[Current guidelines on the care of tunelized vascular catheters in patients on home parenteral nutrition]. / Péce o tunelizované zilní katétry u nemocných na domácí parenterální výzive podle soucasných doporucení

Home parenteral nutrition is the only option to provide nutrition in a number of patients. Care of venous entry, its management and treatment of complications resulting from its use importantly affect patient survival. Appropriate care of the catheter and the use of current knowledge may prolong the lifespan of the catheter, reduce patient morbidity and mortality and thus increase quality of life of patients who are dependent on home parenteral nutrition. The present paper summarizes recommendations for the care of long-term venous catheters.

Physiological profiles of male and female taekwon-do (ITF) black belts.

Baseline physiological and kinanthropometric data were collected for 11 male and 12 female elite taekwon-do athletes from the Czech national team for evaluation of anthropometry, aerobic and anaerobic capacities, strength, visual reaction time, pulmonary function, flexibility and explosive power of the lower limbs (vertical jump). Both male and female taekwon-do black belts demonstrated low adiposity (8.2 and 15.4% fat, BMI 21.9 and 22.0 kg m(-2), respectively), normal reactivity and pulmonary function, above average muscular strength, PWC-170 (3.4 vs 2.7 W kg(-1)) and aerobic power (54 vs 42 ml min(-1) kg(-1)), and a high flexibility (37 and 38 cm) and anaerobic performance (peak power output from a 30 s Wingate test=14.7 and 10.1 W kg(-1); anaerobic capacity=334 and 242 J kg(-1), in males and females, respectively). In male athletes, competitive performance was significantly related to maximum power output and upper limb reaction time only, whereas in females, performance was related to maximum power output and ventilatory threshold level. These variables accounted for 66 and 67% of the performance rank in males and females, respectively. Time-motion analysis of competition taekwon-do fighting (two times 2 min) revealed 3-5 s bouts of maximum exercise alternating with low-intensity periods. This elicits high heart rates (100% HRmax) and lactate responses (11.4 mmol l(-1) = 81% LAmax), which agrees well with the physiological characteristics of taekwon-do black belts measured in laboratory exercise tests.

Energy cost of treadmill walking.

BACKGROUND: The purpose of this study was to determine if energy cost of walking (VO2) could be accurately predicted with the simple models which analyze relationship oxygen uptake-speed of walking. A model to predict energy cost of treadmill walking was published firstly 29 years ago. METHODS: Employing the new modification of this model from 1986 to analyze VO2-speed of walking relationship leads to the elaboration of a simple linear model, two-compartment linear model, polynomial model of second order and monoexponential model of the metabolic cost of treadmill walking. To verify and compare these models 87 males, age ranged from 19 to 62 years, were evaluated on a motor driven treadmill. They walked at 0% grade at various velocities ranged from 3 to 12 km.h-1. RESULTS: The linear model has in range of intensities 3-12 km.h-1 a form of VO2.kg-1 (ml.kg-1.min-1) = 5.228*v (km.h-1)-11.158, r = 0.812, S(EE) = 4.16 ml.kg-1.min-1. The two-compartment linear model has in range of intensities of 3-7 km.h-1 a form of VO2.kg-1 = 3.207*v(km.h-1)-1.777, r = 0.932, and S(EE) = 1.5. In the range of 7.1-12 km.VO2.kg-1 = 7.120*v-29.168, r = 0.901, S(EE) = 3.78. In the range of intensities from 3 to 12 km.h-1 a polynomial model was found in the form VO2.kg-1 = 4.501-0.108*v + 0.379*v2, r = 0.891, S(EE) = 4.43, and the exponential model had a form VO2.kg-1 = 4.360*exp(0.223*v), r = 0.861, S(EE) = 6.84. All these correlation coefficients were highly significant (p < 0.001 in all cases). CONCLUSIONS: It was concluded that when applied to adult population, the models provide reasonable estimate of the actual requirement for treadmill walking provided the subjects in a oxygen uptake steady-state. As other researches for VO2/step we have found U-shaped curves of coefficient energy cost of walking. The minimum was at speed about 4 km.h-1. This finding support the speculation that does exists the "optimal" speed of moving which reflects the minimal energy expenditure during the walking.

[Energy requirements for walking]. / Energetická nárocnost chuze.

The energy requirement of walking, expressed indirectly by the oxygen consumption per kg body weight was assessed during different speeds of walking on a treadmill within the range of 3-12 km.h-1 in 87 untrained healthy men aged 17.5 to 60 years. The dependence of VO2.kg-1 on the speed of walking is non-linear in the mentioned range. Most suitable is the two-component linear model which in the range of 3-7 km.h-1 has the shape of VO2.kg-1 (ml.kg-1.min-1 = 3.207.v/km.h-1 - 1.777, r = 0.932 with a mean predicting error of 1.5.ml.kg-1.min-1, in the range of load of 7-12 km.h-1 VO2 = 7.120.v - 29.168, r = 0.941 with a error predicting of 3.73. The polynomic model of relations in the entire range of 3-12 km.h-1 is VO2 = 4.503 - 0.108.v + 0.379.v2, r = 0.922 with a predicting error of 4.43 ml.kg-1.min-1, and finally the exponential model has the shape VO2 = 4.360 exp (0.223.v), r = 0.861 with a mean predicting error of 6.84 ml.kg-1.min-1 in the entire range of load intensities. The justification to express the relationship between the oxygen consumption and the rate of walking by a two-component linear model as well as by non-linear models is confirmed also by the high correlation coefficient (p < 0.001 in all instances). The error of assessment of VO2.kg-1 from the speed of walking is 10% or less in all models. The mentioned models, in particular the linear one, can be used for evaluation of physical activities involving walking outdoors.

[Use of walking in the evaluation of aerobic fitness]. / Vyuzití chuze k hodnocení aerobní zdatnosti.

The reliability and validity of assessment of the maximal oxygen consumption as a criterion of aerobic fitness by the 2000 m walking test was established in 38 students of the military secondary school (mean age 17.8 +/- 0.4 years). The reliability of the 2000 m walking test is very high, during repeated estimations in the course of one week we find a correlation coefficient of r = 0.82 (p < 0.001). There is also a close correlation of 2000 m walking time and 2000 m running time (r = 0.67, p < 0.001). A group of 18 students selected at random from the above group was examined in the laboratory on a treadmill up to vita maxima. A close correlation was found between the results during walking and the maximal oxygen consumption (VO2max.kg-1) (r = -0.59 and -0.60) and also the 2000 m running time and VO2max.kg-1 (r = 0.59), p < 0.01 in all instances. The standard error of the mean of the maximal oxygen consumption estimate from the 2000 m walk is 3.44 ml.kg-1 x min-1 (5.7%) and from the running time of the same distance 3.49 ml.kg-1 x min-1 (5.8%). These results justify the conclusion that the 2000 m rapid walking test (normal style) is a simple alternative way for estimating the maximal oxygen consumption and thus also for evaluating the level of aerobic fitness with an accuracy which matches that, when running is used for the test.