RESUMEN
The kallikrein-kinin system has been investigated in many experimental models. Dysregulations of the KKS are likely to be involved in pathologies such as inflammation, cancer and cardiovascular diseases. Previous works on the human KKS mostly rely on gene polymorphism and mRNA expression. In order to assess the KKS in human at the protein level, we have developed an approach based on flow cytometric analysis of leukocytes. Whole blood samples were collected and erythrocytes were lysed. Permeabilised leukocytes were incubated with anti-B2R (IgG2b), anti-IgG2b-PE, anti-CD3-PerCP (lymphocytes) and anti-CD14-APC (monocytes) antibodies. FACScalibur analyzed fluorescence intensities. Results were expressed as per cent of B2R-positive cells in each leukocyte subset and as B2R fluorescence intensity per positive cell. Detection of the B2R protein by this methodology was validated by (i) correlation with Western blotting using two different B2R antibodies, (ii) BK-induced Erk activation, (iii) B2R mRNA expression. The methodology was then applied to evaluate variations of B2R expression in a population including young healthy, elderly healthy, and elderly treated hypertensive men and women. In the young healthy subjects, B2R distribution was: monocytes>polymorphonuclear neutrophils (PMN)>lymphocytes and no difference with gender was observed. Moreover, no difference was observed on PMN B2R expression. B2R expression remained unchanged in the elderly healthy or hypertensive men. By contrast, monocytes and lymphocytes B2R expressions were decreased in the elderly healthy women. Finally, FACS analysis of B2R expression on leukocytes subsets provides single cell quantification of B2R expression allowing comparison of cellular sub-populations. This approach provides a new efficient tool to investigate B2R profiling of immune system in pathological states.
Asunto(s)
Leucocitos/metabolismo , Receptor de Bradiquinina B2/metabolismo , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Western Blotting , Separación Celular , Femenino , Citometría de Flujo , Humanos , Hipertensión/tratamiento farmacológico , Hipertensión/metabolismo , Masculino , Microscopía Confocal , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptor de Bradiquinina B2/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
BACKGROUND: Aging and disease may make elderly patients particularly susceptible to hypotension during spinal anesthesia. However, the impact of small-dose bupivacaine on cerebral hemodynamics is not known. In this study, we assessed the effects of spinal anesthesia on cerebral blood flow (CBF) in very elderly patients. METHODS: We prospectively studied 20 patients aged >75 yr who underwent open surgical repair of a hip fracture and compared them with a control group of patients younger than 60 yr. Patients were placed in the lateral decubitus position to receive spinal anesthesia at L4-5 level. Noninvasive automated arterial blood pressure, heart rate, and transcranial Doppler measurements were recorded before spinal anesthesia (baseline = T0), 5 min after the end of local anesthetic injection (T1), 10 min after spinal anesthesia (T2), and in the postanesthesia care unit (T3). RESULTS: Systolic blood pressure significantly decreased at T1 (115 +/- 25 mm Hg) and T2 (114 +/- 24 mm Hg) compared with T0 (136 +/- 21 mm Hg) in the elderly group. Systolic and diastolic velocities significantly decreased compared to baseline values (at T1, T2). Significant modifications of the pulsatility index (PI) and resistance index occurred at T2 for PI and resistance index. No patient experienced an episode of bradycardia. Heart rate variations were not significantly different compared to T0. Neither hemodynamics nor cerebral effects were observed in the control group. CONCLUSION: In summary, spinal anesthesia results in a very small but statistically significant reduction of CBF velocity in very elderly patients.
