The transcatheter device closure of VSDs requires expensive equipment and treatment costs, and both doctors and patients need to be exposed to X-ray radiation. The operation process is relatively complicated, and the incidence of atrioventricular block is relatively high, which is difficult for many families to accept. To the best of our knowledge, the device closure of VSDs is not advisable in the opinion of some scholars, mainly because of the occurrence of complete atrioventricular block . In fact, the transthoracic device closure of VSDs has been performed in many centers in China, and their clinical experience has been reported with a low incidence of associated atrioventricular block . Increasing numbers of Chinese patients are opting for the transthoracic device closure of VSDs.
Long-lasting opioids are used in cardiac surgery, which may result in the postoperative depression of respiratory function and prolong the duration of mechanical ventilation and the length of ICU stay. Then, the postoperative complications are corresponding increased, and the length of hospital stay is also prolonged. At present, the commonly used clinical anesthesia strategy is to choose the appropriate anesthesia methods and drugs and to provide the appropriate depth of anesthesia that can not only meet the needs of surgery but also facilitate the early recovery of postoperative autonomous breathing and shorten the duration of mechanical ventilation and the length of ICU stay. Combined with the implementation of an appropriate anesthesia strategy for patients who underwent the transthoracic device closure of VSDs, this approach could be more conducive to reducing postoperative complications and shortening both the recovery process and the length of hospital stay.
In this study, sufentanil, which has a high plasma protein binding rate, the strongest analgesic effect, and slight cardiovascular effects, was used in group S. However, its clearance half-life is approximately 150 min, and it is associated with an increase in the intraoperative dose, an increase in the time of postoperative sobriety and delayed extubation . A prospective study by Groesdonk et al. concluded that the use of short-acting opioids and inhaled anesthetics were safe in cardiac surgery . In recent years, the application of remifentanil-based general anesthesia has gradually increased and proven to be safe and effective [12, 13]. Remifentanil is a short-acting opioid receptor agonist that works fast, and the effect wears off quickly after stopping the medicine. After stopping infusion for 3–5 min, spontaneous breathing resumes, which does not change with infusion time or age. Strong analgesic effects, stable hemodynamics, and good controllability make remifentanil especially suitable for fast recovery in children who undergo the transthoracic device closure of VSDs .
Lison and his colleagues found that patients who used remifentanil had a higher pain score 1 h after surgery than those who used sufentanil . Because remifentanil can induce hyperalgesia when discontinued, in the past, it was believed that infants and children had a slow response to pain, and postoperative analgesia was often neglected. However, the pain stress response in adults can also be reflected in children . In addition, in the recovery period of general anesthesia, incision pain and endotracheal intubation stimulation may cause cough, delirium, restlessness, and chills in children, leading to an accelerated heart rate, vascular resistance and increased myocardial oxygen consumption. Therefore, further research is needed to focus on postoperative pain treatment and to formulate a more precise analgesic program.
Dexmedetomidine is a type of α2 adrenal agonist with high efficiency and high selectivity. It has the effects of sedation, analgesia, anti-anxiety and anti-sympathetic nerve and little respiratory inhibition. It can obviously reduce the amount of anesthetic during the perioperative period, effectively relieve the stress response and ease postoperative pain. Studies on the application of dexmedetomidine in cardiovascular surgery have been increasing recently, and most of them show that dexmedetomidine has the effect of myocardial protection and hemodynamic stabilization [17,18,19]. Dexmedetomidine has been increasingly used in pediatric surgery in recent years, but it is still in the exploratory stage [20,21,22]. Related studies have indicated that the pharmacokinetic parameters of dexmedetomidine in children are basically similar to those in adults, but the clearance rate is relatively low because of the immature clearance path in children less than 1 year old . Cheng and his team found that dexmedetomidine infusion in pediatric cardiac surgery with 0.25–0.75 μg/kg/h showed little variability in heart rate and blood pressure . In our study, the infusion dose of dexmedetomidine in group R was 0.5 μg/kg/h, and combined with remifentanil and sevoflurane, the hemodynamics were stable. Dexmedetomidine and remifentanil did not cause bradycardia or hypotension without rapid infusion .
Both groups of children in our study were given intramuscular midazolam before entering the operating room to make them quiet and to produce amnesia. The duration between the patient’s admission to the operating room and undergoing heparinization was more than 1 hour, so local bleeding or hematoma could be avoided. The patients inhaled sevoflurane; blood gas solubility was low, and the depth of anesthesia was controllable, had no stimulation of the respiratory tract, and had a protective effect on acute myocardial injury . Relevant studies confirmed that the use of cisatracurium as a muscle relaxant in pediatric cardiac surgery would not affect the postoperative duration of mechanical ventilation and the length of ICU stay . Cisatracurium was selected as a muscle relaxant in anesthesia induction in both groups, and no additional dose was added in the operation due to the short procedural time.
Table 2 shows that the MAP and HR in group R were significantly lower than those in group S at the time points of endotracheal intubation, skin incision, thoracotomy, incision closure and extubation, demonstrating that dexmedetomidine combined with remifentanil could inhibit the stress response more effectively than sufentanil for the transthoracic device closure of VSDs in pediatric patients. While the hemodynamic indexes and pain scores of the two groups at 1 h and 4 h after extubation showed no significant difference, the amount of postoperative opioids in group R was significantly less than that in group S, which suggests that dexmedetomidine could provide effective and additional postoperative analgesia. Such results are consistent with the study results of Czaja et al., and it could be concluded that dexmedetomidine could provide certain sedative and analgesic effects and prevent and improve remifentanil hyperalgesia during the postoperative recovery stage . Nguyen et al. concluded that dexmedetomidine’s unique properties made it an ideal sedative for patients undergoing cardiac surgery in a retrospective study because it had no respiratory suppression and had the potential to reduce opioid use and anti-sympathetic effects, which might shorten the duration of extubation and ICU observation . Hashemian et al. showed that continuous intravenous pumping of dexmedetomidine at a rate of 0.5 μg/kg/h did not increase the recovery duration of ICU patients, which was also confirmed by our study .
There were some limitations in this study. This was not a prospective randomized controlled study but a retrospective study. The selection of cases might have a certain bias, which would also affect the statistical efficiency of this study. This was a limitation that could not be controlled by the retrospective study. In addition, subjectivity or empiricism in the treatment of children could not be ruled out and needs to be further evaluated by future prospective studies. However, we still believe that the results of this article have some clinical significance. Second, the sample size of this study was relatively small, and it was a single-center study, so the conclusion might be one-sided to some extent. Therefore, we look forward to completing multicenter, larger-sample studies in the future to confirm the reliability of our conclusions.