Consensus on Circulatory Shock and Hemodynamic Monitoring.

RECOMENDATIONS

Hypotension and shock

We recommend that the presence of arterial hypotension [defined as systolic blood pressure of <90 mmHg, or mean arterial pressure (MAP) of <65 mmHg, or a decrease of ≥40 mmHg from baseline], while commonly present, should not be required to define shock. Recommendation. Level 1; QoE moderate (B).

Plasma lactate, mixed venous oxygen saturation and central venous oxygen saturation and other perfusion markers

We recommend measuring blood lactate levels in all cases where shock is suspected. Recommendation. Level 1; QoE low (C).
Lactate levels are typically >2 mEq/L (or mmol/L) in shock states. Statement of fact.
We recommend serial measurements of blood lactate. The rationale is to guide, monitor and assess. Recommendation. Level 1; QoE low (C).
In patients with a central venous catheter (CVC), we suggest measurements of central venous oxygen saturation (ScvO2) and venoarterial difference in PCO2 (V-ApCO2) to help assess the underlying pattern and the adequacy of cardiac output as well as to guide therapy. Recommendation. Level 2; QoE moderate (B).

Identification of the type of shock

We recommend efforts to identify the type of shock to better target causal and supportive therapies. Best practice.
We recommend further hemodynamic assessment (such as assessing cardiac function) to determine the type of shock if the clinical examination does not lead to a clear diagnosis. Best practice.
We suggest that, when hemodynamic assessment is needed, echocardiography is the preferred modality to initially evaluate the type of shock as opposed to more invasive technologies. Recommendation. Level 2; QoE (B).
We recommend not to use a single variable for the diagnosis and/or management of shock. Best Practice.
In complex patients we suggest to additionally use pulmonary artery catheterization or transpulmonary thermodilution to determine the type of shock. Recommendation. Level 2; QoE low (C).

Target blood pressure in circulatory shock

We recommend individualizing the target blood pressure during shock resuscitation. Recommendation. Level 1; QoE moderate (B).
We recommend to initially target a MAP of ≥65 mmHg. Recommendation. Level 1; QoE low (C).
We suggest to tolerate a lower level of blood pressure in patients with uncontrolled bleeding (i.e. bleeding patients from a road traffic accident) without severe head injury. Recommendation. Level 2; QoE low (C).
We suggest a higher MAP in septic patients with a history of hypertension and in patients who improve with higher blood pressure. Recommendation. Level 2; QoE moderate (B).
We recommend arterial and CVC insertion in cases of shock unresponsive to initial therapy and/or requiring vasopressor infusion. Best practice.

Therapeutic interventions to improve perfusion

We recommend early treatment, including hemodynamic stabilization (with fluid resuscitation and vasopressor treatment if needed) and treatment of the shock etiology. Best practice.
We suggest that inotropic agents should be added when the altered cardiac function is accompanied by a low or inadequate cardiac output and signs of tissue hypoperfusion persist after preload optimization. Recommendation. Level 2; QoE low (C).
We recommend not to give inotropes for isolated impaired cardiac function. Recommendation. Level 1; QoE moderate (B).
We recommend not to target absolute values of oxygen delivery in patients with shock.Recommendation. Level 1; QoE high (A).

Evaluation of response to therapy

We do not recommend routine measurement of cardiac output for patients with shock responding to the initial therapy. Recommendation. Level 1; QoE low (C).
We recommend measurements of cardiac output and stroke volume to evaluate the response to fluids or inotropes in patients that are not responding to initial therapy. Recommendation. Level 1; QoE low (C).
We suggest sequential evaluation of hemodynamic status during shock. Recommendation. Level 1; QoE low (C).

Monitoring preload and fluid responsiveness

Optimal fluid management does improve patient outcome; hypovolemia and hypervolemia are harmful. Statement of fact.
We recommend to assess volume status and volume responsiveness. Best practice.
We recommend that immediate fluid resuscitation should be started in shock states associated with very low values of commonly used preload parameters. Best practice.
We recommend that commonly used preload measures (such as CVP or PAOP or global end diastolic volume or global end diastolic area) alone should not be used to guide fluid resuscitation.Recommendation. Level 1; QoE moderate (B).
We recommend not to target any ventricular filling pressure or volume. Recommendation. Level 1; QoE moderate (B).
We recommend that fluid resuscitation should be guided by more than one single hemodynamic variable. Best practice.
We recommend using dynamic over static variables to predict fluid responsiveness, when applicable. Recommendation. Level 1; QoE moderate (B).
When the decision for fluid administration is made, we recommend to perform a fluid challenge, unless in cases of obvious hypovolemia (such as overt bleeding in a ruptured aneurysm). Recommendation, Level 1; QoE low (C).
We recommend that even in the context of fluid-responsive patients, fluid management should be titrated carefully, especially in the presence of elevated intravascular filling pressures or extravascular lung water. Best practice.

Monitoring cardiac function and cardiac output

Echocardiography can be used for the sequential evaluation of cardiac function in shock Statement of fact.
We do not recommend the routine use of the pulmonary artery catheter for patients in shock. Recommendation. Level 1; QoE high (A).
We suggest PAC in patients with refractory shock and RV dysfunction. Recommendation. Level 2; QoE low (C).
We suggest the use of transpulmonary thermodilution or PAC in patients with severe shock especially in the case of associated acute respiratory distress syndrome. Recommendation. Level 2; QoE low (C).
We recommend that less invasive devices are used, instead of more invasive devices, only when they have been validated in the context of patients with shock. Best practice.

Monitoring microcirculation