Comparison of propofol-dexmedetomidine, tiopental-dexmedetomidine and etomidate-dexmedetomidine combinations' effects on the tracheal intubation conditions without using muscle relaxants.

BACKGROUND: In our study, we aimed to compare the endotracheal intubation conditions without muscle relaxants during induction with the combinations of dexmedotimidine-propofol, dexmedotimidine-thiopenthal and dexmedetomidine-etomidate. METHOD: Seventy-six patients, in ASA risk group I-II, between ages 20-60 years, with Mallampati Class 1 were included in the study. All patients were premedicated with midazolam. The patients were randomly divided into three groups as Group P (n=30, dexmedetomidine-propofol), Group T (n=30, dexmedetomidine-thiopenthal), Group E (n=16, dexmedetomidine-etomidate). All patients received dexmedetomidine 1 µg.kg-1 in 10 min. Then, the patients were administered 2.5 mg.kg-1 propofol for Group P, 5 mg.kg-1 thiopental for Group T and 0.3 mg.kg-1 etomidate for Group E during induction. Hemodynamic data of the patients were recorded before induction, after dexmedetomidine administration, immediately after intubation and 3, 5 and 10 minutes after intubation. RESULTS: There was no difference between the groups according to hemodynamic data. Sixteen patients in Group P and 10 patients in Group T had acceptable intubation conditions. Muscle relaxant was needed in 14, 20 and 16 patients in Groups P, T and E, respectively (p<0.05). CONCLUSION: In conclusion, we determined that best intubation conditions without muscle relaxants were achieved with propofol-dexmedetomidine combination. None of the patients receiving etomidate -dexmedetomidine combination could be intubated without muscle relaxants (Tab. 6, Ref. 29).

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.

Non-invasive mechanical ventilation with spinal anesthesia for cesarean delivery.

We present the successful use of perioperative non-invasive mechanical ventilation in a morbidly obese pregnant woman with bronchial asthma, severe preeclampsia and pulmonary edema undergoing an emergency cesarean delivery with spinal anesthesia. The combination of non-invasive mechanical ventilation with neuraxial anesthesia may be of value in selected parturients with acute or chronic respiratory insufficiency requiring surgery.

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.

Antimicrobial effects of two anaesthetic agents: dexmedetomidine and midazolam.

Some anaesthetic agents are known to inhibit microbial growth. The aim of this in vitro study was to investigate possible antimicrobial effects of two frequently used agents in intensive care units, dexmedetomidine and midazolam. Antimicrobial effect was tested on Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa by broth microdilution method. Midazolam showed inhibitor and bactericidal effect on S. aureus at concentrations 256 mmicrog x ml(-1) and 512/microg x ml(-1) respectively and on E. faecalis at concentrations 128 microg x ml(-1) and 256 microg x ml(-1). Dexmedetomidine demonstrated inhibitor effect on S. aureus, E. coli and P aeruginosa at concentrations 32 microg x ml(-1), 16 microg x ml(-1) and 16 microg x ml(-1) respectively. Midazolam had inhibitor and bactericidal effects on S. aureus and E. faecalis. Dexmedetomidine had only inhibitor effects on S. aureus, E. coli and P aeruginosa. Further studies are needed to determine the antimicrobial mechanisms and clinical applications.

Does dexmedetomidine reduce the injection pain due to propofol and rocuronium?

BACKGROUND AND OBJECTIVES: This prospective, double-blind, randomized, placebo-controlled study was designed to determine the efficacy of dexmedetomidine compared with lidocaine in reducing the pain of propofol and rocuronium injection pain. METHODS: One hundred and fifty patients, scheduled for elective surgery with general anaesthesia, were divided into five groups: saline (Group 1), dexmedetomidine 0.25 microg kg(-1) (Group 2), lidocaine 0.5 mg kg(-1) (Group 3), dexmedetomidine 0.25 microg kg(-1) plus lidocaine 0.25 mg kg(-1) (Group 4) or dexmedetomidine 0.25 microg kg(-1) plus lidocaine 0.5 mg kg(-1) (Group 5) were administered at a rate of 0.5 mL s(-1) after tourniquet application. The occlusion was released after 1 min and 5 mL of propofol was injected over 20 s. Pain was evaluated by use of a 10-point verbal analogue scale. Then, the rest of the induction dose of propofol, 3 mL of saline bolus and 0.6 mg kg(-1) of rocuronium, was injected. The response to injection of rocuronium was assessed with a four-point scale (0-3). RESULTS: Groups 1 and 2 were found to have higher propofol injection pain scores than Groups 3, 4 and 5 (P < 0.05). When the study groups were compared according to the overall incidence of withdrawal movements due to rocuronium (1 response) in Groups 1, 2, 3, 4 and 5, they were different (86.7%, 60%, 36.7%, 50% and 40%, respectively) (P < 0.05). Except Group 1, there was no significant difference between the groups according to incidence of withdrawal movement after rocuronium injection (P = 0.325). CONCLUSIONS: Pretreatment with dexmedetomidine is not effective in reducing injection pain of propofol, but may attenuate the hand withdrawal associated to rocuronium, as lidocaine does.

Comparison of ephedrine and ketamine in prevention of injection pain and hypotension due to propofol induction.

BACKGROUND AND OBJECTIVE: This prospective, double-blind, randomized, placebo-controlled study compares the effects of ephedrine and ketamine on injection pain, and hypotension from propofol. METHODS: After obtaining the approval of the Ethics Committee, 75 patients (ASA I-II) scheduled for elective operations with general anaesthesia were divided into three groups. Saline 2 mL (Group S, n = 25), ketamine 0.5 mg kg(-1) (Group K, n = 25) or ephedrine 70 microg kg(-1) (Group E, n = 25) were administered over 5 s after tourniquet application. After releasing the tourniquet, propofol 2 mg kg(-1) was injected in 30 s. Pain was evaluated on a numerical scale (0-10) where 0 represented no pain and 10 the most severe pain possible. Systolic, diastolic blood pressures and heart rates were recorded preoperatively, 1 min after propofol injection, before intubation and 1, 2 and 3 min after intubation in all patients. RESULTS: The incidences of pain in Groups S, E and K were similar (84%, 80% and 72%, respectively). The mean pain score in Group K (2.1, SD 3.1) was significantly lower than those of Groups S and E (4.9, SD 2.6 and 4.6, SD, 3.3, respectively) (P < 0.05). The systolic and diastolic blood pressure values in Group K (120 +/- 27 mmHg) and Group E (123 +/- 21 mmHg) before intubation were significantly higher than that of Group S (104 +/- 25 mmHg) (P < 0.05). There was no significant difference between the mean heart rate values of the groups. CONCLUSIONS: Low dose ketamine or ephedrine pretreatment may prevent hypotension due to propofol induction. Despite the reduction in injection pain intensity after ketamine, the study drugs were found to be ineffective in lowering the injection pain incidence.