Course of lactate, pH and base excess for prediction of mortality in medical intensive care patients

Introduction As base excess had shown superiority over lactate as a prognostic parameter in intensive care unit (ICU) surgical patients we aimed to evaluate course of lactate, base excess and pH for prediction of mortality of medical ICU patients. Materials and methods For lactate, pH and base excess, values at the admission to ICU, at 24 ± 4 hours, maximum or minimum in the first 24 hours and in 24–48 hours after admission were collected from all patients admitted to the Medical ICU of the University Hospital Tübingen between January 2016 until December 2018 (N = 4067 at admission, N = 1715 with ICU treatment > 48 h) and investigated for prediction of in-hospital-mortality. Results Mortality was 22% and significantly correlated with all evaluated parameters. Strongest predictors of mortality determined by ROC were maximum lactate in 24 h (AUROC 0.74, cut off 2.7 mmol/L, hazard ratio of risk group with value > cut off 3.20) and minimum pH in 24 h (AUROC 0.71, cut off 7.31, hazard ratio for risk group 2.94). Kaplan Meier Curves stratified across these cut offs showed early and clear separation. Hazard ratios per standard deviation increase were highest for maximum lactate in 24 h (HR 1.65), minimum base excess in 24 h (HR 1.56) and minimum pH in 24 h (HR 0.75). Conclusion Lactate, pH and base excess were all suitable predictors of mortality in internal ICU patients, with maximum / minimum values in 24 and 24–48 h after admission altogether stronger predictors than values at admission. Base excess and pH were not superior to lactate for prediction of mortality.

The Physiological Profile of Male Professional Soccer Players: The Effect of Playing Division

The purpose of this study was to present the physiological profile of male soccer players who compete in the professional (Division [D] 1, 2, 3) and semi-professional (D4) Greek soccer leagues, and to compare their physiological profile according to playing division. Using 1,095 players (age: 25.2 ± 4.7 years), twelve anthropometric and physiological characteristics (age, height, body mass, BMI, VO2max, velocity of VO2max velocity at ventilatory threshold, maximum heart rate, maximum lactate, squat jump, 35 m sprint and sprinting fatigue index) were assessed. Factorial analysis of variance revealed a significantly (p < 0.05) enhanced physiological profile amongst the professional, compared to semi-professional players, for 10 of the 12 characteristics assessed between divisions. Regarding aerobic parameters, velocity at maximum oxygen uptake was the variable which discriminated professional, from semi-professional players most. With reference to anaerobic parameters, the 35m sprint was the variable which differentiated players between divisions (i.e. D1/D2 vs. D3/D4). Overall, findings in this study present the physiological profile of soccer players within the specified Greek soccer divisions, with differences identified between professional, and semi-professional divisions. These findings suggest that advanced physiological profiles may contribute to a player’s progression to higher divisions of Greek professional soccer.

Myocardial Ischemia During Off-Pump Coronary Artery Bypass Grafting – A Clinical Study

Objective: To evaluate relation among trans-esophageal echocardiography (TEE), biochemical and hemodynamic parameters which could possibly help in early detection of myocardial ischemia. Design: Prospective observational, single centre study. Participants: Patients diagnosed with coronary artery triple vessel disease undergoing Off-pump Coronary Artery Bypass Grafting (OPCAB). Results: Statistically significant changes in Coronary Sinus (CS) pH and lactate levels were observed during lateral wall grafting, as well as the highest proportion of new regional wall motion abnormalities observed which signify the presence of a substantial level of myocardial ischemia during this time. We found a significant rise in HR (Heart Rate) as well as CS lactate following lateral wall grafting which correlated with the other parameters indicating substantial ischemia occurring during grafting of that territory. Maximum lactate clearance was found during anterior wall grafting and minimum after inferior wall grafting. This signifies that maximum lactate accumulates after anterior wall grafting, signifying greater extent of myocardial ischemia. Statistically significant rise in (CVP/RAP) (central venous pressure, right atrial pressure was noted) during grafting of all coronary territories, but the maximal rise was seen at the end of lateral wall grafting, followed by grafting of posterior basal wall. Conclusions: Biochemical changes in form of rise in lactate and fall in CS pH doesn’t occur in absence of obvious hemodynamic derangements. Therefore, it is difficult to detect myocardial ischemia before any hemodynamic instability.