Asunto(s)
Anestesia Raquidea , Anestésicos Locales/administración & dosificación , Bupivacaína/administración & dosificación , Circulación Cerebrovascular/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Arteria Cerebral Media/efectos de los fármacos , Factores de Edad , Anciano , Anciano de 80 o más Años , Velocidad del Flujo Sanguíneo/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Estudios de Casos y Controles , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Fracturas de Cadera/cirugía , Humanos , Hipotensión/fisiopatología , Flujometría por Láser-Doppler , Vértebras Lumbares , Masculino , Persona de Mediana Edad , Arteria Cerebral Media/fisiopatología , Estudios Prospectivos , Flujo Pulsátil/efectos de los fármacos , Ultrasonografía Doppler Transcraneal , Resistencia Vascular/efectos de los fármacosRESUMEN
BACKGROUND: Although it has been reported that an increase in skin temperature indicates block success with higher specificity and sensibility than skin sensitivity to pinprick and cold, the methodology previously used computer-assisted infrared thermography, a technique that is expensive and requires substantial personnel training. In this prospective observational study, we evaluated whether a simple infrared thermometer can reliably predict block effectiveness after infraclavicular brachial plexus blockade. METHODS: Thirty consecutive patients undergoing upper limb surgery under infraclavicular block were enrolled. From the end of the local anesthetic injection, skin temperature was measured in all four major nerve distribution areas, and the sensory block onset (using cold and pinprick with 0 = no sensation to 2 = normal) were evaluated every 5 min for 30 min. A successful block was defined as the absence of sensation to cold (swab soaked with alcohol) and pinprick (needle) with a score of "0" within 30 min after the injection in the 4 major nerve distribution areas (radial, ulnar, median and musculocutaneous). Skin temperature measurements were performed using a noncontact temperature probe. RESULTS: One-hundred-twenty nerves (30 patients, 4 nerves per patient) were anesthetized. Twenty-five patients had a successful block. Four patients required supplementation for block failure. General anesthesia was performed in one patient. Skin temperature variation was not different among different nerves. There was a statistically significant increase in cutaneous temperature after nerve block compared to the same skin area before the procedure (P < 0.0001 from T5 to T30). Average temperature variations in blocked versus unblocked nerves at the same time were significantly different (P < 0.05 at T5 then P < 0.0001 from T10 to T30). When temperature in a specific sensory territory increased 1 degree C or more, at 5 and 10 min, the specific nerve was blocked (the score was "0"). Thus, when temperature changes in all 4 nerves were noted at 5 and 10 min, the block was successful at 30 min. No change in temperature in the contralateral arm or in the core temperature was observed. CONCLUSION: Skin temperature assessment with an infrared thermometer is a reliable, simple and early indicator of a successful nerve block.
Asunto(s)
Plexo Braquial , Bloqueo Nervioso , Temperatura Cutánea/efectos de los fármacos , Anciano , Electrocardiografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Monitoreo Intraoperatorio , Tamaño de la Muestra , Termómetros , Extremidad Superior/cirugíaRESUMEN
BACKGROUND: Spinal anesthesia in elderly patients is frequently associated with significant technical difficulties. Thus, we compared the classical midline approach to the paramedian approach to perform continuous spinal anesthesia (CSA). METHODS: We prospectively studied 40 patients aged >75 yr who underwent open surgical repair of a hip fracture. These patients were randomly allocated to one of two groups: Group M: midline approach, and Group PM: paramedian approach. Patients were positioned in the lateral decubitus to receive CSA at L4-5 level. CSA was considered successful if cerebrospinal fluid was obtained through the needle. In case of initial failure in either approach, the same approach was repeated by the same operator. If two attempts were unsuccessful, the other anatomical approach was used by the same operator. If both approaches failed, a staff anesthesiologist performed a final attempt. In case of failure or insufficient block, the patient received general anesthesia. RESULTS: The success rate after the first attempt was 85% (17) for Group PM and 45% (9) for Group M (P = 0.02). All catheters were successfully introduced. No patient required general anesthesia. Vascular puncture after needle puncture was observed in six patients in Group M versus 0 in Group PM (P = 0.03), but none were of clinical consequence. No other clinically significant complications were observed. CONCLUSION: In summary, after the initial attempt, the paramedian approach is associated with an increased success rate, compared with the midline approach, during the performance of CSA in elderly patients.
Asunto(s)
Anestesia Raquidea/métodos , Factores de Edad , Anciano , Anciano de 80 o más Años , Femenino , Fracturas de Cadera/epidemiología , Fracturas de Cadera/cirugía , Humanos , Masculino , Estudios ProspectivosRESUMEN
BACKGROUND: In this prospective study we compared the success of the infraclavicular brachial plexus block using double-stimulation in regard to the second nerve response elicited with neurostimulation. METHODS: Six-hundred-twenty-eight patients undergoing emergency upper limb surgery using infraclavicular brachial plexus block were included in this study. The musculocutaneous nerve was initially blocked and the groups were then evaluated according to the second nerve located, which was radial in 54%, median in 35%, and ulnar in 11% of patients. Blocks were performed using lidocaine 1.5% with 1/400,000 epinephrine 40 mL in all cases. The block was assessed every 5 min for 30 min after completion of the block. RESULTS: The success rate was 96% for the radial response group, 89% for the median response group, and 90% for the ulnar response group (P < 0.05). Time to perform the block and the onset time were not significantly different among groups. No serious complications were observed. CONCLUSION: We conclude that having initially located and blocked the musculocutaneous nerve, subsequent injection on a radial response resulted in a slightly more reliable success rate than injection with an ulnar or median response.