RESUMEN
The German airway management guidelines are intended to serve as an orientation and decision-making aid and thus contribute to the optimal care of patients undergoing anesthesiologic- and intensive medical care. As part of the pre-anesthesiologic evaluation, anatomical and physiological indications for difficult mask ventilation and intubation shall be evaluated. This includes the assessment of mouth opening, dental status, mandibular protrusion, cervical spine mobility and existing pathologies. The airway shall be secured while maintaining spontaneous breathing if there are predictors or anamnestic indications of difficult or impossible mask ventilation and/or endotracheal intubation. Various techniques can be used here. If there is an unexpectedly difficult airway, a video laryngoscope is recommended after unsuccessful direct laryngoscopy, consequently a video laryngoscope must be available at every anesthesiology workplace. The airway shall primarily be secured with a video laryngoscope in critically ill- and patients at risk of aspiration. Securing the airway using translaryngeal and transtracheal techniques is the "ultima ratio" in airway management. The performance or supervision of airway management in the intensive care unit is the responsibility of experienced physicians and nursing staff. Appropriate education and regular training are essential. Clear communication and interaction between team members are mandatory before every airway management procedure. Once the airway has been secured, the correct position of the endotracheal tube must be verified using capnography.
RESUMEN
Follow-up after acute myocarditis is important to detect persisting myocardial dysfunction. However, recovery of atrial function has not been evaluated after acute myocarditis so far. Thirty-five patients with strictly defined acute myocarditis underwent cardiovascular magnetic resonance (CMR, 1.5 T) in the acute stage at baseline (BL) and at 3 months follow-up (FU). The study population included 13 patients with biopsy-proven "cardiomyopathy-like" myocarditis (CLM) and 22 patients with "infarct-like" (ILM) clinical presentation. CMR feature tracking (FT) was performed on conventional cine SSFP sequences. Median LA-GLS increased from 33.2 (14.5; 39.2) at BL to 37.0% (25.2; 44.1, P = 0.0018) at FU in the entire study population. Median LA-GLS also increased from 36.7 (26.5; 42.3) at BL to 41.3% (34.5; 44.8, P = 0.0262) at FU in the ILM subgroup and from 11.3 (6.4; 21.1) at BL to 21.4% (14.2; 30.7, P = 0.0186) at FU in the CLM subgroup. Median RA-GLS significantly increased from BL with 30.8 (22.5; 37.0) to FU with 33.7% (26.8; 45.4, P = 0.0027) in the entire study population. Median RA-GLS also significantly increased from 32.7 (25.8; 41.0) at BL to 35.8% (27.7; 48.0, P = 0.0495) at FU in the ILM subgroup and from 22.8 (13.1; 33.9) at BL to 31.0% (26.0; 40.8, P = 0.0266) at FU in the CLM subgroup. Our findings demonstrate recovery of LA and RA function by CMR-FT strain analyses in patients after acute myocarditis independent from clinical presentation. Monitoring of atrial strain could be an important tool for an individual assessment of healing after acute myocarditis.
