Metin Alkan

Dexmedetomidine protects from post-myocardial ischaemia reperfusion lung damage in diabetic rats

Objective Diabetic complications and lipid peroxidation are known to have a close association. Lipid peroxidation commonly occurs at sites exposed to ischaemia, but distant organs and tissues also get damaged during ischaemia/reperfusion (I/R). Some of these targets are vital organs, such as the lung, liver, and kidney; the lung is the most frequently affected. The aim of our study was to investigate the effects of dexmedetomidine on I/R damage in lung tissue and on the oxidant/anti-oxidant system in diabetic rats. Material and methods Diabetes was induced with streptozotocin (55 mg/kg) in 18 Wistar Albino rats, which were then randomly divided into three groups (diabetes control (DC), diabetes plus ischaemia-reperfusion (DIR), and diabetes plus dexmedetomidine-ischaemia/reperfusion (DIRD)) after the effects of diabetes were clearly evident. The rats underwent a left thoracotomy and then ischaemia was produced in the myocardium muscle by a left anterior descending artery ligation for 30 min in the DIR and DIRD groups. I/R was performed for 120 min. The DIRD group received a single intraperitoneal dose of dexmedetomidine (100 µg/kg); the DIR group received no dexmedetomidine. Group DC was evaluated as the diabetic control group and also included six rats (C group) in which diabetes was not induced. These mice underwent only left thoracotomy and were closed without undergoing myocardial ischaemia. Histopathological changes, activities of catalase (CAT) and glutathione-S-transferase anti-oxidant enzymes, and malondialdehyde (MDA) levels were evaluated in the lung tissues of all rats. Results Neutrophil infiltration/aggregation was higher in the DIR group than in the C, DC, and DIRD groups (p=0.001, p=0.013, and p=0.042, respectively). The lung injury score was significantly higher in the DIR group than in the C and DC groups (p<0.0001 and p=0.024, respectively). The levels of MDA were significantly higher in the DIR group than in the C and DIRD groups. CAT activity was significantly higher in the DIR group than in the DIRD and C groups. Conclusion Our results confirm that dexmedetomidine has protective effects against the lung damage resulting from I/R in diabetic rats. Future studies conducted to evaluate the effects of the use of dexmedetomidine on damage to various organs following different I/R durations may help understanding possible protective effects of dexmedetomidine and underlying mechanisms in tissue damage related to I/R injury.Objective Diabetic complications and lipid peroxidation are known to have a close association. Lipid peroxidation commonly occurs at sites exposed to ischaemia, but distant organs and tissues also get damaged during ischaemia/reperfusion (I/R). Some of these targets are vital organs, such as the lung, liver, and kidney; the lung is the most frequently affected. The aim of our study was to investigate the effects of dexmedetomidine on I/R damage in lung tissue and on the oxidant/anti-oxidant system in diabetic rats. Material and methods Diabetes was induced with streptozotocin (55 mg/kg) in 18 Wistar Albino rats, which were then randomly divided into three groups (diabetes control (DC), diabetes plus ischaemia-reperfusion (DIR), and diabetes plus dexmedetomidine-ischaemia/reperfusion (DIRD)) after the effects of diabetes were clearly evident. The rats underwent a left thoracotomy and then ischaemia was produced in the myocardium muscle by a left anterior descending artery ligation for 30 min in the DIR and DIRD groups. I/R was performed for 120 min. The DIRD group received a single intraperitoneal dose of dexmedetomidine (100 µg/kg); the DIR group received no dexmedetomidine. Group DC was evaluated as the diabetic control group and also included six rats (C group) in which diabetes was not induced. These mice underwent only left thoracotomy and were closed without undergoing myocardial ischaemia. Histopathological changes, activities of catalase (CAT) and glutathione-S-transferase anti-oxidant enzymes, and malondialdehyde (MDA) levels were evaluated in the lung tissues of all rats. Results Neutrophil infiltration/aggregation was higher in the DIR group than in the C, DC, and DIRD groups (p=0.001, p=0.013, and p=0.042, respectively). The lung injury score was significantly higher in the DIR group than in the C and DC groups (p<0.0001 and p=0.024, respectively). The levels of MDA were significantly higher in the DIR group than in the C and DIRD groups. CAT activity was significantly higher in the DIR group than in the DIRD and C groups. Conclusion Our results confirm that dexmedetomidine has protective effects against the lung damage resulting from I/R in diabetic rats. Future studies conducted to evaluate the effects of the use of dexmedetomidine on damage to various organs following different I/R durations may help understanding possible protective effects of dexmedetomidine and underlying mechanisms in tissue damage related to I/R injury.

