|Synonyms||Septicemia, blood poisoning|
|Blood culture bottles: orange label for anaerobes, green label for aerobes, and yellow label for blood samples from children|
|Symptoms||Fever, increased heart rate, increased breathing rate, confusion|
|Causes||Immune response triggered by an infection|
|Risk factors||Young or old age, cancer, diabetes, major trauma, burns|
|Diagnostic method||Systemic inflammatory response syndrome (SIRS), qSOFA|
|Treatment||Intravenous fluids, antibiotics|
|Prognosis||30 to 80% risk of death|
|Frequency||0.2–3 per 1000 a year (developed world)|
Sepsis is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs.Common signs and symptoms include fever, increased heart rate, increased breathing rate, and confusion. There may also be symptoms related to a specific infection, such as a cough with pneumonia, or painful urination with a kidney infection. In the very young, old, and people with a weakened immune system, there may be no symptoms of a specific infection and the body temperature may be low or normal, rather than high. Severe sepsis is sepsis causing poor organ function or insufficient blood flow. Insufficient blood flow may be evident by low blood pressure, high blood lactate, or low urine output. Septic shock is low blood pressure due to sepsis that does not improve after fluid replacement.
Infection is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to the infectious agents and the toxins they produce. Infectious disease, also known as transmissible disease or communicable disease, is illness resulting from an infection.
Fever, also known as pyrexia and febrile response, is defined as having a temperature above the normal range due to an increase in the body's temperature set point. There is not a single agreed-upon upper limit for normal temperature with sources using values between 37.5 and 38.3 °C. The increase in set point triggers increased muscle contractions and causes a feeling of cold. This results in greater heat production and efforts to conserve heat. When the set point temperature returns to normal, a person feels hot, becomes flushed, and may begin to sweat. Rarely a fever may trigger a febrile seizure. This is more common in young children. Fevers do not typically go higher than 41 to 42 °C.
Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal or abnormal.
Sepsis is caused by an inflammatory immune response triggered by an infection.Most commonly, the infection is bacterial, but it may also be fungal, viral, or protozoan. Common locations for the primary infection include the lungs, brain, urinary tract, skin, and abdominal organs. Risk factors include very young age, older age, a weakened immune system from conditions such as cancer or diabetes, major trauma, or burns. An older method of diagnosis was based on meeting at least two systemic inflammatory response syndrome (SIRS) criteria due to a presumed infection. In 2016, SIRS was replaced with a shortened sequential organ failure assessment score (SOFA score) known as the quick SOFA score (qSOFA) which is two of the following three: increased breathing rate, change in level of consciousness, and low blood pressure. Blood cultures are recommended preferably before antibiotics are started, however, infection of the blood is not required for the diagnosis. Medical imaging should be used to look for the possible location of infection. Other potential causes of similar signs and symptoms include anaphylaxis, adrenal insufficiency, low blood volume, heart failure, and pulmonary embolism.
Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, acidic hot springs, radioactive waste, and the deep portions of Earth's crust. Bacteria also live in symbiotic and parasitic relationships with plants and animals. Most bacteria have not been characterised, and only about half of the bacterial phyla have species that can be grown in the laboratory. The study of bacteria is known as bacteriology, a branch of microbiology.
A fungus is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, fungi, which is separate from the other eukaryotic life kingdoms of plants and animals.
A virus is a small infectious agent that replicates only inside the living cells of an organism. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea.
Sepsis is usually treated with intravenous fluids and antibiotics.Typically, antibiotics are given as soon as possible. Often, ongoing care is performed in an intensive care unit. If fluid replacement is not enough to maintain blood pressure, medications that raise blood pressure may be used. Mechanical ventilation and dialysis may be needed to support the function of the lungs and kidneys, respectively. To guide treatment, a central venous catheter and an arterial catheter may be placed for access to the bloodstream. Other measurements such as cardiac output and superior vena cava oxygen saturation may be used. People with sepsis need preventive measures for deep vein thrombosis, stress ulcers and pressure ulcers, unless other conditions prevent such interventions. Some might benefit from tight control of blood sugar levels with insulin. The use of corticosteroids is controversial. Drotrecogin alfa, originally marketed for severe sepsis, has not been found to be helpful, and was withdrawn from sale in 2011.
An intensive care unit (ICU), also known as an intensive therapy unit or intensive treatment unit (ITU) or critical care unit (CCU), is a special department of a hospital or health care facility that provides intensive treatment medicine.
Fluid replacement or fluid resuscitation is the medical practice of replenishing bodily fluid lost through sweating, bleeding, fluid shifts or other pathologic processes. Fluids can be replaced with oral rehydration therapy (drinking), intravenous therapy, rectally such as with a Murphy drip, or by hypodermoclysis, the direct injection of fluid into the subcutaneous tissue. Fluids administered by the oral and hypodermic routes are absorbed more slowly than those given intravenously.
Mechanical ventilation or assisted ventilation is the medical term for artificial ventilation where mechanical means is used to assist or replace spontaneous breathing. This may involve a machine called a ventilator, or the breathing may be assisted manually by a suitably qualified professional compressing a breathing system, bag valve mask device or set of bellows.
Disease severity partly determines the outcome.The risk of death from sepsis is as high as 30%, from severe sepsis as high as 50%, and from septic shock as high as 80%. The number of cases worldwide is unknown as there is little data from the developing world. Estimates suggest sepsis affects millions of people a year. In the developed world approximately 0.2 to 3 people per 1000 are affected by sepsis yearly, resulting in about a million cases per year in the United States. Rates of disease have been increasing. Sepsis is more common among males than females. The medical condition has been described since the time of Hippocrates. The terms "septicemia" and "blood poisoning" have been used in various ways and are no longer recommended.
Hippocrates of Kos, also known as Hippocrates II, was a Greek physician of the Age of Pericles, who is considered one of the most outstanding figures in the history of medicine. He is often referred to as the "Father of Medicine" in recognition of his lasting contributions to the field as the founder of the Hippocratic School of Medicine. This intellectual school revolutionized medicine in ancient Greece, establishing it as a discipline distinct from other fields with which it had traditionally been associated, thus establishing medicine as a profession.
