supraglottic airway technique, has been described as such a device. Its utility alongside sedation with low flow nasal cannula and general anaesthesia (GA) with intubation for endoscopic retrograde cholangiopancreatography (ERCP) procedures was evaluated. METHODS: Details of all the ERCPs performed in our institution from March 2017 to June 2018 were carefully recorded in the patients' electronic case records. Data on the successful completion of ERCP through LMA® Gastro™ Airway; any difficulty encountered by the gastroenterologists; and adverse events were recorded. Episodes of hypoxia (SpO2 < 92%) and haemodynamic parameters were compared across the three groups: LMA® Gastro™ vs. sedation with low flow nasal cannula vs. GA with an endotracheal tube (ETT). RESULTS: One hundred seventy-seven ERCP procedures were performed during the study period. The LMA® Gastro™ Airway was employed in 64 procedures (36%) on 59 patients. Of these 64 procedures, ERCP was successfully completed with LMA® Gastro™ Airway in 63 (98%) instances, with only one case requiring conversion to an endotracheal tube. This instance followed difficulty in negotiating the endoscope through LMA® Gastro™ Airway. No episodes of hypoxia or hypercapnia were documented in both LMA® Gastro™ and GA with ETT groups. One sedation case with nasal cannula was noted to have hypoxia. Adverse intraoperative events were recognised in 2 cases of LMA® Gastro™: one had minimal blood stained secretions from the oral cavity that resolved with suctioning; the other developed mild laryngospasm which resolved spontaneously within a few minutes. CONCLUSION: In patients undergoing ERCP, the LMA® Gastro™ airway demonstrated a high success rate for ERCP completion. Ventilation was well maintained with minimal intraoperative and postoperative adverse events. This technique may have a role in higher risk groups such as high ASA (American Society of Anesthesiologists) status, or those with potential airway difficulties such as high body mass index and those with known or suspected sleep apnoea.

High-flow nasal cannula versus standard oxygen therapy assisting sedation during endoscopic retrograde cholangiopancreatography in high risk cases (OTHER): study protocol of a randomised multicentric trial.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is an increasingly common intervention in the treatment of pancreaticobiliary disorders. Patients are often elderly with complex co-morbidities. While monitored anaesthesia care with sedation is commonly used for most cases, few would require general anaesthesia with an endotracheal tube. Both low-flow and high-flow nasal cannulas (HFNC) are established ways of delivering supplemental oxygen, but it is unclear whether one technique is better than the other. HFNC seems a promising tool for advanced procedures but evidence to support its application in high-risk ERCP cases is limited. The rate of oxygen desaturation during endoscopy has been reported to be as high as 11%-50% and the method of oxygen delivery for ERCP merits further study. METHODS/DESIGN: This is a prospective, randomised, multicentre trial comparing the efficacy of oxygen supplementation through HFNC versus low-flow nasal cannula during ERCP, in a cohort of patients at risk of adverse respiratory events. A total of 132 patients will be recruited across three sites and randomly assigned to either the low-flow or the HFNC group. The primary outcome is the proportion of patients experiencing hypoxia, defined by any event of SpO2 < 90%. The secondary outcomes include parameters centred on oxygenation, requirement of airway manoeuvres, successful completion of procedure, perioperative complications, patient satisfaction and cost analysis of the consumables. An intention-to-treat principle will be applied while analysing. DISCUSSION: The demand for ERCPs is likely to increase in the future with the aging population. Our study results may lead to improved outcomes and reduce airway-related complications in patients undergoing ERCPs. The results will be presented at national and international meetings and published in peer-reviewed journals. TRIAL REGISTRATION: www.ANZCTR.org.au, CTRN12619000397112. Registered on 12 March 2019.

The intraoperative use of non-opioid adjuvant analgesic agents: a survey of anaesthetists in Australia and New Zealand.

