Arterial Blood Glucose Levels Research Articles

Low-intensity exercise improves cardiac tolerance to ischemia/reperfusion injury in aged female rats with metabolic syndrome.

Metabolic syndrome (MetS) is a group of cardiovascular risk factors which has higher prevalence in the elderly population. Being an aged obese woman with raised arterial blood pressure and blood glucose level might increase the risk of having cardiovascular morbidity or mortality during an attack of myocardial infarction. The present study was designed to evaluate the cardioprotective efficacy of a low intensity swim-exercise program on ischemic reperfusion injury in isolated perfused hearts from aged female rats with MetS. Wistar rats were allocated into three groups: controls, MetS-sedentary, and MetS-exercised. Body weight (BW) and waist circumference were measured with calculation of body mass index (BMI). Blood pressure, fasting blood glucose (FBG) and lipid profile were determined. Cardiac activities of isolated hearts were studied on Langendorff preparation under basal conditions and following ischemia/reperfusion (I/R), and the level of cardiac tissue nitrite was also assessed. MetS-exercised rats showed restoration of control values for BW, BMI, waist circumference, visceral fat, FBG, plasma lipid profile and left ventricular nitrite content. Meanwhile, arterial blood pressure was significantly lower than both controls and MetS-sedentary rats. These findings suggest that a short-term, low-intensity exercise program can improve cardiac tolerance to I/R injury possibly by ameliorating the high-risk cardiovascular components of the MetS.

Dexmedetomidine versus fentanyl on stress response and pain control in adult patients undergoing laparoscopic surgery

Laparoscopic procedures are widely indicated; however, the ideal approach for pain control remains debatable. This trial compared between the effects of dexmedetomidine and fentanyl infusion on stress response and pain control in patients undergoing elective laparoscopic surgeries. A prospective randomized double-blinded comparative study included 82 adult participants randomly allocated into two equal-sized groups. Group D received 1 µg/kg of intravenous (IV) dexmedetomidine over 10 min as a loading dose just before induction of anesthesia, then 0.2–0.7 µg/kg/h till 10 min before the surgery ends. Group F received 1 µg/kg of IV fentanyl as a loading dose, then 0.2–0.7 µg/kg/h. Primary objective was postoperative analgesic consumption in 24 h. Collected data were heart rate (HR), mean arterial blood pressure (MAP), blood glucose and serum cortisol levels, visual analogue score (VAS), and the perioperative analgesic consumption. Group D consumed significantly less postoperative morphine doses in 24 h (p = 0.003), and 41.5% of Group D patients did not need any postoperative morphine. Group D had better-controlled hemodynamic changes 5 min post-extubation (HR and MAP p = 0.021 and p = 0.022 respectively), showed significantly less postoperative stress response as manifested in the blood glucose and serum cortisol levels 4 h postoperatively (p = 0.006 and p = 0.001 respectively), and less VAS pain scores at early and late postoperative periods. Intraoperative IV dexmedetomidine administration as a sole analgesic agent for patients undergoing elective laparoscopic surgeries serves as a convenient anesthetic approach, since it provided a good postoperative pain control, and reduced the surgical stress response and the perioperative analgesic consumption.

Monitored Anesthetic Care Combined with Scalp Nerve Block in Awake Craniotomy: An Effective Attempt at Enhanced Recovery After Neurosurgery

Enhanced recovery after surgery has been attempted in neurosurgery at a greater rate. However, concern exists regarding the feasibility of using enhanced recovery after neurosurgery (ERANS). How to manage available resources to safely perform ERANS and improve clinical outcomes has been the subject of much debate and discussion. Owing to the paucity of data available on the use of ERANS protocols, we performed the present feasibility study. We studied the outcomes of the protocols used within a tertiary referral neurosurgery center. Data from patients who had undergone awake craniotomy within an ERANS protocol were prospectively recorded in our institution from September 2017 to December 2018. We also evaluated the safety and effectiveness of the novel ERANS protocol. A total of 20 patients (mean age, 49.5 ± 17.8 years) were included in the present study. Intraoperative hypertension, hypotension, and bradycardia were present in 4 (20%), 1 (5%), and 1 (5%) patient, respectively. The postoperative morbidities included epilepsy in 1 (5%), pain in 3 (15%), and nausea or vomiting in 2 (10%). No significant changes had occurred in the mean arterial pressure, heart rate, blood glucose, or lactic acid level throughout the procedure. The median length of intensive care unit stay and postoperative hospital stay were 1 and 9.5 days, respectively. No 30-day readmissions or reoperations occurred during the present study. Applying an ERANS protocol was feasible, associated with a low incidence of complications, and acceptable intensive care unit and postoperative hospital lengths of stay. The findings from the present study might provide a new approach for the further research of ERANS.