In addition to symptoms related to the actual cause, sepsis is frequently associated with the following – fever, low body temperature, rapid breathing, a fast heart rate, confusion, and edema. Early signs include a rapid heart rate, decreased urination, and high blood sugar. Signs of established sepsis include confusion, metabolic acidosis (which may be accompanied by a faster breathing rate that leads to respiratory alkalosis), low blood pressure due to decreased systemic vascular resistance, higher cardiac output, and disorders in blood-clotting that may lead to organ failure.
Hypothermia is reduced body temperature that happens when a body dissipates more heat than it absorbs. In humans, it is defined as a body core temperature below 35.0 °C (95.0 °F). Symptoms depend on the temperature. In mild hypothermia there is shivering and mental confusion. In moderate hypothermia shivering stops and confusion increases. In severe hypothermia, there may be paradoxical undressing, in which a person removes their clothing, as well as an increased risk of the heart stopping.
Tachypnea is abnormally rapid breathing.
Edema, also spelled oedema or œdema, is an abnormal accumulation of fluid in the interstitium, located beneath the skin and in the cavities of the body, which can cause severe pain. Clinically, edema manifests as swelling. The amount of interstitial fluid is determined by the balance of fluid homeostasis and the increased secretion of fluid into the interstitium. The word is from Greek οἴδημα oídēma meaning "swelling". The condition is also known as dropsy.
The drop in blood pressure seen in sepsis can cause lightheadedness and is part of the criteria for septic shock.
Hypotension is low blood pressure, especially in the arteries of the systemic circulation. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. A systolic blood pressure of less than 90 millimeters of mercury or diastolic of less than 60 mm Hg is generally considered to be hypotension. However, in practice, blood pressure is considered too low only if noticeable symptoms are present.
Lightheadedness is a common and typically unpleasant sensation of dizziness and/or a feeling that one may faint. The sensation of lightheadedness can be short-lived, prolonged, or, rarely, recurring. In addition to dizziness, the individual may feel as though his or her head is weightless. The individual may also feel as though the room is "spinning" or moving (vertigo) associated with lightheadedness. Most causes of lightheadedness are not serious and either cure themselves quickly, or are easily treated.
Septic shock is a potentially fatal medical condition that occurs when sepsis, which is organ injury or damage in response to infection, leads to dangerously low blood pressure and abnormalities in cellular metabolism.
Infections leading to sepsis are usually bacterial, but may be fungal or viral.Gram-positive bacteria was the predominant cause of sepsis before the introduction of antibiotics in the 1950s. After the introduction of antibiotics, gram-negative bacteria became the predominant cause of sepsis from the 1960s to the 1980s. After the 1980s, gram-positive bacteria, most commonly staphylococci, are thought to cause more than 50% of cases of sepsis. Other commonly implicated bacteria include Streptococcus pyogenes , Escherichia coli , Pseudomonas aeruginosa , and Klebsiella species. Fungal sepsis accounts for approximately 5% of severe sepsis and septic shock cases; the most common cause of fungal sepsis is infection by Candida species of yeast, a frequent hospital-acquired infection.
The most common sites of infection resulting in severe sepsis are the lungs, the abdomen, and the urinary tract.Typically, 50% of all sepsis cases start as an infection in the lungs. No definitive source is found in one third to one half of cases.
Early diagnosis is necessary to properly manage sepsis, as initiation of rapid therapy is key to reducing deaths from severe sepsis.Some hospitals use alerts generated from electronic health records to bring attention to potential cases as early as possible.
Within the first three hours of suspected sepsis, diagnostic studies should include white blood cell counts, measuring serum lactate, and obtaining appropriate cultures before starting antibiotics, so long as this does not delay their use by more than 45 minutes.To identify the causative organism(s), at least two sets of blood cultures using bottles with media for aerobic and anaerobic organisms should be obtained, with at least one drawn through the skin and one drawn through each vascular access device (such as an IV catheter) in place more than 48 hours. Bacteria are present in the blood in only about 30% of cases. Another possible method of detection is by polymerase chain reaction. If other sources of infection are suspected, cultures of these sources, such as urine, cerebrospinal fluid, wounds, or respiratory secretions, also should be obtained, as long as this does not delay the use of antibiotics.
Within six hours, if blood pressure remains low despite initial fluid resuscitation of 30 ml/kg, or if initial lactate is ≥ 4 mmol/l (36 mg/dl), central venous pressure and central venous oxygen saturation should be measured. Lactate should be re-measured if the initial lactate was elevated. Evidence for point of care lactate measurement over usual methods of measurement, however, is poor.
Within twelve hours, it is essential to diagnose or exclude any source of infection that would require emergent source control, such as necrotizing soft tissue infection, infection causing inflammation of the abdominal cavity lining, infection of the bile duct, or intestinal infarction.A pierced internal organ (free air on abdominal x-ray or CT scan), an abnormal chest x-ray consistent with pneumonia (with focal opacification), or petechiae, purpura, or purpura fulminans may be evident of infection.
|Temperature||<36 °C (96.8 °F) or >38 °C (100.4 °F)|
|Respiratory rate||>20/min or PaCO2<32 mmHg (4.3 kPa)|
|WBC||<4x109/L (<4000/mm³), >12x109/L (>12,000/mm³), or 10% bands|
Previously, SIRS criteria had been used to define sepsis. If the SIRS criteria are negative, it is very unlikely the person has sepsis; if it is positive, there is just a moderate probability that the person has sepsis. According to SIRS, there were different levels of sepsis: sepsis, severe sepsis, and septic shock.The definition of SIRS is shown below:
In 2016 a new consensus was reached to replace screening by systemic inflammatory response syndrome (SIRS) with qSOFA.However, the American College of Chest Physicians (CHEST) raised concerns that qSOFA and SOFA criteria may lead to delayed diagnosis of serious infection, leading to delayed treatment. Although SIRS criteria can be too sensitive and not specific enough in identifying sepsis, SOFA also has its own limitation and is not intended to replace the SIRS definition. qSOFA has also been found to be poorly sensitive though decently specific for the risk of death with SIRS possibly better for screening.
