Closed-Loop ventilation using sidestream versus mainstream capnography for automated adjustments of minute ventilation-A randomized clinical trial in cardiac surgery patients

BACKGROUND

INTELLiVENT-Adaptive Support Ventilation (ASV) is a closed-loop ventilation mode that uses capnography to adjust tidal volume (VT) and respiratory rate according to a user-set end-tidal CO2 (etCO2) target range. We compared sidestream versus mainstream capnography with this ventilation mode with respect to the quality of breathing in patients after cardiac surgery.

METHODS

Single-center, single-blinded, non-inferiority, randomized clinical trial in adult patients scheduled for elective cardiac surgery that were expected to receive at least two hours of postoperative ventilation in the ICU. Patients were randomized 1:1 to closed-loop ventilation with sidestream or mainstream capnography. Each breath was classified into a zone based on the measured VT, maximum airway pressure, etCO2 and pulse oximetry. The primary outcome was the proportion of breaths spent in a predefined 'optimal' zone of ventilation during the first three hours of postoperative ventilation, with a non-inferiority margin for the difference in the proportions set at -20%. Secondary endpoints included the proportion of breaths in predefined 'acceptable' and 'critical' zones of ventilation, and the proportion of breaths with hypoxemia.

RESULTS

Of 80 randomized subjects, 78 were included in the intention-to-treat analysis. We could not confirm the non-inferiority of closed-loop ventilation using sidestream with respect to the proportion of breaths in the 'optimal' zone (mean ratio 0.87 [0.77 to ∞]; P = 0.116 for non-inferiority). The proportion of breaths with hypoxemia was higher in the sidestream capnography group versus the mainstream capnography group.

CONCLUSIONS

We could not confirm that INTELLiVENT-ASV using sidestream capnography is non-inferior to INTELLiVENT-ASV using mainstream capnography with respect to the quality of breathing in subjects receiving postoperative ventilation after cardiac surgery.

TRIAL REGISTRATION

NCT04599491 (clinicaltrials.gov).

Characteristics, Treatment Strategies and Outcome in Cardiogenic Shock Complicating Acute Myocardial Infarction: A Contemporary Dutch Cohort

Cardiogenic shock (CS) complicating acute myocardial infarction (AMI) is associated with high morbidity and mortality. Our study aimed to gain insights into patient characteristics, outcomes and treatment strategies in CS patients. Patients with CS who underwent percutaneous coronary intervention (PCI) between 2017 and 2021 were identified in a nationwide registry. Data on medical history, laboratory values, angiographic features and outcomes were retrospectively assessed. A total of 2328 patients with a mean age of 66 years and of whom 73% were male, were included. Mortality at 30 days was 39% for the entire cohort. Non-survivors presented with a lower mean blood pressure and increased heart rate, blood lactate and blood glucose levels (p-value for all <0.001). Also, an increased prevalence of diabetes, multivessel coronary artery disease and a prior coronary event were found. Of all patients, 24% received mechanical circulatory support, of which the majority was via intra-aortic balloon pumps (IABPs). Furthermore, 79% of patients were treated with at least one vasoactive agent, and multivessel PCI was performed in 28%. In conclusion, a large set of hemodynamic, biochemical and patient-related characteristics was identified to be associated with mortality. Interestingly, multivessel PCI and IABPs were frequently applied despite a lack of evidence.

Effect of the machine learning-derived Hypotension Prediction Index (HPI) combined with diagnostic guidance versus standard care on depth and duration of intraoperative and postoperative hypotension in elective cardiac surgery patients: HYPE-2 - study protocol of a randomised clinical trial

INTRODUCTION

Hypotension 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 ANALYSIS

This 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 DISSEMINATION

The 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 NUMBER

The Netherlands Trial Register (NL9449), ClinicalTrials.gov (NCT05821647).

In-hospital and 6-month outcomes in patients with COVID-19 supported with extracorporeal membrane oxygenation (EuroECMO-COVID): a multicentre, prospective observational study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has been widely used in patients with COVID-19, but uncertainty remains about the determinants of in-hospital mortality and data on post-discharge outcomes are scarce. The aims of this study were to investigate the variables associated with in-hospital outcomes in patients who received ECMO during the first wave of COVID-19 and to describe the status of patients 6 months after ECMO initiation.

METHODS

EuroECMO-COVID is a prospective, multicentre, observational study developed by the European Extracorporeal Life Support Organization. This study was based on data from patients aged 16 years or older who received ECMO support for refractory COVID-19 during the first wave of the pandemic-from March 1 to Sept 13, 2020-at 133 centres in 21 countries. In-hospital mortality and mortality 6 months after ECMO initiation were the primary outcomes. Mixed-Cox proportional hazards models were used to investigate associations between patient and management-related variables (eg, patient demographics, comorbidities, pre-ECMO status, and ECMO characteristics and complications) and in-hospital deaths. Survival status at 6 months was established through patient contact or institutional charts review. This study is registered with ClinicalTrials.gov, NCT04366921, and is ongoing.

FINDINGS

Between March 1 and Sept 13, 2020, 1215 patients (942 [78%] men and 267 [22%] women; median age 53 years [IQR 46-60]) were included in the study. Median ECMO duration was 15 days (IQR 8-27). 602 (50%) of 1215 patients died in hospital, and 852 (74%) patients had at least one complication. Multiorgan failure was the leading cause of death (192 [36%] of 528 patients who died with available data). In mixed-Cox analyses, age of 60 years or older, use of inotropes and vasopressors before ECMO initiation, chronic renal failure, and time from intubation to ECMO initiation of 4 days or more were associated with higher in-hospital mortality. 613 patients did not die in hospital, and 547 (95%) of 577 patients for whom data were available were alive at 6 months. 102 (24%) of 431 patients had returned to full-time work at 6 months, and 57 (13%) of 428 patients had returned to part-time work. At 6 months, respiratory rehabilitation was required in 88 (17%) of 522 patients with available data, and the most common residual symptoms included dyspnoea (185 [35%] of 523 patients) and cardiac (52 [10%] of 514 patients) or neurocognitive (66 [13%] of 512 patients) symptoms.

