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Purpose: Intensive care is a stressful environment in which team-family conflicts commonly occur. If managed poorly, conflicts can have negative effects on all parties involved. Previous studies mainly investigated these conflicts and their management in a retrospective way. This study aimed to prospectively explore team-family conflicts, including its main topics, complicating factors, doctors’ conflict management strategies and the effect of these strategies. Methods: Conversations between doctors in the neonatal, pediatric, and adult intensive care unit of a large university-based hospital and families of critically ill patients were audio-recorded from the moment doubts arose whether treatment was still in patients’ best interest. Transcripts were coded and analyzed using a qualitative deductive approach. Results: Team-family conflicts occurred in 29 out of 101 conversations (29%) concerning 20 out of 36 patients (56%). Conflicts mostly concerned more than one topic. We identified four complicating context- and/or family-related factors: diagnostic and prognostic uncertainty, families’ strong negative emotions, limited health literacy, and burden of responsibility. Doctors used four overarching strategies to manage conflicts, namely content-oriented, process-oriented, moral and empathic strategies. Doctors mostly used content-oriented strategies, independent of the intensive care setting. They were able to effectively address conflicts in most conversations. Yet, if they did not acknowledge families’ cues indicating the existence of one or more complicating factors, conflicts were likely to linger on during the conversation. Conclusion: This study underlines the importance of doctors tailoring their communication strategies to the concrete conflict topic(s) and to the context- and family-related factors which complicate a specific conflict.

IntroductionHypotension is common during cardiac surgery and often persists postoperatively in the intensive care unit (ICU). Still, treatment is mainly reactive, causing a delay in its management. The Hypotension Prediction Index (HPI) can predict hypotension with high accuracy. Using the HPI combined with a guidance protocol resulted in a significant reduction in the severity of hypotension in four non-cardiac surgery trials. This randomised trial aims to evaluate the effectiveness of the HPI in combination with a diagnostic guidance protocol on reducing the occurrence and severity of hypotension during coronary artery bypass grafting (CABG) surgery and subsequent ICU admission.Methods and analysisThis is a single-centre, randomised clinical trial in adult patients undergoing elective on-pump CABG surgery with a target mean arterial pressure of 65 mm Hg. One hundred and thirty patients will be randomly allocated in a 1:1 ratio to either the intervention or control group. In both groups, a HemoSphere patient monitor with embedded HPI software will be connected to the arterial line. In the intervention group, HPI values of 75 or above will initiate the diagnostic guidance protocol, both intraoperatively and postoperatively in the ICU during mechanical ventilation. In the control group, the HemoSphere patient monitor will be covered and silenced. The primary outcome is the time-weighted average of hypotension during the combined study phases.Ethics and disseminationThe medical research ethics committee and the institutional review board of the Amsterdam UMC, location AMC, the Netherlands, approved the trial protocol (NL76236.018.21). No publication restrictions apply, and the study results will be disseminated through a peer-reviewed journal.Trial registration numberThe Netherlands Trial Register (NL9449), ClinicalTrials.gov (NCT05821647).

Purpose: In intensive care units (ICUs), decisions about the continuation or discontinuation of life-sustaining treatment (LST) are made on a daily basis. Professional guidelines recommend an open exchange of standpoints and underlying arguments between doctors and families to arrive at the most appropriate decision. Yet, it is still largely unknown how doctors and families argue in real-life conversations. This study aimed to (1) identify which arguments doctors and families use in support of standpoints to continue or discontinue LST, (2) investigate how doctors and families structure their arguments, and (3) explore how their argumentative practices unfold during conversations. Method: A qualitative inductive thematic analysis of 101 audio-recorded conversations between doctors and families. Results: Seventy-one doctors and the families of 36 patients from the neonatal, pediatric, and adult ICU (respectively, N-ICU, P-ICU, and A-ICU) of a large university-based hospital participated. In almost all conversations, doctors were the first to argue and families followed, thereby either countering the doctor’s line of argumentation or substantiating it. Arguments put forward by doctors and families fell under one of ten main types. The types of arguments presented by families largely overlapped with those presented by doctors. A real exchange of arguments occurred in a minority of conversations and was generally quite brief in the sense that not all possible arguments were presented and then discussed together. Conclusion: This study offers a detailed insight in the argumentation practices of doctors and families, which can help doctors to have a sharper eye for the arguments put forward by doctors and families and to offer room for true deliberation.

Background: The majority of patients admitted to the intensive care unit (ICU) experience severe hypotension which is associated with increased morbidity and mortality. At present, prospective studies examining the incidence and severity of hypotension using continuous waveforms are missing. Methods: This study is a prospective observational cohort study in a mixed surgical and non-surgical ICU population. All patients over 18 years were included and continuous arterial pressure waveforms data were collected. Mean arterial pressure (MAP) below 65 mmHg for at least 10 s was defined as hypotension and a MAP below 45 mmHg as severe hypotension. The primary outcome was the incidence of hypotension. Secondary outcomes were the severity of hypotension expressed in time-weighted average (TWA), factors associated with hypotension, the number and duration of hypotensive events. Results: 499 patients were included. The incidence of hypotension (MAP < 65 mmHg) was 75% (376 out of 499) and 9% (46 out of 499) experienced severe hypotension. Median TWA was 0.3 mmHg [0–1.0]. Associated clinical factors were age, male sex, BMI and cardiogenic shock. There were 5 (1–12) events per patients with a median of 52 min (5–170). Conclusions: In a mixed surgical and non-surgical ICU population the incidence of hypotension is remarkably high.