Comparative study of physiological changes of nil per oral vs glucose water vs free water in patients undergoing laparoscopic cholecystectomy: A randomized prospective study

The aim of this study was to compare the effect of ingestion of clear water and glucose water over 10 hours NPO in elective laparoscopic cholecystetctomy surgery.An observational study was conducted in Sir Sunderlal hospital, Banaras Hindu University. The study included ASA I-II patients undergoing laparoscopic cholecystectomy surgery. Patients undergoing general anaesthesia were included in the study. Among three groups, the control fasted in accordance to nil per os for 10 hours, second and third group received 200 mL of clear water and 200 ml of glucose water, respectively 2 hours before the surgery. Arterial Blood Gas analysis and blood glucose level was done in the immediate post-operative period. Arterial pH, serum electrolytes, serum lactate and blood glucose levels were compared for the above 3 groups. Results were given as mean ± SD. Data collected were analysed using Student’s t-test. Differences were considered statistically significant if P values were <0.05. A total of 45 patients were included and 15 patients each were randomly assigned to one of the 3 groups. Patients who had 200 ml of clear water before surgery had lesser variation in serum K+ [p=0.045] and serum lactate level [p=0.001] than NPO. Patients fed with 200 ml of glucose water before surgery had lesser variation in serum K+ level [p=0.02], serum lactate level [p<0.001], in Random Blood Sugar level [p<0.001] and no episode of hypoglycaemia observed as compared to NPO. Patients given 200 ml of glucose water exhibited lesser variation in serum lactate level [p=0.004], in RBS level [p<0.001] and no hypoglycaemic episode recorded contrary to those supplied with 200 mL of clear water. More fluctuations in extreme values of pH and serum electrolytes values observed in group A. Episodes of hypoglycaemia found more frequent in NPO and patients that received only clear water. No significant side-effects were observed in any group.We conclude that it is safe to give clear drinks 2 hours prior to surgery. Prolonged withholding of oral fluid may cause imbalance in pH, serum electrolytes and hypoglycaemia. The finding confirms the recent ASA guidelines which no longer recommends an indiscriminate ‘NPO after midnight’ policy.

Stepwise lactate kinetics in critically ill patients: prognostic, influencing factors, and clinical phenotype

BackgroundTo investigate the optimal target e of lactate kinetics at different time during the resuscitation, the factors that influence whether the kinetics achieve the goals, and the clinical implications of different clinical phenotypes.MethodsPatients with hyperlactatemia between May 1, 2013 and December 31, 2018 were retrospectively analyzed. Demographic data, basic organ function, hemodynamic parameters at ICU admission (T0) and at 6 h, 12 h, 24 h, 48 h, and 72 h, arterial blood lactate and blood glucose levels, cumulative clinical treatment conditions at different time points and final patient outcomes were collected.ResultsA total of 3298 patients were enrolled, and the mortality rate was 12.2%. The cutoff values of lactate kinetics for prognosis at 6 h, 12 h, 24 h, 48 h, and 72 h were 21%, 40%, 57%, 66%, and 72%. The APACHE II score, SOFA score, heart rate (HR), and blood glucose were risk factors that correlated with whether the lactate kinetics attained the target goal. Based on the pattens of the lactate kinetics, eight clinical phenotypes were proposed. The odds ratios of death for clinical phenotypes VIII, IV, and II were 4.39, 4.2, and 5.27-fold of those of clinical phenotype I, respectively.ConclusionStepwise recovery of lactate kinetics is an important resuscitation target for patients with hyperlactatemia. The APACHE II score, SOFA score, HR, and blood glucose were independent risk factors that influenced achievement of lactate kinetic targets. The cinical phenotypes of stepwise lactate kinetics are closely related to the prognosis.

