Pharmacogenomics in Anesthesia

Comparison of the effects of 5 and 10 L/minute fresh gas flow on emergence from sevoflurane anesthesia: A randomized clinical trial

BACKGROUND

A high fresh gas flow of >5 L/minute is commonly used for emergence from inhalation anesthesia. In addition, a high fresh gas flow may have detrimental effects on climate change. However, no study has determined the optimal fresh gas flow for emergence from inhalation anesthesia. Therefore, we compared the effect of fresh gas flows of 5 L/minute and 10 L/minute on emergence time from sevoflurane anesthesia.

METHODS

Patients who were scheduled for transurethral resection of bladder tumor were randomly assigned to receive fresh gas flows of 5 L/minute (group 5) or 10 L/minute (group 10) during emergence. Emergence time was defined as the time from discontinuation of sevoflurane to tracheal extubation. The primary outcome was the emergence time, and the secondary outcomes were the time to self-movement and the time to eye-opening.

RESULTS

A total of 54 patients were included. In groups 5 and 10, emergence time (12.1 ± 2.9 minutes vs 11.1 ± 2.7 minutes, respectively; P = .232), time to self-movement (9.4 ± 3.8 minutes vs 8.5 ± 4.6 minutes, respectively; P = .435), and time to eye-opening (11.5 ± 3.1 minute vs 10.6 ± 3.0 minutes, respectively; P = .252) were not significantly different.

CONCLUSIONS

Emergence time, time to self-movement, and time to eye opening were not significantly different between fresh gas flow rates of 5 L/minute and 10 L/minute in transurethral resection of bladder tumor, thus suggesting that fresh gas flow of 5 L/minute is sufficient for emergence from sevoflurane anesthesia.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT05376631).

Comparison of the Efficacy of Opioid-Free Anesthesia With Conventional Opioid-Based Anesthesia for Nasal Surgeries - A Prospective Randomized Parallel Arm Triple-Blinded Study

Introduction In the setting of nasal surgeries, the use of opioid-free anesthesia involving the use of dexmedetomidine, and lignocaine is being investigated as a potential alternative to opioids. This combination of drugs provides sympatholysis, pain relief, and sedative properties, thereby aiming at reducing the negative effects commonly associated with opioid usage. The objective of this study is to evaluate and compare the effectiveness of opioid-free anesthesia using dexmedetomidine and lignocaine versus conventional opioid anesthesia with fentanyl for nasal surgeries. The comparison will be based on the primary outcome of postoperative visual analog scale (VAS) scores. Secondary outcomes assessed were the amount of rescue analgesic consumption, intraoperative sevoflurane usage, intraoperative blood loss, hemodynamic stability, postoperative nausea and vomiting (PONV) scores, and postoperative Ramsay Sedation Scores. Methods A triple-blind, prospective, randomized, parallel arm study in which 48 patients planned for elective nasal surgery were allocated randomly to one of two groups. In the study, the population labeled as Group D, comprising 24 participants, received dexmedetomidine at a dosage of 1 mcg.kg^-1 via intravenous infusion lasting for a duration of 10 minutes prior to the induction of anesthesia. This was followed by a continuous infusion of 0.6 mcg.kg^-1 h^-1 throughout the intraoperative period, and intravenous Lignocaine 1.5 mg.kg^-1 was administered three minutes prior to induction, subsequently an intraoperative infusion of 1.5 mg.kg^-1 h^-1. In Group F, consisting of 24 participants, intravenous fentanyl of 2 mcg.kg^-1 was administered three minutes before the induction. This was subsequently followed by a fentanyl infusion of 0.5 mcg.kg^-1h^-1 in the intraoperative period. Results The study findings indicate that Group D had considerably lower postoperative VAS scores from 30 minutes to two hours compared to Group F (p<0.05). The utilization of sevoflurane during the intraoperative period was comparatively reduced in Group D in order to achieve the desired bispectral index (BIS) range of 40-60 (p<0.01). Mean intraoperative blood loss was also lower in Group D (85 ml) compared to Group F (115 ml )(p<0.01). Additionally, Group D had significantly lower rescue analgesic consumption and lower incidence of PONV up to 60 minutes compared to Group F (P-value <0.01). A statistically significant difference was observed between Group D and Group F in terms of lower mean values of both mean arterial pressure (MAP) and heart rate in Group D (p<0.01). The results indicate that the postoperative sedation scores within the first two hours were significantly greater in Group D compared to Group F (p<0.01). Conclusion The usage of opioid-free anesthesia has been found to be superior to a traditional opioid-based approach in various aspects, including the provision of sufficient pain relief after surgery, maintenance of stable hemodynamics during the operation, and reduction in occurrences of postoperative nausea and vomiting.