BACKGROUND: Opioids have long been the mainstay of drugs used for intra-operative analgesia. Due to their well-known short and long term side effects, the use of non-opioid analgesics has often been encouraged to decrease the dose of opioid required and minimise these side effects. The trends in using non-opioid adjuvants among Australian Anaesthetists have not been examined before. This study has attempted to determine the use of non-opioid analgesics as part of an opioid sparing practice among anaesthetists across Australia and New Zealand. METHODS: A survey was distributed to 985 anaesthetists in Australia and New Zealand. The questions focused on frequency of use of different adjuvants and any reasons for not using individual agents. The agents surveyed were paracetamol, dexamethasone, non-steroidal anti-inflammatory agents (NSAIDs), tramadol, ketamine, anticonvulsants, intravenous lidocaine, systemic alpha 2 agonists, magnesium sulphate, and beta blockers. Descriptive statistics were used and data are expressed as a percentage of response for each drug. RESULTS: The response rate was 33.4%. Paracetamol was the most frequently used; with 72% of the respondents describing frequent usage (defined as usage above 70% of the time); followed by parecoxib (42% reported frequent usage) and dexamethasone (35% reported frequent usage). Other adjuvants were used much less commonly, with anaesthetists reporting their frequent usage at less than 10%. The majority of respondents suggested that they would never consider dexmedetomidine, magnesium, esmolol, pregabalin or gabapentin. Perceived disincentives for the use of analgesic adjuvants varied. The main concerns were side effects, lack of evidence for benefit, and anaesthetists' experience. The latter two were the major factors for magnesium, dexmedetomidine and esmolol. CONCLUSION: The uptake of tramadol, lidocaine and magnesium amongst respondents from anaesthetists in Australia and New Zealand was poor. Gabapentin, pregabalin, dexmedetomidine and esmolol use was relatively rare. Most anaesthetists need substantial evidence before introducing a non-opioid adjuvant into their routine practice. Future trials should focus on assessing the opioid sparing benefits and relative risk of using individual non-opioid adjuvants in the perioperative period for specific procedures and patient populations.

Anatomical and ultrasound description of two transmuscular quadratus lumborum block approaches at L2 level and their application in abdominal surgery.

The transmuscular quadratus lumborum (TQL) block is one of the recently evolved myofascial blocks utilised in abdominal surgery. It involves injecting local anaesthetic into the fascial plane anterior to the thoracolumbar fascia. This block has previously been described with a transverse oblique paramedian approach at the L2 level in the sitting position. We describe a TQL block at the same level in the lateral position using a transverse posterolateral approach to provide analgesia for patients undergoing abdominal surgery. We elaborate on these two approaches of TQL block at the L2 level, in relation to the anatomy, sonoanatomy and technical aspects.

Perioperative diabetic ketoacidosis associated with sodium-glucose co-transporter-2 inhibitors: a systematic review.

BACKGROUND: Perioperative diabetic ketoacidosis (DKA) with near-normal blood glucose concentrations, termed euglycaemic ketoacidosis (EDKA), is an adverse effect associated with sodium-glucose co-transporter-2 inhibitors (SGLT2i). Guidelines are still evolving concerning the perioperative management of patients on SGLT2i. We performed a systematic review of published reports of DKA from SGLT2i in the surgical setting to understand better the clinical presentation and characteristics of SGLT2i-associated DKA. METHODS: We searched PubMed, Embase, and ProQuest for reports of perioperative DKA involving SGLT2i up to January 2019. RESULTS: Forty-two reports of EDKA and five cases of hyperglycaemic diabetic ketoacidosis (HDKA) were identified from 33 publications. Canagliflozin was implicated in 26 cases. Presentation time varied from a few hours up to 6 weeks after operation. Precipitating factors may include diabetes medication changes, diet modifications, and intercurrent illnesses. There were 13 cases (12 EDKA and one HDKA) of bariatric surgery, 10 of them noted very-low-calorie diet regimes as a precipitating factor. No precise association between interruption of SGLT2i and the occurrence of DKA could be identified. Seven patients required mechanical ventilation, and acute kidney injury was noted in five. Five cases needed imaging to rule out anastomotic leak and pulmonary embolism, all of them revealed negative findings. Outcome data were available in 32 cases, all of them recovered completely. CONCLUSIONS: EDKA is likely to be under-recognised because of its atypical presentation and may delay the diagnosis. Understanding this clinical entity, vigilance towards monitoring plasma/capillary ketones helps in early identification and assists in the management.

