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Analysis of SIRS, Sepsis and Stages of Sepsis

Systemic inflammatory response syndrome (SIRS) is an exaggerated defense response of the body to a noxious stressor that may be caused by an infection, trauma, surgery, ischemia (lack of blood supply to a part of the body), or certain conditions, such as an autoimmune disorder or pancreatitis. It is serious condition in which there is inflammation throughout the whole body. To be diagnosed with systemic inflammatory response syndrome, a person must have two or more of the following: low or high body temperature, increased heart rate, increased breathing rate, and an abnormal white blood cell count.

The clinical diagnostic criteria to define SIRS consist of two or more coexisting conditions:

  • Body temperature over 38 or under 36 degrees Celsius.

  • Heart rate greater than 90 beats/minute

  • Respiratory rate greater than 20 breaths/minute or partial pressure of CO2 (PaCO2) less than 32 mmHg

  • Leukocyte (WBC) count greater than 12000 or less than 4000 /microliters or over 10% immature forms or bands.

SIRS with a suspected source of infection is termed Sepsis. Sepsis is the body's extreme response to an infection. It is a life-threatening medical emergency. Sepsis happens when an infection you already have triggers a chain reaction throughout your body. Infections that lead to sepsis most often start in the lung, urinary tract, skin, or gastrointestinal tract. The infection-fighting processes turn on the body, causing the organs to work poorly. When germs get into a person’s body, they can cause an infection. If that infection is not stopped, it can cause sepsis. Bacterial infections cause most cases of sepsis. Sepsis can also be a result of other infections, including viral infections, such as COVID-19 or influenza, or fungal infections.

Anyone can develop SEPSIS, but following people are at higher risk:

  • Adults 65 or older

  • People with weakened immune system

  • People with chronic medical conditions, such as diabetes, lung disease, cancer, and kidney disease

  • People with recent severe illness or hospitalization

  • People who survived sepsis

  • Children younger than one

Severe sepsis can lead to septic shock, a medical emergency. Septic shock is associated with a significant drop in blood pressure, organ failure, and widespread tissue damage. If left untreated, it can be fatal.

Stages of sepsis

There are three stages of sepsis:

  • Sepsis: An infection gets into your bloodstream and causes inflammation in your body. Sepsis is when your immune system overreacts to an infection and starts to attack your body’s tissues and organs.

  • Severe sepsis: If Sepsis left untreated, toxins produced by bacteria can damage the small blood vessels, causing them to leak fluid into the surrounding tissues.This can affect your heart's ability to pump blood to your organs, which lowers your blood pressure and means blood doesn't reach vital organs, such as the brain and liver.The infection and inflammation is severe enough to start affecting organ function.

  • Septic shock: Septic shock is the last and most severe stage of sepsis. Septic shock is a severe complication of sepsis that causes a significant drop in blood pressure. This can lead to many serious complications including:

    • organ dysfunction

    • Kidney and Lung Damage

    • respiratory or heart failure

    • stroke

    • possible death

Criteria for Establishment of the Diagnosis of Sepsis, Severe Sepsis, and Septic Shock


SIRS with suspected source of infection

Severe Sepsis

Sepsis and at least 1 sign of organ hypoperfusion or organ dysfunction:

  • Areas of mottled skin

  • Capillary refilling time ≥3 s

  • Urinary output <0·5 mL/kg for at least 1 h or renal replacement therapy

  • Lactates > 4 mmol/L

  • Hypotension (SBP < 90)

  • Abrupt change in mental status or abnormal electroencephalogram

  • Platelet counts <100 000/mL or disseminated intravascular coagulation

  • Acute lung injury—acute respiratory distress syndrome

  • Cardiac dysfunction (echocardiography)

Septic Shock

Severe sepsis and 1 of the following:

  • Signs of organ damage.

  • Systemic mean blood pressure <60 mm Hg (<80 mm Hg if previous hypertension) after 20–30 mL/kg starch or 40–60 mL/kg serum saline, or pulmonary capillary wedge pressure between 12 and 20 mm Hg

  • Lactate > 2 mmol/L

  • Need for dopamine >5 μg · kg−1 · min−1 or norepinephrine or epinephrine <0.25 μg · kg−1 · min−1 to maintain mean blood pressure above 60 mm Hg (80 mm Hg if previous hypertension)

Analysis of SIRS, Sepsis, Severe Sepsis and Septic Shock using Tableau

First let's understand the dataset. In the dataset, we have patients who have sepsis (sepsis label=1), non sepsis patients (sepsis label=0) and onset patients who did not have sepsis when they were admitted in the hospital but developed later during their stay in hospital. The following chart shows the segregation of patients based on sepsis label

From the above visualisation, we can see that out of all the patients in the dataset, 92.73% of patients don't have sepsis and 7.27% of patients have sepsis. The main objective of this analysis is to find out the sepsis and non sepsis patients is to provide timely medications and diagnosis to them so that the non sepsis patients do not reach to sepsis stage and sepsis patients do not get severe sepsis or septic shock thereby reducing the mortality.

