Outcomes of patients admitted to intensive care units for acute manifestation of small-vessel vasculitis: a multicenter, retrospective study.

BACKGROUND: The outcomes of patients admitted to the intensive care unit (ICU) for acute manifestation of small-vessel vasculitis are poorly reported. The aim of the present study was to determine the mortality rate and prognostic factors of patients admitted to the ICU for acute small-vessel vasculitis. METHODS: This retrospective, multicenter study was conducted from January 2001 to December 2014 in 20 ICUs in France. Patients were identified from computerized registers of each hospital using the International Classification of Diseases, Ninth Revision (ICD-9). Inclusion criteria were (1) known or highly suspected granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, microscopic polyangiitis (respectively, ICD-9 codes M31.3, M30.1, and M31.7), or anti-glomerular basement membrane antibody disease (ICD-9 codes N08.5X-005 or M31.0+); (2) admission to the ICU for the management of an acute manifestation of vasculitis; and (3) administration of a cyclophosphamide pulse in the ICU or within 48 h before admission to the ICU. The primary endpoint was assessment of mortality rate 90 days after admission to the ICU. RESULTS: Eighty-two patients at 20 centers were included, 94% of whom had a recent (<6 months) diagnosis of small-vessel vasculitis. Forty-four patients (54%) had granulomatosis with polyangiitis. The main reasons for admission were respiratory failure (34%) and pulmonary-renal syndrome (33%). Mechanical ventilation was required in 51% of patients, catecholamines in 31%, and renal replacement therapy in 71%. Overall mortality at 90 days was 18% and the mortality in ICU was 16 %. The main causes of death in the ICU were disease flare in 69% and infection in 31%. In univariable analysis, relevant factors associated with death in nonsurvivors compared with survivors were Simplified Acute Physiology Score II (median [interquartile range] 51 [38-82] vs. 36 [27-42], p = 0.005), age (67 years [62-74] vs. 58 years [40-68], p < 0.003), Sequential Organ Failure Assessment score on the day of cyclophosphamide administration (11 [6-12] vs. 6 [3-7], p = 0.0004), and delayed administration of cyclophosphamide (5 days [3-14] vs. 2 days [1-5], p = 0.0053). CONCLUSIONS: Patients admitted to the ICU for management of acute small-vessel vasculitis benefit from early, aggressive intensive care treatment, associated with an 18% death rate at 90 days.

Hemodynamic consequences of severe lactic acidosis in shock states: from bench to bedside.

Lactic acidosis is a very common biological issue for shock patients. Experimental data clearly demonstrate that metabolic acidosis, including lactic acidosis, participates in the reduction of cardiac contractility and in the vascular hyporesponsiveness to vasopressors through various mechanisms. However, the contributions of each mechanism responsible for these deleterious effects have not been fully determined and their respective consequences on organ failure are still poorly defined, particularly in humans. Despite some convincing experimental data, no clinical trial has established the level at which pH becomes deleterious for hemodynamics. Consequently, the essential treatment for lactic acidosis in shock patients is to correct the cause. It is unknown, however, whether symptomatic pH correction is beneficial in shock patients. The latest Surviving Sepsis Campaign guidelines recommend against the use of buffer therapy with pH ≥7.15 and issue no recommendation for pH levels <7.15. Furthermore, based on strong experimental and clinical evidence, sodium bicarbonate infusion alone is not recommended for restoring pH. Indeed, bicarbonate induces carbon dioxide generation and hypocalcemia, both cardiovascular depressant factors. This review addresses the principal hemodynamic consequences of shock-associated lactic acidosis. Despite the lack of formal evidence, this review also highlights the various adapted supportive therapy options that could be putatively added to causal treatment in attempting to reverse the hemodynamic consequences of shock-associated lactic acidosis.

Efficient extra- and intracellular alkalinization improves cardiovascular functions in severe lactic acidosis induced by hemorrhagic shock.