Effects of esmolol on QTc interval changes during tracheal intubation: a systematic review.

INTRODUCTION AND AIMS: Esmolol is an ultra-short-acting ß1 antagonist that has been shown to attenuate the corrected QT (QTc) interval prolongation associated with laryngoscopy and endotracheal intubation (LTI). Prolongation of the QTc interval can precipitate arrhythmias, the most serious of which is torsades de pointes . The aim of this systematic review was to compare esmolol and placebo on QTc changes occurring during LTI. MATERIALS AND METHODS: PubMed, EMBASE, Cochrane Registry of Clinical Trials and CINAHL databases (up to August 2018) were screened for randomised controlled trials comparing esmolol and placebo on QTc changes during LTI in cardiac and non-cardiac surgeries. The primary outcome was QTc changes during LTI and secondary outcome was related to adverse effects from esmolol such as bradycardia and hypotension. RESULTS: Seven trials were identified involving 320 patients, 160 patients receiving esmolol or placebo apiece. A shortening of the QTc post-LTI was evident in the esmolol group compared with the placebo in four studies. Compared with the baseline, the QTc was reduced post-LTI in the esmolol group. In the placebo group, the QTc was prolonged compared with the baseline post LTI. Nonetheless, esmolol did not prevent QTc prolongation in the remaining three studies, and much of this was attributed to employing QTc prolonging agents for premedication and anaesthetic induction. No significant adverse events were noted. CONCLUSION: Compared with placebo, esmolol reduced the LTI-induced QTc prolongation when current non-QTc prolonging agents were chosen for tracheal intubation. Future studies should explore whether transmural dispersion (a marker of torsadogenicity) is also affected during LTI by analysing parameters such as the Tp-e interval (interval between the peak to the end of the T-wave) and Tp-e/QTc (rate corrected Tp-e interval). TRIAL REGISTRATION NUMBER: CRD42018090282.

Continuous transversus abdominis plane block vs intermittent bolus for analgesia after abdominal surgery: a randomized trial.

BACKGROUND: Continuous and intermittent bolus techniques of transversus abdominis plane (TAP) blocks have been used for analgesia after abdominal surgery. Although both are effective, there are no studies comparing them. The aim of this study is to compare analgesia and cost-effectiveness between these groups. METHODS: After obtaining ethical approval, 20 American Society of Anesthesiologists ASA grade I to III patients undergoing elective abdominal surgery were recruited with 10 patients allocated to each arm. Bilateral ultrasound-guided TAP blocks were performed with an initial bolus of 0.5% ropivacaine 20 mL per side, followed by catheter insertion. After surgery, the continuous infusion group received 0.2% ropivacaine 8 mL/hour on each side and the intermittent bolus group received doses of 0.2% ropivacaine 20 mL per side every 8 hours for 48 hours. Both groups received intravenous fentanyl patient-controlled analgesia and regular oral paracetamol. Parameters recorded included numerical rating scores for pain and post-operative analgesic consumption at baseline (time 0) and at 1 hour, 1 day and 2 days post-operatively. The duration of catheter insertion, complications, patient satisfaction and information regarding costs were also recorded. Patient satisfaction was assessed utilizing a 4-point "Likert" scale on day 2 and on day 30. Pain and Likert scores were analysed by non-parametric sum rank test and all two-sampled t-tests assumed unequal variances. RESULTS: There was no difference between duration of TAP block, anesthetic and surgical technique and length of stay (p=0.23). Primary outcomes: pain scores at rest and cough were not significantly different (p=0.20) between the groups. Satisfaction scores were similar at day 2 and 30 (p=0.77). However, the bolus group was more cost-effective (AU$347.98 vs AU$429.43). CONCLUSION: Continuous or bolus TAP blocks are effective analgesic techniques in abdominal surgery, with bolus technique being more economical.