Erschienen in:
01.10.2012 | Original Article
Vital Capacity Versus Maximal Inspiratory Pressure in Patients with Guillain–Barré Syndrome and Myasthenia Gravis
verfasst von:
Hélène Prigent, David Orlikowski, Nadège Letilly, Line Falaize, Djilali Annane, Tarek Sharshar, Frédéric Lofaso
Erschienen in:
Neurocritical Care
|
Ausgabe 2/2012
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Abstract
Background
The objective is to determine whether maximal inspiratory pressure (P
imax) measurement is more sensitive than vital capacity (VC) measurement to detect acute respiratory muscle failure considering a theoretical curvilinear relationship between volume and pressure.
Methods
Review of VC and P
imax of all patients hospitalized in ICU for Guillain–Barré syndrome (GBS) and myasthenia gravis (MG) exacerbation.
Results
84 consecutive caucasian patients between 19- and 70-years-old hospitalized in intensive care unit from April 2008 to December 2010, for MG exacerbation (44 patients) and GBS (40 patients). The regression curve between VC and P
imax was linear rather than exponential (r = 0.599, P > 0.0001). The contingency table demonstrated agreement between VC and P
imax (χ2 = 26.7, P = 0.0001), with similar number of patients having abnormal P
imax associated to normal VC and normal P
imax associated to abnormal VC (9 (10.7%) vs. 8 (9.5%) respectively). Six of the patients developed an important decrease of VC from normal value to less than 60% of the predicted value and did not present evident curvilinear relationship between VC and P
imax during this follow-up.
Conclusions
Because the regression between VC and P
imax was linear rather than curvilinear, P
imax was not more sensitive than VC for early detection of respiratory muscle failure in patients hospitalized in ICU for GBS and MG exacerbation. Therefore, VC remains well suited to assess acute respiratory muscle failure and P
imax gives poor additional information.