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1.  Dissociation between sublingual and gut microcirculation in the response to a fluid challenge in postoperative patients with abdominal sepsis 
Background
This study was performed to compare intestinal and sublingual microcirculation and their response to a fluid challenge.
Methods
Twenty-two septic patients in the first postoperative day of an intestinal surgery, in which an ostomy had been constructed, were evaluated both before and 20 min after a challenge of 10 mL/kg of 6% hydroxyethylstarch 130/0.4. We measured systemic hemodynamics and sublingual and intestinal microcirculation. Correlations between variables were determined through the Pearson test.
Results
Fluid administration increased the cardiac index (2.6 ± 0.5 vs. 3.3 ± 1.0 L/min/m2, P < 0.01) and mean arterial blood pressure (68 ± 11 vs. 82 ± 12 mm Hg, P < 0.0001). The sublingual but not the intestinal red blood cell (RBC) velocity increased (912 ± 270 vs. 1,064 ± 200 μm/s, P < 0.002 and 679 ± 379 vs. 747 ± 419 μm/s, P = 0.12, respectively). The sublingual and intestinal perfused vascular density (PVD) did not change significantly (15.2 ± 2.9 vs. 16.1 ± 1.2 mm/mm2 and 12.3 ± 6.7 vs. 13.0 ± 6.7 mm/mm2). We found no correlation between the basal sublingual and intestinal RBC velocities or between their changes in response to the fluid challenge. The individual changes in sublingual RBC velocity correlated with those in cardiac index and basal RBC velocity. Individual changes in intestinal RBC velocity did not correlate with either the cardiac index modifications or the basal RBC velocity. The same pattern was observed with the sublingual and the intestinal PVDs. The sublingual RBC velocities and PVDs were similar between survivors and nonsurvivors. But the intestinal RBC velocities and PVDs were lower in nonsurvivors.
Conclusions
In this series of postoperative septic patients, we found a dissociation between sublingual and intestinal microcirculation. The improvement in the sublingual microcirculation after fluid challenge was dependent on the basal state and the increase in cardiac output. In contrast, the intestinal microcirculation behaved as an isolated territory.
doi:10.1186/s13613-014-0039-3
PMCID: PMC4298674  PMID: 25625013
Microcirculation; Tissue perfusion; Fluid challenge; Septic shock; Intestine; Sublingual; Abdominal surgery
2.  Choices in fluid type and volume during resuscitation: impact on patient outcomes 
We summarize the emerging new literature regarding the pathophysiological principles underlying the beneficial and deleterious effects of fluid administration during resuscitation, as well as current recommendations and recent clinical evidence regarding specific colloids and crystalloids. This systematic review allows us to conclude that there is no clear benefit associated with the use of colloids compared to crystalloids and no evidence to support the unique benefit of albumin as a resuscitation fluid. Hydroxyethyl starch use has been associated with increased acute kidney injury (AKI) and use of renal replacement therapy. Other synthetic colloids (dextran and gelatins) though not well studied do not appear superior to crystalloids. Normal saline (NS) use is associated with hyperchloremic metabolic acidosis and increased risk of AKI. This risk is decreased when balanced salt solutions are used. Balanced crystalloid solutions have shown no harmful effects, and there is evidence for benefit over NS. Finally, fluid resuscitation should be applied in a goal-directed manner and targeted to physiologic needs of individual patients. The evidence supports use of fluids in volume-responsive patients whose end-organ perfusion parameters have not been met.
doi:10.1186/s13613-014-0038-4
PMCID: PMC4298675  PMID: 25625012
Colloids; Crystalloids; Osmolality; Glycocalyx; Intravascular volume replacement; Systematic review
3.  Involvement of ICU families in decisions: fine-tuning the partnership 
Families of patients are not simple visitors to the ICU. They have just been separated from a loved one, often someone they live with, either abruptly or, in nearly half the cases, because a chronic condition has suddenly worsened. They must cope with a serious illness of a loved one, while having to adapt to the unfamiliar and intimidating ICU environment. In many cases, the outcome of the critical illness is uncertain, a situation that causes considerable distress to the relatives. As shown by our research group and others, families exhibit symptoms of anxiety (70%) and depression (35%) in the first few days after admission, as well as symptoms of stress (33%) and difficulty understanding the information delivered by the healthcare staff (50%). Furthermore, relatives of patients who die in the ICU are at risk for psychiatric syndromes such as generalized anxiety, panic attacks, depression, and posttraumatic stress syndrome. In this setting of psychological distress, families are asked to consider sharing in healthcare decisions about their loved one in the ICU. This article aims to foster the debate about the shared decision-making process. We have three objectives: to transcend the overly simplistic position that opposes paternalism and autonomy, to build a view founded only on an evaluation of actual practice and experience in the field, and to keep the focus squarely on the patient. Families want information and communication time from the staff. Nurses and physicians need to understand that families can share in decisions only if the entire ICU staff actively promotes family involvement and, of course, if the family wants to participate in all or part of the decision-making process.
doi:10.1186/s13613-014-0037-5
PMCID: PMC4273688  PMID: 25593753
Information; Communication; End of life; Bereavement; Randomized controlled trials
4.  Multiplex PCR performed of bronchoalveolar lavage fluid increases pathogen identification rate in critically ill patients with pneumonia: a pilot study 
Background
In critically ill patients with pneumonia, accurate microorganism identification allows appropriate antibiotic treatment. In patients undergoing bronchoalveolar lavage (BAL), direct examination of the fluid using Gram staining provides prompt information but pathogen identification accuracy is low. Culture of BAL fluid is actually the reference, but it is not available before 24 to 48 h. In addition, pathogen identification rate observed with direct examination and culture is decreased when antibiotic therapy has been given prior to sampling. We therefore assessed, in critically ill patients with suspected pneumonia, the performance of a multiplex PCR (MPCR) to identify pathogens in BAL fluid. This study is a prospective pilot observation.
