Analgesic Efficacy of Erector Spinae Plane Block in Pediatric Abdominal Surgery: Guidance with Conventional Method and NOL: Case Series.

Background: Erector spinae plane (ESP) block is a regional anesthesia technique that blocks both somatic and visceral nerve fibers. Despite its high analgesic potential, its mechanism of action is not yet fully understood. The ultrasound-guided ESP block, which can be easily performed, makes important contributions to the control of intraoperative pain in pediatric patients undergoing abdominal surgery. The follow-up of pain in the intraoperative period is usually done by evaluating the changes in hemodynamic parameters. Due to physiological differences in pediatric patients, it is more difficult to do this with only hemodynamic changes than in adult patients. Aim: The NOL® (Nociception Level) monitor calculates the nociception/pain score by evaluating many parameters through a proprietary algorithm. Our primary aim was to demonstrate the effectiveness of ESP block with an advanced pain monitor in this patient group; our secondary aim was to investigate the necessity of pain monitors in the pediatric patient group. Methods: In this case series, we applied intraoperative NOL® monitoring in addition to standard monitoring (ECG, SpO2, heart rate, EtCO2) in pediatric patients (16 cases) who were scheduled for abdominal surgery and underwent ESP block. Results: Considering the hemodynamic data, NOL values, postoperative pain scores, side effects, and complications, it was concluded that ESP block can be used safely in this patient group. Although the hemodynamic data and the NOL® index were compatible with each other after a nociceptive stimulus, the NOL index was less affected by other variables and gave the clinician clearer information about pain.

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.

Are there any effects of Sevoflurane and Desflurane anaesthesia on blood glucose levels in acute hyperglycemic diabetic rats?

AIM: The aim of this study was to investigate blood glucose level of desflurane and sevoflurane on blood glucose in diabetic rats undergoing acute hyperglycemia. MATERIALS AND METHODS: In this study, 30 male Wistar albino rats were included. Diabetes was induced by a single IP injection of streptozotocin. After the effects of chronic diabetes encountered, diabetic rats were randomly assigned into diabetic control (group DC), diabetic hyperglycemia group (group DH), diabetic hyperglycemia group with desflurane (group DH-D), and diabetic hyperglycemia group with sevoflurane (group DH-S) groups. The normoglycemic groups received an IP injection of the same amount of saline. Hyperglycemic diabetic rats were anaesthetized by desflurane 6 % or sevoflurane 2 % at a dose, by which minimal alveolar concentration (MAC) for rats would be one. The drugs were given for 4 hours within 100 % oxygen at a rate of 6 L.min-1. One hour after cessation of inhalation anesthesia, blood glucose levels were determined at 1st, 4th and 24th hours. 24 hours after the anaesthesia. RESULTS: Serum glucose was detected to be significantly lower in Group C, when compared to Groups DC, DH, DH-D and DH-S (p = 0.002, p = 0.001, p = 0.002, p = 0.003, respectively). Blood glucose levels in the diabetic groups were similar at the end of 6 weeks period, after hyperglycemia and anaesthesia induction. CONCLUSION: We found out that sevoflurane and desflurane administrations in hyperglycemic rats were both related with insignificant blood glucose level increase at early post anaesthesia period and at post anaesthesia 24th hours. We still think that patients undergoing anaesthesia protocols with acute hyperglycemia need relatively longer follow up periods (Tab. 1, Ref. 28).

Oxidative stress and antioxidant activity of female rat liver tissue after sevoflurane anaesthesia: young versus old.

AIM: The aim of our study was to assess the evidence of oxidative stress in the rat liver tissue by studying enzymes, such as nitric oxide synthase (NOS), superoxide dismutase (SOD), glutathione-S transferase (GST) activity, and thiobarbutiric acid-reactive substances (TBARS) levels in young versus old female rats after sevoflurane anaesthesia. MATERIAL AND METHOD: The study involved 28 female Wistar Albino rats. The rats were divided into the two groups [(Group I, n=14): Young sevoflurane group (Group I-YS, n=7); Young control group (Group I-YC, n=7)], [(Group II, n=14): Old sevoflurane group (Group II-OS, n=7); Old control group (Group II-OC, n=7)]. Sevoflurane was administered at 2 % volume inspiratory concentration, 6 L.min-1 in 100 % O2 for 2 hours. The control groups were not subjected to any procedures. Accordingly, GST, SOD, and NOS enzyme activity and TBARS level, were studied in the liver tissue samples of the rats to determine the presence of oxidative stress (OS) and antioxidant activity. RESULTS: Following administration of sevoflurane anaesthesia; GST, SOD enzyme activity and TBARS level was significantly higher in the Group I-YS than in the Group I-YC and in the Group II-OS than in the Group II-OC. There was no difference between the groups when the mean NOS levels were compared. CONCLUSION: Although the results of our study are similar to the previous indicating that sevoflurane has the capacity to induce the oxidative stress; a new data has been recorded that sevoflurane has a similar effect on the OS level in aged and young female rat (Tab. 1, Fig. 4, Ref. 48).

