252 . Respiratory and skeletal muscle assessment in health and disease

printing supported by . Visit Chiesi at Stand D.30 MONDAY, SEPTEMBER 26TH 2011 The evidence base for conservative treatment is limited but two single-case reports suggest effects from inspiratory muscle strength training (IMST). Objectives: To run a pilot study that objectively visualizes laryngeal response pattern(s) to controlled training with IMST. Methods: Ten healthy volunteers (range 21-26), were examined at rest with video recorded continuous transnasal flexible laryngoscopy while performing a standardized training program using a resistive loading device (Respifit S). The resistance during the training sessions were set at maximal and 60-80% of the maximal attainable inspiratory mouth pressure (PImax ). Laryngeal movements were scored by a senior laryngologist according to a preset scheme. Results: Resistance set at 60-80% of PImax produced a measurable glottic abduction in all subjects. Increasing the inspiratory pressure to PImax, revealed no change in the abduction in seven subjects, while in two subjects abduction appeared to decrease. In one subject a paradoxical adduction was observed. Supraglottic adduction was seen in two patients at PImax. In all subjects larynx moved downwards during inspiration, and nine of ten subjects seemed to engaged all muscle groups in the hypopharynx during inspiration at PImax . Conclusion: The study suggests that IMST may be an efficient tool in the treatment of exercise induced VCD. Large interindividual differences suggest a need for individual training programs, and underscores that objective methods must be used during instructions and training with IMST in these patients. P2109 Diaphragm and quadriceps muscle fatigue in self-paced cycling exercise of different durations Elisabeth C. Eberle1, Thomas Wüthrich1, Christina M. Spengler1,2. 1Institute of Human Movement Sciences, ETH Zurich, Zurich, Switzerland; 2Institute of Physiology and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland Introduction: Individuals are believed to pace cycling intensity in a time trial (TT) such that the level of quadriceps muscle fatigue (QF) attained is similar independent of cycling conditions. We aimed to assess whether diaphragm fatigue (DF), known to affect leg muscle fatigue, would also reach similar levels between different tests. Methods: 12 healthy, young athletes (67.1±6.3 ml min-1 kg-1) performed 15 and 30min cycling time trials (15TT, 30TT; randomised), on two different days. DF and QF were assessed by measuring reductions in esophageal and gastric (transdiaphragmatic) pressure/quadriceps force during magnetic phrenic/femoral nerve stimulation after exercise relative to before ( Pdi,tw; Qtw). Results: The average degree of Pdi,tw did not differ -21.2±12.8% (15TT) vs. -17.6±9.3% (30TT; p=0.228) while Qtw of the shorter and more intensive test -34.0±5.7% (15TT) was significantly larger than that of the longer test -29.5±6.9% (30TT; p=0.044). Individual between-test differences of Pdi,tw did not correlate with those of Qtw. However, individual Pdi,tw of both TTs taken together significantly correlated with the workload of the finish (last 30 s) relative to the maximal workload (R2=0.30; p=0.005). Conclusion: The present work does not support the notion that the level of QF is the same, independent of cycling TT conditions. Knowing that DF develops early during exercise, these findings may indicate that DF possibly affected finish intensity via afferent feedback from the fatigued diaphragm, attenuating central motor output to working limb muscles. P2110 Dyspnoea, respiratory muscle strength and hyperventilation in end-stage liver disease Georgios Kaltsakas1, Efstathios Antoniou2, Anastasios Palamidas1, Panorea Paraskeva2, Sofia-Antiopi Genimmata1, Georgios Dionellis1, Joseph Milic-Emili3, Manos Alchanatis1, Nikolaos G. Koulouris1. 