Methods
We used a MPCR detecting 20 types of microorganisms. Direct examination, culture, and MPCR were performed on BAL fluid of critically ill patients with pneumonia suspicion. The final diagnosis of infective pneumonia was retained after the medical chart was reviewed by two experts. Pathogen identification rate of direct examination, culture, and MPCR in patients with confirmed pneumonia was compared.
Results
Among the 65 patients with pneumonia suspicion, the diagnosis of pneumonia was finally retained in 53 cases. Twenty nine (55%) were community-acquired pneumonia and 24 (45%) were hospital acquired. Pathogen identification rate with MPCR (66%) was greater than with culture (40%) and direct examination (23%) (p =0.01 and p <0.001, respectively). When considering only the microorganisms included in the MPCR panel, the pathogen identification rate provided by MPCR reached 82% and was still higher than with culture (35%, p <0.001) and direct examination (21%, p <0.001). Pathogen identification rate provided by MPCR was not modified in the case of previous antibiotic treatment (66% vs. 64%, NS) and was still better than with culture (23%, p <0.001).
Conclusions
The results of this pilot study suggest that in critically ill patients, MPCR performed on BAL fluid could provide higher identification rate of pathogens involved in pneumonia than direct examination and culture, especially in patients having received antimicrobial treatment.
doi:10.1186/s13613-014-0035-7
PMCID: PMC4273674  PMID: 25593751
Multiplex PCR; SeptiFast®; Bronchoalveolar lavage; Antibiotic therapy; Prior antibiotic treatment; Community-acquired pneumonia; Hospital-acquired pneumonia; Ventilator-acquired pneumonia
5.  Postpartum acute renal failure: a multicenter study of risk factors in patients admitted to ICU 
Background
Even in developed countries, severe specific pregnancy complications may occur in the immediate postpartum period and require admission to the ICU. The characteristics and risk factors of acute renal failure (ARF) induced by these complications and their treatments are not well known.
Methods
We performed a retrospective multicenter study in three intensive care departments linked to level III maternity wards in the north of France. All patients admitted to ICU for postpartum complications over a 5-year period (2008 to 2012) were included. Clinical and biological data, delivery characteristics, type of complications, and treatments were compared by univariate and multivariate analyses according to the occurrence and severity of ARF.
Results
One hundred eighty-two patients admitted to ICU for postpartum complications were included in the study. Sixty-eight patients (37%) developed an ARF: 49 with a low or medium severity and 19 with a severe ARF requiring renal replacement therapy. Hemolysis, elevated liver enzyme, and low platelet count (HELLP) syndrome on its own (p = 0.047) or combined with postpartum haemorrhage (p = 0.003), previous treatment by hyperoncotic albumin infusion (p = 0.001) and blockade of fibrinolysis by tranexamic acid (p = 0.03), was associated with secondary ARF. By multivariate analysis, the only independent factors were the association of HELLP syndrome with postpartum haemorrhage and the use of hyperoncotic albumin infusion.
Conclusions
HELLP syndrome associated with postpartum haemorrhage induces a high risk of ARF in the complicated postpartum setting. A particular attention should be given to treatments that could worsen the kidney function in that situation.
doi:10.1186/s13613-014-0036-6
PMCID: PMC4273687  PMID: 25593752
Pregnancy; Postpartum complications; Intensive care; Acute renal failure; HELLP syndrome; Postpartum haemorrhage; Hyperoncotic albumin; Tranexamic acid
6.  Healthcare-associated bloodstream infections in critically ill patients: descriptive cross-sectional database study evaluating concordance with clinical site isolates 
Background
Healthcare-associated bloodstream infections are related to both increased antibiotic use and risk of adverse outcomes. An in-depth understanding of their epidemiology is essential to reduce occurrence and to improve outcomes by targeted prevention strategies. The objectives of the study were to determine the epidemiology, source and concordance of healthcare-associated bloodstream infections with clinical site isolates.
Methods
We conducted a descriptive cross-sectional study in critically ill adults admitted to a tertiary semi-closed intensive care unit in England to determine the epidemiology, source and concordance of healthcare-associated bloodstream infections with clinical site isolates. All nosocomial positive blood cultures over a 4-year study period were identified. Pathogens detected and concordances with clinical site are reported as proportions.
Results
Contaminant pathogens accounted for half of the isolates. The most common non-contaminant pathogens cultured were Pseudomonas spp. (8.0%), Enterococcus spp. (7.3%) and Escherichia coli (5.6%). Central venous catheter-linked bloodstream infections represent only 6.0% of the positive blood cultures. Excluding contaminants and central venous line infections, in only 39.5% of the bloodstream infections could a concordant clinical site source be identified, the respiratory and urinary tracts being the most common.
Conclusions
Clinical practice should focus on a) improving blood culture techniques to reduce detection of contaminant pathogens and b) ensuring paired clinical site cultures are performed alongside all blood cultures to better understand the epidemiology and potential implications of primary and secondary discordant health-care associated bloodstream infections.
doi:10.1186/s13613-014-0034-8
PMCID: PMC4273689  PMID: 25593750
Bacteremia; Intensive care units; Nosocomial infections
7.  A ventilator strategy combining low tidal volume ventilation, recruitment maneuvers, and high positive end-expiratory pressure does not increase sedative, opioid, or neuromuscular blocker use in adults with acute respiratory distress syndrome and may improve patient comfort 
Background
The Lung Open Ventilation Study (LOV Study) compared a low tidal volume strategy with an experimental strategy combining low tidal volume, lung recruitment maneuvers, and higher plateau and positive end-expiratory pressures (PEEP) in adults with acute respiratory distress syndrome (ARDS). Herein, we compared sedative, opioid, and neuromuscular blocker (NMB) use among patients managed with the intervention and control strategies and clinicians' assessment of comfort in both groups.
Methods
This was an observational substudy of the LOV Study, a randomized trial conducted in 30 intensive care units in Canada, Australia, and Saudi Arabia. In 16 centers, we recorded daily doses of sedatives, opioids, and NMBs and surveyed bedside clinicians about their own comfort with the assigned ventilator strategy and their perceptions of patient comfort. We compared characteristics and outcomes of patients who did and did not receive NMBs.
