Nov 30, 20222 min read

ABG Analysis in Sepsis Patients Using Gantt Chart In Tableau: Step by Step Process

Let's not be intimidated with the title! Firstly, let's understand the terminologies before diving in the methodology.

Sepsis

It a life-threatening condition caused by the body’s response to infection, which can lead to tissue damage, organ failure, amputations and death. It affects 1.7 million people in the United States each year.

ABG Analysis

ABG stands for Arterial Blood Gases. It involves the measurement of blood pH, carbon dioxide (CO2) and level of oxygen in the blood. The blood sample is taken from the artery and the measurements are performed.

Normal Values:

pH -- 7.35 -7.45

PaCo2 -- 35 -45 mm Hg

HCO3 -- 22-26 mEq/L

Metabolic Acidosis: When the pH and HCO3 are below the normal range and PaCO2 is normal, it is called Metabolic Acidosis.

Metabolic Alkalosis: When the pH and HCO3 are above the normal range and PaCO2 is normal, it is called Metabolic Alkalosis.

Respiratory Acidosis: When the pH is below the normal range, PaCO2 is above the normal range and HCO3 is normal, it is called Respiratory Acidosis.

Respiratory Alkalosis: When the pH is above the normal range, PaCO2 is below the normal range and HCO3 is normal, it is called Respiratory Alkalosis.

Gantt Charts

Gantt charts are primarily used in project management to visualize time duration for events or activities. However, we will be using them to display the patients with the abnormalities in the ABG analysis along with the measurement values for the bio parameters.

Step By Step Process:

Step 1:

Creation of calculated field called 'Axis'. Write the number 0 in the formula field and click OK.

Step 2:

Drag Axis from the Data Pane to the columns . Next, drag pH also to the columns.

Step 3:

Using the drop down menu, select Dimension for both Axis and pH

Step 4:

From the drop down menu in pH, choose Dual Axis

Step 5:

Repeat Step 2-4 for the other two biomarkers - PaCO2 and HCO3.

Step 6:

Drag Patient ID from the data pane to the columns. Click on ' Add All Members'

Step 7:

Create the following calculated fields:

Metabolic Alkalosis

Metabolic Acidosis

Respiratory Acidosis

Respiratory Alkalosis

Step 8:

Under Marks, drag pH, PaCo2 and HCO3 to their respective Texts

Step 9:

Under the marks, in Axis 1, 2 and 3, make the opacity of 'Colors' to 0% and the 'Size' to 0

Step 10:

Drag the respective calculated fields (Metabolic Acidosis/Metabolic Alkalosis/Respiratory Acidosis/Respiratory Alkalosis) to filter and select the non-null values.

The Gantt chart is ready displaying all the sepsis patients with their respective values for pH, PaCO2 and HCO3. It visualizes the value of each biomarker .