Efeitos antimicrobianos de cetamina em combinação com propofol: um estudo in vitro / The antimicrobial effects of ketamine combined with propofol: an in vitro study / Efectos antimicrobianos de la cetamina en combinación con el propofol: un estudio in vitro

EXPERIÊNCIA E OBJETIVOS: Cetamina e propofol são os anestésicos gerais que também exibem efeitos antimicrobianos e promotores do crescimento microbiano, respectivamente. Embora esses agentes sejam frequentemente aplicados em combinação durante o uso clínico, não há dados sobre seu efeito total no crescimento microbiano na administração combinada. Nesse estudo, investigamos o crescimento de alguns microrganismos em uma mistura de cetamina e propofol. MÉTODO: Nesse estudo, utilizamos cepas padronizadas: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa e Candida albicans. Realizamos uma análise de tempo-crescimento para avaliar as taxas de crescimento microbiano em propofol 1%. A atividade antimicrobiana de cetamina, isoladamente e em propofol, foi estudada pelo método de microdiluição. RESULTADOS: Em propofol, as cepas estudadas cresceram de concentrações de 10³-10(4) ufc/mL para > 10(5) ufc/mL, dentro de 8-16 horas, dependendo do tipo de microrganismo. Foram determinadas a concentração inibitória mínima (CIM) e a concentração bactericida mínima (CBM) (para Candida, concentração fungicida mínima) de cetamina, como se segue (CIM, CBM): E. coli 312,5, 312,5 µg/mL; S.aureus 19,5, 156 µg/mL; P. aeruginosa 312,5, 625 µg/mL; e C. albicans 156, 156 µg/mL. Na mistura cetamina + propofol, cetamina exibiu atividade antimicrobiana para E. coli, P. aeruginosa e C. albicans em CBMs a 1250, 625 e 625 µg/mL, respectivamente. O crescimento de S. aureus não foi inibido nessa mistura (concentração de cetamina = 1250 µg/mL). CONCLUSÃO: Cetamina preservou sua atividade antimicrobiana de maneira dose-dependente contra alguns microrganismos em propofol, que é robusta solução promotora de crescimento microbiano. O uso combinado de cetamina e propofol na aplicação clínica de rotina pode diminuir o risco de infecção causada por contaminação acidental. Entretanto, deve-se ter em mente que cetamina não pode reduzir todas as ameaças patogênicas na mistura com propofol.

BACKGROUND AND OBJECTIVES: Ketamine and propofol are the general anesthetics that also have antimicrobial and microbial growth-promoting effects, respectively. Although these agents are frequently applied together during clinical use, there is no data about their total effect on microbial growth when combined. In this study, we investigated some organisms' growth in a ketamine and propofol mixture. METHOD: We used standard strains including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans in this study. Time-growth analysis was performed to assess microbial growth rates in 1% propofol. Antimicrobial activity of ketamine, alone and in propofol was studied with microdilution method. RESULTS: In propofol, studied strains grew from 10³-10(4) cfu/mL to >10(5) cfu/mL concentrations within 8-16 hours depending on the type of organism. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) (for candida, minimal fungicidal concentration) of ketamine were determined as follows (MIC, MBC): E.coli 312.5, 312.5 µg/mL; S.aureus 19.5, 156 µg/mL; P.aeruginosa 312.5, 625 µg/mL; and C.albicans 156, 156 µg/ml. In ketamine+propofol mixture, ketamine exhibited antimicrobial activity to E.coli, P.aeruginosa and C.albicans as MBCs at 1250, 625 and 625 µg/mL, respectively. Growth of S. aureus was not inhibited in this mixture (ketamine concentration=1250 µg/mL). CONCLUSION: Ketamine has sustained its antimicrobial activity in a dose-dependent manner against some organisms in propofol, which is a strong microbial growth-promoting solution. Combined use of ketamine and propofol in routine clinical application may reduce the risk of infection caused by accidental contamination. However, one must keep in mind that ketamine cannot reduce all pathogenic threats in propofol mixture.

