Comparison between a national and a foreign manovacuometer for nasal inspiratory pressure measurement

Background: The measurement of nasal inspiratory pressure, known as the sniff test, was developed as a new test of inspiratory muscle strength, mainly used in neuromuscular conditions. The test is easy to be performed and noninvasive. Despite the clinical importance of assessment of nasal inspiratory pressure a national equipment is not available to assess it. Objectives: To compare a national with a foreign manovacuometer in assessing the nasal inspiratory pressure (sniff test) in healthy subjects. Methods: 18 subjects were evaluated (age 21.44 plus or minus 2.8 years, BMI 23.4 plus or minus 2.5 kg/m super(2), FVC 102.1 plus or minus 10.3% pred, FEV sub(1) 98.4 plus or minus 1% pred). We performed two measures of nasal inspiratory pressure using two different manovacuometer: a national and a foreign. All subjects performed the tests at the same time of day, in different days being the order of the testes established randomly. It was used the paired t test, Pearson correlation and the Bland-Altman plots for statistical analysis considering a 5% significance level. Results: The averages observed for the two measures of nasal pressures were 125 plus or minus 42.4 cmH sub(2)O for the foreign equipment, and 131.7 plus or minus 28.7 cmH sub(2)O for the national equipment. The Pearson correlation showed significant correlation between the means with a coefficient of r=0.63. The t test showed no significant differences between both measurements (p>0,05). The BIAS plus or minus SD found in Bland-Altman plot analysis was 7 cmH sub(2)O with limits of agreement between -57.5 cmH sub(2)O and 71.5 cmH sub(2)O. Conclusion: The results suggest that the national electronic device is feasible and safe to the sniff test measurement in healthy subjects.Original Abstract: Contextualizacao: A medida da pressao inspiratoria nasal, conhecida como sniff teste, desenvolvida como urn novo teste de forca muscular inspiratoria, utilizada principalmente em doencas neuromusculares, e de facil realizacao e nao invasiva. Apesar da importancia clinica da avaliacao da pressao inspiratoria nasal, nao existe urn instrumento nacional disponivel para realiza-la. Objetivos: Comparar os manovacuometros eletronicos nacional e importado para a avaliacao da pressao inspiratoria nasal em pessoas saudaveis. Metodos: Foram avaliados 18 voluntarios saudaveis (idade 21,4 plus or minus 2,8 anos, IMC 23,4 plus or minus 2,5 Kg/m super(2), CVF 102,1 plus or minus 10,3%pred, VEF, 98,4 plus or minus 1%pred) p