BACKGROUND: Muscle weakness is an important systemic consequence in adults with cystic fibrosis, but it can be challenging to evaluate clinically. This study examined the validity of lowerextremity functional tests to assess quadriceps muscle strength and muscle power. METHODS: The subjects underwent 4 functional tests: 30-s sit-to-stand test, stair-climb power test, vertical jump height, and triple hop distance. Quadriceps muscle strength and power were tested by using a dynamometer (the accepted standard). Quadriceps strength was measured from 5 maximum voluntary isometric contractions to obtain peak torque. Quadriceps power was evaluated from the peak power and peak velocity attained during isotonic contractions of the quadriceps at a preset load of 20% of the peak torque. Pearson correlations were used to determine associations between functional tests and accepted measures of quadriceps strength and power. RESULTS: Fifteen adults with cystic fibrosis (9 males; mean ؎ SD age, 32 ؎ 13 y; mean ؎ SD FEV 1 % predicted, 73 ؎ 19) completed the study. The stair-climb power test had the strongest correlations with peak torque (r ‫؍‬ 0.84, P < .001) and power (r ‫؍‬ 0.65, P ‫؍‬ .009). Vertical jump height was moderately correlated with quadriceps strength (r ‫؍‬ 0.62, P ‫؍‬ .014) and quadriceps peak power (r ‫؍‬ 0.51, P ‫؍‬ .048). Similarly, triple hop distance had moderate correlations with quadriceps strength (r ‫؍‬ 0.78, P ‫؍‬ .001) and peak power (r ‫؍‬ 0.57, P ‫؍‬ .026). The sit-to-stand test was only associated with quadriceps strength (r ‫؍‬ 0.55, P ‫؍‬ .034). CONCLUSIONS: Functional tests can be applied clinically to measure leg muscle strength and power, with the stair-climb power test having the strongest associations with the standard measures. The utility of using functional tests to evaluate longitudinal changes in muscle function and its association with clinical outcomes should be examined in cystic fibrosis.

This study evaluated the effects of intranasal phenylephrine, an alpha-adrenergic agonist used for respiratory congestion, on uteroplacental blood flow. Twelve subjects were recruited from the Women's Clinic. Inclusion criteria were age greater than 18 years, singleton gestation, absence of medical illness and gestational age of 22-38 weeks. Phenylephrine (0.2 ml of 1% aq. solution) was applied to each nostril. Maternal blood pressure and pulse, umbilical artery velocimetry, and fetal heart rate were recorded prior to drug administration and at 5, 15, 30, 45 and 60 min after administration. There were no significant changes in maternal pulse, blood pressure or fetal heart rate. All subjects had normal baseline umbilical artery Doppler systolic/diastolic ratios. Eleven of 12 subjects demonstrated an elevation of the systolic/diastolic ratio consistent with vasoconstriction following administration. This elevation reached statistical significance at 30 min. Significant individual variation existed with regards to timing of maximal excursion of the systolic/diastolic ratio. The mean maximal change of the systolic/diastolic ratio was 1.57 +/- 1.25 (p < 0.001) ranging from -0.53 to 4.11. The use of over-the-counter alpha-adrenergic agents may result in decreased umbilical artery flow velocities. In high-risk pregnancies these medications may be contraindicated.