A comparison of arterial blood glucose and peripheral blood glucose levels in critically ill patients: measurements using the arterial blood gas analyzer and the rapid glucose meter.

This study explored the differences, correlation, and consistency between blood glucose levels measured using an arterial blood gas analyzer and a rapid blood glucose meter in critically ill patients. A total of 73 critically ill patients admitted to the Department of Critical Care Medicine, from October to December 2016 were enrolled in this study. The patient's arterial blood glucose was measured by arterial blood gas analyzer, while peripheral blood glucose was measured by a rapid blood glucose meter (via the non-infusion limb). The correlation between indicators was analyzed using the linear regression model. Bland-Altman was performed to evaluate the agreement of the two methods for measuring blood glucose. P<0.05 was considered statistically significant. The blood glucose values measured using the arterial blood gas analyzer was significantly different from the values obtained using the rapid blood glucose meter (P=0.000). Regression analysis showed that R2 was 0.857 and β was 0.324 (P=0.000). Bland-Altman plot analysis showed that arterial blood glucose values obtained using the arterial blood gas analyzer were higher than the peripheral blood glucose values obtained using the rapid blood glucose meter on the non-infused limb, with 2.74% of dots lying outside the 95% limit of agreement and the maximum absolute value (2.30 mmol/L) of blood glucose difference within the limit of agreement. The blood glucose levels measured using the two different methods showed good agreement. The difference in blood glucose values measured using the two different measurement methods was statistically significant, but the maximum absolute value (2.30 mmol/L) of blood glucose difference within the limit of agreement, which is acceptable in the clinical setting. In clinical care, it is not necessary to repeat a measure of the patient's capillary blood glucose (CBG) using the rapid blood glucose meter after the blood glucose levels have been measured with the arterial blood gas analyzer, thereby reducing the associated pain and inconvenience for the patients.

Incidence and Associated Risk Factors for Lactic Acidosis Induced by Linezolid Therapy in a Case-Control Study in Patients Older Than 85 Years.

Background: Serum lactic acid is considered a prognostic indicator in critically ill patients. However, studies on linezolid-induced lactic acidosis (LILA) are still limited. Individuals older than 85 years old (very elderly) have limited capacity for organ compensation, and LILA data from these patients are lacking. In this study, we evaluated the risk factors for LILA in patients older than 85 years and established a risk prediction model for geriatric practice.Methods: In this retrospective cohort study, blood gas analysis data and arterial lactate levels were monitored in patients older than 85 years during the use of teicoplanin or linezolid. After propensity score matching analyses, we compared the incidence of lactic acidosis between the teicoplanin and linezolid therapy groups and identified the risk factors of LILA.Results: The incidence of lactic acidosis was found to be much lower in the group receiving teicoplanin than those receiving linezolid therapy (0 vs. 35.7%; p < 0.0001). A duration of linezolid therapy ≥ 9 days [odds ratio (OR), 3.541; 95% confidence interval (CI), 1.161–10.793; p = 0.026], an arterial blood glucose level ≥ 8 mmol/L (OR, 4.548; 95% CI, 1.507–13.725; p = 0.007), and a high sequential organ failure assessment score (OR, 1.429; 95% CI, 1.213–1.685; p < 0.0001) were risk factors for LILA. The constructed risk model could be used to predict LILA (area under the curve, 0.849; specificity, 65.1%; sensitivity, 91.4%, with a negative predictive value of 93.2% and a positive predictive value of 59.3%).Conclusions: LILA can occur in patients older than 85 years after a relatively shorter duration of linezolid therapy. Therefore, close monitoring of blood gas and arterial lactate levels during linezolid therapy in the very elderly population is necessary.

