Sepsis/ARDS Flashcards
Define septic shock
Sepsis + Hypotension despite fluid resucitation + Perfusion abnormalities (e.g. lactic acidosis, oliguria, mental status change)
What are the top three organ systems, ranked by prevalence, affected by sepsis?
1) Respiratory
2) Cardiac
3) Renal
Are septic patients more likely to be hypercoaguable or hypocoaguable?
Hypercoaguable
Arrange the following terms into a mechanism order:
D-dimer Plasmin Fibrin Plasminogen Fibrinogen
Thrombosis leads to clot formation. Thrombin activates fibrinogen to fibrin which can form the basic scaffolding of a clot. Fibrin polymers link at a D-attachment site with other polymers. When the clot is to be broken down, plasminogen is activated to plasmin (e.g. by tPA). Plasmin then breaks down the fibrin polymers into fibrin degradation products (FDPs) which are smaller than fibrin. However, the D-dimer attachment remains and these small FDP dimers can be detected in the blood. Elevated D-dimer indicates activation of clot system (thrombosis) or DIC.
In sepsis, is the endothelium more or less responsive to endothelium-derived vasodilators?
More responsive
During what time frame should adequate antibiotics be started after sepsis is recognized in a patient?
Within one hour (although ASAP is best)
In sepsis early-goal directed therapy, what are the accepted ranges for the following values and in what order are they achieved?
MAP
SvO2
CVP
Hct
CVP 8-12mmHg (if not then crystalloid or colloid)
MAP 65-90mmHg (if not then vasoactive agents)
Hct >30% (if not then transfuse)
SvO2 >70% (if not then give inotropic agents)
A large study evaluated the benefit of dopamine vs norepinephrine for the treatment of hypotension in septic shock. Which is preferred and for what reason?
Norepinephrine preferred because of fewer adverse events (i.e. tachycardia, arrhythmias, and less need for additional vasopressors)
What are the criteria for ARDS?
Hint: 4
(i) Acute onset
(ii) Bilateral opacities on CXR
(iii) Relative hypoxemia
(iv)
What are 4 of the most common causes of ARDS?
Aspiration
Pneumonia
Sepsis
Trauma
Physiologically, what causes the hypoxia seen in ARDS?
What happens to pulmonary artery pressure and heart function?
V/Q mismatch
Pulmonary artery hypertension leading to right-heart failure
You’re managing a patient with ARDS. Based on the primary literature, do you prefer to be liberal or conservative when resuscitating with fluids?
Conservative
Trial demonstrated that conservative fluid management scheme led to better oxygenation and shorter length of ventilation and ICU stay, but no difference in mortality
What is the theory behind limiting the stretch of the lungs in ARDS?
By limiting lung stretch one is reducing the release of pro-inflammatory cytokines (e.g. IL-6) which could promote inflammation and worsen the physiologic response.
What is a preferred strategy in ARDS management, permissive hyperoxia or permissive hypercapnia?
What are some reasons why?
Permissive hypercapnia (reduce chances of oxygen toxicity from free radicals which can promote hyalinization, inflammation, and edema of the lung parenchyma)
Permissive hypercapnia is thought to reduce ventilator associated lung injury and limits tidal volumes
What was the ARDS NIH Network study and what did it add to the management algorithm of ARDS?
Explored the use of lower TV (6 mL/kg for ideal weight based on height) compared to standard ventilation techniques.
The trial was ended prematurely because of the survival benefit of lower TV
