Clinical effect of ultrasound-guided nerve block and dexmedetomidine anesthesia on lower extremity operative fracture reduction

Effects of dexmedetomidine on early postoperative cognitive function and postoperative inflammatory response: a systematic review and network meta-analysis

Background

Dexmedetomidine (DEX) has demonstrated potential as an effective agent for enhancing early postoperative cognitive function. However, there is ongoing debate regarding its optimal dosage and impact on early postoperative inflammatory response. This study aimed to assess and prioritize the effects of varying doses of DEX on early postoperative cognitive function and inflammatory response, in order to identify the most effective intervention dosage.

Methods

Randomised controlled trials (RCTs) and retrospective cohort studies (RCS) from PubMed, Embase, and Cochrane Library up to January 28, 2024, were included. The Mini-Mental State Examination (MMSE) was utilized to assess the impact of varying doses of DEX on cognitive function during the early postoperative period as the primary outcome, peripheral blood levels of IL-6 and TNF-α were considered as secondary outcomes. Meta-analysis and Bayesian Network Meta-Analysis (NMA) were conducted using R. Funnel plots were generated using Stata 15.0.

Results

A total of 29 studies involving 2,807 patients and 25 different doses of DEX were included. DEX was given at a loading dose of 0.3-1.0 μg/kg followed by a maintenance dose of 0.1-0.5 μg/kg/h, or at a uniform intraoperative dose of 0.4-0.7 μg/kg/h. Network meta-analysis revealed most doses of DEX were significantly more effective than normal saline (NS) in improving postoperative MMSE scores (on days 1, 3, and 7) and lowering IL-6 and TNF-α levels. Probability results showed that a 1 μg/kg loading dose followed by a 0.6 μg/kg/h maintenance dose was the best dosing regimen for improving MMSE scores on postoperative days 1 (97.3%), 3 (100%), and 7 (99.9%), as well as for reducing postoperative blood IL-6 levels (1.3%). On the other hand, 0.3 μg/kg followed by 0.2 μg/kg/h was the optimal dosing regimen for reducing postoperative blood TNF-α levels (6.6%).

Conclusion

Compared with NS, intraoperative intravenous DEX improved early postoperative cognitive function and postoperative inflammatory response in patients undergoing elective surgery. In particular, a 1 μg/kg loading dose and a 0.6 μg/kg/h maintenance dose resulted in the best improvement in postoperative MMSE scores and blood IL-6 levels, while a 0.3 μg/kg loading dose followed by a 0.2 μg/kg/h maintenance dose is the optimal regimen for lowering postoperative blood TNF-α levels.Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=433932, identifier CRD42023433932.

Prevention of Dexmedetomidine on Postoperative Delirium and Early Postoperative Cognitive Dysfunction in Elderly Patients Undergoing Thoracoscopic Lobectomy

Objective

To investigate the effect of dexmedetomidine on postoperative cognitive function and delirium in elderly patients undergoing thoracoscopic lobectomy.

Methods

109 elderly patients (age is more than 65 years) who underwent thoracoscopic lobectomy in our hospital from June 2020 to Feb 2022 were randomly divided into the dexmedetomidine (DEX) group (n = 54) and the control group (n = 55). The patients in the experimental group were given dexmedetomidine by intravenous pump, intravenous pump 0.5 μg/kg within 10 minutes, and maintained the speed of 0.5 μg/(kg. h) to 30 min before the operation was ended. The control group was given the same amount of normal saline. Delirium assessment-severity (CAM-S) assessment and Mini-Cog were used to assess the severity levels of POD and POCD 24 h before, 6 hours after, one day after the operation, three days after the operation, and 1 week after the operation. Serum TNF-αα and NSE levels were assessed by using enzyme-linked immunosorbent assay. NRS pain marks were assessed in the DEX group at postanesthesia care unit (PACU) and 24 postoperation. Surgical pierhysmographic index (SPI) evaluation was performed at five time points.

Results

The Mini-Cog scores in the DEX group were markedly enhanced compared with those in the saline group 6 and 24 hours after the operation. The SPI values in the DEX group were markedly reduced within 2 min after intubation and at surgical sutures. Moreover, the CAM scores in the DEX group were markedly reduced 24 hours after the operation. Tumor necrosis factor-α (TNF-α) and neuron-specific enolase (NSE) levels were significantly decreased in the DEX group at T1∼T3.

Conclusion

The use of dexmedetomidine in the thoracoscopic lobectomy in elderly patients could reduce the occurrence and severity of postoperative cognitive dysfunction and delirium.

Impacts of Ultrasound-Guided Nerve Block Combined with General Anesthesia with Laryngeal Mask on the Patients with Lower Extremity Fractures

Objective

Surgical reduction is the leading approach to patients with lower extremity fractures. The options of anesthetic drugs during surgery are of great significance to postoperative recovery of patients. There is no consensus on the optimum anesthesia method for patients undergoing lower extremity fracture surgery. Our study is aimed at investigating the impacts of nerve block combined with general anesthesia on perioperative outcomes of the patients.

Methods

In this retrospective study, 48 patients experienced general anesthesia only, and 42 patients received never block combined with general anesthesia. The perioperative hemodynamics was recorded, including mean arterial pressure (MAP), oxygen saturation of blood (SpO2), and heart rate (HR). Visual analogue scale (VAS) and Montreal Cognitive Assessment (MoCA) were carried out to evaluate postoperative pain and cognitive status. Furthermore, adverse reactions and recovery condition were observed between the patients receiving different anesthesia methods.

Results

At 15 minutes and 30 minutes after anesthesia, as well as 5 minutes after surgery, significant lower MAP was observed in the patients treated with general anesthesia (83.04 ± 8.661, 79.17 ± 9.427, 86.58 ± 8.913) compared to those receiving never block combined with general anesthesia (90.43 ± 4.618, 88.74 ± 6.224, 92.21 ± 4.015) (P < 0.05), and compared with general anesthesia group (68.5 ± 7.05, 69.63 ± 7.956, 72.75 ± 8.446), the combined anesthesia group (73.52 ± 9.451, 74.17 ± 10.13, 77.62 ± 9.768) showed obvious higher HR (P < 0.05). No significant difference in SpO2 was found between the two groups at multiple time points (P > 0.05). As for the score of VAS and MoCA, remarkably lower VAS and higher MoCA at 6 h, 12 h and 24 h after surgery were presented in the combined anesthesia group compared to general anesthesia group (P < 0.05). At 24 h after surgery, the two groups showed normal cognitive function (26.33 ± 0.7244 vs. 28.55 ± 0.7392). Incidence of nausea and vomiting in the combined anesthesia group was lower than that of the general anesthesia group (P < 0.05). The time to out-of-bed activity and hospital stay were shorter in the combined anesthesia group compared with general anesthesia (P < 0.05).

Conclusion

The application of never block combined with general anesthesia contributed to the stability of hemodynamics, alleviation of postoperative pain and cognitive impairment, along with decrease in adverse reactions and hospital stay in the patients with lower extremity fractures.