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Sepsis: Pathophysiology

and Management in theICU

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Systemic inflammatory response syndromeDiagnostic criteria:

(at least 2 of the following)

1.Temperature >38 C or 90/min

3.Respiratory rate > 20 breaths/min or arterial PCO2 12,000/cmm or 10 % immature

(band) forms

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Definitions

Sepsis : SIRS as a result of infection

Severe Sepsis : Sepsis + dysfunction of 1 or more vital organs

Sepsis Induced Hypotension : SBP

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Determinants of the Sepsis Syndrome

Virulence of the organism

Inoculum of the organism

Site of Infection

Host response

Inflammatory

Anti-inflammatory

Balance

Genetic factors

Susceptibility Regulation

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1)Bacteria-

Aerobes

gram negative rods- klebsiella,serratie

- pseudomonasgram posive cocci - strepto,staph

gram negatiev cocci - meningococci

Mycobacteria

2)Viruses -flavivirus,coronaviridae

3)Rickettsia4) Fungi- candida,histoplasma,aspergillus

Common Etiology

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Pathophysiology

-Loss of hemostatic balance + endothelial dysfunction- Compromising the circulatory system, intracellularhomeostasis.

- Cellular hypoxia and apoptosis .

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Systemicinvolvement

1.Vascular System Micocirculatory shunting dueto:

1)Microthrombi

2)Endothelial cell swelling

narrowing the capillary lumen

3)Activated leukocytesadhering to endothelial cells

4)Dysfunctional RBC

(decreased deformability)

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2.Cardiac dysfunction

Myocardial contractility compromisedDiastolic dilatation of the left ventricle increasing leftventricular end diastolic volume to maintain sufficientstroke volumeRightward shift of frank starling law

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3.Endocrine dysfunction

Corticosteroids-Vasopressin-Insulin-

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Diagnostic criteria for sepsisSSC guidelines 2008

A) Infection, documented or suspected, andsome of the following:

1)General variables : Fever (38.3C), Hypothermia (core temperature 36C),

Heart rate >90 /minor > 2 SD , Tachypnea, Altered mental status, Significant

edema or positivefluid balance (20 mL/kg over 24 hrs), hyperglycemia

(plasma glucose 140

mg/dL or 7.7 mmol/L) in the absence of diabetes

2) Inflammatory variables: Leukocytosis (WBC > 12,000 /L), Leukopenia(WBC