INTERPRETATION

Patient's age, timing of cannulation (<4 days vs ≥4 days from intubation), and use of inotropes and vasopressors are essential factors to consider when analysing the outcomes of patients receiving ECMO for COVID-19. Despite post-discharge survival being favourable, persisting long-term symptoms suggest that dedicated post-ECMO follow-up programmes are required.

FUNDING

None.

Incidence, Severity and Clinical Factors Associated with Hypotension in Patients Admitted to an Intensive Care Unit: A Prospective Observational Study

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.

Abnormal Right Ventricular Myocardial Performance Index Is Not Associated With Outcomes in Invasively Ventilated Intensive Care Unit Patients Without Acute Respiratory Distress Syndrome—Post hoc Analysis of Two RCTs

Background

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.

Methods

Post hoc analysis of 2 ventilation studies in invasively ventilated patients not having ARDS. RV-MPI was collected through transthoracic echocardiography within 24–48 h from the start of invasive ventilation according to the study protocols. RV-MPI ≤ 0.54 was considered normal. The primary endpoint was successful liberation from the ventilator &lt; 28 days; the secondary endpoint was 28-day mortality.

Results

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 ventilator &lt; 28 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); p = 0.31] nor with 28-day mortality [HR, 1.56 (95% CI 0.07–34.27); p = 0.7].

Conclusion

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.

Incidence and risk factors of deep vein thrombosis after extracorporeal life support

Background

Deep vein thrombosis (DVT) after decannulation of extracorporeal life support (ECLS) is not uncommon. Moreover, the impact of anticoagulation and potential risk factors is unclear. Furthermore, it is unclear if cannula‐associated DVT is more common in ECLS patients compared to critically ill patients without ECLS.

Methods

All adult patients who were successfully weaned from ECLS and were screened for DVT following decannulation were included in this observational cohort study. The incidence of post‐ECLS‐DVT was assessed and the cannula‐associated DVT rate was compared with that of patients without ECLS after central venous catheter (CVC) removal. The correlation between the level of anticoagulation, risk factors, and post‐ECLS‐DVT was determined.

Results

We included 30 ECLS patients and 53 non‐ECLS patients. DVT was found in 15 patients (50%) of which 10 patients had a DVT in a cannulated vein. No correlation between the level of anticoagulation and DVT was found. V‐V ECLS mode was the only independent risk factor for post‐ECLS‐DVT (OR 5.5; 95%CI 1.16–26.41). We found no difference between the ECLS and non‐ECLS cohorts regarding cannula‐associated DVT rate (33% vs. 32%).

Conclusion

Post‐ECLS‐DVT is a common finding that occurs in half of all patients supported with ECLS. The incidence of cannula‐associated DVT was equal to CVC‐associated DVT in critically ill patients without ECLS. V‐V ECLS was an independent risk factor for post‐ECLS‐DVT.

Long-term 5-year outcome of the randomized IMPRESS in severe shock trial: percutaneous mechanical circulatory support vs. intra-aortic balloon pump in cardiogenic shock after acute myocardial infarction

AIMS

To assess differences in long-term outcome and functional status of patients with cardiogenic shock (CS) treated by percutaneous mechanical circulatory support (pMCS) and intra-aortic balloon pump (IABP).

METHODS AND RESULTS

Long-term follow-up of the multicentre, randomized IMPRESS in Severe Shock trial (NTR3450) was performed 5-year after initial randomization. Between 2012 and 2015, a total of 48 patients with severe CS from acute myocardial infarction (AMI) with ST-segment elevation undergoing immediate revascularization were randomized to pMCS by Impella CP (n = 24) or IABP (n = 24). For the 5-year assessment, all-cause mortality, functional status, and occurrence of major adverse cardiac and cerebrovascular event (MACCE) were assessed. MACCE consisted of death, myocardial re-infarction, repeat percutaneous coronary intervention, coronary artery bypass grafting, and stroke. Five-year mortality was 50% (n = 12/24) in pMCS patients and 63% (n = 15/24) in IABP patients (relative risk 0.87, 95% confidence interval 0.47-1.59, P = 0.65). MACCE occurred in 12/24 (50%) of the pMCS patients vs. 19/24 (79%) of the IABP patients (P = 0.07). All survivors except for one were in New York Heart Association Class I/II [pMCS n = 10 (91%) and IABP n = 7 (100%), P = 1.00] and none of the patients had residual angina. There were no differences in left ventricular ejection fraction between the groups (pMCS 52 ± 11% vs. IABP 48 ± 10%, P = 0.53).

CONCLUSIONS

In this explorative randomized trial of patients with severe CS after AMI, there was no difference in long-term 5-year mortality between pMCS and IABP-treated patients, supporting previously published short-term data and in accordance with other long-term CS trials.

Definition and incidence of hypotension in intensive care unit patients, an international survey of the European Society of Intensive Care Medicine

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.

