Sepsis Is A Systemic Response To Bactereamia Biology Essay

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Sepsis is a systemic response to bactereamia.When bactereamia produces changes in circulation such that tissue perfusion is critically reduced; septic shock occurs.It affects one or more organs in the body system (Dellinger et al). Bacteria cause 90% cases of sepsis. They are two types, gram negative and gram positive. Escherichia coli, Klebsiella, Enterobactor, Pseudomonas aeruginosa, Serratia, Proteus and Bacteroides fragilis are the gram-negative bacteria. Staphylococcus aureus, Streptococcus pneumonia, Alpha and beta-hemolytic streptococci are the gram-positive bacteria (Edwards 2001).Gram-negative bacterial infection causes most cases of sepsis. Viruses or fungi can also cause sepsis, particularly Candida spp (Cohen et al 2004).

In previously, healthy adults consider the chest, urinary tract or biliary trees as the most common sources of infection. In a hospitalized patient the source may be a wound, an indwelling urinary catheter or intravenous catheter. In a patient who is known to abuse intravenous drugs, septicemia may caused by different organisms. Patients with sepsis are acutely ill. Prompt assessment and treatment is vital. The signs and symptoms includes; hyperthermia or hypothermia, sweating, headache, muscle pain.

The surviving sepsis campaign (formed in2002) is an international collaboration to improve the diagnosis, management and treatment of sepsis. The main aims of the campaign are:

Improve the care of patient with sepsis and septic shock

Make diagnosis of severe sepsis is less than two hours from the time of admission to emergency department.

Reduction of mortality rate by 25percent in five years following the publication of evidence-based guidelines in 2004(Dellinger et al2004).

It is important that nurses are aware of the aims of Surviving Sepsis Campaign so, we can help to achieve the goal. We have an important role to identify the first signs of sepsis. It helps to reduce the risk of organ dysfunction or failure (Ahrens and Tuggle 2004).Some of the patients who admitted in hospitals develops infection during their stay (DH2003). Any system in the body can affect the infection. The most common sources of infection that can lead to sepsis are: respiratory tract infection, urinary tract infection, skin infection, meningitis, infective endicarditis, intra-abdominal infection, osteomyelitis, pelvic inflammatory disease and sexually transmitted disease.

Many organ systems may affect during the sepsis syndrome.

Respiratory system: As the effects of of sepsis progress, acute respiratory distress syndrome (ARDS) may occur. During sepsis, there is a decrease in the performance of the ventillatory muscles, which leads to hypercapneic ventillatory failure and respiratory arrest These happens when metabolic demands on the ventillatory muscles.Tachypnoea,hypoxia and respiratory alkalosis are associated with the early onset of ARDS, followed after 48 hours by pulmonary infiltrates and respiratory failure (Mortelliti&Manning). Sepsis leads to an increase in lung permeability, the sequestration of polymorphonuclear neutrophils and respiratory failure. These affect the function of respiratory system (Nagase, Uzumi&Ishii).

Cardio vascular system: The dysfunction of cardio vascular system is also observed in patients with sepsis, where both the heart and blood vessels show hypersensitivity. An increased amount of pro-inflammatory cytokines and vasoactive substances is present during sepsis. Following the increase in pro-inflammatory cytokines, production of nitric oxide is increase in both the vascular endothelium and smooth muscle. This leads to a fall in systemic vascular resistance, thereby hypotension (Patterson&Webster).

Renal Dysfunction: Normally, the kidney regulates perfusion and glomerular filtration via auto regulation, which is dependent on the afferent and efferent arterioles.Autoregulation of the kidney, is affected during sepsis.

Coagulation system: Sepsis often associated with a disorder of coagulation secondary to the cytokine-mediated activation of the coagulation pathway. This secondary disorder, known as disseminated intravascular coagulation (DIC).It causes bleeding and micro vascular thrombi, both implicated in multiple organ failure and soft-tissue damage (Meijers&Bouma).

Diagnosis can base on the presence of fever and other abnormalities of vital signs, as well as the presence of one or more organ dysfunctions that are not the original site of infection or trauma (Ahamed). Sepsis syndrome is characterized by; alteration in body temperature regulation, tachycardia, lowered systemic vascular resistance, respiratory alkalosis, leococytosis, leucopenia and some form of organ dysfunction(Chistman, Holden and Blackhell).It does not discriminate between different ages, underlying disease, genetic background, infecting micro-organisms or sites of infection.Sepsis can occur in people who were previously healthy. The infecting organism may be a temporary defect in the host's defense. Defects may be located in specific or non-specific cellular barriers, humoral immunity barriers and physical barriers such as the skin or mucous membranes and reflexes such as cough and peristalsis (Maskin, Fountain and Spinedi et al).

The incidence of sepsis is increasing and is expected to increase approximately 1.5% per year until at least 2050(Angus et al 2001).The incidence is higher among men versus women and among non white persons versus white persons (Martin et al 2003).Prognosis in severe sepsis has multiple determents including the hosts defense mechanisms, the environment and the specific microorganisms involved. Specific risk factors for death include co morbid conditions, severity of illness and organ dysfunction. Mortality was similar for patients with infection and sepsis but increased in patient with sepsis and organ dysfunction. The number of severity of organ failures is significantly associated with outcome. Risk factor for hospital mortality were evaluated in 3608 ICU patients included in European Sepsis Study.

