Effect of sympathetic blockade by spinal anesthesia on pancreatic islet function in man

Comparing the effects of general anesthesia and spinal anesthesia on the serum level of blood sugar in patients undergoing cesarean

Objective

This paper aims to study the influence of both general and spinal anesthesia on blood sugar changes in patients undergoing cesarean.

Methods

This is a single-blind clinical trial study conducted on 60 patients with classes 1 and 2 anesthesia. The patients were divided by chance into the general anesthesia and spinal anesthesia groups (each contains 30 members). The patients in the spinal group were blocked up to the T4 level and similar methods and medicines were also utilized for those in the general anesthesia group.

Results

No significant difference was observed in the blood sugar levels of both groups before and after the operation, but the group, which had utilized the general anesthesia method, had reported with lower levels of blood sugar than the spinal anesthesia group after operation with a significant difference (P < 0.05). A difference has been observed in the levels of blood sugar at 2, 12, and 24 h after the operation in both groups, but it was not a statistically significant difference.

Conclusion

However, none of the mentioned methods had any influence on reduction of blood sugar levels during the recovery or the period after it.

Anesthetic considerations in diabetic patients. Part I: preoperative considerations of patients with diabetes mellitus

Diabetes mellitus is an increasingly common disease that affects people of all ages, resulting in significant morbidity and mortality. Diabetic patients require perioperative care more frequently than their nondiabetic counterparts. The major risk factors for diabetics undergoing surgery are the associated end-organ diseases: cardiovascular disease, autonomic neuropathy, joint collagen tissue, and immune deficiency. Physicians need to pay extra attention to preoperative and preprocedure evaluation and treatment of these diseases to ensure optimal perioperative management.

Anesthesia rapidly suppresses insulin pulse mass but enhances the orderliness of insulin secretory process

Induction of anesthesia is accompanied by modest hyperglycemia and a decreased plasma insulin concentration. Most insulin is secreted in discrete pulses occurring at approximately 6- to 8-min intervals. We sought to test the hypothesis that anesthesia inhibits insulin release by disrupting pulsatile insulin secretion in a canine model by use of direct portal vein sampling. We report that induction of anesthesia causes an abrupt decrease in the insulin secretion rate (1.1 +/- 0.2 vs. 0.7 +/- 0.1 pmol. kg(-1). min(-1), P < 0.05) by suppressing insulin pulse mass (630 +/- 121 vs. 270 +/- 31 pmol, P < 0.01). Anesthesia also elicited an approximately 30% higher increase in insulin pulse frequency (P < 0.01) and more orderly insulin concentration profiles (P < 0.01). These effects were evoked by either sodium thiamylal or nitrous oxide and isoflurane. In conclusion, anesthesia represses insulin secretion through the mechanism of a twofold blunting of pulse mass despite an increase in orderly pulse frequency. These data thus unveil independent amplitude and frequency controls of beta-cells' secretory activity in vivo.

Clinical study of glucose metabolism during partial gastrectomy--comparison between epidural and general anesthesia

Plasma glucose, insulin, glucagon, growth hormone (GH) and cyclic-AMP (C-AMP) were measured in 14 patients undergoing partial gastrectomy under 5 g/hr glucose loading. Seven patients received general anesthesia (GOF; Group G) and the other seven, GO + epidural anesthesia (analgesia Th4-L1; Group E). Blood glucose increased in both groups, although it remained consistently lower in Group E than in Group G. Serum IRI and IRI/glucose ratio appeared consistently higher in Group E than in Group G and a significant difference was found between the two groups at the early period of surgery. The changes in plasma glucagon and GH were found independent of those in glucose. Cyclic-AMP was also consistently higher in Group G than in Group E and a significant difference was observed at the end of anesthesia. These results suggest that epidural anesthesia with 5 g/hr glucose loading may facilitate insulin release from the islet and peripheral blood uptake particularly during the early period of surgery while many other factors such as GH, cortisol and vagal stimulation seemed to be involved in the later period of surgery.

Effects of anesthesia and surgical stress on insulin secretion in man

Surgical stress with inhalation anesthesia is associated with increased circulating catecholamines, hyperglycemia, and impaired insulin secretion. These changes do not occur during surgical stress with spinal anesthesia, suggesting that they are neurally mediated due to pain initiated afferents from the site of tissue trauma. Inhalation anesthesia alone was found to suppress basal insulin levels and the insulin response to intravenous glucose with no significant increase in plasma norepinephrine and a decrease in plasma epinephrine. Thus, these changes in insulin secretion are not attributable to adrenergic mechanisms. In the postoperative period, however, suppressed insulin secretion was found to be correlated with elevated plasma epinephrine concentrations and may, therefore, be mediated by adrenergic mechanisms. Thus, these findings indicate that impaired insulin secretion during surgical stress may have two etiologies--one related to the type of anesthesia used and the other due to adrenomedullary stimulation due to pain.