Pharmacogenomics of inhalational anesthetic agents

Comparison of the Sevoflurane versus Desflurane Anaesthesia on the Recovery of Airway Reflexes and Cognitive Function: An Original Research

Background and Objectives

Sevoflurane and desflurane virtually equally dissolve in blood gases, yet current research suggests that desflurane helps in a quick return of airway reflex than sevoflurane however the return of cognitive activity fluctuates greatly. In order to compare the lengths of time required to recover after sevoflurane and desflurane anesthesia, the current research was conducted.

Materials and Methods

Current study was randomized that included 100 subjects who were posted for cholecystectomy (elective). Only adult and non-obese subjects were included in the study. The intended anesthetic agents sevoflurane and desflurane were utilized in the study and all the protocols were followed for the surgery. After the end of the surgery, tests for regaining cognitive function and airway reflexes were carried out, and different time intervals were recorded. The values were recorded and compared for the variances while considering the P < 0.05 as significant.

Results

The mean T1 was 8.19 ± 3.28 min for sevoflurane and was 5.82 ± 4.02 min. There was no significant variance between the two agents for the T1, 2 (P = 0.013 and 0.110 respectively). After the inhalation anesthetics ceased at T1, desflurane patients responded to verbal commands more quickly than sevoflurane patients (5.824.02 vs. 8.193.28 min). The SOMCT and swallowing test were similarly completed more quickly by desflurane-treated patients than by sevoflurane-treated patients (T3VST4) (13.693.37 vs. 10.024.86 min, P = 0.008 and (14.094.30 vs. 9.824.50 min, P 0.001, respectively). For the T3, 4-time intervals, there was a significant difference between the sevoflurane and desflurane groups.

Conclusion

Desflurane causes patients to recover more quickly from laparoscopic cholecystectomy under controlled circumstances than sevoflurane does.

The effect of desflurane, isoflurane and sevoflurane on the hemoglobin oxygen dissociation curve in human blood samples

Desflurane, isoflurane and sevoflurane, three halogenated ethers, are commonly used inhaled anesthetics, both in the operating room and in the intensive care unit (ICU). The potency and dosage of these drugs is expressed by the MAC value (minimum alveolar concentration). Their interaction with hemoglobin and its affinity for oxygen, best described by the oxygen dissociation curve (ODC), has already been investigated, with conflicting results. Altered by many factors, the ODC can be shifted to the left or to the right, therefore increasing or decreasing hemoglobin oxygen (Hb-O₂) affinity. In venous blood samples of 22 healthy participants (11 female, 11 male) ODC were measured with a high-throughput method in vitro. Blood samples were either exposed to control or to three different concentrations of desflurane, isoflurane or sevoflurane prior to and during measurements (low, medium and high corresponding to MAC 0.5, MAC 1.0 and MAC 2.0). With increasing concentrations from control to medium, desflurane and isoflurane significantly decreased Hb-O₂ affinity by shifting the ODC to the right (p = 0.016 and p < 0.001) but sevoflurane showed no effects. When further increasing concentrations from medium to high, all three inhaled anesthetics shifted the ODC back to the left (p < 0.001). Comparing only controls to high concentrations, a significant increase in Hb-O₂ affinity for desflurane (p = 0.005) and sevoflurane (p < 0.001) was detected. Our study shows a varying effect at different doses of inhaled anesthetics on Hb-O₂ affinity. While the underlying mechanisms remain unclear, these results show an effect which needs to be further investigated to determine if patients undergoing anesthesia may potentially benefit or get disadvantage from this slightly increased (e.g. impaired pulmonary oxygen uptake), or decreased Hb-O₂ affinity (e.g. arterial vascular disease).

Trial registration: This study is registered with clinicaltrials.gov (NCT04612270).

Effects of Volatile Anaesthetics and Iron Dextran on Chronic Inflammation and Antioxidant Defense System in Rats

Iron, as an essential microelement, is involved in cell proliferation, metabolism, and differentiation. It also modulates the fate and function of macrophages in hematopoiesis and macrophage-mediated inflammatory responses. On the other hand, anesthetics can affect the inflammatory process by modulating the response to stress or the functions of immune cells. The aim of this paper is to understand how excessive iron intake alters physiological, functional characteristics of peripheral tissues and whether different anesthetics can alter cell metabolism regarding oxidative stress (OS) and inflammation through regulation of macrophage polarization. Y59 rats were injected intraperitoneally with iron dextran solution at a dose of 50 mg/kg or were exposed to inhaled anesthetics sevoflurane and isoflurane and their combination for 28 days every other day. The results show that the use of anesthetics reduces the rat’s organ weight and increases OS in peripheral tissues, leading to M1 macrophage polarization. Excessive iron intake leads to increased OS, inflammation, and an increased ratio of IL-12/IL-10 cytokines to the M1 macrophage phenotype. Iron, in combination with sevoflurane, has a protective effect in tissues showing the M2 phenotype of macrophages. The combination of iron dextran and isoflurane in rats leads to an increase in the erythropoiesis process made possible through the induction of hypoxia.

Comparative study of recovery of airway reflexes and cognitive function following sevoflurane versus desflurane anaesthesia

Background and Aims

Sevoflurane and desflurane have almost similar blood-gas solubility but recent studies suggest that desflurane compared to sevoflurane leads to faster recovery of airway reflexes, but the recovery of cognitive function varies significantly. We conducted this study to compare the times of recovery from anaesthesia following desflurane versus sevoflurane anaesthesia.

Methods

This randomised double-blinded study was conducted on 60 patients of American Society of Anesthesiologists (ASA) classification I-II, age between 18 and 60 years with body mass index (BMI) ≤30 kg/m² who underwent elective cholecystectomy. A standard general anaesthesia protocol was followed with either sevoflurane (group A = 30 patients) or desflurane (group B = 30 patients) along with bispectral index and neuromuscular monitoring. Following extubation, tests for recovery of airway reflexes and cognitive function were conducted and various time intervals were noted. Statistical analysis was carried out using Statistical Package for Social Sciences (SPSS) standard software version 17.

Results

The mean time from first verbal response to first passing the swallowing test was comparable in both the groups (5.50 ± 3.45 vs. 4.10 ± 3.42 min, P value = 0.120). Patients receiving desflurane showed faster response to verbal commands (5.93 ± 4.13 vs. 8.20 ± 3.39 min, P value = 0.024), passed the swallowing test earlier (10.03 ± 4.97 vs. 13.70 ± 3.48 min, P value = 0.009) and Short orientation memory concentration test (SOMCT) earlier (9.83 ± 4.51 vs. 14.10 ± 4.31 min, P value ≤0.001) compared to sevoflurane.

Conclusion

In patients undergoing laparoscopic cholecystectomy under controlled conditions, earlier recovery is seen with desflurane compared to sevoflurane.

Personalized pediatric anesthesia and pain management: problem-based review

Pharmacogenetics, the genetic influence on the interpersonal variability in drug response, has enabled tailored pharmacotherapy and emerging 'personalized medicine.' Although oncology spearheaded the clinical implementation of personalized medicine, other specialties are rapidly catching up. In anesthesia, classical examples of genetically mediated idiosyncratic reactions have been long known (e.g., malignant hyperthermia and prolonged apnea after succinylcholine). The last two decades have witnessed an expanding body of pharmacogenetic evidence in anesthesia. This review highlights some of the prominent pharmacogenetic associations studied in anesthesia and pain management, with special focus on pediatric anesthesia.

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.