Outcome and Predictors for Mortality in Patients with Cardiogenic Shock: A Dutch Nationwide Registry-Based Study of 75,407 Patients with Acute Coronary Syndrome Treated by PCI

It is important to gain more insight into the cardiogenic shock (CS) population, as currently, little is known on how to improve outcomes. Therefore, we assessed clinical outcome in acute coronary syndrome (ACS) patients treated by percutaneous coronary intervention (PCI) with and without CS at admission. Furthermore, the incidence of CS and predictors for mortality in CS patients were evaluated. The Netherlands Heart Registration (NHR) is a nationwide registry on all cardiac interventions. We used NHR data of ACS patients treated with PCI between 2015 and 2019. Among 75,407 ACS patients treated with PCI, 3028 patients (4.1%) were identified with CS, respectively 4.3%, 3.9%, 3.5%, and 4.3% per year. Factors associated with mortality in CS were age (HR 1.02, 95%CI 1.02–1.03), eGFR (HR 0.98, 95%CI 0.98–0.99), diabetes mellitus (DM) (HR 1.25, 95%CI 1.08–1.45), multivessel disease (HR 1.22, 95%CI 1.06–1.39), prior myocardial infarction (MI) (HR 1.24, 95%CI 1.06–1.45), and out-of-hospital cardiac arrest (OHCA) (HR 1.71, 95%CI 1.50–1.94). In conclusion, in this Dutch nationwide registry-based study of ACS patients treated by PCI, the incidence of CS was 4.1% over the 4-year study period. Predictors for mortality in CS were higher age, renal insufficiency, presence of DM, multivessel disease, prior MI, and OHCA.

Survival of patients with acute pulmonary embolism treated with venoarterial extracorporeal membrane oxygenation: A systematic review and meta-analysis

BACKGROUND

To examine whether venoarterial extracorporeal membrane oxygenation (VA-ECMO) improves survival of patients with acute pulmonary embolism (PE).

METHODS

Following the PRISMA guidelines, a systematic search was conducted up to August 2019 of the databases: PubMed/MEDLINE, EMBASE and Cochrane. All studies reporting the survival of adult patients with acute PE treated with VA-ECMO and including four patients or more were included. Exclusion criteria were: correspondences, reviews and studies in absence of a full text, written in other languages than English or Dutch, or dating before 1980. Short-term (hospital or 30-day) survival data were pooled and presented with relative risks (RR) and 95% confidence intervals (95% CI). Also, the following pre-defined factors were evaluated for their association with survival in VA-ECMO treated patients: age > 60 years, male sex, pre-ECMO cardiac arrest, surgical embolectomy, catheter directed therapy, systemic thrombolysis, and VA-ECMO as single therapy.

RESULTS

A total of 29 observational studies were included (N = 1947 patients: VA-ECMO N = 1138 and control N = 809). There was no difference in short-term survival between VA-ECMO treated patients and control patients (RR 0.91, 95% CI 0.71-1.16). In acute PE patients undergoing VA-ECMO, age > 60 years was associated with lower survival (RR 0.72, 95% CI 0.52-0.99), surgical embolectomy was associated with higher survival (RR 1.96, 95% CI 1.39-2.76) and pre-ECMO cardiac arrest showed a trend toward lower survival (RR 0.88, 95% CI 0.77-1.01). The other evaluated factors were not associated with a difference in survival.

CONCLUSIONS

At present, there is insufficient evidence that VA-ECMO treatment improves short-term survival of acute PE patients. Low quality evidence suggest that VA-ECMO patients aged ≤60 years or who received SE have higher survival rates. Considering the limited evidence derived from the present data, this study emphasizes the need for prospective studies.

PROTOCOL REGISTRATION

PROSPERO CRD42019120370.

Associations of Body Mass Index with Ventilation Management and Clinical Outcomes in Invasively Ventilated Patients with ARDS Related to COVID-19-Insights from the PRoVENT-COVID Study

We describe the practice of ventilation and mortality rates in invasively ventilated normal-weight (18.5 ≤ BMI ≤ 24.9 kg/m²), overweight (25.0 ≤ BMI ≤ 29.9 kg/m²), and obese (BMI > 30 kg/m²) COVID-19 ARDS patients in a national, multicenter observational study, performed at 22 intensive care units in the Netherlands. The primary outcome was a combination of ventilation variables and parameters over the first four calendar days of ventilation, including tidal volume, positive end–expiratory pressure (PEEP), respiratory system compliance, and driving pressure in normal–weight, overweight, and obese patients. Secondary outcomes included the use of adjunctive treatments for refractory hypoxaemia and mortality rates. Between 1 March 2020 and 1 June 2020, 1122 patients were included in the study: 244 (21.3%) normal-weight patients, 531 (47.3%) overweight patients, and 324 (28.8%) obese patients. Most patients received a tidal volume < 8 mL/kg PBW; only on the first day was the tidal volume higher in obese patients. PEEP and driving pressure were higher, and compliance of the respiratory system was lower in obese patients on all four days. Adjunctive therapies for refractory hypoxemia were used equally in the three BMI groups. Adjusted mortality rates were not different between BMI categories. The findings of this study suggest that lung-protective ventilation with a lower tidal volume and prone positioning is similarly feasible in normal-weight, overweight, and obese patients with ARDS related to COVID-19. A patient’s BMI should not be used in decisions to forgo or proceed with invasive ventilation.

Reduced Cardiac Index Reserve and Hypovolemia in Severe Falciparum Malaria

BACKGROUND

Impaired microvascular perfusion is central to the development of coma and lactic acidosis in severe falciparum malaria. Refractory hypotension is rare on admission but develops frequently in fatal cases. We assessed cardiac function and volume status in severe falciparum malaria and its prognostic significance.

METHODS

Patients with severe (N = 101) or acute uncomplicated falciparum malaria (N = 83) were recruited from 2 hospitals in India and Bangladesh, and healthy participants (N = 44) underwent echocardiography.

RESULTS

Patients with severe malaria had 38% shorter left ventricular (LV) filling times and 25% shorter LV ejection times than healthy participants because of tachycardia; however, stroke volume, LV internal diameter in diastole (LVIDd), and LV internal diameter in systole (LVIDs) indices were similar. A low endocardial fraction shortening (eFS) was present in 17% (9 of 52) of severe malaria patients. Adjusting for preload and afterload, eFS was similar in health and severe malaria. Fatal cases had smaller baseline LVIDd and LVIDs indices, more collapsible inferior vena cavae (IVC), and higher heart rates than survivors. The LVIDs and IVC collapsibility were independent predictors for mortality, together with base excess and Glasgow Coma Scale.

