Assesment of correlation between bispectral index and four common sedation scales used in mechanically ventilated patients in ICU.

PURPOSE: The aim of this study was to compare the correlation between bispectral index (BIS) monitor and four commonly used subjective clinical scales (Ramsay Sedation Scale (RSS), Richmond Agitation Sedation Scale (RASS), Sedation Agitation Scale, Adaptation to Intensive Care Environment scale) in mechanically ventilated patients in intensive care unit (ICU). In addition, comparison of responsiveness of the clinical scales in respect to BIS changes is another goal of this study. MATERIALS AND METHODS: Mechanically ventilated thirty patients who required sedation for any reason were enrolled to study. Patients who needed neuromuscular blockade, patients with known hearing and visual problems, neurological diseases, anoxic encephalopathy, mental retardation and who developed hemodynamic instability (mean arterial pressure below 60 mmHg) and hypoxemia (sPO2 below 90%) during follow-up were excluded. Starting before the initiation of sedation, first BIS scores then clinical sedation scales were evaluated. This procedure is repeated every 2 hours for 24 hours. RESULTS: All of the four clinical scales were significantly correlated with BIS. BIS and clinical scale values, except Adaptation to Intensive Care Environment scale, showed significant changes compared to baseline after the initiation of sedation. Ramsay and Richmond scales showed the highest correlation with BIS (respectively, r = 0.758, r = 0.750). Adaptation to Intensive Care Environment revealed the lowest correlation (r = 0.565). CONCLUSIONS: All of the scales were significantly correlated with BIS. RSS and RASS showed higher correlation than other scales. As a conclusion: RSS and RASS can be used for monitoring the depth of sedation in mechanically ventilated patients in ICU.

Determination of DNA damage after exposure to inhalation anesthetics in human peripheral lymphocytes and sperm cells in vitro by comet assay.

In this study, genotoxic activities of four halogenated anesthetics (halothane, isoflurane, sevoflurane and desflurane) were investigated in human peripheral blood lymphocytes (PBLs) and sperm cells in vitro by alkaline comet assay. For this purpose, sperm or lymphocyte suspension was exposed to different concentrations (0.1 mM, 1 mM, 10 mM and 100 mM) of anesthetic agents and 1% dimethyl sulfoxide (DMSO) or phosphate-buffered saline (PBS) as controls. The DNA strand breaks as well as alkali-labile sites were measured as percentage tail intensity with comet assay. The results of this study demonstrate that all analyzed drugs were capable of inducing DNA damage on PBLs in a dose-dependent manner in vitro. However, the results in sperm cells were slightly different since we did not observe any genotoxic effect for desflurane in any of the exposure doses, and the genotoxic effect of halothane was not dose dependent. This experimental study points out to the presence of DNA damage after exposure to halogenated anesthetics in both PBLs and sperm cells, although this effect seems to be higher in PBLs.

Epidural volume expansion: is there a ceiling effect?

AIM: The optimal volume of epidural saline administration on spinal anesthesia is not clear. The aim of this study was therefore to evaluate the block characteristics of 5, 10, 15, and 20 mL epidural saline after spinal anesthesia. METHODS: This prospective, randomized double-blind study was conducted in the operation room setting of a university hospital. Seventy-five healthy adult patients electively undergoing limb surgery under regional anesthesia were investigated. Spinal anesthesia was performed, and plain bupivacaine (10 mg) was administered within one minute using combined spinal and epidural anesthesia. Epidural catheters were introduced, and patients were allocated to one of five groups to receive 0, 5, 10, 15 or 20 mL saline through the catheter (N=15 in each group). The patient was assessed every minute for motor and sensory block levels until a maximum level was reached. In addition, the patient was assessed thereafter in five-minute intervals using Bromage's scale for motor block and pinprick/cold sensation for sensory block. RESULTS: The maximum level of spinal analgesia was significantly lower in the control group compared to the saline treatment groups, but there was no significant difference between the epidural saline groups. The periods for motor block resolution were the same. The duration of analgesia was significantly longer in patients receiving 15 mL saline compared to other groups. The time to regression to the L1 level was significantly longer with 15- and 20-mL treatment groups compared to the 5- and 10-mL groups. CONCLUSION: The present results indicate that a ceiling effect was observed on the duration of spinal analgesia using plain bupivacaine with epidural saline loading (maximum--15 mL).

