Effects of diaphragmatic control on the assessment of sniff nasal inspiratory pressure and maximum relaxation rate

OBJECTIVE: To assess the influence of diaphragmatic activation control (diaphC) on Sniff Nasal-Inspiratory Pressure (SNIP) and Maximum Relaxation Rate of inspiratory muscles (MRR) in healthy subjects. METHOD: Twenty subjects (9 male; age: 23 (SD=2.9) years; BMI: 23.8 (SD=3) kg/m2; FEV1/FVC: 0.9 (SD=0.1)] performed 5 sniff maneuvers in two different moments: with or without instruction on diaphC. Before the first maneuver, a brief explanation was given to the subjects on how to perform the sniff test. For sniff test with diaphC, subjects were instructed to perform intense diaphragm activation. The best SNIP and MRR values were used for analysis. MRR was calculated as the ratio of first derivative of pressure over time (dP/dtmax) and were normalized by dividing it by peak pressure (SNIP) from the same maneuver. RESULTS: SNIP values were significantly different in maneuvers with and without diaphC [without diaphC: -100 (SD=27.1) cmH2O/ with diaphC: -72.8 (SD=22.3) cmH2O; p<0.0001], normalized MRR values were not statistically different [without diaphC: -9.7 (SD=2.6); with diaphC: -8.9 (SD=1.5); p=0.19]. Without diaphC, 40% of the sample did not reach the appropriate sniff criteria found in the literature. CONCLUSION: Diaphragmatic control performed during SNIP test influences obtained inspiratory pressure, being lower when diaphC is performed. However, there was no influence on normalized MRR.

Reference Range of Respiratory Muscle Strength and Its Clinical Application in Amyotrophic Lateral Sclerosis: A Single-Center Study

BACKGROUND AND PURPOSE: Evaluating respiratory function is important in neuromuscular diseases. This study explored the reference ranges of the maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), and sniff nasal inspiratory pressure (SNIP) in healthy adults, and applied them to amyotrophic lateral sclerosis (ALS) patients. METHODS: MIP, MEP, and SNIP were measured in 67 healthy volunteers aged from 21 to 82 years. Reference ranges were evaluated by multivariate regression analysis using the generalized additive modeling of location, scale, and shape method. Thirty-six ALS patients were reviewed retrospectively, and abnormal values of MIP, MEP, and SNIP were determined according to the reference ranges. RESULTS: MIP, MEP, and SNIP were abnormal in 57.1%, 51.4%, and 25.7% of the ALS patients, respectively. MIP and SNIP were significantly correlated with the degree of restrictive pattern and respiratory symptoms. The ALS Functional Rating Scale-Revised score was correlated with SNIP. CONCLUSIONS: This study has provided the reference range of respiratory muscle strength in healthy adults. This range is suitable for evaluating respiratory function in ALS patients.

Sniff Nasal Inspiratory Pressure in 299 Healthy Boys / 中国康复理论与实践

Objective To investigate the sniff nasal inspiratory pressure (SNIP) of Chinese boys. Methods 299 healthy boys aged 5-12 years were measured with SNIP. Their height, weight, and age were recorded. Results The SNIP averaged (76.9 ± 22.6) cmH2O, and was (59.1±14.2) cmH2O, (76.9±19.5) cmH2O, (85.3±23.5) cmH2O and (83.0±22.6) cmH2O in the boys of 5-6 years old, 7-8 years old, 9-10 years old and 11-12 years old, respectively. It was significantly different among boys of 5-6 years old, 7-8 years old and 9-10 years old (P<0.05), but no significant difference between 9-10 years old and 11-12 years old (P=0.55). Regression analysis indicated significant relations of SNIP with age, height, weight and Body Mass Index (P<0.01). Conclusion The SNIP of Chinese healthy boys are different from abroad. It is necessary to establish the Chinese children SNIP reference range.