EXPERIENCIA Y OBJETIVOS: La Cetamina y el propofol son los anestésicos generales que también tienen efectos antimicrobianos y son los promotores del crecimiento microbiano, respectivamente. Aunque esos agentes sean frecuentemente aplicados en combinación durante el uso clínico, no hay datos sobre su efecto total en el crecimiento microbiano en la administración combinada. En ese estudio, investigamos el crecimiento de algunos microrganismos en una mezcla de cetamina y propofol. MÉTODO: En este estudio, utilizamos cepas estandarizadas: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa y Candida albicans. Realizamos un análisis de tiempo-crecimiento para evaluar las tasas de crecimiento microbiano en el propofol al 1%. La actividad antimicrobiana de cetamina, aisladamente y en propofol, fue estudiada por el método de microdilución. RESULTADOS: En el propofol, las cepas estudiadas crecieron de concentraciones de 10³-10(4) ufc/mL para #> 10(5) ufc/mL, dentro de 8-16 horas, dependiendo del tipo de microrganismo. Fueron determinadas la concentración inhibitoria mínima (CIM) y la concentración bactericida mínima (CBM) (para Candida, concentración fungicida mínima) de cetamina, como vemos (CIM, CBM): E. coli 312,5, 312,5 µg/mL; S.aureus 19,5, 156 µg/mL; P. aeruginosa 312,5, 625 µg/mL; y C. albicans 156, 156 µg/ml. En la mezcla cetamina + propofol, la cetamina mostró una actividad antimicrobiana para E. coli, P. aeruginosa y C. albicans en CBMs a 1250, 625 y 625 µg/mL, respectivamente. El crecimiento de S. aureus no se inhibió en esa mezcla (concentración de cetamina = 1250 µg/mL). CONCLUSIONES: La cetamina preservó su actividad antimicrobiana de manera dosis-dependiente contra algunos microrganismos en propofol, que es una robusta solución que promueve el crecimiento microbiano. El uso combinado de cetamina y propofol en la aplicación clínica de rutina puede disminuir el riesgo de infección causada por la contaminación accidental. Sin embargo, debemos tener presente que la cetamina no puede reducir todas las amenazas patógenas en la mezcla con el propofol.

The antimicrobial effects of ketamine combined with propofol: An in vitro study.

BACKGROUND AND OBJECTIVES: Ketamine and propofol are the general anesthetics that also have antimicrobial and microbial growth-promoting effects, respectively. Although these agents are frequently applied together during clinical use, there is no data about their total effect on microbial growth when combined. In this study, we investigated some organisms' growth in a ketamine and propofol mixture. METHOD: We used standard strains including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans in this study. Time-growth analysis was performed to assess microbial growth rates in 1% propofol. Antimicrobial activity of ketamine, alone and in propofol was studied with microdilution method. RESULTS: In propofol, studied strains grew from 10(3)-10(4) cfu/mL to ≥10(5) cfu/mL concentrations within 8-16 hours depending on the type of organism. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) (for candida, minimal fungicidal concentration) of ketamine were determined as follows (MIC, MBC): E.coli 312.5, 312.5 µg/mL; S.aureus 19.5, 156 µg/mL; P.aeruginosa 312.5, 625 µg/mL; and C.albicans 156, 156 µg/ml. In ketamine+propofol mixture, ketamine exhibited antimicrobial activity to E.coli, P.aeruginosa and C.albicans as MBCs at 1250, 625 and 625 µg/mL, respectively. Growth of S. aureus was not inhibited in this mixture (ketamine concentration=1250 µg/mL). CONCLUSION: Ketamine has sustained its antimicrobial activity in a dose-dependent manner against some organisms in propofol, which is a strong microbial growth-promoting solution. Combined use of ketamine and propofol in routine clinical application may reduce the risk of infection caused by accidental contamination. However, one must keep in mind that ketamine cannot reduce all pathogenic threats in propofol mixture.

Effects of 2 different doses of pregabalin on morphine consumption and pain after abdominal hysterectomy: a randomized, double-blind clinical trial.