Results
Study groups received similar sedative, opioid, and NMB dosing on days 1, 3, and 7. Patient comfort as assessed by clinicians was not different in the two groups: 93% perceived patients had no/minimal discomfort. In addition, 92% of clinicians were comfortable with the assigned ventilation strategy without significant differences between the two groups. When clinicians expressed discomfort, more expressed discomfort about PEEP levels in the intervention vs control group (2.9% vs 0.7%, P <0.0001), and more perceived patient discomfort among controls (6.0% vs 4.3%, P = 0.049). On multivariable analysis, the strongest associations with NMB use were higher plateau pressure (hazard ratio (HR) 1.15; 95% confidence interval (CI) 1.07 to 1.23; P = 0.0002) and higher daily sedative dose (HR 1.03; 95% CI 1.02 to 1.05; P <0.0001). Patients receiving NMBs had more barotrauma, longer durations of mechanical ventilation and hospital stay, and higher mortality.
Conclusions
In the LOV Study, high PEEP, low tidal volume ventilation did not increase sedative, opioid, or NMB doses in adults with ARDS, compared with a lower PEEP strategy, and appeared at least as comfortable for patients. NMB use may reflect worse lung injury, as these patients had more barotrauma, longer durations of ventilation, and higher mortality.
Trial registration
ClinicalTrials.gov Identifier NCT00182195
doi:10.1186/s13613-014-0033-9
PMCID: PMC4273695  PMID: 25593749
ARDS; Neuromuscular blocker; Sedation; Opioid; Mechanical ventilation; Clinician comfort
8.  Systemic corticosteroids in acute exacerbation of COPD: a meta-analysis of controlled studies with emphasis on ICU patients 
Guidelines on systemic corticosteroids in chronic obstructive pulmonary disease (COPD) exacerbation rely on studies that excluded patients requiring ventilatory support. Recent publication of studies including ICU patients allows estimation of the level of evidence overall and in patients admitted to the ICU. We included RCTs evaluating the efficacy and safety of systemic corticosteroids in COPD exacerbation, compared to placebo or standard treatment. The effect size on treatment success was computed by a random effects model overall and in subgroups of non-ICU and ICU patients. Effects on mortality and on the rate of adverse effects of corticosteroids were also computed. Twelve RCTs (including 1,331 patients) were included. Pooled analysis showed a statistically significant increase in the treatment success rate when using systemic corticosteroids: odds ratio (OR) = 1.72, 95% confidence interval (CI) = 1.15 to 2.57; p = 0.01. Subgroup analysis showed different patterns of effect in ICU and non-ICU subpopulations: a non-significant difference of effect in the subgroup of ICU patients (OR = 1.34, 95% CI = 0.61 to 2.95; p = 0.46), whereas in the non-ICU patients, the effect was significant (OR = 1.87, 95% CI = 1.18 to 2.99; p = 0.01; p for interaction = 0.72). Among ICU patients, there was no difference in the success whether patients were ventilated with tracheal intubation (OR = 1.85, 95% CI = 0.14 to 23.34; p = 0.63) or with non-invasive ventilation (OR = 4.88, 95% CI = 0.31 to 75.81; p = 0.25). Overall, there was no difference in the mortality rate between the steroid-treated group and controls: OR = 1.07, 95% CI = 0.67 to 1.71; p = 0.77. The rate of adverse events increased significantly with corticosteroid administration (OR = 2.36, 95% CI = 1.67 to 3.33; p < 0.0001). In particular, treatment with systemic corticosteroids significantly increased the risk of hyperglycemic episodes requiring initiation or alteration of insulin therapy (OR = 2.96, 95% CI = 1.69 to 5; p < 0.0001). We found corticosteroids to be beneficial in the whole population (non-critically ill and critically ill patients) in terms of treatment success rate. However, subgroup analysis showed that this effect of corticosteroids was only observed in non-critically ill patients whereas critically ill patients derived no benefit from systemic corticosteroids regardless of the chosen ventilatory mode (invasive or non-invasive ventilation). Further analyses showed no effect on mortality of corticosteroids, but higher side effects, such as hyperglycemic episodes requiring the initiation or alteration of insulin therapy.
doi:10.1186/s13613-014-0032-x
PMCID: PMC4273682  PMID: 25593748
COPD; Exacerbation; Corticosteroids; Critical care
9.  When to stop septic shock resuscitation: clues from a dynamic perfusion monitoring 
Background
The decision of when to stop septic shock resuscitation is a critical but yet a relatively unexplored aspect of care. This is especially relevant since the risks of over-resuscitation with fluid overload or inotropes have been highlighted in recent years. A recent guideline has proposed normalization of central venous oxygen saturation and/or lactate as therapeutic end-points, assuming that these variables are equivalent or interchangeable. However, since the physiological determinants of both are totally different, it is legitimate to challenge the rationale of this proposal. We designed this study to gain more insights into the most appropriate resuscitation goal from a dynamic point of view. Our objective was to compare the normalization rates of these and other potential perfusion-related targets in a cohort of septic shock survivors.
Methods
We designed a prospective, observational clinical study. One hundred and four septic shock patients with hyperlactatemia were included and followed until hospital discharge. The 84 hospital-survivors were kept for final analysis. A multimodal perfusion assessment was performed at baseline, 2, 6, and 24 h of ICU treatment.
Results
Some variables such as central venous oxygen saturation, central venous-arterial pCO2 gradient, and capillary refill time were already normal in more than 70% of survivors at 6 h. Lactate presented a much slower normalization rate decreasing significantly at 6 h compared to that of baseline (4.0 [3.0 to 4.9] vs. 2.7 [2.2 to 3.9] mmol/L; p < 0.01) but with only 52% of patients achieving normality at 24 h. Sublingual microcirculatory variables exhibited the slowest recovery rate with persistent derangements still present in almost 80% of patients at 24 h.
