Dexmedetomidine improves neurodevelopment and cognitive impairment in infants with congenital heart disease

The role of anesthesia in peri‑operative neurocognitive disorders: Molecular mechanisms and preventive strategies

Peri-operative neurocognitive disorders (PNDs) include postoperative delirium (POD) and postoperative cognitive dysfunction (POCD). Children and the elderly are the two populations most vulnerable to the development of POD and POCD, which results in both high morbidity and mortality. There are many factors, including neuroinflammation and oxidative stress, that are associated with POD and POCD. General anesthesia is a major risk factor of PNDs. However, the molecular mechanisms of PNDs are poorly understood. Dexmedetomidine (DEX) is a useful sedative agent with analgesic properties, which significantly improves POCD in elderly patients. In this review, the current understanding of anesthesia in PNDs and the protective effects of DEX are summarized, and the underlying mechanisms are further discussed.

Perioperative dexmedetomidine compared to midazolam in children undergoing open-heart surgery: A pilot randomised controlled trial

Objective

There is a need for evidence on the best sedative agents in children undergoing open heart surgery for congenital heart disease. This study aimed to evaluate the feasibility and safety of dexmedetomidine in this group compared with midazolam.

Design

Double blinded, pilot randomized controlled trial.

Setting

Cardiac operating theatre and paediatric intensive care unit in Brisbane, Australia.

Participants

Infants (≤12 months of age) undergoing their first surgical repair of a congenital heart defect.

Interventions

Dexmedetomidine (up to 1.0mcg/kg/hr) versus midazolam (up to 80mcg/kg/hr), commenced in the cardiac operating theatre prior to surgery.

Main outcome measures

The primary outcome was the time spent in light sedation (Sedation Behavior Scale [SBS] -1 to +1); Co-primary feasibility outcome was recruitment, retention and protocol adherence. Secondary outcomes were use of supplemental sedatives, ventilator free days, delirium, vasoactive drug support, and adverse events. Neurodevelopment and health-related quality of life (HRQoL) were assessed at 12 months post-surgery.

Results

Sixty-six participants were recruited. The number of SBS scores in the light sedation range were greater in the dexmedetomidine group at 24 hours, 48 hours, and overall study duration (0-14 days) versus the midazolam group (24hr: 76/170 [45%] vs 60/178 [34%], aOR 4.14 [95% CI 0.48, 35.92]; 48hr: 154/298 [52%] vs 122/314 [39%], aOR 6.95 [95% CI 0.77, 63.13]; 0-14 days: 597/831 [72%] vs 527/939 [56%], aOR 3.93 [95% CI 0.62, 25.03]). Feasibility was established with no withdrawals or loss to follow-up at 14 days and minimal protocol deviations. There were no differences between the groups relating to clinical, safety, neurodevelopment or HRQoL outcomes.

Conclusions

The use of dexmedetomidine was associated with more time spent in light sedation when compared with midazolam. The feasibility of conducting a blinded RCT of midazolam and dexmedetomidine in children undergoing open heart surgery was also established. The findings justify further investigation in a larger trial.

Clinical trial registration

ACTRN12615001304527.

An adult female patient with single atrium and single ventricle undergoing appendectomy: A case report

Appendicitis is one of the common diseases, and appendectomy is one of the most commonly performed procedures. Single atrium and single ventricle are rare heart diseases, and very few patients survive to adulthood. We report a patient with single atrial and single ventricles undergoing appendectomy with transverse abdominis plane block and dexmedetomidine sedation anesthesia with smooth postoperative appendectomy.

Disruption of hippocampal P2RX2/CaMKII/NF-κB signaling contributes to learning and memory impairment in C57BL/6 mice induced by surgery plus anesthesia in neonatal period

A great number of pediatric patients undergoing varied procedures make neonatal surgery plus anesthesia become a matter of great concern owing to underlying neurotoxicity in developing brain. The authors set out to assess long-term effects of surgery plus anesthesia in mouse model. Six-day-old C57BL/6 mice were randomized to receive either anesthesia with 3% sevoflurane, abdominal surgery under the same anesthesia, or the control condition. These mice were examined of learning and memory at juvenile age in Morris water maze test. The brain tissues of mice were harvested for Western blot analysis, including purinergic receptors P2X family, CaMKII and NF-κB. Another battery of mice were administered with inhibitors of P2RX2/3 (e.g., A317491) into hippocampal dentate gyrus before behavioral testing. We found that neonatal surgery plus anesthesia, but not sevoflurane anesthesia alone, impaired the learning and memory of juvenile mice, as evidenced by delayed escape latency and reduced platform-crossing times. Immunoblotting analysis showed that behavioral abnormalities were associated with increased levels of P2RX2, phosphorylated-CaMKIIβ and activated NF-κB in mouse hippocampus. Injection of A317491 ameliorated the impaired learning and memory of juvenile mice undergoing neonatal surgery plus anesthesia, and it also mitigated the neonatal surgery-induced signaling enhancement of P2RX2/CaMKII/NF-κB. Together, these results indicate that neonatal surgery plus anesthesia may cause long-term cognitive dysfunction, with potential mechanism of increasing P2RX2 and downstream signaling of phosphorylated-CaMKII and NF-κB. Our findings will promote more studies to assess detrimental effects of surgery and accompanying inflammation, diverse anesthetics and even sleeping deprivation on mouse neurodevelopment and neurobehavioral performance.