BACKGROUND: Lactic acidosis is associated with cardiovascular failure. Buffering with sodium bicarbonate is proposed in severe lactic acidosis. Bicarbonate induces carbon dioxide generation and hypocalcemia, both cardiovascular depressant factors. The authors thus investigated the cardiovascular and metabolic effects of an adapted sodium bicarbonate therapy, including prevention of carbon dioxide increase with hyperventilation and ionized calcium decrease with calcium administration. METHODS: Lactic acidosis was induced by hemorrhagic shock. Twenty animals were randomized into five groups: (1) standard resuscitation with blood retransfusion and norepinephrine (2) adapted sodium bicarbonate therapy (3) nonadapted sodium bicarbonate therapy (4) standard resuscitation plus calcium administration (5) hyperventilation. Evaluation was focused in vivo on extracellular pH, on intracellular pH estimated by P nuclear magnetic resonance and on myocardial contractility by conductance catheter. Aortic rings and mesenteric arteries were isolated and mounted in a myograph, after which arterial contractility was measured. RESULTS: All animals in the hyperventilation group died prematurely and were not included in the statistical analysis. When compared with sham rats, shock induced extracellular (median, 7.13; interquartile range, [0.10] vs. 7.30 [0.01]; P = 0.0007) and intracellular acidosis (7.26 [0.18] vs. 7.05 [0.13]; P = 0.0001), hyperlactatemia (7.30 [0.01] vs. 7.13 [0.10]; P = 0.0008), depressed myocardial elastance (2.87 [1.31] vs. 0.5 [0.53] mmHg/µl; P = 0.0001), and vascular hyporesponsiveness to vasoconstrictors. Compared with nonadapted therapy, adapted bicarbonate therapy normalized extracellular pH (7.03 [0.12] vs. 7.36 [0.04]; P < 0.05), increased intracellular pH to supraphysiological values, improved myocardial elastance (1.68 [0.41] vs. 0.72 [0.44] mmHg/µl; P < 0.05), and improved aortic and mesenteric vasoreactivity. CONCLUSIONS: A therapeutic strategy based on alkalinization with sodium bicarbonate along with hyperventilation and calcium administration increases pH and improves cardiovascular function.

Comparison of equipressor doses of norepinephrine, epinephrine, and phenylephrine on septic myocardial dysfunction.

BACKGROUND: Myocardial depression is a frequent event during septic shock and may mimic a cardiogenic shock state with decreased cardiac output. Nevertheless, data are scarce regarding the myocardial effects of vasopressors used to treat hypotension. In this study, the authors compared the effects of three commonly used vasopressors acting on different adrenergic receptors on myocardial function in a rodent model of septic shock, as explored with conductance catheter and positron emission tomography. METHODS: Septic shock was induced in rats by peritonitis. Eighteen hours after septic insult, vasopressors were titrated to increase mean arterial pressure by 20% compared with baseline values. RESULTS: We observed that peritonitis was associated with arterial hypotension and systolodiastolic dysfunction. Norepinephrine and epinephrine improved mean arterial pressure, cardiac output, and preload recruitable stroke work, a load-independent measure of systolic function, as well as diastolic function and ventriculoarterial coupling. Heart rate, myocardial oxygen consumption, and arrhythmia incidence were furthermore increased in the epinephrine group. Conversely, phenylephrine, a peripheral α-agonist, exhibited deleterious effects on systolodiastolic function and ventriculoarterial coupling. Conductance catheter and positron emission tomography yielded identical results with regard to myocardial function evolution under vasopressor treatment. CONCLUSIONS: Phenylephrine, a drug without ß-1 effects, was associated with decreased ventricular performance and ventriculoarterial uncoupling, whereas epinephrine and norepinephrine improved global hemodynamics and myocardial function in severely hypokinetic and hypotensive experimental septic shock. Nevertheless, epinephrine was associated with increased myocardial oxygen consumption. Thus, norepinephrine appears to be a more reliable and safer strategy as a first-line therapy in this particular setting.

New conclusive data on human myocardial dysfunction induced by acidosis.

Acidosis is one of the major consequences of hemodynamic instability in shock state patients directly associated with multiple organ failure evolution and death. Most studies on the hemodynamic consequences of acidosis have been experimental, nonhuman studies with severe acidosis, and thus far from the most common clinical situations. Schotola and colleagues offer a new approach to human failing myocardium where the authors highlight, ex vivo, the deleterious hemodynamic consequences of mild acidosis. Their work strengthens the current view of the urgent need to discover new efficient and nondeleterious therapy for the treatment of acidosis.

Critical Illness-Related Corticosteroid Insufficiency in Cardiogenic Shock Patients: Prevalence and Prognostic Role.

