RESUMEN
PURPOSE: Orthostatic hypotension, leading to cerebral hypoperfusion, can result in postural instability and falls in older adults. We determined the efficacy of a novel, intermittent pneumatic compression system, applying pressure around the lower legs, as a countermeasure against orthostatic stress in older adults. METHODS: Data were collected from 13 adults (4 male) over 65 years of age. Non-invasive ultrasound measured middle cerebral artery blood velocity (MCAv) and finger photoplethysmography measured mean arterial blood pressure (MAP). Intermittent lower leg compression was applied in a peristaltic manner in the local diastolic phase of each cardiac cycle to optimize venous return during 1-min of seated rest and during a sit-to-stand transition to 1-min of quiet standing with compression initiated 15 s before transition. RESULTS: During seated rest, compression resulted in a 4.5 ± 6.5 mmHg increase in MAP, and 2.3 ± 2.1 cm/s increase in MCAv (p < 0.05). MAP and MCAv increased during the 15 s of applied compression before the posture transition (2.3 ± 7.2 mmHg and 2.1 ± 4.0 cm/s, respectively, p < 0.05) with main effects for both variables confirming continued benefit during the transition and quiet stand periods. CONCLUSIONS: Application of carefully timed, intermittent compression to the lower legs of older adults increased MAP and MCAv during seated rest and maintained an elevated MAP and MCAv during a transition to standing posture. Future research could assess the benefits of this technology for persons at risk for orthostatic hypotension on standing and while walking in an effort to reduce injurious, unexplained falls in older adults.
Asunto(s)
Circulación Cerebrovascular/fisiología , Pierna/irrigación sanguínea , Músculo Esquelético/irrigación sanguínea , Postura/fisiología , Anciano , Anciano de 80 o más Años , Velocidad del Flujo Sanguíneo , Femenino , Humanos , Masculino , Arteria Cerebral Media/fisiología , Músculo Esquelético/fisiología , Fotopletismografía , Flujo Sanguíneo Regional , Posición de PieRESUMEN
This study tested the hypothesis that intermittent compression of the lower limb would increase blood flow during exercise and postexercise recovery. Data were collected from 12 healthy individuals (8 men) who performed 3 min of standing plantar flexion exercise. The following three conditions were tested: no applied compression (NoComp), compression during the exercise period only (ExComp), and compression during 2 min of standing postexercise recovery. Doppler ultrasound was used to determine superficial femoral artery (SFA) blood flow responses. Mean arterial pressure (MAP) and cardiac stroke volume (SV) were assessed using finger photoplethysmography, with vascular conductance (VC) calculated as VC = SFA flow/MAP. Compared with the NoComp condition, compression resulted in increased MAP during exercise [+3.5 ± 4.1 mmHg (mean ± SD)] but not during postexercise recovery (+1.6 ± 5.9 mmHg). SV increased with compression during both exercise (+4.8 ± 5.1 ml) and recovery (+8.0 ± 6.6 ml) compared with NoComp. There was a greater increase in SFA flow with compression during exercise (+52.1 ± 57.2 ml/min) and during recovery (+58.6 ± 56.7 ml/min). VC immediately following exercise was also significantly greater in the ExComp condition compared with the NoComp condition (+0.57 ± 0.42 ml·min-1·mmHg-1), suggesting the observed increase in blood flow during exercise was in part because of changes in VC. Results from this study support the hypothesis that intermittent compression applied during exercise and recovery from exercise results in increased limb blood flow, potentially contributing to changes in exercise performance and recovery. NEW & NOTEWORTHY Blood flow to working skeletal muscle is achieved in part through the rhythmic actions of the skeletal muscle pump. This study demonstrated that the application of intermittent pneumatic compression during the diastolic phase of the cardiac cycle, to mimic the mechanical actions of the muscle pump, accentuates muscle blood flow during exercise and elevates blood flow during the postexercise recovery period. Intermittent compression during and after exercise might have implications for exercise performance and recovery.
