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Chronic obstructive pulmonary disease (COPD) exacerbation induces hypercapnic respiratory acidosis. Extracorporeal carbon dioxide removal (ECCO2R) aims to eliminate blood carbon dioxide (CO2) in order to reduce adverse effects from hypercapnia and the related acidosis. Hypercapnia has deleterious extra-pulmonary consequences in increasing intracranial pressure and inducing and/or worsening right heart failure. During COPD exacerbation, the use of ECCO2R may improve the efficacy of non-invasive ventilation (NIV) in terms of CO2removal, decrease respiratory rate and reduce dynamic hyperinflation and intrinsic positive end expiratory pressure, which all contribute to increasing dead space. Moreover, ECCO2R may prevent NIV failure while facilitating the weaning of intubated patients from mechanical ventilation. In this review of the literature, the authors will present the current knowledge on the pathophysiology related to COPD, the principles of the ECCO2R technique and its role in acute and severe decompensation of COPD. However, despite technical advances, there are only case series in the literature and few prospective studies to clearly establish the role of ECCO2R in acute and severe COPD decompensation.

L’arrêt cardiaque (AC) est une cause importante de décès et un problème de santé publique. La réanimation cardiopulmonaire (RCP) conventionnelle est à ce jour la seule technique de réanimation efficace capable d’améliorer le pronostic des patients. L’ECMO est une technique lourde et relativement coûteuse qui nécessite une expertise. Elle ne peut donc pas être développée dans tous les centres et doit être réservée aux centres à haut volume d’implantation. Cette technique combinée à la RCP est appelée réanimation cardiopulmonaire extracorporelle (extracorporeal cardiopulmonary resuscitation[ECPR]). Elle permet une stabilisation hémodynamique et respiratoire des patients présentant un AC réfractaire aux techniques de RCP conventionnelles et permet, en maintenant une perfusion d’organe, de procéder au traitement de la cause de l’AC. Cependant, l’état actuel des connaissances ne permet pas de recommander l’utilisation de l’ECPR de routine chez tous les patients présentant un AC réfractaire. Il est donc primordial de sélectionner adéquatement les patients pouvant bénéficier de cette technique. C’est certainement en minimisant la durée du no-flow, en prodiguant une RCP de haute qualité, en réduisant la durée du low-flowet en accélérant l’accès à l’ECPR que la survie dans l’AC réfractaire pourrait être améliorée. L’objectif principal de ce type de prise en charge, à moyen et long terme, est de permettre aux patients réanimés de survivre avec un état neurologique acceptable.

La perfusion tissulaire d’un organe est à la fois tributaire de la circulation centrale et de la microcirculation. Bien que cette dernière entité soit la composante « vitale » du système cardiovasculaire, elle a longtemps été négligée en comparaison à l’étude approfondie de la macrocirculation. Néanmoins, s’il y a une discipline médicale qui a rendu ses lettres de noblesse à la physiologie de la circulation sanguine capillaire, c’est bien la réanimation. En effet, en traitant le patient en état de choc, le réanimateur a été confronté à des maladies et des syndromes où les dysfonctionnements majeurs de perfusion d’organes n’étaient pas toujours expliqués par les déterminants de la circulation centrale habituellement recueillis en réanimation. En effet, récemment, les connaissances physiopathologiques et les techniques de monitorage de la circulation capillaire sont devenues incontournables pour traiter les patients de réanimation. Le monitorage du comportement microcirculatoire permet de nos jours d’identifier puis de traiter les phénomènes fondamentaux à l’origine du découplage macro-microcirculatoires. À cet égard, la présente revue expose quelques exemples d’altérations de la perfusion tissulaire observés en réanimation, ou l’ensemble artères-artérioles et vaisseaux situés plus en aval ont perdu toute synchronie physiologique à même de leur permettre une perfusion optimale des organes vitaux.