Oxidative DNA damage and total antioxidant status in rats during experimental gram-negative sepsis.

Sepsis and septic shock remains as leading cause of death in adult intensive care units. It is widely accepted that gram-negative bacteria and their endotoxins cause sepsis and septic shock, predominantly. Enhanced generation of reactive oxygen species may be responsible for tissue injury in septic shock and endotoxemia. The aim of this study was to assess oxidative DNA damage and the total antioxidant status (TAS) in peripheral lymphocytes of rats during different intraperitoneal gram-negative sepsis stages. Adult male Sprague-Dawley rats were divided randomly into four groups. Control group was intraperitoneally inoculated with 2 mL of pyrogene-free saline (Group I, n = 6), and the other rats received an intraperitoneal inoculum with 2 mL of saline containing 2 x 10(8) CFU of Escherichia coli. The animals were killed at time zero (Group I, n = 6), at 6th (Group II, n = 7), 12th (Group III, n = 7), and 24th (Group IV, n = 7) hour after the E. coli inoculation. Oxidative DNA damage in peripheral lymphocytes of rats was evaluated by modified comet assay (single-cell gel electrophoresis). Formamidopyrimidine DNA glycosylase (Fpg) and Endonuclease III (Endo III) were used to detect oxidized purines and pyrimidines, respectively. Total antioxidant quantification was carried out using ABTS+ (2,2'-Azino-di-[3 ethylbenzthiazoline sulphonate]) radical formation kinetics (Randox kit) in serum samples. Significant elevations of basal levels of strand breaks (SB) in Group IV were observed as compared with Group I, II, and III. There was a significant increase in Fpg sites in Group III as compared with Group I and II. However, there was no significant difference in terms of Endo III sites in any of the groups. Although the TAS was decreased with the stages of sepsis, this moderate decrease was significant in only Group IV as compared with Group I. There was no statistically significant correlation between DNA damage and TAS for any of the groups.

Association between GSTP1 gene polymorphism and serum alpha-GST concentrations undergoing sevoflurane anaesthesia.

BACKGROUND AND OBJECTIVES: The measurement of alpha-glutathione-S-transferase enzyme is one of the most sensitive indicators of hepatocellular function. Variation in the glutathione-S-transferase P1 gene clusters has been intensively investigated and polymorphism has been described. The aim of the study was to assess whether an association exists between glutathione-S-transferase P1 gene polymorphism and serum alpha-glutathione-S-transferase concentrations for the first postoperative day in patients who underwent anaesthesia with sevoflurane. METHODS: In all, 54 unrelated patients were enrolled in this study. Anaesthesia was induced with thiopental and fentanyl. Vecuronium was used for neuromuscular relaxation before endotracheal intubation. Anaesthesia was maintained with sevoflurane in a gas mixture containing 50% nitrous oxide in oxygen. Peripheral venous blood samples to determine serum alpha-glutathione-S-transferase concentrations were collected before induction (T1), at the end of anaesthesia (T2) and at 24-h postoperatively (T3). Enzyme-linked immunosorbent assay (ELISA) immunoassay was used to measure alpha-glutathione-S-transferase levels. Genomic DNA was isolated from serum samples using a genomic DNA purification kit. In order to detect the variants of glutathione-S-transferase P1, polymerase chain reaction-restriction fragment length polymorphism analysis was employed. RESULTS: Early postoperative serum alpha-glutathione-S-transferase levels for all patients were significantly increased when compared with preanaesthetic and 24-h postoperatively (P 0.05). CONCLUSIONS: Although alpha-glutathione-S-transferase levels were elevated in all patients after sevoflurane anaesthesia, levels remained high at 24 h in patients with glutathione-S-transferase P1 Ile105Val genotypes compared to controls.

An intraoperative unexpected respiratory problem in a patient with Apert syndrome.

We present a case of a 5-year-old child who underwent four operations (three for syndactyly of the hands and one for craniofacial corrections). At the third hour of his craniofacial operation, his EtCO2 started to increase and airway resistance was encountered during manual ventilation. The position of the head and neck was checked. An increase in secretion with oral and endotracheal aspiration and a decrease in saturation were observed. When breath sounds disappeared, the patient was reintubated orally. The nasal tube was obstructed with a mucolytic plug. There was no problem during the other operations. This case is presented since anaesthesiologists should be aware of the high incidence of respiratory complications in Apert syndrome.