Does vitamin C prevent the effects of high dose dexmedetomidine on rat erythrocyte deformability?

PURPOSE: Dexmedetomidine is an anesthetic agent frequently used for sedation at the intensive care units and during general anesthesia. The purpose of our study was to investigate whether vitamin C prevents the effect of high dose dexmedetomidine on erythrocyte deformability in rats. METHODS: The study was performed on 21 male rats, with 7 rats in each study groups and the control group. The rats in the study groups were treated with intraperitoneal dexmedetomidine (10 µg/kg) and intraperitoneal dexmedetomidine plus Vitamin C (ascorbic acid) (100 mg/kg ascorbic acid administered 1 hour before administration of 10 µg/kg dexmedetomidine), respectively. Intraperitoneal physiological saline was administered in the control group. Erythrocyte packs were prepared using heparinized total blood samples. Deformability measurements were done by erythrocyte suspensions in phosphate buffered saline (PBS) buffer. A constant flow filtrometer system was used to measure erythrocyte deformability and the relative resistance was calculated. RESULTS: Erythrocyte deformability was significantly higher in dexmedetomidine group than in control and vitamin C plus dexmedetomidine groups (p=0.003, p=0.013, respectively). Erythrocyte deformability indexes were found similar in the control group and in the vitamin C plus dexmedetomidine group (p=0.383). CONCLUSIONS: High dose dexmedetomidine may cause functional deterioration in blood flow and tissue perfusion with negative effects in erythrocyte deformability. Vitamin C supplementation seems to reverse those negative effects and variations in erythrocyte deformability. However, our preliminary results should be confirmed in wider serious of experimental and clinical trials (Fig. 1, Ref. 27).

Comparison of effects of anaesthesia with desflurane and enflurane on liver function.

INTRODUCTION: Although most general anaesthesia procedures are performed without any complications, volatile agents may have adverse effects on various living systems. This study aimed to compare the effects of desflurane and enflurane on liver function. METHODS: 40 patients, who were in the ASA I-III risk groups and were planned to undergo head and neck surgery of at least three hours' duration, were randomly divided into two groups: the desflurane (Group D) and enflurane groups (Group E). Venous blood samples (5 ml) of the patients were obtained before anaesthesia induction, in the postoperative first hour and on the first and seventh days. The samples were centrifuged and then stored at -80 degrees Celsius until the determination of glutathione S-transferase (GST) levels. For maintenance of anaesthesia in Group D, desflurane (6 percent) was used, while in Group E, enflurane (1.2 percent) was used. RESULTS: GST levels were significantly higher in Group E in the postoperative first hour (p-value is 0.002), and on the first day (p-value is 0.025) and seventh day (p-value is 0.035), although there were no differences preoperatively (p-value is more than 0.05). When postoperative levels were compared with preoperative levels, the postoperative GST levels of Group E were significantly higher (first hour [p-value is 0.008], first day [p-value is 0.010], seventh day [p-value is 0.038]). CONCLUSION: Subclinical hepatic injury after anaesthesia continues to be an issue of interest, particularly with the development of new, more sensitive methods of measuring GST levels. The increase in GST concentration after anaesthesia is thought to be a result of reduced hepatic blood flow. This study has shown that desflurane has fewer effects than enflurane on liver function tests in lengthy operations of up to 330 minutes.

Total intravenous anaesthesia and the use of an intubating laryngeal mask in a patient with osteogenesis imperfecta.