BACKGROUND: Pregabalin has a similar pharmacologic profile to that of its developmental predecessor gabapentin but has shown greater analgesic activity in rodent models of neuropathic pain. OBJECTIVE: The objective of the study was to compare the effects of 2 different doses of pregabalin and placebo on postoperative pain and morphine consumption. METHODS: Ninety patients who underwent abdominal hysterectomy were included in the study and randomly divided into 3 groups in a doubled-blinded manner. They were given 150 mg of pregabalin (group P300, n = 30), 300 mg of pregabalin (group P600, n = 30), or placebo capsules (group C, n = 30) 4 hours before the induction of anesthesia; they received a second dose of the drug 12 hours postoperatively. Morphine consumption, nausea, and vomiting, visual analogue scale-pain intensity (VAS-PI), sedation scores, and dissatisfaction scores were recorded in the postanesthesia care unit (PACU) and at 2, 4, 6, and 24 hours after operation. RESULTS: Morphine consumption at 24 hours was 40.80 (3.42) mg, 33.79 (5.77) mg, and 46.97 (6.67) mg in groups P300, P600, and C, respectively (P < 0.001). VAS-PI scores at movement and at rest in the PACU and at 2, 4, and 6 hours decreased in group P600 (P < 0.01). In the PACU and at 2, 4, and 6 hours, the sedation scores were increased in group P600 compared with the scores in group C (P < 0.001, P < 0.001, P = 0.01, P = 0.006, respectively). Patient satisfaction was higher in group P600 than in group C for all time points (P < 0.001, P < 0.001, P < 0.001, P = 0.001, P < 0.001, respectively). There were no statistically significant differences between the groups for side effects such as nausea, vomiting, and dizziness (P = 0.58). CONCLUSIONS: Pregabalin at a total dose of 600 mg, administered before operation and at 12 hours postoperatively after abdominal hysterectomy, reduced morphine consumption and pain intensity and increased patient satisfaction. No significant differences in side effects were observed between the study groups.

Obstetric admissions to the intensive care unit in a tertiary referral hospital.

PURPOSE: The present study was conducted to evaluate the obstetric admissions to the intensive care unit (ICU) in the setting of a tertiary referral hospital in an attempt to identify the risk factors influencing maternal outcome. MATERIALS AND METHODS: All of the obstetric patients who seeked care for delivery at the emergency department and who were admitted to the ICU between January 2006 to July 2009 were retrospectively identified. The Simplified Acute Physiology Score (SAPS II) was calculated and the maternal mortality rate was estimated for each patient. The mean SAPS II scores and the mean estimated maternal mortality rates for the surviving patients and the nonsurviving patients were compared. RESULTS: Seventy-three obstetric patients were admitted to the ICU. There were 9 maternal deaths and 24 fetal deaths. For the surviving group of patients, the mean SAPS II score was 34 and estimated maternal mortality rate was 20%, whereas for the nonsurviving group of patients, the SAPS II score was 64 and estimated maternal mortality rate was 73%. The difference between the surviving group of patients and the nonsurviving group of patients was statistically significant regarding both the mean SAPS II scores and the mean estimated maternal mortality rates. CONCLUSIONS: Pregnancy-induced hypertensive disorders and hemorrhage appear as the major risk factors influencing maternal outcome in obstetric patients. Considering that the use of the SAPS II scores have enabled the reliable estimation of the mortality rates in the present study, the attempts at defining the focus of care for the obstetric patients who bear the major risk factors and who are admitted to the ICU should be carried out under the guidance of the ICU scoring systems such as the SAPS II.

Intensive care of a weils disease with multiorgan failure.

UNLABELLED: Leptospirosis is a commonly encountered type of zoonosis, especially in tropical regions. There is insufficient data regarding its frequency in non-tropical regions such as Turkey. Although leptospirosis presents with a mild icteric form in nearly 90% of cases, it can lead to Weils disease characterized by fever as well as fulminant hepatorenal and respiratory failure, in approximately 5 - 10% of cases. In this case report, we present a patient with Weil's disease, complicated with multiorgan failure. KEYWORDS: Weils disease; Leptospirosis; Multiorgan failure.

Remifentanil and propofol for tracheal intubation without muscle relaxant in children: the effects of ketamine.

