Effect of desflurane/remifentanil anaesthesia on glucose metabolism during surgery: a comparison with desflurane/epidural anaesthesia

Effect of sevoflurane versus desflurane on blood glucose level in patients undergoing intracranial neurosurgery: A randomised controlled study

Background and Aims

Anaesthetic agents can affect the neuroendocrine response to surgical stress. Along with affecting other parameters, this can affect blood glucose levels. This study aimed to compare the effect of sevoflurane and desflurane on hourly intraoperative blood glucose levels in non-diabetic patients undergoing intracranial surgery.

Methods

A total of 70 adults (18-65 years) of American Society of Anesthesiologists physical status I and II undergoing elective intracranial surgery for supratentorial and infratentorial lesions were enroled. Patients were randomised to receive either sevoflurane or desflurane as the maintenance anaesthetic agent. The blood glucose level was measured hourly after induction until the completion of surgery. Parametric tests, non-parametric tests, Friedman test, generalised estimating equations, Chi-square test, and Fisher's exact test were used to analyse the data.

Results

In the sevoflurane group, the mean (standard deviation) blood glucose (mg/dL) increased from 93.34 (9.33) at the baseline to a maximum of 102.00 (8.61) at the 9 hours timepoint. This change was statistically significant (P < 0.001). In the desflurane group, the mean blood sugar (mg/dL) increased from 89.34 (9.85) at the baseline to a maximum of 92.37 (9.92) at the 4 hours timepoint and then decreased to 88.50 (0.71) at 9 hours timepoint.

Conclusion

Desflurane caused an initial rise followed by a decline, whereas a gradual increase in intraoperative blood glucose level was seen with sevoflurane use in non-diabetic adult patients undergoing elective neurosurgery. The intraoperative change in blood sugar was statistically significant but was within the normal clinical range.

The effect of glucose control in liver surgery on glucose kinetics and insulin resistance

BACKGROUND & AIMS

Clinical outcome is negatively correlated to postoperative insulin resistance and hyperglycemia. The magnitude of insulin resistance can be modulated by glucose control, preoperative nutrition, adequate pain management and minimal invasive surgery. Effects of glucose control on perioperative glucose kinetics in liver surgery is less studied.

METHODS

18 patients scheduled for open hepatectomy were studied per protocol in this prospective, randomized study. In the treatment group (n = 9), insulin was administered intravenously to keep arterial blood glucose between 6 and 8 mmol/l during surgery. The control group (n = 9) received insulin if blood glucose >11.5 mmol/l. Insulin sensitivity was measured by an insulin clamp on the day before surgery and immediately postoperatively. Glucose kinetics were assessed during the clamp and surgery.

RESULTS

Mean intraoperative glucose was 7.0 mM (SD 0.7) vs 9.1 mM (SD 1.9) in the insulin and control group respectively (p < 0.001; ANOVA). Insulin sensitivity decreased in both groups but significantly (p = 0.03, ANOVA) more in the control group (M value: 4.6 (4.4-6.8) to 2.1 (1.2-2.6) and 4.6 (4.1-5.0) to 0.6 (0.1-1.8) mg/kg/min in the treatment and control group respectively). Endogenous glucose production (EGP) increased and glucose disposal (WGD) decreased significantly between the pre- and post-operative clamps in both groups, with no significant difference between the groups. Intraoperative kinetics demonstrated that glucose control decreased EGP (p = 0.02) while WGD remained unchanged (p = 0.67).

CONCLUSION

Glucose control reduces postoperative insulin resistance in liver surgery. EGP increases and WGD is diminished immediately postoperatively. Insulin seems to modulate both reactions, but mostly the WGD is affected. Intraoperative EGP decreased while WGD remained unaltered.

REGISTRATION NUMBER OF CLINICAL TRIAL

ANZCTR 12614000278639.