Examples of end-organ dysfunction include the following:
More specific definitions of end-organ dysfunction exist for SIRS in pediatrics.
Consensus definitions, however, continue to evolve, with the latest expanding the list of signs and symptoms of sepsis to reflect clinical bedside experience.
A 2013 review concluded moderate-quality evidence exists to support use of the procalcitonin level as a method to distinguish sepsis from non-infectious causes of SIRS.The same review found the sensitivity of the test to be 77% and the specificity to be 79%. The authors suggested that procalcitonin may serve as a helpful diagnostic marker for sepsis, but cautioned that its level alone cannot definitively make the diagnosis. A 2012 systematic review found that soluble urokinase-type plasminogen activator receptor (SuPAR) is a nonspecific marker of inflammation and does not accurately diagnose sepsis. This same review concluded, however, that SuPAR has prognostic value, as higher SuPAR levels are associated with an increased rate of death in those with sepsis.
The differential diagnosis for sepsis is broad and has to examine (in order to exclude) the non-infectious conditions that may cause the systemic signs of SIRS: alcohol withdrawal, acute pancreatitis, burns, pulmonary embolism, thyrotoxicosis, anaphylaxis, adrenal insufficiency, and neurogenic shock.Hyperinflammatory syndromes such as hemophagocytic lymphohistiocytosis (HLH) may have similar symptoms and should also be included in differential diagnosis.
In common clinical usage, neonatal sepsis refers to a bacterial blood stream infection in the first month of life, such as meningitis, pneumonia, pyelonephritis, or gastroenteritis,but neonatal sepsis also may be due to infection with fungi, viruses, or parasites. Criteria with regard to hemodynamic compromise or respiratory failure are not useful because they present too late for intervention.
Sepsis is caused by a combination of factors related to the particular invading pathogen(s) and to the status of the immune system of the host.The early phase of sepsis characterized by excessive inflammation (sometimes resulting in a cytokine storm) may be followed by a prolonged period of decreased functioning of the immune system. Either of these phases may prove fatal. On the other hand, systemic inflammatory response syndrome (SIRS) occurs in people without the presence of infection, for example, in those with burns, polytrauma, or the initial state in pancreatitis and chemical pneumonitis. However, sepsis also causes similar response to SIRS.
Bacterial virulence factors, such as glycocalyx and various adhesins, allow colonization, immune evasion, and establishment of disease in the host.Sepsis caused by gram-negative bacteria is thought to be largely due to a response by the host to the lipid A component of lipopolysaccharide, also called endotoxin. Sepsis caused by gram-positive bacteria may result from an immunological response to cell wall lipoteichoic acid. Bacterial exotoxins that act as superantigens also may cause sepsis. Superantigens simultaneously bind major histocompatibility complex and T-cell receptors in the absence of antigen presentation. This forced receptor interaction induces the production of pro-inflammatory chemical signals (cytokines) by T-cells.
There are a number of microbial factors that may cause the typical septic inflammatory cascade. An invading pathogen is recognized by its pathogen-associated molecular patterns (PAMPs). Examples of PAMPs include lipopolysaccharides and flagellin in gram-negative bacteria, muramyl dipeptide in the peptidoglycan of the gram-positive bacterial cell wall, and CpG bacterial DNA. These PAMPs are recognized by the pattern recognition receptors (PRRs) of the innate immune system, which may be membrane-bound or cytosolic.There are four families of PRRs: the toll-like receptors, the C-type lectin receptors, the NOD-like receptors, and the RIG-I-like receptors. Invariably, the association of a PAMP and a PRR will cause a series of intracellular signalling cascades. Consequentially, transcription factors such as nuclear factor-kappa B and activator protein-1, will up-regulate the expression of pro-inflammatory and anti-inflammatory cytokines.
Upon detection of microbial antigens, the host systemic immune system is activated. Immune cells not only recognise pathogen-associated molecular patterns, but also damage-associated molecular patterns from damaged tissues. An uncontrolled immune response is then activated because leukocytes are not recruited to the specific site of infection, but instead they are recruited all over the body. Then, an immunosuppression state ensues when the proinflammatory T helper cell 1 (TH1) is shifted to TH2,mediated by interleukin 10, which is known as "compensatory anti-inflammatory response syndrome". The apoptosis (cell death) of lymphocytes further worsens the immunosuppression. Subsequently, multiple organ failure ensues because tissues are unable to use oxygen efficiently due to inhibition of cytochrome c oxidase.
Inflammatory responses cause multiple organ dysfunction syndrome through various mechanisms as described below. Increased permeability of the lung vessels causes leaking of fluids into alveoli, which results in pulmonary edema and acute respiratory distress syndrome (ARDS). Impaired utilization of oxygen in the liver impairs bile salt transport, causing jaundice (yellowish discoloration of skin). In kidneys, inadequate oxygenation results in tubular epithelial cell injury (of the cells lining the kidney tubules), and thus causes acute kidney injury (AKI). Meanwhile, in a human heart, impaired calcium transport, and low production of adenosine triphosphate (ATP), can cause myocardial depression, reducing cardiac contractility and causing heart failure. In the gastrointestinal tract, increased permeability of the mucosa alters the microflora, causing mucosal bleeding and paralytic ileus. In the central nervous system, direct damage of the brain cells and disturbances of neurotransmissions causes altered mental status.Cytokines such as tumor necrosis factor, interleukin 1, and interleukin 6 may activate procoagulation factors in the cells lining blood vessels, leading to endothelial damage. The damaged endothelial surface inhibits anticoagulant properties as well as increases antifibrinolysis, which may lead to intravascular clotting, the formation of blood clots in small blood vessels, and multiple organ failure.