CONCLUSIONS

Patients with severe malaria have rapid ejection of a normal stroke volume. Fatal cases had features of relative hypovolemia and reduced cardiac index reserve.

The effects of tidal volume size and driving pressure levels on pulmonary complement activation: an observational study in critically ill patients

Background

Mechanical ventilation can induce or even worsen lung injury, at least in part via overdistension caused by too large volumes or too high pressures. The complement system has been suggested to play a causative role in ventilator-induced lung injury.

Aims and methods

This was a single-center prospective study investigating associations between pulmonary levels of complement activation products and two ventilator settings, tidal volume (V_T) and driving pressure (ΔP), in critically ill patients under invasive ventilation. A miniature bronchoalveolar lavage (BAL) was performed for determination of pulmonary levels of C5a, C3b/c, and C4b/c. The primary endpoint was the correlation between BAL fluid (BALF) levels of C5a and V_T and ΔP. Levels of complement activation products were also compared between patients with and without ARDS or with and without pneumonia.

Results

Seventy-two patients were included. Median time from start of invasive ventilation till BAL was 27 [19 to 34] hours. Median V_T and ΔP before BAL were 6.7 [IQR 6.1 to 7.6] ml/kg predicted bodyweight (PBW) and 15 [IQR 11 to 18] cm H₂O, respectively. BALF levels of C5a, C3b/c and C4b/c were neither different between patients with or without ARDS, nor between patients with or without pneumonia. BALF levels of C5a, and also C3b/c and C4b/c, did not correlate with V_T and ΔP. Median BALF levels of C5a, C3b/c, and C4b/c, and the effects of V_T and ΔP on those levels, were not different between patients with or without ARDS, and in patients with or without pneumonia.

Conclusion

In this cohort of critically ill patients under invasive ventilation, pulmonary levels of complement activation products were independent of the size of V_T and the level of ΔP. The associations were not different for patients with ARDS or with pneumonia. Pulmonary complement activation does not seem to play a major role in VILI, and not even in lung injury per se, in critically ill patients under invasive ventilation.

Pre-PCI versus immediate post-PCI Impella initiation in acute myocardial infarction complicated by cardiogenic shock

Background

In selected patients with an acute myocardial infarction (AMI) complicated by Cardiogenic shock (CS), mechanical circulatory support with Impella may be beneficial, although conclusive evidence is still lacking. Nevertheless, it has been suggested that Impella initiation prior to primary PCI might improve survival.

Objective

To investigate the effect pre-PCI versus immediate post-PCI Impella initiation on short term mortality.

Methods

A prospective, single center, observational study, was performed including all patients with STEMI complicated by CS, treated with primary PCI and Impella. Thirty day mortality was compared between patients with Impella initiation pre-PCI and immediately post-PCI.

Results

A total of 88 patients were included. In the pre-PCI group (n = 21), admission heart rate was lower (84 versus 94 bpm, p = 0.04) and no IABP was implanted before Impella initiation, versus 17.9% in post-PCI group (n = 67), p = 0.04. Total 30-day all-cause mortality was 58%, and was lower in pre-PCI group, 47.6% versus 61.2% in the post-PCI group, however not statistically significant (HR 0.7, 95% CI 0.3–1.3, p = 0.21). Thirty-day cardiac mortality was significantly lower in the pre-PCI group, 19% versus 44.7% in the post-PCI group (HR 0.3, 95% CI 0.09–0.96, p = 0.042).

Conclusion

Pre-PCI Impella initiation in AMICS patients was not associated with a statistically significant difference in 30-day all-cause mortality, compared to post-PCI Impella initiation.

Assessing Extravascular Lung Water in Critically Ill Patients Using Lung Ultrasound: A Systematic Review on Methodological Aspects in Diagnostic Accuracy Studies

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.

Vasopressors and Inotropes in Acute Myocardial Infarction Related Cardiogenic Shock: A Systematic Review and Meta-Analysis

Vasopressors and inotropes are routinely used in acute myocardial infarction (AMI) related cardiogenic shock (CS) to improve hemodynamics. We aimed to investigate the effect of routinely used vasopressor and inotropes on mortality in AMI related CS. A systematic search of MEDLINE, EMBASE and CENTRAL was performed up to 20 February 2019. Randomized and observational studies reporting mortality of AMI related CS patients were included. At least one group should have received the vasopressor/inotrope compared with a control group not exposed to the vasopressor/inotrope. Exclusion criteria were case reports, correspondence and studies including only post-cardiac surgery patients. In total, 19 studies (6 RCTs) were included, comprising 2478 CS patients. The overall quality of evidence was graded low. Treatment with adrenaline, noradrenaline, vasopressin, milrinone, levosimendan, dobutamine or dopamine was not associated with a difference in mortality between therapy and control group. We found a trend toward better outcome with levosimendan, compared with control (RR 0.69, 95% CI 0.47-1.00). In conclusion, we found insufficient evidence that routinely used vasopressors and inotropes are associated with reduced mortality in patients with AMI related CS. Considering the limited evidence, this study emphasizes the need for randomized trials with appropriate endpoints and methodology.

Mechanical circulatory support in cardiogenic shock from acute myocardial infarction: Impella CP/5.0 versus ECMO

Background:

Short-term mechanical circulatory support devices are increasingly used in cardiogenic shock after acute myocardial infarction. As no randomised evidence is available, the choice between high-output Impella or extra-corporeal membrane oxygenation (ECMO) is still a matter of debate. Real-life data are necessary to assess adverse outcomes and to help guide the treatment decision between the different devices. The purpose of this study was to compare characteristics and clinical outcomes of Impella CP/5.0 with ECMO support in patients with cardiogenic shock from myocardial infarction.

