Sepsis is a serious condition that occurs because of a complication with an infection. It occurs when chemicals released into the bloodstream to combat an infection trigger an inflammatory response throughout the entire body. Inflammation can cause extensive damage to various vital organs, and without treatment, those organs can fail. Additionally, if sepsis turns into septic shock, your blood pressure can suddenly and dramatically drop. For that reason, if sepsis is not treated properly and promptly, it can be life-threatening.
Sepsis occurs in three stages:
– Sepsis – Severe sepsis – Septic shock
Stage one: Systemic Inflammatory Response Syndrome (SIRS)
Sepsis can be hard to identify but is typically denoted by an extremely high or low body temperature, high heart rate, high respiratory rate, high or low white blood cell count and a known or suspected infection. The signs are used to identify Systemic Inflammatory Response Syndrome (SIRS), which only becomes sepsis when an infection is present.
SIRS is, in some circles, a more commonly used term because sepsis is only seen as a subcategory of SIRS. For sepsis, two of the mentioned SIRS signs, as well as an infection, need to be present.
Stage two: severe sepsis
The second stage, called severe sepsis, is diagnosed when acute organ dysfunction begins. Severe sepsis can also be diagnosed when sepsis is present along with hypotension (low blood pressure) or hypoperfusion (decreased blood flow through an organ).
Organ dysfunction is characterized by symptoms such as decreased urine output, sudden changes in mental state, decreased blood platelet count, difficulty breathing, abnormal heart pumping function and abdominal pain. Partly because of this, urine output is one of the factors measured in the SSC Sepsis 6 bundle immediately after diagnosis of sepsis to track progression.
Stage three: septic shock
Septic shock is the most severe stage of sepsis. It is defined as the presence of hypotension, induced by sepsis, despite fluid resuscitation. In addition, perfusion abnormalities such as elevated lactate levels. Septic shock has the highest chance of mortality, with estimates ranging from 30% to 50%.
Human sepsis is thought to be systemic inflammatory response syndrome (SIRS) that is activated by invasive infection. The multiple organ dysfunction syndrome (MODS) is the identified failure of critical organ function in patients that have sustained SIRS. Because SIRS and MODS are consequences of the excessive activation of inflammation, extensive research and numerous clinical trials have pursued treatments that would modify the inflammatory response.
MODS Flow Chart
Renal dysfunction in MODS is reflected in impairment of normal selective excretory function, initially in oliguria despite adequate intravascular volume, but later in a rising creatinine level (>5.0), and fluid and electrolyte derangements of sufficient magnitude that dialysis is required. Its causes are both pre-renal and renal. Reduced renal blood flow secondary to systemic hypotension, altered regional perfusion, or increased intra-abdominal pressure is an early risk factor; evolution of the disorder is compounded by pre-existing physiologic deficit and the effects of nephrotoxic drugs.
SIRS is the initial infection stage to enter Sepsis, it is one of the most difficult aspects of sepsis care in diagnosing it on time and providing proper treatment.
Temperature > 38.5ºC or < 35ºC (body temperature alterations which are known as hyperthermia or hypothermia)
Heart rate >90 beats/min (Tachycardia)
Respiratory rate >20 breaths/min or PaCO2 < 32 mmHg (Tachypnoea)
WBC >12,000 cells/mm3 or < 4000 cells/mm3, or >10 percent immature (band) forms (leukocytosis or leukopenia)
Sepsis (SIRS + Source of Infection)
Suspected or present source of infection
Severe Sepsis (Organ Dysfunction, Hypotension, or Hypoperfusion)
Lactic acidosis, SBP <90 or SBP drop ≥ 40 mm Hg of normal
Severe sepsis with hypotension, despite adequate fluid resuscitation.
MODS (Multiple Organ Dysfunction Syndrome Criteria)
Evidence of ≥ 2 organs failing
Cause of Sepsis (Systemic Inflammation)
The most common cause of Sepsis is severe systemic inflammation. As a result, multiple organ systems and organs can fail. Organ dysfunction and organ shutdown symptoms can be estimated by using a scoring system called Sequential Organ Failure Assessment (SOFA). When a patient’s SOFA score increases more than two points, significant organ dysfunction is present. A simplified SOFA score (qSOFA) has been proposed as a rapid bedside tool for the diagnosis of sepsis outside of the ICU.
Injuries to the organs increase mortality rates if the infection causes a lower blood pH. The risk of death increases dramatically with the severity of organ dysfunction and the number of failing organs.
Types of Organ Failure
Analysis of organ dysfunction of kidney failure with Sepsis data in tableau
I will start with the description of the kidney.
The kidneys are a pair of red, bean-shaped organs about the size of your fist, located on either side of the lower back. Most people have two working kidneys, but you can live well with only one kidney if it’s working correctly.
Your kidneys’ major function is to filter waste and toxins from the blood then excrete them along with excess water as urine, but the activities of your kidneys affect many other important processes in the body.
When your kidneys don’t work correctly, waste products build up in your body. If this happens, you’ll feel sick and eventually die without treatment. Many people can manage kidney failure with proper treatment.
What is kidney failure?
Kidney failure (renal failure) means one or both of your kidneys no longer function well on their own. Kidney failure is sometimes temporary and develops quickly (acute). Other times it’s a chronic (long-term) condition that slowly gets worse.
Kidney failure is the most severe stage of kidney disease. It’s fatal without treatment. If you have kidney failure, you may survive a few days or weeks without treatment.
Signs of Kidney Failure
Kidney failure can happen for a few reasons:
The infection that leads to sepsis started in the kidneys
The effects of the condition have damaged the kidneys
Blood pressure drops extremely low, affecting how blood flows through the body.