Background Mechanical ventilation with low tidal volumes has the potential to mitigate ventilation-induced lung injury, yet the clinical effect of tidal volume size on myocardial function has not been clarified. This cross-sectional study investigated whether low tidal volume ventilation has beneficial effects on myocardial systolic and diastolic function compared to intermediate tidal volume ventilation. Methods Forty-two mechanically ventilated patients without acute respiratory distress syndrome (ARDS) underwent transthoracic echocardiography after more than 24 h of mechanical ventilation according to the Protective Ventilation in Patients without ARDS (PReVENT) trial comparing a low versus intermediate tidal volume strategy. The primary outcome was left ventricular and right ventricular myocardial performance index as measure for combined systolic and diastolic function, with lower values indicating better myocardial function and a right ventricular myocardial performance index greater than 0.54 regarded as the abnormality threshold. Secondary outcomes included specific systolic and diastolic parameters. Results One patient was excluded due to insufficient acoustic windows, leaving 21 patients receiving low tidal volumes with a tidal volume size (mean ± SD) of 6.5 ± 1.8 ml/kg predicted body weight, while 20 patients were subjected to intermediate tidal volumes receiving a tidal volume size of 9.5 ± 1.6 ml/kg predicted body weight (mean difference, −3.0 ml/kg; 95% CI, −4.1 to −2.0; P < 0.001). Right ventricular dysfunction was reduced in the low tidal volume group compared to the intermediate tidal volume group (myocardial performance index, 0.41 ± 0.13 vs. 0.64 ± 0.15; mean difference, −0.23; 95% CI, −0.32 to −0.14; P < 0.001) as was left ventricular dysfunction (myocardial performance index, 0.50 ± 0.17 vs. 0.63 ± 0.19; mean difference, −0.13; 95% CI, −0.24 to −0.01; P = 0.030). Similarly, most systolic parameters were superior in the low tidal volume group compared to the intermediate tidal volume group, yet diastolic parameters did not differ between both groups. Conclusions In patients without ARDS, intermediate tidal volume ventilation decreased left ventricular and right ventricular systolic function compared to low tidal volume ventilation, although without an effect on diastolic function. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

The aim of this study was to investigate whether lower PEEP (positive end-expiratory pressure) had beneficial effects on myocardial function among intensive care unit (ICU) patients without acute respiratory distress syndrome (ARDS) compared to higher PEEP. In this pre-planned substudy of a randomized controlled trial (RELAx), comparing lower to higher PEEP, 44 patients underwent transthoracic echocardiography. The exclusion criteria were known poor left ventricular function and severe shock requiring high dosages of norepinephrine. To create contrast, we also excluded patients who received PEEP between 2 cmH2O and 7 cmH2O in the two randomization arms of the study. The primary outcome was the right ventricular myocardial performance index (MPI), a measure of systolic and diastolic function. The secondary outcomes included systolic and diastolic function parameters. A total of 20 patients were ventilated with lower PEEP (mean ± SD, 0 ± 1 cmH2O), and 24 patients, with higher PEEP (8 ± 1 cmH2O) (mean difference, −8 cmH2O; 95% CI: −8.1 to −7.9 cmH2O; p = 0.01). The tidal volume size was low in both groups (median (IQR), 7.2 (6.3 to 8.1) versus 7.0 (5.3 to 9.1) ml/kg PBW; p = 0.97). The median right ventricular MPI was 0.32 (IQR, 0.26 to 0.39) in the lower-PEEP group versus 0.38 (0.32 to 0.41) in the higher-PEEP group; the median difference was –0.03; 95% CI: −0.11 to 0.03; p = 0.33. The other systolic and diastolic parameters were similar. In patients without ARDS ventilated with a low tidal volume, a lower PEEP had no beneficial effects on the right ventricular MPI.

INTRODUCTION: Hypotension in the ICU is common, yet management is challenging and variable. Insight in management by ICU physicians and nurses may improve patient care and guide future hypotension treatment trials and guidelines.METHODS: We conducted an international survey among ICU personnel to provide insight in monitoring, management, and perceived consequences of hypotension.RESULTS: Out of 1464 respondents, 1197 (81.7%) were included (928 physicians (77.5%) and 269 nurses (22.5%)). The majority indicated that hypotension is underdiagnosed (55.4%) and largely preventable (58.8%). Nurses are primarily in charge of monitoring changes in blood pressure, physicians are in charge of hypotension treatment. Balanced crystalloids, dobutamine, norepinephrine, and Trendelenburg position were the most frequently reported fluid, inotrope, vasopressor, and positional maneuver used to treat hypotension. Reported complications believed to be related to hypotension were AKI and myocardial injury. Most ICUs do not have a specific hypotension treatment guideline or protocol (70.6%), but the majority would like to have one in the future (58.1%).CONCLUSIONS: Both physicians and nurses report that hypotension in ICU patients is underdiagnosed, preventable, and believe that hypotension influences morbidity. Hypotension management is generally not protocolized, but the majority of respondents would like to have a specific hypotension management protocol.

