How Is Sepsis Diagnosed?

Since the signs and symptoms of sepsis can be due to other illnesses, diagnosing sepsis can sometimes be hard. A number of tests are done to identify the main infection that causes sepsis.

Blood Tests

Blood samples can be taken from two different parts of the body to detect the presence of the following:

• infection (bacterial, viral, or fungal)
• blood clotting factors
• normal functioning of the liver and kidneys
• reduced oxygen levels
• imbalanced electrolytes

Doctors usually request laboratory tests to help them diagnose the disease, differentiate diseases from other conditions, as well as to further assess and monitor the patient’s organ-system function, oxygenation of blood, and blood pH (acid-base balance).

Laboratory tests include:

• Culture test – to identify the specific type of bacteria that is present in the blood and test its antibiotic susceptibility.
• Urine culture and cultures of other body fluids – to determine the main source of infection, leading to an accurate diagnosis of the disease.
• Procalcitonin or PCT test – is ordered for the early detection of sepsis. Sometimes, the test is used to identify sepsis from other diseases, which show similar signs and symptoms. Procalcitonin is a protein that significantly increases when an individual has sepsis.
• Complete blood count (CBC) – is one of the most common laboratory tests performed for the evaluation of several elements in the blood such as red blood cells (RBCs), white blood cells (WBCs), and platelets.
• Lactate – increased levels of lactate can indicate an organ dysfunction.
• Blood gases – to evaluate the level of oxygen in the blood and acid-base balance.
• Metabolic tests – these tests are conducted to effectively monitor the status of the body’s organs such as the liver and kidneys. Metabolic tests also check electrolyte imbalances and levels of glucose in the blood.
• Other clotting tests - to check the clotting ability of your blood.
• Protein tests – to detect if any inflammation is present in the body.

You may also be tested on the following body secretions according to the severity of your condition:

• Wound secretions - secretions from a wound that seems infected are sampled and tested to determine what antibiotic would best suit for the treatment of the infection.
• Urine - your urine may be tested for signs of bacterial infection if the doctor thinks you have an infection in the urinary tract.
• Respiratory secretions - sputum from your cough or mucus from your nose may be tested to know the cause of the infection.

Use of Imaging Scans

One or more of the following scans may be conducted if the cause of the infection is yet not clear:

• X-ray - this type of scan uses low radiation levels. X-rays are used to visualize any complications in the lungs.
• CT scan - this type of scan easily detects infections in the pancreas, bowels, or the appendix. In a CT scan, X-rays are taken from different angles and put together to show cross-sectional parts of your internal body.
• Ultrasound - sound waves are used to create real-time pictures on a video monitor. It is effective in detecting gallbladder and ovarian infections.
• MRI (Magnetic Resonance Imaging) - an MRI is effective in detecting infections of the soft tissues such as a spinal abscess. Radio waves and strong magnets are used in this scan to create cross-sectional pictures of the internal parts of the body.

Sepsis Treatments

All sepsis patients are required for hospital admission to treat them with appropriate IV antibiotics and therapy for their malfunctioning organs. Organ damage and even death can take place very fast in sepsis patients. The rate of mortality goes up by 7 percent in an hour when treatment is delayed. To avoid further complications, treatment should be not delayed. The majority of sepsis patients are treated in the intensive care unit (ICU) of the hospital.

A combination of two or three antibiotics is administered to effectively treat sepsis. Vancomycin is contained in the majority of these combinations to treat methicillin-resistant Staphylococcus aureus (MRSA) infections. 

The patient is given more specific antibiotics once the cause of the infection is detected. An organ-system support and surgery may be required in addition to antibiotics to assist the lungs to function properly, dialysis for the kidneys, a central venous catheter (CVC) for the administration of other types of medicine, and IV fluids to replace lost body fluids. Antihypertensive medication is also given through IV to increase the blood pressure. The patient may also require surgery to drain or eliminate the source of infection. In worst cases, amputation of the extremities can also be done.

Who treats sepsis?

In most cases, the first specialists to treat a sepsis patient are the patient’s primary care physician, pediatrician (for children), or a specialist in emergency medicine. All sepsis patients should be treated in the hospital since there are no home remedies for the treatment of the disease. The following types of doctors may be consulted depending on the severity of the infection that leads to sepsis:

• intensivists (critical care specialists)
• hospitalists
• pulmonologists
• infectious disease (ID) specialists
• toxicologists

Different Tests to Confirm Sepsis

Procalcitonin (PCT)

Procalcitonin or PCT is generally considered as the most sensitive biomarker for infections, sepsis, and other diseases with severe systemic inflammation. PCT results can aid emergency physicians and critical care specialists in diagnosing sepsis.

Procalcitonin is a type of protein that comprises 116 amino acids. It is mainly produced by parafollicular cells or C cells in the thyroid gland. A very low level of this amino acid is normally present in the blood. However, an increased in the production of PCT can be due to cytokine stimulation and bacterial toxins. In other words, a larger amount of this amino acid is released when there is an infection, especially in a systemic bacterial infection such as sepsis.

The levels of PCT in the blood are used to detect any inflammatory responses, thereby making it a good risk indicator for sepsis. High levels of PCT usually indicate that there is a systemic infection or sepsis. In such cases, even though sepsis is not yet confirmed, treatment using antibiotics are administered after blood tests are performed for the early detection of any bloodborne pathogens. For this reason, performing a blood culture is necessary. However, a blood culture is a time-consuming process, which usually takes several days to complete. Moreover, the test does not often signify if there is systemic inflammation or an organ failure.

Immunoassay Analyzers

Immunoassay analyzers are developed, which serve as an easy-to-use PCT test for the diagnosis of sepsis. The analyzers provide test results within 21 minutes.

Cerebrospinal Fluid (CSF) Test

In addition to the tests listed above, a cerebrospinal fluid (CSF) test is also conducted to rule out meningitis. Other tests may be done to help evaluate the patient's health status or to identify or rule out complications of other conditions, such as cardiac biomarkers to detect heart problems.

A few non-laboratory tests can also be done to detect other complications. The patient is given specific treatments once the results are analyzed and a diagnosis is confirmed.