RESUMEN
BACKGROUND: Intraoperative somatosensory-evoked potential (SEP) monitoring has become a part of neurosurgical procedures. In this study, we evaluated the effect of dexmedetomidine on SEP monitoring during neurosurgical anesthesia. METHODS: Eight patients scheduled for neurosurgery were studied. Anesthesia was maintained with continuous infusion of propofol at 2 microg x ml(-1) concentration using target controlled infusion (TCI). A loading dose of dexmedetomidine was infused at 6 microg x kg(-1) hr(-1) for 10 min and SEP was recorded. Infusion of dexmedetomidine was continued at 0.5 microg x kg(-1) x min(-1) for 10 min and SEP was recorded. We measured the change of amplitude and latency of SEP (N20-P25) and compared to baseline values. RESULTS: There was no statistically significant change in the cortical SEP amplitude (98.0 +/- 18.1% after a loading dose of dexmedetomidine and 112.7 +/- 16.8% at 0.5 microg x kg(-1) x min(-1) of dexmedetomidine, respectively) or latency (101.5 +/- 1.7% after a loading dose of dexmedetomidine and 101.9 +/- 1.7% at 0.5 microg x kg(-1) x min(-1) of dexmedetomidine, respectively). Mean blood pressure rose from 81 mmHg to 95 mmHg after initiation of dexmedetomidine infusion. Heart rate did not change. CONCLUSIONS: These findings suggest that dexmedetomidine has possibilities to produce an ideal environment as an anesthetic adjunct in patients requiring intrapoerative SEP monitoring.
Asunto(s)
Adyuvantes Anestésicos/farmacología , Agonistas alfa-Adrenérgicos/farmacología , Dexmedetomidina/farmacología , Potenciales Evocados Somatosensoriales/efectos de los fármacos , Monitoreo Intraoperatorio , Adyuvantes Anestésicos/administración & dosificación , Agonistas alfa-Adrenérgicos/administración & dosificación , Anciano , Anestesia , Dexmedetomidina/administración & dosificación , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos , PropofolRESUMEN
BACKGROUND: Plasma levels of D-dimer, soluble fibrin monomer complex (SFMC) and FDP were measured in 40 patients for orthopedic lower extremity surgery, using a recently established monoclonal antibody to clarify if these markers are good indicator of deep vein thrombosis(DVT). METHODS: Subjects were 20 patients for total hip arthroplasty (THA) or total knee arthroplasty (TKA) (group A) and 20 patients for hip fracture surgery (group F). D-dimer, SFMC and FDP were measured at induction of anesthesia. RESULTS: Preoperative values of D-dimer, FMC and FDP in group F were higher than those in group A, and these values in group F were higher than normal values. CONCLUSIONS: It is concluded that plasma levels of D-dimer, SFMC and FDP in the patients with hip fracture were higher than those in the patients scheduled for TKA or THA in perioperative period. These suggest that the patients with hip fracture have high risk of DVT.
Asunto(s)
Artroplastia de Reemplazo de Cadera , Artroplastia de Reemplazo de Rodilla , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Fracturas de Cadera/sangre , Fracturas de Cadera/complicaciones , Cuidados Preoperatorios , Trombosis de la Vena/diagnóstico , Trombosis de la Vena/etiología , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Diagnóstico Precoz , Procedimientos Quirúrgicos Electivos , Femenino , Humanos , Masculino , Persona de Mediana Edad , RiesgoRESUMEN
BACKGROUND: Gum elastic bougie (GEB) is one of the most useful devices for patients whose tracheas are difficult to intubate during anesthetic induction. But no previous study has evaluated the effects of the types of the tracheal tube. We hypothesized that wire-reinforced tracheal tubes were superior to standard tracheal tubes in the success rate of tracheal intubation when using GEB. We compared these two different types of tracheal tubes in using GEB. METHODS: Forty patients were subjected and randomly allocated into two groups; patients intubated with standard tracheal tubes (Group , n = 20) and those with wire-reinforced tracheal tubes (Group S, n = 20). Measured variables were intubation time defined as elapsed time from mouth opening to removal of GEB from tracheal tube, heart rate (HR), and systolic blood pressure(SBP). We also compared trial times of intubation and pharyngeal or laryngeal bleeding as a minor side effect. RESULTS: Trachea was successfully intubated in the frist attempt in 37 patients (92.5%), and the rest of the patients were all intubated at second trial. Intubation times of Group P and Group S were 41.5 +/- 13.9s and 41.3 +/- 11.1s, respectively. There were no significant differences in HR and SBP between the groups. CONCLUSIONS: The type of tracheal tube would not affect the success rate and time of intubation when using gum elastic bougie.