Proteostasis in epicardial versus subcutaneous adipose tissue in heart failure subjects with and without diabetes

BACKGROUND

Cardiovascular diseases (CVDs) are leading cause of death and primary cause of morbidity and mortality in diabetic population. Epicardial adipose tissue (EAT) covers the heart's surface and is a source of biomolecules regulating heart and blood vessel physiology. The protective activation of the unfolded protein response (UPR) and autophagy allows the cardiomyocyte reticular network to restore energy and/or nutrient homeostasis and to avoid cell death. However, an excessive or prolonged UPR activation can trigger cell death. UPR activation is an early event of diabetic cardiomyopathies and deregulated autophagy is associated with CVDs.

RESULTS

An upregulation of UPR markers (glucose-regulated protein 78 KDa, glucose-regulated protein 94 KDa, inositol-requiring enzyme 1α, protein kinase RNA-like ER kinase and CCAAT/-enhancer-binding protein homologous protein (CHOP) gene) in EAT compared to subcutaneous adipose tissue (SAT), was observed as well as the UPR-related apoptosis marker caspase-4/procaspase-4 ratio but not in CHOP protein levels. Additionally, levels of ubiquitin and ubiquitinated proteins were decreased in EAT. Moreover, upregulation of autophagy markers (5' adenosine monophosphate-activated protein kinase, mechanistic target of rapamycin, Beclin 1, microtubule-associated protein light chain 3-II, lysosome-associated membrane protein 2, and PTEN-induced putative kinase 1) was observed, as well as an increase in the apoptotic Bim but not the ratio between Bim and the anti-apoptotic Bcl-2 in EAT. Diabetic patients show alterations in UPR activation markers but not in autophagy or apoptosis markers.

CONCLUSION

UPR and autophagy are increased in EAT compared to SAT, opening doors to the identification of early biomarkers for cardiomyopathies and novel therapeutic targets.

Biomimetic electrospun coatings increase the in vivo sensitivity of implantable glucose biosensors

In vivo tissue responses and functional efficacy of electrospun membranes based on polyurethane (PU) and gelatin (GE) as biomimetic coatings for implantable glucose biosensors was investigated in a rat subcutaneous implantation model. Three electrospun membranes with optimized fiber diameters, pore sizes, and permeability, both single PU and coaxial PU‐GE fibers and a solvent cast PU film were implanted in rats to evaluate tissue responses. For functional efficacy testing, four sensor variants coated with the above mentioned electrospun membranes as mass‐transport limiting and outermost biomimetic coatings were implanted in rats. The electrospun PU membranes had micron sized pores that were not permeable to host cells when implanted in the body. However, PU‐GE coaxial fiber membranes, having similar sized pores, were infiltrated with fibroblasts that deposited collagen in the membrane's pores. Such tissue response prevented the formation of dense fibrous capsule around the sensor coated with the PU‐GE coaxial fiber membranes, which helped improve the in vivo sensitivity for at least 3 weeks compared to the traditional sensors in rat subcutaneous tissue. Furthermore, the better in vitro sensor's sensitivity due to electrospun PU as the mass‐transport limiting membrane translated to better in vivo sensitivity. Thus, this study showed that electrospun membranes can play an important role in realizing long in vivo sensing lifetime of implantable glucose biosensors. © 2017 The Authors Journal of Biomedical Materials Research Part A Published by Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1072–1081, 2018.

The Effects of Propofol and Isoflurane on Blood Glucose during Abdominal Hysterectomy in Diabetic Patients

BACKGROUND

Acute hyperglycemia in the perioperative period is associated with significantly increased complications. In few human studies the effects of propofol and inhalational anesthetic on the glucose metabolism were compared. In this study we evaluated the effect of propofol and isoflurane on blood glucose during abdominal hysterectomy in diabetic patients.