Osteogenesis imperfecta is a genetically determined rare disease of the connective tissue, associated with abnormalities of type 1 collagen. The primary bone lesion is the lack of normal ossification of the endochondrial bone. Patients with osteogenesis imperfecta present several problems for anaesthetists. They have a tendency to develop malignant or non-malignant hyperthermia. During laryngoscopy and tracheal intubation, the mandible, teeth and cervical spine may be fractured or injured, and mucosal bruising or bleeding may occur. Renal or ureteral stones are common. The main problems are thus with airway control and intubation, and the risk of anaesthetic agents triggering malignant hyperthermia. We describe the successful anaesthetic management of a patient with osteogenesis imperfecta, undergoing nephrolithotomy and ureterolithotomy with total intravenous anaesthesia including propofol, remifentanil and cisatracurium, using an intubating laryngeal mask.

Impaired antioxidant defence in guinea pig heart tissues treated with halothane.

PURPOSE: To investigate the effects of halothane and halothane plus vitamin E treatment on myocardial free radical metabolism in guinea pigs. METHODS: Four groups of seven animals were studied: control, halothane, halothane plus vitamin E and vitamin E groups. In the halothane group, halothane 1.5% in oxygen was given for 90 min over three days. In the halothane plus vitamin E group, 300 mg.kg-1.day-1 vitamin E im was started three days before the first halothane treatment and continued for three days. Following sacrifice, the hearts were assayed for superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and malondialdehyde (MDA) level was determined. Electron spin resonance (ESR) analysis and electron microscopy (EM) were also performed. RESULTS: In the halothane group, SOD activities and MDA concentrations were increased compared with control and GSH-Px and CAT activities were decreased. In the halothane plus vitamin E group, there were no differences in enzyme activity compared with halothane alone but the MDA level was decreased. In the vitamin E group, enzyme activities were increased compared with control. Mainly the CF3CHCl radical was identified by ESR analysis in heart tissues exposed to halothane and the concentration of this radical was reduced by vitamin E. Electron microscopy showed cytoplasmic vacuolisation and dilation in sarcoplasmic reticulum in the heart tissues exposed to halothane: both were prevented by vitamin E. CONCLUSION: Although halothane causes impairment in enzymatic antioxidant defence potential, due to lowered GSH-Px and CAT activity, and accelerates peroxidative reactions in the tissues affected, no subcellular damage occurred. Vitamin E may protect tissues against free radical attack by scavenging toxic free radicals formed in heart tissue during halothane anaesthesia.

Halothane hepatotoxicity and hepatic free radical metabolism in guinea pigs; the effects of vitamin E.

PURPOSE: The aim of this study was to investigate the relation between halothane hepatotoxicity and hepatic free radical metabolism and to establish a possible protective role of vitamin E against halothane hepatotoxicity. METHODS: Twenty-eight guinea pigs were used in the experiments. Halothane (1.5% v/v) in oxygen (100%) was given to the animals for 90 min over three days. Livers from animals were then taken and prepared for the assays. In the enzymatic study, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities were measured. As a peroxidation index, the malondialdehyde (MDA) concentration was determined. Also, electron spin resonance (ESR) analysis and electron microscopy (EM) were performed. RESULTS: Superoxide dismutase (1168.3 +/- 78.2 U.mg-1) and glutathione peroxidase (14.9 +/- 6.2 mIU.mg-1) activities were decreased, but catalase activity (1260.0 +/- 250.6 IU.mg-1) and malondialdehyde concentration (11.5 +/- 1.8 ppb) were increased in liver tissues exposed to halothane compared with control values (1382.2 +/- 91.8 U.mg-1 for SOD, 27.8 +/- 5.2 mIU.mg-1 for GSH-Px, 840.2 +/- 252.4 IU.mg-1 for CAT and 10.0 +/- 1.0 ppb for MDA). Electron spin resonance analysis revealed a peak of CF3CHCl. radical in the exposed tissue. Electron microscopy indicated ultrastructural changes in the hepatic cells of both halothane groups with and without vitamin E treatment. CONCLUSION: Halothane causes impairment in the hepatic antioxidant defense system and accelerates peroxidation reactions. As a result, some ultrastructural changes in hepatic tissues occur due to halothane treatment. Although vitamin E prevents peroxidative damage, it does not ameliorate ultrastructural changes caused by halothane treatment. This shows that halothane toxicity results not only from impaired hepatic antioxidant defense system but also from other, unknown causes.