Synergistic Effect of β-alanine and Aprotinin on Mesenteric Ischemia

BackgroundAcute mesenteric ischemia arises through sudden interruption of mesenteric blood flow, mostly due to an occlusion of the superior mesenteric artery and is associated with a high mortality of approximately 50% to 90%. In previous studies, the single application of β-alanine or aprotinin caused an ameliorated intestinal damage but without any systemic effects. MethodsTo analyze the combined effect of β-alanine and aprotinin on acute ischemia and reperfusion of the small intestine, a model with anesthetized rats was used. Ischemia and reperfusion were initiated by occluding and reopening the superior mesenteric artery. After 120 min of ischemia and 180 min of reperfusion, the intestine was analyzed for tissue damage, the activity of the saccharase, and accumulation of granulocytes. In addition, systemic and metabolic as well as inflammatory parameters were measured in blood at certain points in time. ResultsThe combination of β-alanine and aprotinin resulted in a clearly stabilized mean arterial blood pressure and blood glucose level during the reperfusion period. Furthermore, the combined administration resulted in significantly reduced tissue damage parameters, cytokine and cell-free hemoglobin concentrations in blood plasma. In addition, the damage to the small intestine was significantly attenuated, so that the animals ultimately survived the entire test period because of the administration of both substances. ConclusionsOverall, the simultaneous application of both substances leads to a synergistic protection without the occurrence of undesirable side effects. The combined usage of β-alanine and aprotinin can be seen as a promising approach to inhibit the onset of acute mesenteric ischemia.

Utility of bedside artificial pancreas for postoperative glycemic control in cardiac surgery.

In the present single-center retrospective study, we analyzed arterial blood glucose levels for 15h after surgery in 69 patients treated using the bedside artificial pancreas and in 160 patients treated with continuous intravenous insulin infusion using a scale that adjusts for current blood glucose level, glycemic fluctuation, and insulin dose. Hypoglycemia (arterial blood glucose level < 70mg/dL) was not observed in any case. Patients in the group treated using the bedside artificial pancreas showed lower mean, maximum, and minimum blood glucose levels and glycemic variability and shorter treatment duration in the intensive care unit than patients treated with continuous intravenous insulin infusion. Notably, these results were not affected by diabetes status or differences in operative procedures. Analysis of patients undergoing isolated coronary artery bypass grafting surgery revealed that the incidence of surgical site complications composite with infection and dehiscence was lower. In cardiac surgery, postoperative treatment using bedside artificial pancreas is a novel therapy that improves hyperglycemia and glycemic variability, without hypoglycemia, and is, therefore, an attractive strategy for future surgeries.

Chemical exchange sensitive MRI of glucose uptake using xylose as a contrast agent.

Glucose and its analogs can be detected by CEST and chemical exchange spin-lock (CESL) MRI techniques, but sensitivity is still a bottleneck for human applications. Here, CESL and CEST sensitivity and the effect of injection on baseline physiology were evaluated for a glucose analog, xylose. The CEST and CESL sensitivity were evaluated at 9.4 T in phantoms and by in vivo rat experiments with 0.5 and 1 g/kg xylose injections. Arterial blood glucose level was sampled before and after 1g/kg xylose injection. The effect of injection on baseline neuronal activity was measured by electrophysiology data during injections of saline, xylose, and 2-deoxy-D-glucose. In phantoms, xylose shows similar chemical exchange sensitivity and pH-dependence with that of glucose. In rat experiments with a bolus injection, CESL shows higher sensitivity in the detection of xylose than CEST, and the sensitivity of xylose is much higher than glucose. Injection of xylose does not significantly affect blood glucose level and baseline neural activity for 1-g/kg and 0.6-g/kg doses, respectively. Due to its relatively high sensitivity and safety, xylose is a promising contrast agent for the study of glucose uptake.