The objective of the study was to determine the association between right ventricular (RV) myocardial performance index (MPI) and successful liberation from the ventilator and death within 28 days.A total of 81 patients underwent transthoracic echocardiography at median 30 (24-42) h after the start of ventilation-in 73 (90%) patients, the RV-MPI could be collected. A total of 56 (77%) patients were successfully liberated from the ventilator28 days; A total of 22 (30%) patients had died before or at day 28. A total of 18 (25%) patients had an abnormal RV-MPI. RV-MPI was neither associated with successful liberation from the ventilator within 28 days [HR, 2.2 (95% CI 0.47-10.6);In invasively ventilated critically ill patients without ARDS, an abnormal RV-MPI indicative of RV dysfunction was not associated with time to liberation from invasive ventilation.

Background: Intensive care doctors have to find the right balance between sharing crucial decisions with families of patients on the one hand and not overburdening them on the other hand. This requires a tailored approach instead of a model based approach. Aim: To explore how doctors involve families in the decision-making process regarding life-sustaining treatment on the neonatal, pediatric, and adult intensive care. Design: Exploratory inductive thematic analysis of 101 audio-recorded conversations. Setting/participants: One hundred four family members (61% female, 39% male) and 71 doctors (60% female, 40% male) of 36 patients (53% female, 47% male) from the neonatal, pediatric, and adult intensive care of a large university medical center participated. Results: We identified eight relevant and distinct communicative behaviors. Doctors’ sequential communicative behaviors either reflected consistent approaches—a shared approach or a physician-driven approach—or reflected vacillating between both approaches. Doctors more often displayed a physician-driven or a vacillating approach than a shared approach, especially in the adult intensive care. Doctors did not verify whether their chosen approach matched the families’ decision-making preferences. Conclusions: Even though tailoring doctors’ communication to families’ preferences is advocated, it does not seem to be integrated into actual practice. To allow for true tailoring, doctors’ awareness regarding the impact of their communicative behaviors is key. Educational initiatives should focus especially on improving doctors’ skills in tactfully exploring families’ decision-making preferences and in mutually sharing knowledge, values, and treatment preferences.

Introduction: Although hypotension in ICU patients is associated with adverse outcome, currently used definitions are unknown and no universally accepted definition exists. Methods: We conducted an international, peer-reviewed survey among ICU physicians and nurses to provide insight in currently used definitions, estimations of incidence, and duration of hypotension. Results: Out of 1394 respondents (1055 physicians (76%) and 339 nurses (24%)), 1207 (82%) completed the questionnaire. In all patient categories, hypotension definitions were predominantly based on an absolute MAP of 65 mmHg, except for the neuro(trauma) category (75 mmHg, p < 0.001), without differences between answers from physicians and nurses. Hypotension incidence was estimated at 55%, and time per day spent in hypotension at 15%, both with nurses reporting higher percentages than physicians (estimated mean difference 5%, p = 0.01; and 4%, p < 0.001). Conclusions: An absolute MAP threshold of 65 mmHg is most frequently used to define hypotension in ICU patients. In neuro(trauma) patients a higher threshold was reported. The majority of ICU patients are estimated to endure hypotension during their ICU admission for a considerable amount of time, with nurses reporting a higher estimated incidence and time spent in hypotension than physicians.

Introduction: Previous studies demonstrated the cardioprotective properties of glucagon-like peptide-1 receptor agonists in patients with diabetes or cardiac disease. We investigated whether preoperative subcutaneous liraglutide improves myocardial function after cardiac surgery. Methods: We performed a pre-planned secondary analysis of adult patients undergoing cardiac surgery included in the GLOBE trial. Patients were randomised to receive 0.6 mg subcutaneous liraglutide on the evening before surgery and 1.2 mg after induction of anaesthesia, or matching placebo. Perioperative echocardiographic assessments, haemodynamic parameters, doses of vasoactive inotropic support and postoperative measurements of troponin, Creatine Kinase-MB , creatinine and lactate were compared between groups. Results: The study population consisted of the entire intention-to-treat cohort of the GLOBE trial. In this study, 129 patients received liraglutide and 132 patients placebo. Baseline characteristics were comparable between groups. Postoperatively, 170 (65%) patients underwent echocardiography. In the liraglutide group, more patients had a normal left ventricular systolic function (68%, 59 patients) compared to placebo (53%, 44 patients), difference = 15%, 95%CI = 0&ndash, 30, p = 0.049. Assessment of the right ventricle revealed no difference in function. Conclusions: Patients receiving short-term preoperative liraglutide treatment better maintained normal myocardial function after cardiac surgery. This study warrants further evaluation of the potential beneficial effects of GLP-1 receptor agonists in cardiac surgery patients.

Lung ultrasound (LUS) is a non-invasive bedside method used to quantify extravascular lung water (EVLW). To evaluate the methodology and diagnostic accuracy of LUS in studies assessing EVLW in intensive care unit patients, PubMed and Embase were searched for studies comparing LUS with imaging modalities. In 14 relevant studies a wide variety of equipment used and training of examiners were noted. Four scoring systems were reported: (i) a binary score (the presence of three or more B-lines); (ii) a categorical score; (iii) a numerical score; (iv) a quantitative LUS score using software. The diagnostic accuracy of LUS varied: sensitivity ranged from 50%–98%, specificity from 76%–100% and r² from 0.20–0.91. Methodology and diagnostic accuracy varies substantially in published reports. Further research is needed to correlate methodological factors with diagnostic accuracy. Hospitals should standardize LUS methodology. Consensus is needed to harmonize LUS methodology for lung water assessment.