Extracorporeal life support (ECLS) is increasingly used worldwide in patients with life-threatening hemodynamic and / or respiratory conditions. The femoral veno-arterial cannulation, whether percutaneous or surgical, is the simplest and quickest method, yet a number of vascular complications may occur. We present 2 cases in which, despite a well-placed reperfusion cannula in the superior femoral artery, apparent limb ischemia of the cannulated limb developed rapidly after ECLS implantation and was suspected to be due to arterial vasospasm. Both cases were successfully managed with the empiric injection of a vasodilator cocktail of nitroglycerin, verapamil and lidocain directly in the reperfusion cannula.

Extracorporeal life support (ECLS) is increasingly used worldwide in patients with life-threatening hemodynamic or respiratory conditions. The femoral venoarterial cannulation, whether percutaneous or surgical, is the simplest and quickest method; however, a number of vascular complications may occur. We present two cases in which, despite a well-placed reperfusion cannula in the superior femoral artery, apparent limb ischemia of the cannulated limb developed rapidly after ECLS implantation and was suspected to be caused by arterial vasospasm. Both cases were successfully managed with the injection of a vasodilator cocktail of verapamil, nitroglycerin, and lidocaine directly in the reperfusion cannula.

The positive predictive value of pulse pressure variations (PP) to discriminate patients who should respond to volume expansion (VE) may be altered in mechanically ventilated patients. Our goal was to determine whether intra-abdominal pressure (IAP) measurements could discriminate patients with true-positive PP values versus patients with false-positive PP values.

Pulse pressure variations (PPVs) and stroke volume variations (SVVs) are dynamic indices for predicting fluid responsiveness in intensive care unit patients. These hemodynamic markers underscore Frank-Starling law by which volume expansion increases cardiac output (CO). The aim of the present study was to evaluate the impact of the administration of catecholamines on PPV, SVV, and inferior vena cava flow (IVCF).

Medical therapeutic knowledge advances by continual action and reaction between retrospective and prospective evaluation on the one hand and clinical real-life observation and assessment on the other. In this regard, our goal is to articulate and demystify certain myths and misconceptions that impede the optimal management of patients with circulatory failure related to acute cardiac diseases. More specifically, we outline 5 statements that represent misconceptions about cardiogenic shock management that we have frequently faced throughout years of caring for critically ill patients. Moreover, for each statement, we suggest concise, corrective responses.

Sepsis-induced cardiomyopathy (SIC), which is a common morbid condition, occurs in patients with severe sepsis and septic shock. The clinical characterization of SIC has been largely concept-driven. Heart function has traditionally been evaluated according to two basic conceptual models: a hydraulic pump system, whereby the output from the heart is entirely dependent on its input, or a hemodynamic pump, whereby the cardiac output is a function of preload, global ventricular performance, and afterload. Minimal attention has been given to the intrinsic contractile function of the heart or to the interaction between the peripheral circulation and the intrinsic myocardial function in sepsis. Currently, SIC is assumed to be the result of the interaction of microorganisms that activate the physiopathological pathways and cellular signaling mechanisms that lead to intrinsic myocardial dysfunction. However, the animal models used to study SIC exhibit multiple limitations. This review addresses the conceptual background, historical perspectives, physiologic mechanisms, current evidence, and limitations of SIC characterization. It also highlights potential future directions for the hemodynamic assessment of the intrinsic contractile function of the heart to overcome current methodological limitations. Finally, the present review recommends the exploration of additional potential mechanisms underlying SIC.

Respiratory change in pre-ejection period (PEP) has been described as a potential parameter for monitoring cardiac preload dependency in critically ill patients. This study was designed to describe the relationship between PEP and pulse pressure variation (PPV) in pigs submitted to severe hemorrhagic shock.

Definition of the hemodynamic response to volume expansion (VE) could be useful in shocked critically ill patients in absence of cardiac index (CI) measurements. The aim of this study is to evaluate whether central venous oxygen saturation variations (ScvO2) after VE could be an alternative to classify responders (R) and nonresponders (NR) to volume therapy.

