Essential 102: Septic Shock

Managing Hypotensive Patients with Septic Shock

Author: Dr Vaibhav Singh, KGMU

Definitions

Shock is a condition where there is insufficient perfusion of vital organs. It can result from factors like low intravascular volume, as seen in hemorrhagic or hypovolemic shock, or abnormal circulatory distribution, such as in neurogenic or septic shock.
Central Venous Catheter: An intravenous tube used to measure pressures in the superior vena cava.
Echocardiography: A noninvasive imaging method to assess heart function and fluid volume status, useful for critically ill patients.
Serum Lactate: An indicator of oxygen deficiency in the body, which can also rise due to issues like kidney dysfunction.
Pulmonary Artery Catheter: An invasive catheter that measures heart-related pressures, primarily used for patients with poor cardiac function on inotropic agents.

Clinical Approach

Hypotension leading to shock can result from various factors like low intravascular volume, cardiac dysfunction, or acute vasodilation without adequate fluid increase. A systematic approach to such patients is crucial to reduce organ perfusion deficits and the risk of multiple organ dysfunction syndrome (MODS). This approach involves monitoring key parameters like central venous pressure (CVP), mean arterial pressure (MAP), and serum lactate. Specific medications like norepinephrine and vasopressin may be used to support septic shock patients, along with considering corticosteroids in certain cases.

Diagnosis

Assessment and management of hypotensive patients entail close monitoring of vital signs, urine output, and clinical appearance, observing changes over time and after interventions. Additional measures such as Foley catheters for urine output, arterial blood gas measurements for base deficit and lactate trends, and arterial catheterization for continuous blood pressure monitoring can be helpful. Central venous monitoring and echocardiography provide valuable information for identifying the causes of hypotension and guiding treatment.

Types of Shock

1. Hypovolemic Shock: Due to low intravascular volume, often from ongoing bleeding in surgical patients, requiring source control and blood product administration.
2. Distributive Shock: Caused by changes in vascular tone, such as in neurogenic shock or septic shock, usually requiring vasoconstrictive medications instead of excessive fluid.
3. Sepsis: Hyperdynamic response to infections, with severe sepsis defined by organ dysfunction and septic shock by persistent hypotension despite fluid administration. Early Goal-Directed Therapy is crucial, focusing on early recognition, aggressive treatment, and timely antibiotics.
4. Cardiogenic Shock: Intrinsic (e.g., acute coronary syndrome, heart failure) or extrinsic (e.g., tension pneumothorax, cardiac tamponade) cardiac dysfunction. Diagnosis relies on EKG, troponin levels, and echocardiography.
5. Mixed Causes of Shock: Some patients may have multiple factors contributing to hypotension, necessitating careful evaluation and simultaneous treatment of the underlying conditions.

Treatment

The treatment of a hypotensive patient with septic shock is a medical emergency and requires immediate intervention. Septic shock is a severe condition where an infection spreads throughout the body and leads to a systemic inflammatory response, causing low blood pressure and multiple organ dysfunction. The goal of treatment is to restore adequate blood flow to vital organs and control the infection. Here are the key steps in managing a hypotensive patient with septic shock:

Early Recognition:

• Recognize the signs and symptoms of septic shock, which may include low blood pressure, rapid heart rate, altered mental status, fever or hypothermia, and signs of organ dysfunction (e.g., altered consciousness, difficulty breathing, low urine output).

Rapid Assessment:

• Assess the patient’s airway, breathing, and circulation (ABCs).
• Ensure that the patient has a patent airway and provide oxygen if needed.
• Start intravenous (IV) access for fluid resuscitation and medication administration.

Source Control:

• Identify and treat the source of infection, such as antibiotics for bacterial infections, drainage of abscesses, or removal of infected devices (e.g., catheters).

Fluid Resuscitation:

• Administer intravenous fluids (crystalloids like normal saline or balanced solutions) rapidly to restore intravascular volume. Initial fluid resuscitation is typically done with a bolus of 30 mL/kg of body weight over the first few hours.

Vasopressors:

• If the patient remains hypotensive despite fluid resuscitation, initiate vasopressor therapy (e.g., norepinephrine) to increase blood pressure and maintain perfusion to vital organs. Vasopressors are usually administered through a central venous catheter.

Hemodynamic Monitoring:

• Consider central venous pressure (CVP) monitoring and/or invasive arterial blood pressure monitoring to guide fluid and vasopressor therapy.

Antibiotics:

• Administer broad-spectrum antibiotics as soon as possible based on the suspected or identified source of infection. Early administration of appropriate antibiotics is crucial.

Corticosteroids:

• In some cases, corticosteroids (e.g., hydrocortisone) may be considered if there is inadequate response to fluid resuscitation and vasopressors. This is typically reserved for cases with adrenal insufficiency or refractory shock.

Supportive Care:

• Provide supportive care, including mechanical ventilation for respiratory support, renal replacement therapy if needed, and other organ-specific interventions as necessary.

Consideration for Adjunctive Therapies:

• In some cases, adjunctive therapies like activated protein C or intravenous immunoglobulin may be considered, but their use is less common and should be guided by specific clinical circumstances.

Continuous Monitoring:

• Continuously monitor the patient’s vital signs, oxygenation, laboratory values, and response to treatment. Adjust therapy accordingly.

Consultation and Collaboration:

• Involve a multidisciplinary team, including infectious disease specialists and intensivists, in the management of the patient.

The management of septic shock is complex, and treatment should be individualized based on the patient’s clinical condition and response to therapy. Early recognition and prompt intervention are critical to improving outcomes in septic shock patients.

Overall, the approach to hypotensive patients with septic shock involves comprehensive assessment, timely intervention, and individualized treatment strategies based on the specific etiology of the shock.