Shock

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ACUTE

all patients

1st line – assessment of airway, breathing, and circulation

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1st line –

assessment of airway, breathing, and circulation

Assessment and treatment proceed alongside each other. At this stage the etiology of shock may not be clear. Key first steps are to ensure a patent airway (through intubation if required) and to optimize oxygen delivery with supplemental oxygen, commonly aiming for arterial oxygen saturations of 94% to 98%.[34] Routine supplementation of oxygen to achieve higher oxygen saturations has been linked to coronary and pulmonary arterial vasoconstriction in acute myocardial infarction.[68][69] For patients with sepsis-induced hypoxemic respiratory failure, high-flow nasal oxygen is recommended over noninvasive ventilation.[2]

Continuous monitoring is imperative to monitor response to therapy and to guide treatment. This includes clinical observation, repeated blood pressure readings, respiratory rate, oxygen saturations, pulse, level of consciousness, and monitoring of cardiac rhythm. In the critical care setting, continuous capnography can aid the assessment of shock.[36] Side stream or direct capnography (when endotracheal airway is in place) can be helpful in assessing pulmonary perfusion matched to ventilation.[36] The lactate level will usually decrease if the patient is clinically improving.[2] Treatment is dependent on continuous monitoring of these variables and guided by their response.

Plus – treatment of underlying cause

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Plus –

treatment of underlying cause

Treatment recommended for ALL patients in selected patient group

The underlying cause of shock needs to be identified as rapidly as possible. It indicates the most critical treatment priorities.

Identification of cardiogenic shock is important because aggressive fluid administration may worsen the shock state and lead to the onset (or worsening) of acute pulmonary edema. Early involvement of specialist multidisciplinary teams (e.g., heart failure and critical care specialists, interventional cardiologists, and cardiac surgeons) is recommended when cardiogenic shock is suspected.[4]

In cardiogenic shock secondary to a large myocardial infarction, urgent revascularization of the coronary arteries, by percutaneous coronary intervention, direct coronary infusion of thrombolytics, or cardiovascular surgery, lowers mortality.[50][84]

Severe rhythm disturbances should be corrected urgently in patients with acute heart failure and unstable conditions, using medical therapy, electrical cardioversion, or temporary pacing.[3]

Cardiac tamponade needs drainage; pericardiocentesis under ECG monitoring can have an effect by draining as little as 30 mL, but this may be unsuccessful if the blood is clotted. A pericardial drain or surgical pericardial window may be required.

In pulmonary embolism, shock is the most widely accepted indication for thrombolysis.[110][111] Emergency embolectomy is an alternative, especially when thrombolysis is contraindicated or has failed.

For anaphylactic shock, intramuscular epinephrine (adrenaline) is recommended as the most important treatment by all major guidelines.[63][64][65]

Early recognition and treatment of septic shock is key to improving outcomes. Current best practice is based on evidence for care bundles in sepsis.[2][89][90][91] The Surviving Sepsis Campaign (SSC) treatment guidelines remain the most widely accepted standards.[2] The SSC guidelines recommend obtaining blood cultures prior to the administration of antibiotics; administering antimicrobials immediately, ideally within 1 hour of recognition (in adults with possible septic shock or a high likelihood for sepsis); administering empiric antimicrobials with MRSA coverage in patients with sepsis or septic shock at high risk of MRSA; administering 30 mL/kg crystalloid for hypotension within the first 3 hours of resuscitation; obtaining serial measurement of blood lactate; aiming for a mean arterial pressure of ≥65 mmHg in patients with septic shock on vasopressors. For adults with an initial diagnosis of sepsis or septic shock, and adequate source control where optimal duration of therapy is unclear, a combination of procalcitonin and clinical evaluation is recommended to decide when to discontinue antimicrobials.[2] The SSC suggests intravenous corticosteroids in adults with septic shock and an ongoing requirement for vasopressor therapy.[2]

Hemorrhagic shock due to trauma requires a team approach with attention to identification of cause for, and control of, hemorrhage as soon as possible. Massive hemorrhage due to trauma is often associated with fibrinolysis, which further exacerbates hemorrhage by inhibiting clot formation. Antifibrinolytic agents may have a beneficial effect in addition to fluid and blood transfusion in stabilizing a trauma patient with shock.[92] Overly aggressive fluid infusion may increase the bleeding rate in hemorrhagic shock: in particular, when mean arterial pressures are >40 mmHg.[79]

Tension pneumothorax requires urgent decompression through needle thoracocentesis.

