Risk Factors And Short-term Prognosis Of Acute Kidney Injury In The Very Elderly Patients

PartⅠRisk Factors and Short-term Prognosis of Acute Kidney Injuryin the Very Elderly PatientsObjective To explore the risk factors and short-term outcome of acute kidneyinjury (AKI) in the very elderly patients.Methods A total of232elderly AKI patients were enrolled. They were dividedinto two groups according to their outcome within28days and from the29thday to the end of3months after AKI, respectively. Their clinical data wereanalyzed to explore the risk factors and their effects on the outcome of AKI.Results There were215males and17females with an average age of(86.7±5.3) years.38cases (16.4%) died within28days after AKI, and19cases(9.8%) died from the29th day to the end of3months after AKI. Infection(43.1%) was the major cause of AKI. The other causes of AKI includedhypovolemia (19%), use of nephrotoxic drugs (16.8%) and cardiovascularevents (15.1%), respectively. Logistic regression analysis revealed that low bodymass index (BMI), oliguria, mechanical ventilation, hypoalbuminemia, and peaklevel of serum creatinine (Scr>246.5μmol/L) were the prognostic factors of AKIin those patients died within28days after AKI (P<0.05). Low BMI,hypoalbuminemia, and high level of blood urea nitrogen (BUN) were theprognostic factors of AKI in those patients died from the29th day to the end of3months after AKI (P<0.05).Conclusions Infection, hypovolemia, use of nephrotoxic drugs andcardiovascular events are common causes of AKI in the very elderly patients.Low BMI, oliguria, mechanical ventilation, hypoalbuminemia, high level ofBUN, and peak level of Scr (>246.5μmol/L) are the prognostic factors of AKI inthe very elderly patients. Part ⅡThe Incidence and Risk Factors of Acute Kidney Injury in theVery Elderly Patients with Mechanical VentilationObjective To explore the incidence, pathogenetic and risk factors of acutekidney injury (AKI) in the very elderly patients with mechanical ventilation(MV).Methods A total of260elderly patients with MV were enrolled. Their clinicaldata were analyzed to explore the incidence and risk factors of AKI in the veryelderly patients after MV.Results The average age of the patients was (88.9±5) years.125cases (48.1%)suffered from AKI which emerged at a mean time of (1.6±0.7) days after MV.The history of chronic kidney disease (CKD,66.4%vs51.1%, P=0.012) anddiabetes (51.2%vs38.5%, P=0.040) in the patients with AKI (AKI group) werehigher than that in the patients without AKI (Non-AKI group). Compared withthe Non-AKI group, lower level of PaO2(59.7±12.8vs63.6±14.1, P=0.031),lower level of oxygen index (PaO2/FiO2,122.5±42vs145.7±46, P=0.000), higherlevel of hemoglobin (105±23vs100±17, P=0.046) and hyperglycemic (10.2±4.1vs8.8±3.7, P=0.004) were found in AKI group. The incidence of AKI was higherwhen the patients using higher level of positive end-expiratory pressure(PEEP)≥4cmH2O. Logistic regression analysis showed that the history of CKD(OR=1.964), hyperglycemia (OR=1.076), the lower level of PaO2/FiO2(OR=2.142) and using higher level of PEEP (≥4cmH2O, OR=0.990) were the riskfactors of the prognosis of AKI in those patients with MV (P<0.05).Conclusions The incidence of AKI in the very elderly patients with MV was48.1%. The history of CKD, hyperglycemia, low level of PaO2/FiO2and usinghigher level of PEEP (≥4cmH2O) were the risk factors of AKI in the very elderlypatients with MV. Part ⅢRisk Factors and Short-term Prognosis in the Patientsof Advanced Age with Mechanical VentilationObjective To explore the risk factors and short-term outcome in the veryelderly patients with mechanical ventilation (MV).Methods A total of270elderly patients with MV were enrolled. They weredivided into two groups according to their outcome within28days and from the29th day to the end of3months after MV, respectively. Their clinical data wereanalyzed to explore the risk factors and their effects on the outcome in thepatients after MV.Results The average age of the patients was (89±4.8) years. Lung infection(70.7%) was the major cause of MV. The other causes included acute heartfailure (10.7%), chronic obstructive pulmonary disease with acute exacerbation(AECOPD,7.8%), respectively.86cases (31.9%) died within28days after MV,and40cases (21.7%) died from the29th day to the end of3months after MV.Logistic regression analysis revealed that low level of oxygenation index(PaO2/FiO2), low level of serum prealbumin (Pre-Alb), high level of blood ureanitrogen (BUN), high level of serum creatinine (Scr>165.2μmol/L), usingpositive end-expiratory pressure (PEEP) were the prognostic factors in thosepatients died within28days after MV (P<0.05). The history of chronic kidneydisease (CKD), C-reactive protein (CRP) were the prognostic factors in thosepatients died from the29th day to the end of3months after MV (P<0.05).Conclusions Lung infection, acute heart failure and AECOPD are commoncauses of MV therapy in the very elderly patients. The history of CKD, lowlevel of PaO2/FiO2, low level of Pre-Alb, CRP, high level of BUN, high level ofScr (>165.2μmol/L) and using PEEP are the prognostic factors in the veryelderly patients with MV.