BACKGROUND AND OBJECTIVE: Remifentanil and propofol have been proposed for intubation without muscle relaxant to avoid the adverse effects of muscle relaxants in children. We hypothesized that the addition of ketamine to remifentanil and propofol would improve intubating conditions and provide haemodynamic stability. METHODS: We studied 88 children (3-12 years) undergoing elective surgery. Group K received ketamine 0.5mgkg(-1), remifentanil 3microgkg(-1) and propofol 3mgkg(-1). Group C received isotonic saline instead of ketamine, all other study drugs were same as in group K. Sixty seconds after administration of propofol, laryngoscopy and tracheal intubation were performed. Intubating conditions were graded. Mean arterial pressure (MAP), heart rate (HR) and SpO(2) were recorded. RESULTS: The intubating conditions were regarded as clinically acceptable in 39 out of 44 (89%) children in group K and in 36 out of 44 (82%) children in group C. Although there was no failed intubation in group K, the intubation failed in six children in group C (P<0.05). Tracheal intubation failed in 4/6 children because of severe coughing and/or limb movement, and in 2/6 children because of closed vocal cords. Scores for limb movement were significantly lower in group K than in group C. When compared with baseline, HR and MAP significantly decreased in both groups during the study (P<0.05). CONCLUSION: The addition of ketamine to remifentanil and propofol prevented failed intubation and slightly increased the percentage of acceptable intubating conditions. Ketamine had no influence on haemodynamic changes following remifentanil and propofol administration in given doses.

Does leflunomide attenuate the sepsis-induced acute lung injury?

The organ that is affected first and most severely in intraabdominal sepsis is the lung. Oxygen radicals and active neutrophils in the lung are important sources for severe pulmonary inflammation leading to acute lung injury (ALI)/acute respiratory distress syndrome. The aim of this study was to investigate the effects of leflunomide, an immunomodulatory agent, on oxidant/antioxidant status with nitric oxide (NO) level and myeloperoxidase (MPO) activity in rats with sepsis-induced ALI. Fifty male Wistar albino rats were divided into five groups: control, sham, sepsis, leflunomide (10 mg/kg, intragastrically for two doses with an 8 h interval prior to the experiment) and sepsis + leflunomide. After the animals were anesthetized with ketamine and xylazine, the abdominal cavity was opened and ligated just below the ileocaecal valve with 3-0 silk. The antimesentric surface of the cecum was perforated and the cecum was gently compressed until fecal matter was extruded to induce sepsis. None of the rats received antibiotics during the experimental procedures. The experiment was ended 24 h after cecal ligation puncture (CLP) with the cervical dislocation under anesthesia. The lung tissues were removed for analysis of biochemical parameters and light microscopic investigation. The lung superoxide dismutase (SOD), catalase and glutathione peroxidase activities were decreased in the sepsis group as compared to the group control, sham, leflunomide and sepsis + leflunomide (P < 0.05), and SOD activity were significantly higher in group sepsis + leflunomide than sham, control, leflunomide and sepsis group (P < 0.05). The lung MPO, malondialdehyde (MDA), protein carbonyl and NO levels were higher in the sepsis group when compared to group control, sham, leflunomide and sepsis + leflunomide (P < 0.05), and MPO, MDA and NO levels were higher in the sepsis + leflunomide group than in the sham, control and leflunomide group (P < 0.05). The light microscopic evaluation showed that pulmonary architecture was preserved, and infiltration of neutrophil and edema decreased in sepsis + leflunomide group. The grade of alveolar damage was significantly decreased in sepsis + leflunomide group in comparison with sepsis group (P < 0.05). Our findings suggested that leflunomide attenuated the lung injury after CLP-induced sepsis by inhibition of neutrophils accumulation and increasing endogenous antioxidant capacity.

Lornoxicam and ondansetron for the prevention of intrathecal fentanyl-induced pruritus.