Reducing Benzodiazepine Exposure by Instituting a Guideline for Dexmedetomidine Usage in the NICU

BACKGROUND

Midazolam is a benzodiazepine sedative used in NICUs. Because benzodiazepine's effects include respiratory depression and potential detrimental developmental effects, minimizing exposure could benefit neonates. Dexmedetomidine is routinely used for sedation in older pediatric populations. We implemented a quality improvement initiative with the aim of decreasing midazolam infusions by 20% through use of dexmedetomidine.

METHODS

A multidisciplinary committee created a sedation guideline that included standardized dexmedetomidine dosing escalation and weaning. Baseline data collection occurred from January 2015 to February 2018, with intervention from March 2018 to December 2019. Percentage of sedation episodes with dexmedetomidine initiated was followed as a process measure. Outcomes measures were percentage of eligible infants receiving midazolam infusions and midazolam-free days per sedation episode. Bradycardia with dexmedetomidine, unplanned extubation rates, and morphine dosage were monitored as balancing measures.

RESULTS

Our study included 434 episodes of sedation in 386 patients. Dexmedetomidine initiation increased from 18% to 49%. The intervention was associated with a significant reduction in midazolam initiation by 30%, from 95% to 65%, with special cause variation on statistical process control chart analysis. Midazolam-free days per sedation episode increased from 0.3 to 2.2 days, and patients receiving dexmedetomidine had lower midazolam doses (1.3 mg/kg per day versus 2.2 mg/kg per day, P = 5.97 × 10-04). Bradycardia requiring discontinuation of dexmedetomidine, unplanned extubation rates, and morphine doses were unchanged.

CONCLUSIONS

Implementation of a quality improvement initiative was successful in reducing the percentage of patients receiving midazolam infusions and increased midazolam-free days per sedation episode, revealing an overall reduction in benzodiazepine exposure while maintaining adequate sedation.

The Influence of Different Dexmedetomidine Doses on Cognitive Function at Early Period of Patients Undergoing Laparoscopic Extensive Total Hysterectomy

Background

This study aims to analyze the influence of different dexmedetomidine doses on cognitive function. It works on early periods of patients undergoing laparoscopic extensive total hysterectomy.

Method

119 patients with gynecological cancer underwent a laparoscopic extensive total hysterectomy. The operation was performed at the Affiliated Women's and Children's Hospital of Xiamen University from January 2019 to June 2020. The score of MoCA and the level of TNF-α, IL-6, S-100β protein, NSE, and GFAP of each group were compared 1 day before and after operation and 3 and 7 days after operation.

Result

In four groups, remifentanil, sufentanil, and propofol were given in the following order: group A > group D > group C > group B. Group A > group D > group C in terms of time spent in the recovery room, extubation, and recovery from anesthesia. The difference between groups B and C was not significant (P > 0.05). Compared with group A, group B scored higher in MoCA at 1 day (T1), 3 days (T2), and 7 days (T3) after operation (P < 0.05). At the same scoring point, the score was group B > group C > group D > group A. The POCD of four groups all occurred at 3 days after surgery. Compared with the T0 point, the level of TNF-α and IL-6 of the four groups at T1 and T2 was significantly increased (P < 0.05). At T3, the level of TNF-α and IL-6 gradually decreased. At various periods, the levels of S-100 protein, NSE, and GFAP in groups B, C, and D were lower than those in group A (P0.05). Group B had a substantially higher rate of bradycardia than the other three groups (P0.05). The incidence of chills, respiratory depression, and restlessness in group A differed significantly from the other three groups (P < 0.05).

Conclusion

Using 0.5 μg/kg dexmedetomidine during the perianaesthesia can effectively reduce anesthetic drugs in patients. They had a laparoscopic extensive complete hysterectomy, which helps to reduce the adverse responses and the occurrence of POCD while also protecting brain function.