What is Septic Shock?
Sepsis is a condition that can range in severity and it forecasts how serious the illness can get. Septic shock, the most serious stage of sepsis, can be fatal. When your body tries to fight off an infection, it triggers both the pro-inflammatory (triggers inflammation) and anti-inflammatory (reduces inflammation) parts of your immune system. This process also involves the activation of certain types of white blood cells that respond to infections, like monocytes, macrophages, and neutrophils. These cells cooperate with the inner lining of your blood vessels (the endothelium) to produce various substances, including cytokines (small proteins), proteases (enzymes that break down proteins), kinins (peptides that cause blood vessel dilation), reactive oxygen species (free radicals), and nitric oxide.
The endothelium is the primary area where this immune response takes place. It can suffer damage itself and even activate blood clotting and immune responses that further harm blood vessels, leading to leakage from capillaries (the smallest blood vessels). This reaction sequence causes the signs and symptoms of sepsis and can lead to the progression from sepsis to septic shock.
How well your body can balance the inflammatory response to get rid of the infection and the anti-inflammatory response to control overall inflammation contributes to how sick you will get and whether or not you may die from the condition.
Treatment measures that are started early, such as antibiotics, following sepsis care plans, and working on achieving treatment goals as soon as possible, have greatly improved the survival rates of people with sepsis. However, being able to identify sepsis as early as possible still remains the best approach to treating and managing this condition.
What Causes Septic Shock?
A comprehensive study in 2009 discovered that infections caused by gram-negative bacteria are the most prevalent reason for sepsis syndromes, accounting for 62% of cases. This type of bacteria surpassed other causes such as gram-positive bacterial infections, which accounted for 47%. One reason for the rise in gram-positive infections could be due to more invasive medical procedures and a growing number of infections picked up in hospitals.
Common bacteria found in patients included Staphylococcus aureus (20%), Pseudomonas (20%), and Escherichia coli (16%). The most common infections were located in the respiratory system (42%), the bloodstream (21%), and the genitourinary system — which covers organs like the kidneys and bladder (10%). However, it’s important to remember that in over a third of patients, no bacteria were found in cultures.
An analysis of multiple studies showed that the type of bacteria and where the infection is located can affect the chance of survival. Generally, gram-negative infections led to a higher risk of death. But serious gram-positive infections – like blood infections caused by Acinetobacter bacteria or pneumonia from Staphylococcus bacteria – were associated with a 40% mortality rate. Pneumonia caused by Pseudomonal bacteria had the highest death rate at 70%.
The occurrence of sepsis caused by bacteria resistant to multiple drugs, including MRSA and VRE, is increasing, currently seen in up to 25% of cases. Cases caused by viruses and parasites are less common, making up 2% to 4% of cases.
There are several factors that increase the risk of developing sepsis, including:
- Diabetes
- Cancer
- Chronic kidney and liver disease
- Use of corticosteroids, which are medicines often used to reduce inflammation
- Weakened immune system
- Burn injuries
- Major surgery
- Physical trauma
- Use of indwelling catheters, which are tubes inserted into the body to drain fluids
- Extended hospital stays
- Having hemodialysis, a treatment for kidney failure
- Young or old age
Risk Factors and Frequency for Septic Shock
Sepsis, a serious medical condition, has seen its incidence rate increase drastically over the years. Every year, the number of these dire cases rises by almost 9%. In fact, the number of hospitalizations due to sepsis has grown from around 600,000 to over 1,000,000 each year from the years 2000 to 2008. This increased number of cases also means that more money is being spent on treating sepsis. In 2009, it became the most expensive health condition to treat, making up 5% of all hospital costs in the United States.
It’s not all bad news, though. The establishment of the Surviving Sepsis Campaign has helped improve the management and treatment of sepsis. This has resulted in a reduction of death rates for sepsis patients, going from 16.5% down to 13.8% from 2009 to 2012.
