الفهرس 
DEFINITIONS AND CLASSIFICATION OF SURGICAL SITE INFECTIONOnly 14 pages are availabe for public view
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Abstract
SSI is an infection that occurs somewhere in the operative field following a surgical Intervention. It accounts for 14% to 16% of hospital-acquired infections. Bacteria are responsible for the majority of surgical infections. A small number of gram-positive cocci and gram-negative bacilli are responsible for most SSIs.
All surgical wounds are likely to become contaminated, usually by resident bacterial flora from skin or viscera. This may not be of clinical significance and contaminated wounds may go unnoticed. However, progression from wound contamination to clinical infection is largely determined by the adequacy of host defense, the most important immune mechanism of which is neutrophil phagocytosis which occurs during a crucial few hours intraoperatively and after operation.
There are many risk factors incriminated in SSI, one of them is age as there is a direct linear trend of increasing risk of SSI until age 65 has been demonstrated. Underlying illness also plays a major role in SSI such as Diabetes which is considered the frequent cause, where there is a two to three fold increase in the risk of developing an SSI in patients with diabetes.
Anemia is a risk factor for the development of infection in surgical patients which have been demonstrated by several studies. On the other hand, some of those studies proved the association between transfusions and infections in patients undergoing different surgeries. Also it has been reported that malnourishment increased the incidence of SSI from 1.8% to 16.6%.
Treatments associated with anti-cancer therapy are indicators of SSI development. Also, it has been found that radiotherapy within 90 days prior to surgery and the use of steroids independently predicted development of SSI. Studies have repeatedly shown that obesity is strongly associated with an increased risk of SSI.
Smoking increases the risk of postoperative complication even in minor surgery. The wound healing process may be affected by the Vasoconstrictive effects and reduced oxygen carrying capacity of blood associated with smoking.
The control of SSI starts from basic measures and methods for prevention which are Cleaning (a process that removes foreign material as micro-organisms from an object), Disinfection (a process that reduces the number of pathogenic microorganisms) and Sterilization (a process that destroys all microorganisms including bacterial spores). Sterilization cannot be proved except by culturing, so normally an object is said to have been sterilized if it has gone through a controlled process of sterilization).
Other methods of prevention may include some preoperative methods which are preparation of the patient which include appropriate preoperative hair removal, Preoperative antiseptic showering , Controlling blood glucose level, Smoking cessation, treatment of remote infections, Preparation of the surgical team which includes Hand/forearm antisepsis for surgical personnel, management of infected or colonized surgical personnel, An operating room environment which include Cleaning and disinfection of environmental surfaces, sterilization of surgical instruments, ventilation of the operating room.
The anesthesiologist plays a major role in prevention of SSI begins with the administration of appropriate antimicrobial prophylaxis. The goal of perioperative antibiotic administration is to obtain blood and tissue drug levels that exceed the minimum inhibitory concentration of the organisms likely to be encountered.
Hyperglycemia in perioperative patients has been identified as a risk factor for morbidity and mortality. Intensive insulin therapy (IIT) by the anesthesiologist has been shown to reduce morbidity and mortality among the critically ill, decrease infection rates and improve survival after surgery.
Mild perioperative hypothermia (core body temperature 34°–36°C) is commonly observed in surgical patients. The complications of mild perioperative hypothermia have been studied extensively and include increased duration of hospitalization. Avoiding intraoperative hypothermia by the anesthesiologist helps to maintain tissue perfusion, reduces SSI, and shortens hospitalization.
The importance of high tissue oxygen levels in improved surgical outcomes and reduced surgical infection rates has been understood for many years. High tissue oxygen concentrations enhance the effects of leukocytes and antibiotics on microbes and are indicative of adequate tissue perfusion. Oxygen delivery to the tissues has been the target of many of the non pharmacologic strategies to prevent surgical wound infection.
Intra-operative fluid management by the anesthesiologist was thought to improve outcomes by improving perfusion, yet more recent data suggest that tissue edema from overly aggressive hydration may be detrimental. We remain on the optimal volume replacement strategy for optimal surgical outcomes.
There are strong relations between allogenic blood transfusion (ABT) and postoperative infection, postoperative mechanical ventilation, length of hospital stay, and mortality. So the anesthesiologist plays an important role in prevention of SSI by controlling (ABT).
Finally, it has been proposed that neuraxial anesthesia may diminish the risk of SSI. Previous studies have proved that epidural and spinal anesthesia is associated with lower incidence of SSI than general anesthesia in major surgeries.