Effects of early postnatal sevoflurane exposure on oligodendrocyte maturation and myelination in cerebral white matter of the rat

General anaesthesia may impose significant neurocognitive risks on the developing brain. As brain injury in preterm neonates has a particular predilection for cerebral white matter, we aimed to evaluate the effects of sevoflurane on oligodendrocyte maturation and myelination in a preterm-equivalent rat model. Two-day-old postnatal (P2) Sprague-Dawley rats were exposed to 3.3 % (approximately 1 minimum alveolar concentration [MAC]) or 4.9 % (approximately 1.5 MAC) sevoflurane for 2 h. Physiologic parameters were measured at the end of sevoflurane anaesthesia. Oligodendrocyte proliferation, maturation, and myelination were evaluated by immunofluorescence with specific markers at different time points. Open field test and Morris water maze tests were performed to access behavior changes from P29 to P36. Arterial blood gases values and blood glucose levels were within the normal physiologic range. As compared to control, 4.9 %, but not 3.3 % sevoflurane disturbed oligodendrocyte maturation at P14, resulting in hypomyelination and axonal damage in cerebral white matter at P28. Rats exposed to 4.9 %, but not 3.3 % sevoflurane showed decreased explorative activity and increased anxiety-like behaviour, as well as learning and memory impairments. Furthermore, 4.9 %, but not 3.3 % sevoflurane inhibited oligodendrocyte proliferation in the developing white matter of the rat brain at 12 h post-anaesthesia, with further evidence of widespread reactive astrogliosis. High concentration of sevoflurane (4.9 %) exposure in early postnatal rats may disrupt oligodendrocyte maturation and myelination. Our study has aimed a spotlight on the need for safe and rational use of analgesics in neonates, especially preterm infants.

A Study to Compare Arterial, Capillary and Venous Blood Glucose levels in Patients with Hypotension on Vasopressor versus Normotensive Patients

A Study to Compare Arterial, Capillary and Venous Blood Glucose levels in Patients with Hypotension on Vasopressor versus Normotensive Patients

Is elevated blood glucose a marker of occult tissue hypoperfusion in off-pump coronary artery bypass grafting?

Context:Hyperglycemia has been found to occur during myocardial infarction and cardiac surgery even in nondiabetic patients. These being essentially stressful processes associated with hypoperfusion, we decided to find a possible relationship between the occurrence of global tissue hypoperfusion (GTH) and elevated blood glucose level in adult nondiabetic patients undergoing elective off-pump coronary artery bypass grafting (CABG).Aims:This study aims to observe for the occurrence of global tissue hypoperfusion and its effect on blood glucose level and whether raised blood glucose level can be used as a marker for GTH.Design:Prospective, observational study.Settings:Cardiothoracic operation theater and intensive care unit of a tertiary care teaching hospital.Materials and Methods:The occurrence of global tissue hypoperfusion were detected with the help of combined markers of mixed venous oxygen saturation and arterial lactate level at various perioperative study points together with arterial blood glucose level. Blood glucose level compared between the patients with and without GTH.Statistical Analysis Used:Numerical variables were compared between groups by Student's t-test and categorical variables by Fisher's exact test. Two-tailed P ≤ 0.05 was considered for statistically significant.Results:The incidence of GTH was 67%. Blood glucose level was raised in patients with GTH at some study time points but with poor sensitivity and specificity values.Conclusions:Global tissue hypoperfusion is a common occurrence in even nondiabetic patients undergoing elective off-pump CABG. A relationship exists between rise in blood glucose level and global tissue hypoperfusion in such patients, although it cannot be viewed as marker of the same.

Protective effect of alpha-lipoic acid on progression of cataract formation in fructose-induced experimental cataract