Pharmacogenomic profile of actionable molecular variants related to drugs commonly used in anesthesia: WES analysis reveals new mutations

Background: Genetic interindividual variability is associated with adverse drug reactions (ADRs) and affects the response to common drugs used in anesthesia. Despite their importance, these variants remain largely underexplored in Latin-American countries. This study describes rare and common variants found in genes related to metabolism of analgesic and anaesthetic drug in the Colombian population. Methods: We conducted a study that included 625 Colombian healthy individuals. We generated a subset of 14 genes implicated in metabolic pathways of common medications used in anesthesia and assessed them by whole-exome sequencing (WES). Variants were filtered using two pipelines: A) novel or rare (minor allele frequency-MAF <1%) variants including missense, loss-of-function (LoF, e.g., frameshift, nonsense), and splice site variants with potential deleterious effect and B) clinically validated variants described in the PharmGKB (categories 1, 2 and 3) and/or ClinVar databases. For rare and novel missense variants, we applied an optimized prediction framework (OPF) to assess the functional impact of pharmacogenetic variants. Allelic, genotypic frequencies and Hardy-Weinberg equilibrium were calculated. We compare our allelic frequencies with these from populations described in the gnomAD database. Results: Our study identified 148 molecular variants potentially related to variability in the therapeutic response to 14 drugs commonly used in anesthesiology. 83.1% of them correspond to rare and novel missense variants classified as pathogenic according to the pharmacogenetic optimized prediction framework, 5.4% were loss-of-function (LoF), 2.7% led to potential splicing alterations and 8.8% were assigned as actionable or informative pharmacogenetic variants. Novel variants were confirmed by Sanger sequencing. Allelic frequency comparison showed that the Colombian population has a unique pharmacogenomic profile for anesthesia drugs with some allele frequencies different from other populations. Conclusion: Our results demonstrated high allelic heterogeneity among the analyzed sampled, enriched by rare (91.2%) variants in pharmacogenes related to common drugs used in anesthesia. The clinical implications of these results highlight the importance of implementation of next-generation sequencing data into pharmacogenomic approaches and personalized medicine.

Cardioprotective Effect of Anesthetics: Translating Science to Practice

Cardiovascular diseases are the number one cause of mortality in the world, particularly among the aging population. Major adverse cardiac events are also a major contributor to perioperative complications, affecting 2.6% of noncardiac surgeries and up to 18% of cardiac surgeries. Cardioprotective effects of volatile anesthetics and certain intravenous anesthetics have been well-documented in preclinical studies; however, their clinical application has yielded conflicting results in terms of their efficacy. Therefore, better understanding of the underlying mechanisms and developing effective ways to translate these insights into clinical practice remain significant challenges and unmet needs in the area. Several recent reviews have focused on mechanistic dissection of anesthetic-mediated cardioprotection. The present review focuses on recent clinical trials investigating the cardioprotective effects of anesthetics in the past five years. In addition to highlighting the main outcomes of these trials, the authors provide their perspectives about the current gap in the field and potential directions for future investigations.

Precision Medicine in Acute Brain Injury: A Narrative Review

Over the past few years, the concept of personalized medicine has percolated into the management of different neurological conditions. Improving outcomes after acute brain injury (ABI) continues to be a major challenge. Unrecognized individual multiomic variations in addition to multiple interacting processes may explain why we fail to observe comprehensive improvements in ABI outcomes even when applied treatments appear to be beneficial logically. The provision of clinical care based on a multiomic approach may revolutionize the management of traumatic brain injury, delayed cerebral ischemia after subarachnoid hemorrhage, acute ischemic stroke, and several other neurological diseases. The challenge is to incorporate all the information obtained from genomic studies, other omic data, and individual variability into a practical tool that can be used to assist clinical decision-making. The effective execution of such strategies, which is still far away, requires the development of protocols on the basis of these complex interactions and strict adherence to management protocols. In this review, we will discuss various omics and physiological targets to guide individualized patient management after ABI.

Perioperative Heart-Brain Axis Protection in Obese Surgical Patients: The Nutrigenomic Approach

The number of obese patients undergoing cardiac and noncardiac surgery is rapidly increasing because they are more prone to concomitant diseases, such as diabetes, thrombosis, sleep-disordered breathing, cardiovascular and cerebrovascular disorders. Even if guidelines are already available to manage anesthesia and surgery of obese patients, the assessment of the perioperative morbidity and mortality from heart and brain disorders in morbidly obese surgical patients will be challenging in the next years. The present review will recapitulate the new mechanisms underlying the Heart-brain Axis (HBA) vulnerability during the perioperative period in healthy and morbidly obese patients. Finally, we will describe the nutrigenomics approach, an emerging noninvasive dietary tool, to maintain a healthy body weight and to minimize the HBA propensity to injury in obese individuals undergoing all types of surgery by personalized intake of plant compounds that may regulate the switch from health to disease in an epigenetic manner. Our review provides current insights into the mechanisms underlying HBA response in obese surgical patients and how they are modulated by epigenetically active food constituents.

