Isokinetic muscle evaluation of quadriceps in patients with chronic obstructive pulmonary disease.

RATIONALE: Muscle debility has a significant impact on health-related quality of life in subjects with chronic obstructive pulmonary disease (COPD), and is correlated to exacerbation and even mortality. Assessing muscle strength is extremely relevant. Lack of standardisation in numbers of sets and rest interval in isokinetic test protocol can lead to distinct results, making com- prehension and comparisons among studies difficult. AIM: To analyse the effect of two sets and three different rest intervals on isokinetic strength measurement of quadriceps tests, in order to define the adequate test protocol. METHODS: Subjects with severe or very severe COPD underwent three isokinetic tests to evaluate knee extensor muscle strength, at an angular velocity of 60°â‹…s⁻¹, with rest intervals of 30, 60 and 120 seconds. Each test consisted of two sets of five repetitions, during which peak torque, total work and fatigue index were measured. RESULTS: In 20 studied subjects (66.1 ± 7.4 years, 70 ± 10.8 kg, 167.4 ± 6.2 cm, FEV1 36.5 ± 10.1%), there were no significant differences in peak torque, total work and fatigue index, independent of number of sets or rest interval between sets. CONCLUSION: In subjects with severe or very severe COPD, quadriceps muscle strength can be evaluated by an isokinetic protocol with one set of five repetitions. If two sets are performed, a rest interval of 30 seconds is enough to ensure muscle recovery between sets.

Pulmonary mechanic and lung histology injury induced by Crotalus durissus terrificus snake venom.

In the present work we investigated the effects of Crotalus durissus terrificus venom (CdtV) on the pulmonary mechanic events [static and dynamic elastance, resistive (DeltaP1) and viscoelastic pressures (DeltaP2)] and histology after intramuscular injection of saline solution (control) or venom (0.6 microg/g). The static and dynamic elastance values were increased significantly after 3 h of venom inoculation, but were reduced at control values in the other periods studied. The DeltaP1 values that correspond to the resistive properties of lung tissue presented a significant increase after 6h of CdtV injection, reducing to basal levels 12h after the venom injection. In DeltaP2 analysis, correspondent to viscoelastic components, an increase occurred 12 h after the venom injection, returning to control values at 24 h. CdtV also caused an increase of leukocytes recruitment (3-24 h) to the airways wall as well as to the lung parenchyma. In conclusion, C. durissus terrificus rattlesnake venom leads to lung injury which is reverted, after 24 h of inoculation.