Paresia adquirida na terapia intensiva: uso da dinamometria de preensão palmar para avaliação diagnóstica e prognóstica

Abstract

Background: Intensive care unit acquired weakness (ICUAW) is an important and prevalent problem for individuals that survive the initial insult of a critical illness. Strength assessment using the six-point Medical Research Council (MRC) score is currently the recommended method for diagnosing ICUAW. Handgrip strength dynamometry has been proposed as a simple and easy diagnostic method for ICUAW. We performed this study to test the agreement between handgrip dynamometry and MRC criteria for the diagnosis of ICUAW and to evaluate if dynamometry findings are associated with morbidity and mortality in critically ill patients hospitalized in a Brazilian ICU. Methods: A prospective single center cohort study was conducted in a mixed medical and surgical ICU in Brazil. Adults requiring at least 5 days of critical care without evidence of preexisting neuromuscular disease were followed until responding commands and then examined for strength. The agreement between ICUAW diagnosis as assessed by the MRC score and the handgrip strength dynamometry was evaluated using the Kappa coefficient. The primary outcomes were in-ICU, inhospital, 6-month and one-year mortality. Secondary outcomes were days of mechanical ventilation, length of ICU and hospital stay (in the present hospitalization and during the 6-month follow-up) and ICU readmission in six months. Main Results: We included 45 consecutive subjects. The mean age of included subjects was 55.3 (±16.3) and 40% were males. The median SAPS 3 score was 65 (50-79).The incidence of ICUAW (MRC score < 48) was 40%. Handgrip strength was lower in subjects with ICUAW. Using sex specific thresholds (males, <11 kg-force; females, < 7 kg-force), handgrip strength had perfect agreement with MRC criteria for ICUAW diagnosis (Kappa = 1; p<0,001). There was no association between ICUAW and in-hospital, in-ICU, 6-month or one-year mortality. ICUAW was associated with more days of mechanical ventilation (P < 0.001) and longer length of ICU stay (P <0.001). This difference persisted in the following six months, period in which the number of in-hospital days was also higher among the group with ICUAW. Conclusion: Handgrip strength dynamometry had perfect performance when compared to MRC criteria for the diagnosis of ICUAW. Considering the accuracy and simplicity of this method, it may be used as a surrogate for MRC strength examination. ICUAW is associated with long term morbidity. More studies are needed to further increase ICUAW comprehension and recognition.