Anaesthetic preconditioning and its role in protecting patients at risk of myocardial ischaemia

Ischaemic preconditioning is a phenomenon where prior minor ischaemic events allows organs to better withstand further episodes of ischaemia. Preconditioning downgrades the effects of ischaemia from necrosis to apoptosis to cell survival. It occurs in a wide variety of tissues, but it is most widely studied in the heart, and it occurs after a range of stimuli including hypoxia and the use of volatile anaesthetic agents. In this article, we look at the basic science, mechanisms, and potential uses of preconditioning.

Perioperative approach to precapillary pulmonary hypertension in non-cardiac non-obstetric surgery

Pulmonary hypertension (PH) confers a significant challenge in perioperative care. It is associated with substantial morbidity and mortality. A considerable amount of information about management of patients with PH has emerged over the past decade. However, there is still a paucity of information to guide perioperative evaluation and management of these patients. Yet, a satisfactory outcome is feasible by focusing on elaborate disease-adapted anaesthetic management of this complex disease with a multidisciplinary approach. The cornerstone of the peri-anaesthetic management of patients with PH is preservation of right ventricular (RV) function with attention on maintaining RV preload, contractility and limiting increase in RV afterload at each stage of the patient's perioperative care. Pre-anaesthetic evaluation, choice of anaesthetic agents, proper fluid management, appropriate ventilation, correction of hypoxia, hypercarbia, acid–base balance and pain control are paramount in this regard. Essentially, the perioperative management of PH patients is intricate and multifaceted. Unfortunately, a comprehensive evidence-based guideline is lacking to navigate us through this complex process. We conducted a literature review on patients with PH with a focus on the perioperative evaluation and suggest management algorithms for these patients during non-cardiac, non-obstetric surgery.

A systematic review of anaesthetic agents used in Drug Induced Sedation Endoscopy (DISE) and a description of a new DISE technique

ObjectivesDrug induced sleep endoscopy (DISE) is a standardly used investigation for surgical planning in obstructive sleep apnoea management once conservative treatments have proven inadequate. There are a variety of anaesthetic agents used to obtain sedation necessary for DISE. These agents may have different effect on the upper airway and other parameters important in the diagnosis of the site of collapse during sleep. We aimed to review the commonly agents and evaluate the significance of their impact on the the diagnosis.MethodsA search was conducted through PubMed looking for studies on commonly used anaesthetic agents and their effect on the upper airway and cardiopulmonary parameters. Results: Of the 109 studies yielded by the search, 19 were deemed relevant to the review and met all inclusion criteria. The agents reviewed were: propofol, dexmedetomidine, remifentanil, isoflurane, sevoflurane, midazolam and topical lidocaine. A meta-analysis was not conducted due to the limited number of relevant studies and the heterogeneity of outcomes measured. All agents examined gave some element of airway collapse and impact on cardiopulmonary measures. Most of these effects were shown to be dose-dependent. Of the agents considered dexmedetomidine and propofol gave the most consistently reliable and physiologically safe representations of upper airway collapse seen in OSA patients.ConclusionThere is limited information and no industry standard for the sedative regimen used for DISE. Of the agents reviewed those that caused least cardiopulmonary instability, respiratory depression and exaggerated upper airway collapse were deemed the most appropriate for DISE. The agent that best meet these criteria is dexmedetomidine followed by propofol.

The Safety Profile of General and Local Anaesthetic Agents: Data Collected during 20 Years of Spontaneous Reporting Activities in the Campania Region (Southern Italy)

Background: General and local anaesthetics are widely used during surgery. These drugs have peculiar safety profiles, being commonly associated with mild and reversible local adverse drug reactions (ADRs), but also with more severe and systemic ADRs, including respiratory and cardiovascular depression and anaphylaxis. Methods and Objectives: We carried out a descriptive analysis of Individual Case Safety Reports (ICSRs) sent to the Campania Regional Centre of Pharmacovigilance (Southern Italy) from 2001 to 2021 that reported general or local anaesthetics as suspected drugs, with the aim of describing their overall characteristics, focussing on the ADRs’ seriousness and distribution by System Organ Class (SOC) and Preferred Term (PT). Results: A total of 110 ICSRs documenting general or local anaesthetics were sent to the Italian pharmacovigilance database during 20 years of spontaneous reporting activities in the Campania region. ADRs mainly occurred in patients with a median age of 48 years and in a slightly higher percentage of men. ADRs were more commonly classified as not serious and had a favourable outcome. In terms of ADRs’ distribution by SOC and PT, both general and local anaesthetics were associated with general and cutaneous disorders, with common ADRs that included lack of efficacy, rash, and erythema. In addition, general anaesthetics were associated with the occurrence of respiratory ADRs, while local anaesthetics were associated with the occurrence of nervous ADRs. Conclusion: Even though a limited number of ICSRs documenting anaesthetics-induced ADRs were retrieved from the Italian spontaneous reporting database in the Campania region, we believe that the continuous monitoring of these drugs is highly recommended, especially among the frail population.