BACKGROUND: Cardiogenic shock shares with septic shock common hemodynamic features, inflammatory patterns, and most likely similar complications such as critical illness-related corticosteroid insufficiency. The aim of this study was to evaluate the prevalence of critical illness-related corticosteroid insufficiency in cardiogenic shock patients and to secondarily assess its prognostic value on 90-day mortality. METHODS: A single-center prospective observational study conducted over a 3-year period and including all patients with cardiogenic shock. Main exclusion criteria were patients with prior cardiac arrest, sepsis, ongoing corticosteroid therapy, and etomidate administration. A short corticotropin test was performed in the first 24 h following admission. Serum cortisol levels were measured before (T0) and 60 min (T60) after administration of 250 µg of cosyntropin. Critical illness-related corticosteroid insufficiency was defined according to the 2017 consensus definition (basal total cortisol<10 µg·dL or a delta cortisol T60-T0<9 µg·dL) as well as the thresholds published in 2016 in cardiogenic shock patients associated with worst prognosis (basal total cortisol>29 µg·dL and delta cortisol T60-T0<17 µg·dL). RESULTS: Seventy-nine consecutive patients hospitalized in intensive care for cardiogenic shock met the inclusion criteria. Overall mortality was 43% at day 90. Forty-two percent had critical illness-related corticosteroid insufficiency using the 2017 consensus definition and 32% using the 2016 cardiogenic shock thresholds. Presence of critical illness-related corticosteroid insufficiency was not an independent factor associated with 90-day mortality irrespective of the thresholds used. CONCLUSION: Critical illness-related corticosteroid insufficiency is a frequent occurrence in medical cardiogenic shock. However, in this study, such insufficiency was not associated with prognosis.

Moderate Hypothermia Improves Cardiac and Vascular Function in a Pig Model of Ischemic Cardiogenic Shock Treated With Veno-Arterial ECMO.

Cardiogenic shock (CS) patients treated with extracorporeal membrane oxygenation (ECMO) have severe cardiac failure, associated with ischemia-reperfusion. The use of moderate hypothermia during ischemia-reperfusion syndrome is supported by experimental data. We therefore studied the effects of moderate hypothermia on cardiac and vascular function in pig ischemic CS treated with veno-arterial extracorporeal membrane oxygenation (VA-ECMO). CS was induced in 12 anesthetized pigs by coronary ligation. After 1 h of CS, VA-ECMO was initiated and pigs were randomized to normothermia (38°C) or moderate hypothermia (34°C) during 8 h. Intrinsic cardiac function was measured using a left ventricular conductance catheter. At the end of the experiment, tissues were harvested for Western blotting. ECMO associated with norepinephrine infusion and volume resuscitation increased mean arterial pressure, mixed venous oxygen saturation as well as carotid, renal, and coronary blood flow without any differences between normothermia and hypothermia. Hypothermia was associated with less fluid and less norepinephrine infusion, lower lactate level, and higher urinary output. Vascular reactivity was superior in hypothermia comparatively to normothermia as expressed using norepinephrine dose-response curves. Pressure development during isovolumic contraction, left ventricular ejection fraction, and prerecruitable stroke work index were higher in the hypothermia group. There were no differences between normothermia and hypothermia with regard to carotid and mesenteric protein expression for iNOs, eNOS, and phospho AKt/AKt measured at the end of the experimentation. The incidence of surgical bleeding and coagulation disorders was the same in both groups. In conclusion, moderate and rapid hypothermia improves hemodynamics and cardiac and vascular function in a pig model of ischemic CS treated with ECMO.

Beneficial Effects of Norepinephrine Alone on Cardiovascular Function and Tissue Oxygenation in a Pig Model of Cardiogenic Shock.

