Inferior vena cava ultrasonography before general anesthesia cannot predict arterial hypotension in patients undergoing vascular surgery.

INTRODUCTION: Intraoperative hypotension (IH) is an independent predictor of mortality. Some experts have suggested that ultrasound measurement of the inferior vena cava (IVC) in spontaneous ventilation can predict IH. OBJECTIVE: To evaluate the capacity of ultrasound measures of IVC in spontaneous ventilation to predict episodes of IH after anaesthesia induction. PATIENTS AND METHODS: We studied 55 high-risk cardiac patients undergoing vascular surgery. The maximum (dIVCmax) and minimum (dIVCmin) diameter of the IVC were measured and the collapsibility index CI = (dIVCmax-dIVCmin)/dIVCmax was calculated prior to anaesthesia induction. Three definitions of IH were used: systolic blood pressure (SBP) less than 100 mmHg, mean arterial pressure (MAP) less than 60 mmHg, and a decrease in MAP greater than or equal to 30% compared to baseline. RESULTS: There were no significant differences in dIVCmax or in CI between patients presenting IH after anaesthesia induction and those who did not. ROC curves for dIVCmax showed an area under the curve of 0.55 (0.39-0.70), 0.69 (0.48-0.90), and 0.57 (0.42-0.73) and ROC curves for the CI were 0.62 (0.47-0.78), 0.60 (0.41-0.78) and 0.62 (0.47-0.78) for the 3 definitions of IH (<100 mmHg, MAP < 60 mmHg, and MAP ≥30% baseline), respectively. CONCLUSIONS: Ultrasound measurements of IVC in spontaneous ventilation are not good predictors of IH after anaesthesia induction in these patients. The optimal cut-off points show low specificity and moderate sensitivity for predicting IH.

Anestesia regional periférica para revascularización arterial de miembros inferiores. Revisión bibliográfica y casos clínicos / Peripheral regional anesthesia for arterial revascularization of lower limbs. Bibliographical review and clinical cases

Introducción: La tendencia actual es diferir la cirugía de revascularización de miembros inferiores hasta etapas avanzadas, lo que explica que sean pacientes de mayor complejidad con alta morbimortalidad cardíaca y respiratoria. Los mayores avances para reducirlas, se han desarrollado en la preparación de los pacientes y en las técnicas quirúrgicas. La elección de la técnica anestésica no ha sido considerada un factor determinante. Los bloqueos regionales presentan potenciales ventajas, como mayor estabilidad hemodinámica y respiratoria. Objetivo: Realizar una revisión bibliográfica y presentación de casos clínicos sobre la utilidad de los bloqueos periféricos para anestesia en la cirugía de revascularización de miembros inferiores. Material y métodos: La búsqueda se realizó a través de la base de datos Medline, LILACS y SciELO. Se incluyeron estudios donde los bloqueos periféricos se utilizaron para anestesia. Se describen dos casos clínicos. Resultados: Se seleccionaron 4 artículos originales, 3 de ellos eran estudios descriptivos de la técnica y el cuarto una comparación con anestesia general inhalatoria. 2más correspondieron a casos clínicos. Conclusiones: No existe evidencia suficiente que permita concluir que reducen la mortalidad o la morbilidad cuando se la compara con las demás técnicas anestésicas. Esto puede ser debido al diseño metodológico de los estudios, a la no utilización de la ecografía como guía y la no sistematización de los bloqueos. El análisis de los casos clínicos sugiere que en situaciones específicas como pacientes de alto riesgo cardíaco y respiratorio, bajo tratamiento con anticoagulantes y antiagregantes estos presentan ventajas sobre las otras técnicas.

Background: The current trend is to defer revascularization surgery from lower limbs to advanced stages, which explains why they are more complex patients with high cardiac and respiratory mortality. The choice of anesthetic technique remains controversial. Regional blockades have potential advantages, such as hemodynamic and respiratory stability. Our primary objective was a bibliographic review to assess the peripheral blockages for anesthesia in lower limb revascularization surgery. Our secondary objective was report two clinical cases. Material and methods: The search was performed through the Medline, LILACS and SciELO database. We included studies where peripheral blocks were used for anesthesia. Two clinical cases are described. Results: Four original articles were selected, 3 of which were descriptive studies of the technique and the fourth a comparison with general inhalation anesthesia. 2 more corresponded to clinical cases. Conclusions: There is insufficient evidence to conclude that peripheral nerve block reduce mortality or morbidity when compared with other anesthetic techniques. This may be due to the methodological design of the studies, to the non-use of echocardiography as a guide and the non-systematization of the blocks. The analysis of the clinical cases suggests that this technique is a good option in specific situations as patients with high cardiac and respiratory risk, under treatment with anticoagulants and antiplatelets drugs.

