This thesis contributes to the quest to better understand, monitor and predict outcomes of critically ill patients in circulatory shock who are at risk of oxygen deficits in tissues and cells. In... Show moreThis thesis contributes to the quest to better understand, monitor and predict outcomes of critically ill patients in circulatory shock who are at risk of oxygen deficits in tissues and cells. In the studies performed, we explored hypoxia severity in tissue and cells in addition to the commonly used parameters for perfusion and oxygenation in critically ill patients. We investigated the added predictive value of lactate and lactate clearance to the Acute Physiology and Chronic Health Evaluation IV model for predicting in-hospital mortality in critically ill patients with sepsis. We subsequently validated the findings in the Medical Information Mart for Intensive Care cohort. We also studied characteristics of the recently developed protoporphyrin IX-triple state lifetime technique. This measures mitochondrial oxygenation tension (mitoPO2) in vivo at the bedside. We examined the variability of the mitoPO2 measurements between and within healthy subjects. Next, we similarly assessed mitoPO2 values at various timepoints in critically ill patients with anemia before and after red blood cell transfusions and examined the associations between mitoPO2 and other parameters of critical illness and of tissue oxygenation and perfusion in critically ill patients. Show less
Slingerland-Boot, R.; Rooijakkers, E.; Koekkoek, K.; Blokland, D. van; Arbous, S.; Zanten, A. van 2023
BackgroundNormocaloric vs. calorie-restricted feeding in Intensive Care Unit (ICU) patients with refeeding hypophosphatemia (RH) is associated with increased mortality rates. Until now, only total... Show moreBackgroundNormocaloric vs. calorie-restricted feeding in Intensive Care Unit (ICU) patients with refeeding hypophosphatemia (RH) is associated with increased mortality rates. Until now, only total energy provision has been studied. Data on individual macronutrients (proteins, lipids, and carbohydrates) and clinical outcomes are lacking. This study evaluates associations between macronutrient intake among RH patients during the first week of ICU admission and clinical outcomes.MethodsA single-centre retrospective observational cohort study was conducted among prolonged mechanically ventilated RH ICU patients. The primary outcome was the association of separate macronutrient intakes during the first week of ICU admission with 6-month mortality, adjusted for relevant variables. Other parameters included ICU-, hospital- and 3-month mortality, mechanical ventilation duration and length of ICU and hospital stay. Macronutrient intakes were subsequently analyzed during day 1–3 and day 4–7 of ICU admission.ResultsIn total, 178 RH patients were included. Six-month all-cause mortality was 29.8%. Higher protein intake during days 1–3 of ICU admission (>0.71 g/kg∗day; HR 2.224, 95%CI 1.261–3.923, p = 0.006), higher age (HR 1.040, 95%CI 1.015–1.066, p = 0.002) and higher APACHE II scores on ICU admission (HR 1.086, 95%CI 1.034–1.140, p = 0.001) were associated with increased 6-month mortality. No differences in other outcomes were observed.ConclusionHigh protein - not carbohydrate or lipid - intake during the first three days of ICU admission in patients with RH is associated with increased 6-month mortality, but not short-term outcomes. We hypothesize a time-dependent and dose–response relationship between protein intake and mortality in refeeding hypophosphatemia ICU patients, although additional (randomized controlled) studies are needed to confirm this hypothesis. Show less
Background: Early and appropriate antibiotic dosing is associated with improved clinical outcomes in critically ill patients, yet target attainment remains a challenge. Traditional antibiotic... Show moreBackground: Early and appropriate antibiotic dosing is associated with improved clinical outcomes in critically ill patients, yet target attainment remains a challenge. Traditional antibiotic dosing is not suitable in critically ill patients, since these patients undergo physiological alterations that strongly affect antibiotic exposure. For beta-lactam antibiotics, the unbound plasma concentrations above at least one to four times the minimal inhibitory concentration (MIC) for 100% of the dosing interval (100%integral T > 1-4xMIC) have been proposed as pharmacodynamic targets (PDTs) to maximize bacteriological and clinical responses. The objectives of this study are to describe the PDT attainment in critically ill patients and to identify risk factors for target non-attainment.Methods: This prospective observational study was performed in two ICUs in the Netherlands. We enrolled adult patients treated with the following beta-lactam antibiotics: amoxicillin (with or without clavulanic acid), cefotaxime, ceftazidime, ceftriaxone, cefuroxime, and meropenem. Based on five samples within a dosing interval at day 2 of therapy, the time unbound concentrations above the epidemiological cut-off (integral T > MICECOFF and integral T > 4xMIC(ECOFF)) were determined. Secondary endpoints were estimated multivariate binomial and binary logistic regression models, for examining the association of PDT attainment with patient characteristics and clinical outcomes.Results: A total of 147 patients were included, of whom 63.3% achieved PDT of 100% integral T > MICECOFF and 36.7% achieved 100% integral T > 4xMIC(ECOFF). Regression analysis identified male gender, estimated glomerular filtration rate (eGFR) >= 90 mL/min/1.73 m(2), and high body mass index (BMI) as risk factors for target non-attainment. Use of continuous renal replacement therapy (CRRT) and high serum urea significantly increased the probability of target attainment. In addition, we found a significant association between the 100% integral T > MICECOFF target attainment and ICU length of stay (LOS), but no significant correlation was found for the 30-day survival.Conclusions Traditional beta-lactam dosing results in low target attainment in the majority of critically ill patients. Male gender, high BMI, and high eGFR were significant risk factors for target non-attainment. These predictors, together with therapeutic drug monitoring, may help ICU clinicians in optimizing beta-lactam dosing in critically ill patients. Show less
Purpose To develop and validate a population pharmacokinetic model of ciprofloxacin intravenously in critically ill patients, and determine target attainment to provide guidance for more effective... Show morePurpose To develop and validate a population pharmacokinetic model of ciprofloxacin intravenously in critically ill patients, and determine target attainment to provide guidance for more effective regimens. Methods Non-linear mixed-effects modelling was used for the model development and covariate analysis. Target attainment of an integral AUC(0-24)/MIC >= 100 for different MICs was calculated for standard dosing regimens. Monte Carlo simulations were performed to define the probability of target attainment (PTA) of several dosing regimens. Results A total of 204 blood samples were collected from 42 ICU patients treated with ciprofloxacin 400-1200 mg/day, with median values for age of 66 years, APACHE II score of 22, BMI of 26 kg/m(2), and eGFR of 58.5 mL/min/1.73 m(2). The median integral AUC(0-24) and integral C-max were 29.9 mg center dot h/L and 3.1 mg/L, respectively. Ciprofloxacin pharmacokinetics were best described by a two-compartment model. We did not find any significant covariate to add to the structural model. The proportion of patients achieving the target integral AUC(0-24)/MIC >= 100 were 61.9% and 16.7% with MICs of 0.25 and 0.5 mg/L, respectively. Results of the PTA simulations suggest that a dose of >= 1200 mg/day is needed to achieve sufficient integral AUC(0-24)/MIC ratios. Conclusions The model described the pharmacokinetics of ciprofloxacin in ICU patients adequately. No significant covariates were found and high inter-individual variability of ciprofloxacin pharmacokinetics in ICU patients was observed. The poor target attainment supports the use of higher doses such as 1200 mg/day in critically ill patients, while the variability of inter-individual pharmacokinetics parameters emphasizes the need for therapeutic drug monitoring to ensure optimal exposure. Show less