Methods:

A retrospective, two-centre study was performed on all cardiogenic shock from myocardial infarction patients with Impella CP/5.0 or ECMO support, from 2006 until 2018. The primary outcome was 30-day mortality. Potential baseline imbalance between the groups was adjusted using inverse probability treatment weighting, and survival analysis was performed with an adjusted log-rank test. Secondarily, the occurrence of device-related complications (limb ischaemia, access site-related bleeding, access site-related infection) was evaluated.

Results:

A total of 128 patients were included (Impella, N=90; ECMO, N=38). The 30-day mortality was similar for both groups (53% vs. 49%, P=0.30), also after adjustment for potential baseline imbalance between the groups (weighted log-rank P=0.16). Patients with Impella support had significantly fewer device-related complications than patients treated with ECMO (respectively, 17% vs. 40%, P<0.01).

Conclusions:

Patients treated with Impella CP/5.0 or ECMO for cardiogenic shock after myocardial infarction did not differ in 30-day mortality. More device-related complications occurred with ECMO compared to Impella support.

Pulmonary complement depositions in autopsy of critically ill patients have no relation with ARDS

Background

The complement system has frequently been suggested to play a role in the pathophysiology of acute respiratory distress syndrome (ARDS). The current study explored the association between pulmonary depositions of a complement activation product and the clinical diagnosis of ARDS.

Methods

Lung tissue material from autopsied critically ill patients who died whilst on invasively mechanical ventilation was collected and stained for complement C3d. The diagnosis of ARDS was by the Berlin Definition. Lung injury scores (LIS) and driving pressures were calculated, 48 and 24 h prior to death. A pathologist who remained blinded for the clinical data scored the extent of C3d depositions, using a C3d deposition score (a minimum and maximum score of 0 and 24), and of diffuse alveolar damage (DAD). The primary analysis focused on the association between the C3d deposition score and the clinical diagnosis of ARDS. Secondary analyses focused on associations between the C3d deposition score and the presence of diffuse alveolar damage (DAD) in histopathology, and LIS and driving pressures in the last 2 days before death.

Results

Of 36 patients of whom autopsy material was available, 12 were diagnosed as having had ARDS. In all patients, C3d depositions were found in various parts of the lungs, and to a different extent. Notably, C3d deposition scores were similar for patients with ARDS and those without ARDS (4.5 [3.3–6.8] vs. 5.0 [4.0–6.0]; not significant). C3d deposition scores were also independent from the presence or absence of DAD, and correlations between C3d scores and LIS and driving pressures prior to death were poor.

Conclusion

Pulmonary C3d depositions are found in the lungs of all deceased ICU patients, independent of the diagnosis of ARDS. The presence of complement C3d was not associated with the presence of DAD on histopathology and had a poor correlation with ventilation characteristics prior to death.

The diagnostic accuracy for ARDS of global versus regional lung ultrasound scores - a post hoc analysis of an observational study in invasively ventilated ICU patients

Background

Semi-quantification of lung aeration by ultrasound helps to assess presence and extent of pulmonary pathologies, including the acute respiratory distress syndrome (ARDS). It is uncertain which lung regions add most to the diagnostic accuracy for ARDS of the frequently used global lung ultrasound (LUS) score. We aimed to compare the diagnostic accuracy of the global versus those of regional LUS scores in invasively ventilated intensive care unit patients.

Methods

This was a post-hoc analysis of a single-center observational study in the mixed medical–surgical intensive care unit of a university-affiliated hospital in the Netherlands. Consecutive patients, aged ≥ 18 years, and are expected to receive invasive ventilation for > 24 h underwent a LUS examination within the first 2 days of ventilation. The Berlin Definition was used to diagnose ARDS, and to classify ARDS severity. From the 12-region LUS examinations, the global score (minimum 0 to maximum 36) and 3 regional scores (the ‘anterior,’ ‘lateral,’ and ‘posterior’ score, minimum 0 to maximum 12) were computed. The area under the receiver operating characteristic (AUROC) curve was calculated and the best cutoff for ARDS discrimination was determined for all scores.

Results

The study enrolled 152 patients; 35 patients had ARDS. The global score was higher in patients with ARDS compared to patients without ARDS (median 19 [15–23] vs. 5 [3–9]; P < 0.001). The posterior score was the main contributor to the global score, and was the only score that increased significantly with ARDS severity. However, the posterior score performed worse than the global score in diagnosing ARDS, and it had a positive predictive value of only 50 (41–59)% when using the optimal cutoff. The combined anterolateral score performed as good as the global score (AUROC of 0.91 [0.85–0.97] vs. 0.91 [0.86–0.95]).

Conclusions

While the posterior score increases with ARDS severity, its diagnostic accuracy for ARDS is hampered due to an unfavorable signal-to-noise ratio. An 8-region ‘anterolateral’ score performs as well as the global score and may prove useful to exclude ARDS in invasively ventilated ICU patients.

Real-life use of left ventricular circulatory support with Impella in cardiogenic shock after acute myocardial infarction: 12 years AMC experience

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.

Two Cases of Endocarditis After MitraClip Procedure Necessitating Surgical Mitral Valve Replacement

In the present report, we describe 2 cases of endocarditis after MitraClip (Abbott Vascular, Santa Clara, CA) procedures. In both patients, successful bailout surgical treatment was performed despite a high-risk constellation due to significant comorbidities. These cases highlight that surgical treatment may still be an option in patients initially declined for surgical therapy and that endocarditis after MitraClip procedure might be an underrecognized complication.

Correction to: External confirmation and exploration of the Kigali modification for diagnosing moderate or severe ARDS

In Table 1 of this article, the numerical data were correct but the graphic part was imprecise.

[Support of damaged heart with the Impella pump]

Temporary mechanical circulatory support is increasingly used, particularly in patients with cardiogenic shock or during high-risk percutaneous coronary interventions. In the last five years there have been numerous developments in this field. Experience has been gained from usage of temporary heart pumps, and new pumps have arrived on the market. Until recently, the intra-aortal balloon pump was the standard treatment for patients with cardiogenic shock; however, results from the latest research into the effectiveness of this pump have rendered it less popular. An alternative modality is the Impella system. Since 2012, usage of a heart pump in cardiogenic shock treatment is reimbursed by healthcare insurers in the Netherlands. Recently, the FDA approved the Impella system for said indication.