Asunto(s)
Miocarditis , Humanos , Miocarditis/diagnóstico por imagen , Valor Predictivo de las Pruebas , Imagen por Resonancia Magnética , Función Atrial , Espectroscopía de Resonancia MagnéticaRESUMEN
BACKGROUND: The evaluation of German postanesthesia questionnaires is often restricted to inpatient medical care. The anesthesiological questionnaire for patients (ANP) has previously been validated only after medical care of inpatients. Therefore, the aim of the present study was to evaluate the validity of the ANP in the context of outpatient surgery and anesthesia. METHODS: Data from 4547 patients (mean age 18-89â¯years, sex: m/f, 55%/45%), scheduled for ambulatory orthopedic and trauma surgery, were analyzed. All patients received a standard induction of anesthesia with propofol, sufentanil and 4â¯mg dexamethasone. Maintenance of anesthesia was achieved with a balanced technique comprising volatile anesthesia (either sevoflurane or desflurane) and sufentanil. In addition, patients undergoing operations on the anterior cruciate ligament received a femoral nerve block with 12-15â¯ml 0.5% ropivacaine. Of the patients 13% remained in hospital overnight as a result of complex operations (combined anterior and posterior cruciate ligament repair, hip arthroscopy and 10% of those undergoing shoulder operations). Before discharge from the recovery room, patients were asked to answer questions with respect to postoperative symptoms 1h after anesthesia (ESNA 19 items), at the time of interview (ABZ 17 items) and about overall patient satisfaction (10 items). These results were matched with the type of procedure and time data from the patient administration system. All data were analyzed descriptively using parametrical tests. RESULTS: At both time points, pain in the area of the operation was the predominant symptom (ESNA: 77,1%; ABZ: 74,3%). Pain after shoulder arthroscopy was more severe compared to knee arthroscopy, both with and without repair of the anterior cruciate ligament. Most of the adverse symptoms decreased significantly (pâ¯≤â¯0.001) with time, demonstrating progressive recovery of the patient. Patient discomfort was more likely to occur in female than in male patients, and female patients were more likely to be dissatisfied with the progress of recovery. The risk of experiencing adverse symptoms after anesthesia was higher for female than for male patients; this was most apparent for feeling cold (odds ratio, OR 4.08) and nausea and vomiting (OR 3.45). Younger patients (18-40â¯years) were more likely to express discomfort than both groups of older patients (41-60â¯years and 61-89â¯years). Accordingly, younger patients had lower satisfaction levels with respect to both anesthesia and overall perioperative care, and the progress of recovery. Postoperative nausea and vomiting (PONV) were linked to younger age, female sex, and longer procedure times (>40â¯min). CONCLUSION: The individual analyses delivered plausible results, which support the validity of the ANP. The ANP may also be used for assessment of postoperative discomfort and patient satisfaction in the setting of outpatient surgery. In view of the short time interval between the two measurement points, the ANP for outpatients could in future be reduced to a single postoperative questionnaire.
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Procedimientos Quirúrgicos Ambulatorios , Propofol , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pacientes Ambulatorios , Dolor Postoperatorio , Náusea y Vómito Posoperatorios/epidemiología , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Since the publication of the first german guidelines on airway management in 2014, new techniques have been established in the clinical routine and new insights into existing strategies have been published. As a consequence the new guidelines on airway management of the German Society of Anesthesiology and Intensive Care Medicine represent the current state of scientific knowledge and integrate the currently recommended techniques and strategies. The aim of these guidelines is to guarantee an optimal care of patients undergoing anesthesiological procedures and serve as an orientation and decision aid for users.
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Manejo de la Vía Aérea/normas , Anestesiología/normas , Extubación Traqueal/efectos adversos , Extubación Traqueal/normas , Manejo de la Vía Aérea/efectos adversos , Algoritmos , Anestesia/normas , Humanos , Máscaras Laríngeas , Valor Predictivo de las PruebasRESUMEN
Since the publication of the first German guidelines on airway management in 2004 new techniques have been established in the clinical routine and new insights into existing strategies have been published. As a consequence the new guidelines on airway management of the German Society of Anesthesiology and Intensive Care Medicine represent the current state of scientific knowledge and integrate the currently recommended techniques and strategies. The aim of these guidelines is to guarantee an optimal care of patients undergoing anesthesiological procedures and serve as an orientation and decision aid for users.
