Influence of transcutaneous oximetry on septic shock-associated acute kidney injury

Abstract

Objective To explore the influence of transcutaneous oximetry on septic shock-associated acute kidney injury(AKI) in intensive care unit (ICU). Methods Forty-nine patients with septic shock admitted in the ICU of Wuxi People’s Hospital Affiliated to Nanjing Medical University were enrolled from January 2013 to December 2015. The 10 min oxygen challenge test was conducted using transcutaneous oximetry just before(0 h) and 6 h after initiation of fluid resuscitation, and 10 min oxygen challenge test data (10 min OCT) at 0 h and 6 h were then calculated, respectively. The enrolled patients were divided into low 10 min OCT group (10 min OCT< 66 mmHg, L group) or high 10 min OCT group (10 min OCT≥66 mmHg, H group) according to the 10 min OCT value at 6 h. The hemodynamic variables[mean arterial pressure(MAP), central venous pressure(CVP)], oxygen metabolism indexes[central venous oxygen saturation (ScvO2 ), arterial lactate(Lac)], dose of vasoactive agents, 10 min OCT at 0 h and 6 h were recorded. APACHEⅡ score, incidence and severity of septic shock-associated AKI, frequency of CRRT, ICU mortality and 28 d mortality were compared between groups using SPSS 22.0 software, risk factors associated with prognosis were analyzed using COX regression model. Results There were 27 cases in L group and 22 cases in H group. The MAP, CVP, ScvO2, lactate level and dose of vasoactive agents were comparable between groups at 0 h or 6 h(P>0.05), while 10 min OCT at 6 h was higher in H group than that in L group[(77.6±18.5)mmHg vs.(51.3±21.6)mmHg, P<0.05]. The incidence of septic shock-associated AKI(77.8% vs.50.0%, P<0.05), proportion of phase 3 AKI(44.4% vs.22.7%, P<0.05) and frequency of CRRT (48.1% vs.22.7%, P<0.05) was higher in L group than those in H group, and similarly were the ICU mortality(51.8% vs.22.7%, P<0.05) and 28 d mortality(63.0% vs.31.8%, P<0.05). Therefore, the 6 h 10 min OCT≥66 mmHg was a protective factor to improve the ICU mortality(RR=0.01, 95%CI: 0.001-0.39, P<0.05) and 28 d mortality(RR=0.01, 95%CI: 0.001-0.27, P<0.05) in patients with septic shock-associated AKI. Conclusions 10 min OCT imposes substantial influence on the incidence, severity and prognosis of patients with septic shock-associated AKI, oxygen challenge test could improve the treatment of septic shock-associated AKI. Key words: Transcutaneous oximetry; Oxygen challenge test; Septic shock; Acute kidney injury; Incidence; Prognosis