11st Respiratory Medicine Dept, Athens University, Athens, Attica, Greece; 2Liver Surgery and Transplantation Unit, 2nd Propaedeutic Department of Surgery, Athens University, Athens, Attica, Greece; 3Meakins-Christie Labs, McGill University, Montreal, Canada There are scarce reports on respiratory muscle strength in end-stage liver disease patients. On the other hand, decreased PaCO2 due to hyperventilation is well documented in patients with end-stage liver disease. Chronic dyspnoea is frequently reported by these patients, but it is not known if it is related to respiratory muscle strength and/or hyperventilation. We studied 48 consecutive, ambulatory, Caucasian patients (37 men) with end-stage liver disease, awaiting for liver transplantation. Chronic dyspnoea was rated according to the modified Medical Research Council (mMRC) 6-point scale. Routine lung function tests, maximum static expiratory (Pemax) and inspiratory (Pimax) mouth pressures were measured. Pattern of breathing (VE: minute ventilation; VT: tidal volume; RR: respiratory rate; VT/TI: mean inspiratory flow; TI/TTOT: duty cycle; TI: duration of inspiration) was also measured. Forty-three patients reported some degree of dyspnoea (mean±SD). mMRC was 2±1.1, Pemax%pred was 106±33 and Pimax%pred was 91±28. These pressures were found below the normal limits in 13 and 16 patients, respectively. Furthermore, mMRC was significantly correlated with Pemax and Pimax (r=-0.49, p<0.001; r=-0.41, p<0.01, respectively). VE (11.5±3.4, l), VT (0.770±0.311, l), RR (16±4, bpm) and VT/TI (0.46±0.13, l sec-1) were increased and PaCO2 (33±4, mmHg) was decreased, indicating hyperventilation. In contrast TI/TTOT (0.42±0.05) was normal. Statistically significant correlations were found for mMRC with TI and RR (r=-0.32, p=0.03; r=0.32, p=0.03; respectively). We conclude that in end-stage liver disease, there is an interrelationship between chronic dyspnoea, respiratory muscle strength, and hyperventilation. P2111 Reproducibility of diaphragm thickness measurements by ultrasonography Marianna Laviola, Caterina Salito, Andrea Aliverti. Dip. Bioingegneria, Politecnico di Milano, Milano, Italy Although diaphragmatic variations of the length of zone of apposition are readily studied by ultrasonography (US), only preliminary studies have shown the possibility to use US to measure diaphragmatic thickness (TD). In order to determine reference values of TD during various maneuvers and to assess US measurement reproducibility, 8 healthy subjects (4M, 4F) were studied in supine and standing position during spontaneous quiet breathing (QB), slow vital capacity (SVC), maximal inspiratory (MIP) and maximal expiratory (MEP) pressure maneuvers. TD was measured on lateral ribcage using an US linear probe (7.5 MHz). Six subjects were examined by two different operators on two different occasions on a short time period (2-3 days). Three subjects were examined by the same operator on two different occasions on a long time period (6-7 months). TD was determined by a custom-designed software for image processing at end-inspiration (EI) and end-expiration (EE) during QB, at TLC and at maximal pressures during MIP and MEP maneuvers. Overall average values are reported in the following table (values reported as mean±SD). Diaphragm thickness (TD, mm) QB, EE QB, EI QB, EI-EE TLC MIP MEP Supine 1.45±0.45 1.83±0.54 0.38±0.42 2.80±0.66 3.29±0.68 1.18±0.27 Standing 1.56±0.36 1.91±0.49 0.36±0.44 2.68±0.70 3.25±0.82 1.19±0.30 ANOVA analysis revealed that no significant differences were present between interand intra-observer measures, in both postures, and on both short and long time periods (p>0.05). In conclusion: a) US represent a reliable and reproducible method for TD assessment; b) TD varies of ∼30% and ∼20% in supine and standing position during QB; c) at TLC, TD is about two-fold higher than at FRC; d) during MIP, TD is maximum. P2112 Effects of cardiomegaly on regional chest wall volume in patients with chronic Chagas cardiomyopathy Joao Danyell Silva1, Daniella Brandao1, Jasiel Nascimento Jr.1, Larissa Carvalho1, Wilson Oliveira Junior2, Raquel Britto3, Guilherme Fregonezi4, Andrea Aliverti5, Armele Dornelas de Andrade1. 1Departamento de Fisioterapia, Universidade Federal de Pernambuco, Recife, Brazil; 2Procape, Universidade de Pernambuco, Recife, Brazil; 3Departamento de Fisioterapia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; 4Departamento de Fisioterapia, Universidade Federal do Rio Grande do Norte, Natal, Brazil; 5Dipartimento di Bioingegneria, Politecnico di Milano, Milano,