Asunto(s)
Manejo de la Vía Aérea/normas , Extubación Traqueal , Manejo de la Vía Aérea/métodos , Anestesia , Anestesiología/normas , Cuidados Críticos/normas , Alemania , Adhesión a Directriz , Humanos , Intubación IntratraquealRESUMEN
BACKGROUND: Recently, indirect videolaryngoscopes have become increasingly important devices in difficult airway management. The aim of the present study was to investigate laryngoscopic view and intubation success using the new C-MAC® D-Blade in comparison to the established GlideScope® videolaryngoscope and conventional direct laryngoscopy in a randomized controlled trial. METHODS: Ninety-six adult patients with expected difficult airways undergoing elective ear, nose and throat surgery (ENT) requiring general anesthesia were investigated. Repeated laryngoscopy was performed using a conventional direct Macintosh laryngoscope (DL), C-MAC D-Blade (DB) and GlideScope (GS) in a randomized sequence before patients were intubated with the last device used. RESULTS: Both videolaryngoscopes showed significantly better C/L (Cormack-Lehane) classes than DL. Insufficient laryngoscopic view, defined as C/L ≥ III, was experienced in 18 patients (19.2%) with DL, in two patients with GS (2.1%) and in none with DB (0%). Time to best achievable laryngoscopic view did not differ between devices. Intubation time was significantly longer with both videolaryngoscopes (Median [Range] DB: 18 [8-33] s, and GS: 19 [9-34] s) than with DL (11 [5-26] s). However, intubation success was 100% for both DB and GS, whereas four patients could not be intubated using conventional direct laryngoscopy. CONCLUSION: Compared to direct Macintosh laryngoscopy, both C-MAC® D-Blade and GlideScope® comparably resulted in an improved view of the glottic opening with successful tracheal intubation in all patients.
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Manejo de la Vía Aérea/instrumentación , Manejo de la Vía Aérea/métodos , Intubación Intratraqueal/instrumentación , Intubación Intratraqueal/métodos , Laringoscopios , Laringoscopía/instrumentación , Adulto , Anciano , Femenino , Glotis/anatomía & histología , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Otorrinolaringológicos/instrumentación , Grabación en VideoRESUMEN
We enrolled 114 patients, aged 65-83 years, undergoing elective surgery (duration > 2h) into a randomised, controlled study to evaluate the performance of bispectral index and spectral entropy for monitoring depth of xenon versus propofol anaesthesia. In the propofol group, bispectral index and state entropy values were comparable. In the xenon group, bispectral index values resembled those in the propofol group, but spectral entropy levels were significantly lower. Mean arterial blood pressure was higher and heart rate was lower in the xenon group than in the propofol group. Bispectral index and spectral entropy considerably diverged during xenon but not during propofol anaesthesia. We therefore conclude that these measures are not interchangeable for the assessment of depth of hypnosis and that bispectral index is likely to reflect actual depth of anaesthesia more precisely compared with spectral entropy.
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Anestésicos por Inhalación/farmacología , Anestésicos Intravenosos/farmacología , Electroencefalografía/efectos de los fármacos , Propofol/farmacología , Xenón/farmacología , Anciano , Anciano de 80 o más Años , Presión Sanguínea/efectos de los fármacos , Entropía , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Monitoreo Intraoperatorio/métodos , Estudios Prospectivos , Procesamiento de Señales Asistido por ComputadorRESUMEN
BACKGROUND: Previous studies in adult patients and animal models have demonstrated that pulse pressure variation (PPV) and stroke volume variation (SVV) can be used to predict the response to fluid administration. Currently, little information is available on the performance of these variables in infants and neonates. The aim of our study was to assess whether PPV and SVV can predict fluid responsiveness in an animal model and to investigate the influence of different tidal volumes applied. METHODS: PPV and SVV were monitored by pulse contour analysis in 19 anaesthetized and paralysed piglets during ventilation with tidal volumes (V(T)) of 5, 10 and 15 ml/kg both before and after fluid loading with 25 ml/kg of hydroxy-ethyl starch 6% (HES). Cardiac output was measured by pulmonary artery thermodilution and a positive response to HES infusion was defined as >/=20% increase in the stroke volume index (SVI). RESULTS: Before HES infusion, PPV and SVV were significantly greater during ventilation with a V(T) of 10 and 15 ml/kg than during ventilation with a V(T) of 5 ml/kg (P<0.05). After HES infusion, only ventilation with V(T) 15 ml/kg resulted in a significant increase in PPV and SVV. As assessed by receiver operating characteristic curve analysis, SVV during ventilation with V(T) 10 ml/kg was the best predictor of a positive response to fluid loading (AUC=0.87). CONCLUSIONS: In this paediatric animal model, we found that SVV during ventilation with 10 ml/kg was a sensitive and specific predictor of the response to fluid loading.
