sepsis Flashcards
what is sepsis?
the body’s extreme response to an infection
a life-threatening organ dysfunction caused by a dysregulated host response to infection
what causes sepsis?
chemicals released by the immune system to fight an infection cause a systemic dysregulated response that triggers changes that can damage multiple body systems
what is septic shock?
a subset of sepsis leading to profound circulatory or cellular/metabolic abnormalities which substantially increases mortality
(hypotension plus hypoperfusion plus elevated lactate)
most common sites of infection leading to sepsis?
respiratory, such as pneumonia
urinary tract;
abdominal infection;
skin – surgical wounds, lesions, ulcers
clinical phases of sepsis?
SIRS
sepsis
septic shock
risk factors for developing sepsis?
immunodeficiencies (HIV, cancer)
chronic medical conditions (diabetes, lung disease, CKD)
post-op
IVDU
infants under 1 / children / older adults 65+
what is SIRS?
systemic inflammatory response syndrome
how is SIRS defined?
a combination of 2 or more of these symptoms:
- Temperature of ≥38 ̊ C or <36 ̊ C
- Heart rate > 90 bpm
- Respiratory rate > 20 or PaCO2 < 32mmHg
- WBC >12000 or <4000 (Peddleton, 2018).
what can cause SIRS?
what is the significance of SIRS?
ischemia, inflammation, trauma, infection, or a combination of these factors
SIRS is non-specific (no known infection)
when combined with a source of infection, SIRS = sepsis.
clinical definition of sepsis?
SIRS (x2+ symptoms) + infection (confirmed or suspected)
pathophysiology of sepsis?
- sepsis occurs when chemicals released by the immune system to fight an infection cause a systemic dysregulated response that triggers changes that can damage multiple body systems
- the source of infection has left the local site → now in the circulation
- deregulated release of inflammatory mediators leading to vasodilation, increased vascular permeability, ineffective tissue oxygen delivery and coagulation pathway activation
- increase in anaerobic metabolism → lactic acid accumulation → metabolic acidosis
- deranged Na+/K+ pump → Na+and water moves into the cells → fluid shift from ECF to ICF
most common symptoms of sepsis?
Tachypnoea (99%) is the most common symptom closely followed by tachycardia (97%)
note that fever is not always present in the patient with sepsis
acronym associated with recognising sepsis?
TIME
Temperature - higher or lower than normal
Infection - may have signs or symptoms
Mental decline - confused, sleepy, difficult to rouse
Extremely ill - pt feels severe pain or discomfort, feels they might die
clinical manifestations of septic shock?
persistent hypotension requiring vasopressors to maintain, not responding to fluid replacement
cardiovascular dysfunction and haemodynamic instability
serum lactate greater than 2 mmol/L despite adequate volume resuscitation
what is qSOFA?
quick Sequential Organ Failure Assessment Score
what is a qSOFA score of more than 2 correlated with?
in-hospital mortality greater than 10%
what things score a point on the qSofa scale?
Low blood pressure (SBP ≤ 100 mmHg)
High respiratory rate (≥ 22 breaths/min)
Altered mentation (GCS ≤ 14)
management of sepsis?
first six steps within an hour
- assessment - if pt shows signs of SIRS, request urgent medical review
- two sets of blood cultures from seperate sites +/- other cultures (urine, sputum, wound etc)
- administer antibiotics without delay
- measure lactate
- IV fluid resuscitation (rapid bolus, continue Ax)
- administer oxygen (aim for 92-96%)
- ongoing monitoring/escalation - ongoing obs, consider ICU, vasopressors
- supportive care - mechanical ventilation, insulin therapy, may need blood products, IDC, enteral feeding
management of potential complications of sepsis?
proton-pump inhibitor or histamine-2 blocker for stress ulcer prophylaxis
heparin
complications of sepsis?
Multiple Organ Dysfunction Syndrome (MODS) – progressive physiologic failure of two or more organ systems
Acute Respiratory Distress Syndrome (ARDS) –
• Damage to small blood vessels in the lungs → fluid leakage into air spaces → impaired gas exchange → hypoxia
Disseminated Intravascular Coagulation (DIC)
what is Disseminated Intravascular Coagulation (DIC)?
life-threatening complication that often manifests in response to a large amount of traumatized or dying tissue, quite common in septic shock
key mechanisms involved in DIC?
the release of tissue factor from dying tissue, leading to activation of the coagulation cascade, thrombi and micro-emboli formation especially within peripheral blood vessels →
oxygen delivery and perfusion is diminished due to alterations to blood flow, leading to or exacerbating circulatory collapse →
a peculiar effect is these patients then begin to bleed, this is due to the lack of clotting factors that remain thus normal haemostasis does not occur
fluid resus formula?
20 - 30mls per kg initially.
