The effect of dexmedetomidine on the perioperative hemodynamics and postoperative cognitive function of elderly patients with hypertension: Study protocol for a randomized controlled trial

Remimazolam vs Etomidate: Haemodynamic Effects in Hypertensive Elderly Patients Undergoing Non-Cardiac Surgery

Background

Remimazolam tosilate (RT) is a novel ultrashort-acting γ-aminobutyric acid subtype A (GABAA) agonist, with several advantages including rapid induction and recovery, stable haemodynamics, and mild respiratory inhibition. However, studies have not been conducted to explore the haemodynamic effects of RT in elderly hypertensive subjects undergoing non-cardiac surgery. Therefore, we sought to compare the effects of anaesthesia induction using different doses of RT and etomidate on the haemodynamics of this group of patients.

Methods

Patients were recruited into this single-center, prospective, randomized, double-blind trial from October 2022 to June 2023. A total of 150 hypertensive elderly undergoing non-cardiac surgery were randomly assigned into 0.2 mg/kg RT group (Group RL), 0.3 mg/kg RT group (Group RH) and 0.3 mg/kg etomidate group (Group E). The primary outcome of the study was haemodynamic changes (mean arterial pressure fluctuation value -∆MAP and heart rate fluctuation value -∆HR) observed during anaesthesia induction. Secondary outcomes included incidence of adverse cardiovascular events and adverse drug reactions (injection pain and myoclonus), cumulative doses of vasoactive drugs and vital signs at different time points.

Results

Patients in Group E and Group RL had significantly lower haemodynamic fluctuations (∆MAP), lower incidence of hypotension and cumulative dose of ephedrine than subjects in Group RH. Patients in groups RL and RH had significantly lower incidence of injection pain and myoclonus compared with patients in group E. The results showed no statistically significant differences in ∆HR, hypertension, bradycardia, tachycardia, and time to loss of eye-opening reflex and start of intubation, and vital signs at different time points among the three groups.

Conclusion

Use of low-dose RT (0.2 mg/kg) for induction of non-cardiac surgical anaesthesia in elderly hypertensive patients is more effective in maintaining haemodynamic stability and has fewer adverse effects compared with etomidate.

Dexmedetomidine-induced anesthesia in elderly patients undergoing hip replacement surgery

BACKGROUND

A femoral neck fracture is a common and frequently reported issue in orthopedics, with a greater rate of incidence among the elderly. Due to their advanced age and the presence of some primary diseases, both anesthesia and surgery are increasingly difficult in elderly patients with a femoral neck fractures. In fact, general anesthesia can easily induce complications such as cognitive dysfunction, which is not conducive to postoperative recovery.

AIM

To analyze the efficacy of dexmedetomidine in inducing anesthesia for elderly patients undergoing hip replacement surgery.

METHODS

A total of 98 elderly patients undergoing hip replacement in our hospital from June 2020 to June 2021 were randomly divided into control group (49 cases) and observation group (49 cases). The control group was given general anesthesia, and the observation group was combined with dexmedetomidine for anesthesia on the basis of the control group. Both groups were observed until the patients were discharged. The vital signs, serum inflammatory factors and renal function indexes of the two groups were compared before, during and 6 h after operation. The postoperative recovery and adverse events of the two groups were statistically analyzed.

RESULTS

Compared with the mean arterial pressure of the two groups, the intraoperative and postoperative 6 h was higher than that before the operation, the intraoperative was lower than the postoperative 6 h (P < 0.05); the blood oxygen saturation of the two groups was higher than that before operation and 6 h after operation, and the observation group was higher than the control group 6 h after operation (P < 0.05). The heart rate of the two groups was lower during and 6 h after operation than that before operation, and higher at 6 h after operation than that during operation (P < 0.05). The levels of serum C-reactive protein, tumor necrosis factor-α, interleukin-1β and kidney injury molecule-1 in the two groups were higher during operation and 6 h after operation than those before operation (P < 0.05). The level of serum urea nitrogen in the two groups was higher than that before operation, and that in the observation group was lower than that in the control group (P < 0.05). During hospitalization, the first time of getting out of bed, recovery time of grade II muscle strength, recovery time of grade III muscle strength and hospitalization time in the observation group were shorter than those in the control group (P < 0.05).

CONCLUSION

Dexmedetomidine can effectively improve the vital signs of elderly patients undergoing hip replacement surgery, reduce the body's inflammatory response and renal function damage, and promote postoperative recovery. Meanwhile, dexmedetomidine showcased a good safety profile and a good anesthetic outcome.

Study on the Effect of Dexmedetomidine on Postoperative Cognitive Dysfunction and Inflammation in Aged Rats

Objective

The aim of this study is to investigate the effect of dexmedetomidine on cognitive dysfunction and inflammatory cytokines in the hippocampus after surgery in aged rats.

Methods

A total of 30 healthy male Sprague Dawley rats were divided into control group, sham group, and dexmedetomidine group. A splenectomy rat model was established and dexmedetomidine was intraperitoneally injected before operation. The cognitive function of rats was examined by Morris Water-Maze Test, open field experiment, and passive avoidance memory test. And the expression levels of IL-6, IL-1β, and TNF-α in the hippocampus were examined by ELISA.

Results

The escape latency for 5 continuous days in dexmedetomidine group was significantly decreased comparing with control group (all P < 0.05). The number of times of swimming and the percentage of swimming time in dexmedetomidine group were significantly more than those in control group (all P < 0.05). What is more, rats in dexmedetomidine group had the decreased time of stay in the central square and the increased number of standing times in comparison with the control group, and the statistical differences were found (all P < 0.05). Compared with the control group, dexmedetomidine intraperitoneally injected before surgery could significantly inhibit the expression levels of IL-6, IL-1β, and TNF-α in the hippocampus, and there were statistical differences (all P < 0.05).