Course of Lactate, pH and Base Excess for Prediction of Mortality in Medical Intensive Care Patients

Introduction: As base excess (BE) had shown superiority over lactate as a prognostic parameter in intensive care unit (ICU) surgical patients we aimed to evaluate course of lactate, base excess and pH for prediction of mortality of medical ICU patients. Materials and Methods: For lactate, pH and base excess, values at the admission to ICU, at 24 ± 4 hours, maximum / minimum in the first 24 hours and in 24 – 48 hours after admission were collected from all patients admitted to the Medical ICU of the University Hospital Tübingen between January 2016 until December 2018 and investigated for prediction of in-hospital-mortality. Results: Mortality in the cohort of 4067 patients was 22 % and significantly correlated with all evaluated parameters. Strongest predictors of mortality determined by ROC were maximum lactate in 24 h (AUROC 0.74, cut off 2.7 mmol/L, hazard ratio of risk group with value > cut off 3.20) and minimum pH in 24 h (AUROC 0.71, cut off 7.31, hazard ratio for risk group 2.94). Kaplan Meier Curves stratified across these cut offs showed early and clear separation. Hazard ratios per standard deviation increase were highest for maximum lactate in 24 h (HR 1.65), minimum base excess in 24 h (HR 1.56) and minimum pH in 24 h (HR 0.75). In multiple logistic regression analysis, age, minimum pH in 24 h, pH at 24 h after admission, maximum lactate in 24 h, maximum lactate in 24 – 48 h, minimum base excess in 24 h and minimum base excess in 24 – 48 h were independent predictors of mortality. Discussion: Lactate, pH and base excess were all suitable predictors of mortality in internal ICU patients, with maximum / minimum values in 24 and 24-48 h after admission altogether stronger predictors than values at admission. Base excess and pH were not superior to lactate for prediction of mortality.

Association between normalized lactate load and mortality in patients with septic shock: an analysis of the MIMIC-III database

Background An index of dynamic lactate change that incorporates both the magnitude of change and the time interval of such change, termed “normalized lactate load,” may reflect the hypoxic burden of septic shock. We aimed to evaluate the association between normalized lactate load and 28-day mortality in adult septic shock patients. Methods Patients with septic shock were identified from the Medical Information Mart for Intensive Care (MIMIC)-III database. Lactate load was defined as the sum of the area under the curve (AUC) of serial lactate levels using the trapezoidal rule, and normalized lactate load was defined as the lactate load divided by time. Receiver-operating characteristic curves were constructed to determine the performance of initial lactate, maximum lactate and normalized lactate load in predicting 28-day mortality. Results A total of 1371 septic shock patients were included, and the 28-day mortality was 39.8%. Non-survivors had significantly higher initial lactate (means ± standard deviations: 3.9 ± 2.9 vs. 2.8 ± 1.7 mmol/L), maximum lactate (5.8 ± 3.8 vs. 4.3 ± 2.2 mmol/L), lactate load (94.3 ± 71.8 vs. 61.1 ± 36.4 mmol·hr./L) and normalized lactate load (3.9 ± 3.0 vs. 2.5 ± 1.5 mmol/L, all p < 0.001). The AUCs of initial lactate, maximum lactate and normalized lactate load were 0.623 (95% confidence interval: 0.596–0.648, with a cut-off value of 4.4 mmol/L), 0.606 (0.580–0.632, with a cut-off value of 2.6 mmol/L) and 0.681 (0.656–0.706, with a cut-off value of 2.6 mmol/L), respectively. The AUC of normalized lactate load was significantly greater than both initial lactate and maximum lactate (all p < 0.001). In the multivariate logistic regression model, normalized lactate load was identified as an independent risk factor for 28-day mortality. Conclusions Normalized lactate load is an independent risk factor for 28-day mortality in adult septic shock patients. Normalized lactate load had better accuracy than both initial and maximum lactate in determining the prognosis of septic shock patients.

The prognostic impact of right ventricular dysfunction in patients with septic cardiomyopathy