Aims: Mortality in cardiogenic shock patients remains high. Short-term mechanical circulatory support with Impella can be used to support the circulation in these patients, but data from randomised controlled studies and ‘real-world’ data are sparse. The aim is to describe real-life data on outcomes and complications of our 12 years of clinical experience with Impella in patients with cardiogenic shock after acute myocardial infarction and to identify predictors of 6-month mortality. Methods: We describe a single-centre registry from October 2004 to December 2016 including all patients treated with Impella for cardiogenic shock after acute myocardial infarction. We report outcomes and complications and identify predictors of 6-month mortality. Results: Our overall clinical experience consists of 250 patients treated with Impella 2.5, Impella CP or Impella 5.0. A total of 172 patients received Impella therapy for cardiogenic shock, of which 112 patients had cardiogenic shock after acute myocardial infarction. The mean age was 60.1±10.6 years, mean arterial pressure was 67 (56–77) mmHg, lactate was 6.2 (3.6–9.7) mmol/L, 87.5% were mechanically ventilated and 59.6% had a cardiac arrest before Impella placement. Overall 30-day mortality was 56.2% and 6-month mortality was 60.7%. Complications consisted of device-related vascular complications (17.0%), non-device-related bleeding (12.5%), haemolysis (7.1%) and stroke (3.6%). In a multivariate analysis, pH before Impella placement is a predictor of 6-month mortality. Conclusions: Our registry shows that Impella treatment in cardiogenic shock after acute myocardial infarction is feasible, although mortality rates remain high and complications occur.

Veno-arterial extracorporeal life support (ECLS) is increasingly used in patients during cardiac arrest and cardiogenic shock, to support both cardiac and pulmonary function. We performed a systematic review and meta-analysis of cohort studies comparing mortality in patients treated with and without ECLS support in the setting of refractory cardiac arrest and cardiogenic shock complicating acute myocardial infarction. We systematically searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and the publisher subset of PubMed updated to December 2015. Thirteen studies were included of which nine included cardiac arrest patients (n = 3098) and four included patients with cardiogenic shock after acute myocardial infarction (n = 235). Data were pooled by a Mantel-Haenzel random effects model and heterogeneity was examined by the I (2) statistic. In cardiac arrest, the use of ECLS was associated with an absolute increase of 30 days survival of 13 % compared with patients in which ECLS was not used [95 % CI 6-20 %; p < 0.001; number needed to treat (NNT) 7.7] and a higher rate of favourable neurological outcome at 30 days (absolute risk difference 14 %; 95 % CI 7-20 %; p < 0.0001; NNT 7.1). Propensity matched analysis, including 5 studies and 438 patients (219 in both groups), showed similar results. In cardiogenic shock, ECLS showed a 33 % higher 30-day survival compared with IABP (95 % CI, 14-52 %; p < 0.001; NNT 13) but no difference when compared with TandemHeart/Impella (-3 %; 95 % CI -21 to 14 %; p = 0.70; NNH 33). In cardiac arrest, the use of ECLS was associated with an increased survival rate as well as an increase in favourable neurological outcome. In the setting of cardiogenic shock there was an increased survival with ECLS compared with IABP

We present a female patient with severe acute respiratory distress syndrome (ARDS) necessitating intubation and mechanical ventilation on the intensive care unit (ICU). High ventilatory pressures were needed because of hypoxia and severe hypercapnia with respiratory acidosis, resulting in right ventricular dysfunction with impaired haemodynamic stability. A veno-venous extracorporeal CO2 removal (ECCO2R) circuit was initiated, effectively eliminating carbon dioxide while improving oxygenation and enabling a reduction in applied ventilatory pressures. We noted a marked improvement of right ventricular function with restoration of haemodynamic stability. Within one week, the patient was weaned from both ECCO2R and mechanical ventilation. Besides providing adequate gas exchange, extracorporeal assist devices may be helpful in ameliorating right ventricular dysfunction during ARDS.

Study objective: The mini-fluid challenge may predict fluid responsiveness with minimum risk of fluid overloading. However, the amount of fluid as well as the best manner to evaluate the effect is unclear. In this prospective observational pilot study, the value of changes in pulse contour cardiac output (CO) measurements during mini-fluid challenges is investigated. Design: Prospective observational study. Setting: Intensive Care Unit of a university hospital. Patients: Twenty-one patients directly after elective cardiac surgery on mechanical ventilation. Interventions: The patients were subsequently given 10 intravenous boluses of 50 mL of hydroxyethyl starch with a total of 500 mL per patient while measuring pulse contour CO. Measurements: We measured CO by minimal invasive ModelflowR (COm) and PulseCOR (COli), before and one minute after each fluid bolus. We analyzed the smallest volume that was predictive of fluid responsiveness. A positive fluid response was defined as an increase in CO of > 10% after 500 mL fluid infusion. Main results: Fifteen patients (71%) were COm responders and 13 patients (62%) COli responders. An increase in COm after 150 mL of fluid > 5.0% yielded a positive and negative predictive value (+ PV and − PV) of 100% with an area under the curve (AUC) of 1.00 (P < 0.001). An increase in COli > 6.3% after 200 mL was able to predict a fluid response in COli after 500 mL with a + PV of 100% and − PV of 73%, with an AUC of 0.88 (P < 0.001). Conclusion: The use of minimal invasive ModelflowR pulse contour CO measurements following a mini-fluid challenge of 150 mL can predict fluid responsiveness and may help to improve fluid management.