INTRODUCTION: The present study was developed to investigate the effects of norepinephrine alone on hemodynamics and intrinsic cardiac function in a pig model of cardiogenic shock mimicking the clinical setting. METHODS: Cardiogenic shock was induced by 1-h ligation of the left anterior descending (LAD) artery followed by reperfusion. Pigs were monitored with a Swan-Ganz catheter, a transpulmonary thermodilution catheter, and a conductance catheter placed in the left ventricle for pressure-loop measurements. Measurements were performed before LAD occlusion, 1 h after LAD occlusion, and 4 h after myocardial reperfusion. RESULTS: Myocardial infarction and reperfusion was followed by cardiogenic shock characterized by a significant increase in heart rate and significant decreases in mean arterial pressure (MAP), mixed venous oxygen saturation (SVO2), left ventricular end-diastolic pressure (LVEDP), prerecruitable stroke work (PRSW), and cardiac power index (CPI). Lactate levels were significantly increased. The systemic vascular resistance index (SVRI) and global end-diastolic volume index (GEDVI) remained unchanged. When compared with the control group (n = 6), norepinephrine infusion (n = 6) was associated with no changes in heart rate, a significant increase in MAP, SVO2, left ventricular ejection fraction, pressure development during isovolumic contraction, SVRI, and CPI and a decrease in lactate level. Cardiac index tended to increase (P = 0.059), whereas PRSW did not change in the norepinephrine group. LVEDP and GEDVI remained unchanged. CONCLUSIONS: Norepinephrine alone is able to improve hemodynamics, cardiac function, and tissue oxygenation in a pig model of ischemic cardiogenic shock.

Mechanisms of vascular hyporesponsiveness in septic shock.

PURPOSE: To define some of the most common characteristics of vascular hyporesponsiveness to catecholamines during septic shock and outline current therapeutic approaches and future perspectives. METHODS: Source data were obtained from a PubMed search of the medical literature with the following MeSH terms: Muscle, smooth, vascular/physiopathology; hypotension/etiology; shock/physiopathology; vasodilation/physiology; shock/therapy; vasoconstrictor agents. RESULTS: NO and peroxynitrite are mainly responsible for vasoplegia and vascular hyporeactivity while COX 2 enzyme is responsible for the increase in PGI2, which also contributes to hyporeactivity. Moreover, K+ATP and BKCa channels are over-activated during septic shock and participate in hypotension. Finally, other mechanisms are involved in vascular hyporesponsiveness such as critical illness-related corticosteroid insufficiency, vasopressin depletion, dysfunction and desensitization of adrenoreceptors as well as inactivation of catecholamines by oxidation. CONCLUSION: In animal models, several therapeutic approaches, targeted on one particular compound have proven their efficacy in preventing or reversing vascular hyporesponsiveness to catecholamines. Unfortunately, none have been successfully tested in clinical trials. Nevertheless, very high doses of catecholamines ( > 5 µg/kg/min), hydrocortisone, terlipressin or vasopressin could represent an alternative for the treatment of refractory septic shock.

Cardiac contractile reserve parameters are related to prognosis in septic shock.

INTRODUCTION: Cardiac reserve could be defined as the spontaneous magnitude from basal to maximal cardiac power under stress conditions. The aim of this study was to evaluate the prognostic value of cardiac reserve parameters in resuscitated septic shock patients. METHODS: Seventy patients with septic shock were included in a prospective and observational study. Prior to inclusion, patients were resuscitated to reach a mean arterial pressure of 65-75 mmHg with an euvolemic status. General, hemodynamic, and cardiac reserve-related parameters (cardiac index, double product, and cardiac power index) were collected at inclusion and at day 1. RESULTS: Seventy patients were included with 28-day mortality at 38.5%. Ten of the 70 patients died during the first day. In multivariate analysis, independent predictors of death were SAPS II ≥ 58 (OR: 3.36 [1.11-10.17]; P = 0.032), a high double product at inclusion (OR [95% IC]: 1.20 [1.00-1.45] per 10(3) mmHg · min; P = 0.047), and at day 1, a decrease in cardiac index (1.30 [1.08-1.56] per 0.5 L/min/m(2); P = 0.007) or cardiac power index (1.84 [1.18-2.87] per 0.1 W/m(2), P = 0.008). CONCLUSION: In the first 24 hours, parameters related to cardiac reserve, such as double product and cardiac index evolution, provide crucial and easy to achieve hemodynamic physiological information, which may impact the outcome.

[The pathophysiology of septic shock]. / La physiopathologie du choc septique.

Understanding of the pathophysiology of septic shock has benefitted from recent advances. These advances enable the validation of current treatment but also the development of new therapeutic approaches.

[Nursing management of ventilation and sedation in patients suffering from septic shock]. / La prise en charge infirmière de la ventilation et de la sédation chez le patient en choc septique.

A significant number of intubated, ventilated and sedated patients suffering from septic shock develop acute respiratory distress syndrome (ARDS). The supervision by a multidisciplinary team optimises both the management of ventilation and the sedation analgesia of the patient. The nursing supervision and care related to this pathology are specific.