Effectiveness of sodium bicarbonate infusion on mortality for elderly septic patients with acute metabolic acidosis

Abstract

Objective: This study aimed to explore the effectiveness of sodium bicarbonate (SB) infusion on mortality in elderly septic patients with acute metabolic acidosis (MA) and in other subgroups.Methods: Retrospective analysis of a large ICU database (MIMIC-IV) was performed. Elderly septic patients with acute MA were identified from MIMIC-IV. Propensity score analysis (PSA) was performed to explain for the baseline differences in the probability to receive SB or not. The marginal structural Cox model (MSCM) was developed to adjust for both baseline and time-varying confounding variables. The primary outcome was the ICU and hospital mortality.Results: A total of 869 elderly septic patients with acute MA were identified in this study, including 361 in the SB group and 508 in the non-SB group. In the PSA, SB infusion was not associated with reduced ICU (HR 0.82, 95% CI 0.62–1.10; p = 0.19) or hospital (HR 0.94, 95% CI 0.74–1.19; p = 0.60) mortality in overall elderly septic patients with acute MA. In the subgroup of severe metabolic acidosis, SB infusion could not improve the ICU (HR 0.82, 95% CI 0.62–1.10; p =0.19) and hospital (HR 0.94, 95% CI 0.74–1.19; p =0.60) mortality on elderly septic patients. However, In the subgroup of moderate metabolic acidosis, SB infusion could be found associated with improved ICU (HR 0.64, 95% CI 0.43–0.95; p <0.05) and hospital (HR 0.70, 95% CI 0.50–0.99; p <0.05) survival in elderly septic patients. In the MSCM, the results were similar with PSA.Conclusion: SB infusion could improve both ICU and hospital survival for elderly septic patients with acute metabolic acidosis.

Sodium bicarbonate for the treatment of severe metabolic acidosis with moderate or severe acute kidney injury in the critically ill: protocol for a randomised clinical trial (BICARICU-2)

“… 19 In a single centre retrospective study using the open access MIMIC-3 database, 869 patients older than 60 years old with sepsis and moderate metabolic acidosis (pH≤7.3 and bicarbonataemia less than 20 mmol/L) were evaluated according to whether they received sodium bicarbonate or not within 48 hours after the ICU admission. 12 Both ICU and hospital mortality were significantly reduced in the subgroup of patients with moderate metabolic acidemia (7.2<pH<7.3) treated with sodium bicarbonate. Using the same MIMIC-3 database and moderate acidemia (pH<7.30), Wang et al suggested that sodium bicarbonate was not associated with survival and that sodium bicarbonate might be associated with worsening organ failure score in a subset of patients with unchanged or deteriorating haemodynamics before sodium bicarbonate infusion.…”

“…After adjusting for confounders, sodium bicarbonate was associated with higher mean arterial pressure at 6 hours among the patients with vasopressors dependency but not with mortality 19. In a single centre retrospective study using the open access MIMIC-3 database, 869 patients older than 60 years old with sepsis and moderate metabolic acidosis (pH≤7.3 and bicarbonataemia less than 20 mmol/L) were evaluated according to whether they received sodium bicarbonate or not within 48 hours after the ICU admission 12. Both ICU and hospital mortality were significantly reduced in the subgroup of patients with moderate metabolic acidemia (7.2<pH<7.3) treated with sodium bicarbonate.…”

“…Although the BICARICU trial suggested a room for sodium bicarbonate in a subgroup of patients, this indication remains controversial and highly debated in the literature especially about the potential side effects of sodium bicarbonate infusion on homeostasis and the potential benefit of acidemia on cells metabolism and oxygenation. [9][10][11][12] Recognising the equipoise between sodium bicarbonate and no sodium bicarbonate in this subpopulation, we have chosen to conduct a further investigation into the use of sodium bicarbonate infusion in critically ill patients presenting with both severe acidemia and moderate-to-severe acute kidney injury (AKI).…”

“…However, in a prespecified stratum of patients with moderate-to-severe kidney injury, the infusion of sodium bicarbonate in comparison with no sodium bicarbonate infusion was associated with reduced rate of mortality from enrolment to day 28 between the control group and bicarbonate group: 63% (95% CI 52% to 72%) vs 46% (95% CI 35% to 55%); p=0.02833 as well as less renal replacement therapy requirement ((66/90 (73%) vs 47/92 (51%), absolute difference: −22.2 (95% CI –36 to –8.5), p=0.002). Although the BICARICU trial suggested a room for sodium bicarbonate in a subgroup of patients, this indication remains controversial and highly debated in the literature especially about the potential side effects of sodium bicarbonate infusion on homeostasis and the potential benefit of acidemia on cells metabolism and oxygenation 9–12. Recognising the equipoise between sodium bicarbonate and no sodium bicarbonate in this subpopulation, we have chosen to conduct a further investigation into the use of sodium bicarbonate infusion in critically ill patients presenting with both severe acidemia and moderate-to-severe acute kidney injury (AKI).…”

Utilization of interpretable machine learning model to forecast the risk of major adverse kidney events in elderly patients in critical care

“…The presence of metabolic acidosis, as indicated by low HCO3- levels, may reflect tubular interstitial disease and poor renal function, leading to an increased risk of AKI [ 41 ]. Previous retrospective cohort studies have confirmed this association, and the use of sodium bicarbonate infusion has been explored as a potential intervention to improve kidney and survival outcomes [ 25 , 42 ].…”