ABSTRACT
OBJECTIVE: The purpose of this study was to evaluate the effects of electrical muscle stimulation (EMS) on muscles, using 99mTc-sestamibi SPECT/CT. MATERIALS AND METHODS: We prospectively enrolled 20 consecutive male professional water polo players. The mean age was 25 years (range, 18-36 years). All athletes underwent 99mTc-sestamibi SPECT/CT of the thigh (rectus femoris and vastus medialis muscle groups) before and after EMS. Images were quantified to identify increases in perfusion after EMS. RESULTS: Before EMS, there were no significant differences between the right and left thigh (rectus femoris and vastus medialis muscles) in terms of perfusion (p = 0.4). However, the comparison between the pre- and post-EMS analyses of the same muscle groups showed significant differences in radiotracer uptake (p < 0.001), with a mean increase in perfusion of 128% for the rectus femoris muscle group (95% CI: 0.86-1.61) and 118% for the vastus medialis muscle group (95% CI: 0.96-1.79). CONCLUSION: 99mTc-sestamibi SPECT/CT is an objective means of evaluating blood flow in muscles submitted to EMS, which appears to promote significant increases in such blood flow.
OBJETIVO: O objetivo deste estudo foi avaliar o efeito da estimulação elétrica transcutânea na musculatura esquelética utilizando-se SPECT/CT com 99mTc- sestamibi. MATERIAIS E MÉTODOS: Foram prospectivamente avaliados 20 atletas masculinos de polo aquático (18-36 anos de idade; média de 25 anos). Todos os atletas foram submetidos a SPECT/CT com 99mTc- sestamibi das coxas antes e após estimulação elétrica transcutânea dos grupos musculares reto femoral e vasto medial. As imagens foram quantificadas para identificar aumento da perfusão. RESULTADOS: A comparação da perfusão dos grupos musculares (reto femoral e vasto medial) direito versus esquerdo durante o repouso não demonstrou diferença significativa (p = 0,4). Entretanto, quando comparados esses mesmos grupos musculares antes e após a estimulação elétrica, observou-se diferença significativa na captação do traçador (p < 0,001), com aumento perfusional médio de 128% do grupo reto femoral (IC 95%: 0,86-1,61) e 118% do grupo vasto medial (IC 95%: 0,96-1,79) no grupo estimulado. CONCLUSÃO: A SPECT/CT com 99mTc- sestamibi é capaz de demonstrar de forma objetiva que a estimulação elétrica transcutânea aumenta significativamente o fluxo sanguíneo muscular.
ABSTRACT
Abstract Objective: The purpose of this study was to evaluate the effects of electrical muscle stimulation (EMS) on muscles, using 99mTc-sestamibi SPECT/CT. Materials and Methods: We prospectively enrolled 20 consecutive male professional water polo players. The mean age was 25 years (range, 18-36 years). All athletes underwent 99mTc-sestamibi SPECT/CT of the thigh (rectus femoris and vastus medialis muscle groups) before and after EMS. Images were quantified to identify increases in perfusion after EMS. Results: Before EMS, there were no significant differences between the right and left thigh (rectus femoris and vastus medialis muscles) in terms of perfusion (p = 0.4). However, the comparison between the pre- and post-EMS analyses of the same muscle groups showed significant differences in radiotracer uptake (p < 0.001), with a mean increase in perfusion of 128% for the rectus femoris muscle group (95% CI: 0.86-1.61) and 118% for the vastus medialis muscle group (95% CI: 0.96-1.79). Conclusion: 99mTc-sestamibi SPECT/CT is an objective means of evaluating blood flow in muscles submitted to EMS, which appears to promote significant increases in such blood flow.
Resumo Objetivo: O objetivo deste estudo foi avaliar o efeito da estimulação elétrica transcutânea na musculatura esquelética utilizando-se SPECT/CT com 99mTc- sestamibi. Materiais e Métodos: Foram prospectivamente avaliados 20 atletas masculinos de polo aquático (18-36 anos de idade; média de 25 anos). Todos os atletas foram submetidos a SPECT/CT com 99mTc- sestamibi das coxas antes e após estimulação elétrica transcutânea dos grupos musculares reto femoral e vasto medial. As imagens foram quantificadas para identificar aumento da perfusão. Resultados: A comparação da perfusão dos grupos musculares (reto femoral e vasto medial) direito versus esquerdo durante o repouso não demonstrou diferença significativa (p = 0,4). Entretanto, quando comparados esses mesmos grupos musculares antes e após a estimulação elétrica, observou-se diferença significativa na captação do traçador (p < 0,001), com aumento perfusional médio de 128% do grupo reto femoral (IC 95%: 0,86-1,61) e 118% do grupo vasto medial (IC 95%: 0,96-1,79) no grupo estimulado. Conclusão: A SPECT/CT com 99mTc- sestamibi é capaz de demonstrar de forma objetiva que a estimulação elétrica transcutânea aumenta significativamente o fluxo sanguíneo muscular.