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Presión Sanguínea/fisiología , Fluidoterapia , Volumen Sistólico/fisiología , Animales , Animales Recién Nacidos , Protocolos Clínicos , Femenino , Masculino , Modelos Animales , Respiración Artificial , Pruebas de Función Respiratoria , Sensibilidad y Especificidad , Porcinos , Termodilución , Volumen de Ventilación Pulmonar/fisiologíaRESUMEN
BACKGROUND AND OBJECTIVES: The myocardial performance index is a non-geometric, heart rate-independent echocardiography-derived index of left ventricular performance combining systolic and diastolic function. There is an ongoing debate whether the myocardial performance index is affected by preload or not. Moreover, a systematic evaluation of the effect of changing tidal volume ventilation on the myocardial performance index is still lacking. The aim of our study was to assess whether acute changes in preload and/or different depth of tidal volume ventilation affect the myocardial performance index. METHODS: In all, 14 anesthetized pigs (35 +/- 2 kg) were studied during changing tidal volumes (VT 5, 10 and 15 mL kg(-1)) at baseline, after removal of 500 cm(3) of blood (haemorrhage) and after retransfusion of shed blood plus additional 500 cm(3) 6% hydroxyethyl starch (fluid loading). Echocardiographic measurements at each experimental stage included myocardial performance index, left ventricular end-diastolic area and fractional area change. Central venous pressure, pulmonary capillary wedge pressure, cardiac output and stroke volume index were obtained by a pulmonary artery catheter. Global end-diastolic volume was obtained by transpulmonary thermodilution. RESULTS: Comparing different loading conditions, we found significant changes in cardiac output, stroke volume index, central venous pressure, pulmonary capillary wedge pressure, global end diastolic volume and left ventricular end-diastolic area, indicating clinically relevant changes in preload. In the haemorrhage group, there was a significant reduction in the myocardial performance index (P < 0.05) independent of tidal volume applied and this was reversed after fluid loading. However, myocardial performance index was significantly impaired (P < 0.05) by high tidal volume ventilation (15 mL kg(-1)), while tidal volumes of 5 and 10 mL kg(-1) had no effect. CONCLUSIONS: The myocardial performance index is largely dependent on changes in preload. Moreover, high tidal volume ventilation significantly impaired the myocardial performance index.
Asunto(s)
Ecocardiografía Doppler/métodos , Fluidoterapia/métodos , Fluidoterapia/estadística & datos numéricos , Corazón/fisiopatología , Respiración Artificial/métodos , Volumen de Ventilación Pulmonar , Animales , Apnea/fisiopatología , Apnea/terapia , Presión Sanguínea/efectos de los fármacos , Transfusión Sanguínea , Gasto Cardíaco/efectos de los fármacos , Modelos Animales de Enfermedad , Femenino , Corazón/efectos de los fármacos , Frecuencia Cardíaca/efectos de los fármacos , Hemorragia/fisiopatología , Derivados de Hidroxietil Almidón/administración & dosificación , Masculino , Monitoreo Fisiológico/estadística & datos numéricos , Sustitutos del Plasma/administración & dosificación , Volumen Sistólico/efectos de los fármacos , Porcinos , Termodilución , Volumen de Ventilación Pulmonar/efectos de los fármacos , Factores de Tiempo , Disfunción Ventricular IzquierdaRESUMEN
BACKGROUND: Intracerebral microdialysis is a sensitive tool to analyse tissue biochemistry, but the value of this technique to monitor cerebral metabolism during systemic haemorrhage is unknown. The present study was designed to assess changes of intracerebral microdialysis parameters both during systemic haemorrhage and after initiation of therapy. METHODS: Following approval of the Animal Investigational Committee, 18 healthy pigs underwent a penetrating liver trauma. Following haemodynamic decompensation, all animals received a hypertonic-hyperoncotic solution and either norepinephrine or arginine vasopressin, and bleeding was subsequently controlled. Extracellular cerebral concentrations of glucose (Glu), lactate (La), glycerol (Gly), and the lactate/pyruvate ratio (La/Py ratio) were assessed by microdialysis. Cerebral venous protein S-100B was determined. Haemodynamic data, blood gases, S-100B, and microdialysis variables were determined at baseline, at haemodynamic decompensation, and repeated after drug administration. RESULTS: Microdialysis measurements showed an increase of La, Gly, and La/Py ratio at BL Th compared to BL (mean +/- SEM; La 2.4 +/- 0.2 vs. 1.4 +/- 0.2 mmol x l(-1), p < 0.01; Gly 37 +/- 7 vs. 27 +/- 6 micromol x l(-1), n.s.; La/Py ratio 50 +/- 8 vs. 30 +/- 4, p < 0.01), followed by a further increase during the therapy phase (La 3.4 +/- 0.3 mmol x l(-1); Gly 69 +/- 10 micromol x l(-1); La/Py ratio 58 +/- 8; p < 0.001, respectively). Cerebral venous protein S-100B increased at decompensation and after therapy, but decreased close to baseline values after 90 min of therapy. CONCLUSIONS: In this model of systemic haemorrhage, changes of cerebral energy metabolism detected by intracerebral microdialysis indicated anaerobic glycolysis and degradation of cellular membranes throughout the study period.
