Changes Of Blood Amino Acid During Septic Shock

Objective: By measuring blood amino acid levels of septic shock patients,to observe the variations of amino acid concentrations in blood.Changes in amino acid concentrations,correlations with acute physiology and chronic health evaluation Ⅱ(APACHE Ⅱ)score,multiple organ dysfunction(MODS)score,blood lactic acid(Lac)were studied,to provide reasonable nutrition support therapy for septic shock patients.Methods: Collecting 38 septic shock patients who were admitted to the ICU in the First Affiliated Hospital of Dalian Medical University from November 2015 to December 2014.On ICU admission,blood samples were taken after patients met inclusion criteria.Moreover,intravenous blood samples collection were repeated 6 hours,24 hours,and 5 days later if still in the ICU.Samples were immediately placed in a refrigerator after 2-3 hours before analysis.The levels of 22 kinds of blood amino acids were measured by liquid chromatography-tandem mass spectrometry technology(LC-MS/MS).At the same time,patients,details were recorded,including age,gender,chief complaints for admission,follow-ups of 28-day survivals,APACHE Ⅱ score,MODS score,blood lactate(Lac)levels.The patients were further divided into survivor and non-survivor subgroups based on a 28-day survival.The relationship of the occurrence of septic shock to blood amino acid could be revealed.Changes in amino acid concentrations of 38 septic shock patients,correlations with the APACHE II scores,SOFA scores,Lac levels were studied.Results: On ICU admission,the levels of blood amino acid were within the normal range except the Ser(below normal range).The levels of the different amino acids gradually increased,decreased or fluctuated following ICU admission.1 Median Leu,Val,Met,Cys,Cit concentration decreased from h6 to h0(P < 0.05).Median Phe concentration increased from h6 to h0(P<0.05).Serine level was increased,but below normal range.Blood Met and Cys concentrations decreased from h24 to h0(P < 0.05).Blood Phe,Tyr,Trp,Thr,concentrations increased from h24 to h0(P<0.05).Blood Leu,Val,Phe,Tyr,Trp,Cit,Thr concentrations increased from h24 to h6(P<0.05).Blood Phe,Trp,Thr concentrations increased from d5 to h0(P<0.05).Blood Leu,Cys,Trp,Cit,Thr concentrations increased from d5 to h6(P<0.05).Blood Met and Cys concentrations increased from d5 to h24(P<0.05).2 Compared with survivors,blood concentrations of Leu,Val,Trp,Met,Cys,Glu,Pro in non-survivors were significantly lower(P<0.05)at certain time points.The blood concentrations of Phe,Hcy in non-survivors at certain time points were higher and statistically significant,compared with survivors(P<0.05).3 The Spearman correlation analysis showed a correlation between the scores,Lac and the changes in Met,Trp,Phe,Pro concentrations.The correlation coefficients between the APACHE Ⅱ scores and changes in Met concentration was 0.366(P=0.024).The correlation coefficients between the SOFA scores and changes in Met、Trp concentrations were 0.392(P=0.015),0.330(P=0.043),respectively.The correlation coefficients between the blood Lac and changes in Phe,Pro concentrations were 0.325(P=0.046),-0.322(P=0.048),respectively.Conclusion:Septic shock patients had disorders of amino acid metabolism.The levels of the different amino acids gradually increased,decreased,or fluctuated over time.This study may provide an indicator of the nutritional support of septic shock.There was a correlation among the changes in Met,Trp,Phe,Pro concentrations with the scores,Lac concentration.