Blood poisoning, also known as septicemia or sepsis, occurs when the bloodstream becomes infected by bacteria (i.e., staphylococci, streptococci) or fungi introduced through a wound, abscess, or other injury. Septicemia may also originate from a localized infection in the body.
Over 600,000 cases of septicemia occur in the United States each year, and approximately two-thirds of these cases are diagnosed in hospitalized patients. Septicemia is an extremely dangerous disorder because it spreads rapidly throughout the body. If bacteria continue to multiply in the bloodstream and the condition progresses to septic shock, blood pressure plummets and organ systems begin to shut down. Septic shock leads to multiple-organ dysfunction syndrome (MODS), and may result in death. Although the mortality rate of patients with sepsis has dropped from 31% in 1979 to 17.4% in 1999, over 100,000 sepsis patients die in the United States each year. Men are more likely than women to develop sepsis, and the prevalence rate among African Americans is twice the rate seen in Caucasians.
Causes & symptoms
A septic infection can originate in any wound, including burns, cuts, punctures, scrapes, abscesses, or a soft tissue infection. It can also start as a specific infection such as a sinus infection or appendicitis. Invasive surgical procedures and medical devices, such as catheters, vascular access grafts, and intravenous lines, also carry a risk of introducing bacteria to the bloodstream if not properly cleaned and cared for. A large percentage of septicemia patients contract the infection in a hospital setting.
Septicemia symptoms include:
- elevated white blood cell count
- fever and chills
- rapid breathing
- sudden drop in blood pressure
- tachycardia (a rapid, pounding heartbeat)
- confusion and possible loss of consciousness
- warm, flushed skin
- skin irregularities, such as subcutaneous red lines, swelling, bleeding under the skin, or necrosis (tissue death)
Septic shock can occur when septicemia is not treated adequately or quickly enough. Symptoms of septic shock include:
- a severe drop in blood pressure (systolic pressure less than 90 mmHG and/or less than 40 mmHG of the patient's baseline blood pressure)
- organ dysfunction (such as renal, or kidney, failure) due to reduced blood flow to the organ systems
- loss of consciousness
There are some known risk factors for developing septicemia. These include:
- Having a chronic disorder or disease. The body has a difficult time fighting infection if the immune system is already weakened.
- Use of immunosuppressive drugs. These drugs also weaken the immune system.
- Taking intravenous medications or drugs. Needles can introduce infectious organisms into the bloodstream if not used in a sterile manner.
There is no specific laboratory test for early diagnosis of septicemia. Blood cultures can sometimes determine the presence of bacteria in the bloodstream once the infection has spread; however, blood cultures require 24 hours or longer to incubate. Given the rapidly progressing nature of septicemia, cultures are more effective for confirming the diagnosis and narrowing the choice of antibiotics for treatment, as treatment usually must begin before the cultures are complete. In some cases, septicemia patients may have negative blood cultures. Further analysis of blood samples by a trained hematologist may be required to make a diagnosis. If the infection is thought to have spread from a wound or injury, tissue samples from that site may also be analyzed. Such other body fluids as urine and sputum may be cultured for organisms.
Septicemia is a potentially fatal, rapidly progressing disease. Any individual who suspects they may have septicemia should seek emergency medical care immediately.
Septicemia is treated with a course of intravenous antibiotics. The type of antibiotic used depends on the infectious agent. Blood cultures, wound cultures, and other diagnostic tests will help the healthcare provider determine which medication will be most effective. Abscesses or other sites of infection are drained of pus and
A very promising new treatment for sepsis, activated human protein C, was shown to cut the mortality rate of patients with severe sepsis by 6.1% in the first 28 days after treatment. The drug, also known as drotrecogin alfa, was approved by the FDA in the fall of 2001. It is being marketed under the trade name Xigris. Xigris cannot, however, be given to patients at high risk for active bleeding, including those who have just had surgery, have been diagnosed with an aneurysm or gastrointestinal bleeding, or are being treated with warfarin or platelet inhibitors.
There is a 17–25% mortality rate for patients with septicemia. As the disease progresses to septic shock and organ systems start to be involved, the prognosis worsens. Approximately half of all patients with septic shock die. The patient's overall physical health—especially his or her heart function—has a large bearing on his or her chance for recovery. Early intervention and aggressive treatment of localized infections offer the best chance for survival.
Meticulous infection control techniques are the best defense against septicemia. For hospitalized patients who are already at a higher risk of contracting the disease, great care should be taken to treat and clean wounds, sutures, and burns using sterile techniques in an antiseptic environment. The same applies for maintaining such invasive medical devices as intravenous lines, catheters, and gastric and nasal tubes. The use of these devices should be limited whenever possible.
One recently introduced preventive is the use of antibiotic-coated catheters in hospitalized patients. This practice is, however, controversial as of 2002. While these catheters appear to be effective in lowering the sepsis mortality rate, some doctors are concerned that their use may also encourage the development of new strains of bacteria resistant to antibiotics.
Individuals can take appropriate precautions when treating cuts, scrapes, and other minor wounds at home. Using clean or gloved hands, these injuries should be thoroughly cleaned of dirt and debris with antibacterial soap and water. A sterile compress containing a preparation of a naturally antibacterial, antiseptic herbs such as tea tree (Melaleuca alternifolia) or calendula (Calendula officinalis) can also be used to treat the wound site. A medicated cream or analgesic herbal preparation (e.g., lavender, or Lavandula angustifolia) can soothe associated pain and promote healing. A waterproof bandage will protect the wound from dirt and germs. Monitor the healing progress of these wounds closely, and contact a healthcare provider immediately should any of the symptoms of septicemia occur.
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Rebecca J. Frey, PhD