The low blood pressure seen in those with sepsis is the result of various processes, including excessive production of chemicals that dilate blood vessels such as nitric oxide, a deficiency of chemicals that constrict blood vessels such as vasopressin, and activation of ATP-sensitive potassium channels.In those with severe sepsis and septic shock, this sequence of events leads to a type of circulatory shock known as distributive shock.
Early recognition and focused management may improve the outcomes in sepsis. Current professional recommendations include a number of actions ("bundles") to be followed as soon as possible after diagnosis. Within the first three hours someone with sepsis should have received antibiotics and, intravenous fluids if there is evidence of either low blood pressure or other evidence for inadequate blood supply to organs (as evidenced by a raised level of lactate); blood cultures also should be obtained within this time period. After six hours the blood pressure should be adequate, close monitoring of blood pressure and blood supply to organs should be in place, and the lactate should be measured again if initially, it was raised.A related bundle, the "Sepsis Six", is in widespread use in the United Kingdom; this requires the administration of antibiotics within an hour of recognition, blood cultures, lactate and hemoglobin determination, urine output monitoring, high-flow oxygen, and intravenous fluids.
Apart from the timely administration of fluids and antibiotics, the management of sepsis also involves surgical drainage of infected fluid collections and appropriate support for organ dysfunction. This may include hemodialysis in kidney failure, mechanical ventilation in lung dysfunction, transfusion of blood products, and drug and fluid therapy for circulatory failure. Ensuring adequate nutrition—preferably by enteral feeding, but if necessary, by parenteral nutrition—is important during prolonged illness.Medication to prevent deep vein thrombosis and gastric ulcers also may be used.
Two sets of blood cultures (aerobic and anaerobic) should be taken without delaying the initiation of antibiotics. Cultures from other sites such as respiratory secretions, urine, wounds, cerebrospinal fluid, and catheter insertion sites (in-situ more than 48 hours) can be taken if infections from these sites are suspected.In severe sepsis and septic shock, broad-spectrum antibiotics (usually two, a β-lactam antibiotic with broad coverage, or broad-spectrum carbapenem combined with fluoroquinolones, macrolides, or aminoglycosides) are recommended. However, combination of antibiotics is not recommended for the treatment of sepsis but without shock and immunocompromised persons unless the combination is used to broaden the anti-bacterial activity. The choice of antibiotics is important in determining the survival of the person. Some recommend they be given within one hour of making the diagnosis, stating that for every hour of delay in the administration of antibiotics, there is an associated 6% rise in mortality. Others did not find a benefit with early administration.
Several factors determine the most appropriate choice for the initial antibiotic regimen. These factors include local patterns of bacterial sensitivity to antibiotics, whether the infection is thought to be a hospital or community-acquired infection, and which organ systems are thought to be infected. days with the type of antibiotic used directed by the results of cultures. If the culture result is negative, antibiotics should be de-escalated according to person's clinical response or stopped altogether if infection is not present to decrease the chances that the person is infected with multiple drug resistance organisms. In case of people having high risk of being infected with multiple drug resistance organisms such as Pseudomonas aeruginosa , Acinetobacter baumannii , addition of antibiotic specific to gram-negative organism is recommended. For Methicillin-resistant Staphylococcus aureus (MRSA), vancomycin or teicoplanin is recommended. For Legionella infection, addition of macrolide or fluoroquinolone is chosen. If fungal infection is suspected, an echinocandin, such as caspofungin or micafungin, is chosen for people with severe sepsis, followed by triazole (fluconazole and itraconazole) for less ill people. Prolonged antibiotic prophylaxis is not recommended in people who has SIRS without any infectious origin such as acute pancreatitis and burns unless sepsis is suspected.Antibiotic regimens should be reassessed daily and narrowed if appropriate. Treatment duration is typically 7–10
Once daily dosing of aminoglycoside is sufficient to achieve peak plasma concentration for clinical response without kidney toxicity. Meanwhile, for antibiotics with low volume distribution (vancomycin, teicoplanin, colistin), loading dose is required to achieve adequate therapeutic level to fight infections. Frequent infusions of beta-lactam antibiotics without exceeding total daily dose would help to keep the antibiotics level above minimum inhibitory concentration (MIC), thus providing better clinical response.Giving beta-lactam antibiotics continuously may be better than giving them intermittently. Access to therapeutic drug monitoring is important to ensure adequate drug therapeutic level while at the same time preventing the drug from reaching toxic level.
The Surviving Sepsis Campaign has recommended 30 ml/kg of fluid to be given in adults in the first 3 hours followed by fluid titration according to blood pressure, urine output, respiratory rate, and oxygen saturation with a target mean arterial pressure (MAP) of 65 mmHg. g/dL and then inotropes are added until the ScvO2 is optimized. In those with acute respiratory distress syndrome (ARDS) and sufficient tissue blood fluid, more fluids should be given carefully.In children an initial amount of 20ml/kg is reasonable in shock. In cases of severe sepsis and septic shock where a central venous catheter is used to measure blood pressures dynamically, fluids should be administered until the central venous pressure (CVP) reaches 8–12mmHg. Once these goals are met, the central venous oxygen saturation (ScvO2), i.e., the oxygen saturation of venous blood as it returns to the heart as measured at the vena cava, is optimized. If the ScvO2 is less than 70%, blood may be given to reach a hemoglobin of 10
Crystalloid is recommended as the fluid of choice for resuscitation.Albumin can be used if large amount of crystalloid is required for resuscitaition. Crystalloid solutions shows little difference with hydroxyethyl starch in terms of risk of death. Starches also carry an increased risk of acute kidney injury, and need for blood transfusion. Various colloid solutions (such as modified gelatin) carry no advantage over crystalloid. Albumin also appears to be of no benefit over crystalloids.
