The Comparison of the Effects of Epidural Bupivacaine and Levobupivacaine on the Autonomic Nervous System and Cardiac Arrhythmia Parameters in Inguinal Hernia Surgeries.

OBJECTIVE: The aim of this study is to investigate the effects of bupivacaine and levobupivacaine, used to create epidural anaesthesia in inguinal hernia operations, on heart rate variability and cardiac arrhythmia parameters. METHODS: Sixty male patients of the American Society of Anesthesiology (ASA) I-II group, scheduled to be operated on for inguinal hernia surgery with epidural anaesthesia, were randomly divided into two groups. The patients, with a 12-channel Holter recorder (Rozinn RZ153+12-USA) attached 1 hour before the operation to record until the end of the surgery, were taken into the preparation room and anaesthetised. In group L (n=30), 17 mL of 0.5% levobupivacaine (Chirocain 0.5%-Abbot, El-verum, Norway) was given into the epidural space within 10 minutes, versus 17 mL of 0.5% bupivacaine in (Marcain 0.5%, Astra Zeneca, Istanbul, Turkey) group B (n=30). After 30 minutes, when there was enough block, the operation had been started. Holter recordings, starting 1 hour before the anaesthetic procedure and completed by the end of the operations, were transferred to the computer. The records were evaluated by the cardiologists. RESULTS: When analysing the frequency effect measurement results of the heart rate variability, it was seen that neither of the medications created any statistically significant change in or among the groups in total, very-low-frequency (VLF), low-frequency (LF), high-frequency (HF) and LF/HF ratio levels. Only normalised low-frequency band was significantly lower in Group L (p=0.013). CONCLUSION: In the volumes and concentrations that were used in our study, levobupivacaine and bupivacaine created sensory blockade at the same level on average and did not reduce heart rate variability at the levels of these blockages.

Left-molar approach for direct laryngoscopy: is it easy?

PURPOSE: For direct laryngoscopy, we compared midline and left-molar approaches with respect to ease of intubation, using a Macintosh blade. We investigated the relationship between failure of the left-molar approach and preoperative risk factors for difficult intubation. METHODS: With local ethics committee approval, 200 consecutive adult, nonpregnant patients were included in the study. The demographic data, body mass index, Mallampati modified score, interincisor gap, and mentohyoid and thyromental distances were measured preoperatively. First, the Macintosh blade was inserted using the midline approach, and then optimal external laryngeal manipulation (OELM) was applied. Second, the blade was inserted using the left-molar approach. The glottic views were assessed according to the Cormack-Lehane classification before and after OELM in both approaches. In cases where tracheal intubation failed with the left-molar approach, the midline approach was applied again and endotracheal intubation took place. RESULTS: The grade I glottic view obtained using the midline approach without OELM did not change in 94.3% of the patients with the left-molar approach without OELM; in addition, the grade II glottic view improved to grade I in 52.8% of the patients with the same technique (P < 0.001). Although the number of patients with a grade I or II glottic view in the left-molar approach was 197, only 37 patients could be intubated using the left-molar approach. In addition, 59.5% of them were intubated at the second attempt with the left-molar approach, while the incidence of a second attempt was 1.2% with the midline approach (P < 0.001). There was no correlation between the preoperative risk factors for difficult intubation and failure of the left-molar approach. CONCLUSION: Difficulty in the insertion of the endotracheal tube limits the efficacy of the left-molar approach. It is not possible to predict the failure of intubation with the left-molar approach by considering the preoperative risk factors.

Biological and chemical removal of Cr(VI) from waste water: cost and benefit analysis.

The objective of the present study is cost and benefit analysis of biological and chemical removal of hexavalent chromium [Cr(VI)] ions. Cost and benefit analysis were done with refer to two separate studies on removal of Cr(VI), one of heavy metals with a crucial role concerning increase in environmental pollution and disturbance of ecological balance, through biological adsorption and chemical ion-exchange. Methods of biological and chemical removal were compared with regard to their cost and percentage in chrome removal. According to the result of the comparison, cost per unit in chemical removal was calculated 0.24 euros and the ratio of chrome removal was 99.68%, whereas those of biological removal were 0.14 and 59.3% euros. Therefore, it was seen that cost per unit in chemical removal and chrome removal ratio were higher than those of biological removal method. In the current study where chrome removal is seen as immeasurable benefit in terms of human health and the environment, percentages of chrome removal were taken as measurable benefit and cost per unit of the chemicals as measurable cost.