Conclusions
Perfusion-related variables exhibit very different normalization rates in septic shock survivors, most of them exhibiting a biphasic response with an initial rapid improvement, followed by a much slower trend thereafter. This fact should be taken into account to determine the most appropriate criteria to stop resuscitation opportunely and avoid the risk of over-resuscitation.
doi:10.1186/s13613-014-0030-z
PMCID: PMC4273696  PMID: 25593746
Septic shock; Perfusion; Resuscitation; Lactate; Microcirculation
10.  Timing of (supplemental) parenteral nutrition in critically ill patients: a systematic review 
Supplemental parenteral nutrition (SPN) is used in a step-up approach when full enteral support is contraindicated or fails to reach caloric targets. Recent nutrition guidelines present divergent advices regarding timing of SPN in critically ill patients ranging from early SPN (<48 h after admission; EPN) to postponing initiation of SPN until day 8 after Intensive Care Unit (ICU) admission (LPN). This systematic review summarizes results of prospective studies among adult ICU patients addressing the best timing of (supplemental) parenteral nutrition (S)PN. A structured PubMed search was conducted to identify eligible articles. Articles were screened and selected using predetermined criteria and appraised for relevance and validity. After critical appraisal, four randomized controlled trials (RCTs) and two prospective observational studies remained. One RCT found a higher percentage of alive discharge from the ICU at day 8 in the LPN group compared to EPN group (p = 0.007) but no differences in ICU and in-hospital mortality. None of the other RCTs found differences in ICU or in-hospital mortality rates. Contradicting or divergent results on other secondary outcomes were found for ICU length of stay, hospital length of stay, infection rates, nutrition targets, duration of mechanical ventilation, glucose control, duration of renal replacement therapy, muscle wasting and fat loss. Although the heterogeneity in quality and design of relevant studies precludes firm conclusions, it is reasonable to assume that in adult critically ill patients, there are no clinically relevant benefits of EPN compared with LPN with respect to morbidity or mortality end points, when full enteral support is contraindicated or fails to reach caloric targets. However, considering that infectious morbidity and resolution of organ failure may be negatively affected through mechanisms not yet clearly understood and acquisition costs of parenteral nutrition are higher, the early administration of parenteral nutrition cannot be recommended.
doi:10.1186/s13613-014-0031-y
PMCID: PMC4273685  PMID: 25593747
Critically ill patient; ICU; Parenteral nutrition; Supplemental parenteral nutrition; Timing; Mortality; Nutritional support; Mechanical ventilation; Renal replacement therapy; Muscle wasting
11.  High-flow nasal cannula: recommendations for daily practice in pediatrics 
High-flow nasal cannula (HFNC) is a relatively new device for respiratory support. In pediatrics, HFNC use continues to increase as the system is easily set up and is well tolerated by patients. The use of nasal cannula adapted to the infant’s nares size to deliver heated and humidified gas at high flow rates has been associated with improvements in washout of nasopharyngeal dead space, lung mucociliary clearance, and oxygen delivery compared with other oxygen delivery systems. HFNC may also create positive pharyngeal pressure to reduce the work of breathing, which positions the device midway between classical oxygen delivery systems, like the high-concentration face mask and continuous positive airway pressure (CPAP) generators. Currently, most of the studies in the pediatric literature suggest the benefits of HFNC therapy only for moderately severe acute viral bronchiolitis. But, the experience with this device in neonatology and adult intensive care may broaden the pediatric indications to include weaning from invasive ventilation and acute asthma. As for any form of respiratory support, HFNC initiation in patients requires close monitoring, whether it be for pre- or inter-hospital transport or in the emergency department or the pediatric intensive care unit.
doi:10.1186/s13613-014-0029-5
PMCID: PMC4273693  PMID: 25593745
PICU; High-flow nasal cannula; Bronchiolitis; Asthma
12.  Pulmonary vascular dysfunction in ARDS 
Acute respiratory distress syndrome (ARDS) is characterised by diffuse alveolar damage and is frequently complicated by pulmonary hypertension (PH). Multiple factors may contribute to the development of PH in this setting. In this review, we report the results of a systematic search of the available peer-reviewed literature for papers that measured indices of pulmonary haemodynamics in patients with ARDS and reported on mortality in the period 1977 to 2010. There were marked differences between studies, with some reporting strong associations between elevated pulmonary arterial pressure or elevated pulmonary vascular resistance and mortality, whereas others found no such association. In order to discuss the potential reasons for these discrepancies, we review the physiological concepts underlying the measurement of pulmonary haemodynamics and highlight key differences between the concepts of resistance in the pulmonary and systemic circulations. We consider the factors that influence pulmonary arterial pressure, both in normal lungs and in the presence of ARDS, including the important effects of mechanical ventilation. Pulmonary arterial pressure, pulmonary vascular resistance and transpulmonary gradient (TPG) depend not alone on the intrinsic properties of the pulmonary vascular bed but are also strongly influenced by cardiac output, airway pressures and lung volumes. The great variability in management strategies within and between studies means that no unified analysis of these papers was possible. Uniquely, Bull et al. (Am J Respir Crit Care Med 182:1123–1128, 2010) have recently reported that elevated pulmonary vascular resistance (PVR) and TPG were independently associated with increased mortality in ARDS, in a large trial with protocol-defined management strategies and using lung-protective ventilation. We then considered the existing literature to determine whether the relationship between PVR/TPG and outcome might be causal. Although we could identify potential mechanisms for such a link, the existing evidence does not allow firm conclusions to be drawn. Nonetheless, abnormally elevated PVR/TPG may provide a useful index of disease severity and progression. Further studies are required to understand the role and importance of pulmonary vascular dysfunction in ARDS in the era of lung-protective ventilation.
doi:10.1186/s13613-014-0028-6
PMCID: PMC4273697  PMID: 25593744
ARDS; Pulmonary haemodynamics; Pulmonary vascular resistance; Pulmonary vascular dysfunction; Acute cor pulmonale; Outcome
13.  Early-phase changes of extravascular lung water index as a prognostic indicator in acute respiratory distress syndrome patients 
Background
The features of early-phase acute respiratory distress syndrome (ARDS) are leakage of fluid into the extravascular space and impairment of its reabsorption, resulting in extravascular lung water (EVLW) accumulation. The current study aimed to identify how the initial EVLW values and their change were associated with mortality.
