Introduction
Intravenous sedation (IVS) has been widely applied for relieving patient anxiety and fear concerning dental treatment, stress accompanying surgery, and similar issues. When administering IVS in a patient, in order to prevent aspiration [
1,
2] of the contents of the stomach, patients in our department are instructed to refrain from eating and drinking for 4 h prior to the operation [
3‐
6].
In addition, when performing dental treatment under IVS, several reports [
1,
2] have stated that the risk of vomiting and aspiration is the same as that in general anesthesia, and accordingly, restrictions on eating and drinking are necessary [
3]. However, these dietary restrictions and the surgery itself cause large fluctuations in the blood glucose level, and Sawano et al. [
7] reported that the blood glucose level drops sharply after completion of surgery. Postoperative hypoglycemia is also a factor involved in hemodynamic changes and postoperative complications [
8].
The present study investigated the usefulness of glucose administration as a method of maintaining perioperative glycemic control in patients with dietary restrictions during 4 h prior to impacted mandibular third molar extraction under IVS.
Discussion
In this study, we investigated the usefulness of glucose administration for maintaining perioperative glycemic control in patients with dietary restrictions during 4 h prior to impacted mandibular third molar extraction under IVS. The blood sugar level decreased within the standard range in the control group and the perioperative GL group 90 min after the operation, compared with the preoperative blood glucose level; however, in the postoperative GL group, blood glucose levels were similar to the preoperative levels.
The subjects’ baseline blood glucose levels were 70–110 mg/dL; this range was selected based on the diagnosis of hypoglycemia when the fasting blood glucose level is less than 70 mg/dL, and borderline-type diabetes when the fasting blood glucose level is higher than 110 mg/dL according to the Japanese Clinical Practice Guidelines for Diabetes 2016 published by the Japan Diabetes Society.
In this study, we used a 5% glucose solution with a low risk of hyperglycemia and expected a gradual increase in blood glucose level. The administration rate was set at 4 mg/kg/min with reference to the report of Rosmarin et al. [
12]. This administration rate has no side effects such as hyperglycemia, and the glucose is fully utilized.
During tooth extraction and dental treatment, the blood glucose level increases due to the action of adrenaline present in the local anesthetic solution [
7,
13,
14], but various psychological stressors such as physical stress, anxiety regarding treatment, and feelings of insecurity have also been reported to cause an increase in blood glucose levels during surgery [
7,
14,
15]. In addition, it is known that blood levels of compounds such as catecholamines, cortisol, glucagon, and growth hormone become elevated due to stress reactions, potentially leading to the onset of hyperglycemia [
14,
16‐
18]. However, other reports have stated that this can be suppressed through perioperative pain control measures [
18,
19].
In this study, the postoperative blood glucose level in the control group decreased significantly within the standard range. It was thought that increases in the levels of substances such as catecholamines and cortisol due to sympathetic nerve stimulation were suppressed as patients’ psychological stress was alleviated through the combined use of IVS and pain control by local anesthesia. The subjects’ blood glucose levels did not rise despite the use of an adrenaline-containing local anesthetic solution, which may be attributed to the combination of alleviation of psychological stressors and dietary restriction having a greater effect on blood glucose level compared with the blood glucose-increasing effect of adrenaline. As the subjects of this study were adults without any systemic disease, the decrease in blood glucose level was within the normal range, and no critical deterioration was observed. However, the postoperative blood glucose levels showed a clear reduction even with restriction on eating and drinking for the relatively short period of 4 h.
Blood glucose levels in the perioperative GL group decreased significantly between 60 and 90 min after surgery completion. In healthy adults without diabetes and other diseases, the pancreatic islets’ β cells instantly secrete insulin as the blood glucose level rises [
20,
21]. This study also found that as a result of additional secretion of insulin from the start of glucose administration to 90 min after the operation, and because there were no invasive procedures or stressors and the sedation/analgesia was maintained, catecholamine and cortisol hormones that elevate blood glucose levels were suppressed, resulting in a significant decrease in blood glucose level.
In the postoperative GL group, blood glucose levels increased transiently after glucose administration and subsequently declined, but 90 min after operation, the level recovered to the baseline value and remained stable. This is believed to be due to the additional secretion of insulin after glucose administration as described above, which resulted in regulation of blood glucose in the body to the baseline value in the normal range. In the intergroup comparison, the blood glucose level in the postoperative GL group was significantly higher than that of the control group and perioperative GL group 90 min after the operation.
Since systolic blood pressure, diastolic blood pressure, and heart rate decreased after the end of surgery compared to their respective preoperative levels, sedation was maintained without the need for invasive procedures, and the patients were believed to be in a stress-free state. According to a previous report, the patient’s hemodynamic state is more closely related to the stress caused by surgery than to the amount of local anesthesia to which adrenaline is added during wisdom tooth extraction [
22]. In the present study, sedation was continuing, so there was no increase in systolic and diastolic blood pressure after administration of local anesthesia. However, the heart rate increased after the administration of local anesthesia until the end of surgery. This indicates that adrenaline β1 action increases the heart rate even in a stress-free situation in a sedative state.
This study revealed that the blood glucose level after induction of IVS decreases within the standard range following dietary restriction during the 4 h prior to the start of surgery. Further, administration of glucose after completion of surgery was useful for preventing postoperative hypoglycemia. Nevertheless, if pain and swelling persist after surgery and subjects have difficulty ingesting, there is a risk of further lowering of blood glucose levels. As such, in future studies, it will be necessary to determine the optimal concentration of glucose to be administered and the rate of administration necessary to prevent hypoglycemia. In addition, patients with a history of diabetes often exhibit worsening glycemic control, and clinical manifestations such as hypoglycemia coma are a concern [
8], and the results of this study may represent basic research for effective perioperative management of diabetic patients in whom dental procedures, such as extraction of impacted third molars, are indicated.
However, since only the timing of glucose administration is studied in this research, it is necessary to repeat the research including the concentration of glucose and so on.
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