Asunto(s)
Intubación Intratraqueal/instrumentación , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
BACKGROUND: Plasma levels of D-dimer, fibrin monomer complex (FMC) and FDP were measured in 10 patients who underwent hip fracture surgery, using a recently established monoclonal antibody to clarify if these markers are good indicators of deep vein thrombosis (DVT). METHODS: Subjects were 10 (4 male and 6 female) hip fracture patients, aged 87 +/- 6 years. D-dimer, FMC and FDP were measured at induction of anesthesia and 24 hours as well as 6 days after operation. RESULTS: Preoperative values of D-dimer, FMC and FDP were higher than normal values, and these markers remained high during the postoperative period. CONCLUSIONS: It is concluded that plasma levels of D-dimer, FMC and FDP in the patients with hip fracture were high in perioperative period. Among these markers, FMC was the most useful indicator for the diagnosis at the early stage of DVT.
Asunto(s)
Biomarcadores/sangre , Productos de Degradación de Fibrina-Fibrinógeno/análisis , Fracturas de Cadera/cirugía , Trombosis de la Vena/sangre , Anciano de 80 o más Años , Femenino , Humanos , MasculinoRESUMEN
BACKGROUND: The effect of anesthetics on somatosensory evoked potential (SEP) and auditory brain stem response (ABR) has been a subject of intense reseach over the last two decades. In fact, volatile anesthetics have been repeatedly shown to decrease cortical amplitude in a dose-dependent fashion but the information regarding the effect of propofol is incomplete. The purpose of this study was to compare the effects of sevoflurane and propofol on evoked potentials during comparable depth of anesthesia guided by bispectral index (BIS). METHODS: Forty four patients scheduled for neurosurgery were studied. Anesthesia was maintained with intravenous propofol using target controlled infusion (TCI). We measured the change of amplitude and latency of SEP(N20-P25), ABR (V wave) and visual evoked potential (VEP: P100) at three sets of sevoflurane (0%, 1%, 2%) or propofol concentrations (effect site concentration of 1.5, 2.0, 3.0 microug x ml(-1)). BIS monitor was used to measure relative depth of hypnosis. RESULTS: With increasing concentrations of sevoflurane (0, 1% and 2%), SEP showed dose-related reduction in its amplitude, ABR produced less marked changes and VEP showed a significant reduction at 1%. VEP at the propofol concentration of 3.0 microg x ml(-1) was decreased significantly compared with the amplitude at 1.5 microg x ml(-1) concentration. No significant change was observed with SEP and ABR during the change of propofol dosages. BIS values were almost the same with each anesthetics. CONCLUSIONS: VEP was most strongly affected with anesthetics, and ABR showed less marked influence of sevoflurane and propofol. Propofol based TIVA technique would induce less change in evoked potentials than sevoflurane.
Asunto(s)
Anestesia por Inhalación , Potenciales Evocados Auditivos del Tronco Encefálico/efectos de los fármacos , Potenciales Evocados Somatosensoriales/efectos de los fármacos , Potenciales Evocados Visuales/efectos de los fármacos , Éteres Metílicos/farmacología , Procedimientos Neuroquirúrgicos , Propofol/farmacología , Anciano , Anestésicos por Inhalación , Anestésicos Intravenosos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Monitoreo Intraoperatorio , SevofluranoRESUMEN
BACKGROUND: Decreased mouth opening and limited neck mobility sometimes make direct laryngoscopy or tracheal intubation difficult and compromise the safety in establishing the airway during induction of general anesthesia. Recent report indicated that mouth opening was related to the craniocervical position in awake subjects. The query about whether the neck position modulate the mouth opening during anesthetic induction under paralyzed condition is not clarified. We hypothesized that the neck extension and the flexion induce changes in inter-incisor distance (IID) during anesthetic induction. METHODS: Thirty relatively young patients for general anesthesia were (male; 20, female; 10) subjected. IID was measured with his/her neck positioned flexed, neutral and extended in the sagittal plane, each at preanesthetic awake period, and during anesthetic induction period. The effect of sniffing position on the mouth opening was also studied. RESULTS: At preanesthetic period, IID (mean +/- SD in mm) at neck flexion (37.4 +/- 7.8) was significantly shorter than both at neutral (44.1 +/- 7.5) and at extension (47.4 +/- 7.0). During induction, significant increase in IID was observed as patients' neck position changed from flexed (31.8 +/- 5.4) to neutral (36.6 +/- 5.4), and extended, (41.7 +/- 8.3). Sniffing position did not affect the mouth opening both at preanesthetic and during anesthetic induction period. CONCLUSIONS: Craniocervical extension may play a desirable role in the airway management with mouth opening widely during anesthetic induction under neuromuscular blockade.