Objective: Passive leg raising creates a reversible increase in venous return allowing for the prediction of fluid responsiveness. However, the amount of venous return may vary in various clinical settings potentially affecting the diagnostic performance of passive leg raising. Therefore we performed a systematic meta-analysis determining the diagnostic performance of passive leg raising in different clinical settings with exploration of patient characteristics, measurement techniques, and outcome variables. Data Sources: PubMed, EMBASE, the Cochrane Database of Systematic Reviews, and citation tracking of relevant articles. Study Selection: Clinical trials were selected when passive leg raising was performed in combination with a fluid challenge as gold standard to define fluid responders and non-responders. Data Extraction: Trials were included if data were reported allowing the extraction of sensitivity, specificity, and area under the receiver operating characteristic curve. Data Synthesis: Twenty-three studies with a total of 1,013 patients and 1,034 fluid challenges were included. The analysis demonstrated a pooled sensitivity of 86% (95% CI, 79-92), pooled specificity of 92% (95% CI, 88-96), and a summary area under the receiver operating characteristic curve of 0.95 (95% CI, 0.92-0.98). Mode of ventilation, type of fluid used, passive leg raising starting position, and measurement technique did not affect the diagnostic performance of passive leg raising. The use of changes in pulse pressure on passive leg raising showed a lower diagnostic performance when compared with passive leg raising induced changes in flow variables, such as cardiac output or its direct derivatives (sensitivity of 58% [95% CI, 44-70] and specificity of 83% [95% CI, 68-92] vs sensitivity of 85% [95% CI, 78-90] and specificity of 92% [95% CI, 87-94], respectively; p < 0.001). Conclusions: Passive leg raising retains a high diagnostic performance in various clinical settings and patient groups. The predictive value of a change in pulse pressure on passive leg raising is inferior to a passive leg raising induced change in a flow variable.

It is well-known that positive end-expiratory pressure (PEEP) can prevent ventilator-induced lung injury (VILI) and improve pulmonary physiology in animals with injured lungs. It's uncertain whether PEEP has similar effects in animals with uninjured lungs. A systematic review of randomized controlled trials (RCTs) comparing different PEEP levels in animals with uninjured lungs was performed. Trials in animals with injured lungs were excluded, as were trials that compared ventilation strategies that also differed with respect to other ventilation settings, e.g., tidal volume size. The search identified ten eligible trials in 284 animals, including rodents and small as well as large mammals. Duration of ventilation was highly variable, from 1 to 6 hours and tidal volume size varied from 7 to 60 mL/kg. PEEP ranged from 3 to 20 cmH2O, and from 0 to 5 cmH2O, in the 'high PEEP' or 'PEEP' arms, and in the 'low PEEP' or 'no PEEP' arms, respectively. Definitions used for lung injury were quite diverse, as were other outcome measures. The effects of PEEP, at any level, on lung injury was not straightforward, with some trials showing less injury with 'high PEEP' or 'PEEP' and other trials showing no benefit. In most trials, 'high PEEP' or 'PEEP' was associated with improved respiratory system compliance, and better oxygen parameters. However, 'high PEEP' or 'PEEP' was also associated with occurrence of hypotension, a reduction in cardiac output, or development of hyperlactatemia. There were no differences in mortality. The number of trials comparing 'high PEEP' or 'PEEP' with 'low PEEP' or 'no PEEP' in animals with uninjured lungs is limited, and results are difficult to compare. Based on findings of this systematic review it's uncertain whether PEEP, at any level, truly prevents lung injury, while most trials suggest potential harmful effects on the systemic circulation.

The mini-fluid challenge may predict fluid responsiveness with minimum risk of fluid overloading. However, the amount of fluid as well as the best manner to evaluate the effect is unclear. In this prospective observational pilot study, the value of changes in pulse contour cardiac output (CO) measurements during mini-fluid challenges is investigated.Prospective observational study.Intensive Care Unit of a university hospital.Twenty-one patients directly after elective cardiac surgery on mechanical ventilation.The patients were subsequently given 10 intravenous boluses of 50mL of hydroxyethyl starch with a total of 500mL per patient while measuring pulse contour CO.We measured CO by minimal invasive ModelflowFifteen patients (71%) were COm responders and 13 patients (62%) COli responders. An increase in COm after 150mL of fluid5.0% yielded a positive and negative predictive value (+PV and -PV) of 100% with an area under the curve (AUC) of 1.00 (P0.001). An increase in COli6.3% after 200mL was able to predict a fluid response in COli after 500mL with a +PV of 100% and -PV of 73%, with an AUC of 0.88 (P0.001).The use of minimal invasive Modelflow

1. The present study examined the relationship between centrally measured stroke volume variation (SVV) and peripherally derived pulse pressure variation (PPV) in the setting of increased total arterial compliance (CA rt ). 2. Ten male Wistar rats were anaesthetized, paralysed and mechanically ventilated before being randomized to receive intrapulmonary lipopolysaccharide (LPS) or no LPS. Pulse pressure (PP) was derived from the left carotid artery, whereas stroke volume (SV) was measured directly in the left ventricle. Values of SVV and PPV were calculated over three breaths. Balloon inflation of a catheter positioned in the inferior vena cava was used, for a maximum of 30 s, to decrease preload while the SVV and PPV measurements were repeated. Values of CA rt were calculated as SV/PP. 3. Intrapulmonary LPS increased CA rt and SV. Values of SVV and PPV increased in both LPS-treated and untreated rats during balloon inflation. There was a correlation between SVV and PPV in untreated rats before (r = 0.55; P = 0.005) and during (r = 0.69; P < 0.001) occlusion of the vena cava. There was no such correlation in LPS-treated rats either before (r = -0.08; P = 0.70) or during (r = 0.36; P = 0.08) vena cava occlusion. 4. In conclusion, under normovolaemic and hypovolaemic conditions, PPV does not reflect SVV during an increase in CA rt following LPS-induced pneumonia in mechanically ventilated rats. Our data caution against their interchangeability in human sepsis.

