Transferrin plays a role in host defense by:
Once microbes enter a sterile body compartment (eg, pleural or peritoneal cavity) or tissue, additional host defenses act to limit and/or eliminate these pathogens. Initially, several primitive and relatively nonspecific host defenses act to contain the nidus of infection, which may include microbes as well as debris, devitalized tissue, and foreign bodies, depending on the nature of the injury. These defenses include the physical barrier of the tissue itself, as well as the capacity of proteins, such as lactoferrin and transferrin, to sequester the critical microbial growth factor iron, thereby limiting microbial growth. In addition, fibrinogen within the inflammatory fluid has the ability to trap large numbers of microbes during the process in which it polymerizes into fibrin. Within the peritoneal cavity, unique host defenses exist, including a diaphragmatic pumping mechanism whereby particles including microbes within peritoneal fluid are expunged from the abdominal cavity via specialized structures on the undersurface of the diaphragm. Concurrently, containment by the omentum, the so-called "gatekeeper" of the abdomen and intestinal ileus, serves to wall off infection. However, the latter processes and fibrin trapping have a high likelihood of contributing to the formation of an intra-abdominal abscess.
Which is NOT a component of systemic inflammatory response syndrome (SIRS)?
Infection is defined by the presence of microorganisms in host tissue or the bloodstream. At the site of infection the classic findings of rubor, calor, and dolor in areas such as the skin or subcutaneous tissue are common. Most infections in normal individuals with intact host defenses are associated with these local manifestations, plus systemic manifestations such as elevated temperature, elevated white blood cell (WBC) count, tachycardia, or tachypnea. The systemic manifestations noted above comprise the systemic inflammatory response syndrome (SIRS).
The best method for hair removal from an operative field is:
Hair removal should take place using a clipper rather than a razor; the latter promotes overgrowth of skin microbes in small nicks and cuts. Dedicated use of these modalities clearly has been shown to diminish the quantity of skin microflora.
A patient with necrotizing pancreatitis undergoes computed tomography (CT)-guided aspiration, which results in growth of Escherichia coli on culture. The most appropriate treatment is:
The primary precept of surgical infectious disease therapy consists of drainage of all purulent material, debridement of all infected, devitalized tissue, and debris, and/or removal of foreign bodies at the site of infection, plus remediation of the underlying cause of infection. A discrete, walled-off purulent fluid collection (ie, an abscess) requires drainage via percutaneous drain insertion or an operative approach in which incision and drainage take place. An ongoing source of contamination (eg, bowel perforation) or the presence of an aggressive, rapidly spreading infection ( eg, necrotizing soft tissue infection) invariably requires expedient, aggressive operative intervention, both to remove contaminated material and infected tissue (eg, radical debridement or amputation) and to remove the initial cause of infection (eg, bowel resection).
Which factor does NOT influence the development of surgical site infections ( SSIs)?
Surgical site infections (SSis) are infections of the tissues, organs, or spaces exposed by surgeons during performance of an invasive procedure. SSis are classified into incisional and organ/space infections, and the former are further subclassified into superficial (limited to skin and subcutaneous tissue) and deep incisional categories. The development of SSis is related to three factors: (1) the degree of microbial contamination of the wound during surgery, (2) the duration of the procedure, and ( 3) host factors such as diabetes, malnutrition, obesity, immune suppression, and a number of other underlying disease states.
Click to expand