Cataract is the leading cause of ocular blindness worldwide and exacerbated by various systemic disorders, including diabetes and hypertension. The present study was designed to investigate the protective effects of alpha-lipoic acid (LA) against fructose-induced experimental cataract. Sprague-Dawley albino rats (150–180g) were assigned to groups each containing six animals. Group I (normal) received 0.3% carboxymethyl cellulose (10ml/kg/day, p.o.) by gavage. Group II (fructose control) received carboxymethyl cellulose by gavage and 10% (w/v) fructose solution in place of drinking water. Group III and IV received LA at two dose levels 20 and 40mg/kg/day orally by gavage respectively, concurrent with fructose solution (10% w/v) for eight consecutive weeks. Mean arterial pressure, blood glucose level, and lenticular opacity were examined biweekly and pathophysiological parameters in eye lenses were evaluated after eight weeks of the experimental protocol. The eight weeks administration of LA (20 and 40mg/kg) concurrent with fructose solution significantly reduced the mean arterial pressure and blood glucose level. Additionally, lipoic acid treatment led to significant alleviation in lens antioxidants (CAT, SOD, GPx, and GSH), total protein, and Ca2+ ATPase activity. Moreover, a significant reduction in lens MDA and Ca2+ was seen as compared to fructose control group. Ophthalmoscope observations indicated that LA treatment delayed the onset and progression of cataract against the fructose treatment. The results suggest that alpha-lipoic acid supplement play a beneficial role in the management of diabetes and hypertension associated cataractogenesis.

Comparative aspects of respiratory support via laringeal air ducts and endotracheal tube for video-assisted onkothoracic operations

To improve patient 's recovery after video-assisted thoracoscopic lobectomies (VATSL) by laryngeal mask using. This is a comparative analysis of 74 patients underwent VATSL. In 37 patients anaesthesia consisted of sevoflurane and fentanyl, myorelaxant, respiratory support via independent ventilation of either lung. In another 37patient 's anaesthesia protocol included respiratory support performed via laryngeal mask, propofol infusion and epidural analgesia with ropivacaine 0,2% and fentanyl. During the operation in both groups we evaluated hemodynamic, arterial blood gases, leukocytes, glucose and cortisol blood level, time to consciousness restoration (Aldrete-score) and time to discharge from ICU and duration of hospital stay, frequency of complications. Patients with ventilation through laryngeal mask showed a statistically lower stress-reaction, avoided bronchoscopy with BAL and frequency of complications. Duration of inhospital stay in patients with laryngeal mask was 7±1,3 days; in intubated patients was 11±3,2 days. In case of ventilation through the laryngeal mask hyper dynamic state of circulation, glycemia, leukocytes, cortisol blood level and arterial blood pH were lower, whereas Pa CO₂ increase. The number of bronchoscopy with BAL and time to discharge from ICU and from hospital not having risk of postoperative complications --lower.

Effects of pressure-controlled and volume-controlled ventilation on respiratory mechanics and systemic stress response during prone position.

BackgroundProne position during general anesthesia for special surgical operations may be related with increased airway pressure, decreased pulmonary and thoracic compliance that may be explained by restriction of chest expansion and compression of abdomen. The optimum ventilation mode for anesthetized patients on prone position was not described and studies comparing volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) during prone position are limited. We hypothesized that PCV instead of VCV during prone position could achieve lower airway pressures and reduce the systemic stress response. In this study, we aimed to compare the effects of PCV and VCV modes during prone position on respiratory mechanics, oxygenation, and hemodynamics, as well as blood cortisol and insulin levels, which has not been investigated before.MethodsFifty-four ASA I-II patients, 18–70 years of age, who underwent percutaneous nephrolithotomy on prone position, were randomly selected to receive either the PCV (Group PC, n = 27) or VCV (Group VC, n = 27) under general anesthesia with sevoflurane and fentanyl. Blood sampling was made for baseline arterial blood gases (ABG), cortisol, insulin, and glucose levels. After anesthesia induction and endotracheal intubation, patients in Group PC were given pressure support to form 8 mL/kg tidal volume and patients in Group VC was maintained at 8 mL/kg tidal volume calculated using predicted body weight. All patients were maintained with 5 cmH2O PEEP. Respiratory parameters were recorded during supine and prone position. Assessment of ABG and sampling for cortisol, insulin and glucose levels were repeated during surgery and 60 min after extubation.ResultsP-peak and P-plateau levels during supine and prone positions were significantly higher and P-mean and compliance levels during prone position were significantly lower in Group VC when compared with Group PC. Postoperative PaO2 level was significantly higher in Group PC compared with Group VC. Cortisol levels were increased with surgery in both groups (p < 0.05) and decreased to baseline levels in Group PC while remained high in Group VC in the early postoperative period. Cortisol levels were significantly higher in Group VC during surgery and in the early postoperative period compared with Group PC.ConclusionWhen compared with VCV mode, PCV mode is associated with lower P-peak and P-plateau levels during both supine and prone positions, better oxygenation postoperatively, lower blood cortisol levels during surgery in prone position and in the early postoperative period. We concluded that PCV mode might be more appropriate in prone position during anesthesia.

