Читать книгу Clinical Cases in Paramedicine - Группа авторов - Страница 163

RR: 30 bpm

HR: 126 bpm

BP: 100/58 mmHg

SpO₂: 90%

Blood glucose: not repeated

Temperature: 38.3 °C

GCS: 15/15

4 lead ECG: sinus tachycardia

1  What is sepsis? ‘Sepsis is characterised by a life‐threatening organ dysfunction due to a dysregulated host response to infection’ (UKST, 2019, p. 14).

2  Outline the pathophysiology of sepsis. Sepsis is when the body’s natural inflammatory immune response to a localised infection becomes systemic, setting off a chain of physiological responses that quickly become life‐threatening. It is an exaggerated response involving both the complement system (immune response) and the coagulation cascades.The body tries to keep up with the increased demand for oxygen by raising the respiratory rate (RR) to increase the level of oxygen in the blood and to oxygenate the extra blood flow through the lungs. The heart rate (HR) and stroke volume (SV) are raised, leading to an increased cardiac output (CO). Vasodilation occurs, allowing the blood vessels to transport a greater blood volume, which eventually leads to reduced preload and reduced SV. The HR increases further to compensate, resulting in tachycardia. Some patients may be on medications that mask tachycardia (e.g. betablockers).Profound vasodilation leads to a ‘relative loss’ in circulating volume and the increased permeability of the blood vessels following the release of histamine results in an ‘absolute loss’ as fluid escapes into the extravascular space. 25% of patients with septic shock present with a normal BP (cryptic shock or occult hypoperfusion) and others may present with relative hypotension (systolic BP >40 mmHg lower than normal systolic BP).In the early stages patients may be warm and flushed as vasodilation leads to an increased blood volume in the peripheries. Heat generated soon becomes lost through the skin, reducing the temperature. In the later stages, the patient begins to peripherally shut down as the body attempts to redirect the blood to its core organs, which results in a further cooling of the skin. Hypothermia/cold sepsis occurs in 10–20% of patients and is more common in elderly patients. The mortality rate for these patients is double that of those with pyrexia.

3  Which groups are most at risk of developing sepsis? Elderly patients (>75 years or frail).Young patients (under 1 year).Immunocompromised patients whose immune system is impaired by medication or illness (e.g. chemotherapy patients) or where immune function is impaired due to medical conditions (diabetes and sickle cell) or medications (immunosuppressants or steroids).Post‐surgery (within the last 6 weeks).Open wounds.Patients with indwelling medical devices (catheters or cannulas).Intravenous drug users.Pregnant women with recent history of miscarriage or termination and post‐delivery.

4  What prompts or tools are used to determine when to screen for sepsis? Guidelines used to recommend use of the modified systemic inflammatory response syndrome (SIRS) criteria, whereby patients presenting with two of more SIRS criteria with a confirmed or suspected infection were deemed to require further investigation to confirm or exclude a diagnosis of sepsis. This screening tool captured those patients presenting with ‘uncomplicated’ sepsis who were otherwise well and were at low risk for clinical deterioration. The definition of sepsis has now been updated so only those with a degree of organ dysfunction or clinical compromise are included. The SIRS criteria are no longer used as a screening tool.The red flag system was developed to be used in conjunction with the SIRS criteria as a guide to which patients needed early intervention. This was to ensure responsible antibiotic stewardship due to the sensitivity of the SIRS criteria. The red flag system is quick to apply and is used by over 90% of UK hospitals.The revised version of the National Early Warning Score (NEWS2) track and trigger system has been shown to be the most effective screening tool for predicting adverse outcomes for patients presenting with sepsis. This has now been incorporated into many systems, where screening is recommended for those with a NEWS2 of greater than 5 with identified risk factors or clinician concerns.

5  Which components of the Sepsis Six apply to the prehospital environment? Oxygen: titrate to maintain SpO2 at 94–98%.Fluids: bolus of 500 mL over 15 minutes if indicated (systolic BP <90 mmHg).Antibiotics: benzylpenicillin for meningococcal septicaemia. Refer to local guidelines regarding the use of broad‐spectrum antibiotics. Not routinely recommended.Lactate: measure lactate if indicated by local guidelines. Not routinely recommended.