INTRODUCTION: maximum inspiratory (IPmax) and expiratory (EPmax) pressures constitute a simple noninvasive method for evaluation of respiratory muscle strength which helps in the identification of muscle weakness usually present in several diseases and clinical situations, such as quadriplegia. OBJECTIVE: to assess the number of maneuvers needed to achieve maximum pressures in patients with quadriplegia. METHODS: eight quadriplegic patients (seven men) with mean age of 37.8 ± 11.96 years old and presenting with diagnosis of complete spinal cord lesion were submitted to 10 measurements of IPmax and EPmax in both seated and supine positions, totalizing 320 measurements. Data were compared by using the Wilcoxon's test (p<0.05). RESULTS: the 1st and 10th measurements of IPmax and EPmax for seated position ranged from 74.1±15.1 to 74.8±19.8 cmH2O and 32.4±6.8 to 32.4±9.0 cmH2O, respectively; whereas for supine position such measurements ranged from 76.5±18.6 to 91.1±13.3 cmH2O (p<0.05) and 32.5±5.8 to 32.9±5.1 cmH2O, respectively. The results regarding the 3rd and 5th measurements of IPmax for seated position were 81.1±19.5, 81.5±18.8, and 83.0±18.9 cmH2O; whereas EPmax had 35.0±8.2; 35.3±7.9, and 36.8±8.0 cmH2O. IPmax values for seated position were 90.3±17.8, 94.6±16.0, and 97.4±17.8 cmH2O (p<0.05), whereas EPmax had 33.3±5.8, 35.6±5.4, and 36.9±4.9 cmH2O. The highest value occurred from the 6th measurement in 40% of the tests. CONCLUSIONS: To obtain maximum values for respiratory pressures in quadriplegic patients, it is necessary to repeat the measurements at least 10 times for each evaluation.
Quadriplegia; Respiratory muscles; Muscle strength; Evaluation; Manometry
