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Maximal Inspiratory Pressure (maximal + inspiratory_pressure)
Selected AbstractsRespiratory muscle performance with stretch-shortening cycle manoeuvres: maximal inspiratory pressure,flow curvesACTA PHYSIOLOGICA, Issue 3 2005G. E. Tzelepis Abstract Aim:, To test the hypothesis that the maximal inspiratory muscle (IM) performance, as assessed by the maximal IM pressure,flow relationship, is enhanced with the stretch-shortening cycle (SSC). Methods:, Maximal inspiratory flow,pressure curves were measured in 12 healthy volunteers (35 ± 6 years) during maximal single efforts through a range of graded resistors (4-, 6-, and 8-mm diameter orifices), against an occluded airway, and with a minimal load (wide-open resistor). Maximal inspiratory efforts were initiated at a volume near residual lung volume (RV). The subjects exhaled to RV using slow (S) or fast (F) manoeuvres. With the S manoeuvre, they exhaled slowly to RV and held the breath at RV for about 4 s prior to maximal inspiration. With the F manoeuvre, they exhaled rapidly to RV and immediately inhaled maximally without a post-expiratory hold; a strategy designed to enhance inspiratory pressure via the SSC. Results:, The maximal inspiratory pressure,flow relationship was linear with the S and F manoeuvres (r2 = 0.88 for S and r2 = 0.88 for F manoeuvre, P < 0.0005 in all subjects). With the F manoeuvre, the pressure,flow relationship shifted to the right in a parallel fashion and the calculated maximal power increased by approximately 10% (P < 0.05) over that calculated with the S manoeuvre. Conclusion:, The maximal inspiratory pressure,flow capacity can be enhanced with SSC manoeuvres in a manner analogous to increases in the force,velocity relationship with SSC reported for skeletal muscles. [source] Prethymectomy plasmapheresis in myasthenia gravisJOURNAL OF CLINICAL APHERESIS, Issue 4 2005Jiann-Horng Yeh Abstract Plasma exchange before thymectomy may decrease the time on mechanical ventilation (MV) and shorten the stay in the intensive care unit (ICU) for patients with myasthenia gravis (MG). This study evaluated the effects of prethymectomy plasmapheresis. A total of 29 myasthenic patients, 18 women and 11 men aged 20,73 years, were treated with double filtration plasmapheresis (DFP) for two to five consecutive sessions over a period between 2 and 21 days (mean 8.1 days) before transsternal thymectomy. Acetylcholine receptor antibody (AchRAb) titers, vital capacity (VC), maximal inspiratory pressure (Pimax), and MG score were measured before and after the course of DFP. Three outcome measures including duration of postoperative hospital stay, duration of ICU stay, and duration of MV were analyzed for correlation with clinical variables. The duration of MV ranged from 6 to 93 h, with a median of 21 h. The median ICU stay was one day and the median postoperative hospital stay was 10 days. A higher removal rate of AchRAb was associated with a shorter duration of ICU and postoperative hospital stay (P = 0.001 and 0.019, respectively). Postoperative hospital stay was strongly correlated with post-DFP Pimax (P = 0.010), and marginally correlated with pre-DFP VC (P = 0.047) and to a lesser extent with pre-DFP Pimax (P = 0.063). Univariate analysis using the log rank test revealed that removal rate of AchRAb <30% (P = 0.043) and pre-DFP Pimax <,60 cmH2O (P = 0.024) were significantly associated with prolonged ICU stay. Risk factors for prolonged postoperative stay included post-DFP Pimax <,60 cmH2O (P = 0.017), pre-DFP Pimax <,60 cmH2O (P = 0.031), and post-DFP VC < 1.0 L (P = 0.046). Our results confirmed the efficacy and safety of DFP in prethymectomy preparation for myasthenic patients. J. Clin. Apheresis, 2005 © 2005 Wiley-Liss, Inc. [source] Which pulmonary volume should be used in physiotherapy to obtain higher maximal inspiratory pressure in COPD patients?PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 4 2005Patricia EM Marinho Abstract Background and Purpose Patients with chronic obstructive pulmonary disease (COPD) present pulmonary hyperinflation as the main cause of mechanical disadvantage in respiratory muscles. Measurement of the force generated by those muscles is converted into pressure changes. The aim of the present study was to evaluate the maximal inspiratory pressure (MIP) from the residual volume (RV) and from the functional residual capacity (FRC), in patients with COPD, and to determine which pulmonary volume should be used in physiotherapy so as to obtain higher MIP results. Method An investigation of 18 male patients with stable COPD. Patients were examined using a manual vacuometer to measur the MIP of 20 daily manoeuvres. Ten measurements were taken from the RV and 10 from the FRC, taken alternately with an interval of 1 minute between each measurement, for five consecutive days. Results Increases in MIP were obtained from the RV measurements (mean ± SE) from 59.7 (±5.2) to 66.6 (±5.3) cm H2O (F (4,64) = 3.34; p < 0.015) and from the FRC measurements, from 55.4 (±4.9) to 64.4 (±4,8) cm H2O (F (4,64) = 6.72; p < 0.001). Post hoc analysis showed an increase, over consecutive days, in both RV and FRC. For FRC, an increase was revealed on the second and third days, a fall was found on the fourth day and a new increase was found on the last day. MIP reached different levels, between RV and FRC, on the first (t = 2.888; p = 0.010) and fourth ( t = 2.165; p = 0.045) days. Conclusion In the present study, MIP reached higher levels at FRC during the five days of evaluation, and a learning effect occurred in the patients. Motor units from the respiratory muscles may have been recruited in order to performe the manoeuvres during the days of evaluation. The study suggests that there is good evidence for the use of the FRC as a parameter to find the major MIP value. Copyright © 2005 John Wiley & Sons, Ltd. [source] | ||||||||||