To evaluate the recent literature on the utility of the pulse oximetry plethysmographic curve to assess macrocirculation and microcirculation monitoring in intensive care patients.

To provide understanding of influence of cardiopulmonary bypass (CPB) on cerebral blood flow (CBF), we investigated the effect of CPB on patients' cerebral haemodynamic parameters. Twenty-three patients were prospectively enrolled. CBF was estimated by transcranial Doppler (TCD) to measure blood velocity in the middle cerebral artery (MVMCA), preoperatively T(0) and at four postoperative times (T(1), T(2), T(3), T(4)). At times T(2), T(3) and T(4), MVMCA remained at higher levels than T(0) (P < 0.05). In the multivariate analysis PaCO(2) was independently associated to MVMCA at times T(1) and T(2) (P = 0.03, P = 0.01, respectively) and temperature was independently associated with MVMCA at time T(1) (P = 0.02). Thus, the present study showed an increase in CBF after CPB, that was correlated with raised temperature but not with decrease in haematocrit.

Validation of new positron emission tomography (PET) tracers or magnetic (MR) imaging contrast agents is based on isolated rodent heart preparations. The use of larger animals could provide a more direct validation using the devices used for humans.

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Beta-blockers, previously considered contraindicated in heart failure are today amongst the most important drugs in heart failure. They improve survival and retard the need for cardiac transplantation. Since most clinical trials demonstrating the benefits of beta-blockers have been done in patients with mild to moderate heart failure, the use of these agents in patients with advanced heart failure remains contraindicated. In this brief review, the author theorizes that due to their immunomodulatory effects, beta-blockers may also play a helpful role in patients presenting cardiogenic shock related to septic shock. However, intensivists should keep in mind that no clinical data are available so far on the role of beta-blockers in septic cardiac shock. Thereby, because the use of beta-blockers in this setting is not established, nor recommended, it should only be applied under controlled trial conditions.

Blood sampling for venous-arterial CO2to arterial-venous O2content difference ratio starts to be widely used as a hemodynamic monitoring tool, despite that this calculation remains cumbersome. We propose using indirect calorimetry and respiratory quotient for this purpose, with the same physiological concept.

The pre-ejection period (PEP) has been described as a potential parameter for monitoring cardiac preload in deeply sedated mechanically ventilated patients. Other authors have recently suggested that PEP is not sensitive to the changes in intravascular volume status in mechanically ventilated pigs which underwent acute hemorrhage. The present comment is an analysis of this recent animal investigation.

According to the concept of Guyton, cardiac output is largely controlled by venous return, which is determined by the difference between mean systemic venous pressure and right atrial pressure. In the analysis of the venous return curve, other authors have suggested that right atrial pressure is the dependent variable and venous return is the independent variable (right atrial pressure decreased because cardiac output increased). The present report analyzes this historical debate, which has already lasted > 50 years.

Le monitorage des gaz respiratoires par calorimétrie indirecte est accessible chez le patient intubé en réanimation. Il peut être utilisé en situation stable afin d’évaluer le métabolisme de base. Utilisant le même module, la mesure de la consommation d’oxygène (VO2) pourrait être monitorée dans les états de choc pour une approche hémodynamique [1]. Nous avons voulu savoir si le matériel disponible en clinique pouvait être validé chez le gros animal.

A new system has been developed to assess global end-diastolic volume (GEDV), a volumetric marker of cardiac preload, and extravascular lung water (EVLW) from a transpulmonary thermodilution curve. Our goal was to compare this new system with the system currently in clinical use.

The pre-ejection period (PEP) has been described as a potential parameter for monitoring cardiac preload in deeply sedated mechanically ventilated patients. Other authors have recently suggested that PEP is not sensitive to the changes in intravascular volume status in mechanically ventilated pigs which underwent acute hemorrhage. The present comment is an analysis of this recent animal investigation.