The effect of levosimendan on lung damage after myocardial ischemia reperfusion in rats in which experimental diabetes was induced

BACKGROUND It is known that diabetic complications and lipid peroxidation are closely associated. During ischemia and reperfusion (IR), injury may occur in distant organs, as well as in tissues next to the region exposed to the ischemia, and the lungs can be one of the most affected of these organs. Therefore, this study investigated the effects of levosimendan on lung tissue and the oxidant-antioxidant system in diabetic rats. MATERIALS AND METHODS The study was conducted in 24 Wistar albino rats that were separated into four groups (C, control; DC, diabetic control; DIR, diabetic IR; and DIRL, diabetic IR levosimendan). Diabetes was induced in 18 rats using streptozotocin (55 mg/kg), and the animals were randomly separated into three groups after the effects of the diabetes became apparent. After a left thoracotomy, ischemia was performed on the myocardial muscle with the left main coronary artery (LAD) for 30 min in the DIR and DIRL groups. After ischemia, the LAD ligation was removed, and reperfusion was applied for 120 min. Single-dose intraperitoneal 12 μg/kg levosimendan was administered to group DIRL before the ischemia. Group DC was evaluated as the diabetic control group, and six rats were considered to be the control group (group C), in which thoracotomy was performed and then closed with no induction of myocardial ischemia. We measured the levels of malondialdehyde, as a lipid peroxidation end product, as well as catalase and glutathione S-transferase activities, as antioxidant enzymes in the lung tissue. Tissue samples were also examined histopathologically. RESULTS Neutrophil infiltration or aggregation in lung tissue was significantly higher in the DIR group compared with the C, DC, and DIRL groups (P = 0.003, P = 0.026, and P = 0.026, respectively). Alveolar wall thickening in lung tissue was significantly higher in the DIR group compared with the C, DC, and DIRL groups (P = 0.002, P = 0.002, and P = 0.006, respectively). In addition, the lung tissue damage score was significantly higher in the DIR group compared with the C, DC, and DIRL groups (P = 0.001, P = 0.004, and P = 0.007, respectively). Finally, catalase and glutathione S-transferase activity levels were significantly higher in the DIR group compared with those observed in the C, DC, and DIRL groups. CONCLUSIONS Although diabetes increases lipid peroxidation, it suppresses antioxidant activity. Our results showed that levosimendan had a protective effect against lung damage secondary to IR in the rats with induced diabetes. We recommend that experimental and clinical studies be conducted to examine the effects of levosimendan at different doses and different IR durations on various organs for clinical use.

The effect of levosimendan on myocardial ischemia–reperfusion injury in streptozotocin-induced diabetic rats

Objective Ischemia/reperfusion (I/R) injury is an important cause of myocardial damage by means of oxidative, inflammatory, and apoptotic mechanisms. The aim of the present study was to examine the potential cardio protective effects of levosimendan in a diabetic rat model of myocardial I/R injury. Methods A total of 18 streptozotocin-induced diabetic Wistar Albino rats (55 mg/kg) were randomly divided into three equal groups as follows: the diabetic I/R group (DIR) in which myocardial I/R was induced following left thoracotomy, by ligating the left anterior descending coronary artery for 60 min, followed by 2 h of reperfusion; the diabetic I/R levosimendan group (DIRL), which underwent I/R by the same method while taking levosimendan intraperitoneal 12 µg kg−1; and the diabetic control group (DC) which underwent sham operations without tightening of the coronary sutures. As a control group (C), six healthy age-matched Wistar Albino rats underwent sham operations similar to the DC group. Two hours after the operation, the rats were sacrificed and the myocardial tissue samples were examined by light microscopy for evidence of myonecrosis and inflammatory cell infiltration. Results Myonecrosis findings were significantly different among groups (p=0.008). Myonecrosis was more pronounced in the DIR group compared with the C, DC, and DIRL groups (p=0.001, p=0.007 and p=0.037, respectively). Similarly, the degree of inflammatory cell infiltration showed significant difference among groups (p<0.0001). Compared with C, DC, and DIRL groups, the inflammatory cell infiltration was significantly higher among the DIR group (p<0.0001, p<0.0001, and p=0.020, respectively). Also, myocardial tissue edema was significantly different among groups (p=0.006). The light microscopic myocardial tissue edema levels were significantly higher in the DIR group than the C, DC, and DIRL groups (p=0.001, p=0.037, and p=0.014, respectively). Conclusion Taken together, our data indicate that levosimendan may be helpful in reducing myocardial necrosis, myocardial inflammation, and myocardial tissue edema resulting from ischemia–reperfusion injury.