Methods
This was a post hoc analysis of the PiCCO Pulmonary Edema Study, a multicenter prospective cohort study that included 23 institutions. Single-indicator transpulmonary thermodilution-derived EVLW index (EVLWi) and conventional prognostic factors were prospectively collected over 48 h after enrollment. Associations between 28-day mortality and each variable including initial (on day 0), mean, maximum, and Δ (subtracting day 2 from day 0) EVLWi were evaluated.
Results
We evaluated 192 ARDS patients (median age, 69 years (quartile, 24 years); Sequential Organ Failure Assessment (SOFA) score on admission, 10 (5); all-cause 28-day mortality, 31%). Although no significant differences were found in initial, mean, or maximum EVLWi, Δ-EVLWi was significantly higher (i.e., more reduction in EVLWi) in survivors than in non-survivors (3.0 vs. −0.3 mL/kg, p = 0.006). Age, maximum, and Δ-SOFA scores and Δ-EVLW were the independent predictors for survival according to the Cox proportional hazard model. Patients with Δ-EVLWi > 2.8 had a significantly higher incidence of survival than those with Δ-EVLWi ≤ 2.8 (log-rank test, χ2 = 7.08, p = 0.008).
Conclusions
Decrease in EVLWi during the first 48 h of ARDS may be associated with 28-day survival. Serial EVLWi measurements may be useful for understanding the pathophysiologic conditions in ARDS patients. A large multination confirmative trial is required.
doi:10.1186/s13613-014-0027-7
PMCID: PMC4273855  PMID: 25593743
Acute lung injury; Hemodynamics; Pulmonary edema; Transpulmonary thermodilution; Vascular permeability
14.  Mechanisms and etiologies of thrombocytopenia in the intensive care unit: impact of extensive investigations 
Background
Thrombocytopenia is common in the intensive care unit. Potential mechanisms and etiologies behind this phenomenon are multiple and often entangled. We assessed the effect of a systematic approach, using routinely available tests, on the proportion of patients in whom the mechanism (primary objective) and etiology (secondary objective) of thrombocytopenia in a mixed intensive care unit (ICU) could be identified.
Methods
Before-and-after study of all patients with thrombocytopenia was used. ‘Before’ group had no intervention. New standard operating procedures for thrombocytopenia management were introduced. In the ‘After’ group, bone marrow aspiration; determination of fibrinogen dosage, prothrombin time, factor V, D-dimers; assay of fibrin monomers, ferritin, triglycerides, lactic acid dehydrogenase, aspartate transaminase, alanine aminotransferase, vitamin B12, folates, reticulocytes, haptoglobin, and bilirubin were performed.
Results
In the Before group (n = 20), the mechanism (central, peripheral, or mixed) was identified in 10 % versus 83% in After group (n = 23) (p < 0.001) (48% peripheral, 35% mixed). Before intervention, ≥1 etiology was identified in 15% versus 95.7% in the After group (p < 0.001).
Conclusions
Systematic and extensive investigation using routine tests highlights the mechanisms and etiology of thrombocytopenia in most cases.
doi:10.1186/s13613-014-0024-x
PMCID: PMC4273722  PMID: 25593741
Thrombocytopenia; Intensive care unit; Bone marrow aspiration
15.  Duration of hemodynamic effects of crystalloids in patients with circulatory shock after initial resuscitation 
Background
In the later stages of circulatory shock, monitoring should help to avoid fluid overload. In this setting, volume expansion is ideally indicated only for patients in whom the cardiac index (CI) is expected to increase. Crystalloids are usually the choice for fluid replacement. As previous studies evaluating the hemodynamic effect of crystalloids have not distinguished responders from non-responders, the present study was designed to evaluate the duration of the hemodynamic effects of crystalloids according to the fluid responsiveness status.
Methods
This is a prospective observational study conducted after the initial resuscitation phase of circulatory shock (>6 h vasopressor use). Critically ill, sedated adult patients monitored with a pulmonary artery catheter who received a fluid challenge with crystalloids (500 mL infused over 30 min) were included. Hemodynamic variables were measured at baseline (T0) and at 30 min (T1), 60 min (T2), and 90 min (T3) after a fluid bolus, totaling 90 min of observation. The patients were analyzed according to their fluid responsiveness status (responders with CI increase >15% and non-responders ≤15% at T1). The data were analyzed by repeated measures of analysis of variance.
Results
Twenty patients were included, 14 of whom had septic shock. Overall, volume expansion significantly increased the CI: 3.03 ± 0.64 L/min/m2 to 3.58 ± 0.66 L/min/m2 (p < 0.05). From this period, there was a progressive decrease: 3.23 ± 0.65 L/min/m2 (p < 0.05, T2 versus T1) and 3.12 ± 0.64 L/min/m2 (p < 0.05, period T3 versus T1). Similar behavior was observed in responders (13 patients), 2.84 ± 0.61 L/min/m2 to 3.57 ± 0.65 L/min/m2 (p < 0.05) with volume expansion, followed by a decrease, 3.19 ± 0.69 L/min/m2 (p < 0.05, T2 versus T1) and 3.06 ± 0.70 L/min/m2 (p < 0.05, T3 versus T1). Blood pressure and cardiac filling pressures also decreased significantly after T1 with similar findings in both responders and non-responders.
Conclusions
The results suggest that volume expansion with crystalloids in patients with circulatory shock after the initial resuscitation has limited success, even in responders.
doi:10.1186/s13613-014-0025-9
PMCID: PMC4273721  PMID: 25593742
Fluid; Fluid responsiveness; Fluid resuscitation; Crystalloids; Circulatory shock; Hemodynamics
16.  The methodological quality of animal research in critical care: the public face of science 
Background
Animal research (AR) findings often do not translate to humans; one potential reason is the poor methodological quality of AR. We aimed to determine this quality of AR reported in critical care journals.