Microcirculatory changes during cardiac surgery with cardiopulmonary bypass. / Alteraciones microcirculatorias en cirugía cardíaca con circulación extracorpórea.

OBJECTIVE: To evaluate microcirculation in intermediate and high mortality risk patients undergoing cardiac surgery (CS) with cardiopulmonary bypass (CPB). PATIENTS AND METHODS: The study included 22 patients with a Euroscore >3. Using the Videomicroscopy Side Stream Dark Field system, and evaluation was made of, capillary density, proportion of perfused capillaries, density of perfused capillaries, microcirculatory flow index (MFI), and heterogeneity flow index. Three to five video sequences were recorded: after induction of anaesthesia (T1), at the beginning of the CPB (T2), before finalising CPB (T3), at the end of the surgery, and before the patient was transferred to Intensive Care Unit (T4). Mean arterial pressure decreased, while the blood lactate increased significantly, when comparing the initial and final values (P<.05). MFI increased significantly in T3 and T4 (P<.05) with regards to the initial values. When the patients with and without postoperative complications were compared, significant differences were found in, Euroscore, left ventricular ejection fraction, and MFI in T3. CONCLUSIONS: in patients with intermediate/high preoperative risk, CS and CBP can involve an increase in MFI and blood lactate at the end of the study. These alterations suggest the possibility of a functional microcirculatory shunt at tissue perfusion level, secondary to the surgical injury and the CPB. Further investigation is needed to have a better understanding of the mechanisms involved.

Contribution of the coronary sinus blood to the pulmonary artery oxygen saturation gradient in cardiac surgery patients.

BACKGROUND: The coronary sinus oxygen saturation (SO2) can affect the oxygen saturation of the superior vena cava (superior cava SO2) and the pulmonary artery (pulmonary artery SO2), causing a gradient between the latter two (ΔSO2), as has been observed in different physiological and pathological conditions. The objective of the study was to evaluate the different determinants of ΔSO2 in cardiac surgery patients. METHODS: An observational, prospective study was carried out on 18 patients undergoing elective cardiac surgery. Blood samples were obtained from the superior vena cava, the pulmonary artery, the inferior vena cava, and the coronary sinus before extracorporeal circulation. RESULTS: The following measurements were made: superior cava SO2, pulmonary artery SO2, coronary sinus SO2, and inferior cava SO2. The mean values (± SD) were as follows: superior cava SO2=76.4±12.6%; inferior cava SO2=72.7±15.8%; coronary sinus SO2=46.6±17.0%; and pulmonary artery SO2=71.9±12.9%. The ΔSO2 was 4.5±5.5%. The average oxygen saturation (SO2avg=[Superior cava SO2 + inferior cava SO2]/2) was 74.6±13.7%. The superior cava SO2 was significantly higher than the pulmonary artery SO2, and the ΔSO2 was significantly different from zero (P≤0.05). No significant differences were found between the superior cava SO2 and the inferior cava SO2, and both were significantly different from the coronary sinus SO2. The difference between SO2avg and the pulmonary artery SO2 was 2.74±4.4%. CONCLUSION: The observed ΔSO2 could only be explained by dilution of the superior cava SO2 with blood with a lower SO2. The coronary sinus blood contributed to generate this gradient.

Effect of potassium sorbate and pH on the survival of Staphylococcus aureus in saturated sugar solutions.

Addition of 0.3% (w/w) of potassium sorbate (a permitted food additive) coupled with a reduction of pH from 7 to 6 or 5.5, resulted in a dramatic decrease in the survival of two S. aureus strains inoculated (10(8) c.f.u./ml) in laboratory media supplemented with sugar (227 g sugar/100 g water) and incubated at 35 degrees C. These in vitro results may be of potential value to improve the efficacy of sugar therapy for the treatment of certain infected wounds; however, clinical trials are needed to confirm these findings.

Effect of potassium sorbate and pH on the survival of Staphylococcus aureus in saturated sugar solutions

Addition of 0.3

(w/w) of potassium sorbate (a permitted food additive) coupled with a reduction of pH from 7 to 6 or 5.5, resulted in a dramatic decrease in the survival of two S. aureus strains inoculated (10(8) c.f.u./ml) in laboratory media supplemented with sugar (227 g sugar/100 g water) and incubated at 35 degrees C. These in vitro results may be of potential value to improve the efficacy of sugar therapy for the treatment of certain infected wounds; however, clinical trials are needed to confirm these findings.

Effect of potassium sorbate and pH on the survival of Staphylococcus aureus in saturated sugar solutions.