Extracorporeal life support during cardiac arrest and cardiogenic shock: a systematic review and meta-analysis

Purpose

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.

Methods

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 I² statistic.

Results

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).

Conclusions

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.

Electronic supplementary material

The online version of this article (doi:10.1007/s00134-016-4536-8) contains supplementary material, which is available to authorized users.

Helium ventilation for treatment of post-cardiac arrest syndrome: A safety and feasibility study

AIM

Besides supportive care, the only recommended treatment for comatose patients after cardiac arrest is target temperature management. Helium reduces ischaemic injury in animal models, and might ameliorate neurological injury in patients after cardiac arrest. As no studies exist on the use of helium in patients after cardiac arrest we investigated whether this is safe and feasible.

METHODS

The study was an open-label single arm intervention study in a mixed-bed academic intensive care unit. We included 25 patients admitted after circulatory arrest, with a presenting rhythm of ventricular fibrillation or pulseless tachycardia, return of spontaneous circulation within 30min and who were treated with hypothermia. Helium was administrated in a 1:1 mix with oxygen for 3h. A safety committee reviewed all ventilation problems, complications and causes of mortality.

RESULTS

Helium ventilation was started 4:59±0:52 (mean±SD)h after circulatory arrest. In one patient, helium ventilation was discontinued prematurely due to oxygenation problems. This was caused by pre-existing pulmonary oedema, and imposed limitations to PEEP and FiO2 by the study protocol, rather than the use of helium ventilation. Sixteen (64%) patients had a favourable neurological outcome.

CONCLUSIONS

We found that helium ventilation is feasible and can be used safely in patients treated with hypothermia after cardiac arrest. No adverse events related to the use of helium occurred during the three hours of administration.

Effect of extracorporeal CO2 removal on right ventricular and hemodynamic parameters in a patient with acute respiratory distress syndrome

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.

Low tidal volume ventilation ameliorates left ventricular dysfunction in mechanically ventilated rats following LPS-induced lung injury

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.

Impact of Positive End-Expiratory Pressure on Thermodilution-Derived Right Ventricular Parameters in Mechanically Ventilated Critically Ill Patients

OBJECTIVES

To examine the effect of positive end-expiratory pressure (PEEP) on right ventricular stroke volume variation (SVV), 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 cmH2O and from 10-to-15 cmH2O with 10-minute intervals, with similar decreases in PEEP, from 15-to-10 cmH2O and 10-to-5 cmH2O.

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 cmH2O PEEP (p = 0.01 and p = 0.001, respectively). Right ventricular SVV 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 SVV 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.

Plasma-derived human C1-esterase inhibitor does not prevent mechanical ventilation-induced pulmonary complement activation in a rat model of Streptococcus pneumoniae pneumonia

Mechanical ventilation has the potential to cause lung injury, and the role of complement activation herein is uncertain. We hypothesized that inhibition of the complement cascade by administration of plasma-derived human C1-esterase inhibitor (C1-INH) prevents ventilation-induced pulmonary complement activation, and as such attenuates lung inflammation and lung injury in a rat model of Streptococcus pneumoniae pneumonia. Forty hours after intratracheal challenge with S. pneumoniae causing pneumonia rats were subjected to ventilation with lower tidal volumes and positive end-expiratory pressure (PEEP) or high tidal volumes without PEEP, after an intravenous bolus of C1-INH (200 U/kg) or placebo (saline). After 4 h of ventilation blood, broncho-alveolar lavage fluid and lung tissue were collected. Non-ventilated rats with S. pneumoniae pneumonia served as controls. While ventilation with lower tidal volumes and PEEP slightly amplified pneumonia-induced complement activation in the lungs, ventilation with higher tidal volumes without PEEP augmented local complement activation more strongly. Systemic pre-treatment with C1-INH, however, failed to alter ventilation-induced complement activation with both ventilation strategies. In accordance, lung inflammation and lung injury were not affected by pre-treatment with C1-INH, neither in rats ventilated with lower tidal volumes and PEEP, nor rats ventilated with high tidal volumes without PEEP. Ventilation augments pulmonary complement activation in a rat model of S. pneumoniae pneumonia. Systemic administration of C1-INH, however, does not attenuate ventilation-induced complement activation, lung inflammation, and lung injury.

Pulse pressure variation does not reflect stroke volume variation in mechanically ventilated rats with lipopolysaccharide-induced pneumonia

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.

Conventional hemodynamic resuscitation may fail to optimize tissue perfusion: an observational study on the effects of dobutamine, enoximone, and norepinephrine in patients with acute myocardial infarction complicated by cardiogenic shock

AIM

To investigate the effects of inotropic agents on parameters of tissue perfusion in patients with cardiogenic shock.

METHODS AND RESULTS

Thirty patients with cardiogenic shock were included. Patients received dobutamine, enoximone, or norepinephrine. We performed hemodynamic measurements at baseline and after titration of the inotropic agent until cardiac index (CI) ≥ 2.5 L.min-1.m(-2) or mixed-venous oxygen saturation (SvO2) ≥ 70% (dobutamine or enoximone), and mean arterial pressure (MAP) ≥ 70 mmHg (norepinephrine). As parameters of tissue perfusion, we measured central-peripheral temperature gradient (delta-T) and sublingual perfused capillary density (PCD). All patients reached predefined therapeutic targets. The inotropes did not significantly change delta-T. Dobutamine did not change PCD. Enoximone increased PCD (9.1 [8.9-10.2] vs. 11.4 [8.4-13.9] mm.mm(-2); p<0.05), and norepinephrine tended to decrease PCD (9.8 [8.5-11.9] vs. 8.8 [8.2-9.6] mm.mm-2, p = 0.08). Fifteen patients (50%) died within 30 days after admission. Patients who had low final PCD (≤ 10.3 mm.mm-2; 64%) were more likely to die than patients who had preserved PCD (>10.3 mm.mm(-2); mortality 72% vs. 17%, p = 0.003).