The Surviving Sepsis Campaign recommended packed red blood cells transfusion for hemoglobin levels below 70 g/L if there is no myocardial ischemia, hypoxemia, or acute bleeding.In a 2014 trial, blood transfusions to keep target hemoglobin above 70 or 90 g/L did not make any difference to survival rates; meanwhile, those with a lower threshold of transfusion received fewer transfusions in total. Erythropoietin is not recommended in the treatment of anemia with septic shock because it may precipitate blood clotting events. Fresh frozen plasma transfusion usually does not correct the underlying clotting abnormalities before a planned surgical procedure. However, platelet transfusion is suggested for platelet counts below (10 × 109/L) without any risk of bleeding, or (20 × 109/L) with high risk of bleeding, or (50 × 109/L) with active bleeding, before a planned surgery or an invasive procedure. IV immunoglobulin is not recommended because its beneficial effects are uncertain. Monoclonal and polyclonal preparations of intravenous immunoglobulin (IVIG) do not lower the rate of death in newborns and adults with sepsis. Evidence for the use of IgM-enriched polyclonal preparations of IVIG is inconsistent. On the other hand, the use of antithrombin to treat disseminated intravascular coagulation is also not useful. Meanwhile, the blood purification technique (such as hemoperfusion, plasma filtration, and coupled plasma filtration adsorption) to remove inflammatory mediators and bacterial toxins from the blood also does not demonstrate any survival benefit for septic shock.
If the person has been sufficiently fluid resuscitated but the mean arterial pressure is not greater than 65 mmHg, vasopressors are recommended. Norepinephrine (noradrenaline) is recommended as the initial choice.
Norepinephrine is often used as a first-line treatment for hypotensive septic shock because evidence shows that there is a relative deficiency of vasopressin, when shock continues for 24 to 48 hours.Norepinephrine raises blood pressure through a vasoconstriction effect, with little effect on stroke volume and heart rate. In some people, the required dose of vasopressor needed to increase the mean arterial pressure can become exceedingly high that it becomes toxic. In order to reduce the required dose of vasopressor, epinephrine may be added. Epinephrine is not often used as a first-line treatment for hypotensive shock because it reduces blood flow to the abdominal organs and increases lactate levels. However, one of the adrenaline side effects is that it reduces blood flow to abdominal organs and may cause increased lactate levels. Vasopressin can be used in septic shock because studies have shown that there is a relative deficiency of vasopressin when shock continues for 24 to 48 hours. However, vasopressin reduces blood flow to the heart, finger/toes, and abdominal organs, resulting in a lack of oxygen supply to these tissues. Dopamine is typically not recommended. Although dopamine is useful to increase the stroke volume of the heart, it causes more abnormal heart rhythms than norepinephrine and also has an immunosuppressive effect. Dopamine is not proven to have protective properties on the kidneys. Dobutamine can also be used in hypotensive septic shock to increase cardiac output and correct blood flow to the tissues. Dobutamine is not used as often as epinephrine due to its associate side effects, which include reducing blood flow to the gut. Additionally, dobutamine increases the cardiac output by abnormally increasing the heart rate.
The use of steroids in sepsis is controversial.Studies do not give a clear picture as to whether and when glucocorticoids should be used. The 2016 Surviving Sepsis Campaign recommends against their use in those with septic shock if intravenous fluids and vasopressors are able to stabilize the person's cardiovascular function. Low dose hydrocortisone is only used if both intravenous fluids and vasopressors are not able to adequately treat septic shock. A 2015 Cochrane review found low-quality evidence of benefit.
During critical illness, a state of adrenal insufficiency and tissue resistance to corticosteroids may occur. This has been termed critical illness–related corticosteroid insufficiency.Treatment with corticosteroids might be most beneficial in those with septic shock and early severe ARDS, whereas its role in others such as those with pancreatitis or severe pneumonia is unclear. However, the exact way of determining corticosteroid insufficiency remains problematic. It should be suspected in those poorly responding to resuscitation with fluids and vasopressors. Neither ACTH stimulation testing nor random cortisol levels are recommended to confirm the diagnosis. The method of stopping glucocorticoid drugs is variable, and it is unclear whether they should be slowly decreased or simply abruptly stopped. However, the 2016 Surviving Sepsis Campaign recommended to taper steroids when vasopressors are no longer needed.
A target tidal volume of 6 mL/kg of predicted body weight (PBW) and a plateau pressure less than 30 cm H2O is recommended for those who require ventilation due to sepsis-induced severe ARDS. High positive end expiratory pressure (PEEP) is recommended for moderate to severe ARDS in sepsis as it opens more lung units for oxygen exchange. Predicted body weight is calculated based on sex and height, and tools for this are available. Recruitment maneuvers may be necessary for severe ARDS by briefly raising the transpulmonary pressure. It is recommended that the head of the bed be raised if possible to improve ventilation. However, β2 adrenergic receptor agonists are not recommended to treat ARDS because it may reduce survival rates and precipitate abnormal heart rhythms. A spontaneous breathing trial using continuous positive airway pressure (CPAP), T piece, or inspiratory pressure augmentation can be helpful in reducing the duration of ventilation. Minimizing intermittent or continuous sedation is helpful in reducing the duration of mechanical ventilation.
General anesthesia is recommended for people with sepsis who require surgical procedures to remove the infective source. Usually inhalational and intravenous anesthetics are used. Requirements for anesthetics may be reduced in sepsis. Inhalational anesthetics can reduce the level of proinflammatory cytokines, altering leukocyte adhesion and proliferation, inducing apoptosis (cell death) of the lymphocytes, possibly with a toxic effect on mitochondrial function.Although etomidate has a minimal effect on the cardiovascular system, it is often not recommended as a medication to help with intubation in this situation due to concerns it may lead to poor adrenal function and an increased risk of death. The small amount of evidence there is, however, has not found a change in the risk of death with etomidate.
Paralytic agents are not suggested for use in sepsis cases in the absence of ARDS, as a growing body of evidence points to reduced durations of mechanical ventilation, ICU and hospital stays.However, paralytic use in ARDS cases remains controversial. When appropriately used, paralytics may aid successful mechanical ventilation, however evidence has also suggested that mechanical ventilation in severe sepsis does not improve oxygen consumption and delivery.