Methods
All AR published from January to June 2012 in three high-impact critical care journals were reviewed. A case report form and instruction manual with clear definitions were created, based on published recommendations, including the ARRIVE guidelines. Data were analyzed with descriptive statistics.
Results
Seventy-seven AR publications were reviewed. Our primary outcome (animal strain, sex, and weight or age described) was reported in 52 (68%; 95% confidence interval, 56% to 77%). Of the 77 publications, 47 (61%) reported randomization; of these, 3 (6%) reported allocation concealment, and 1 (2%) the randomization procedure. Of the 77 publications, 31 (40%) reported some type of blinding; of these, disease induction (2, 7%), intervention (7, 23%), and/or subjective outcomes (17, 55%) were blinded. A sample size calculation was reported in 4/77 (5%). Animal numbers were missing in the Methods section in 16 (21%) publications; when stated, the median was 32 (range 6 to 320; interquartile range, 21 to 70). Extra animals used were mentioned in the Results section in 31 (40%) publications; this number was unclear in 23 (74%), and >100 for 12 (16%). When reporting most outcomes, numbers with denominators were given in 35 (45%), with no unaccounted numbers in 24 (31%), and no animals excluded from analysis in 20 (26%). Most (49, 64%) studies reported >40, and another 19 (25%) reported 21 to 40 statistical comparisons. Internal validity limitations were discussed in 7 (9%), and external validity (to humans) discussed in 71 (92%), most with no (30, 42%) or only a vague (9, 13%) limitation to this external validity mentioned.
Conclusions
The reported methodological quality of AR was poor. Unless the quality of AR significantly improves, the practice may be in serious jeopardy of losing public support.
doi:10.1186/s13613-014-0026-8
PMCID: PMC4126494  PMID: 25114829
Animal research; Critical care; Intensive care; Methodology
17.  Self-reported attitudes versus actual practice of oxygen therapy by ICU physicians and nurses 
Background
High inspiratory oxygen concentrations are frequently administered in ventilated patients in the intensive care unit (ICU) but may induce lung injury and systemic toxicity. We compared beliefs and actual clinical practice regarding oxygen therapy in critically ill patients.
Methods
In three large teaching hospitals in the Netherlands, ICU physicians and nurses were invited to complete a questionnaire about oxygen therapy. Furthermore, arterial blood gas (ABG) analysis data and ventilator settings were retrieved to assess actual oxygen practice in the same hospitals 1 year prior to the survey.
Results
In total, 59% of the 215 respondents believed that oxygen-induced lung injury is a concern. The majority of physicians and nurses stated that minimal acceptable oxygen saturation and partial arterial oxygen pressure (PaO2) ranges were 85% to 95% and 7 to 10 kPa (52.5 to 75 mmHg), respectively. Analysis of 107,888 ABG results with concurrent ventilator settings, derived from 5,565 patient admissions, showed a median (interquartile range (IQR)) PaO2 of 11.7 kPa (9.9 to 14.3) [87.8 mmHg], median fractions of inspired oxygen (FiO2) of 0.4 (0.4 to 0.5), and median positive end-expiratory pressure (PEEP) of 5 (5 to 8) cm H2O. Of all PaO2 values, 73% were higher than the upper limit of the commonly self-reported acceptable range, and in 58% of these cases, neither FiO2 nor PEEP levels were lowered until the next ABG sample was taken.
Conclusions
Most ICU clinicians acknowledge the potential adverse effects of prolonged exposure to hyperoxia and report a low tolerance for high oxygen levels. However, in actual clinical practice, a large proportion of their ICU patients was exposed to higher arterial oxygen levels than self-reported target ranges.
doi:10.1186/s13613-014-0023-y
PMCID: PMC4240734  PMID: 25512878
Oxygen; Hyperoxia; Mechanical ventilation; Lung injury; Intensive care medicine; Questionnaire
18.  Ethical reflections on end-of-life signs and symptoms in the intensive care setting: a place for neuromuscular blockers? 
The death of a loved one is often an ordeal and a tragedy for those who witness it, as death is not merely the end of a life, but also the end of an existence, the loss of a unique individual who is special and irreplaceable. In some situations, end-of-life signs, such as agonal gasps, can be an almost unbearable “sight” because the physical manifestations are hard to watch and can lead to subjective interpretation and irrational fears. Ethical unease arises as the dying patient falls prey to death throes and to the manifestations of ebbing life and the physician can only stand by and watch. From this point on, medicine can put an end to suffering by the use of neuromuscular blockade, but in so doing life ceases at the same time. It is difficult, however, not to respond to the distress of loved ones and caregivers. The ethical problem then becomes the shift from the original ethical concern, i.e. the dying patient, to the patient’s loved ones. Is such a rupture due to a difference in nature or a difference in degree, given that the dying patient remains a person and not a thing as long as the body continues to lead its own life, expressed through movement and sound? Because there cannot be any simple and unequivocal answer to this question, the SRLF Ethics Commission is offering ethical reflections on end-of-life signs and symptoms in the intensive care setting, and on the use of neuromuscular blockade in this context, with presentations on the subject by two philosophers and members of the SRLF Ethics Commission, Ms Lise Haddad and Prof Dominique Folscheid. The SRLF Ethics Commission hopes to provide food for thought for everyone on this topic, which undoubtedly calls for further contributions, the aim being not to provide ready-made solutions or policy, but rather to allow everyone to ponder this question in all conscience.
doi:10.1186/2110-5820-4-23
PMCID: PMC4098689  PMID: 25045580
Ethics; End of life; Critical care; Gasps
19.  ICG-liver test versus new biomarkers as prognostic markers for prolonged length of stay in critically ill patients - a prospective study of accuracy for prediction of length of stay in the ICU 
Background
Prognostic abilities of medical parameters, which are scoring systems, measurements and biomarkers, are important for stratifying critically ill patients. Indocyanine green plasma disappearance (ICG-PDR) is an established clinical tool for the assessment of liver perfusion and function. Copeptin, MR-proANP and pro-ADM are biomarkers whose prognostic value is still unclear. The goal of this prospective study was to evaluate ICG-PDR, copeptin, MR-proANP and pro-ADM to predict prolonged length of stay (pLOS) in the ICU.