However, severe sepsis is still a significant challenge, ranking as one of the leading causes of deaths in hospital settings. Up to 25% of severe sepsis patients and 50% of septic shock patients may unfortunately not survive. Sepsis still poses a high overall death rate varying from 30% to 50%, depending on various factors like age, race, gender, other pre-existing health conditions, and the severity of organ dysfunction.
For patients admitted to the hospital, the chances of survival are usually lower if they have severe organ injuries, especially in their respiratory system, cardiovascular system, liver, and brain.
Signs and Symptoms of Septic Shock
Sepsis is a condition that arises when the body’s response to an infection injures its own tissues and organs. In the beginning stages, sepsis patients often show certain changes in their vital signs:
- Fever with a temperature higher than 38 C, or low body temperature below 36 C
- Fast heart rate, more than 90 beats per minute in adults or higher than average for age in children
- Rapid breathing, over 20 breaths per minute in adults or more than what’s typical for age in children
As sepsis becomes more severe, it can lead to dysfunction of the body’s organs. By this point, the signs and symptoms could include:
- Changes in mental function
- Producing little or no urine
- Low levels of oxygen
- Blue or purple color to the skin, lips or fingernails
- Stomach or intestinal problems, for example, an ileus (a failure of the intestines to contract normally to move waste along)
When severe sepsis transforms into septic shock, it results in extremely low blood pressure. Initially, the body can still maintain blood pressure, and other symptoms like warm skin, quick skin recovery time after being pressed (less than one second), and strong pulses may appear. This state of shock, if treated promptly with fluids and medications to increase blood pressure, can be reversed. As septic shock advances, blood pressure can drop resulting in cold skin, slow skin recovery time after being pressed (more than three seconds), and weak pulses. If left untreated, this can rapidly lead to dysfunction of multiple body organs and potentially, death.
Testing for Septic Shock
If you’re diagnosed with sepsis, severe sepsis, or septic shock, you might see several changes in your body. These can include:
- Hyperglycemia: Your blood sugar might be higher than usual, more than 120 mg/dL.
- Changes in white blood cells count: You might have too many (more than 12,000/mm3 – a condition called leukocytosis) or too few (less than 4,000/mm3 – a condition called leukopenia).
- Bandemia: This means there are too many immature white blood cells in your blood (more than 10%).
- Increased C-reactive protein or procalcitonin: These can increase to more than 2 standard deviations above the normal.
- Mixed venous saturation: This might be more than 70%.
- Changes in oxygen levels: PaO2: FiO2 (a measure of oxygen levels in your blood) might be less than 300.
- Pre-renal azotemia: This is a condition where there is too much nitrogen waste product in your blood.
- Coagulopathy: This means your blood takes too long to clot, measured by an INR more than 1.5 or PTT more than 60 sec.
- Thrombocytopenia: Your platelet count, which helps blood clot, might be less than 100,000/mL.
- Hyperbilirubinemia: The levels of bilirubin, a waste product of red blood cells, might be more than 4 mg/dL.
- Lactic acidosis: Lactic acid levels might be more than 2 mmol/L, which can indicate that your body isn’t getting enough oxygen.
If you’re diagnosed with one of these conditions, doctors will likely monitor your heart and lungs continuously. They’ll also carefully check every organ in your body to see how well they’re working. They may perform various tests like a Glasgow Coma Scale or mental status assessment to check for problems with your brain, and measure how much urine you produce.
Your doctor will also order various tests to learn more about the disease. These include a complete blood count, cultures from various parts of your body like blood or urine, and a urinalysis. Depending on your symptoms and age, a lumbar puncture might be needed for instance if there are signs of brain inflammation or in young children with fever.
Your doctor may also order a test to measure C-reactive protein or procalcitonin, which can indicate if you have a bacterial infection. Other tests which might be useful include a chemistry panel with liver function tests, a clotting disorder panel, and an arterial blood gas.
It’s also very important to obtain blood cultures before starting antibiotics. However, less than 40% of these cultures are positive.
Imaging tests like a chest X-ray can reveal lung infections or other lung problems. If the doctor suspects a severe skin infection, an X-ray of the affected area might show gas in the tissues. Ultrasound can help to examine the gallbladder, and a CT scan can be used to check the abdomen for abscesses, bowel perforation, or loss of blood supply.
