HHE Emergency care supplement 2018 - Page 14

emergency and critical care Recent developments in surgical sepsis Every surgical operation is an experiment in bacteriology – Moynihan Ramya Kalaiselvan MBBS MPhil FRCS Gordon Carlson BSc(Hons) MB ChB (Hons) MD FRCS FRCSGen FRCSEd (Ad Hom) Department of General and Colorectal Surgery, Salford Royal NHS Foundation Trust, Manchester, UK It is almost a century since Moynihan famously noted that, “every surgical operation is an experiment in bacteriology.” 1 While the basic components of that experiment (the host, the bacterial flora and the factors which alter the balance between bacterial capacity for invasion and host resistance) have not changed, the outcome of surgical procedure, even when complicated by infection, has improved markedly. The last century has seen overwhelming advances in reducing the incidence of surgical (and other) infections, as well as an ability to treat them more effectively. These have resulted from (inter alia), better nutrition and overall public health, a better understanding of factors which contribute to infection such as temperature maintenance, oxygenation, blood glucose control, and aseptic technique, and of course the development of powerful antibiotics for both prophylaxis and treatment of infection complicating surgical care. However, despite these measures, infection remains a common and life-threatening problem and the sepsis, which results from this infection, continues to be a significant cause of avoidable mortality, morbidity and health expenditure. Some of the most devastating adverse consequences of infection result not from the direct pathogenic effects of the invading bacteria but from the immunological consequences of the host response. While a coordinated pro- and anti-inflammatory response is essential for localisation, bacterial killing, and resolution, infection can trigger an overwhelming host inflammatory response, resulting in shock, multi-organ dysfunction, and death. The definitions of sepsis, septic shock, and organ dysfunction were based on an international consensus conference, 2 which focused on the then-prevalent view that sepsis developed as part of a host systemic inflammatory response syndrome (SIRS), triggered by an infectious insult, noting that sepsis could arise in response to multiple infectious causes and that ‘septicaemia’ was neither a necessary condition nor a helpful term. It was proposed that sepsis complicated by organ dysfunction was termed severe sepsis, which could progress to septic shock, defined as “sepsis-induced hypotension”, persisting despite adequate fluid resuscitation or by hyperlactataemia. In 2001, a second consensus panel endorsed most of these concepts, with the caveat that signs of a systemic inflammatory response, notably tachycardia or an elevated 14 HHE 2018 | hospitalhealthcare.com white-cell count, also occur in many non- infectious conditions and therefore are not helpful in distinguishing sepsis from other conditions. 3 In addition, severe sepsis and sepsis were sometimes used interchangeably to describe the syndrome of infection complicated by acute organ dysfunction. Attempts to take account of the fact that critical illness might arise as a consequence of infection, without the requirement for the patient necessarily to exhibit the fever, tachypnoea, tachycardia and leukocytosis required of SIRS led to a third International consensus for sepsis and septic shock, at which sepsis was defined as life- threatening organ dysfunction caused by a dysregulated host response to infection. 4 This new definition also recommended using