Visualizing the dynamic mechanical power and time burden of mechanical ventilation patients: an analysis of the MIMIC-IV database.

BACKGROUND: Limiting driving pressure and mechanical power is associated with reduced mortality risk in both patients with and without acute respiratory distress syndrome. However, it is still poorly understood how the intensity of mechanical ventilation and its corresponding duration impact the risk of mortality. METHODS: Critically ill patients who received mechanical ventilation were identified from the Medical Information Mart for Intensive Care (MIMIC)-IV database. A visualization method was developed by calculating the odds ratio of survival for all combinations of ventilation duration and intensity to assess the relationship between the intensity and duration of mechanical ventilation and the mortality risk. RESULTS: A total of 6251 patients were included. The color-coded plot demonstrates the intuitive concept that episodes of higher dynamic mechanical power can only be tolerated for shorter durations. The three fitting contour lines represent 0%, 10%, and 20% increments in the mortality risk, respectively, and exhibit an exponential pattern: higher dynamic mechanical power is associated with an increased mortality risk with shorter exposure durations. CONCLUSIONS: Cumulative exposure to higher intensities and/or longer duration of mechanical ventilation is associated with worse outcomes. Considering both the intensity and duration of mechanical ventilation may help evaluate patient outcomes and guide adjustments in mechanical ventilation to minimize harmful exposure.

The magnitude, but not the duration of elevated central venous pressure is associated with mortality in sepsis patients: An analysis of the MIMIC-IV database.

BACKGROUND: It is unclear whether the magnitude and duration of elevated central venous pressure (ECVP) greater than ten mmHg has the same impact on mortality in sepsis patients. METHODS: Critically ill patients with sepsis were identified from the Medical Information Mart for Intensive Care (MIMIC)-IV database. The duration and the magnitude of ECVP were calculated. Normalized ECVP load was defined as the ECVP load (the sum of ECVP value times its duration) divided by the total duration of ECVP. The primary endpoint was 28-day mortality. Kaplan-Meier survival analysis was used to compare survival between patients with high or low normalized ECVP load. RESULTS: A total of 1071 sepsis patients were included. Higher normalized ECVP load was associated with higher mortality rate; in contrast, the duration of ECVP was not associated with mortality. A linear relationship between normalized ECVP load and mortality was identified. Patients with higher normalized ECVP load had less urine output and more positive fluid balance. CONCLUSION: The magnitude, but not the duration of ECVP, is associated with mortality in sepsis patients. ECVP should be considered as a valuable and easily accessible safety parameter during fluid resuscitation.

Increased normalized lactate load is associated with higher mortality in both sepsis and non-sepsis patients: an analysis of the MIMIC-IV database.

BACKGROUND: The present study aimed to evaluate the association between normalized lactate load, an index that incorporates the magnitude of change and the time interval of such evolution of lactate, and 28-day mortality in sepsis and non-sepsis patients. We also compared the accuracy of normalized lactate load in predicting mortality between these two populations. METHODS: Data were extracted from the Medical Information Mart for Intensive Care (MIMIC)-IV database. We defined lactate load as the sum of the area under the lactate concentration curve; we also defined normalized lactate load as the lactate load divided by time. The performance of maximum lactate, mean lactate and normalized lactate load in predicting 28-day mortality in sepsis and non-sepsis patients were compared by receiver-operating characteristic curves analysis. RESULTS: A total of 21,333 patients were included (4219 sepsis and 17,114 non-sepsis patients). Non-survivors had significantly higher normalized lactate load than survivors in sepsis and non-sepsis patients. The maximum lactate, mean lactate, and normalized lactate load AUCs were significantly greater in sepsis patients than in non-sepsis patients. Normalized lactate load had the greatest AUCs in predicting 28-day mortality in both sepsis and non-sepsis patients. Sensitivity analysis showed that the AUC of normalized lactate load increased in non-sepsis patients when more lactate measurement was obtained, but it was not improved in sepsis patients. CONCLUSIONS: Normalized lactate load has the strongest predictive power compared with maximum or mean lactate in both sepsis and non-sepsis patients. The accuracy of normalized lactate load in predicting mortality is better in sepsis patients than in non-sepsis patients.

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.

[Risk factors for acute respiratory distress syndrome following surgeries for pediatric critical and complex congenital heart disease].

OBJECTIVE: To explore the risk factors for acute respiratory distress syndrome (ARDS) in children receiving surgeries for critical and complex congenital heart disease (CCHD). METHODS: According to the 2011's Berlin definition of ARDS, the clinical data were collected from 75 children without ARDS (group I) and 80 children with ARDS (group II) following surgeries for CCHD performed in the Department of Cardiac Surgery of our hospital from January, 2009 to May, 2014. Univariate analyses and logistic regression were used to analyze the risk factors contributing to the occurrence of ARDS following the surgeries. RESULTS: In the 80 patients who developed ARDS postoperatively in group II, 27 had mild ARDS, 25 had moderate ARDS, and 28 had severe ARDS; death occurred in 17 (21%) cases. Univariate analyses showed that 23 parameters were significantly different between groups I and II (P<0.05), including weight; preoperative PCO2, left ventricular ejection fraction, pulmonary artery pressure, pulmonary infection, and coagulation abnormalities; early postoperative serum globulin; intraoperative aortic cross clamp (ACC) time; cardiopulmonary bypass (CPB) time; operation time; blood loss and blood transfusion amount intraoperatively and during the first 8 h after operation; lactic acid level immediately after the operation and its maximum increasing rate within 24 h postoperatively; postoperative serum levels of albumin and creatinine; serum levels of B-type natriuretic peptide, procalcitonin, C-reactive protein, and prealbumin 24 h after operation; and age. Logistic regression analyses showed that intraoperative ACC time, CPB time, the maximum increasing rate of lactic acid within 24 h after operation, serum procalcitonin 24 h after operation and intraoperative blood loss were independent risk factors for postoperative ARDS. CONCLUSION: The risk factors of ARDS identified in these children can predict the occurrence of ARDS following the surgeries and timely interventions can improve the success rate in treatment of postoperative ARDS in children with CCHD.

Better short-term efficacy of treating severe flail chest with internal fixation surgery compared with conservative treatments.

BACKGROUND: The objective of the study is to provide evidence for selecting the best treatment approach for severe flail chest by comparing surgical and conservative treatments. METHODS: This is a retrospective study in which 32 patients with severe flail chest were treated in the Fujian Provincial Hospital (China) between July 2007 and July 2012 with surgical internal rib fixation (n = 17) or conservative treatments (n = 15). Mechanical ventilation time, intensive care unit (ICU) stay time, pulmonary infection, antibiotic treatment duration, acute physiology and chronic health evaluation II (APACHE II) scores 7 and 14 days after trauma, rate of tracheostomy, and rate of endotracheal re-intubation were compared. RESULTS: One patient died in the conservative treatment group. Better short-term outcomes were observed in the surgery group, such as total mechanical ventilation time (10.5 ± 3.7 vs. 13.7 ± 4.4 days, P = 0.03), ICU stay (15.9 ± 5.0 vs. 19.6 ± 5.0 days, P = 0.05), pulmonary infection rate (58.8 % vs. 93.3 %, P = 0.02), and APACHE II scores on the 14th day (6.5 ± 3.8 vs. 10.1 ± 4.7, P = 0.02). No difference was observed in the therapeutic time of antibiotics, rate of tracheostomy, and the rate of endotracheal re-intubation between the two groups. CONCLUSIONS: Results suggest that internal fixation surgery resulted in better outcomes in the management of severe flail chest compared with conservative treatments.