Background Sepsis is a systemic condition of profoundly impaired health in which an infection leads to a dysregulated host response, and consecutively causes organ dysfunction, shock, and even death. Septic cardiomyopathy (SCM) is one of the multiple organ dysfunctions. SCM is typically defined as left ventricular (LV) dysfunction, presented by decreased LV ejection fraction (LVEF). However, it remains unclear about the detailed mechanism of cardiac dysfunction. In addition, the prognostic impact of right heart dysfunction in SCM patients has not been fully investigated. Purpose The purpose of this study was to investigate the prognostic impact of right heart dysfunction in patients with SCM. Methods We used the MIMIC-III (Medical Information Mart for Intensive Care III) critical care database, which is a large, freely-available database comprising deidentified health-related data associated with over forty thousand patients who stayed in critical care units of the Beth Israel Deaconess Medical Center between 2001 and 2012. We retrospectively analyzed data of patients with septic shock on admission to intensive care unit (ICU). Septic shock was defined as the presence of any suspected infections, the need for vasopressors, and the lactate level exceeding 2 mmol/L, based on the Sepsis-3 criteria. Patients were performed portable transthoracic echocardiography (TTE) during hospitalization. LVEF and right ventricular (RV) function were determined predominately by visual estimation in the parasternal long-axis view. SCM was defined as having a minimum LVEF of 50% or less during hospitalization. Patients with hyperdynamic motion of LVEF &gt;70% were excluded. Results In total, there were 2254 patients with septic shock. Of these, 604 patients who underwent TTE were enrolled, and 314 patients were diagnosed with SCM. At baseline, age, gender, Sequential Organ Failure Assessment (SOFA) score, maximum lactate levels, and maximum norepinephrine dosage were 70 [59–79] years, 194 males, 13 [11–15], 4.0 [2.7–6.2] mmol/L, and 0.20 [0.10–0.31] mcg/kg/min, respectively. All patients were treated with vasopressors. In Kaplan-Meier survival analysis, patients with SCM had increased 28-day mortality compared with those without SCM (log-rank, p=0.09). In addition, we divided SCM patients into two groups; SCM with and without RV dysfunction. SCM patients with RV dysfunction had significant increased 28-day mortality compared with those without RV dysfunction (log-rank, p=0.01) (Figure). In Cox proportional hazard regression analysis adjusted for age, male sex, SOFA score, and maximum lactate levels, RV dysfunction was an independent determinant of 28-day mortality (hazard ratio, 1.59; 95% confidence interval, 1.03–2.46; p=0.03). Conclusions The presence of RV dysfunction increased 28-day mortality in patients with SCM. It might be useful for predicting the prognosis of SCM to evaluate not only left heart function but also right heart function. Kaplan-Meier survival curves Funding Acknowledgement Type of funding source: None

Course of Lactate, pH and Base Excess for Prediction of Mortality in Medical Intensive Care Patients - A Retrospective Cohort Analysis

Background: We aimed to evaluate the value of lactate, base excess and pH for prediction of mortality in the course of the disease of medical intensive care patients. Methods: For lactate, pH and base excess, values at the admission to intensive care unit (ICU), at 24 ± 4 hours, maximum / minimum in the first 24 hours and in 24 – 48 hours after admission were collected from all patients admitted to the Medical ICU of the University Hospital Tübingen between January 2016 until December 2018 and investigated for prediction of in-hospital-mortality.Results: Mortality in the cohort of 4067 patients was 22 % and significantly correlated with all evaluated parameters. Strongest predictors of mortality determined by ROC were maximum lactate in 24 h (AUROC 0.74, cut off 2.7 mmol/L, hazard ratio of risk group with value > cut off 2.27) and minimum pH in 24 h (AUROC 0.71, cut off 7.43, hazard ratio for risk group 2.94). Kaplan Meier Curves stratified across these cut offs showed early and clear separation. Hazard ratios per standard deviation were highest for maximum lactate in 24 h (HR 1.65), minimum base excess in 24 h (HR 1.56) and minimum pH in 24 h (HR 0.75). In multiple logistic regression analysis, age, minimum pH in 24 h, pH at 24 h after admission, maximum lactate in 24 h, maximum lactate in 24 – 48 h, minimum base excess in 24 h and minimum base excess in 24 – 48 h were independent predictors of mortality. Conclusions: Lactate, pH and base excess were all suitable predictors of mortality in internal ICU patients, with maximum / minimum values in 24 and 24-48 h after admission altogether stronger predictors than values at admission. Base excess and pH were not superior to lactate for prediction of mortality.

Determination of Anaerobic Capacity - Reliability and Validity of Sprint Running Tests