Preparation and preliminary characterization of recombinant neurolysin for in vivo studies

The goal of this study was to produce milligram quantities of pure, catalytically active, endotoxin-free recombinant neurolysin (rNln) in standard laboratory conditions for use as a research tool. To this end, we transformed E. coli cells with a plasmid construct for polyhistidine-tagged rNln, selected a high-expressing clone and determined the optimal time-point for translation of rNln. rNln was purified to homogeneity from the soluble pool of the cell lysate using Ni-NTA affinity and size-exclusion chromatography, followed by removal of endotoxins. Using this protocol ∼3mg pure, catalytically active and nearly endotoxin-free (≈0.003EU/μg protein) rNln was reproducibly obtained from 1l of culture. Lack of cytotoxicity of rNln preparation was documented in cultured mouse cells, whereas stability in whole mouse blood. Intraperitonealy administered rNln in mice reached the systemic circulation in intact and enzymatically active form with Tmax of 1h and T1/2 of ∼30min. Administration of rNln (2 and 10mg/kg) did not alter arterial blood pressure, heart rate, body temperature and blood glucose levels in mice. These studies demonstrate that the rNln preparation is suitable for cell culture and in vivo studies and can serve as a research tool to investigate the (patho)physiological function of this peptidase.

Does glycemic level affect neurologic outcomes during cardiopulmonary bypass?

Perioperative hyperglycaemia, aggravated by cardiopulmonary bypass (CPB), is associated with adverse outcomes. Increased potential for stroke in these patients may be improved by different interventions. Blood glucose level changes as an intrinsic response to both stress and extrinsic sources; might affect early mortality and morbidity. In this study, we tried to identify a relationship existence between cerebral arterial oxygen saturation (rSO2) and blood glucose levels, and thus; evaluate changes in rSO2 caused by changes in blood glucose levels measured at predetermined time points of CPB. Forty six patients with American Society of Anaesthesiologists (ASA) physical status at least III and even IV, undergoing elective open cardiac surgery were prospectively studied. Preparation for surgery, anaesthesia and perioperative vital data monitoring (five-channel) ECG, pulse oximetry, capnography, nasopharynx and rectal temperature, invasive arterial blood pressure, central venous pressure and near-infrared spectroscopy (NIRS) monitoring were done in the same standardised way for each patient. The Mini-Mental State Examination (MMT) questionnaire was used for these patients before and 24 hours after the operation to assess neurologic adverse effects. NIRS values and blood glucose levels were sampled at the following stages of the intervention: the reference level (T0) was obtained immediately after cannulation of the arterial system and before anaesthesia; the second sample (T1) was taken 20 min after anaesthesia was introduced; the third sample (T3) was taken after 20 min of the aortic cross-clamp; the fourth sample (T4) was taken 20 min after the removal of the aortic cross-clamp; and the final sample (T5) was obtained 24 h after the surgery. No statistically signifi;cant relationship was found between changes in rSO2 and changes in blood glucose levels before surgery, after anaesthesia, ischemia, reperfusion, and surgery, in either diabetic or non-diabetic patients. Our findings showed increase in blood glucose levels and decrease in rSO2 as expected in ischemia and reperfusion periods of bypass. There was no significant difference between preoperative and postoperative MMT values of diabetic and non-diabetic patients. Cerebral oxygen saturation measured by NIRS may be a useful monitorization in open cardiac surgery. Our fndings suggests that hyper/hypoglycemia during surgery did not reflect changes in cerebral oxygenation, thus neurologic outcomes when other variables remained constant. Further studies using this approach in different surgeries and patient groups are needed.

