This third-spacing of fluids contributes to a decrease in circulating blood volume and decreased preload. To maintain blood pressure, the heart will beat harder and faster, leading to a hyperdynamic state in which cardiac output is maintained early in the progression of sepsis. As sepsis continues, cardiac function can become depressed and systemic vascular resistance can decrease, leading to hypotension. Early in sepsis, derangements in the normal distribution of blood volume contribute to the development of tissue and organ hypoxia. When tissues and organs lack access to adequate oxygen, they will convert to anaerobic metabolism that will result in a metabolic acidosis from elevated lactate and other acids. To compensate, respiratory alkalosis develops as the patient increases their respiratory rate in an effort to blow off the accumulating acids in the blood in the form of carbon dioxide. Despite the increase in respiratory rate, hypoxia can develop secondary to a ventilation-perfusion mismatch that occurs as a result of the derangements in blood distribution.
As early sepsis progresses to moderate and later severe sepsis, a coagulation imbalance occurs, leading to the clinical condition of disseminated intravascular coagulation (DIC). DIC leads to clot formation in the microvasculature, and the result is thrombosis of these vessels, with impaired tissue perfusion. As the body attempts to control these multiple small clots, it overproduces and disperses anticoagulants. The downward spiral of DIC can progress rapidly as more clots form in response and then are also dissolved. Ultimately, platelets and clotting factors are consumed, and diffuse bleeding leading to petechiae and purpura will develop. End-organ failure to the heart, lungs, kidneys and liver will ensue if the situation is not corrected.
Patient History and Clinical Exam Findings
The patient with sepsis is not always easy to identify. Early signs and symptoms can be subtle, often mimicking non-life-threatening illnesses such as the common cold or flu. Familiarity with risk factors can help identify patients who are at high risk, such as the elderly and very young. Other risk factors include recent trauma or surgeries and indwelling devices such as central venous catheters, arterial catheters, urinary catheters, feeding tubes and endotracheal tubes. The immunosuppressed patient is at significant risk, as are those taking medications such as steroids, antibiotics or immunosuppressants.
All cases of severe sepsis and septic shock began as local infection. EMS providers can play a crucial role in sepsis prevention by helping identify infection sources. Identification of an infection site significantly increases your suspicion for sepsis; look during the clinical exam. Inspect bedridden patients for pressure ulcers or other open wounds, and diabetics for wounds on their legs and feet. Assess any indwelling devices for indications of infection such as redness and irritation around the insertion site. Assess for the presence of pulmonary, genitourinary, gastrointestinal or musculoskeletal infections.
The respiratory system is the most common location of infection in the septic patient.7 Question the patient or caregiver about any history of upper respiratory infection or symptoms, throat or ear pain, fever, chills or productive cough. Look for signs of infection during the clinical exam. Rales (crackles) or rhonchi on auscultation, obviously infected tonsils, and sinus or lymph node tenderness may be indicators of an infection source.
Signs and symptoms characteristic of genitourinary infection include issues with urination such as dysuria, polyuria or passing small, frequent amounts of urine. Flank pain may be present, particularly over the kidneys, as may bloody or purulent discharge from the urethra. Foley catheter placement increases the risk of urinary tract infection and has a particularly high rate of infection when Foleys are maintained in the out-of-hospital setting. Inspect any Foley catheter closely for evidence of infection, such as particulate matter in the urine. If a urinary collection bag is being used, inspect the urine for amount, color and clarity. Urine that appears cloudy, has frank blood in it, is cola-colored (indicating blood in the urine) or smells foul indicates a UTI. Inspect the genitalia for penile or vulvar ulcers or lesions and discharge as well as erythema or discharge near the catheter insertion site.
The gastrointestinal system is a common source of infection leading to sepsis, and both acute and chronic disease can lead to infection. For example, a patient with a history of diverticulosis may experience an acute diverticulitis, and rupture of an infected diverticulum can lead to sepsis. A thorough history and clinical exam should be performed on the abdomen with the specific intent of identifying an infection source.
Ask the patient or caregiver about any history of abdominal pain, and be sure to determine the pain’s description, location, onset, what makes it better or worse, quality, if it radiates and the events leading up to it. Seek information regarding the time and quality of the patient’s bowel movements and any history of nausea or vomiting.