Sniff Nasal Inspiratory Pressure in 299 Healthy Boys / 中国康复理论与实践

@#Objective To investigate the sniff nasal inspiratory pressure (SNIP) of Chinese boys. Methods 299 healthy boys aged 5-12 years were measured with SNIP. Their height, weight, and age were recorded. Results The SNIP averaged (76.9±22.6) cmH2O, and was (59.1±14.2) cmH2O, (76.9±19.5) cmH2O, (85.3±23.5) cmH2O and (83.0±22.6) cmH2O in the boys of 5-6 years old, 7-8 years old, 9-10 years old and 11-12 years old, respectively. It was significantly different among boys of 5-6 years old, 7-8 years old and 9-10 years old (P<0.05), but no significant difference between 9-10 years old and 11-12 years old (P=0.55). Regression analysis indicated significant relations of SNIP with age, height, weight and Body Mass Index (P<0.01). Conclusion The SNIP of Chinese healthy boys are different from abroad. It is necessary to establish the Chinese children SNIP reference range.

Sniff Nasal Inspiratory Pressure in 299 Healthy Boys / 中国康复理论与实践

@#Objective To investigate the sniff nasal inspiratory pressure (SNIP) of Chinese boys. Methods 299 healthy boys aged 5-12 years were measured with SNIP. Their height, weight, and age were recorded. Results The SNIP averaged (76.9±22.6) cmH2O, and was (59.1±14.2) cmH2O, (76.9±19.5) cmH2O, (85.3±23.5) cmH2O and (83.0±22.6) cmH2O in the boys of 5-6 years old, 7-8 years old, 9-10 years old and 11-12 years old, respectively. It was significantly different among boys of 5-6 years old, 7-8 years old and 9-10 years old (P<0.05), but no significant difference between 9-10 years old and 11-12 years old (P=0.55). Regression analysis indicated significant relations of SNIP with age, height, weight and Body Mass Index (P<0.01). Conclusion The SNIP of Chinese healthy boys are different from abroad. It is necessary to establish the Chinese children SNIP reference range.

Comparação entre o manovacuômetro nacional e o importado para medida da pressão inspiratória nasal / Comparison between a national and a foreign manovacuometer for nasal inspiratory pressure measurement

CONTEXTUALIZAÇÃO: A medida da pressão inspiratória nasal, conhecida como sniff teste, desenvolvida como um novo teste de força muscular inspiratória, utilizada principalmente em doenças neuromusculares, é de fácil realização e não invasiva. Apesar da importância clínica da avaliação da pressão inspiratória nasal, não existe um instrumento nacional disponível para realizá-la. OBJETIVOS: Comparar os manovacuômetros eletrônicos nacional e importado para a avaliação da pressão inspiratória nasal em pessoas saudáveis. MÉTODOS: Foram avaliados 18 voluntários saudáveis (idade 21,4±2,8 anos, IMC 23,4±2,5 Kg/m² , CVF 102,1±10,3 por centopred, VEF1 98,4±1 por centopred) por meio de duas medidas de pressão inspiratória nasal em dois equipamentos diferentes: um nacional e outro importado. Todos os sujeitos realizaram a manobra no mesmo horário do dia, em dias ocasionais, sendo a ordem determinada aleatoriamente. Para análise estatística, foi utilizado o teste t pareado, a correlação de Pearson e o Bland-Altman com nível de significância de 5 por cento. RESULTADOS: As médias encontradas durante as duas medidas das pressões nasais foram de 125±42,4 cmH2O para o aparelho importado e de 131,7±28,7 cmH2O para o nacional. A análise de Pearson demonstrou uma correlação significativa entre as médias, com um coeficiente r=0,63. Os valores médios não apresentaram diferenças significativas pelo teste t pareado (p>0,05). Na análise de Bland-Altman, encontrou-se um BIAS igual a 7 cm H2O, desvio-padrão de 32,9 cmH2O para o DP e um intervalo de confiança de -57,5 cmH2O até 71,5 cmH2O. CONCLUSÃO: Os resultados encontrados sugerem que o manovacuômetro eletrônico nacional é viável e seguro para realização do sniff teste em sujeitos saudáveis.

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±2.8 years, BMI 23.4±2.5 kg/m² , FVC 102.1±10.3 percent pred, FEV1 98.4±1 percent 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 percent significance level. RESULTS: The averages observed for the two measures of nasal pressures were 125±42.4 cmH2O for the foreign equipment, and 131.7±28.7 cmH2O 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±SD found in Bland-Altman plot analysis was 7 cmH2O with limits of agreement between -57.5 cmH2O and 71.5 cmH2O. CONCLUSION: The results suggest that the national electronic device is feasible and safe to the sniff test measurement in healthy subjects.