Methods
This study was conducted as a prospective single center study including 110 consecutively admitted ICU patients. Primary endpoint was prolonged length of stay (pLOS) in the ICU, defined as more than three days of stay there.
Results
ROC analysis showed an AUC of 0.73 for ICG-PDR, 0.70 for SAPS II, 0.65 for MR-proANP, 0.64 for pro-ADM and 0.54 for copeptin for pLOS in the ICU.
Conclusions
The prediction of pLOS in the ICU might be better by means of ICG-PDR than with the new biomarkers copeptin, MR-proANP or pro-ADM. Nevertheless, there is more need for research to evaluate whether ICG-PDR is an overall prognostic marker for pLOS.
Trial registration
(ClinicalTrials.gov number, NCT01126554).
doi:10.1186/s13613-014-0019-7
PMCID: PMC4100565  PMID: 25045579
Copeptin; MR-proANP; pro-ADM; ICG-Liver test; ICG-PDR; pLOS; Length of stay in the ICU
20.  Design and implementation of the START (STem cells for ARDS Treatment) trial, a phase 1/2 trial of human mesenchymal stem/stromal cells for the treatment of moderate-severe acute respiratory distress syndrome 
Background
Despite advances in supportive care, moderate-severe acute respiratory distress syndrome (ARDS) is associated with high mortality rates, and novel therapies to treat this condition are needed. Compelling pre-clinical data from mouse, rat, sheep and ex vivo perfused human lung models support the use of human mesenchymal stem (stromal) cells (MSCs) as a novel intravenous therapy for the early treatment of ARDS.
Methods
This article describes the study design and challenges encountered during the implementation and phase 1 component of the START (STem cells for ARDS Treatment) trial, a phase 1/2 trial of bone marrow-derived human MSCs for moderate-severe ARDS. A trial enrolling 69 subjects is planned (9 subjects in phase 1, 60 subjects in phase 2 treated with MSCs or placebo in a 2:1 ratio).
Results
This report describes study design features that are unique to a phase 1 trial in critically ill subjects and the specific challenges of implementation of a cell-based therapy trial in the ICU.
Conclusions
Experience gained during the design and implementation of the START study will be useful to investigators planning future phase 1 clinical trials based in the ICU, as well as trials of cell-based therapy for other acute illnesses.
Trial registration
Clinical Trials Registration: NCT01775774 and NCT02097641.
doi:10.1186/s13613-014-0022-z
PMCID: PMC4273700  PMID: 25593740
Acute lung injury; Clinical trial; Mesenchymal stem/stromal cell; Pulmonary edema
21.  An increase in mean platelet volume after admission is associated with higher mortality in critically ill patients 
Background
Platelet activation and consumption are common in critically ill patients and are associated with poorer prognosis. Mean platelet volume is a simple surrogate for platelet activation, with higher MPV being associated with worse clinical condition on a large array of clinical diagnoses. We therefore aimed to investigate associations between changes in platelet count and mean platelet volume (MPV) with prognosis and inflammatory cytokine values in critically ill patients.
Methods
This study prospectively included 84 critically ill patients. Patients were stratified into four groups according to proportional changes in MPV (ΔMPV24h) and platelet count (ΔPlat24h) in the first 24 hours after admission. Mortality between groups was compared using the χ2 test. Logistic regression was performed using hospital mortality as outcome and Simplified Acute Physiology Score (SAPS 3), ΔPlat24h and ΔMPV24h as covariates. Concentrations of the following inflammatory mediators were measured using Miliplex® technology: IL1β, IL6, IL8, IL10, epidermal growth factor, vascular endothelial growth factor, TNFα and IFNα. Cytokine concentrations were compared between groups using the Kruskal-Wallis test with Bonferroni correction.
Results
Patients in whom MPV increased and platelet count decreased had higher mortality rates (46%). According to logistic regression, ΔMPV24h was independently associated with increased mortality (OR 1.28 per 1% increase; 95% CI 1.08 to 1.48). No strong associations between inflammatory mediators and changes in MPV and platelet count were found.
Conclusion
An increase in MPV after admission to an ICU is independently associated with higher hospital mortality.
doi:10.1186/s13613-014-0020-1
PMCID: PMC4265891  PMID: 25520853
Platelet; Critical illness; Inflammation; Endothelial activation
22.  Iatrogenic salt water drowning and the hazards of a high central venous pressure 
Current teaching and guidelines suggest that aggressive fluid resuscitation is the best initial approach to the patient with hemodynamic instability. The source of this wisdom is difficult to discern, however, Early Goal Directed therapy (EGDT) as championed by Rivers et al. and the Surviving Sepsis Campaign Guidelines appears to have established this as the irrefutable truth. However, over the last decade it has become clear that aggressive fluid resuscitation leading to fluid overload is associated with increased morbidity and mortality across a diverse group of patients, including patients with severe sepsis as well as elective surgical and trauma patients and those with pancreatitis. Excessive fluid administration results in increased interstitial fluid in vital organs leading to impaired renal, hepatic and cardiac function. Increased extra-vascular lung water (EVLW) is particularly lethal, leading to iatrogenic salt water drowning. EGDT and the Surviving Sepsis Campaign Guidelines recommend targeting a central venous pressure (CVP) > 8 mmHg. A CVP > 8 mmHg has been demonstrated to decrease microcirculatory flow, as well as renal blood flow and is associated with an increased risk of renal failure and death. Normal saline (0.9% salt solution) as compared to balanced electrolyte solutions is associated with a greater risk of acute kidney injury and death. This paper reviews the adverse effects of large volume resuscitation, a high CVP and the excessive use of normal saline.