All these things will have a negative impact on the function of your kidneys, and since the kidneys are responsible for filtering blood and waste products and turning them into urine if they are not functioning properly, your urine output will decrease.
Decreased output of urine
As sepsis advances and becomes severe sepsis, you could experience a marked decrease in the amount of urine you are producing. As mentioned, several times, this condition can do damage to all vital organs, including the kidneys. As the body becomes more overwhelmed by the condition, organs start shutting down and the kidneys are usually one of the first organs to be affected.
Sepsis Dataset Overview
The Sepsis dataset has 43 features or fields which can broadly be classified into
• Vital Signs or Clinical
• Laboratory values
In the Sepsis dataset, there is a feature called Sepsis Label which indicates whether a patient has sepsis on admission or not. The sepsis label holds either a 0 or 1 value. When a patient is admitted to the hospital, one of the following happens:
• Sepsis label is 0 (No sepsis on admission)
• Sepsis label is converted from 0 to 1(No sepsis on admission and then converted to sepsis)
• Sepsis label 1 (Sepsis on Admission)
Segregation of Sepsis Patients
From the visualization, of the total 40,336 patients, we can see that 37,404(92.73%) are non-Sepsis patients. Around 2506(6.21%) are Onset Sepsis and only 426(1.06%) are confirmed, Sepsis patients.
We can create a calculated field for isolating non-Sepsis patients exhibiting two or more SIRS symptoms. Out of 37,404 patients, 25,119 patients had SIRS symptoms.
Analysis of how sepsis affects the kidneys in tableau
There are two ways sepsis can affect the kidneys. The first is if the infection that caused the sepsis begins in the kidney through a kidney infection or a bladder infection that has spread to the kidney. The second is if the cascade of events from sepsis causes kidney damage.
In sepsis and septic shock, your blood pressure drops dangerously low, affecting how the blood flows through your body. Because the blood can’t flow as quickly as it should, it can’t deliver the nutrients needed by the body’s tissues and organs. At the same time, the blood begins to clot within the blood vessels slowing down blood flow even more.
Criteria for kidney failure analysis
SBP <90 or SBP drop > 40 mm Hg
MAP<60 mm Hg
Creatinine >5.0 mg/dL
BUN >60 mg/dL
Resp >22 breaths per minute
Patients count with kidney failure
The graph shows 67 patients count with kidney failure. This is the analysis for each hour of how many patients diagnosed with kidney failure. So, the numbers you can see on the edge of the outer part are hours. As you see at hour 5, I am getting number of patients 4. Now we will see some detailed analysis of 5 Biomarkers with sepsis patients.
Analysis of Sepsis Patient
The Tableau Visualization of kidney failure patients. One calculated field is created, which filters the patients that satisfy the criteria. This visualization includes the patient ID, Hour, previous hour (Kidney...), systolic blood pressure as SBP, mean arterial pressure as MAP, creatinine, blood urea nitrogen as bun, respiration as Resp, and sepsis label. Here colors used are against each condition. Then it will be easier for the doctors to identify the condition. Now let’s discuss the calculated field more. Sepsis possibility is the name of the calculated field, which contains the logic of the nested if statement. Each color shows satisfactory criteria. I gave two assorted colors for the previous hour and the satisfied hour. You can see the patient id 4786 SBP and MAP level at hours 14 and 15. Now we will understand how creatinine and bun affect sepsis with kidneys.
What Is the creatinine level for kidney failure
A creatinine level of greater than 1.2 for women and greater than 1.4 for men may be an early sign that the kidneys are not working properly. As kidney disease progresses, the level of creatinine in the blood rises. This test measures how well the kidneys are removing wastes and excess fluid from the blood. I took creatinine >5 to find the patients whose kidney got failed.
Analysis with Gender
As I mentioned above, the level of early sign that the kidneys are not working properly. From this visualization, Doctors can clearly see the levels where the patients are and make an immediate decision for future medication. And the red color shows extremely high that means their kidney got already failed.
A BUN test (blood urea nitrogen) tells you if a substance called urea is building up in the blood, an indicator that the kidneys are not filtering waste properly. When someone has sepsis or septic shock, the doctors work to treat the sepsis, the infection that caused the sepsis, and the damage that the sepsis has done, such as kidney failure.
From the Visualization, in caption I mentioned about BUN ranges. So here extremely high is above 60 that indicates kidney failure.
Bun / Creatinine Ratio
BUN and creatinine tests can be used together to find the BUN-to-creatinine ratio (BUN: creatinine), which is more specific than the BUN test alone. More specific tests such as glomerular filtration rate (GFR) and creatinine clearance may be performed further to diagnose kidney failure.
We may look at the BUN / Creatinine ratio to help determine the cause of renal failure. The ratio of BUN to creatinine is usually between 10:1 and 20:1. An increased ratio may be due to a condition that causes a decrease in the flow of blood to the kidneys, such as CHF or dehydration.
Correlation between BUN and Creatinine
From this visualization, you can see the correlation between BUN and creatinine. The bar shows the creatinine level for each patient and the line shows the BUN level for each patient and their correlation. I segregate the color light and dark. So, the darker the color is high correlate and lighter is low correlate. So, if your BUN Creatinine Ratio is High, your physician will decide what this means for you. If you have Acute Renal Failure, and your BUN and Creatinine are both elevated, high BUN Creatinine Ratio may indicate that your kidneys are failing due to dehydration.
In patients with sepsis-associated AKI, appropriate fluid resuscitation and maintenance of blood pressure are important to prevent further kidney damage. Without proper treatment for this underlying condition organs can fail quickly. With this analysis it will be helpful to get immediate care with severe septic shock patients with kidney related problems.