Study On The Risk Factors Of Critically Ill Acquired Frailty And Analysis Of MRC Score And Electromyographic Characteristics

Background:Intensive care unit acquired weakness(ICU-AW)is a common neuromuscular complication of patients in intensive care unit(ICU).The most common clinical manifestation is symmetrical limb weakness.Early detection of risk factors of ICU-AW and early diagnosis of ICU-AW are helpful to reduce complications related to mechanical ventilation and improve the quality of life of patients after leaving ICU.At present,there are few studies about risk factors,MRC score,electromyogram characteristics and prognosis of ICU-AW in China.Objective:To explore the risk factors,MRC score characteristics,electromyogram characteristics and prognosis of ICU-AW in medical ICU.Methods:This study is a prospective case-control study which analyzes patients admitting to the fourth department of respiratory and critical care medicine(medical ICU)of China-Japan Friendship Hospital from September 2018 to Januar y 2020.Patients with mechanical ventilation time ≥ 7 days have MRC score.The patients were divided into ICU-AW group and non ICU-AW group according to the diagnostic criteria of ICU-AW.Collect their clinical information.Result:1.A total of 60 patients were included in the study,including 17 patients(28.3%)in ICU-AW group and 43 patients(71.7%)in non ICU-AW group.2.Demographic characyeristic:among the 17 patients with ICU-AW,10 were male(58.8%),7 were female(41.2%),the age ranges from 19 to 89 years,the median age was 71(59,79)years,43 patients in non ICU-AW group,32 were male(74.4%),11 were female(25.6%),the age ranges from 26 to 90 years,the median age was 64(56,75)years.3.Risk factors:higher APACHE Ⅱ score within 24 hours of entering ICU(21(18,25)vs 18(15,22),P=.037),higher SOFA score within 24 hours of entering ICU(7(5,12)vs 5(3,8),P=.047),higher brain natriuretic peptide(BNP)of first day(364.3(210.1,551.2)pg/ml vs 160.1(66.8,357.8)pg/ml,P=.035),higher urea nitrogen(urea)of first day(9.9(6.2,17.0)mmol/L vs 6.0(4.8,9.8)mmol/L,P=.020),the use of invasive mechanical ventilation(88.2%(15)vs 46.5%(20),P=.003).4.MRC score:the average MRC score of 17 patients in ICU-AW group was 33 points(range from 8 to 44 points),which was symmetrical limb weakness,mainly proximal limb weakness.5.Electromyogram:in the eight ICU-AW patients completing electromyogram,8(100%)completed nerve conduction test,and 4(50%)completed needle electromyogram.The amplitude of compound muscle action potentials(CMAPs)was decreased(6,75%)and the amplitude of sensory nerve action potential(SNAP)was decreased(4,50%).In needle electromyography,the area of motor unit potential(MUP)increased,the time prolonged(1,25%)and a large number of spontaneous potentials(2,50%)were observed.6.Prognosis:compared with the control group,more patients in ICU-AW group underwent tracheotomy(70.6%vs 11.6%,P=.001),and the average length of stay was longer(57±52 days vs 16±8 days,P<.001),more patients had rehabilitation(58.8%vs 14.0%,P=.001).There was no significant difference between the two groups(17.6%vs 9.3%,P=.393).Conclusion:In this study,the risk factors of ICU-AW include the higher level of APACHE Ⅱ score within 24 hours of entering ICU,higher SOFA score within 24 hours of entering ICU,higher BNP(Day1)level,higher urea(Day1)level and invasive mechanical ventilation.Early recognition of these factors can predict the occurrence of ICU-AW.The MRC score of ICU-AW puts up symmetrical limb weakness,mainly proximal limb weakness.In the electromyogram examination of ICU-AW,the main manifestations of nerve conduction examination are the decrease of amplitude of compound muscle action potentials(CMAPs)and sensory nerve action potential(SNAP),the increase of motor unit potential(MUP)area,the extension of time and a large number of spontaneous potentials.This study found that there was a good consistency between electromyogram and MRC score in the diagnosis of ICU-AW in the patients without basic neuromuscular diseases and myodynamia.Therefore,for such patients,ICU doctors can choose a simple MRC score to make clear the diagnosis of ICU-AW.For patients with previous basic neuromuscular diseases or muscle strength abnormalities,if there are risk factors related to ICU-AW,clinical suspicion of ICU-AW,the diagnosis of ICU-AW still needs to be confirmed by electromyogram.