A survey of current practices, attitudes and demands of anaesthesiologists regarding the depth of anaesthesia monitoring in China

Background In this study, we aimed to analyse survey data to explore two different hypotheses; and for this purpose, we distributed an online survey to Chinese anaesthesiologists. The hypothetical questions in this survey include: (1) Chinese anaesthesiologists mainly use the depth of anaesthesia (DoA) monitors to prevent intraoperative awareness and (2) the accuracy of these monitors is the most crucial performance factor during the clinical daily practice of Chinese anaesthesiologists. Methods We collected and statistically analysed the response of a total of 12,750 anesthesiologists who were invited to participate in an anonymous online survey. The Chinese Society of Anaesthesiologists (CSA) trial group provided the email address of each anaesthesiologist, and the selection of respondents was random from the computerized system. Results The overall response rate was 32.0% (4037 respondents). Only 9.1% (95% confidence interval, 8.2-10.0%) of the respondents routinely used DoA monitors. Academic respondents (91.5, 90.3-92.7%) most frequently used DoA monitoring to prevent awareness, whereas nonacademic respondents (88.8, 87.4-90.2%) most frequently used DoA monitoring to guide the delivery of anaesthetic agents. In total, the number of respondents who did not use a DoA monitor and whose patients experienced awareness (61.7, 57.8-65.6%) was significantly greater than those who used one or several DoA monitors (51.5, 49.8-53.2%). Overall, the crucial performance factor during DoA monitoring was considered by 61.9% (60.4-63.4%) of the respondents to be accuracy. However, most respondents (95.7, 95.1-96.3%) demanded improvements in the accuracy of the monitors for DoA monitoring. In addition, broad application in patients of all ages (86.3, 85.2-87.4%), analgesia monitoring (80.4, 79.2-81.6%), and all types of anaesthetic agents (75.6, 74.3-76.9%) was reported. In total, 65.0% (63.6-66.5%) of the respondents believed that DoA monitors should be combined with EEG and vital sign monitoring, and 53.7% (52.1-55.2%) believed that advanced DoA monitors should include artificial intelligence. Conclusions Academic anaesthesiologists primarily use DoA monitoring to prevent awareness, whereas nonacademic anaesthesiologists use DoA monitoring to guide the delivery of anaesthetics. Anaesthesiologists demand high-accuracy DoA monitors incorporating EEG signals, multiple vital signs, and antinociceptive indicators. DoA monitors with artificial intelligence may represent a new direction for future research on DoA monitoring.

ĀKĀRAKARA AS DERMAL ANAESTHETIC

Nowadays, the role of local anaesthesia in the surgical field is highly appraisable. Local anaesthetics are the drugs that produce a loss of sensation over the localised areas without producing a loss of consciousness. Humans have been using various methods to block pain for thousands of years. Controlling pain during the śhastrakarma in śalyatantra has been always challenging. There has been the introduction of various methods of local anaesthetics since the origin of medical science, topical anaesthetics being one of them. Studies have been conducted to discover novel anaesthetic agents by various scholars. Herbal extracts do not stand far in the pathway of this search. Owing to these discoveries, 30% ethanolic extract gel of Ākārakara (Spilanthes calva DC.) is selected here as a topical anaesthetic to evaluate the efficacy in facilitating the management of warts by a painful procedure agnikarma. Keywords: Dermal anaesthetic, Ākārakara, Spilanthol

Complicated Paediatric Bronchial Foreign Body: A Novel Extraction Technique

A paediatric bronchoscopy procedure for foreign body inhalation is indeed a highly challenging procedure due to multiple risk factors such as lower physiological functional residual capacity and adverse pulmonary function effects by anaesthetic agents in addition to concurrent active lungs infection. Here we elucidate a novel technique of foreign body removal located at the distal airway in a paediatric patient and in a situation where a paediatric flexible bronchoscopy with built-in working channel is not available. A 1-year 7-months-old boy presented with acute respiratory distress syndrome following a one-week history of active respiratory infection. On examination, he was tachypnoeic with audible soft inspiratory stridor and intermittent barking cough despite being supplemented with 3 liters /minute oxygen mask. Chest x-ray showed right upper lobe collapse. He was referred to the otorhinolaryngology team after a suspicious history of foreign body aspiration obtained from his mother. Bedside flexible nasopharyngolaryngoscopy showed granulation tissue at the junction of laryngeal surface of epiglottis and anterior commissure. He underwent emergency direct laryngoscopy, tracheoscopy, bronchoscopy, excision of granulation tissue and removal of foreign body under general anaesthesia. Herein, some of complicated bronchoscopy demand critical thinking of alternative or modified techniques to achieve a successful and safe surgery. Bangladesh J Otorhinolaryngol 2021; 27(2): 177-183

Conduct of anaesthesia

This chapter describes the safe conduct of general anaesthesia. Topics covered include induction of anaesthesia; maintenance of anaesthesia; total intravenous anaesthesia; and volatile anaesthetic agents. The important methods of monitoring the patient are discussed in detail, including monitoring of neuromuscular blockade, depth of anaesthesia and cardiac output. The measurement and control of patient temperature is described. The common surgical positions are described, together with their safety concerns. The chapter finishes with a discussion of the prevention and treatment of postoperative nausea and vomiting.

Regional anaesthesia

This chapter discusses the techniques of regional anaesthesia and analgesia. It begins with an overview of regional anaesthesia and goes on to describe safe practice, and local anaesthetic agents. Techniques of locating nerves are then discussed, including ultrasound, and needle design is explored. Nerve blocks of the neck; upper limb; trunk; lower limb, and the neuraxis (spine) are described. Coagulation disorders, nerve injury and the management of local anaesthetic toxicity are discussed. The chapter concludes with a dermatome map and tables of recommended nerve blocks for particular operations.