Asunto(s)
Anestesia General , Intubación Intratraqueal , Boca/fisiología , Postura , Adulto , Femenino , Humanos , Laringoscopía , Masculino , Persona de Mediana Edad , Boca/anatomía & histología , Cuello/fisiologíaRESUMEN
STUDY OBJECTIVE: To investigate the effect of propofol and midazolam on cardiac autonomic nervous system (CANS) activity during combined spinal-epidural anesthesia. DESIGN: Prospective, clinical study. SETTING: Operating room of a university hospital. PATIENTS: Forty ASA physical status I and II patients scheduled for knee surgery. INTERVENTION: Patients were randomized to receive sedation with either propofol or midazolam. MEASUREMENTS: Heart rate (HR), HR variability (HRV), systolic arterial pressure (SAP), and SAP variability (SAPV) were used for the analysis. These values were measured at the preanesthetic period, after intrathecal injection for spinal anesthesia, after sedation with propofol or midazolam, and just before the end of surgery with sedation. Cross-spectral analyses of the HR and SAP data were assessed to quantify the frequency-related coherence spectra and phase spectra. MAIN RESULTS: Spinal anesthesia itself had no effect on power spectral changes in both groups. After sedation, as for HRV, high-frequency (HF) power (HF, 0.15-0.40 Hz) did not change, whereas low-frequency (LF) power (LF, 0.04-0.15 Hz) and LF/HF, an indicator of CANS balance, significantly decreased with propofol. Further, coherence in cross-spectra presented depression in the LF band area after sedation with propofol. Before the end of surgery with sedation, LF and LF/HF in both HRV and SAPV were correlated with age in those with propofol; however, scarce relation was observed in those who received midazolam. CONCLUSIONS: Propofol was more potent than midazolam in causing CANS activity to be sympatholytic during combined spinal and epidural anesthesia and which was correlated with age only with propofol.
Asunto(s)
Anestesia Epidural , Anestesia Raquidea , Anestésicos Intravenosos , Sistema Nervioso Autónomo/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Midazolam , Propofol , Adulto , Artroscopía , Barorreflejo/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Rodilla/cirugía , Masculino , Mecánica RespiratoriaRESUMEN
Artificial ventilation with positive end-expiratory pressure (PEEP) is commonly applied for brain damaged patients. However, the effect of the ventilation on brain function, including cardiovascular autonomic nervous system (CANS) activity, is not well elucidated. In order to investigate the effect of 5 cmH2O PEEP on CANS activity in brain damaged rabbits under general anesthesia, we produced acute brain damage by intracranial balloon inflation. Measurements were made before (control) and after application of PEEP, and after inflation with incremental volume of the balloon. Power spectral analyses of heart rate variability (HRV) and systolic arterial pressure variability (SAPV) were used for the assessment of CANS activity. Spectral powers in the low-frequency range of 0.04 to 0.40 Hz (LF) and high-frequency range of 0.75 to 1.40 Hz (HF) were computed, and their ratio LF/HF was assessed as the neural balance of CANS. The animals in group P were ventilated with 5 cmH2O PEEP, while those in group Z were ventilated with zero end-expiratory pressure. Colored microsphere counting was used for the assessment of brain circulation. In the results, PEEP had no effect on HRV and SAPV parameters before induction of brain damage. After inflation with incremental volume of the balloon, log (HF) and log (LF) in group P were lower than in group Z in HRV analysis, and log (LF) in group P was lower than in group Z in SAPV analysis. Microsphere counting revealed that brain blood flow was reduced during the progression of brain damage and showed a significant difference after application of PEEP between the groups. We concluded that 5 cmH2O PEEP depressed CANS activity during the progression of brain damage in rabbits and that this was partly due to aggravated brain function induced by PEEP.