METHODS

After approval by the Ethical Committee and written informed consent, thirty 35 to 65 years old diabetic women underwent for elective abdominal hysterectomy under general anesthesia were studied in this randomized single blind clinical trial study. The plasma glucose was maintained at 100 to 180 mg/dL during the operation. Anesthesia protocol was similar in two groups except maintenance of anesthesia that was with infusion of propofol in the propofol group and with isoflurane in the isoflurane group. Blood glucose level and the rate of insulin intake during surgery compared between two groups.

RESULTS

Mean blood glucose before induction of anesthesia did not have significant difference between two groups, but 60 and 90 minutes after starting the operation blood glucose in the propofol group was significantly lower than isoflurane group. Also with using Repeated Measure test, two groups was significantly different according to blood glucose (P=0.045). Mean of administration of insulin during the surgery did not have significant difference between two groups by using repeated measure test and P=0.271. Also mean of bispectral index in different times during the surgery between two groups didn't have significant difference (P=0.35 repeated measure test).

CONCLUSION

Blood glucose increased during maintenance of anesthesia with isoflurane compared to propofol during the surgery.

Effect of intraoperative amino acid infusion on blood glucose under general anesthesia combined with epidural block

AIM

To investigate the effect of intraoperative amino acid infusion on blood glucose in patients under general anesthesia combined with epidural block.

METHODS

36 patients were randomly assigned to receive an intraoperative infusion of 18 compound amino acids (group AA) or lactated Ringer solution (group LR) at 2 ml·kg(-1)·h(-1). Nasopharyngeal temperature, and blood glucose, plasma insulin, C-peptide and glucagon concentrations were measured 30 min before induction (T0), 10 min after induction (T1), 30 min and 2 h after skin incision (T2, T3), and 30 min and 2 h postoperatively (T4, T5).

RESULTS

Nasopharyngeal temperature values, which decreased during surgery in both groups, were significantly higher in group AA than in group LR from T3 to T5. Compared with T0, the blood glucose concentration increased significantly from T2 in group AA and T3 in group LR to T5. Plasma insulin and C-peptide concentrations did not change significantly in group LR, while both increased significantly in group AA from T1 to T4. The plasma glucagon concentration did not change significantly in either group.

CONCLUSION

Intraoperative amino acid infusion in patients under general anesthesia combined with epidural block may accelerate the increase of blood glucose concentration and stimulate insulin secretion, and can alleviate hypothermia during the later period of surgery and postoperatively.

Scientific principles and clinical implications of perioperative glucose regulation and control

Development of hyperglycemia after major operations is very common and is modulated by many factors. These factors include perioperative metabolic state, intraoperative management of the patient, and neuroendocrine stress response to surgery. Acute insulin resistance also develops perioperatively and contributes significantly to hyperglycemia. Hyperglycemia is associated with poor outcomes in critically ill and postsurgical patients. A majority of the investigations use the term "hyperglycemia" very loosely and use varying thresholds for initiating treatment. Initial studies demonstrated improved outcomes in critically ill, postsurgical patients who received intensive glycemic control (IGC) (target serum glucose <110 mg/dL). These results were quickly extrapolated to other clinical areas, and IGC was enthusiastically recommended in the perioperative period. However, there are few studies investigating the value of intraoperative glycemic control. Moreover, recent prospective trials have not been able to show the benefit of IGC; neither an appropriate therapeutic glycemic target nor the true efficacy of perioperative glycemic control has been fully determined. Practitioners should also appreciate technical nuances of various glucose measurement techniques. IGC increases the risk of hypoglycemia significantly, which is not inconsequential in critically ill patients. Until further specific data are accumulated, it is prudent to maintain glucose levels <180 mg/dL in the perioperative period, and glycemic control should always be accompanied by close glucose monitoring.

Faster wash-out and recovery for desflurane vs sevoflurane in morbidly obese patients when no premedication is used

BACKGROUND

The aim of this study was to compare desflurane vs sevoflurane kinetics and dynamics in morbidly obese patients and their recovery profile when no premedication had been used.