Needle decompression of tension pneumothorax: animated demonstration

How to decompress a tension pneumothorax. Demonstrates insertion of a large-bore intravenous catheter into the fourth intercostal space in an adult.

Consider – vasoactive agents

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Consider –

vasoactive agents

Treatment recommended for SOME patients in selected patient group

Short-term intravenous infusion of a vasoactive agent (vasopressor and/or inotrope) should be considered in patients with hypotension (systolic BP <90mmHg) and/or signs or symptoms of hypoperfusion, despite adequate filling status.[4]

Patients requiring vasoactive drugs (vasopressors/inotropes) need continuous monitoring in a critical care setting. Vasoactive agents may cause tachycardia, and induce arrhythmias and myocardial ischemia.[4] Selection of appropriate vasoactive agents should only take place under critical care supervision, and may vary according to the type of shock, clinician preference, and local practice guidelines.

Intravenous inotropic support can increase cardiac output and improve hemodynamics in patients presenting with cardiogenic shock.[4] There is a lack of robust evidence to suggest the clear benefit of one inotropic agent over another in cardiogenic shock.[80] In general, the choice of a specific inotropic agent is guided by blood pressure, concurrent arrhythmias, and availability of drug.[4] Inotropes should be used with caution because there is evidence that they result in increased mortality.[3][4][81] Inotropes should be discontinued if there are sustained arrhythmias or symptomatic coronary ischemia. Continuous monitoring of cardiac rhythm is recommended during infusion of inotropes.

Vasopressors are commonly recommended only after adequate volume resuscitation.[2][3] Dose is commonly titrated to achieve a mean arterial blood pressure of ≥65 mmHg, or a systolic blood pressure of ≥90 mmHg.[2][79][82] Vasopressors increase the risk of tissue ischemia and necrosis in a dose-dependent manner.

Consult a specialist for guidance on suitable vasopressor/inotrope regimens and doses.

cardiogenic shock not suspected

Plus – intravenous fluids

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Plus –

intravenous fluids

Treatment recommended for ALL patients in selected patient group

Evidence-based guidelines for the management of septic shock recommend 30mL/kg intravenous crystalloid fluid within the first 3 hours.[2] Ongoing management is guided by the continuous monitoring of organ perfusion and hemodynamics. Resuscitation in sepsis should be guided by dynamic measures rather than by physical exam or static measures alone. Dynamic parameters include the response to a passive leg raise or a fluid bolus, using stroke volume, stroke volume variation, pulse pressure variation, or echocardiography, where available. Predicting the effect of further volume in any individual patient requires considerable clinical judgment because no single, simple, and precise measure has been yet identified. Central venous pressure and ultrasonic parameters (central inferior vena cava diameter and collapsibility and aortic blood flow) are useful.[2][66][79] Commonly, systolic blood pressure of 90 mmHg or a mean arterial pressure of 65 mmHg is targeted during fluid volume resuscitation; infusion is stopped if concerns of volume overload develop (pulmonary rales or suspected pulmonary edema).

The major risk with volume resuscitation is pulmonary edema. In hemorrhagic shock, overly aggressive fluid infusion may increase the bleeding rate, in particular when mean arterial pressures are >40 mmHg.[79]

If there is no evidence for, or suspicion of, pulmonary edema secondary to cardiac failure, early fluid delivery is more important than the type of fluid (crystalloid or colloid).[71][72][73] There is no evidence for any survival benefit of colloid fluids over crystalloid.[73][112][113][114][115] [ ] [Evidence B] There is some evidence that balanced crystalloids may be preferable to normal saline in critically ill patients in intensive care, although other studies have found no difference.[76][116] The Surviving Sepsis Campaign recommends balanced crystalloids in patients with sepsis or septic shock.[2] In July 2021, the US Food and Drug Administration (FDA) issued safety labeling changes for solutions containing hydroxyethyl starch (HES) stating that HES products should not be used unless adequate alternative treatment is unavailable.[74] HES products are associated with adverse outcomes including kidney injury and death, particularly in critically ill patients and those with sepsis.[79][117] In view of the serious risks posed to these patient populations, the Pharmacovigilance Risk Assessment Committee of the European Medicines Agency in February 2022 recommended suspending HES solutions for infusion in Europe.[75] The Surviving Sepsis Campaign advises against the use of starches for patients with sepsis and septic shock.[2]

Consider – blood products

Consider – tranexamic acid

cardiogenic shock suspected

Consider – intravenous fluids

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Consider –

intravenous fluids

Treatment recommended for SOME patients in selected patient group

Early involvement of specialist multidisciplinary teams is recommended when cardiogenic shock is suspected (e.g., heart failure and critical care specialists, interventional cardiologists, and cardiac surgeons).[4] Aggressive fluid administration in the setting of cardiogenic shock may worsen the shock state and lead to the onset of acute pulmonary edema.