PURPOSE: In this randomized, double-blind study, we aimed to compare the effectiveness of lornoxicam and ondansetron for the prevention of intrathecal fentanyl-induced pruritus in patients undergoing cesarean section. METHODS: One hundred and eight parturients (American Society of Anesthesiologists [ASA] I-II status) requesting neuraxial analgesia by a combined spinal-epidural (CSE) technique were recruited for this study. A CSE technique was performed and anesthesia was achieved with fentanyl 25 microg and hyperbaric bupivacaine 12 mg. Patients were randomly allocated to three groups, each with 36 participants. Immediately following delivery, patients received either lornoxicam 8 mg IV (group L; n = 36), ondansetron 8 mg IV (group O; n = 36), or normal saline 2 ml IV (group P; n = 36). Pruritus, pain, and nausea and vomiting scores were recorded during the initial 24 h postoperatively. RESULTS: The incidence of pruritus was significantly lower in group O from 4 to 12 h postoperatively when compared to that in group L and group P. According to the pruritus grading system we used, the number of patients without pruritus was significantly higher in group O when compared to that in group L and group P. The number of patients experiencing moderate pruritus was significantly lower in group O when compared to that in group P. CONCLUSION: We observed that the administration of 8 mg IV lornoxicam failed to prevent intrathecal fentanyl-induced pruritus in parturients. Also, our data confirmed that ondansetron is likely to attenuate intrathecal fentanyl-induced pruritus.

Comparison of the antibacterial activity of lidocaine 1% versus alkalinized lidocaine in vitro.

BACKGROUND: Infections after epidural and spinal blocks are rare. The topical anesthetic liclocaine used in these procedures has been found to have antibacterial effects on various microorganisms. OBJECTIVE: The aim of this study was to assess the antibacterial effects of alkalinized liclocaine on Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. METHODS: Lidocaine 2%, alkalinized lidocaine, and physiologic saline (as a control solution) were added to standard bacterial preparations. The final concentration of the lidocaine was 10 mg/mL (1%). At baseline and 3 and 6 hours after incubation at 37°C, 3-mL aliquots were vortexed and pipetted into sterile polystyrene spectrophotometer cuvettes. Baseline referred to the end of the period of preparation of the solution (≤20 minutes). Growth was measured as the optical density at a wavelength of 540 nm. RESULTS: Compared with the control, lidocaine significantly inhibited the growth of S aureus, E coli, and P aeruginosa at baseline and 3 and 6 hours after incubation (all, P < 0.05). Alkalinized lidocaine significantly inhibited the growth of S aureus at baseline and 3 and 6 hours (all, P < 0.05), while it significantly inhibited the growth of E coli and P aeruginosa only at 6 hours (both, P < 0.05). The growth of E coli was significantly less in lidocaine than in alkalinized lidocaine at 0 and 3 hours (both, P < 0.05). CONCLUSION: The antibacterial effect of lidocaine 1% on S aureus was not changed after alkalinization. The effect of alkalinized lidocaine on E coli and P aeruginosa was significant only at 6 hours. Lidocaine significantly inhibited the growth of these 3 microorganisms at all study periods.

Hemodynamic, hepatorenal, and postoperative effects of desflurane-fentanyl and midazolam-fentanyl anesthesia in coronary artery bypass surgery.

OBJECTIVE: The purpose of this study was to compare the hemodynamic, hepatorenal, and postoperative effects of desflurane-fentanyl and midazolam-fentanyl anesthesia during coronary artery bypass surgery. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Sixty patients undergoing elective coronary artery bypass grafting surgery with ejection fraction more than 45%. INTERVENTIONS: Anesthesia was induced with etomidate, 0.2 mg/kg, and fentanyl, 5 microg/kg, in group D (n = 30) and with midazolam, 0.1 to 0.3 mg/kg, and fentanyl, 5 microg/kg, in group M (n = 30). Anesthesia was maintained with desflurane, 2% to 6%, and fentanyl, 15 to 25 microg/kg, in group D and midazolam infusion, 0.1 to 0.5 mg/kg/h, and fentanyl, 15 to 25 microg/kg, in group M. MEASUREMENTS AND MAIN RESULTS: Hemodynamic monitoring included a 5-lead electrocardiogram, a radial artery catheter, and a pulmonary artery catheter. Data were obtained before induction of anesthesia (t0), after induction of anesthesia (t1), after intubation (t2), after surgical incision (t3), after sternotomy (t4), before cardiopulmonary bypass (t5), after protamine infusion (t6), and at the end of the surgery (t7). Blood samples were obtained to measure total bilirubin, aspartate aminotransferase, gamma glutamyl transferase, lactate dehydrogenase, alkaline phosphatase, creatinine, and blood urea nitrogen just before induction of anesthesia and at the first, fourth, and 14th days postoperatively. CONCLUSIONS: Intraoperative hemodynamic responses were similar in both groups, and transient hepatic and renal dysfunctions were observed in the postoperative period in both groups. The extubation and intensive care unit discharge times were found to be shorter in the desflurane-fentanyl group.