Early goal directed therapy (EGDT) is an approach to the management of severe sepsis during the initial 6 hours after diagnosis. It is a step-wise approach, with the physiologic goal of optimizing cardiac preload, afterload, and contractility. It includes giving early antibiotics. EGDT also involves monitoring of hemodynamic parameters and specific interventions to achieve key resuscitation targets which include maintaining a central venous pressure between 8–12 mmHg, a mean arterial pressure of between 65–90 mmHg, a central venous oxygen saturation (ScvO2) greater than 70% and a urine output of greater than 0.5 ml/kg/hour. The goal is to optimize oxygen delivery to tissues and achieve a balance between systemic oxygen delivery and demand. An appropriate decrease in serum lactate may be equivalent to ScvO2 and easier to obtain.
In the original trial, early goal directed therapy was found to reduce mortality from 46.5% to 30.5% in those with sepsis,and the Surviving Sepsis Campaign has been recommending its use. However, three more recent large randomized control trials (ProCESS, ARISE, and ProMISe), did not demonstrate a 90-day mortality benefit of early goal directed therapy when compared to standard therapy in severe sepsis. It is likely that some parts of EGDT are more important than others. Following these trials the use of EGDT is still considered reasonable.
Neonatal sepsis can be difficult to diagnose as newborns may be asymptomatic.If a newborn shows signs and symptoms suggestive of sepsis, antibiotics are immediately started and are either changed to target a specific organism identified by diagnostic testing or discontinued after an infectious cause for the symptoms has been ruled out. Despite early intervention, death occurs in 13% of children who develop septic shock, with the risk partly based on other health problems. Those without multiple organ system failure or who require only one inotropic agent mortality is low.
Treating fever in sepsis, including people in septic shock, has not been associated with any improvement in mortality over a period of 28 days.Treatment of fever still occurs for other reasons.
A 2012 Cochrane review concluded that N-acetylcysteine does not reduce mortality in those with SIRS or sepsis and may even be harmful.
Recombinant activated protein C (drotrecogin alpha) was originally introduced for severe sepsis (as identified by a high APACHE II score), where it was thought to confer a survival benefit.However, subsequent studies showed that it increased adverse events—bleeding risk in particular—and did not decrease mortality. It was removed from sale in 2011. Another medication known as eritoran also has not shown benefit.
In those with high blood sugar levels, insulin to bring it down to 7.8–10 mmol/L (140–180 mg/dL) is recommended with lower levels potentially worsening outcomes. Glucose levels taken from capillary blood should be interpreted with care because such measurements may not be accurate. If a person has an arterial catheter, arterial blood is recommended for blood glucose testing.
Intermittent or continuous renal replacement therapy may be used if indicated. However, sodium bicarbonate is not recommended for a person with lactic acidosis secondary to hypoperfusion. Low molecular weight heparin (LMWH), unfractionated heparin (UFH), and mechanical prophylaxis with intermittent pneumatic compression devices are recommended for any person with sepsis at moderate to high risk of venous thromboembolism.Stress ulcer prevention with proton-pump inhibitor (PPI) and H2 antagonist are useful in a person with risk factors of developing upper gastrointestinal bleeding (UGIB) such as on mechanical ventilation for more than 48 hours, coagulation disorders, liver disease, and renal replacement therapy. Achieving partial or full enteral feeding (delivery of nutrients through a feeding tube) is chosen as the best approach to provide nutrition for a person who is contraindicated for oral intake or unable to tolerate orally in the first seven days of sepsis when compared to intravenous nutrition. However, omega-3 fatty acids are not recommended as immune supplements for a person with sepsis or septic shock. The usage of prokinetic agents such as metoclopramide, domperidone, and erythromycin are recommended for those who are septic and unable to tolerate enteral feeding. However, these agents may precipitate prolongation of the QT interval and consequently provoke a ventricular arrhythmia such as torsades de pointes. The usage of prokinetic agents should be reassessed daily and stopped if no longer indicated.
Severe sepsis will prove fatal in approximately 20–35% of people, and septic shock will prove fatal in 30–70% of people. mmol/L having a mortality of 40% and those with a level of less than 2 mmol/L having a mortality of less than 15%.Lactate is a useful method of determining prognosis, with those who have a level greater than 4
There are a number of prognostic stratification systems, such as APACHE II and Mortality in Emergency Department Sepsis. APACHE II factors in the person's age, underlying condition, and various physiologic variables to yield estimates of the risk of dying of severe sepsis. Of the individual covariates, the severity of underlying disease most strongly influences the risk of death. Septic shock is also a strong predictor of short- and long-term mortality. Case-fatality rates are similar for culture-positive and culture-negative severe sepsis. The Mortality in Emergency Department Sepsis (MEDS) score is simpler, and useful in the emergency department environment.
Some people may experience severe long-term cognitive decline following an episode of severe sepsis, but the absence of baseline neuropsychological data in most people with sepsis makes the incidence of this difficult to quantify or to study.
Sepsis causes millions of deaths globally each year and is the most common cause of death in people who have been hospitalized.The worldwide incidence of sepsis is estimated to be 18 million cases per year. In the United States sepsis affects approximately 3 in 1,000 people, and severe sepsis contributes to more than 200,000 deaths per year.
Sepsis occurs in 1–2% of all hospitalizations and accounts for as much as 25% of ICU bed utilization. Due to it rarely being reported as a primary diagnosis (often being a complication of cancer or other illness), the incidence, mortality, and morbidity rates of sepsis are likely underestimated.A study of U.S. states found approximately 651 hospital stays per 100,000 population with a sepsis diagnosis in 2010. It is the second-leading cause of death in non-coronary intensive care unit (ICU) and the tenth-most-common cause of death overall (the first being heart disease). Children under 12 months of age and elderly people have the highest incidence of severe sepsis. Among U.S. patients who had multiple sepsis hospital admissions in 2010, those who were discharged to a skilled nursing facility or long term care following the initial hospitalization were more likely to be readmitted than those discharged to another form of care. A study of 18 U.S. states found that, amongst Medicare patients in 2011, sepsis was the second most common principal reason for readmission within 30 days.