Asunto(s)
Ejercicio Físico/fisiología , Aparatos de Compresión Neumática Intermitente , Pierna/irrigación sanguínea , Adulto , Diástole , Femenino , Voluntarios Sanos , Humanos , Masculino , Flujo Sanguíneo Regional , Adulto JovenRESUMEN
Difficulties with sleep and daytime sleepiness are common complaints among adults in the United States. During the past decade, the use of herbal preparations among adults increased from 2.5% to 12.4%. This article presents relevant aspects of the 1994 Dietary Supplements Health and Education Act that stimulated the proliferation of herbal medicinals and reviews the pharmacological properties of the most commonly available herbal wake-promoting and sedating products. Given the rapid increase in use of herbals, health care professionals need to educate themselves and their patients about the use of these preparations.
Asunto(s)
Enfermería Holística/métodos , Enfermeras Practicantes , Fitoterapia , Trastornos del Sueño-Vigilia/terapia , Sueño/efectos de los fármacos , HumanosRESUMEN
Binge-like alcohol exposure in neonatal rats on postnatal days 4 to 9 via artificial rearing results in a well-documented transient astrogliosis in the cerebral cortex. A recent study, which replicated the astrogliosis using artificial rearing, found that alcohol administered via daily exposure cycles in a vapor inhalation chamber on postnatal days 4 to 9 failed to elicit the effect, thus suggesting that the gliosis was an interactive effect of the artificial rearing administration and not specific to alcohol. The present study evaluated the effects in an intragastric intubation model that replicated the dosing parameters of the artificial rearing while avoiding the stress of surgery and extended maternal separation. In coronal frozen sections through parietal cortex labeled immunohistochemically for glial fibrillary acidic protein, the pups exposed to alcohol by intubation had a significantly greater density of glial fibrillary acidic protein-positive astrocytes per unit volume, compared with littermate controls intubated with a maltose-dextrin formula; alcohol also induced fibrillary hypertrophy of the labeled astrocytes. In the cerebellum, alcohol induced a significant reduction in Purkinje cell number as determined using the optical disector method. These outcomes extend previous findings that neonatal binge alcohol exposure induces acute cortical astrogliosis and Purkinje cell loss, and confirm that the alcohol-induced astrogliosis is not an artifact of artificial rearing.
Asunto(s)
Intoxicación Alcohólica/patología , Astrocitos/efectos de los fármacos , Corteza Cerebral/efectos de los fármacos , Etanol/toxicidad , Trastornos del Espectro Alcohólico Fetal/patología , Gliosis/patología , Degeneración Nerviosa/patología , Células de Purkinje/efectos de los fármacos , Animales , Animales Recién Nacidos , Astrocitos/patología , Recuento de Células , Corteza Cerebral/patología , Femenino , Proteína Ácida Fibrilar de la Glía/metabolismo , Masculino , Embarazo , Células de Purkinje/patología , Ratas , Ratas Sprague-DawleyRESUMEN
The two main objectives of this study were (1) to replicate previous findings that 6 days of binge-like exposure to alcohol during the neonatal brain growth spurt induces significant place learning deficits in juvenile rats and (2) to determine whether more limited (3-day) binge-like exposure during the neonatal period induces place learning deficits and whether the effects depend on the developmental timing of the exposure. Using artificial rearing methods and a split-litter experimental design, groups of male and female neonatal rats were given binge-like exposure to 4.5 g/kg/day of ethanol in milk formula either on Postnatal Days (PD) 4-6, PD 7-9, or PD 4-9, which yielded mean peak blood alcohol concentrations of 230-260 mg/dl. Controls included an artificially reared gastrostomy control group (GC) given an isocaloric milk formula diet on PD 4-9 and a suckle control group reared normally by lactating dams. Acquisition of place learning in the Morris spatial navigation task was trained for 6 consecutive days beginning on PD 26; a probe trial was given at the end of the sixth day. As expected, both males and females given alcohol on PD 4-9 had significant deficits in acquisition and probe trial performance relative to SC and GC groups. Males given the PD 7-9 exposure had significant place learning deficits which were as severe as with the full 6-day exposure. The PD 4-6 exposure in males produced only a nonsignificant trend toward slower acquisition. Females were not significantly affected by either 3-day exposure. The latter phase of the neonatal brain growth spurt appears to constitute a sex-specific period of enhanced vulnerability to alcohol-induced developmental spatial learning deficits.