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

Benício K, Dias FA, Gualdi LP, Aliverti A, Resqueti VR, Fregonezi GA - Braz J Phys Ther (2015)

Bottom Line: 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.However, there was no influence on normalized MRR.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Fisioterapia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.

ABSTRACT

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.

No MeSH data available.


Example of measurement and calculation of Maximum Relaxation Rate ofinspiratory muscles (MRR) from Sniff Nasal Inspiratory Pressure(SNIP).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4835170&req=5

f02: Example of measurement and calculation of Maximum Relaxation Rate ofinspiratory muscles (MRR) from Sniff Nasal Inspiratory Pressure(SNIP).

Mentions: The three best tests from each individual with the highest absolute SNIP value ineach assessment (A and B) were chosen for analysis using the LabChart 7 Pro softwareprogram (ADInstruments 2009). MRRs were calculated from the ratio between the firstderivatives of pressure and time (dP/dtmax), normalized by the pressurepeak of the same test and expressed as percentage pressure fall per 10 ms12,13 (Figure2). For subjects whose Ttotal in their best test was higher than500 ms, their second or third highest SNIP values were used for quantification,whereas those who did not meet this criteria in any of their three best tests wereexcluded and statistics were recalculated for analysis. The Shapiro-Wilk test wasused to verify the normality of variables. SNIP and MRR and their absolute andnormalized values were compared using a paired Student's t-test. Statisticalsignificance was set at p>0.05. Statistical analysis was performed using GraphPadPrism(r), version 5.0 (GraphPad Software, San Diego, CA, USA).


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

Benício K, Dias FA, Gualdi LP, Aliverti A, Resqueti VR, Fregonezi GA - Braz J Phys Ther (2015)

Example of measurement and calculation of Maximum Relaxation Rate ofinspiratory muscles (MRR) from Sniff Nasal Inspiratory Pressure(SNIP).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835170&req=5

f02: Example of measurement and calculation of Maximum Relaxation Rate ofinspiratory muscles (MRR) from Sniff Nasal Inspiratory Pressure(SNIP).
Mentions: The three best tests from each individual with the highest absolute SNIP value ineach assessment (A and B) were chosen for analysis using the LabChart 7 Pro softwareprogram (ADInstruments 2009). MRRs were calculated from the ratio between the firstderivatives of pressure and time (dP/dtmax), normalized by the pressurepeak of the same test and expressed as percentage pressure fall per 10 ms12,13 (Figure2). For subjects whose Ttotal in their best test was higher than500 ms, their second or third highest SNIP values were used for quantification,whereas those who did not meet this criteria in any of their three best tests wereexcluded and statistics were recalculated for analysis. The Shapiro-Wilk test wasused to verify the normality of variables. SNIP and MRR and their absolute andnormalized values were compared using a paired Student's t-test. Statisticalsignificance was set at p>0.05. Statistical analysis was performed using GraphPadPrism(r), version 5.0 (GraphPad Software, San Diego, CA, USA).

Bottom Line: 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.However, there was no influence on normalized MRR.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Fisioterapia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.

ABSTRACT

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.

No MeSH data available.