Clinical trial NCT01436318: Respiratory Muscle Strength and Function in Healthy Kids
Official title: Respiratory Muscle Strength and Function in Healthy Children
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Respiratory Muscle Strength
Keywords: Healthy Kids
Respiratory
Volunteers
Lead sponsor: University of Florida
Sponsor class: OTHER
First posted: 2011-09-19
Enrollment: 7
Sex: ALL
Minimum age (years): 4
Maximum age (years): 16
Standard ages: CHILD
Accepts healthy volunteers: yes
Observational model: ECOLOGIC_OR_COMMUNITY
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: Healthy Children

Brief summary: Respiratory muscle strength training (RMST) is a potential treatment option that has been shown to increase strength and ventilatory function in critically ill patients, patients on ventilators and patients with mild neuromuscular weakness. Currently researchers are examining the role of inspiratory muscle strength training (IMST) in pressure performance of ventilator dependent children with Pompe disease. However, normal pressure-flow-timing responses of lung function are not well-characterized in healthy children. The purpose of this study is to measure RMST-induced changes in respiratory function in healthy children. Children will undergo one session of lung function and strength testing. By studying healthy children's respiratory function, this study will also help to develop more efficient respiratory muscle training exercise prescriptions for children with neuromuscular weakness and impaired respiratory function.

Detailed description: The goals of this study are to collect and evaluate respiratory muscle strength training (RMST) induced changes in ventilatory function in healthy children. Children will undergo one session of pulmonary function and strength testing to quantify rate of inspiratory and expiratory pressure development and to determine whether inspiratory and expiratory pressure correlate to maximal respiratory pressures and forced pulmonary function tests. Currently normal pressure-flow-timing responses are not well-characterized in healthy children. The purpose of this study is to help develop more efficient RMST exercise prescriptions for ill children on ventilators and with neuromuscular weakness.

Participants in the study will refrain from caffeine products and exercise on the day of respiratory testing. In conjunction with respiratory testing, baseline and exertional blood pressure, heart and respiratory rate, and pulse oximetry will be monitored. Participants will complete tidal flow-volume assessments and forced expiratory maneuvers according to the AMerican Thoracic Society guidelines. Participants will undergo 5 sets of 10 maximal-effort breaths against standardized resistances (one set each at 0, 5, 10, 15, and 20 cm H20). Following each set, subjects will rate the load magnitude and their feelings of breathing discomfort using a 0-10 visual analog scale. Participants will also perform maximal inspiratory and expiratory pressure maneuvers. All tests will be separated by at least 2-3 minutes of rest.

Eligibility criteria: Inclusion Criteria:

* Male or female subjects 4-16 years of age.
* Healthy subjects

Exclusion Criteria:

* Have primary pulmonary disease
* Have primary neuromuscular disease
* Have a connective tissue or autoimmune disease
* Have had a respiratory infection with in 15 days prior to study date
* Have acute aminoglycosides antibiotic therapy with in 15 days prior to study date
* Have acute corticosteroids with in 15 days prior to study date
* Have a need to use an inhaler routinely
* Have hepatic failure
* Have hematologic failure
* Have participated in other studies related to medications or exercise
* Have used tobacco products
* Have other precautions

