Accuracy and feasibility of point-of-care and continuous blood glucose analysis in critically ill ICU patients

INTRODUCTION: To obtain strict glucose regulation, an accurate and feasible bedside glucometry method is essential. We evaluated three different types of point-of-care glucometry in seriously ill intensive care unit (ICU) patients. The study was performed as a single-centre, prospective, observational study in a 12-bed medical ICU of a university hospital. METHODS: Patients with an expected ICU stay of more than 48 hours were included. Because the reference laboratory delivers glucose values after approximately 30 to 60 minutes, which is too slow to use in a glucose regulation protocol and for calibration of the subcutaneous continuous glucose monitoring system (CGMS) (CGMS System Gold), we first validated the ICU-based blood gas/glucose analyser ABL715 (part 1 of the study). Subsequently, part 2 was performed: after inserting (and calibrating) the subcutaneous CGMS, heparinised arterial blood samples were drawn from an arterial line every 6 hours and analysed on both the Precision PCx point-of-care meter using test strips and on the blood gas/glucose analyser ABL715. CGMS glucose data were downloaded after 24 to 72 hours. The results of the paired measurements were analysed as a scatter plot by the method of Bland and Altman and were expressed as a correlation coefficient. RESULTS: Part 1: Four hundred and twenty-four blood samples were drawn from 45 critically ill ICU patients. The ICU-based blood gas/glucose analyser ABL715 provided a good estimate of conventional laboratory glucose assessment: the correlation coefficient was 0.95. In the Clarke error grid, 96.8% of the paired measurements were in the clinically acceptable zones A and B. Part 2: One hundred sixty-five paired samples were drawn from 19 ICU patients. The Precision PCx point-of-care meter showed a correlation coefficient of 0.89. Ninety-eight point seven percent of measurements were within zones A and B. The correlation coefficient for the subcutaneous CGMS System Gold was 0.89. One hundred percent of measurements were within zones A and B. CONCLUSION: The ICU-based blood glucose analyser ABL715 is a rapid and accurate alternative for laboratory glucose determination and can serve as a standard for ICU blood glucose measurements. The Precision PCx is a good alternative, but feasibility may be limited because of the blood sample handling. The subcutaneous CGMS System Gold is promising, but real-time glucose level reporting is necessary before it can be of clinical use in the ICU. When implementing a glucose-insulin algorithm in patient care or research, one should realise that the absolute glucose level may differ systematically among various measuring methods, influencing targeted glucose levels

Impact of digestive and oropharyngeal decontamination on the intestinal microbiota in ICU patients

Selective digestive microbial decontamination (SDD) is hypothesized to benefit patients in intensive care (ICU) by suppressing Gram-negative potential pathogens from the colon without affecting the anaerobic intestinal microbiota. The purpose of this study was to provide more insight to the effects of digestive tract and oropharyngeal decontamination on the intestinal microbiota by means of a prospective clinical trial in which faecal samples were collected from ICU patients for intestinal microbiota analysis. The faecal samples were collected from ICU patients enrolled in a multicentre trial to study the outcome of SDD and selective oral decontamination (SOD) in comparison with standard care (SC). Fluorescent in situ hybridization (FISH) was used to analyze the faecal microbiota. The numbers of bacteria from different bacterial groups were compared between the three regimens. The total counts of bacteria per gram faeces did not differ between regimens. The F. prausnitzii group of bacteria, representing an important group among intestinal microbiota, was significantly reduced in the SDD regimen compared to the SC and SOD. The Enterobacteriaceae were significantly suppressed during SDD compared to both SOD and SC; enterococci increased in SDD compared to both other regimens. The composition of the intestinal microbiota is importantly affected by SDD. The F. prausnitzii group was significantly suppressed during SDD. This group of microbiota is a predominant producer of butyrate, the main energy source for colonocytes. Reduction of this microbiota is an important trade-off while reducing gram-negative bacteria by SDD

Oxygen reserve index : validation of a new variable

BACKGROUND: Pulse oximetry-derived oxygen saturation is typically >97% in normoxia and hyperoxia, limiting its clinical use. The new Oxygen Reserve Index (ORi), a relative indicator of the partial pressure of oxygen dissolved in arterial blood (Pao(2)) in the range of 100-200 mm Hg, may allow additional monitoring of oxygen status. METHODS: In this prospective validation intervention study, 20 healthy volunteers were breathing standardized oxygen concentrations ranging from mild hypoxia (fraction of inspired oxygen = 0.14) to hyperoxia (fraction of inspired oxygen = 1.0) via a tight-fitting face mask. ORi was measured noninvasively by multiwavelength pulse co-oximetry using 2 finger sensors. These ORi values (unitless scale, 0.00-1.00) were compared with measured Pao(2) values. Repeated-measurements correlation analysis was performed to assess the ORi/Pao(2) relationship. ORi trending ability was assessed using a 4-quadrant plot. The area under the receiver operating characteristics curve was calculated to assess the prediction of hypoxia (low-ranged Pao(2), <100 mm Hg). RESULTS: Within the ORi-sensitive range, a strong positive correlation was found between ORi and Pao(2) for both sensors (R = 0.78 and 0.83; P < .0001). ORi trending of Pao(2) was good within this range (concordance rate = 94%). The prediction of Pao(2) <100 mm Hg was also good, with an area under the receiver operating characteristics curve of 0.91 and 99% sensitivity and 82% specificity. CONCLUSIONS: In this prospective volunteer validation study, a strong and positive correlation between Pao(2) and ORi was found, together with a good trending ability. Based on these data, the future use of ORi as a continuous noninvasive monitoring tool for assessing oxygenation status in patients receiving supplemental oxygen might be supported

