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.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-016-1189-5) contains supplementary material, which is available to authorized users.

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.

Lactate or ScvO2 as an endpoint in resuscitation of shock states?

In the current management of critically ill patients, variables such as blood pressure, urine output or central venous pressure guide resuscitative efforts. Unfortunately, global tissue hypoxia may persist leading to multiple organ failure and death. To address tissue well-being, indices such as central venous oxygen saturation (ScvO2) and Lactatemia are widely used and are strongly linked to outcome. Implementing these indices in haemodynamic optimization protocols have been shown to reduce morbidity and mortality in numerous studies especially in septic shock. Nevertheless, choosing one index over the other remains controversial. Herein, we review the physiology and rationale for ScvO2 and lactate monitoring. Clinical uses, evidence-based outcome implications and limitations are also examined to aid the clinician in daily practice.

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.

LACTATE or ScvO2 as an endpoint in resuscitation of shock states?

In the current management of critically ill patients, variables such as blood pressure, urine output or central venous pressure guide resuscitative efforts. Unfortunately, global tissue hypoxia may persist leading to multiple organ failure and death. To address tissue well-being, indices such as central venous oxygen saturation (ScvO2) and lactataemia are widely used and are strongly linked to outcome. Implementing these indices in haemodynamic optimization protocols have been shown to reduce morbidity and mortality in numerous studies especially in septic shock. Nevertheless, choosing one index over the other remains controversial. Herein, we review the physiology and rationale for ScvO2 and lactate monitoring. Clinical uses, evidence-based outcome implications and limitations are also examined to aid the clinician in daily practice. Key words: lactate, central venous oxygen saturation, shock, goal-directed therapy.

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.

[The pathophysiology of septic shock]

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]

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.

Vascular hyporesponsiveness to vasopressors in septic shock: from bench to bedside

PURPOSE

To delineate some of the characteristics of septic vascular hypotension, to assess the most commonly cited and reported underlying mechanisms of vascular hyporesponsiveness to vasoconstrictors in sepsis, and to briefly outline current therapeutic strategies and possible future approaches.

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

Nitric oxide (NO) and peroxynitrite are crucial components implicated in vasoplegia and vascular hyporeactivity. Vascular ATP-sensitive and calcium-activated potassium channels are activated during shock and participate in hypotension. In addition, shock state is characterized by inappropriately low plasma glucocorticoid and vasopressin concentrations, a dysfunction and desensitization of alpha-receptors, and an inactivation of catecholamines by oxidation. Numerous other mechanisms have been individualized in animal models, the great majority of which involve NO: MEK1/2-ERK1/2 pathway, H(2)S, hyperglycemia, and cytoskeleton dysregulation associated with decreased actin expression.

CONCLUSIONS

Many therapeutic approaches have proven their efficiency in animal models, especially therapies directed against one particular compound, but have otherwise failed when used in human shock. Nevertheless, high doses of catecholamines, vasopressin and terlipressin, hydrocortisone, activated protein C, and non-specific shock treatment have demonstrated a partial efficiency in reversing sepsis-induced hypotension.