Clinical assessment is important in patients with sepsis. The two or more sepsis criteria are; Temperature>38or<36, respiratory rate>20/min, heart rate>90bpm, acutely altered mental status, blood glucose >7.7mmol/L in absence of diabetes, white blood cell count>12000 or <4000/L. Any patients who triggers early warning score, should be assessed initially using the ABCDE approach. This systemic approach ensures that the life threatening problems are assessed and managed in order of importance. The Resuscitation Council 2006 also recommends that clinical staff should follow ABCDE approach when assessing and treating critically ill patients. It is sensible to adopt this systemic approach to the assessment of sepsis patient (ABC of sepsis).

Airway: An assessment should be made of the patency of airway. If patient is alert and talking, there is less chance of an airway problem.

Breathing: The body's demand for oxygen rises in sepsis. As demand outstrips supply, lactic acidosis occurs. These processes combine to elevate the respiratory rate. The depth and pattern of respiratory rate should evaluate in addition to any asymmetry of chest movement. Listen for abnormal sounds include expiratory wheeze, suggesting obstruction of the lower airway and crepitating suggest the secretion, pulmonary oedema or consolidation. If a respiratory problem is identified, attention should be given to oxygen therapy and to the possible need for bronchodilators and physiotherapy. The response to therapy should be assessing repeatedly. Pulse oximetry is mandatory, and ABG and chest X-ray is helpful.

Circulation: Attention should pay to the colour of the skin, particularly peripherally. Pallor is suggestive of hypo perfusion and may suggest a low cardiac output. Heart sound should auscultate to seek murmur. Feel for the peripheral skin temperature. In decompensated sepsis, where the cardiac output begins to fall, the peripheries may appear cool. Capillary refill time is useful test of perfusion. The heart rate and rhythm should asses by palpitation of peripheral pulses.

Disability: Sepsis can produce confusion, agitation and reduced conscious level due to reduced cerebral perfusion. Fluid resuscitation can restore cerebral function. It is important to check blood sugar because; hypoglycemia can also produce these signs and is readily correctable. The conscious level can quickly asses and communicate using the AVPU scale.( A-Alert,V-responds to voice,P-responds to pain,U-unresponsive).

Exposure: The patient should be examined from head to toe seeking the source of sepsis. Consideration should be given to the patient's dignity during this assessment, and it should be recognized that exposure can cause rapid temperature loss. Therefore, it is essential to check peripheral temperature.

When treating patients with sepsis, the first hour known as the `golden` hour because the treatment given or not given during that time can have significant impact on the survival (ACS 1997).To be able to treat patients in the `golden hour` we must first be able to recognize it confidently. Studies have shown that patients admitted to intensive care unit from the wards are often not referred early enough. Sometimes receive suboptimal care, which can increase patient's mortality (McQuillan et al1998).Vincent et al 2002 suggest that some patients with sepsis are recognized late and are not treated appropriately before transfer to ICU.

In March 2004, the Surviving Sepsis Campaign produced comprehensive guidelines on the management of patients with severe sepsis. Initial treatment within one hour of diagnosis is,

Give supplemental oxygen therapy, via facemask, to achieve SpO2>94%.

Obtain blood specimen lactate, full blood count, urea and electrolytes, glucose, liver function tests, coagulation screen and blood culture two sets. Samples from sputum, urine, wound swab etc as appropriate.

Blood cultures should be taken before antibiotics are given to identify any microorganisms that may be in the blood and it should from a peripheral vein and from any invasive catheters that the patient may have in situ.Blood cultures are not always positive in patient with sepsis.

Cohen et al (2004) suggest that care should take when obtaining blood cultures to prevent them becoming contaminated and giving a false positive result.

Administer broad-spectrum antibiotics intravenously. Antibiotics should be given within one hour of diagnosis of sepsis (Dellinger et al2004). Antibiotic therapy may reduce mortality by 10-15 percent, compared with patients who had delayed antibiotic therapy.(Wheeler&Bernard1999).

Any septic patient who has a lactate level above 4mmol/L should be considered to have severe sepsis even if the blood pressure is within the normal range.

If patient is hypotensive, fluid resuscitate up to 3boluses of 500ml normal saline to maintain MAP>65/systolic 100mmhg (Trust's sepsis care pathway).

Consider catheterization to maintain fluid balance.

If the patient have signs of severe sepsis ,needs referral to ICU.Signs of severe sepsis are; Systolic blood pressure below 90mmHg or MAP below 65mmHg,lactate above 2mmol/L,urine output below0.5ml/kg/hr for 2 hours,INR above1.5,bilirubin above 34mol/L,platelets below 100mol/L,creatinine above 177mmol/L.

Infection management includes source control and prompt administration of anti infective agents that cover the microbial organisms suspected in the context of the patient's presentation.

Source control can be divided into three broad categories; debridement of infected tissue, drainage of an abscess, removal of foreign bodies.

Principles of anti infective therapy in sepsis are; obtain cultures from suspected sources of infection and prompt administration of antibiotic.

In conclusion, sepsis is a complex syndrome that results from severe infection that leads to systemic inflammation and widespread tissue damage. It can produce a range of clinical condition that rapidly results in hypotension, perfusion abnormalities, tissue hypoxia with single or multiple organ dysfunctions. Rapid and timely intervention is critical to successful treatment. Effective intervention requires rapid diagnosis and prompts and appropriate treatment including antibiotic therapy, source control, general supportive care and the patients with severe sepsis or septic shock needs cardio-pulmonary support.