Assessment of the effects of levosimendan and thymoquinone on lung injury after myocardial ischemia reperfusion in rats

Aim The aim of this study was to investigate the effects of levosimendan and thymoquinone (TQ) on lung injury after myocardial ischemia/reperfusion (I/R). Materials and methods Twenty-four Wistar albino rats were included in the study. The animals were randomly assigned to 1 of 4 experimental groups. In Group C (control group), left anterior descending artery was not occluded or reperfused. Myocardial I/R was induced by ligation of the left anterior descending artery for 30 min, followed by 2 h of reperfusion in the I/R, I/R-levosimendan (24 µg/kg) (IRL) group, and I/R-thymoquinone (0.2 mL/kg) (IRTQ) group. Tissue samples taken from the lungs of rats were histochemically stained with H&E and immunohistochemically stained with p53, Bcl 2, Bax, and caspase 3 primer antibodies. Results Increased expression of p53 and Bax was observed (4+), especially in the I/R group. In IRTQ and IRL groups, expression was also observed at various locations (2+, 3+). H&E staining revealed that that the lungs were severely damaged and the walls of the alveoli were too thick, the number of areas examined was increased during the evaluation. Caspase 3 expression was observed to be at an (1+, 2+) intensity that was usually weak and diffuse in multiple areas. Bcl 2 was not found to be expressed in any of the tissues. H&E staining revealed that that the lungs were severely damaged in the I/R group, with the walls of the channels and alveoli thickened and edematous, and also an intense inflammatory cell migration was observed. Immunohistochemical staining was more prominent in inflammatory areas and structures around the terminal bronchioles. Conclusion The findings in our study have shown that administration of levosimendan and TQ during I/R increases expression of caspase 3, p53, and Bax in lung tissue and has a protective effect on lung as distant organ. We suggest that findings of this study be elucidated with further large-scale clinical studies.

Effects of hydroxyethyl starch 130/0.4 on the kidney tissue of rats with ureteral obstruction

Objective This study was conducted since the effects of colloid solutions on the renal system remain controversial and need to be adequately studied in animals. We aimed to evaluate the effects of hydroxyethyl starch (Voluven) on the kidney tissue of rats with late renal failure due to ureteral obstruction. Materials and methods Rats were divided into four groups: Group C, control; Group HES, hydroxyethyl starch solution (HES) 130/0.4 (Voluven®); Group UUO, unilateral ureteral obstruction (UUO); and Group UUO-HES, UUO-HES 130/0.4 (Voluven®). In the groups with ureteral obstruction, the distal part of the right ureter was accessed and sutured through a lower abdominal incision under ketamine anesthesia. Any signs of late-stage renal failure were evaluated after three weeks. Rats in the HES group and the renal failure-HES group were administered with HES 130/0.4 as a single intravenous dose of 20 mL/kg. After a follow-up of 24 hours, intra-abdominal blood sample was collected, and the rats were sacrificed. Biochemical and histopathological parameters were then evaluated. Results Ureteral obstruction significantly increased urea and creatinine levels. In addition, when the UUO-HES and HES groups were compared, the administration of HES increased urea and creatinine levels in the UUO-HES group. Nitric oxide enzyme activity and malondialdehyde levels have significantly increased in the UUO groups. In addition, HES significantly increased nitric oxide activity and malondialdehyde levels in the UUO-HES group, in comparison with the HES group. The activity of caspases 3 and 8 was significantly increased in the UUO groups. In addition, HES significantly increased the activity of caspases 3 and 8 in the UUO-HES group, in comparison with the HES group. Light microscopy revealed significant changes in the UUO groups, especially in the obstructed kidneys. Conclusion If indicated, HES should be used with caution in cases of UUO, but not in the cases of bilateral ureteral obstruction. Other aspects of these findings, including the clinical significance and practical applications, merit further experimental and clinical investigation.

Neutrophil lymphocyte ratio predicts postoperative pain after orthognathic surgery

Background and Aim: Postoperative pain is well known and usually disturbing complication of surgery. Inflammation plays an important role in the development and progression of postoperative pain. We aimed to investigate possible relationship between preoperatively measured neutrophil-lymphocyte ratio (NLR) – as an inflammation marker – and postoperative analgesic demand in patients underwent orthognathic surgery. Materials and Methods: We retrospectively investigated medical and anesthesia records of 177 patients underwent orthognathic surgery. Demographical data, preoperative NLR, type of surgery, modified Mallampati score, difficulty degree of intubation, duration of surgery, and postoperative analgesic (tenoxicam – as the first drug of choice, paracetamol, tramadol, or pethidine) usage were recorded. A cutoff value of NLR ≥2 was determined for inflammation threshold. Two groups (Group 1 NLR ≥2, Group 2 NLR <2) were compared for analgesic doses, numbers of patients needed analgesic treatment, and other parameters. Results: Mean administered tenoxicam dose was significantly higher in Group 1 than in Group 2 (P < 0.0001). Further, ratio of patients treated with tenoxicam in Group 1 was significantly higher than that in Group 2 (χ2 = 4.779, P = 0.029). Conclusions: Preoperatively measured NLR may help to predict postoperative analgesic demand in patients undergoing orthognathic surgery, and thus sufficient postoperative pain control can be achieved with various preventive treatments taken at the perioperative period such as preemptive analgesia, local anesthetic administration at the end of surgery, or early administration of analgesics.