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Química Encefálica/fisiología , Encéfalo/fisiopatología , Metabolismo Energético/fisiología , Hemorragia/fisiopatología , Hipoxia-Isquemia Encefálica/fisiopatología , Microdiálisis/métodos , Animales , Encéfalo/metabolismo , Circulación Cerebrovascular/fisiología , Modelos Animales de Enfermedad , Líquido Extracelular/química , Líquido Extracelular/metabolismo , Femenino , Glucosa/metabolismo , Glicerol/metabolismo , Glucólisis/fisiología , Hemorragia/complicaciones , Hipoxia-Isquemia Encefálica/diagnóstico , Hipoxia-Isquemia Encefálica/etiología , Ácido Láctico/metabolismo , Masculino , Proteínas de la Membrana/análisis , Proteínas de la Membrana/metabolismo , Microdiálisis/normas , Monitoreo Fisiológico/métodos , Monitoreo Fisiológico/normas , Factores de Crecimiento Nervioso/análisis , Factores de Crecimiento Nervioso/sangre , Subunidad beta de la Proteína de Unión al Calcio S100 , Proteínas S100/análisis , Proteínas S100/sangre , Choque/complicaciones , Choque/fisiopatología , Sus scrofaRESUMEN
BACKGROUND: Previous studies have shown that stroke volume variation (SVV) may be used to assess preload and fluid responsiveness. It is currently under debate, if SVV reliably displays changes in preload during ventilation with clinically used tidal volumes. This study was designed to evaluate whether the predictive value of SVV depends on the tidal volume applied particularly during acute changes of preload. METHODS: We studied 14 anesthetized pigs (35 +/- 2 kg) during changing tidal volumes (5, 10 and 15 ml/kg) at normovolemia (BL), after removal of 500 cc of blood (Hypo) and after retransfusion plus additional 500 cc 6% hydroxyethyl starch (Hyper). SVV was recorded continuously, and global end-diastolic volume (GEDV) was obtained by transpulmonary thermodilution at each experimental stage. RESULTS: GEDV changed significantly comparing the different experimental stages (P < 0.0001). During ventilation with 5 ml/kg, SVV did not change significantly at the different loading conditions. In contrast, during ventilation with both 10 and 15 ml/kg, SVV changed significantly comparing hemorrhage to fluid loading. However, at 15 ml/kg SVV was above the recommended value throughout the experiment. CONCLUSIONS: In this animal model, SVV was not sensitive to acute changes in preload during ventilation with a tidal volume of 5 ml/kg. Moreover, ventilation with high tidal volume may suggest volume loading even after sufficient volume resuscitation.