Predicting fluid responsiveness, the response of stroke volume to fluid loading, is a relatively novel concept that aims to optimise circulation, and as such organ perfusion, while avoiding futile and potentially deleterious fluid administrations in critically ill patients. Dynamic parameters have shown to be superior in predicting the response to fluid loading compared with static cardiac filling pressures. However, in routine clinical practice the conditions necessary for dynamic parameters to predict fluid responsiveness are frequently not met. Passive leg raising as a means to alter biventricular preload in combination with subsequent measurement of the change in stroke volume can provide a fast and accurate way to guide fluid management in a broad population of critically ill patients.

Cardiopulmonary interactions induced by mechanical ventilation are complex and only partly understood. Applied tidal volumes and/or airway pressures largely mediate changes in right ventricular preload and afterload. Effects on left ventricular function are mostly secondary to changes in right ventricular loading conditions. It is imperative to dissect the several causes of haemodynamic compromise during mechanical ventilation as undiagnosed ventricular dysfunction may contribute to morbidity and mortality.

Background Ventilator-induced dynamic hemodynamic parameters such as stroke volume variation (SVV) and pulse pressure variation (PPV) have been shown to predict fluid responsiveness in contrast to static hemodynamic parameters such as central venous pressure (CVP). We hypothesized that the ventilator-induced central venous pressure variation (CVPV) could predict fluid responsiveness. Methods Twenty-two elective cardiac surgery patients were studied post-operatively on the intensive care unit during mechanical ventilation with tidal volumes of 6–8 ml/kg without spontaneous breathing efforts or cardiac arrhythmia. Before and after administration of 500mL hydroxyethyl starch, SVV and PPV were measured using pulse contour analysis by modified Modelflow®, while CVP was obtained from a central venous catheter positioned in the superior vena cava. CVPV was calculated as 100 × (CVPmax−CVPmin)/[(CVPmax + CVPmin)/2]. Results Nineteen patients (86%) were fluid responders defined as an increase in cardiac output of ≥ 15% after fluid administration. CVPV decreased upon fluid loading in responders, but not in non-responders. Baseline CVP values showed no correlation with a change in cardiac output in contrast to baseline SVV (r = 0.60, P = 0.003), PPV (r = 0.58, P = 0.005), and CVPV (r = 0.63, P = 0.002). Baseline values of SVV > 9% and PPV > 8% could predict fluid responsiveness with a sensitivity of 89% and 95%, respectively, both with a specificity of 100%. Baseline CVPV could identify all fluid responders and non-responders correctly at a cut-off value of 12%. There was no difference between the area under the receiver operating characteristic curves of SVV, PPV, and CVPV. Conclusion The use of ventilator-induced CVPV could predict fluid responsiveness similar to SVV and PPV in post-operative cardiac surgery patients.

The objective of the present study was to test the hypothesis that controlled, adequately compensated, central hypovolemia in subjects with intact autoregulation would be associated with decreased peripheral microcirculatory diffusion and convection properties and, consequently, decreased tissue oxygen carrying capacity and tissue oxygenation. Furthermore, we evaluated the impact of hypovolemia-induced microcirculatory alterations on resting tissue oxygen consumption. To this end, 24 subjects were subjected to a progressive lower body negative pressure (LBNP) protocol of which 14 reached the end of the protocol. At baseline and at LBNP = − 60 mm Hg, sidestream dark field (SDF) images of the sublingual microcirculation were acquired to measure microvascular density and perfusion; thenar and forearm tissue hemoglobin content (THI) and tissue oxygenation (StO2) were recorded using near-infrared spectroscopy (NIRS); and a vascular occlusion test (VOT) was performed to assess resting tissue oxygen consumption rate. SDF images were analyzed for total vessel density (TVD), perfused vessel density (PVD), the microvascular flow index (MFI), and flow heterogeneity (MFIhetero). We found that application of LBNP resulted in: 1) a significantly decreased microvascular density (PVD) and perfusion (MFI and MFIhetero); 2) a significantly decreased THI and StO2; and 3) an unaltered resting tissue oxygen consumption rate. In conclusion, using SDF imaging in combination with NIRS we showed that controlled, adequately compensated, central hypovolemia in subjects with intact autoregulation is associated with decreased microcirculatory diffusion (PVD) and convection (MFI and MFIhetero) properties and, consequently, decreased tissue oxygen carrying capacity (THI) and tissue oxygenation (StO2). Furthermore, using a VOT we found that resting tissue oxygen consumption was maintained under conditions of adequately compensated central hypovolemia.