Treatment Options for Septic Shock
The below guidelines come from the Surviving Sepsis Campaign Guidelines, which are designed to help doctors treat sepsis effectively.
Immediate treatment for sepsis often involves:
– Giving broad-spectrum antibiotics within one hour of diagnosis. Think of these as general-disease-fighting tools that can work against many different types of bacteria.
– Removing any infected or dead tissue if it’s causing the sepsis. This could be relevant if someone has a skin infection, abscess, contaminated medical device, or infected wounds.
Restoring your body’s vital functions is also crucial:
– The best outcomes are seen within the first six hours after diagnosis,
– Your doctor will ensure that the pressure involved in circulating blood (central venous pressure) is restored to its general range,
– Your arterial pressure is brought back to a normal level,
– Your superior vena cava, one of the large veins carrying blood into the heart, is saturated to 70%,
– The doctor will also try to give your body back the hydration and nutrients (crystalloid) it needs, along with other substances (colloid),
– A mechanical breathing machine (mechanical ventilation) can be used to help regulate your energy consumption
– First-line vasoactive agents, such as epinephrine and norepinephrine (medications that help to increase blood pressure and heart rate), may be used if fluids alone aren’t showing improvement.
Boosting your body’s natural defence systems is also essential. This can be done by using medicine like corticosteroids and vasopressin that can help your body respond better to stress and inflammation when other measures aren’t enough.
While getting a central line (a long, thin tube inserted into a large vein) is not always required, it can help in monitoring certain vital signs and fluid levels. Intravenous medication can sometimes be given safely through a vein in your arm instead.
The doctors will keep track of your body’s oxygen levels and blood pressure continually. They will monitor these through regular blood samples and devices that can measure your blood pressure continuously.
If you have sepsis, your body’s energy levels may be high, meaning starvation should be avoided. Giving nutrition early can help protect your gut and prevent bacteria from moving from your digestive system to other parts of your body.
What else can Septic Shock be?
When looking at sudden and severe health conditions, medical professionals may consider the following:
- Acute respiratory distress syndrome (ARDS), a severe lung condition causing shortness of breath.
- Disseminated intravascular coagulation (DIC), a condition that causes blood clots throughout the body.
- Distributive shock, a serious condition where blood flow is reduced to vital organs.
- Hemorrhagic shock, which is caused by severe blood loss.
- Adrenal crisis, a condition where the adrenal glands can’t produce enough hormones.
- Cardiogenic shock, a condition where the heart suddenly can’t pump enough blood to meet the body’s needs.
- Toxic shock syndrome, a severe bacterial infection.
- Drug toxicity, a severe reaction to a medication or drug.
What to expect with Septic Shock
Septic shock is a severe medical condition and despite modern advancements in medicine, it often has a high mortality rate, sometimes exceeding 40%. The survival rate varies and depends on several factors such as: the type of bacteria causing the condition; how sensitive these bacteria are to antibiotics; how many body organs are affected; and the age of the patient.
The mortality rate increases the more the patient’s condition aligns with what’s called the Systemic Inflammatory Response Syndrome (SIRS) criteria. SIRS is a term used to describe the body’s response to severe infection which can lead to septic shock. For instance, rapid breathing and confusion or reduced alertness are strong indicators that the patient’s condition may lead to poor outcomes.
Also, if medication is needed for an extended period to keep the blood pressure stable, this can be an indicator of a more serious condition. It’s also important to remember that even those who survive septic shock may face significant challenges in their everyday functions and cognitive abilities.
Possible Complications When Diagnosed with Septic Shock
- Acute Respiratory Distress Syndrome (ARDS)
- Acute or Chronic Kidney Damage
- Disseminated Intravascular Coagulation (DIC – a condition that affects the blood’s ability to clot)
- Mesenteric Ischemia (an emergency condition caused by poor blood supply to the intestines)
- Acute Liver Failure
- Heart Muscle Dysfunction
- Failure of Multiple Organs