Intravenous fluids may be administered cautiously in the absence of signs of fluid overload (clinically determined by auscultation of the lungs to assess for rales or by chest radiography) in a patient with cardiogenic shock (e.g. small initial boluses [250mL] of crystalloid such as normal saline or Ringer lactate).[93]

Ongoing management is guided by the continuous monitoring of organ perfusion and hemodynamics. Predicting the effect of further volume in any individual patient requires considerable clinical judgment, because no single, simple, and precise measure has been yet identified. Central venous pressure and ultrasonic parameters (central inferior vena cava diameter and collapsibility and aortic blood flow) are useful.[66][79] Commonly, systolic blood pressure of 90 mmHg or a mean arterial pressure of 65 mmHg is targeted during fluid volume resuscitation; infusion is stopped if concerns of volume overload develop (pulmonary rales or suspected pulmonary edema).

Fluid delivery is more important than the type of fluid (crystalloid or colloid).[71][72][73] There is no evidence for any survival benefit of colloid fluids over crystalloid.[73][112][113][114][115] [ ] [Evidence B] There is some evidence that balanced crystalloids may be preferable to normal saline in critically ill patients in intensive care, although other studies have found no difference.[76][116] In July 2021, the US Food and Drug Administration (FDA) issued safety labeling changes for solutions containing hydroxyethyl starch (HES) stating that HES products should not be used unless adequate alternative treatment is unavailable.[74] HES products are associated with adverse outcomes including kidney injury and death, particularly in critically ill patients and those with sepsis.[79][117] In view of the serious risks posed to these patient populations, the Pharmacovigilance Risk Assessment Committee of the European Medicines Agency in February 2022 recommended suspending HES solutions for infusion in Europe.[75]

If there is acute inferior (right coronary artery) occlusion, or right ventricular infarct, hypotension is initially (before thrombectomy) corrected with careful fluid administration to improve right ventricular filling and overall cardiac output.[77]

Consider – nitroglycerin

Consider – temporary mechanical circulatory support (MCS)

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Consider –

temporary mechanical circulatory support (MCS)

Treatment recommended for SOME patients in selected patient group

Temporary MCS devices (e.g., extracorporeal membrane oxygenation or intra-aortic balloon pump) should be considered in patients with persistent cardiogenic shock maintained despite inotropic therapy.[3][4] Temporary MCS in appropriately selected candidates should be initiated as soon as possible with sufficient support to fully reverse the potential hemometabolic consequences of shock. If there is a delay to sufficient early support with temporary MCS, worsening end-organ perfusion and metabolic derangements can make future attempts difficult.[83] The hemodynamic benefits of the specific devices vary, and few head-to-head randomized comparisons exist. Vascular, bleeding, and neurologic complications are common to MCS devices, and the risk of such complications should generally be considered in the calculation to proceed with such support.[4] MCS requires specialist multidisciplinary expertise for implantation and management.[3] The escalation of either pharmacologic and mechanical therapies should be considered in the context of multidisciplinary teams of heart failure and critical care specialists, interventional cardiologists, and cardiac surgeons.[4][83]

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Shock

all patients

assessment of airway, breathing, and circulation

treatment of underlying cause

vasoactive agents

cardiogenic shock not suspected

intravenous fluids

blood products

tranexamic acid

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

cardiogenic shock suspected

intravenous fluids

nitroglycerin

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

temporary mechanical circulatory support (MCS)

Shock

Treatment algorithm

all patients

assessment of airway, breathing, and circulation

treatment of underlying cause

vasoactive agents

cardiogenic shock not suspected

intravenous fluids

blood products

tranexamic acid

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

cardiogenic shock suspected

intravenous fluids

nitroglycerin

Primary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

temporary mechanical circulatory support (MCS)