Page 107 Complete Your CE Test Online - Click Here Nursing consideration: Nurses can go to SiteCollectionDocuments/SSCBundleCard_Web.pdf to print out bundle badge cards for quick and easy reference of bundle recommendations. Self-evaluation: Question 5 Which of the following is part of the 3-hour bundle that should be completed within the first 3 hours of presentation of sepsis? a. Ensure airway and oxygenation. b. Measure lactate levels. c. Perform diagnostic imaging to determine source of infection. d. Secure venous access. CAUSATIVE AGENTS The causative agents behind sepsis are numerous and include bacterial, fungal, and viral agents and parasites. However, bacterial agents that induce infection are the most common culprit (Neviere, 2017). In almost half of all reported cases of sepsis, a pathogen is not identified (Gupta et al., 2016). Respiratory infections, such as pneumonia, are the most frequent cause of sepsis and septic shock, followed by intraabdominal infections, urinary tract infections, and primary bloodstream infections (Artero et al., 2012). Respiratory and abdominal infections have a poorer prognosis than sepsis that is caused by other factors (Artero et al., 2012). When sepsis is caused by gram-negative bacteria, the outer membrane component that triggers sepsis can be an endotoxin, lipopolysaccharide, or lipid A (LaRosa, 2010). Escherichia coli, salmonella, shigella, pseudomonas, acinetobacter, neisseria, haemophilus influenza, and vibrio cholera are types of gram-negative bacteria. Gram-positive bacteria include staphylococcus, streptococcus, and enterococcus. Gram-positive bacteria produce exotoxins, which are much more potent than the endotoxins produced by gram-negative bacteria and can be implicated in toxic shock syndrome caused by staphylococcus aureus or streptococcus pyogenes (Cohen, 2012). These bacteria cause T cell activation and trigger the release of proinflammatory lymphokines (Cohen, 2012). Toxic shock syndrome can affect otherwise healthy people. Mortality rates can be as high as 50% (Cohen, 2012). Gram-negative bacteria were historically noted as the most common type of bacteria associated with the development of sepsis. However, gram-positive bacterial infections are increasing in incidence, and studies have shown gram-positive bacteria to be an even greater source for sepsis than gram-negative bacteria are (Martin, Mannino, Eaton, & Moss, 2003). The most common organisms that lead to the development of sepsis are staphylococcus aureus, pseudomonas, enterobacteriaceae (escherichia coli is the most common of this species), fungi, and Acinetobacter (Mayr, Yende, Angus, 2014). In addition, the incidence of multiresistant bacteria (multiresistant pseudomonas, methicillin- resistant staphylococcus) has increased significantly over recent years (Artero et al., 2012). Nurses may have the opportunity to review the culture reports on patients long before the clinician and are, therefore, in a position to recognize the reports that need immediate reporting. Starting the correct antibiotic may be instrumental in avoiding septic shock. Table 1. Frequency of pathogens associated with the development of sepsis Gram Positive Gram Negative Viruses Fungus Parasites Methicillin-susceptible Staphylococcus: 14%–24% Escherichia coli: 9%–27% 2%–4% Candida albicans: 1%–3% 1%–3% Methicillin-resistant Staphylococcus: 5%–11% Pseudomonas aeruginosa: 8%–15% Streptococcus pneumoniae: 9%–12% Klebsiella pneumoniae: 2%–7% Enterococcus: 3%–13% Haemophilus influenzae: 2%–10% Annane et al., 2005 Viral infections Viral infections include influenza, parainfluenza, meningitis, pneumonia, respiratory syncytial virus, HIV, herpes, Epstein-Barr virus, Cytomegalovirus, and Adenovirus (Pomerantz & Weiss, 2016; Sepsis Alliance, n.d.). Viral infections can cause sepsis directly or ultimately lead to the development of a bacterial infection (e.g., a person starts with influenza that leads to the development of a bacterial pneumonia). Sepsis from a viral infection can occur in patients with compromised immune function and who are highly susceptible to opportunistic pathogens. Fungal infections The incidence of fungal infections as a cause for the development of sepsis has increased greatly in recent years (Martin et al., 2003). The reason for this increase could be better management and treatment of bacterial infections or a rise in nosocomial-associated fungal infections (Martin, 2012). Invasive fungal infections, usually caused by Candida albicans, are seen with more frequency in critically ill patients, accounting for 10% to 15% of all health care-associated infections (Delaloye & Calandra, 2014). Fungal infections are responsible for 5% of all sepsis and septic shock cases and are the fourth most common organism found in positive blood cultures in the United States (Delaloye & Calandra, 2014). Candida is a normally found in the skin, vagina, and GI tract and does not typically cause a problem for people with an intact and healthy immune system. The risk of developing an infection from a fungus like Candida increases with the following factors (Delaloye & Calandra, 2014): ● ● Patient age. ● ● Broad-spectrum antibiotic use. ● ● Length of hospital stay. ● ● Central vascular catheter placement. ● ● Diabetes mellitus. ● ● Parenteral nutrition. ● ● Mechanical ventilation. ● ● Renal insufficiency or hemodialysis. ● ● Antifungal prophylaxis. ● ● Surgery. ● ● Pancreatitis. ● ● Treatment with corticosteroids and chemotherapy. Parasitic infections Parasitic causes of sepsis are rare, especially in North America, but they occur in other parts of the world. In the case of sepsis caused by malaria, for example, a parasite infects a mosquito and the mosquito, in turn, infects a person. Key points ● ● Sepsis can be caused by bacterial, viral, fungal, or parasitic organisms. ● ● Bacterial agents are the most common cause of infection that leads to sepsis, specifically gram-positive bacteria. ● ● Respiratory infections, such as pneumonia, are the most frequent cause of sepsis and septic shock, followed by intraabdominal infections, urinary tract infections, and bloodstream infections. ● ● The incidence of sepsis caused by multiresistant bacteria and fungal infections has risen in recent years.