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Fluidoterapia/efectos adversos , Hemorragia/fisiopatología , Volumen Sistólico/fisiología , Volumen de Ventilación Pulmonar/fisiología , Animales , Gasto Cardíaco/fisiología , Femenino , Masculino , Monitoreo Fisiológico/estadística & datos numéricos , Volumen Sistólico/efectos de los fármacos , Porcinos , Termodilución/métodosRESUMEN
BACKGROUND AND OBJECTIVE: This study was performed to compare three disposable airway devices, the LMA Unique (LMA-U), the Ambu laryngeal mask (Ambu LM) and the Soft Seal laryngeal mask (Soft Seal LM) for elective general anaesthesia during controlled ventilation in non-paralysed patients. METHODS: One hundred and twenty ASA I-III patients scheduled for routine minor obstetric surgery were randomly allocated to the LMA-U (n = 40), Ambu LM (n = 40) or Soft Seal LM (n = 40) groups, respectively. Patients were comparable with respect to weight and airway characteristics. A size 4 LMA was used in all patients and inserted by a single experienced anaesthesiologist. Oxygenation, overall success rate, insertion time, cuff pressure and resulting airway leak pressure were determined as well as a subjective assessment of handling and the incidence of sore throat, dysphagia and hoarseness. RESULTS: Time of insertion was shortest with the Ambu LM, while failure rates were comparable with the LMA-U, the Ambu LM and the Soft Seal LM (median 19 s; range 8-57 s; success rate 100% vs. 14; 8-35; 97% vs. 20; 12-46; 95%). Insertion was judged 'excellent' in 75% of patients in the LMA-U group, in 70% of patients in Ambu LM group and in 65% of patients in the Soft Seal LM group. There was no difference between devices with respect to postoperative airway morbidity at 6 h or 24 h following surgery. CONCLUSIONS: All three disposable devices were clinically suitable with respect to insertion times, success rates, oxygenation, airway and leak pressures, as well as to subjective handling and postoperative airway morbidity.
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Equipos Desechables , Máscaras Laríngeas , Procedimientos Quirúrgicos Obstétricos/métodos , Respiración Artificial/instrumentación , Presión del Aire , Anestesia General/métodos , Presión Sanguínea , Trastornos de Deglución/etiología , Electroencefalografía/métodos , Diseño de Equipo , Femenino , Frecuencia Cardíaca , Humanos , Máscaras Laríngeas/efectos adversos , Persona de Mediana Edad , Oxígeno , Faringitis/etiología , Estudios Prospectivos , Respiración Artificial/métodos , Factores de TiempoRESUMEN
Our aim was to assess the association between lower urinary tract symptoms (LUTS) and erectile dysfunction by means of International Prostate Symptom Score (IPSS) and Sexual Health Inventory for Men (SHIM) questionnaire. A total of 69 eligible patients who were admitted to our outpatient clinic with lower urinary tract symptoms were included in the study. A self administered questionnaire of IPSS and SHIM were given to patients. Demographics and medical history data were recorded. Any risk factor that may be associated with erectile dysfunction, including coronary artery disease, diabetes, hypertension, and smoking status, was determined in each patient. Correlation tests were used to examine the relationship between lower urinary tract symptoms and erectile dysfunction by controlling the effects of age and comorbidities. Mean age was 58.6 +/- 13.1 31-86 years. Mean SHIM and IPSS total score was 14.3 +/- 7.5 and 11.5 +/- 8.1, respectively. Spearman correlation coefficient between IPSS and SHIM scores was found to be -0.41. There was a significant negative correlation with IPSS total scores of moderate degree when both age and presence of risk factor was controlled (r = -0.31; p = 0.009). Storage symptom scores showed significant correlation with SHIM scores (r = -0.33; p = 0.000). The association between SHIM score and each item of IPSS showed significant correlation for urgency, straining and nocturia when age controlled. The degree of bother by LUTS as determined by the IPSS quality of life question was also correlated with SHIM scores; however, this correlation was not significant when age or risk factor for ED was controlled. The presence of LUTS especially storage symptoms is strongly associated with erectile dysfunction independent of age and comorbidities.