CONCLUSION

This study demonstrates the effects of commonly used inotropic agents on parameters of tissue perfusion in patients with cardiogenic shock. Despite hemodynamic optimization, tissue perfusion was not sufficiently restored in most patients. In these patients, mortality was high. Interventions directed at improving microcirculation may eventually help bridging the gap between improved hemodynamics and dismal patient outcome in cardiogenic shock.

Mechanical circulatory support with the Impella 5.0 device for postcardiotomy cardiogenic shock: a three-center experience

AIM

Postcardiotomy cardiogenic shock (PCCS) is associated with high mortality rates, despite full conventional treatment. Although the results of treatment with surgically implantable ventricular assist devices have been encouraging, the invasiveness of this treatment limits its applicability. Several less invasive devices have been developed, including the Impella system. The objective of this study was to describe our three-center experience with the Impella 5.0 device in the setting of PCCS.

METHODS

From January 2004 through December 2010, a total of 46 patients were diagnosed with treatment-refractory PCCS and treated with the Impella 5.0 percutaneous left ventricular assist device at three european heart centers. Baseline and follow-up characteristics were collected retrospectively and entered into a dedicated database.

RESULTS

Within the study cohort of 46 patients, mean logistic and additive EuroSCORES were 24 ± 19 and 10 ± 4. The majority of patients underwent coronary artery bypass grafting (48%) or combined surgery (33%). Half of all patients had been treated with an intra-aortic balloon pump before 5.0-implantation, 1 patient had been treated with an Impella 2.5 device. All patients were on mechanical ventilation and intravenous inotropes. The Kaplan-Meier estimate of overall 30-day survival was 39.5%.

CONCLUSION

Thirty-day survival rates for patients with PCCS, refractory to aggressive conventional treatment and treated with the Impella 5.0 device, are comparable to those reported in studies evaluating surgically implantable VADs, whereas the Impella system is much less invasive. Therefore, mechanical circulatory support with the Impella 5.0 device is a suitable treatment modality for patients with severe PCCS.

Haemodynamic monitoring of morbidly obese intensive care unit patients

Because of technical and practical difficulties in relation to increased body size, haemodynamic monitoring of morbidly obese critically ill patients (i.e. body mass index &#8805;40 kg÷m2) may be challenging. Obese and non-obese patients are not so different with respect to haemodynamic monitoring and goals. The critical care physician, however, should be aware of the basic principles of the monitoring tools used. The theoretical assumptions and calculations of these tools could be invalid because of the high body weight and fat distribution. Although the method of assessing haemodynamic data may be more complex in morbidly obese patients, its interpretation should not be different from that in non-obese patients. Indeed, when indexed for body surface area or (predicted) lean body mass, reliable haemodynamic data are comparable etween obese and non-obese individuals.

IgM antibodies against apoptotic cells and phosphorylcholine in patients with acute myocardial infarction in relation to infarct size and inflammatory response

BACKGROUND

Natural IgM antibodies, and anti-phosphorylcholine IgM (anti-PC IgM) in particular, may modulate the pathogenesis of acute myocardial infarction (AMI).

OBJECTIVES

An exploratory study was conducted to evaluate the hypothesis that circulating anti-PC IgM and IgM binding to damaged cells increases the infarct size and post-infarct inflammatory response in patients with AMI.

MATERIAL AND METHODS

Plasma IgM binding to apoptotic cells (anti-apop IgM) and anti-PC IgM levels were compared in plasma samples from 50 patients with AMI and 46 healthy controls after correction for hemodilution. The cumulative release of cardiac markers LDH (lactate dehydrogenase), CK or CK-MB in human myocardium at 48 hours was used as an indication of infarct size. The circulating levels of mediators such as activated complement, C-reactive protein (CRP), interleukin-6 (IL6), interleukin-8 (IL8) and secretory phospholipase A2 (sPLA2) were used to assess the post-infarct inflammatory response. Patients with low (< median) and high (> median) levels of anti-apop IgM or anti-PC IgM were compared regarding infarct size and post-infarct inflammatory response. An electrocardiographical scoring system (Selvester score) was used to asses myocardial infarct size in patients with a first AMI (n = 24).

RESULTS

AMI patients demonstrated lower levels of anti-PC IgM on admission (p < 0.01) and at 48 hours (p < 0.001) when compared to the healthy controls, whereas anti-apop IgM levels were comparable to control levels. In patients with a first infarct, patients with levels of anti-PC IgM above the median demonstrated larger electrocardiographic infarct sizes (p = 0.04) and a more pronounced response of the acute phase protein sPLA2 (p = 0.06), with a similar post-infarct course of LDH, CK and CK-MB.

CONCLUSIONS

These findings suggest that anti-PC IgM plasma levels may participatie in amplifying the inflammatory response of the ischemic heart and contribute to infarct size. However, the levels of anti-PC IgM in patients with AMI in this study do not show a significant effect on cardiac markers LDH, CK and CK-MB. Hence, conclusive evidence is not provided by this limited cohort.

Left-sided native valve Staphylococcus aureus endocarditis

Despite improved diagnostic tools and expanded treatment options, left-sided native valve endocarditis caused by Staphylococcus aureus infection remains a serious and destructive disease. The high morbidity and mortality, however, can be reduced by early recognition, correct diagnosis, and appropriate treatment. In the following article, we discuss the clinical presentation, diagnostic workup and treatment of infective endocarditis, thereby reviewing the current guidelines. Blood cultures and echocardiography are the cornerstones of diagnosis in identifying infective endocarditis but are no substitute for clinical judgement. The modified Duke criteria may facilitate the diagnostic process, but clinical evaluation remains crucial.