Primary outcomes:
measure: Pulmonary Function Testing
timeFrame: Day 1
Secondary outcomes:
Other outcomes:
Locations:
city: Gainesville
country: United States
facility: University of Florida
state: Florida
Study officials:
affiliation: University of Florida
name: Barbara K Smith, PT, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: American Thoracic Society/European Respiratory Society. ATS/ERS Statement on respiratory muscle testing. Am J Respir Crit Care Med. 2002 Aug 15;166(4):518-624. doi: 10.1164/rccm.166.4.518. No abstract available.
citation: Ramonatxo M, Amsalem FA, Mercier JG, Jean R, Prefaut CG. Ventilatory control during exercise in children with mild or moderate asthma. Med Sci Sports Exerc. 1989 Feb;21(1):11-7. doi: 10.1249/00005768-198902000-00003.
citation: Villafranca C, Borzone G, Leiva A, Lisboa C. Effect of inspiratory muscle training with an intermediate load on inspiratory power output in COPD. Eur Respir J. 1998 Jan;11(1):28-33. doi: 10.1183/09031936.98.11010028.
citation: Tzelepis GE, Vega DL, Cohen ME, Fulambarker AM, Patel KK, McCool FD. Pressure-flow specificity of inspiratory muscle training. J Appl Physiol (1985). 1994 Aug;77(2):795-801. doi: 10.1152/jappl.1994.77.2.795.
citation: Tzelepis GE, Kasas V, McCool FD. Inspiratory muscle adaptations following pressure or flow training in humans. Eur J Appl Physiol Occup Physiol. 1999 May;79(6):467-71. doi: 10.1007/s004210050538.
citation: Coast JR, Jensen RA, Cassidy SS, Ramanathan M, Johnson RL Jr. Cardiac output and O2 consumption during inspiratory threshold loaded breathing. J Appl Physiol (1985). 1988 Apr;64(4):1624-8. doi: 10.1152/jappl.1988.64.4.1624.
citation: Romer LM, McConnell AK. Specificity and reversibility of inspiratory muscle training. Med Sci Sports Exerc. 2003 Feb;35(2):237-44. doi: 10.1249/01.MSS.0000048642.58419.1E.
citation: Otis AB. Pressure-flow relationships and power output of breathing. Respir Physiol. 1977 Jun;30(1-2):7-14. doi: 10.1016/0034-5687(77)90017-2.
citation: Mognoni P, Saibene F, Sant'Ambrogio G, Agostoni E. Dynamics of the maximal contraction of the respiratory muscles. Respir Physiol. 1968 Mar;4(2):193-202. doi: 10.1016/0034-5687(68)90051-0. No abstract available.
citation: Read DJ, Freedman S, Kafer ER. Pressures developed by loaded inspiratory muscles in conscious and anesthetized man. J Appl Physiol. 1974 Aug;37(2):207-18. doi: 10.1152/jappl.1974.37.2.207. No abstract available.
citation: Pengelly LD, Alderson AM, Milic-Emili J. Mechanics of the diaphragm. J Appl Physiol. 1971 Jun;30(6):797-805. doi: 10.1152/jappl.1971.30.6.797. No abstract available.
citation: Ameredes BT, Zhan WZ, Prakash YS, Vandenboom R, Sieck GC. Power fatigue of the rat diaphragm muscle. J Appl Physiol (1985). 2000 Dec;89(6):2215-9. doi: 10.1152/jappl.2000.89.6.2215.
citation: Goldman MD, Grassino A, Mead J, Sears TA. Mechanics of the human diaphragm during voluntary contraction: dynamics. J Appl Physiol Respir Environ Exerc Physiol. 1978 Jun;44(6):840-8. doi: 10.1152/jappl.1978.44.6.840.
citation: Fitting JW, Easton PA, Grassino AE. Velocity of shortening of inspiratory muscles and inspiratory flow. J Appl Physiol (1985). 1986 Feb;60(2):670-7. doi: 10.1152/jappl.1986.60.2.670.
citation: Komarow HD, Myles IA, Uzzaman A, Metcalfe DD. Impulse oscillometry in the evaluation of diseases of the airways in children. Ann Allergy Asthma Immunol. 2011 Mar;106(3):191-9. doi: 10.1016/j.anai.2010.11.011. Epub 2011 Jan 6.
citation: Younes M, Riddle W. A model for the relation between respiratory neural and mechanical outputs. I. Theory. J Appl Physiol Respir Environ Exerc Physiol. 1981 Oct;51(4):963-78. doi: 10.1152/jappl.1981.51.4.963.
citation: Parthasarathy S, Jubran A, Laghi F, Tobin MJ. Sternomastoid, rib cage, and expiratory muscle activity during weaning failure. J Appl Physiol (1985). 2007 Jul;103(1):140-7. doi: 10.1152/japplphysiol.00904.2006. Epub 2007 Mar 29.
citation: Butler JE. Drive to the human respiratory muscles. Respir Physiol Neurobiol. 2007 Nov 15;159(2):115-26. doi: 10.1016/j.resp.2007.06.006. Epub 2007 Jun 17.
citation: Rowley KL, Mantilla CB, Sieck GC. Respiratory muscle plasticity. Respir Physiol Neurobiol. 2005 Jul 28;147(2-3):235-51. doi: 10.1016/j.resp.2005.03.003.
citation: Osborne S, Road JD. Diaphragm and phrenic nerve activities during inspiratory loading in anesthetized rabbits. Respir Physiol. 1995 Mar;99(3):321-30. doi: 10.1016/0034-5687(94)00109-d.
citation: American Thoracic Society; European Respiratory Society. ATS/ERS statement: raised volume forced expirations in infants: guidelines for current practice. Am J Respir Crit Care Med. 2005 Dec 1;172(11):1463-71. doi: 10.1164/rccm.200408-1141ST. No abstract available.
citation: Polkey MI, Hamnegard CH, Hughes PD, Rafferty GF, Green M, Moxham J. Influence of acute lung volume change on contractile properties of human diaphragm. J Appl Physiol (1985). 1998 Oct;85(4):1322-8. doi: 10.1152/jappl.1998.85.4.1322.