ABSTRACT
PURPOSE: The purpose of the study is to improve our ability to detect catecholamine dependency and refractory septic shock. METHODS: Fifty-one patients with septic shock were studied within the first 4 hours of norepinephrine administration. Patients were divided into 2 groups according to their evolution in the intensive care unit, namely, group A, shock reversal, and group B, no shock reversal. Reversal of shock was defined as the maintenance of a systolic blood pressure greater than or equal to 90 mm Hg without vasopressor support for 24 hours or more. Vascular reactivity was tested using incremental doses of phenylephrine. Muscle tissue oxygen saturation and its changes during a vascular occlusion test were measured. RESULTS: Group B patients had a higher Sequential Organ Failure Assessment (SOFA) score and lactate level and more frequently received norepinephrine and renal replacement. Overall mortality was 100% in group B (16/16) and 20% (7/35) in group A. Phenylephrine increased mean arterial pressure in a dose-dependent manner more significantly in group A patients than in group B (P = .0004). Basal tissue oxygen saturation and the recovery slope after vascular occlusion test were lower in group B. In multivariate analysis, 4 parameters remained independently associated with mortality: the increase in mean arterial pressure at phenylephrine 6 µg/kg per minute, the recovery slope, SOFA score, and norepinephrine doses at H0. CONCLUSIONS: The intensity of septic shock-induced vascular hyporesponsiveness to vasopressor is tightly linked to septic shock severity and evolution and may potentially be identified early with simple to obtain parameters such as near-infrared spectroscopy value, SOFA score, or norepinephrine dose.
Subject(s)
Norepinephrine/therapeutic use , Shock, Septic/drug therapy , Vasoconstrictor Agents/therapeutic use , Adult , Aged , Blood Pressure/drug effects , Case-Control Studies , Dose-Response Relationship, Drug , Female , Humans , Intensive Care Units , Male , Middle Aged , Norepinephrine/administration & dosage , Organ Dysfunction Scores , Sensitivity and Specificity , Shock, Septic/mortality , Vascular Resistance/drug effects , Vasoconstrictor Agents/administration & dosage , Young AdultABSTRACT
Heart failure is a systemic disease in which both myocardium and skeletal muscle exhibit alterations of energy metabolism. Failing myocardium exhibits impaired utilization of free fatty acids and glucose, which are major substrates for myocardial energy production. Ketone bodies normally provide a modest contribution to energy balance, but serum concentrations of ketone bodies are elevated in heart failure. To profile ketone body metabolism in advanced heart failure, we directly measured ketone body utilization by heart and skeletal muscle.Metabolite concentrations in arterial, coronary sinus, and central venous beds were measured to derive myocardial and skeletal-muscle ketone body utilization in 11 patients with advanced heart failure and 10 healthy control subjects who were undergoing electrophysiologic procedures. As expected, the mean myocardial arteriovenous oxygen difference was significantly increased in the heart-failure patients (8.3 ± 0.4 mL/dL, vs 7 ± 0.5 mL/dL in the control subjects; P = 0.05). Although the mean myocardial ketone body extraction ratio was relatively unchanged (0.49 ± 0.05 in heart-failure patients vs 0.54 ± 0.06 in control subjects, P = 0.53), skeletal-muscle ketone body utilization was markedly lower in the heart-failure patients (0.18 ± 0.06, vs 0.4 ± 0.04 in control subjects; P = 0.01).In this preliminary study, heart failure was associated with tissue-specific alteration of ketone body metabolism. In advanced heart failure, skeletal-muscle ketone body utilization was impaired, whereas myocardial ketone body utilization was preserved. Future studies are needed to determine whether ketone body metabolism serves as a dynamic quantitative biomarker of skeletal myopathy and fatigue in heart failure.