doi:10.1186/s13613-014-0021-0
PMCID: PMC4122823  PMID: 25110606
Fluid; Fluid balance; Normal saline; Lung water; Extra-vascular lung water; Central venous pressure; ICU; Lactate Ringers Solution; Acute respiratory distress syndrome; Sepsis; Mean circulatory filling pressure; Fluid overload
23.  Anemia and red blood cell transfusion in critically ill cardiac patients 
Anemia and red blood cell (RBC) transfusion occur frequently in hospitalized patients with cardiac disease. In this narrative review, we report the epidemiology of anemia and RBC transfusion in hospitalized adults and children (excluding premature neonates) with cardiac disease, and on the outcome of anemic and transfused cardiac patients. Both anemia and RBC transfusion are common in cardiac patients, and both are associated with mortality. RBC transfusion is the only way to rapidly treat severe anemia, but is not completely safe. In addition to hemoglobin (Hb) concentration, the determinant(s) that should drive a practitioner to prescribe a RBC transfusion to cardiac patients are currently unclear. In stable acyanotic cardiac patients, Hb level above 70 g/L in children and above 70 to 80 g/L in adults appears safe. In cyanotic children, Hb level above 90 g/L appears safe. The appropriate threshold Hb level for unstable cardiac patients and for children younger than 28 days is unknown. The optimal transfusion strategy in cardiac patients is not well characterized. The threshold at which the risk of anemia outweighs the risk of transfusion is not known. More studies are needed to determine when RBC transfusion is indicated in hospitalized patients with cardiac disease.
doi:10.1186/2110-5820-4-16
PMCID: PMC4085735  PMID: 25024880
Blood; Cardiac; Critical care; Erythrocyte; Hemoglobin; Intensive care; Practice; Risk factors; Surgery; Transfusion
24.  Extracorporeal life support for patients with acute respiratory distress syndrome: report of a Consensus Conference 
The influenza H1N1 epidemics in 2009 led a substantial number of people to develop severe acute respiratory distress syndrome and refractory hypoxemia. In these patients, extracorporeal membrane oxygenation was used as rescue oxygenation therapy. Several randomized clinical trials and observational studies suggested that extracorporeal membrane oxygenation associated with protective mechanical ventilation could improve outcome, but its efficacy remains uncertain. Organized by the Société de Réanimation de Langue Française (SRLF) in conjunction with the Société Française d’Anesthésie et de Réanimation (SFAR), the Société de Pneumologie de Langue Française (SPLF), the Groupe Francophone de Réanimation et d’Urgences Pédiatriques (GFRUP), the Société Française de Perfusion (SOFRAPERF), the Société Française de Chirurgie Thoracique et Cardiovasculaire (SFCTV) et the Sociedad Española de Medecina Intensiva Critica y Unidades Coronarias (SEMICYUC), a Consensus Conference was held in December 2013 and a jury of 13 members wrote 65 recommendations to answer the five following questions regarding the place of extracorporeal life support for patients with acute respiratory distress syndrome: 1) What are the available techniques?; 2) Which patients could benefit from extracorporeal life support?; 3) How to perform extracorporeal life support?; 4) How and when to stop extracorporeal life support?; 5) Which organization should be recommended? To write the recommendations, evidence-based medicine (GRADE method), expert panel opinions, and shared decisions taken by all the thirteen members of the jury of the Consensus Conference were taken into account.
doi:10.1186/2110-5820-4-15
PMCID: PMC4046033  PMID: 24936342
Extracorporeal life support; Extracorporeal membrane oxygenation; Extracorporeal CO2 removal; Acute respiratory distress syndrome; Protective ventilation
25.  Daily sedative interruption versus intermittent sedation in mechanically ventilated critically ill patients: a randomized trial 
Background
Daily sedative interruption and intermittent sedation are effective in abbreviating the time on mechanical ventilation. Whether one is superior to the other has not yet been determined. Our aim was to compare daily interruption and intermittent sedation during the mechanical ventilation period in a low nurse staffing ICU.
Methods
Adult patients expected to need mechanical ventilation for more than 24 hours were randomly assigned, in a single center, either to daily interruption of continuous sedative and opioid infusion or to intermittent sedation. In both cases, our goal was to maintain a Sedation Agitation Scale (SAS) level of 3 or 4; that is patients should be calm, easily arousable or awakened with verbal stimuli or gentle shaking. Primary outcome was ventilator-free days in 28 days. Secondary outcomes were ICU and hospital mortality, incidence of delirium, nurse workload, self-extubation and psychological distress six months after ICU discharge.
Results
A total of 60 patients were included. There were no differences in the ventilator-free days in 28 days between daily interruption and intermittent sedation (median: 24 versus 25 days, P = 0.160). There were also no differences in ICU mortality (40 versus 23.3%, P = 0.165), hospital mortality (43.3 versus 30%, P = 0.284), incidence of delirium (30 versus 40%, P = 0.472), self-extubation (3.3 versus 6.7%, P = 0.514), and psychological stress six months after ICU discharge. Also, the nurse workload was not different between groups, but it was reduced on day 5 compared to day 1 in both groups (Nurse Activity Score (NAS) in the intermittent sedation group was 54 on day 1 versus 39 on day 5, P < 0.001; NAS in daily interruption group was 53 on day 1 versus 38 on day 5, P < 0.001). Fentanyl and midazolam total dosages per patient were higher in the daily interruption group. The tidal volume was higher in the intermittent sedation group during the first five days of ICU stay.
Conclusions
There was no difference in the number of ventilator-free days in 28 days between both groups. Intermittent sedation was associated with lower sedative and opioid doses.
Trial registration
ClinicalTrials.gov Identifier: NCT00824239.
doi:10.1186/2110-5820-4-14
PMCID: PMC4026117  PMID: 24900938
Sedation; Mechanical ventilation; Conscious sedation; Critical care and outcome assessment

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