Sepsis

What is sepsis? Sepsis was defined in a 1992 consensus definitions conference as a systemic response to new infection. This is known as SIRS – systemic inflammatory response syndrome

Prevalence and incidence Worldwide sepsis kills over 1400 people a day In the UK over 37,000 people die from sepsis annually Each episode of sepsis costs the NHS £20,000 More people die from sepsis each year than the following combined: Lung Cancer Breast Cancer Bowel Cancer

Types of Sepsis Sepsis – Systemic inflammatory response syndrome resulting from a presumed or known site of infection Sever Sepsis – Sepsis with an acute associated organ failure Septic Shock – A subset of sever sepsis, defined as a persistently low mean arterial blood pressure despite adequate fluid resuscitation Refractory Shock – Persistently low mean arterial blood pressure despite vasopressor therapy and adequate fluid resuscitation

Pathophysiology Can occur as a result of infection at any body site, the most common pathogen is bacteria but it can be caused by fungi, viruses or parasites as well Characterized by simultaneous activation of inflammation and coagulation Cytokines and white blood cells trigger vasodilation to increase capillary permeability, neutrophil activation and adhesion of platelets to the endothelium Baroreceptors in the carotid arteries and aorta respond to a drop in the patient’s blood pressure and activate the sympathetic nervous system

Pathophysiology continued Vasoconstrictors Epinephrine Norepinephrine… are all released to maintain blood flow to vital organs (the heart and brain) Blood is shunted from the non – vital organs Eventually affects: Cardiac output Circulating volume Blood Pressure = Multiple Organ Dysfunction Syndrome (MODS) = Death

Defining Sepsis Systemic Inflammatory Response Syndrome (SIRS) is defined by the presence of two or more of the following symptons: Temperature <36°C or >38°C Heart rate >90 beats per minute Respiratory rate >20 beats per minute White blood count <4,000 per ml or >12,000 - Levy et al, 2003

Patients at a higher risk of Sepsis People <1 year and >65 years Those with a chronic illness People who are immunosuppressed Those who are on a broad – spectrum antibiotic use Exposure to infection associated with surgical and invasive procedures N.B. >65 years is due to a decline in immune function

Severe Sepsis Sepsis complicated by organ dysfunction Sepsis – induced hypotension Most patients who acquire severe sepsis do so on the first day of a hospital stay Hypoperfusion abnormalities such as: Lactic acidosis, oliguria, acute alteration of mental state Mortality rate of 35%, 7 times higher than that of Acute Coronary Syndrome

Septic Shock The presence of sepsis and a state of acute circulatory failure, characterized by refractory arterial hypotension(<90mm Hg) – not explainable by other causes Evidence of hypoperfusion (high lactate) The patient is dependent on vasopressors at this point Transition from severe sepsis to septic shock normally happens within 24 hours of hospitalization Mortality rate approaching 50% Will be likely to require invasive monitoring such as venous catheters and vaso – active drug infusions

Diagnosis Difficult to do – first six hours are very important as this is the time when tissue hypoxia can be reversed Early organ dysfunction is normally the first notable find Other diagnostic criteria: Hemodynamic instability Arterial hypoxemia Oliguria Coagulopathy Altered liver function tests Serum lactate level is a diagnostic marker – lactate is generated by anaerobic cellular metabolism and may reflect the severity of cellular derangements

Treatment Often focused on supporting failing organ systems with interventions: Fluid replacement – for restoration of tissue perfusion and normalization of oxidative metabolism Airway management – for patients with progressive hypoxemia, hypercapnia, neurologic deterioration or respiratory muscle failure Antibiotic Therapy Vasopressors – when fluid administration fails to restore an adequate arterial pressure and organ perfusion Need to increase cardiac output For every hour’s delay in beginning treatment, a patient’s risk of death increases by 7.6% (Kumar et al, 2006)

Sepsis Six An operation pathway which comprises tasks which can be completed immediately in a ward or A & E When given within 1 hour of Sepsis being recognised, the Sepsis Six pathway is proven to save lives. The steps: Give high flow oxygen (via non – rebreathe bag) Take blood cultures Give IV antibiotics Start IV fluid resuscitation (Hartmann’s or equivalent) Check haemoglobin and lactate Monitor accurate hourly urine output (may require a catheter) - Surviving Sepsis Campaign

Surviving Sepsis Campaign Main aims were to improve the management, diagnosis and treatment of sepsis How this is being achieved: Increasing awareness, understanding and knowledge Changing perceptions and behaviour Influencing public policy Defining standards of care Through the campaign it was determined that the greatest achievement was through education and changing the process of care which patients with sepsis received