As SIRS is the previous stage of sepsis, so in our data we have 24,271 patients who have SIRS but no sepsis and 1825 patients who have SIRS and sepsis based on the above given conditions for SIRS. The following chart shows the patients and their biomarkers ( body temperature, heart rate, respiration rate, PaCO2, white blood cell ) value and the SIRS category shows which two biomarkers are abnormal.

Looking at this chart, the doctors can easily identify the patients who are at initial stage of sepsis and immediate treatment can be started . The below chart shows the hourly trend for SIRS biomarker values for all the patients. With the help of this chart doctors can monitor the patient's health hourly.

The following chart shows the patients who have sepsis and developed severe sepsis. The chart also shows which biomarkers are abnormal. This chart can provide the doctors with insight about which biomarkers are abnormal that caused the severe sepsis in patients. The different colors shows the different abnormal biomarkers (normal are shown in gray).

All these patients are at a risk of severe sepsis as they already have sepsis and SIRS. Among these patients following patients are at a very high risk of Septic Shock as most of the related biomarkers are abnormal.


  • SIRS - 2 YES answers meets criteria.

  • Sepsis Criteria - 2 YES of SIRS + Suspected Source of Infection.

  • Severe Sepsis Criteria - 2 YES of SIRS + Lactic Acidosis, SBP.

  • Septic Shock - 2 YES of SIRS + Evidence of ≥ 2 Organs Failing.


Intensive care units (ICU) in most settings consume very high cost and sophisticated devices but mortality rates are still very high. There has been a great advancement recently in developing various models to measure severity of critically ill patients and to predict their mortality. Several models like APACHE II, SAP and SOFA have been devised for mortality prediction in critical ill patients.

APACHE II (acute physiology and chronic health evaluation II) is commonly used scoring system for severity of illness in intensive care for the general ICU population and can predict the risk of in-hospital death. SOFA (sequential organ failure assessment) is another commonly used scoring system which is related to organ failure and used for prediction of outcome.


The Sequential Organ Failure Assessment (SOFA) score is a scoring system that assesses the performance of several organ systems in the body (neurologic, blood, liver, kidney, Respiratory and cardiovascular) and assigns a score based on the data obtained in each category. The higher the SOFA score, the higher the likely mortality. The SOFA score is composed of six variables - one for each organ system. They are graded from 0 to 4 according to the degree of dysfunction/failure of the relevant organ. You can find the scoring system and all variables in the table below.

SOFA Score





Central Nervous System


Pao2/FIO2, mmHg

Platelets x10^3/μL

Bilirubin, mg/dL


Glasgow Coma Scale

Creatinine, mg/dL or urine





No hypotension






1.2- 1.9

MAP < 70 mmHg







Dop<=5 or Dob (any dose)







Dop>5 or epi<=0.1, or norepi<=0.1$


3.5-4.9 or < 500





Dop>15 or epi>0.1, or norepi>0.1$


>5 or <200


  • & - values are with respiratory support;

  • $ - adrenergic agents administered for at least 1 hour (doses given are in μg/kg per minute);

  • FIO2 - fraction of inspired oxygen;

  • Norepi - norepinephrine;

  • Dob - dobutamine;

  • Dop - dopamine;

  • Epi - epinephrine.

The evaluation of the SOFA score throughout an ICU stay is a good prognostic indicator. However, independent of the initial score, an increase in the measured value during the first 48 hours of ICU admission indicates a mortality rate of at least 50%.

Analysis of SOFA SCORE Using the dataset

The chart shows the SOFA score and mortality percentage for all the patients based on the grade of six variables - PaCO2, FiO2, Bilirubin, Creatinine, MAP and Platelets, from 0 to 4 according to the degree of dysfunction/failure of the relevant organ. The chart also shows the mortality rate for each SOFA Score.


The Apache II Score estimates ICU mortality based on a number of laboratory values and patient signs taking both acute and chronic disease into account. The APACHE II score assess the severity of a disease and compute the intensive care unit (ICU) mortality rates for patients using their medical history, characteristics, physical examination, and laboratory test results. the APACHE II score is meant for people over 16 years of age.

The table below introduces the variables used and the number of points awarded to each of their intervals.

Analysis of APACHE II SCORE Using the dataset

The chart shows the APACHE Score for all the patients and mortality percentage based on the grade of variables from 0 to 8 according to the degree of dysfunction/failure of the relevant organ. The chart also show the mortality rate based on the APACHE Score.

Through the SOFA or APACHE Score , doctors can easily identify the severity of the patient's condition based on the score along with other factors discussed above for SIRS and Sepsis. Higher the score, the higher the severity of the patient’s condition. Both the SOFA and APACHE II score systems are crucial in assessing the prognosis of critically ill patients.


Septic shock is a severe medical condition. The survival rate is low, but people do survive. Survival depends on your age, health, cause of the condition, if you’ve had organ failure and how quickly you receive treatment. Without treatment, most people die of septic shock. With treatment, 30% to 40% of people with septic shock die.

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