Is age a determinant for nausea and vomiting in disabled patients after dental treatment under sedation

Background and Aim: Postoperative nausea and vomiting (PONV) is one of most frequently encountered problems after dental treatment of mentally and/or motor disabled patients under sedation or general anesthesia. In this study, we aimed to investigate whether PONV incidence in disabled patients differs between adults (≥18 years) and children/teenage (<18 years). Also investigating complication rates related with anesthesia protocols were additional objectives of the study. Materials and Methods: We retrospectively evaluated anesthesia reports of 664 cases undergone different dental treatment procedures under deep sedation with various anesthetic agents. Two study groups (Group 1 consisted from patients with special needs <18 years, while Group 2 consisted from patients ≥18 years) were created. PONV incidence and other complications recorded. Results: There was no statistical difference between groups in terms of used anesthetic agent except midazolam (P < 0.017), while higher female/male ratio and longer duration of anesthesia was recorded in Group 2 (P = 0.043 and P = 0.046, respectively). We found significantly higher PONV rates in disabled patients under 18 years (P = 0.006). Hypoxia (peripheral oxygen saturation (SpO2) <90%) and bradycardia (heart rate <50/minute) were observed in only two patients. Conclusion: PONV is more common in disabled patients younger than 18 years and dental treatment procedures under deep sedation can be provided with acceptable complication rates in patients with special needs.

A retrospective analysis of blood gases with two different insulin infusion protocols in patients undergoing cardiovascular surgery

AIM Intraoperative blood glucose concentration is known to be an independent risk factor for morbidity and mortality in patients undergoing cardiovascular surgery. Arterial blood gas analysis is an important investigation to monitor the acid-base balance and gas exchange in these patients. Hyperglycemia leads to a series of metabolic changes which affect acid-base balance and serum electrolytes. In this study, we aimed to look into the effect of glycemic control on arterial blood gas parameters, serum electrolytes, and hemoglobin (Hb). MATERIALS AND METHODS We collected data from diabetic patients who underwent cardiovascular surgery between 2010 and 2014. The patients were divided into two groups according to the insulin infusion protocols applied such as with conventional (180-250 mg/dl) (n = 17) (Group 1) and tighter glycemic targets (121-180 mg/dl) (n = 51) (Group 2). We retrospectively analyzed arterial blood gas results taken at different perioperative time points from these patients. RESULTS We found that pH HCO3and base excess, serum sodium, potassium, calcium, and Hb were similar in both groups. CONCLUSION Our study showed that a tighter intraoperative glycemic control does not affect arterial blood gas parameters, serum electrolytes, or Hb when compared to the conventional glycemic control.

Our Sedation Experience on Mentally Retarded Patients

Aim: The majority of dental treatments can be performed under local anesthesia. However, sedation or general anesthesia are often required for men tally retarded patients presenting a lack of cooperation. The aim of this study was to retrospectively evaluate the outcomes of mentally retarded patients treated under sedation. Material and Method: The records of the 214 mentally retarded patients that were treated under sedation between 2010-2012 were retrospectively evaluated. The retrospective data included demographic variables, duriation of anesthesia, anti-epileptic drugs used, level of sedation, anesthetic agents, the type of dental treatment and adverse events during and after sedation. Results: In this study the mean age of patients was 22,49±9,54. The female/male ratio was 109/105. The number of ASA I, II, III patients were 43, 157 and 14 respectively. 16.8% of the patiens (n=36) was on one anti-epileptic drug regimen, while 29.9% of the patiens (n=54) was on more than one anti-epileptic drug regimen. The sedation levels were determined as minimal sedation (6.5%, n=14), moderate sedation (35%, n=75) and deep sedation (58.4%, n=125) respectively. The midazolam-ketamine combination was the most preferred anesthetic regimen (41.1%, n=88). Single dental extraction was the most performed dental treatment (58.4%, n=125). Postoperative nausea and vomiting was encountered in 3.7% of patients (n=8). Respiratuar depression occurred in 2 patients. Two patients developed bronchospasm, while one patient developed postoperative agitation, deep bradycardia and allergic reaction respectively. Discussion: We are of the opinion that sedation can be performed safely by choosing the appropriate drug and method without depressing respiration and reflexes.