Conclusion

Dexmedetomidine could significantly relieve the postoperative cognitive dysfunction in aged rats. The mechanism may be associated with the decreased inflammatory cytokines in the hippocampus.

Dexmedetomidine attenuates hippocampal neuroinflammation in postoperative neurocognitive disorders by inhibiting microRNA-329-3p and activating the CREB1/IL1RA axis

RATIONALE

Due to its anti-inflammatory effect, dexmedetomidine (DEX) can confer neuroprotection in postoperative neurocognitive disorders (NCD). Here, the mechanism responsible for this effect of DEX is rarely ascertained.

OBJECTIVES

Our research was implemented to figure out mechanism governing the protection of DEX against hippocampal neuroinflammation in postoperative NCD.

METHODS

Exploratory laparotomy was applied for generating a postoperative NCD mouse model before bilateral hippocampal injection with microRNA (miR)-329-3p-agomir and intraperitoneal injection with DEX. Cognitive function of mice was evaluated by water maze test and fear conditioning test. Immunofluorescence was performed to assess microglial activation in hippocampus. After cell transfection and DEX treatment, mouse microglial cells (BV-2) were stimulated by lipopolysaccharide (LPS). IL-1β, IL-6, and TNF-α levels and the number of phagocytes were assessed by ELISA and flow cytometry. Dual-luciferase reporter assay was adopted to assess the relationship between miR-329-3p and CREB1.

RESULTS

miR-329-3p expression was reduced in the postoperative NCD mice after DEX treatment. DEX treatment or miR-329-3p downregulation caused attenuated cognitive dysfunction and microglia activation as well as reduced IL-1β, IL-6, and TNF-α levels in the hippocampus of the postoperative NCD mice. Mechanistically, miR-329-3p inversely targeted CREB1 that activated IL1RA in LPS-induced BV-2 cells. DEX treatment, miR-329-3p inhibition, or CREB1 or IL1RA upregulation curtailed the release of proinflammatory proteins and the number of phagocytes in LPS-induced BV-2 cells.

CONCLUSIONS

Collectively, our data provided the novel insight of the neuroprotective mechanism of DEX in postoperative NCD pertaining to the miR-329-3p/CREB1/IL1RA axis.

Effect of Preventive Analgesia with Nalbuphine and Dexmedetomidine in Endoscopic Sinus Surgery

Background

The study was to assess the efficacy and safety of nalbuphine combined with dexmedetomidine for preventive analgesia in endoscopic sinus surgery.

Methods

110 patients with deviation of the nasal septum were randomized into the nalbuphine group (group N), dexmedetomidine combined with nalbuphine group (group DN), and saline group (group C). Fifteen minutes before the induction of anesthesia, patients in group N were injected nalbuphine 0.2 mg/kg intravenously; patients in group DN received intravenous infusion of dexmedetomidine 0.5 μg/kg and injection of nalbuphine 0.2 mg/kg; patients in group C received 0.9% saline. Mean arterial pressure (MAP), heart rate (HR), numerical rating scale (NRS) scores, quality of recovery-40 (QoR-40) scores, the need for remedial analgesia, the consumption of remifentanil and propofol, and the incidence of adverse reactions were recorded.

Results

MAP, HR, and NRS scores of the DN group were significantly lower and the QoR-40 scores were higher than those of groups N and C (P < 0.001). The need for remedial analgesia, the consumption of remifentanil and propofol, and the incidence of nausea in the DN group were the lowest among the three groups (P < 0.001).

Conclusion

Preventive analgesia with nalbuphine and dexmedetomidine in endoscopic sinus surgery can not only maintain hemodynamic stability but also reduce intraoperative anesthetic dosage, postoperative pain, and improve the quality of postoperative recovery without affecting the revival and extubation time.

Effect of Dexmedetomidine on Perioperative Hemodynamics and Myocardial Protection in Thoracoscopic-Assisted Thoracic Surgery

BACKGROUND This study aimed to clarify the protective role of dexmedetomidine in thoracoscopic-assisted thoracic surgery (TATS), including control of the intraoperative heart rate, blood pressure, and myocardial injury markers. MATERIAL AND METHODS The patients who underwent TATS were divided into 2 equal groups: the dexmedetomidine group (dexmedetomidine pumped at 0.5 µg/kg for >10 min before the administration of anesthesia and at 0.5 µg/kg in the maintenance period) and the control group (pumped normal saline for >10 min before the administration of anesthesia). The data recorded for each patient were heart rate (preoperative, maximum intraoperative, and minimum intraoperative), systolic and diastolic blood pressure, intraoperative hemodynamic data, and intraoperative cardiovascular drugs administered. An enzyme-linked immunosorbent assay was performed to assess the postoperative levels of cardiac troponin I (cTnI), creatine kinase isoenzyme, myoglobin, and N-terminal pro-B-type natriuretic peptide (NT-proBNP). RESULTS There were no significant differences in the age, sex, body height, body weight, American Society of Anesthesiologists classification grade, resection mode, operation time, ejection fraction, basal heart rate, and systolic and diastolic blood pressure of the 2 groups. In the dexmedetomidine group, the patients' maximum intraoperative heart rate and diastolic pressure decreased, and the postoperative hospital stay period was shorter. The postoperative peripheral blood test for the dexmedetomidine group showed higher NT-proBNP levels and lower cTnI levels. CONCLUSIONS Preoperative administration of dexmedetomidine can benefit hemodynamic stability, protect the cardiovascular system in the intraoperative and postoperative periods, and shorten postoperative hospitalization.