The usefulness of perioperative lactate blood levels in patients undergoing heart valve surgery

Association between lactate/albumin ratio and mortality in patients with heart failure after myocardial infarction

AIMS

Lactate/albumin ratio (L/A) is a recognized prognostic index of patients with heart failure (HF) after myocardial infarction (MI). We aim to evaluate the prognostic value of L/A ratio in predicting in-hospital mortality for those patients.

METHODS AND RESULTS

We enrolled qualified patients from Medical Information Mart for Intensive Care IV database for retrospective study. A receiver operating characteristic (ROC) curve of the subjects was applied to determine the predicted value and the best cut-off value of L/A on admission. Univariate/multivariate Cox regression analysis and restricted cubic splines (RCS) were performed to identify the association between hospital admission and hospital mortality. The Kaplan-Meier (KM) method was used to draw the survival curve of the two groups with different L/A levels at admission. L/A values at admission were significantly higher in the death groups than the survival groups [1.36 (1.20) vs. 0.62 (0.36), P < 0.05], and area under the ROC curve [0.780 (95% confidence interval, 0.772-0.827)] was better than other indicators, and the best the cut-off value was 0.671. Data of Cox regression analysis showed that higher L/A value supposed to be an independent risk factor for in-hospital mortality. RCS analysis showed evidence of an increasing trend and a non-linear relationship between L/A and in-hospital mortality (P value was non-linear <0.05). KM survival curves were significantly lower in the high L/A group than the low L/A group (P < 0.001), and the former group had an increased risk of in-hospital mortality compared with the latter one (log rank P < 0.001).

CONCLUSIONS

Elevated L/A ratio on admission is an independent predictor of high in-hospital mortality in post-MI heart failure patients, which proved to be better than lactate, Sequential Organ Failure Assessment score and other related indicators.

Sufentanil: a risk factor for lactic acidosis in patients after heart valve surgery

Backgrounds

Hyperlactatemia is a common metabolic disorder after cardiac surgery with cardiopulmonary bypass. Epinephrine use has been identified as a potential cause of increased lactate levels after cardiac surgery. Stress can lead to an increase in catecholamines, mainly epinephrine, in the body. Exogenous epinephrine causes hyperlactatemia, whereas endogenous epinephrine released by stress may have the same effect. Opioids are the most effective anesthetics to suppress the stress response in the body. The authors sought to provide evidence through a retrospective data analysis that helps investigate the relationship between intraoperative opioid dosage and postoperative lactic acidosis after cardiac surgery.

Methods

The clinical data of 215 patients who underwent valvular heart surgery with cardiopulmonary bypass from July 2016 to July 2019 were analyzed retrospectively. Blood lactate levels were measured at 0.1 h, 2 h, 4 h, and 8 h after surgery. Patients with continuous increases in lactate levels and lactate levels exceeding 5 mmol/L at two or more time points were included in the lactic acidosis group, whereas the other patients were included in the control group. First, univariate correlation analysis was used to identify parameters that were significantly different between the two groups, and then multivariate regression analysis was conducted to elucidate the independent risk factors for lactic acidosis. Fifty-one pairs of patients were screened by propensity score matching analysis (PSM). Then, lactic acid levels at four time points in both groups were analyzed by repeated measures ANOVA.

Results

he EF (heart ejection fraction) (OR = 0.94, P = 0.003), aortic occlusion time (OR = 10.17, P < 0.001) and relative infusion rate (OR = 2.23, P = 0.01) of sufentanil was an independent risk factor for lactic acidosis after valvular heart surgery. The patients were further divided into two groups with the mean sufentanil infusion rate as the reference point. The data were filtered with PSM (Propensity Score Matching). Lactic acid values in both groups peaked at 4 h after surgery and then declined. The rate of lactic acid decline was significantly faster in the group with a higher sufentanil dosage than in the lower group. The difference was statistically significant (P < 0.05). There was also a significant difference in lactic acid levels at the four time points (0.1 h, 2 h, 4 h and 8 h after surgery) in both groups (P < 0.001).

Conclusion

The inadequate intraoperative infusion rate of sufentanil is an independent risk factor for lactic acidosis after heart valve surgery. The possibility of lactic acidosis caused by this factor after cardiac surgery should be considered, which is helpful for postoperative patient management.

Development and validation of a nomogram model for early postoperative hyperlactatemia in patients undergoing cardiac surgery

Background

Postoperative hyperlactatemia (POHL) is common in patients undergoing cardiac surgery, associated with adverse outcomes. The aim of this study was to identify predictors for POHL after cardiac surgery and to develop and validate a predictive model.

Methods

Adult patients who underwent open heart surgery at our institution between 2016 and 2019 were retrospectively included. The patients were randomly divided into training and validation groups at a 2:1 ratio. Multivariate logistic regression was performed to identify independent predictors for POHL in the training set. A nomogram was then constructed and was validated in the validation set.

Results

POHL developed in 713 of the 5,323 patients (13.4%). The mortality rate was higher in patients with POHL compared with patients without that (9.5% vs. 2.1%, P<0.001). Age, white blood cell (WBC) count, left ventricular ejection fraction, renal insufficiency, cardiac surgery history, red blood cell (RBC) transfusion, and cardiopulmonary bypass (CPB) time were identified as independent risk factors. The nomogram based on these predictors indicated good discrimination in both the training (c-index: 0.787) and validation (c-index: 0.820) sets. The calibration was reasonable by both visual inspection and goodness-of-fit test. The decision and clinical impact curves demonstrated good clinical utility.

Conclusions

We identified 7 independent risk factors and derived a prediction model for POHL in patients undergoing cardiac surgery. The model may contribute significantly to early risk assessment and clinical intervention.

Red Cell Distribution Width as a Prognostic Factor and Its Comparison with Lactate in Patients with Sepsis

Sepsis remains the leading cause of death in critically ill patients. Thus, regular measurement of lactate levels has been proposed in sepsis guidelines. Elevated red cell distribution width (RDW) is associated with mortality risk in patients with sepsis. This study aimed to investigate the association between RDW and the risk of other adverse outcomes in patients with sepsis and to compare the mortality discriminative ability between lactate and RDW levels. This is a single-centered, retrospective, case-control study that included 504 adult patients with sepsis in the emergency department between 1 January 2020 and 31 December 2020. Eligible patients were divided into normal (RDW ≤ 14.5%) and high (RDW > 14.5%) groups. The baseline characteristics and adverse outcomes were recorded and compared. Compared with the normal RDW group, the patients in the high RDW group had a significantly higher rate of ICU admission (48.8% vs. 32.4%, p = 0.03), septic shock (39.2% vs. 23.5%, p < 0.01), and 30-day in-hospital mortality (32.0% vs. 20.7%, p < 0.01). Furthermore, the RDW (area under curve (AUC) = 0.71) had superior mortality discriminative ability compared to lactate (AUC = 0.63) levels (p = 0.02). Clinicians could rely on this simple and rapid parameter for risk stratification to initiate prompt treatment for patients with sepsis.