The effects of nitrous oxide on vitamin B12 and homocysteine levels in methyltetrahydrofolate reductase gene mutation.

BACKGROUND: We aimed to investigate the effects of nitrous oxide on plasma total homocysteine and vitamin B12 levels in patients with or without methyltetrahydrofolate reductase (MTHRF) gene mutation. METHODS: After obtaining the ethics committee approval and written informed consents of patients, 93 patients between 18-70 years of age scheduled for surgery anticipated to last 1-4 hours were enrolled in the study. Patients with contraindications for nitrous oxide use were excluded. Preoperatively, blood samples were obtained from all patients for the determination of MTHFR gene mutation. Anesthesia induction was achieved with 3 mg.kg-1 of propofol and 1 µg.kg-1 of fentanyl. Anesthesia maintenance was performed with sevoflurane and with a carrier gas composed of 40 % O2 and 60 % N2O. Venous blood samples were obtained after venous canulation, and 24 hours after extubation for the analysis of plasma total homocysteine, vitamin B12 levels. RESULTS: Eighty-one patients were included in the study. Postoperative vitamin B12 levels were found to be significantly lower when compared with their preoperative levels (p<0.05). It was found that MTHRF gene polymorphism had no significant effect on postoperative plasma total homocysteine and serum vitamin B12 levels (p>0.05). Postoperative plasma total homocysteine levels were found to be significantly different between patients with operation times under and over 3 hours (p=0.028). CONCLUSIONS: We conclude that MTHRF gene polymorphism had no significant effects on postoperative plasma total homocysteine levels. However, we found that homocysteine levels might rise in patients who received general anesthesia with nitrous oxide for longer than 3 hours (Tab. 7, Ref. 26).

The analgesic effect of dexketoprofen when added to lidocaine for intravenous regional anaesthesia: a prospective, randomized, placebo-controlled study.

This prospective, randomized, placebo-controlled study evaluated the effects of dexketoprofen as an adjunct to lidocaine in intravenous regional anaesthesia (IVRA) or as a supplemental intravenous (i.v.) analgesic. Patients scheduled for elective hand or forearm soft-tissue surgery were randomly divided into three groups. All 45 patients received 0.5% lidocaine as IVRA. Dexketoprofen was given either i.v. or added into the IVRA solution and the control group received an equal volume of saline both i.v. and as part of the IVRA. The times of sensory and motor block onset, recovery time and postoperative analgesic consumption were recorded. Compared with controls, the addition of dexketoprofen to the IVRA solution resulted in more rapid onset of sensory and motor block, longer recovery time, decreased intra- and postoperative pain scores and decreased paracetamol use. It is concluded that coadministration of dexketoprofen with lidocaine in IVRA improves anaesthetic block and decreases postoperative analgesic requirements.

An evaluation of P wave dispersion, QT, corrected QT and corrected QT dispersion intervals on the electrocardiograms of malnourished adults.

The aim of our study was to investigate P wave dispersion (Pwd), QT corrected QT (QTc), QT dispersion (QTd) and corrected QT dispersion (QTcd) intervals in subjects with malnutrition diagnosed in the pre-anaesthetic assessment, compared to those without malnutrition. A total of 76 adult patients were included. Main diagnoses, anthropometric measurement, body mass index, electrocardiogram and serum sodium, potassium, chloride, magnesium and calcium levels were recorded for all patients. Pwd, QT and QTd intervals were measured on all electrocardiogram records and QTc and QTcd intervals determined with the Bazett formula. Protein-energy malnutrition was diagnosed with the nutritional risk index. No statistically significant difference was found between the age, gender and malignant cancer diagnosis rates between patients with malnutrition (group M) and those not suffering from malnutrition (group N) (P > 0.05). Serum albumin, total protein, potassium, calcium, magnesium and chloride values of group M were found to be significantly lower than group N (P < 0.05). In group M, Pwd, QT, QTc, QTd and QTcd intervals were significantly longer than in group N (P < 0.001). Patients diagnosed with malnutrition during pre-anaesthetic assessment had significantly longer Pwd, QTc and QTcd interval durations than the control group. We attribute such extended Pwd, QTc and QTcd durations in these patients to malnutrition and malnutrition-related electrolyte imbalance.