Several medical conditions increase a person's susceptibility to infection and developing sepsis. Common sepsis risk factors include age (especially the very young and old); conditions that weaken the immune system such as cancer, diabetes, or the absence of a spleen; and major trauma and burns.
From 1979 to 2000, data from the United States National Hospital Discharge Survey showed that the incidence of sepsis increased fourfold, to 240 cases per 100,000 population, with higher incidence in men when compared to women. During the same time frame, the in-hospital case fatality rate was reduced from 28% to 18%. However, according to the nationwide inpatient sample from the United States, the incidence of severe sepsis increased from 200 per 10,000 population in 2003 to 300 cases in 2007 for population aged more than 18 years. The incidence rate is particularly high among infants, with the incidence of 500 cases per 100,000 population. Mortality related to sepsis increases with age, from less than 10% in the age group of 3 to 5 years to 60% by sixth decade of life.The increase in average age of the population, alongside the presence of more people with chronic diseases or on immunosuppressive medications, and also the increase in the number of invasive procedures being performed, has led to an increased rate of sepsis.
The term "σήψις" (sepsis) was introduced by Hippocrates in the fourth century BC, and it meant the process of decay or decomposition of organic matter. – sepsis – was used for this condition.In the eleventh century, Avicenna used the term "blood rot" for diseases linked to severe purulent process. Though severe systemic toxicity had already been observed, it was only in the 19th century that the specific term
The terms "septicemia", also spelled "septicaemia", and "blood poisoning" referred to the microorganisms or their toxins in the blood and are no longer commonly used.The modern term for this is bacteremia.
By the end of the 19th century, it was widely believed that microbes produced substances that could injure the mammalian host and that soluble toxins released during infection caused the fever and shock that were commonplace during severe infections. Pfeiffer coined the term endotoxin at the beginning of the 20th century to denote the pyrogenic principle associated with Vibrio cholerae . It was soon realised that endotoxins were expressed by most and perhaps all gram-negative bacteria. The lipopolysaccharide character of enteric endotoxins was elucidated in 1944 by Shear.The molecular character of this material was determined by Luderitz et al. in 1973.
It was discovered in 1965 that a strain of C3H/HeJ mice were immune to the endotoxin-induced shock.The genetic locus for this effect was dubbed Lps. These mice were also found to be hypersusceptible to infection by gram-negative bacteria. These observations were finally linked in 1998 by the discovery of the toll-like receptor gene 4 (TLR 4). Genetic mapping work, performed over a period of five years, showed that TLR4 was the sole candidate locus within the Lps critical region; this strongly implied that a mutation within TLR4 must account for the lipopolysaccharide resistance phenotype. The defect in the TLR4 gene that led to the endotoxin resistant phenotype was discovered to be due to a mutation in the cytoplasm.
Controversy occurred in the scientific community over the use of mouse models in research into sepsis in 2013, when scientists published a review of the mouse immune system compared to the human immune system, and showed that on a systems level, the two worked very differently; the authors noted that as of the date of their article over 150 clinical trials of sepsis had been conducted in humans, almost all of them supported by promising data in mice, and that all of them had failed. The authors called for abandoning the use of mouse models in sepsis research; others rejected that but called for more caution in interpreting the results of mouse studies, and more careful design of preclinical studies.One approach is to rely more on studying biopsies and clinical data from people who have had sepsis, to try to identify biomarkers and drug targets for intervention.
Sepsis was the most expensive condition treated in United States' hospital stays in 2013, at an aggregate cost of $23.6 billion for nearly 1.3 million hospitalizations.Costs for sepsis hospital stays more than quadrupled since 1997 with an 11.5 percent annual increase. By payer, it was the most costly condition billed to Medicare and the uninsured, the second-most costly billed to Medicaid, and the fourth-most costly billed to private insurance.
A large international collaboration entitled the "Surviving Sepsis Campaign" was established in 2002to educate people about sepsis and to improve patient outcomes with sepsis. The Campaign has published an evidence-based review of management strategies for severe sepsis, with the aim to publish a complete set of guidelines in subsequent years.
Sepsis Alliance is a charitable organization that was created to raise sepsis awareness among both the general public and healthcare professionals.
Shock is the state of not enough blood flow to the tissues of the body as a result of problems with the circulatory system. Initial symptoms may include weakness, fast heart rate, fast breathing, sweating, anxiety, and increased thirst. This may be followed by confusion, unconsciousness, or cardiac arrest as complications worsen.
Disseminated intravascular coagulation (DIC) is a condition in which blood clots form throughout the body, blocking small blood vessels. Symptoms may include chest pain, shortness of breath, leg pain, problems speaking, or problems moving parts of the body. As clotting factors and platelets are used up, bleeding may occur. This may include blood in the urine, blood in the stool, or bleeding into the skin. Complications may include organ failure.
Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath, rapid breathing, and bluish skin coloration. Among those who survive, a decreased quality of life is relatively common.
Septic arthritis, also known as joint infection or infectious arthritis, is the invasion of a joint by an infectious agent resulting in joint inflammation. Symptoms typically include redness, heat, and pain in a single joint associated with a decreased ability to move the joint. Onset is usually rapid. Other symptoms may include fever, weakness, and headache. Occasionally, more than one joint may be involved.
Procalcitonin (PCT) is a peptide precursor of the hormone calcitonin, the latter being involved with calcium homeostasis. It arises once preprocalcitonin is cleaved by endopeptidase. It was first identified by Leonard J. Deftos and Bernard A. Roos in the 1970s. It is composed of 116 amino acids and is produced by parafollicular cells of the thyroid and by the neuroendocrine cells of the lung and the intestine.
Systemic inflammatory response syndrome (SIRS) is an inflammatory state affecting the whole body. It is the body's response to an infectious or noninfectious insult. Although the definition of SIRS refers to it as an "inflammatory" response, it actually has pro- and anti-inflammatory components.