Hypoglycaemia Modulates The Patterns Of Ventilatory Responses Evoked By Chemoreceptor Stimulation

Hypoglycaemia (HG) evokes a counter‐regulatory response to restore arterial blood glucose levels. Additionally, HG has also been shown to evoke an increase in ventilation whilst maintaining normocapnia suggesting the ventilation remained matched to metabolism. Whilst it has been shown that HG induces an increase in CO2 sensitivity, there is a lack of data on how HG may modulate the pattern of breathing in normoxia as well as during chemoreceptor‐mediated responses. Whole body plethysmography (WBP) allows the measurement of respiratory variables in conscious unanesthetised animals under baseline conditions as well as during hypercpanic or hypoxic challenges.WBP was used to measure the ventilatory responses to air breathing (21% O2), acute hypoxia (10% O2) and hypercapnia (8% CO2) in male Wistar rats that had free access to food, were fasted overnight or were made hypoglycaemic by insulin injection. Blood glucose levels tended to be lower after fasting but not significantly (8±0.8mM vs 6.8±0.5mM), however, insulin injection did induce a significant HG (3.8±0.5mM). HG induced an increase in response to hypercapnia primarily by increasing tidal volume changes. Further, HG induced an increase in expiratory time (Te) that was abolished during hypercapnia but remained present during hypoxia with no changes in inspiratory time (TI). The TI:TE ratio increased in both hypercapnia and hypoxia, however, the magnitude of increase was only dependent on glycaemic state with hypercapnia.HG induces changes in baseline ventilation but also interacts with the response to a hypercapnic stimulus but not a hypoxic stimulus. The dependency on blood glucose levels of the TI:TE increase during hypercapnia may reflect the coordinated neuroendocrine responses seen during the counter‐regulatory response to HG and matching ventilation to an increased metabolic rate.Support or Funding InformationA. Mobley carried out this work in support of his MRes degree

Effects of pressure-controlled and volume-controlled ventilation on respiratory mechanics and systemic stress response during laparoscopic cholecystectomy

Pressure-controlled ventilation (PCV) is less frequently employed in general anesthesia. With its high and decelerating inspiratory flow, PCV has faster tidal volume delivery and different gas distribution. The same tidal volume setting, delivered by PCV versus volume-controlled ventilation (VCV), will result in a lower peak airway pressure and reduced risk of barotrauma. We hypothesized that PCV instead of VCV during laparoscopic surgery could achieve lower airway pressures and reduce the systemic stress response. Forty ASA I-II patients were randomly selected to receive either the PCV (Group PC, n = 20) or VCV (Group VC, n = 20) during laparoscopic cholecystectomy. Blood sampling was made for baseline arterial blood gases (ABG), cortisol, insulin, and glucose levels. General anesthesia with sevoflurane and fentanyl was employed to all patients. After anesthesia induction and endotracheal intubation, patients in Group PC were given pressure support to form 8 mL/kg tidal volume and patients in Group VC was maintained at 8 mL/kg tidal volume calculated using predicted body weight. All patients were maintained with 5 cmH2O positive-end expiratory pressure (PEEP). Respiratory parameters were recorded before and 30 min after pneumoperitonium. Assessment of ABG and sampling for cortisol, insulin and glucose levels were repeated 30 min after pneumoperitonium and 60 min after extubation. The P-peak levels observed before (18.9 ± 3.8 versus 15 ± 2.2 cmH2O) and during (23.3 ± 3.8 versus 20.1 ± 2.9 cmH2O) pneumoperitoneum in Group VC were significantly higher. Postoperative partial arterial oxygen pressure (PaO2) values are higher (98 ± 12 versus 86 ± 11 mmHg) in Group PC. Arterial carbon dioxide pressure (PaCO2) values (41.8 ± 5.4 versus 36.7 ± 3.5 mmHg) during pneumoperitonium and post-operative mean cortisol and insulin levels were higher in Group VC. When compared to VCV mode, PCV mode may improve compliance during pneumoperitoneum, improve oxygenation and reduce stress response postoperatively and may be more appropriate in patients having laparoscopic surgery.