Septic Shock

Medical Careers Institute
NUR 255
November 19, 2014
Instructor Y. Rogers

Introduction
Septic shock is the most common type of circulatory shock. Sepsis or septic shock is systemic inflammatory response syndrome (SIRS) secondary to a documented infection. This response is a state of acute circulatory failure characterized by persistent arterial hypotension despite adequate fluid resuscitation or by tissue hypoperfusion (manifested by a lactate concentration >4 mg/dL) unexplained by other causes. Sepsis can occur in stages that may progress from uncomplicated sepsis, to severe sepsis, to shock. Despite efforts to decrease shock with the use of antibiotics, the incidences continue. Septic shock is the leading cause of death in noncoronary ICU patients. More than 18 million cases of severe sepsis occur each year, this results in 1,400 deaths worldwide every day (Hinkle, 2014).
Background
In the past, the terms sepsis and septicemia have referred to several ill-defined clinical conditions present in a patient with bacteremia. These 2 terms have often been used interchangeably; however, only about half of patients with signs and symptoms of sepsis have positive results on blood culture. Serious bacterial infections at any site in the body, with or without bacteremia, are usually associated with important changes in the function of every organ system in the body. These changes are mediated mostly by elements of the host immune system against infection. Shock is deemed present when volume replacement fails to increase blood pressure to acceptable levels and when associated clinical evidence indicates inadequate perfusion of major organ systems, with progressive failure of organ system functions. Shock is identified in most patients by hypotension and inadequate organ perfusion, which may be caused by either low cardiac output or low systemic vascular resistance.
Pathophysiology
The pathophysiology of septic shock is not precisely understood but is considered to involve a complex interaction between the pathogen and the host’s immune system. Gram- negative bacteria are the most commonly implicated microorganisms in septic shock. The normal physiologic response to localized infection includes activation of host defense mechanisms that result in the influx of activated neutrophils and monocytes, release of inflammatory mediators, local vasodilation, increased endothelial permeability, and activation of coagulation pathways. These response mechanisms occur during septic shock, but on a systemic scale, leading to diffuse endothelial disruption, vascular permeability, vasodilation, and thrombosis of end-organ capillaries. Endothelial damage itself can further activate inflammatory and coagulation cascades, creating, in effect, a positive feedback loop and leading to further endothelial and end-organ damage.
Diagnostic Procedures To diagnose septic shock there are a couple of different test that must be done. First blood tests are done to check for infection around the body, low blood oxygen level, disturbances in the body's acid-base balance, and poor organ function or organ failure. Other tests may include a chest x-ray to look for pneumonia or fluid in the lungs (pulmonary edema) and a urine sample to look for infection. The white blood cell (WBC) count and the WBC differential can be somewhat helpful in predicting bacterial infection, though an elevated WBC count is not specific to infection. Hemoglobin concentration dictates oxygen-carrying capacity in blood, which is crucial in shock to maintain adequate tissue perfusion. Platelets, as acute-phase reactants, usually increase at the onset of any serious stress and are typically elevated in the setting of inflammation. At regular intervals, metabolic assessment should be carried out by measuring serum levels of electrolytes, including magnesium, calcium, phosphate, and glucose. Urinary tract infection (UTI) is a common source for sepsis, especially in elderly individuals. The Gram stain is the only immediately available test that can document the presence of bacterial infection and guide the choice of initial antibiotic therapy. Because most patients who present with sepsis have pneumonia, a chest radiograph is warranted. Chest radiography detects infiltrates in about 5% of febrile adults without localizing signs of infection; accordingly, it should be routine in adults who are febrile without localizing symptoms or signs and in patients who are febrile with neutropenia and without pulmonary symptoms.
Treatment
Patients with sepsis, severe sepsis, and septic shock require hospital admission. Patients with sepsis who respond to early goal-directed resuscitation therapy in the emergency department and show no evidence of end-organ hypoperfusion may be admitted to a general hospital unit, optimally one that has close nursing observation and monitoring. Such patients do not require invasive hemodynamic monitoring and usually do not require admission to an intensive care unit (ICU). Patients who do not respond to initial treatment and those who are in septic shock require admission to an ICU for continuous monitoring and continued goal-directed therapy. If an appropriate ICU bed or physician is not available, the patient should be transferred with advanced life support monitoring to another hospital with the available resources. The treatment of patients with septic shock have the following major goals start adequate antibiotic therapy as early as possible, resuscitate the patient, using supportive measures to correct hypoxia, hypotension, and impaired tissue oxygenation (hypoperfusion), identify the source of infection, and treat with antimicrobial therapy, surgery, or both, and maintain adequate organ system function, guided by cardiovascular monitoring, and interrupt the progression to multiple organ dysfunction syndrome (MODS).
Current Trends
Study suggests lower hemoglobin transfusion threshold yields similar outcomes in septic shock. In a randomized clinical trial, adults with septic shock in 32 intensive care units were randomized to a transfusion hemoglobin threshold of 7 g/dL or 9 g/dL. Outcomes among patients receiving blood transfusion at the higher hemoglobin threshold were similar to those among patients receiving blood transfusion at the lower threshold but with fewer transfusions. At 90 days after randomization, 216 of 502 patients (43.0%) assigned to the lower-threshold group, as compared with 223 of 496 (45.0%) assigned to the higher-threshold group, had died (relative risk, 0.94; 95% confidence interval, 0.78 to 1.09; P =0.44). The numbers of patients who had ischemic events, patients who had severe adverse reactions, and patients who required life support were similar in the two intervention groups (Andre Kalil, 2014).
Cultural Sensitive Care When treating patients in septic shock a lot of things must be taken into consideration. Elderly and infants are at greatest risk for complications of sepsis due to their immune systems. Therefore it is very important to catch the signs and symptoms early on in these patients to avoid further considerations.
Nursing Implications
All invasive procedures must be carried out in an aseptic technique. After care, be sure to perform proper hand hygiene. Also be sure to monitor all lines (IV, central lines, and puncture site) for signs of infection. Hyperthermia is common in these patients due to the metabolic rate and oxygen consumption. Therefore, it may not be necessary to reduce the fever as this may help to fight off the infection. It is important to promote comfort for patients with septic shock.
Conclusion
Septic shock occurs most often in the very old and the very young. It also occurs in people who have other illnesses, especially if they have a weakened immune system. Any type of bacteria can cause septic shock. Fungi and (rarely) viruses may also cause the condition. Toxins released by the bacteria or fungi may cause tissue damage, and may lead to low blood pressure and poor organ function. References
Hinkle, J., & Cheever, K. (2014). Brunner; Suddarth's textbook of medical-surgical nursing (Edition 13. ed.). Philadelphia: Lippincott Williams & Wilkins.
Kalil, MD, MPH, A. (2014, October 20). Septic Shock. Retrieved November 18, 2014, from http://emedicine.medscape.com/article/168402-overview
Sepsis. (2014, July 23). Retrieved November 18, 2014, from http://www.mayoclinic.org/diseases-conditions/sepsis/basics/symptoms/con-20031900
Septic shock: MedlinePlus Medical Encyclopedia. (2014, February 8). Retrieved November 18, 2014, from http://www.nlm.nih.gov/medlineplus/ency/article/000668.htm
Vallerand, A., & Sanoski, C. (2014). Davis's drug guide for nurses (Fourteenth ed.). Philadelphia: F.A. Davis Company.