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Disfunción Eréctil/complicaciones , Hiperplasia Prostática/complicaciones , Trastornos Urinarios/complicaciones , Adulto , Anciano , Anciano de 80 o más Años , Disfunción Eréctil/patología , Disfunción Eréctil/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Pacientes Ambulatorios , Próstata/patología , Próstata/fisiopatología , Hiperplasia Prostática/patología , Hiperplasia Prostática/fisiopatología , Calidad de Vida , Encuestas y Cuestionarios , Trastornos Urinarios/patología , Trastornos Urinarios/fisiopatologíaRESUMEN
BACKGROUND AND OBJECTIVE: The present study was designed to compare cerebral oxygenation measured with near infrared spectroscopy and local brain tissue oxygen partial pressure, respectively, in pigs during cardiopulmonary resuscitation. Since tissue overlying the brain may have an impact on near infrared spectroscopy readings, we tested whether optode placement on intact skin or on the skull yielded comparable results. METHODS: Twelve healthy pigs were anaesthetized and subjected to continuous haemodynamic, near infrared spectroscopy and brain tissue oxygen partial pressure monitoring. After 4 min of untreated ventricular fibrillation, cardiopulmonary resuscitation was started and arginine vasopressin was administered repeatedly three times. Near infrared spectroscopy values recorded were both the tissue oxygenation index and the tissue haemoglobin index as well as relative changes of chromophores (haemoglobin and cytochrome oxidase). Four animals served as control and were measured with both near infrared spectroscopy optodes mounted on the intact skin of the forehead, while in the remaining eight animals, one near infrared spectroscopy optode was implanted directly on the skull. RESULTS: Near infrared spectroscopy readings at the skin or at the skull differed consistently throughout the study period. After arginine vasopressin administration, near infrared spectroscopy values at the different locations showed a transient dissociation. In contrast to near infrared spectroscopy measured on intact skin, near infrared spectroscopy readings obtained from skull showed a significant correlation to brain tissue oxygen partial pressure values (r = 0.67, P < 0.001). CONCLUSION: Near infrared spectroscopy readings obtained from skin and skull differed largely after vasopressor administration. Near infrared spectroscopy optode placement therefore may have an important influence on the tissue region investigated.
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Encéfalo/metabolismo , Reanimación Cardiopulmonar/métodos , Circulación Cerebrovascular/fisiología , Oxígeno/metabolismo , Espectroscopía Infrarroja Corta/métodos , Animales , Arginina Vasopresina/administración & dosificación , Presión Sanguínea/fisiología , Encéfalo/irrigación sanguínea , Complejo IV de Transporte de Electrones/metabolismo , Hemoglobinas/metabolismo , Modelos Animales , Monitoreo Fisiológico/métodos , Presión Parcial , Piel/metabolismo , Cráneo/metabolismo , Porcinos , Factores de Tiempo , Vasoconstrictores/administración & dosificaciónRESUMEN
BACKGROUND: As xenon anaesthesia (XE) does not produce haemodynamic depression its use may be of benefit in patients at high risk of intraoperative haemodynamic instability and perioperative cardiac complications. XE (n=22) was compared with total i.v. anaesthesia (TIVA, n=22) for differences in autonomic regulation, peri- and postoperative performance. METHODS: Patients undergoing abdominal aortic surgery were studied at five events: T1: baseline awake; T2: anaesthesia induction; T3: before aortic cross-clamping; T4: after aortic cross-clamping; T5: after aortic declamping. T3-T5: end-tidal xenon concentration 60 (5)%. Intraoperative analysis: heart rate, heart rate variability, blood pressure and cardiac output. Postoperative analysis: 24 h Holter ECG, intensive care unit and hospital stay, and patient's outcome after 6 months. RESULTS: XE in contrast to TIVA increased parasympathetic and decreased sympathetic activity. Median low to high frequency decreased significantly in the XE group after start of XE (P<0.05) and remained significantly lower during all events after start of XE as compared with TIVA (P=0.0001). After start of XE heart rate of these patients was significantly lower as compared with TIVA (P=0.04). Cardiac output increased significantly in TIVA after aortic declamping (P<0.05). Outcome parameters did not differ significantly between groups. CONCLUSIONS: XE patients demonstrated lower sympathetic and higher parasympathetic activity as compared with TIVA patients. This was reflected by significant differences in haemodynamics but did not correlate with a better postoperative outcome. Thus, it remains controversial whether XE provides benefits in high risk patients.