Challenges in anesthesia personalization: resolving the pharmacogenomic puzzle

Clinicians are witnessing differences in the doses required for induction and maintenance of anesthesia, as well as prolonged recovery in some patients. Predictable factors like patient characteristics, factors related to the procedure, pharmacological characteristics of anesthetics and adjunctive drugs, might explain some of the observed differences. However, the role of various polymorphisms of genes encoding for drugs’ molecular targets, transporters and metabolic enzymes can have a significant impact on anesthesia outcome, too. In the present paper, we critically discuss pharmacological characteristics of the most common drugs used in anesthesia, with a focus on the possible genetic background of unpredictable diversities in anesthesia outcomes.

Potential role of pharmacogenomics testing in the setting of enhanced recovery pathways after surgery

In 2001, a group of European academic surgeons created the Enhanced Recovery After Surgery (ERAS) study group and established the first official ERAS protocol. One of the most significant challenges during ERAS implementation is variability of drugs used throughout the perioperative period. Pharmacogenomic testing (blood or saliva) results (obtained within approximately 48 hrs) provide guidelines on how to prescribe the optimal drug with the optimal dosage to each patient based on an individual's unique genetic profile. Pharmacogenomic testing of various methods of multimodal analgesia is an essential element of ERAS protocols spanning the entire perioperative period to ultimately optimize postoperative pain control. The key goal for anesthetic management in ERAS protocols is to facilitate rapid emergence by using the shortest acting agents available, thus accelerating recovery and reducing length of stay, hospital expenses, and postoperative complications. Postoperative nausea and vomiting (PONV) is an additional challenge that should be overcome to ensure an enhanced recovery and shorter length of stay with the use of antiemetics. Postoperative ileus (POI) can result in longer hospital stay with increasing susceptibility to associated morbidities along with an increase in associated hospitalization costs. Genetics-guided pharmacotherapy and its impact on clinical outcomes should be thoroughly studied for better understanding and managing drug administration in the settings of ERAS.

What we can learn from Big Data about factors influencing perioperative outcome

PURPOSE OF REVIEW

This narrative review will discuss what value Big Data has to offer anesthesiology and aims to highlight recently published articles of large databases exploring factors influencing perioperative outcome. Additionally, the future perspectives of Big Data and its major pitfalls will be discussed.

RECENT FINDINGS

The potential of Big Data has given an incentive to create nationwide and anesthesia-initiated registries like the MPOG and NACOR. These large databases have contributed in elucidating some of the rare perioperative complications, such as declined cognition after exposure to general anesthesia and epidural hematomas in parturients. Additionally, they are useful in finding patterns such as similar outcome in subtypes of beta-blockers and lower incidence of pneumonia in preoperative influenza vaccinations in the elderly.

SUMMARY

Big Data is becoming increasingly popular with the collaborative collection of registries offering anesthesia a way to explore rare perioperative complications and outcome to encourage further hypotheses testing. Although Big Data has its flaws in security, lack of expertise and methodological concerns, the future potential of analytics combined with genomics, machine learning and real-time decision support looks promising.

Clinical Pharmacogenetics Implementation Consortium (CPIC) Guideline for the Use of Potent Volatile Anesthetic Agents and Succinylcholine in the Context of RYR1 or CACNA1S Genotypes

The identification in a patient of 1 of the 50 variants in the RYR1 or CACNA1S genes reviewed here should lead to a presumption of malignant hyperthermia susceptibility (MHS). MHS can lead to life-threatening reactions to potent volatile anesthetic agents or succinylcholine. We summarize evidence from the literature supporting this association and provide therapeutic recommendations for the use of these agents in patients with these RYR1 or CACNA1S variants (updates at https://cpicpgx.org/guidelines and www.pharmgkb.org).

Genomics Testing and Personalized Medicine in the Preoperative Setting

Pharmacogenomics (PGx) is the study of how individuals' personal genotypes may affect their responses to various pharmacologic agents. The application of PGx principles in perioperative medicine is fairly novel. Challenges in executing PGx programs into health care systems include physician buy-in and integration into usual clinical workflow, including the electronic health record. This article discusses the current evidence highlighting the potential of PGx with various drug categories (including opioids, nonopioid analgesics, sedatives, β-blockers, antiemetics, and anticoagulants) used in the perioperative process and the challenges of integrating PGx into a health care system and relevant workflows.