METHODS

Twenty-eight unpremedicated obese patients were randomly allocated to receive either sevoflurane (n = 14) or desflurane (n = 14) as the main anaesthetic agent. After induction of anaesthesia, either sevoflurane 2% or desflurane 6% was administered for 30 min via a non-rebreathing circuit. The kinetics of sevoflurane and desflurane were determined by measuring and recording end-tidal samples during this time. The bispectral index was used to indicate the level of hypnosis. At the end of the procedure, the end-tidal concentrations of sevoflurane and desflurane were recorded during the first 5 min after stopping their administration. Time from discontinuation of the anaesthetic drugs to eye opening on verbal command, squeezing the observer's hand on command, extubation, stating their name, giving their correct date of birth, discharge from the recovery room, and duration of the surgery and anaesthesia were also recorded.

RESULTS

The F(A)/F(I) ratio was significantly higher in the desflurane group from the 15th to the 30th min. The wash-out phase was faster for desflurane during the total observation period. When desflurane was used, recovery was also faster.

CONCLUSIONS

Desflurane provides faster wash-in and wash-out than sevoflurane in morbidly obese patients, and recovery is much faster after desflurane administration when no premedication has been used.

Intraoperative Infusion of Amino Acids Induces Anabolism Independent of the Type of Anesthesia

BACKGROUND

The infusion of dextrose in patients receiving epidural and light general anesthesia or general anesthesia alone failed to achieve a positive protein balance. We sought to verify the hypothesis that nutritional supplementation with i.v. amino acids induced a greater protein balance in patients receiving epidural blockade compared with those receiving general anesthesia.

METHODS

Sixteen patients were randomly assigned to receive either general anesthesia with desflurane (control group) or general anesthesia combined with epidural analgesia (EDA group). A primed constant infusion of stable isotope tracers L-[1-(13)C]leucine and [6,6-(2)H2]glucose was started after a 32-h fast before surgery, (3 h of fasted state), and continued for 3 h during surgery during which amino acids were infused i.v. (fed state).

RESULTS

Compared with the fasted state, the endogenous rate of appearance of leucine decreased to a similar extent in both groups, and protein synthesis increased, with no difference between the two groups. Leucine oxidation did not change in either group. After amino acids infusion, endogenous glucose production remained unchanged and glucose clearance decreased in both groups. Blood glucose, plasma cortisol, serum insulin, and glucagon concentrations increased to the same extent in both groups.

CONCLUSIONS

Epidural anesthesia provided no additional benefit beyond the anabolism obtained with amino acids.

Methods of measuring metabolism during surgery in humans: focus on the liver-brain relationship

PURPOSE OF REVIEW

The purpose of this work is to review recent advances in setting methods and models for measuring metabolism during surgery in humans. Surgery, especially solid organ transplantation, may offer unique experimental models in which it is ethically acceptable to gain information on difficult problems of amino acid and protein metabolism.

RECENT FINDINGS

Two areas are reviewed: the metabolic study of the anhepatic phase during liver transplantation and brain microdialysis during cerebral surgery. The first model offers an innovative approach to understand the relative role of liver and extrahepatic organs in gluconeogenesis, and to evaluate whether other organs can perform functions believed to be exclusively or almost exclusively performed by the liver. The second model offers an insight to intracerebral metabolism that is closely bound to that of the liver.

SUMMARY

The recent advances in metabolic research during surgery provide knowledge immediately useful for perioperative patient management and for a better control of surgical stress. The studies during the anhepatic phase of liver transplantation have showed that gluconeogenesis and glutamine metabolism are very active processes outside the liver. One of the critical organs for extrahepatic glutamine metabolism is the brain. Microdialysis studies helped to prove that in humans there is an intense trafficking of glutamine, glutamate and alanine among neurons and astrocytes. This delicate network is influenced by systemic amino acid metabolism. The metabolic dialogue between the liver and the brain is beginning to be understood in this light in order to explain the metabolic events of brain damage during liver failure.