Sepsis represents the body’s overwhelming and life-threatening reaction to an infection. When faced with an infection, the immune system normally works to fight it off, but in sepsis, the response becomes dysregulated, causing the body to attack its own tissues and organs. This can lead to widespread inflammation, organ damage, and in severe cases, death.
While antibiotics are administered to combat the underlying infection, supportive therapy runs in parallel. The purpose of supportive care is not to cure the infection itself, but to maintain the function of the body’s essential systems. It is a series of interventions designed to keep organs working while the primary treatments take effect and the body recovers.
Managing Blood Pressure and Circulation
One of the pressing challenges in sepsis is a dramatic drop in blood pressure, a condition that can progress to septic shock. This occurs because the body’s inflammatory response causes blood vessels to dilate significantly. This expansion of the circulatory system’s volume means there is not enough fluid to fill it, leading to a sharp decline in pressure and preventing oxygen-rich blood from reaching organs.
To counteract this, the first line of treatment is the rapid administration of large volumes of intravenous (IV) fluids. Doctors use crystalloid solutions, which are salt-based fluids that quickly increase the volume of blood circulating through the body. This intervention is time-sensitive and involves infusing several liters of fluid within the first few hours of recognizing severe sepsis or septic shock.
If blood pressure does not respond adequately to IV fluids, medications called vasopressors are introduced. These drugs cause vasoconstriction, which is the tightening of blood vessels. This action reduces the overall volume of the circulatory system, which helps to increase blood pressure back toward a level that can sustain organ function. Norepinephrine is a first-line vasopressor in this setting.
The use of vasopressors requires careful management within an intensive care unit (ICU). Patients receiving these medications are monitored constantly, with their blood pressure checked minute-by-minute through an arterial line that provides continuous readings. This close observation allows the medical team to adjust the medication dose precisely, ensuring the blood pressure is raised enough to perfuse the organs without becoming dangerously high.
Mechanical Ventilation for Respiratory Support
The lungs are one of the first organs to be affected during sepsis. The same systemic inflammation that causes blood pressure to drop can also damage the delicate air sacs in the lungs, known as alveoli. This damage leads to Acute Respiratory Distress Syndrome (ARDS), a complication where fluid leaks from blood vessels into the lung tissue, making it difficult to breathe. Sepsis is a primary cause for about 70% of all ARDS cases.
When ARDS develops, a patient may require the support of a mechanical ventilator. This machine does not heal the damaged lungs; instead, it takes over the work of breathing for the patient. By delivering oxygen-rich air under controlled pressure, the ventilator ensures the body receives the oxygen it needs while allowing the patient’s respiratory muscles to rest, conserving energy to fight the infection.
To connect a patient to a ventilator, a procedure called intubation is performed. This involves placing a breathing tube through the mouth and into the windpipe. To ensure comfort, patients are given sedatives and pain medication while they are intubated. This allows the medical team to directly manage breathing, delivering precise amounts of oxygen to protect the lungs from further injury.
Support for Other Vital Organs
Beyond the circulatory system and lungs, sepsis can damage other organs, with the kidneys being particularly vulnerable. The severe drop in blood pressure from septic shock reduces blood flow to the kidneys, which can lead to acute kidney injury (AKI). Sepsis is the leading cause of AKI in critically ill patients, and its development worsens the prognosis.
When the kidneys fail, they lose their ability to filter waste products, toxins, and excess fluid from the blood. To perform this function, a form of dialysis is required. In the ICU setting, a method called continuous renal replacement therapy (CRRT) is used for septic patients. Unlike standard intermittent hemodialysis, CRRT is a much slower and gentler process that runs continuously, often for 24 hours a day.
This continuous nature makes CRRT better tolerated by hemodynamically unstable patients, as it avoids the rapid fluid shifts that can occur with shorter dialysis sessions. The machine draws blood from the patient, filters it through an artificial kidney to remove waste and excess water, and then returns the clean blood to the body. This provides constant support, helping to maintain chemical and fluid balance while the kidneys recover.
Metabolic and Nutritional Management
A severe illness like sepsis places the body under physiological stress, triggering a cascade of metabolic changes. The body’s energy requirements skyrocket as it mounts an immune response and attempts to repair damaged tissues. This leads to a hypercatabolic state, where the body begins to break down its own energy stores, including carbohydrates, fats, and proteins, at an accelerated rate.
Because patients with severe sepsis are often too ill to eat, providing nutritional support is a part of their care. The preferred route is enteral nutrition, where a liquid formula containing all necessary nutrients is delivered directly into the stomach or small intestine through a feeding tube. If the digestive system is not functioning properly, parenteral nutrition is used, delivering a specialized nutrient solution directly into the bloodstream through an intravenous line.
Another metabolic complication is stress-induced hyperglycemia, or high blood sugar. The inflammatory response and stress hormones released during sepsis can cause blood glucose levels to rise, even in individuals who do not have diabetes. This hyperglycemia can impair immune function and is associated with worse outcomes. To manage this, patients in the ICU are treated with a continuous intravenous infusion of insulin, with blood sugar levels checked frequently to allow for precise adjustments to the insulin rate.