Clinical Implication of Sniff Nasal Inspiratory Pressure in Patients with Amyotrophic Lateral Sclerosis

OBJECTIVE: To evaluate sniff nasal inspiratory pressure (SNIP) in patients with amyotrophic lateral sclerosis (ALS), to analyse the relationship between SNIP and other pulmonary function test and to verify the usefulness of SNIP in patients with ALS. METHOD: Twenty-eight patients with ALS able to follow command were studied. SNIP and maximal inspiratory pressure (MIP) were measured using respiratory pressure meter in sitting position. Forced vital capacity (FVC) and peak cough flow (PCF) were evaluated using spirometer and peak flow meter respectively. The relationship between SNIP and other pulmonary function parameters were analysed. RESULTS: The mean value of SNIP was -20.7 cmH2O (21.7% predicted) and the mean value of MIP was -16.3 cmH2O (8.0% predicted). SNIP correlated with MIP (r=0.776, p= 0.000). When expressed absolute value, SNIP was higher than MIP in twenty-one of the twenty-eight patients with ALS. Difference of SNIP and MIP was 4.4 cmH2O and it was statistically significant (p=0.001). SNIP and MIP correlated with FVC. SNIP and MIP correlated with PCF as well. CONCLUSION: SNIP in patients with ALS is useful method to assess inspiratory muscle strength in addition to MIP.

Clinical Assessment of Rhinitis with Respiratory Pressure Meter / 소아알레르기및호흡기학회지

PURPOSE: Nasal stuffness is one of most common symptom in children who suffer from rhinitis although there is still debates at to the best measurable device. The aim of the study was to evaluate the sniff nasal inspiratory pressure (SNIP) with respiratory pressure meter and compare this with the clinical status of patients. METHODS: We enrolled 57 rhinitis patients who visited our hospital during June 2005 to July 2006. They were treated with intranasal steroid spray (mometasone furoate) for first 2 weeks. To evaluate the outcome of treatment, we used symptom score (SS) and measured the SNIP with respiratory pressure meter (Micro RPM, Micro Medical, Rochester, UK) and also measured peak nasal inspiratory flow (PNIF) with peak nasal inspiratory flow meter (Youlten peak flow meter, Clement Clarke Int., London, UK) before and after the therapy. Skin prick test was performed to all patient to classify the atopic (AR) and non-atopic rhinitis (NAR). RESULTS: Among 57 identified patients (median age, 7 years 9 months), 40 AR and 17 NAR were studied. Most patient showed clinically improvement with 2 weeks intranasal steroid therapy (0 wk SS=4.9, 2 wk SS=1.7 in AR; 0 wk SS=4.5, 2 wk SS=1.5 in NAR, P77.6 L/min, P>0.05). And there was no correlation between SNIP and PNIF measurement. CONCLUSION: The respiratory pressure meter is a useful device to evaluate the therapeutic effectiveness and clinical improvement in pediatric rhinitis patients.

Clinical Implication of Sniff Nasal Inspiratory Pressure in Patients with Duchenne Muscular Dystrophy

OBJECTIVE: To evaluate sniff nasal inspiratory pressure (SNIP) in patients with Duchenne muscular dystrophy (DMD), to analyse the relationship SNIP and other pulmonary function test and to verify the usefulness of SNIP in patients with DMD. METHOD: Twenty-seven patients with DMD who were able to follow commend were studied. Among them two patients were unable to perform maximal inspiratory pressure (MIP) mesurement. SNIP and MIP were measured using respiratory pressure meter in sitting position. Forced vital capacity (FVC) and peak cough flow (PCF) were evaluated using spirometer and peak flow meter respectively. The relationship between SNIP and other pulmonary function parameters were analysed. RESULTS: The mean value of SNIP was -44.9 cmH2O (41.6% predicted) and the mean value of MIP was -32.9 cmH2O (43.9% predicted). SNIP was correlated with MIP. When expressed absolute value, SNIP was higher than MIP in 23 of the 25 patients with DMD. SNIP and MIP were correlated with FVC. SNIP and MIP were correlated with PCF as well. CONCLUSION: SNIP in patients with DMD is useful method to assess inspiratory muscle strength in addition to MIP and more easier to perform than MIP.