PURPOSE: A number of physiological diagnostics were developed. However, the timeline-related diagnostics of maximal anaerobic glycolytic capacity remain unclear. The objective of this study was to evaluate the reliability and validity of a sprint running test to assess the anaerobic capacity.METHODS: The study was divided into three parts. Sixty-one male (24±4 years, 181.0±4.3 cm; 78.5±5.9 kg) and twelve female (25±3 years, 167.0±0.6 cm, 60.4±5.7 kg) sports students participated in this study. Twenty-five subjects (13 males, 24±2 years, 181.0±0.5 cm, 78.5±5.9 kg; 12 females, 25±3 years, 167.0±0.6 cm, 60.4±5.7 kg) performed incremental step tests at running track and several linear sprints on a running track (LSRT) with different time durations (8, 10, 12, and 14 seconds)(part I) on different days. Twenty-five male subjects (24±3 years, 180.7±6.7 cm, 84.6±8.8 kg) conducted a 10 or 12 second sprint running on a non-motorized treadmill (NMT)(part II). In part III, twenty-three male subjects (24±2 years, 181.4±5.8 cm, 74.5±7.4 kg) ran a 10 second LSRT and NMT on consecutive days. Capillary blood samplings were taken before (Lac_r) and after the sprint running for ten minutes at one minute intervals to find out maximal lactate concentration after exercise and to calculate the maximum lactate production rate (LPR_max).RESULTS: For all parts reliability for LPR_max was proven (Part I: 8 seconds: ICC: <i>r</i>=.89; 10 seconds: ICC: <i>r</i>=.82; 12 seconds: ICC: <i>r</i>=.92; 14 seconds: <i>r</i>=.84, respectively; Part II: 10 seconds: ICC: <i>r</i>=.76; 12 seconds: ICC: <i>r</i>=.79). To analyze validity for LPR_max, Part III was conducted and proven valid (ICC: <i>r</i>=.96, p=.074).CONCLUSIONS: We demonstrate that LSRT and NMT reliably determine anaerobic capacity and can be used as a valid tool for physiological performance diagnostics.

Determination of Anaerobic Capacity - Reliability and Validity of Sprint Running Tests

PURPOSE: A number of physiological diagnostics were developed. However, the timeline-related diagnostics of maximal anaerobic glycolytic capacity remain unclear. The objective of this study was to evaluate the reliability and validity of a sprint running test to assess the anaerobic capacity.METHODS: The study was divided into three parts. Sixty-one male (24±4 years, 181.0±4.3 cm; 78.5±5.9 kg) and twelve female (25±3 years, 167.0±0.6 cm, 60.4±5.7 kg) sports students participated in this study. Twenty-five subjects (13 males, 24±2 years, 181.0±0.5 cm, 78.5±5.9 kg; 12 females, 25±3 years, 167.0±0.6 cm, 60.4±5.7 kg) performed incremental step tests at running track and several linear sprints on a running track (LSRT) with different time durations (8, 10, 12, and 14 seconds)(part I) on different days. Twenty-five male subjects (24±3 years, 180.7±6.7 cm, 84.6±8.8 kg) conducted a 10 or 12 second sprint running on a non-motorized treadmill (NMT)(part II). In part III, twenty-three male subjects (24±2 years, 181.4±5.8 cm, 74.5±7.4 kg) ran a 10 second LSRT and NMT on consecutive days. Capillary blood samplings were taken before (Lac_r) and after the sprint running for ten minutes at one minute intervals to find out maximal lactate concentration after exercise and to calculate the maximum lactate production rate (LPR_max).RESULTS: For all parts reliability for LPR_max was proven (Part I: 8 seconds: ICC: <i>r</i>=.89; 10 seconds: ICC: <i>r</i>=.82; 12 seconds: ICC: <i>r</i>=.92; 14 seconds: <i>r</i>=.84, respectively; Part II: 10 seconds: ICC: <i>r</i>=.76; 12 seconds: ICC: <i>r</i>=.79). To analyze validity for LPR_max, Part III was conducted and proven valid (ICC: <i>r</i>=.96, p=.074).CONCLUSIONS: We demonstrate that LSRT and NMT reliably determine anaerobic capacity and can be used as a valid tool for physiological performance diagnostics.

VO2 Steady State at and Just Above Maximum Lactate Steady State Intensity

Over recent decades the association between metabolic and gas exchange parameters during exercise has become evident. Different “thresholds” (such as lactate thresholds, critical power, EMG thresholds) and intensity domains appear to be linked to an upper limit of oxygen uptake steady state (V̇O2SS). The aim of this study was to investigate whether MLSS is associated with the upper limit for a V̇O2SS. Forty-five subjects underwent one incremental test and 4–6 30-minute MLSS tests on a cycle ergometer. A three-component model was used to describe V̇O2 response at PMLSS and just above PMLSS+1. To evaluate the results, breath-by-breath V̇O2 and lactate (LA) values were analyzed using the intraclass correlation coefficient (ICC), increasing (k-) values and the Wilcoxon test. According to the calculated k-values of LA and VO2 at PMLSS and PMLSS+1, no significant increase of VO2 occurred during both intensities (PMLSS and PMLSS+1) from minute 10 to minute 30, confirming the existence of a V̇O2SS. Additionally, the ICC of 0.94 confirmed high accordance of the VO2 kinetics at both intensities (PMLSS and PMLSS+1). This study shows that power output at MLSS workload does not represent an accurate cut for an upper limit of V̇O2SS.