Exercise testing is often used to assess cardiac function during physical exertion to obtain diagnostic information. However, this procedure is limited to measuring the electrical activity of the heart using electrocardiography and intermittent blood pressure (BP) measurements and does not involve the continuous assessment of heart functioning. In this study, we compared continuous beat-to-beat pulse contour analysis to monitor noninvasive cardiac output (CO) during exercise with inert gas rebreathing and respired gas analysis. Nineteen healthy male volunteers were subjected to bicycle ergometry testing with increasing workloads. Cardiac output was deter- mined noninvasively by continuous beat-to-beat pulse contour analysis (Nexfin) and by inert gas rebreathing, and estimated using the respired gas analysis method. The effects of the rebreathing maneuver on heart rate (HR), stroke volume (SV), and CO were evaluated. The CO values derived from the Nexfin- and inert gas rebreathing methods were well correlated (r = 0.88, P < 0.01) and the limits of agreement were 30.3% with a measurement bias of 0.4 ± 1.8 L/min. Nexfin- and respired gas analysis-derived CO values correlated even better (r = 0.94, P < 0.01) and the limits of agreement were 21.5% with a measurement bias of -0.70 ± 1.6 L/min. At rest, the rebreathing maneuver increased HR by 13 beats/min (P < 0.01), SV remained unaffected (P = 0.7), while CO increased by 1.0 L/min (P < 0.01). Rebreathing did not affect these parameters during exercise. Nexfin continuous beat-to-beat pulse contour analysis is an appropriate method for noninvasive assessment of CO during exercise

Purpose To test the hypothesis that the sensitivity of near-infrared spectroscopy (NIRS) in reflecting the degree of (compensated) hypovolemia would be affected by the application site and probing depth. We simultaneously applied multi-site (thenar and forearm) and multi-depth (15–2.5 and 25–2.5 mm probe distance) NIRS in a model of simulated hypovolemia: lower body negative pressure (LBNP). Methods The study group comprised 24 healthy male volunteers who were subjected to an LBNP protocol in which a baseline period of 30 min was followed by a step-wise manipulation of negative pressure in the following steps: 0, −20, −40, −60, −80 and −100 mmHg. Stroke volume and heart rate were measured using volume-clamp finger plethysmography. Two multi-depth NIRS devices were used to measure tissue oxygen saturation (StO2) and tissue hemoglobin index (THI) continuously in the thenar and the forearm. To monitor the shift of blood volume towards the lower extremities, calf THI was measured by single-depth NIRS. Results The main findings were that the application of LBNP resulted in a significant reduction in stroke volume which was accompanied by a reduction in forearm StO2 and THI. Conclusions NIRS can be used to detect changes in StO2 and THI consequent upon central hypovolemia. Forearm NIRS measurements reflect hypovolemia more sensitively than thenar NIRS measurements. The sensitivity of these NIRS measurements does not depend on NIRS probing depth. The LBNP-induced shift in blood volume is reflected by a decreased THI in the forearm and an increased THI in the calf. Electronic supplementary material The online version of this article (doi:10.1007/s00134-010-2128-6) contains supplementary material, which is available to authorized users.

Objectives: To examine the effect of positive end-expiratory pressure (PEEP) on right ventricular stroke volume variation (SW), with possible implications for the number and timing of pulmonary artery catheter thermodilution measurements. Design: Prospective, clinical pilot study. Setting: Academic medical center. Participants: Patients who underwent volume-controlled mechanical ventilation and had a pulmonary artery catheter. Intervention: PEEP was increased from 5-to-10 cmH(2)O and from 10-to-15 cmH(2)O with 10-minute intervals, with similar decreases in PEEP, from 15-to-10 cmH(2)O and 10-to-5 cmH(2)O. Measurements and Main Results: In 15 patients, right ventricular parameters were measured using thermodilution at 10% intervals of the ventilatory cycle at each PEEP level with a rapid-response thermistor. Mean right ventricular stroke volume and end-diastolic volume declined during incremental PEEP and normalized on return to 5 cmH(2)O PEEP (p = 0.01 and p = 0.001, respectively). Right ventricular SW remained unaltered by changes in PEEP (p = 0.26), regardless of incremental PEEP (p = 0.15) or decreased PEEP (p = 0.12). The coefficients of variation in the ventilatory cycle of all other thermodilution-derived right ventricular parameters also were unaffected by changes in PEEP. Conclusions: This study showed that increases in PEEP did not affect right ventricular SW in critically ill patients undergoing mechanical ventilation despite reductions in mean right ventricular stroke volume and end-diastolic volume. This could be explained by cyclic counteracting changes in right ventricular preloading and afterloading during the ventilatory cycle, independent of PEEP. Changes in PEEP did not affect the number and timing of pulmonary artery catheter thermodilution measurements. (C) 2016 Elsevier Inc. All rights reserved.

Commentary on: Bentzer P, Griesdale DE, Boyd J, et al. Will this hemodynamically unstable patient respond to a bolus of intravenous fluids? JAMA 2016;316:1298–309.[OpenUrl][1] Administration of intravenous fluids still serves as the cornerstone of haemodynamic resuscitation, yet both insufficient as well as overzealous fluid loading can increase morbidity and mortality. Correctly predicting fluid responsiveness is thus of the utmost importance, especially since only half of critically ill patients positively respond to a fluid bolus. Bentzer et al investigated the diagnostic performance of different methods in predicting fluid responsiveness. Using MEDLINE and EMBASE, a total of 651 studies were identified investigating different methods to predict fluid responsiveness in haemodynamic unstable patients with refractory hypotension and/or signs of organ hypoperfusion. After exclusion of lower quality studies, trials with ≤20 patients and studies performed in elective cardiothoracic surgery patients, a systematic review and … [1]: {openurl}?query=rft.jtitle%253DJAMA%26rft.volume%253D316%26rft.spage%253D1298%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx

Background: High tidal volume ventilation has shown to cause ventilator-induced lung injury (VILI), possibly contributing to concomitant extrapulmonary organ dysfunction. The present study examined whether left ventricular (LV) function is dependent on tidal volume size and whether this effect is augmented during lipopolysaccharide(LPS)-induced lung injury. Methods: Twenty male Wistar rats were sedated, paralyzed and then randomized in four groups receiving mechanical ventilation with tidal volumes of 6 ml/ kg or 19 ml/kg with or without intrapulmonary administration of LPS. A conductance catheter was placed in the left ventricle to generate pressure-volume loops, which were also obtained within a few seconds of vena cava occlusion to obtain relatively load-independent LV systolic and diastolic function parameters. The end-systolic elastance / effective arterial elastance (Ees/Ea) ratio was used as the primary parameter of LV systolic function with the end-diastolic elastance (Eed) as primary LV diastolic function. Results: Ees/Ea decreased over time in rats receiving LPS (p = 0.045) and high tidal volume ventilation (p = 0.007), with a lower Ees/Ea in the rats with high tidal volume ventilation plus LPS compared to the other groups (p < 0.001). Eed increased over time in all groups except for the rats receiving low tidal volume ventilation without LPS (p = 0.223). A significant interaction (p < 0.001) was found between tidal ventilation and LPS for Ees/Ea and Eed, and all rats receiving high tidal volume ventilation plus LPS died before the end of the experiment. Conclusions: Low tidal volume ventilation ameliorated LV systolic and diastolic dysfunction while preventing death following LPS-induced lung injury in mechanically ventilated rats. Our data advocates the use of low tidal volumes, not only to avoid VILI, but to avert ventilator-induced myocardial dysfunction as well.

FLUID RESPONSIVENESS is a strategy used to select patients who will respond with a positive reaction in a physiologic parameter upon fluid administration. Curiously, there is no generally accepted definition of fluid responsiveness. A provisional definition of fluid responsiveness would be “the positive reaction of a physiologic parameter of a certain size to a standardized volume of a certain type of fluid administered within a certain amount of time and measured within a certain interval.” It is clear that these issues need to be resolved before a more detailed and precise definition can be proposed. The aim of predicting fluid responsiveness is to achieve this positive reaction while using the least amount of fluids. Accurate prediction of fluid responsiveness to facilitate patient-tailored fluid titration is crucial, as it has been shown that only half of critically ill patients will respond to fluid loading with an increase in cardiac output. Moreover, unnecessary fluid administration has shown to increase morbidity, mortality, and hospital and intensive care stays. Over the last decade, the rise in the number of publications about fluid responsiveness in the intensive care and operating room has shown the increased interest in this topic. In this review, the authors describe the physiology, requirements, and limitations of fluid responsiveness. Subsequently, using available literature, a practical definition on fluid responsiveness is proposed. The reliability of clinical, static, and hemodynamic parameters is evaluated to predict the response to fluid loading in critically ill patients. Finally, the potential, shortcomings, and use of passive leg raising are discussed in this review.

Veno-arterial extracorporeal life support (ECLS) is increasingly used in patients during cardiac arrest and cardiogenic shock, to support both cardiac and pulmonary function. We performed a systematic review and meta-analysis of cohort studies comparing mortality in patients treated with and without

A previously healthy 80-year-old male with a history of type II diabetes mellitus was referred to our emergency department because of severe dyspnoea. Physical examination revealed a diaphoretic man with a blood pressure of 105/65 mmHg, a low oxygen saturation of 85% and diffuse inspiratory crackles and rales on auscultation. The electrocardiogram showed a sinus tachycardia of 110 beats/min with a left bundle branch block. A chest X-ray of the lungs revealed pulmonary oedema. Arterial blood gas analysis indicated respiratory acidosis requiring intubation and ventilation. Immediate transoesophageal echocardiography (TEE) was performed to search for signs of suspected acute ischaemia. The echocardiogram pointed out a dilated left ventricle with severe hypokinesia of all wall segments. There was a moderate secondary mitral regurgitation due to the left ventricular dysfunction and annular dilatation. The aortic valve appeared normal without any signs of stenosis. The echocardiogram suggested the presence of chronic heart failure until colour Doppler analysis of the aortic valve revealed a mosaic flow pattern in the left main coronary artery suggesting a severe stenosis (Fig. 1a). Urgent cardiac catheterisation confirmed a pinpoint stenosis of the left main coronary artery (Fig. 1b). Subsequently, coronary artery bypass grafting was performed with maximum CK-MB of 55 μg/L, and the patient recovered uneventfully. Fig. 1 a Colour Doppler analysis reveals mosaic flow in the left main coronary artery suggestive of a severe stenosis with the aortic valve showing no signs of obstruction; b In the LAO view the pinpoint left main coronary artery stenosis is confirmed Transthoracic echocardiography can adequately assess coronary flow in approximately half of patients [1]. Normally, the colour flow pattern in the coronary artery is consistent with laminar flow. Diastolic mosaic flow caused by focal flow acceleration indicates significant left main coronary artery stenosis in 85% of patients. Peak diastolic velocities greater than 1.5 m/s are considered abnormal [1]. TEE can visualise haemodynamically significant stenosis of the left main as well as primarily proximal segments of the left anterior descending, circumflex and right coronary artery in the majority of patients [2]. Our case stresses the diagnostic power of a carefully performed TEE in haemodynamically unstable patients of unknown cause.