2nd August 2023

Sepsis

Definition

Sepsis can be defined as a dysregulated response to severe infection resulting in life-threatening organ dysfunction. Sepsis starts from a local site of infection and results from the bacteria spreading into the bloodstream resulting in a systemic response. End organ dysfunction in sepsis can be defined using the Sequential (or Sepsis-related) Organ Failure Assessment (SOFA) criteria which scores patients on parameters of respiratory function, cardiovascular system, liver dysfunction, renal dysfunction, coagulation, and neurology (based on their GCS).

Septic shock is an important ‘not to be missed’ sequelae of sepsis and can be defined as the co-existence of persistent hypotension requiring vasopressors to maintain a mean arterial pressure ≥65mmHg and a serum lactate of >2mmol/L. Septic shock presents a much greater risk of mortality and is associated with the risk of circulatory, cellular, and metabolic deterioration.

Causes

Sepsis can be the result of both primary infection and because of secondary clinical interventions. Certain conditions and situations can put patients at higher risk of developing sepsis. Examples of these are:

• Patients <1 or >75 years of age
• Patients who have impaired immune systems
  • Chemotherapy for cancer patients
  • Impaired immune function (e.g. diabetes, sickle cell, splenectomy)
  • Long term steroids
  • Immunosuppressant drugs
• Surgery of invasive procedures in past 6 weeks
• Skin breaks
  • Cuts
  • Burns
  • Skin infections
• IV drug use
• Indwelling lines or catheters
• Women who are pregnant, have given birth or termination of pregnancy or miscarriage in the last 6 weeks. Higher risk for those who:
  • Have an impaired immune system
  • Gestational diabetes or diabetes
  • Needed invasive procedures (e.g. caesarean or forceps, removal of retained products)
  • Prolonged rupture of membranes
  • Have been in close contact with people with group A streptococcal infection
  • Continued vaginal bleeding or offensive discharge

When looking for the causes of sepsis, it is important to consider all body systems and to ensure the patient is fully examined and exposed to try and identify the source.

Common sites of infection include the lungs, for example, community acquired pneumonia, the urinary tract, and the abdomen, for example, abdominal abscesses or perforation.

Clinical Features

Sepsis is the result of bacteraemia and severe infection. There are several clinical features, and people can present in different ways. However, typically patients will have a high or low temperature, raised inflammatory markers, low BP, and high HR. In addition, patients often have a wide pulse pressure. Parameters such as hypothermia or neutropenia can indicate a more severe infection.

In addition to abnormal observations and systemic features causing sepsis, it is important to consider localising symptoms which can point to the source of the original infection.

Assessment

It is important to recognise sepsis early as it can lead to end organ damage, septic shock and death if not treated rapidly. History and examination remain key – make sure to obtain a collateral history if the patient cannot, e.g., altered mental state. Important questions include recent fevers, specific infective symptoms, such as dysuria or productive cough, clinical features suggesting dehydration, altered behaviour or mental state, sudden deterioration in functional ability and risk factors for sepsis.

Adopt an A-E approach utilising information from a patient’s National Early Warning Score (NEWS2) – this comprises 6 parameters: respiration rate, oxygen saturations, systolic blood pressure, pulse rate, level of consciousness or new-onset confusion and temperature. Each parameter is scored from 0-3. This score is then combined to give a total score indicating risk; low (1-4), low to medium (a score of 3 in any single parameter), medium (5-6) and high risk (≥8). This score can help provide an early indication that a patient is becoming unwell and possibly septic. It can identify parameters that may need urgent correction, such as hypoxia or hypotension, as well as thoroughly assessing and exposing the patient to look for an original source of infection to provide the correct antibiotic treatment.

As per recent NICE guidelines, patients should also be risk stratified according to their examination findings and assessed for the severity of their illness, risk of clinical deterioration and risk of death from sepsis (table 2).

Table 2: Risk stratification tool for patients with sepsis

National Institute for Clinical Excellence (2017) Sepsis: recognition, diagnosis, and early management. Available at: https://www.nice.org.uk/guidance/ng51 (Accessed: 16 March 2022).

Investigation and Management

The UK Sepsis Trust ‘Sepsis Six’ bundle, which should be given within the first hour of identifying sepsis.

• ‘3 in’ –intravenous fluids, broad spectrum antibiotics and oxygen therapy (if required)
• ‘3 out’ –blood cultures (2 sets), serum lactate measurement and urine output

If patients are critically unwell, a discussion with intensive care may be required to consider central venous access, inotropes, or vasopressors.

• Inotropes: medications which can increase cardiac output by increasing cardiac contractility
• Vasopressors: increase blood pressure by increasing peripheral vascular resistance

These may be required to maintain perfusion pressure in patients with severely deranged observations and parameters, those in the high-risk criteria (table 2), and those not responding to initial treatments.