Severe sepsis affects approximately 26 million patients globally each year. Approximately 1/3 of these patients die, making sepsis one of the most important causes of death worldwide.
The definition of sepsis was changed in 2016. Sepsis is now defined as life threatening organ dysfunction resulting from a dysregulated host response to infection. (In other words, a severely ill patient with infection). This is similar to what was previously defined as severe sepsis. Systemic signs of infection include tachycardia, tachypnoea, fever or hypothermia and leucocytosis or leucopaenia. Not all of these need be present and an infected patient may not be febrile nor have a leucocytosis. As a result, sepsis should be considered in all critically ill patients who do not have an obvious cause for organ failure. This includes GI failure (diarrhoea and vomiting).
It is also important to realize that not all patients with these signs are infected – some will have a non-infectious cause for systemic inflammation (eg trauma, haemorrhage, pancreatitis).
Sepsis is one of the two commonest causes of shock.
The key elements in the management of sepsis are:
Sepsis is a very common cause of critical illness and should be considered in all patients with acute organ dysfunction. It is particularly important to recognize that altered mental status such as agitation, confusion and delirium may be due to sepsis and that sepsis is one of the two most common causes of shock.
The key is to ensure adequate oxygen delivery to tissues:
Choice of appropriate antibiotics depends on:
It is important therefore to take a history and examine the patient to determine the likely site of infection, focusing on the most common sites of infection:
The initial choice of antibiotics should cover all likely organisms and reflect local resistance patterns, which vary from country to country, hospital to hospital and ward to ward. It is therefore important to follow local guidelines. In the absence of these, the antibiotic regimes given in Neurological emergencies and Pneumonia may be useful.
Although microbiological results are not used to guide initial antibiotic therapy it is important to take appropriate specimens before starting antibiotics provided this does not result in undue delay of administration of antibiotics. Antibiotics should be given within 1 hour of the diagnosis of severe sepsis and should be given intravenously. The results from these specimens can be used to guide subsequent antibiotic therapy. In general 7 day courses of antibiotics are sufficient.
Microbiological specimens should include 2 sets of blood cultures before antibiotics and 1-2 sets more in the first 24 hours. These should be taken aseptically and at least 10 ml of blood should be inoculated into each bottle.
Urine should be sent for microscopy and culture. Respiratory secretions should be cultured if the clinical features suggest chest infection or the chest X-ray shows infiltrates. Specimens from other sites should be sent if clinical signs or investigations suggest infection at these sites. Specimens should be transported to the laboratory rapidly to minimize the chance of fastidious organisms dying before they can be transferred to culture media.
Every patient with sepsis should be assessed for a site of infection that is amenable to drainage (abscess), debridement (dead tissue) or removal (artificial device) and definitive control of the source of contamination (eg perforated bowel). Source control should be carried out as soon as possible after initial resuscitation and within 6 hours at the latest.
In general use the method of source control that causes the least physiological disturbance. For example, percutaneous drainage of an abscess is preferable to open surgical drainage, if feasible.
The key to management of sepsis is early recognition and early, aggressive treatment. This requires all tasks to be carried out urgently and efficiently by those seeing the patients. Tasks such as taking blood cultures should not be delegated to staff who are not present (eg phlebotomists) as this will lead to delayed administration of antibiotics or failure to take cultures before antibiotics are given. Delays of as little as one hour can result in a substantial increase in mortality.