Intraoperative Vitamin C Reduces the Dosage of Propofol in Patients Undergoing Total Knee Replacement

Propofol alleviates spinal cord ischemia-reperfusion injury by preserving PI3K/AKT/GIT1 axis

Spinal cord ischemia-reperfusion injury (SCIRI) is a major contributor to neurological damage and mortality associated with spinal cord dysfunction. This study aims to explore the possible mechanism of Propofol and G-protein-coupled receptor-interacting protein 1 (GIT1) in regulating SCIRI in rat models. SCIRI rat models were established and injected with Propofol, over expression of GIT1 (OE-GIT1), or PI3K inhibitor (LY294002). The neurological function was assessed using Tarlov scoring system, and Hematoxylin & Eosin (H&E) staining was applied to observe morphology changes in spinal cord tissues. Cell apoptosis, blood-spinal cord barriers (BSCB) permeability, and inflammatory cytokines were determined by TdT-mediated dUTP Nick-End Labeling (TUNEL) staining, evans blue (EB) staining, and enzyme-linked immuno sorbent assay (ELISA), respectively. Reverse transcription-quantitative polymerase chain reaction and western blot were used to detect the expression levels of GIT1, endothelial nitric oxide synthase (eNOS), PI3K/AKT signal pathway and apoptosis-related proteins. SCIRI rats had decreased expressions of GIT1 and PI3K/AKT-related proteins, whose expressions can be elevated in response to Propofol treatment. LY294002 can also decrease GIT1 expression levels in SCIRI rats. Propofol can attenuate neurological dysfunction induced by SCIRI, decrease spinal cord tissue injury and BSCB permeability in addition to suppressing cell apoptosis and inflammatory cytokines, whereas further treatment by LY294002 can partially reverse the protective effect of Propofol on SCIRI. Propofol can activate PI3K/AKT signal pathway to increase GIT1 expression level, thus attenuating SCIRI in rat models.

Anti-Inflammatory Effect of Vitamin C during the Postoperative Period in Patients Subjected to Total Knee Arthroplasty: A Randomized Controlled Trial

Vitamin C, a potent reducing and antioxidant agent, plays an important role in the body, aiding in the growth of cartilage and bones. It is also involved in mechanisms that help reduce inflammation and its effects on the body. In addition, vitamin C decreases pro-inflammatory cytokines, such as IL-6, which produce acute-phase proteins such as CRP and influence inflammatory markers such as ESR. We carried out a study with 110 patients who underwent total knee replacement surgery. We divided the patients into two groups, in which the intervention group received 15 g of parenteral vitamin C during the immediate postoperative period while the control group did not. Patients who received 15 g of vitamin C after total knee replacement surgery had decreased inflammatory markers, specifically CRP and ESR. Overall, administering vitamin C in the post-surgical period results in improved management of inflammation, as evidenced by a decrease in CRP and ESR values. This leads to faster recovery and better healing outcomes for patients undergoing total knee replacement surgery. Furthermore, the beneficial effects of vitamin C in reducing proinflammatory cytokines, reducing the need for opioid analgesics, and its mild adverse effects make it a promising adjuvant in managing postoperative recovery.

Effect of Vitamin C Infusion on Cerebral Oximetry During General Anesthesia for Carotid Endarterectomy in Diabetic Patients

Background

There is conflicting information about the effect of vitamin C on brain oxygenation during anesthesia.

Objectives

The current study was designed and performed to assess the effect of vitamin C infusion and brain oxygenation with cerebral oximetry on improving brain perfusion during general anesthesia in vascular surgery of diabetic patients.

Methods

This randomized clinical trial was performed on patients candidates for endarterectomy under general anesthesia and referred to Taleghani Hospital in Tehran, Iran, during 2019 - 2020. Considering inclusion criteria, the patients were divided into placebo and intervention groups. The patients in the placebo group received 500 mL of isotonic saline. In the intervention group, the patients received 1 g of vitamin C diluted in 500 mL of isotonic saline by infusion half an hour before anesthesia induction. Patients' oxygen levels were continuously measured by a cerebral oximetry sensor. The patients were put in a supine position for 10 minutes before and after anesthesia. At the end of the surgery, the indicators considered in the study were evaluated.

Results

No considerable difference was observed between systolic and diastolic blood pressure, heart rate, mean arterial pressure, partial pressure of carbon dioxide, oxygen saturation, regional oxygen saturation, supercritical carbon dioxide, and end-tidal carbon dioxide in total and between the two groups in the three stages before and after anesthesia induction and at the end of surgery (P > 0.05). Additionally, there was no significant difference between blood sugar (BS) levels in the study groups (P > 0.05) but in BS levels at three stages before and after anesthesia induction and at the end of the surgery, with a significant difference (P < 0.05).

Conclusions

The amount of perfusion in the two groups and, therefore, in total at the three stages before and after anesthesia induction and at the end of surgery is not different.

ED50 and ED95 of propofol combined with different doses of esketamine for children undergoing upper gastrointestinal endoscopy: A prospective dose-finding study using up-and-down sequential allocation method

WHAT IS KNOWN AND OBJECTIVE

Propofol and esketamine are routine anaesthetics used in sedation or general anaesthesia for paediatric procedures. Coadministration could reduce the dose of either propofol or esketamine required and lower the incidence of drug-related adverse events. We designed a four-arm randomized controlled trial in children undergoing diagnostic upper gastrointestinal endoscopy to investigate the dose of propofol with different doses of esketamine inducing appropriate depth of anaesthesia in 50% patients (median effective dose, ED₅₀ ).

METHODS

After getting the approval of the research ethics committee and informed consent, 92 paediatric patients planning for upper gastrointestinal endoscopy were divided into four groups randomly: esketamine 0, 0.25, 0.5 and 1 mg/kg groups (n = 23/group). Propofol doses followed the Dixon and Massey up-and-down method with different starting and interval doses between groups. During the first attempt of endoscope insertion, if patients' reactions prevented the insertion, it would be considered as a failure. The awakening time, total propofol doses, as well as the perioperative and post-procedure adverse events were evaluated and recorded for each patient.

RESULTS AND DISCUSSION

The ED₅₀ (median, 95% confidence interval) of propofol was significantly greater in esketamine 0 and 0.25 mg/kg groups in comparison with the esketamine 0.5 and 1 mg/kg groups (4.1 [3.3-4.9]; 3.1 [2.5-3.8] mg/kg vs. 1.8 [1.1-2.4]; 0.8 [0.2-1.3] mg/kg, respectively, p < .05). The total doses of propofol in esketamine 0.5 and 1 mg/kg groups were statistically lower than these in esketamine 0 and 0.25 mg/kg group (p < .01). The mean blood pressure was lower in the esketamine 0 mg/kg group than that in 1 mg/kg group after administration and during the procedure (p < .01). The esketamine 1 mg/kg group showed a higher incidence of vomiting and visual disturbances than the other three groups (p < .001).

WHAT IS NEW AND CONCLUSION

In children who accomplished diagnostic paediatric upper gastrointestinal endoscopy under deep sedation/anaesthesia, the total dosage of propofol needed was reduced significantly in esketamine 0.5 and 1 mg/kg groups with a corresponding reduce in propofol-related hemodynamic changes. However, a higher incidence of esketamine-related adverse effects was found in esketamine 1 mg/kg group.