Addition of 0.3

(w/w) of potassium sorbate (a permitted food additive) coupled with a reduction of pH from 7 to 6 or 5.5, resulted in a dramatic decrease in the survival of two S. aureus strains inoculated (10(8) c.f.u./ml) in laboratory media supplemented with sugar (227 g sugar/100 g water) and incubated at 35 degrees C. These in vitro results may be of potential value to improve the efficacy of sugar therapy for the treatment of certain infected wounds; however, clinical trials are needed to confirm these findings.

Antiarthritic synergism of combined oral and parenteral chrysotherapy. II. Increased inhibition of activated leukocyte oxygen burst by combined gold action.

We have observed an antiarthritic effect of combined chrysotherapy in adjuvant arthritis. Since superoxide radicals (O2-) are potent mediators of rheumatoid inflammation, we studied the combined effect of auranofin (AF) and injectable golds on luminol-dependent chemiluminescence (LDCL) and O2- generation by cytochrome-c reduction of activated leukocytes by different receptor-mediated stimuli: phorbol myristic acetate, 10(-6) M; f-Met-Leu-Phe, 10(-6) M; and poly-L-histidine, 10(-5) M. AF, 0.6 and 0.9 micrograms Au/ml, inhibited 34 and 58% of O2- generation, respectively; the addition to AF of 0.3 micrograms Au/ml of gold thiosulfate (GTS) increased this inhibition to 84 and 97% of the oxygen burst. Similar synergistic potentiation inhibition was obtained by LDCL. When the inhibition of O2- generation by the combined action of AF and GTS was compared with AF + gold sodium thiomalate (GTM), only GTS showed an activation on AF's inhibition of the oxygen burst of human leukocytes. The ligand thiosulfate in equimolar concentrations to GTS had a statistically significant (P less than 0.01) inhibitory effect on AF's blockade of O2- generation during the first 5 min of the interaction with the PMNs; thiomalate had no effect. Sequential pretreatment of PMNs with AF and GTS on O2- generation revealed that for synergism of combined gold action to take place, the cell membrane had to be subjected first to the action of oral gold or to the simultaneous combined action of oral and parenteral gold.(ABSTRACT TRUNCATED AT 250 WORDS)

Antiarthritic synergism of combined oral and parenteral chrysotherapy. I. Studies in adjuvant-induced arthritis in rats.

In comparative clinical studies of auranofin (AF, oral gold) and parenteral gold in the treatment of rheumatoid arthritis, no difference in efficacy was detected. Since the pharmacologic profiles of these compounds are different, we studied their combined effect on adjuvant arthritis (AA). The effect of AF alone and combined with gold sodium thiomalate (GTM) or gold sodium thiosulfate (GTS) on the excretion of urinary hydroxyproline (UHP) and urinary calcium (UCa), and the articular index of arthritic rats was followed during five weeks of treatment. The excretion of UHP and UCa was significantly inhibited (P less than 0.005) in rats treated with AF combined with GTM or GTS as compared with animals treated with the individual gold compounds. However, the articular index only decreased significantly (P less than 0.02) in the group of rats treated with AF + GTS. The present studies open the possibility that combined treatment with oral and injectable gold provide a new approach for chrysotherapy with an increased antiarthritic potency.

Estudio multicentrico sobre la eficacia y tolerancia de una asociacion de metoprolol e hidroclorotiazida en el manejo de la hipertension arterial no complicada. / Multicenter study on the efficacy and tolerance of a combination of metoprolol and hydrochlorothiazide in the management of non complicated arterial hypertension

Ochocientos cincuenta y tres pacientes con hipertension leve o moderada fueron tratados en forma abierta por 85 medicos diferentes, bajo un protocolo comun, con una combinacion de 100 mg de metoprolol, un bloqueador selectivo de los receptores beta-1, y 12.5 mg de hidroclorotiazida, durante un periodo de 4 semanas. La presion arterial sistolica y diastolica descendio desde las dos primeras semanas, y la diferencia con respecto a los niveles previos fue estadisticamente significativa. La frecuencia cardiaca no se modifico significativamente. Doscientos sesenta y cinco pacientes fueron excluidos del analisis por abandonar la prueba o porque se infrigio el protocolo. En 412 pacientes (48.3%) se obtuvo un control completo de las cifras tensionales; en 112 (13.2%) el control fue solo parcial y en 64 (7.5%) la respuesta fue mala. Alrededor de 20% de los pacientes que terminaron la prueba tuvo uno o mas efectos indeseables, ninguno de los cuales fue grave. Los trastornos mas frecuentes fueron cefalea, mareo, fatiga, gastritis, nausea y vomito, y trastornos del sueno. Se concluyo que esta asociacion terapeutica es util en una buena proporcion de pacientes hipertensos y que sus efectos indeseables son, en general, de poca relevancia