Serial CSF sampling over a period of 30 h via an indwelling spinal catheter in healthy volunteers:headache, back pain, tolerability and measured acetylcholine profile

<p>Timed interval cerebrospinal fluid (CSF) sampling by indwelling catheterization can be a valuable corroborative tool for the pharmacokinetic and pharmacodynamic assessment of drugs. CSF sampling in studies on drug candidates for Alzheimer's disease have been conducted in evaluations of the biomarkers acetylcholine (ACh), tau proteins, amyloid precursor protein and beta-amyloid fragments. The primary aim of this study was to study the feasibility and the burden on the healthy volunteers of serial CSF sampling within the contract research organization environment in order to establish a standardized research tool for future drug development studies.</p><p>This study is a validation study in healthy subjects: eight healthy male subjects aged 55-75 years were enrolled. After eligibility had been confirmed, the subjects were admitted to the clinical pharmacology unit 2 days before starting the CSF sampling procedure. Hydration by drip infusion of 2 L saline was performed for 24 h before starting the CSF sampling procedure, and for antithrombotic purposes, Fraxiparine (nadroparine calcium) was given 12 and 36 h after intradural catheterization. CSF catheterization was performed by board-certified anesthesiologists with experience in inserting indwelling intrathecal catheters. Subjects only required to remain in a horizontal position for the first 24 h after removal of the catheter. CSF and blood samples were collected by interval sampling over a 30-h period.</p><p>The study was completed by seven of the eight subjects. Six subjects who completed the study reported adverse effects (AEs) which were all mild and from which they recovered during their stay in the clinic. A total of 25 AEs were reported of which 13 were considered to be procedure-related. The procedure was well tolerated by all participating subjects, and the VAS scale scores for headache and back pain were low. CSF samples were analyzed for ACh. All values were above the lowest limit of quantification. On average, the ACh concentration started at a low level but rose between 1 and 2 h after insertion of the catheter and then remained high during the whole sampling period up to 30 h.</p><p>Serial sampling of CSF in seven healthy volunteers up to 30 h occurred without serious complications and was well tolerated. The CSF collected was of good quality and facilitated the assessment of an Alzheimer's disease-sensitive biomarker. We conclude that this validation study can form the basis for future patient studies aimed at elucidating disease mechanisms and the pharmacodynamics of drugs in the developmental stage.</p>

Cardiac troponin I release and cytokine response during experimental human endotoxaemia

OBJECTIVE: To study the relationship between cytokine levels and cardiac troponin I (cTnI). DESIGN: Prospective experimental study. SETTING: Intensive care unit of a university hospital. PARTICIPANTS: Six healthy male volunteers. INTERVENTIONS. Endotoxin, 4 ng/kg, was given as a 1-min intravenous infusion. MEASUREMENTS AND RESULTS: Circulating cardiac troponin I levels and proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8) were analysed at various time points during a 24-h period. TNF-alpha appeared in the circulation 30 min after injection (T=0.5 h), reaching peak levels (5,665+/-1,910 pg/ml) 2 h after infusion. At T=24 h TNF-alpha was still elevated in the circulation compared to T=0. None of the six volunteers had a cTnI value higher than 0.1 microg/l at T=0, 6 h or 24 h. CONCLUSION: The presence of significant amounts of TNF-alpha, IL-6 and IL-8 in the systemic circulation does not lead to increased levels of cTnI in experimental human endotoxaemia

Incidence of severe critical events in paediatric anaesthesia (APRICOT) : a prospective multicentre observational study in 261 hospitals in Europe

BACKGROUND: Little is known about the incidence of severe critical events in children undergoing general anaesthesia in Europe. We aimed to identify the incidence, nature, and outcome of severe critical events in children undergoing anaesthesia, and the associated potential risk factors. METHODS: The APRICOT study was a prospective observational multicentre cohort study of children from birth to 15 years of age undergoing elective or urgent anaesthesia for diagnostic or surgical procedures. Children were eligible for inclusion during a 2-week period determined prospectively by each centre. There were 261 participating centres across 33 European countries. The primary endpoint was the occurence of perioperative severe critical events requiring immediate intervention. A severe critical event was defined as the occurrence of respiratory, cardiac, allergic, or neurological complications requiring immediate intervention and that led (or could have led) to major disability or death. This study is registered with ClinicalTrials.gov, number NCT01878760. FINDINGS: Between April 1, 2014, and Jan 31, 2015, 31 127 anaesthetic procedures in 30 874 children with a mean age of 6·35 years (SD 4·50) were included. The incidence of perioperative severe critical events was 5·2% (95% CI 5·0-5·5) with an incidence of respiratory critical events of 3·1% (2·9-3·3). Cardiovascular instability occurred in 1·9% (1·7-2·1), with an immediate poor outcome in 5·4% (3·7-7·5) of these cases. The all-cause 30-day in-hospital mortality rate was 10 in 10 000. This was independent of type of anaesthesia. Age (relative risk 0·88, 95% CI 0·86-0·90; p<0·0001), medical history, and physical condition (1·60, 1·40-1·82; p<0·0001) were the major risk factors for a serious critical event. Multivariate analysis revealed evidence for the beneficial effect of years of experience of the most senior anaesthesia team member (0·99, 0·981-0·997; p<0·0048 for respiratory critical events, and 0·98, 0·97-0·99; p=0·0039 for cardiovascular critical events), rather than the type of health institution or providers. INTERPRETATION: This study highlights a relatively high rate of severe critical events during the anaesthesia management of children for surgical or diagnostic procedures in Europe, and a large variability in the practice of paediatric anaesthesia. These findings are substantial enough to warrant attention from national, regional, and specialist societies to target education of anaesthesiologists and their teams and implement strategies for quality improvement in paediatric anaesthesia. FUNDING: European Society of Anaesthesiology