Multiple organ dysfunction syndrome (MODS), also known as multiple organ failure (MOF), total organ failure (TOF) or multisystem organ failure (MSOF), is altered organ function in an acutely ill patient requiring medical intervention to achieve homeostasis.
Hyperchloremia is an electrolyte disturbance in which there is an elevated level of the chloride ions in the blood. The normal serum range for chloride is 96 to 106 mEq/L, therefore chloride levels at or above 110 mEq/L usually indicate kidney dysfunction as it is a regulator of chloride concentration. As of now there are no specific symptoms of hyperchloremia, however, it can be the influenced by multiple abnormalities that cause a loss of electrolyte-free fluid, loss of hypotonic fluid, or increased administration of sodium chloride. These abnormalities are caused by diarrhea, vomiting, increased sodium chloride intake, renal dysfunction, diuretic use, and diabetes. Hyperchloremia should not be mistaken for hyperchloremic metabolic acidosis as hyperchloremic metabolic acidosis is characterized by two major changes: a decrease in blood pH and bicarbonate levels, as well as an increase in blood chloride levels. Instead those with hyperchloremic metabolic acidosis are usually predisposed to hyperchloremia.
Distributive shock is a medical condition in which abnormal distribution of blood flow in the smallest blood vessels results in inadequate supply of blood to the body's tissues and organs. It is one of four categories of shock, a condition where there is not enough oxygen-carrying blood to meet the metabolic needs of the cells which make up the body's tissues and organs. Distributive shock is different from the other three categories of shock in that it occurs even though the output of the heart is at or above a normal level. The most common cause is sepsis leading to type of distributive shock called septic shock, a condition that can be fatal.
Thyroid storm or thyrotoxic crisis is a rare but severe and potentially life-threatening complication of hyperthyroidism. It is characterized by a high fever, fast and often irregular heart beat, elevated blood pressure, vomiting, diarrhea, and agitation. Hypertension with a wide pulse pressure occurs in early to mid crisis, with hypotension accompanying shock occurring in the late stage. Heart failure and heart attack may occur. Death may occur despite treatment. Most episodes occur either in those with known hyperthyroidism whose treatment has been stopped or become ineffective, or in those with untreated mild hyperthyroidism who have developed an intercurrent illness.
The sequential organ failure assessment score, previously known as the sepsis-related organ failure assessment score, is used to track a person's status during the stay in an intensive care unit (ICU) to determine the extent of a person's organ function or rate of failure. The score is based on six different scores, one each for the respiratory, cardiovascular, hepatic, coagulation, renal and neurological systems.
Capillary leak syndrome is characterized by the escape of blood plasma through capillary walls, from the blood circulatory system to surrounding tissues, muscle compartments, organs or body cavities. It is a phenomenon most commonly witnessed in sepsis, and less frequently in autoimmune diseases, differentiation syndrome, engraftment syndrome, hemophagocytic lymphohistiocytosis, the ovarian hyperstimulation syndrome, viral hemorrhagic fevers, and snakebite and ricin poisoning. Pharmaceuticals, including the chemotherapy medications gemcitabine and tagraxofusp, as well as certain interleukins and monoclonal antibodies, can also cause capillary leaks. These conditions and factors are sources of secondary capillary leak syndrome.
Hydroxyethyl starch (HES/HAES), sold under the brand name Voluven among others, is a nonionic starch derivative, used as a volume expander in intravenous therapy. The use of HES on critically ill patients is associated with an increased risk of death and kidney problems.
The Surviving Sepsis Campaign (SSC) is a global initiative to bring together professional organizations in reducing mortality from sepsis. The purpose of the SSC is to create an international collaborative effort to improve the treatment of sepsis and reduce the high mortality rate associated with the condition. The Surviving Sepsis Campaign and the Institute for Healthcare Improvement have teamed up to achieve a 25 percent reduction in sepsis mortality by 2009. The guidelines were last updated in 2016.
Early goal-directed therapy was introduced by Emanuel P. Rivers in The New England Journal of Medicine in 2001 and is a technique used in critical care medicine involving intensive monitoring and aggressive management of perioperative hemodynamics in patients with a high risk of morbidity and mortality. In cardiac surgery, goal directed therapy (GDT) has proved effective when commenced after surgery. The combination of GDT and Point-of-Care Testing has demonstrated a marked decrease in mortality for patients undergoing congenital heart surgery. Furthermore, a reduction in morbidity and mortality has been associated with GDT techniques when used in conjunction with an electronic medical record.
Critical illness-related corticosteroid insufficiency is a form of adrenal insufficiency in critically ill patients who have blood corticosteroid levels which are inadequate for the severe stress response they experience. Combined with decreased glucocorticoid receptor sensitivity and tissue response to corticosteroids, this adrenal insufficiency constitutes a negative prognostic factor for intensive care patients.
The Sepsis Six is the name given to a bundle of medical therapies designed to reduce mortality in patients with sepsis.
Vasodilatory shock, vasogenic shock, or vasoplegic shock is a medical emergency belonging to shock along with cardiogenic shock, septic shock, allergen-induced shock and hypovolemic shock. When the blood vessels suddenly relax, it results in vasodilation. In vasodilatory shock, the blood vessels are too relaxed leading to extreme vasodilation and blood pressure drops and blood flow becomes very low. Without enough blood pressure, blood and oxygen don’t be pushed to reach the body’s organs. If vasodilatory shock lasts more than a few minutes, the lack of oxygen starts to damage the body’s organs. Vasodilatory shock like other types of shock should be treated quickly, otherwise it can cause permanent organ damage or death as a result of multiple organ dysfunction.
Septicemia... has been used... in a variety of ways... We therefore suggest that this term be eliminated from current usage.
We believe that adopting a more restrictive definition that requires further progression along the sepsis pathway may delay intervention in this highly time-dependent condition, with additional risk to patients.
We hope this editorial will clarify that the qSOFA is meant to be used to raise suspicion of sepsis and prompt further action—it is not a replacement for SIRS and is not part of the definition of sepsis.
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