[The Impella system for mechanical support and myocardial recovery]

Mechanical circulatory support has become an increasingly important therapeutic option in the field of cardiology, both with regard to treatment of patients in cardiogenic shock and protection against haemodynamic instability during high-risk percutaneous coronary intervention (PCI). The intra-aortic balloon pump (IABP) is the current standard treatment for mechanical circulatory support. However, its efficacy seems limited, both in acute and elective settings. The Impella system is a new technique which may be a suitable alternative to IABP treatment. The Impella is a small micro-axial, catheter-mounted cardiac pump, which is inserted through the femoral artery. Safety and efficacy of Impella treatment have been demonstrated during elective high-risk PCI. In the setting of cardiogenic shock, mechanical support with the Impella may lead to partial recovery of left ventricular function, especially when Impella treatment is applied according to a carefully designed pre-specified protocol..

Intra-operative assessment of human pulmonary alveoli in vivo using Sidestream Dark Field imaging: a feasibility study

BACKGROUND

In vivo videomicroscopy has been used for years to visualize subpleural alveoli in animal studies. This has led to a better understanding of alveolar physiology. We tested the hypothesis whether a novel handheld videomicroscope could be used for intraoperative detection of alveoli in surgical patients during mechanical ventilation.

MATERIAL/METHODS

Using Sidestream Dark Field imaging, we observed 6 patients (3 adults and 3 children) who underwent elective cardiac surgery. In each patient, the tip of the microscope was placed on the visceral pleural surface of the left upper pulmonary lobe after weaning from cardiopulmonary bypass. The acquired images were converted into digital signals and captured on a computer.

RESULTS

Although cardiac motion artifacts were present, visceral pleural microvascular blood flow could be observed in adults and infants. In infants, sub-pleural cavities (alveoli) were observed. These alveoli were remarkably similar in dimension and structure to those identified previously as true alveoli in animal studies. Quantification of these alveoli demonstrated that mean alveolar diameter, perimeter and area increased with age among the investigated infants (all parameters p<0.001).

CONCLUSIONS

High-quality images of visceral pleural microvessels as well as subpleural cavities, reflecting superficial alveoli, could be obtained in infants. These findings create the opportunity to begin human intervention studies, which should investigate alveolar dynamics during mechanical ventilation in cardio-thoracic surgery in more detail.

Usefulness of intra-aortic balloon pump counterpulsation in patients with cardiogenic shock from acute myocardial infarction

Although intra-aortic balloon pump (IABP) counterpulsation is increasingly being used for the treatment of patients with cardiogenic shock from acute myocardial infarction, data on the long-term outcomes are lacking. The aim of the present study was to evaluate the 30-day and long-term mortality and to identify predictors for 30-day and long-term all-cause mortality of patients with acute myocardial infarction complicated by cardiogenic shock who were treated with IABP. From January 1990 to June 2004, 300 consecutive patients treated with IABP were included. The mean age of the study population was 61 +/- 11 years, and 79% of the patients were men. The survival rate until IABP removal after successful hemodynamic stabilization was 70% (n = 211). The overall cumulative 30-day survival rate was 58%. The 30-day mortality rate decreased over time from 52% in 1990 to 1994 to 36% in 2000 to 2004 (p for trend <0.05). Follow-up ranged from 0 to 15 years. In patients who survived until IABP removal, the cumulative 1-, 5-, and 10-year survival rate was 69%, 58%, and 36%, respectively. The adjusted predictors of long-term mortality were arrhythmias during the intensive cardiac care unit stay (hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.2 to 2.9) and renal failure during the intensive cardiac care unit stay (HR 2.5, 95% CI 1.3 to 5.1). After adjustment, treatment with primary percutaneous coronary intervention (HR 0.5, 95% CI 0.3 to 0.9) and coronary artery bypass grafting (HR 0.4, 95% CI 0.2 to 0.8) were associated with lower long-term mortality. In conclusion, in patients with acute myocardial infarction complicated by cardiogenic shock treated with IABP, the 30-day survival improved with time and an encouraging number of patients survived in the long term.

Dose-dependent benefit of nitroglycerin on microcirculation of patients with severe heart failure

INTRODUCTION

Microcirculatory abnormalities are frequently observed in patients with severe heart failure and correlate to worse outcomes. We tested the hypothesis that nitroglycerin dose-dependently improves perfusion in severe heart failure and that this could be monitored by measuring central-peripheral temperature gradient and with Sidestream Dark Field imaging of the sublingual mucosa.

METHODS

A dose-response study was performed in 17 patients with cardiogenic shock (n = 9) or end-stage chronic heart failure (n = 8) admitted to Erasmus University Medical Center. We did hemodynamic measurements at baseline and during increasing infusion rates of nitroglycerin (up to a maximum dose of 133 microg min(-1)). As parameters of tissue perfusion, we measured central-peripheral temperature gradient (delta-T) and sublingual perfused capillary density (PCD).

RESULTS

Nitroglycerin dose-dependently decreased mean arterial pressure (p < 0.001) and cardiac filling pressures (both central venous pressure (CVP) and pulmonary capillary wedge pressure: p < 0.001). It increased cardiac index (p = 0.01). Nitroglycerin decreased delta-T (p < 0.001) and increased sublingual PCD (p < 0.001). Significant changes in delta-T and PCD occurred earlier, i.e., at a lower doses of NTG, than changes in global hemodynamics. Macrohemodynamic and microcirculatory responses to nitroglycerin infusion were consistent in patients with either cardiogenic shock or end-stage chronic heart failure. Changes in microcirculatory parameters occurred independently of changes in cardiac index.

CONCLUSIONS

Nitroglycerin dose-dependently increases tissue perfusion in patients with severe heart failure, as observed by a decrease in central-peripheral temperature gradient and an increase in sublingual perfused capillary density.