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Anestésicos por Inhalación/farmacología , Aorta Abdominal/cirugía , Sistema Nervioso Autónomo/efectos de los fármacos , Xenón/farmacología , Anciano , Anciano de 80 o más Años , Anestésicos Intravenosos/farmacología , Sistema Nervioso Autónomo/fisiopatología , Enfermedades Cardiovasculares/etiología , Electrocardiografía/efectos de los fármacos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Humanos , Periodo Intraoperatorio , Tiempo de Internación , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Propofol/farmacología , Factores de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND AND OBJECTIVE: The aim of the present study was to investigate the impact of arginine vasopressin (AVP), a drug currently under investigation for use during cardiopulmonary resuscitation, on cerebral oxygenation and cerebral blood volume (CBV) in pigs with intact systemic circulation using near infrared spectroscopy. METHODS: Nine healthy pigs were anaesthetized and subjected to invasive haemodynamic monitoring as well as to non-invasive determination (with near infrared spectroscopy) of changes in the Tissue Oxygenation Index (TOI is the ratio of oxygenated to total tissue haemoglobin), Tissue Haemoglobin Index (THI, representing CBV) and cytochrome oxidase (deltaCytOx, representing the balance of intracellular oxygen supply). RESULTS: At both 3 and 5 min after AVP administration, TOI, THI and deltaCytOx were significantly (P < 0.001) reduced compared to baseline, while cerebral perfusion pressure increased significantly (P < 0.001). The effects of AVP on TOI and THI lasted longer than on deltaCytOx. There were no significant changes with respect to the intracranial pressure throughout the study period. CONCLUSIONS: No improvement of cerebral oxygenation was detected after AVP administration in swine with an intact systemic circulation. In contrast to recently published investigations, AVP provoked a sustained drop in indices of cerebral oxygenation and CBV.
Asunto(s)
Arginina Vasopresina/farmacología , Volumen Sanguíneo/efectos de los fármacos , Química Encefálica/efectos de los fármacos , Circulación Cerebrovascular/efectos de los fármacos , Consumo de Oxígeno/efectos de los fármacos , Vasoconstrictores/farmacología , Animales , Complejo IV de Transporte de Electrones/metabolismo , Hematócrito , Hemodinámica/efectos de los fármacos , Presión Intracraneal/efectos de los fármacos , Espectroscopía Infrarroja Corta , PorcinosRESUMEN
BACKGROUND: Brain tissue oxygen pressure (PbtO2) correlates to cerebral blood flow (CBF) during spontaneous circulation, with one important regulator being nitric oxide (NO). Although it is established that arginine vasopressin (AVP) improves CBF and global cerebral oxygenation during cardiopulmonary resuscitation, it is unknown whether similar beneficial effects are present during spontaneous circulation. The purpose of this study was to investigate the effects of AVP with and without pre-treatment with the NO synthase inhibitor N-omega-nitro-L-arginine methyl ester (L-NAME) on local brain tissue oxygenation in a beating heart model. METHODS: Following approval of the Animal Investigational Committee, nine healthy piglets underwent general anaesthesia, and were instrumented with a probe in the cerebral cortex to measure PbtO2. Each animal was assigned to receive AVP (0.4 U . kg(-1)), and after a wash-out period, L-NAME (25 mg x kg(-1) over 20 min) followed by AVP (0.4 U x kg(-1)). After each AVP administration, nitroglycerine (25 microg x kg(-1) over 1 min) as a NO donor was infused to test the vascular reactivity independently from NOS inhibition. FINDINGS: Three minutes after administration of AVP, PbtO2 increased significantly (P < .05; mean +/- SEM, 31 +/- 11 versus 43 +/- 14 mm Hg, +39%), compared with baseline. After pre-treatment with L-NAME, the changes of PbtO2 after AVP were not significant (32 +/- 11 versus 28 +/- 10, -13%) when compared with the baseline. CONCLUSION: In this beating heart porcine model, local brain tissue oxygenation was improved after AVP alone, but not after inhibition of NO synthesis with L-NAME.