Small-dose capsaicin reduces systemic inflammatory responses in septic rats.

We investigated the influence of small- and large-dose capsaicin in modulating systemic inflammatory responses during different stages of sepsis in rats. Rats were divided into six groups: group C, control; group S, sepsis; group CLC, small dose of capsaicin (1 mg/kg subcutaneously); group SLC, small dose of capsaicin plus sepsis; group CHC, large dose of capsaicin (150 mg/kg subcutaneously); group SHC, large dose of capsaicin plus sepsis. Rats were made septic by cecal ligation and puncture (CLP). Each group was subdivided into two subgroups. The animals were killed at 9 or 18 h after CLP. Plasma concentrations of calcitonin gene-related peptide (CGRP), tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-10, and total nitrite/nitrate (NOx) were measured. Superoxide dismutase and malondialdehyde (MDA) were determined in liver, lung, and heart tissues. CGRP was increased in groups S, CLC, and SLC when compared with the other groups. In the SLC group, plasma concentrations of TNF-alpha, IL-6, NOx, and tissue MDA levels were reduced and IL-10 level was increased when compared with groups S and SHC 18 h after CLP (P < 0.05). Small-dose capsaicin treatment increased antiinflammatory IL-10 levels and attenuated the increases in proinflammatory cytokines, NOx, and tissue MDA in septic rats.

The effects of irrigation fluid volume and irrigation time on fluid electrolyte balance and hemodynamics in percutaneous nephrolithotripsy.

OBJECTIVE: to determine fluid-electrolyte and hemodynamics changes and complications associated with irrigation fluid volume and time in percutaneous nephrolithotripsy in that 0.9% NaCl was used as irrigant. METHODS: Standard anaesthetic procedures were performed to 6 women and 16 men. Mean arterial pressure, heart rate, central venous pressure, Na+, K+, osmolality, haemoglobin, haematocrit were recorded before, during and after irrigation every 10 minutes. Creatinine and blood urea nitrogen were determined before and after irrigation. Moreover, the operation and irrigation times, irrigation fluid volume, total fluid output versus input, blood transfusions and complications were recorded. RESULTS: Mean arterial pressure, heart rate, central venous pressure, Na+, K+, osmolality did not change significantly during and after irrigation and no relationship was observed between those with irrigation volume and time. Creatinine and blood urea nitrogen values during and after irrigation did not change significantly versus those before irrigation. Although no blood transfusion was needed for any case during the procedure, it was necessary for two cases after the procedure. One case with pneumothorax that developed during procedure was treated by inserting a thoracic tube. CONCLUSION: There were no significant changes in fluid-electrolyte balance and hemodynamics related to both irrigation fluid volume and irrigation time when 0.9% NaCl was used in PNL.

The effects of single-dose dexamethasone on wound healing in rats.

UNLABELLED: Dexamethasone effectively decreases the incidence of nausea and vomiting among pediatric and adult patients. In this study, we evaluated the effects of single-dose dexamethasone on wound healing in a prospective, randomized, experimental animal model. Anesthesia was induced with thiopental 100 mg/kg intraperitoneally. Dexamethasone 1 mg/kg was administered intraperitoneally in a dexamethasone group, and physiological saline was administered in a control group. Collagenization, epithelization, and fibroblast content were significantly less in the dexamethasone group compared with the control group (P values of 0.002, 0.041, and 0.023, respectively). The vascularity and the degree of inflammatory cells were more intense in the dexamethasone group compared with the control group (P values of 0.023 and 0.002, respectively). The white blood cell count was similar in the control (7.84 +/- 2.09) and dexamethasone (6.98 +/- 2.12) groups. The mean hydroxyproline level was 0.72 +/- 0.13 mg/g in the dexamethasone and 1.03 +/- 0.19 mg/g in the control group. Hydroxyproline levels were significantly less in the dexamethasone group (P = 0.001). We conclude that dexamethasone at 1 mg/kg may have negative effects on wound healing. IMPLICATIONS: We evaluated the effects of dexamethasone on wound healing in a prospective, randomized, experimental animal model. Our results show that dexamethasone at 1 mg/kg may have negative effects on wound healing.

Remifentanil with thiopental for tracheal intubation without muscle relaxants.

UNLABELLED: Tracheal intubation may be accomplished with remifentanil and a non-opioid IV anesthetic without a muscle relaxant. In this study, we evaluated in double-blinded, prospective, randomized manner the dose requirements for remifentanil with thiopental without muscle relaxant administration to obtain clinically acceptable intubation conditions and cardiovascular responses. After premedication with midazolam 0.03 mg/kg IV, 105 patients were randomized equally to one of three study groups, each receiving the following: remifentanil 2 micro g/kg (Group I), 3 micro g/kg (Group II), and 4 micro g/kg (Group III). Remifentanil was administered over 30 s, and anesthesia was induced with thiopental 5 mg/kg. Tracheal intubation conditions were assessed by the anesthesiologist performing the intubation as: (a) excellent, (b) satisfactory, (c) fair, and (d) unsatisfactory. There were no statistically significant differences among groups regarding to demographic data. Blood pressure and heart rate did not increase in any group after accomplishing intubation. There was a significant improvement in intubation conditions between Groups I and II, I and III, and II and III (P < 0.001). We conclude that remifentanil 4 micro g/kg administered before thiopental 5 mg/kg provided excellent or satisfactory intubation conditions in 94% of patients and prevented cardiovascular responses to intubation. IMPLICATIONS: We evaluated in a double-blinded manner the dose requirements for remifentanil with thiopental without muscle relaxants for obtaining acceptable intubation condition. Our results show that remifentanil 4 micro g/kg administered before thiopental provided excellent or satisfactory intubation condition in 94% of patients.

The use of magnesium to prevent laryngospasm after tonsillectomy and adenoidectomy: a preliminary study.

BACKGROUND: Laryngospasm is the most common cause of upper airway obstruction after tracheal extubation. Magnesium has a central nervous system depressant property, which contributes to the depth of anaesthesia. It also has calcium antagonist properties, which provide muscle relaxation. In this study, we aimed to determine the effect of magnesium on preventing laryngospasm. METHODS: After approval of the Ethics Committee and informed parental consent, 40 patients, ASA I-II, aged 3-12 years, who were scheduled for tonsillectomy or/and adenoidectomy, were randomly divided into two groups. Anaesthesia was induced with sevoflurane, lidocaine 1 mg x kg-1, alfentanil 10 micro g x kg-1, vecuronium 0.1 mg x kg-1 and maintained with sevoflurane 2% and 60% nitrous oxide in oxygen. After intubation, patients in group I received 15 mg.kg-1 magnesium in 30 ml 0.9% NaCl over 20 min. Patients in group II received 0.9% NaCl alone in the same volume. After reversal of neuromuscular blockade, all patients were extubated at a very deep plane of anaesthesia. The incidence of laryngospasm was determined until the time of discharge from the postanaesthesia care unit. RESULTS: Although laryngospasm was not observed in group I, it was observed in five patients in group II (25%). The incidence of laryngospasm in group II was significantly higher than group I. The plasma magnesium concentrations were significantly higher in group I than group II. CONCLUSIONS: We found a significant decrease in the incidence of laryngospasm in paediatric patients receiving magnesium. It is suggested that the use of intravenous magnesium intraoperatively may prevent laryngospasm.