Download Infection, Nosocomial infection, SIRS, Sepsis

Infection, Nosocomial infection, SIRS,
MODS
DR. MD. SHERAJUL ISLAM
FCPS (SURGERY)
CONSULTANT(SURGERY)
PABNA MEDICAL COLLEGE HOSPITAL
Micro-organisms are normally prevented from
causing infection in tissues by intact epithelial
surfaces. These are broken down in trauma and by
surgery.
Protective mechanism can be divided into:
• Mechanical barriers
• Chemical: low gastric pH
• Humoral: antibodies, complement and opsonins
• Cellular: phagocytic cells, macrophages
polymorphonuclear cells and killer lymphocytes
Infection
Invasion of microorganisms their multiplication and creation of
adverse host response by breakdown of local and systemic
host defenses.
Causes of reduced host resistance to infection
1. Metabolic
2. Disseminated disease
3. Iatrogenic
Metabolic:
i) Malnutrition
(including obesity)
ii) Diabetes
iii) Uraemia
iv) Jaundice
Disseminated disease:
i) Cancer
ii) Acquired immunodeficiency
syndrome (AIDS)
Iatrogenic:
i) Radiotherapy
ii) Chemotherapy
iii) Steroids
Classification of sources of infection
■ Primary:
acquired from a community or endogenous
source
■ Secondary or exogenous (HAI):
acquired from the operating theatre or the ward
or from contamination at or after surgery
Surgical Infections
A surgical infection is an Infection that is
unlikely to respond to nonsurgical
treatment or occurs in an operated site.
.
Examples of 1st group
appendicitis , empyema, gas gangrene, and
most abscess.
Examples of 2nd group
Wound infections or SSIs
Surgical Site Infection (SSI)
Surgical site infection (SSI) is infection at
the site of an operation either at the site
of incision or in the organ or body cavity
that are manipulated during operation.
Classification
1. Incisional SSI
2. Organ / Space SSI
Classification
1. Incisional SSI
i) Superficial incisional
SSI: only the skin or
subcutaneous tissue of the
incision
ii) Deep incisional SSI :
deep tissues (i.e.
fascial and muscle layers)
2. Organ / Space SSI :
involving any part of the
anatomy(i.e.organ/space)
, other than the incision,
opened or manipulated
during the surgical
procedure
Wound infection
The infection of a wound can be defined as
the invasion of organisms through tissues
following a breakdown of local and systemic
host defences, leading to cellulitis,
lymphangitis, abscess and bacteraemia
A major SSI or major wound infection is defined
as a wound that either discharges significant
quantities of pus spontaneously or needs a
secondary procedure to drain it.
The patient may have systemic signs such as
tachycardia, pyrexia and a raised white count or
delay in return home
Minor wound infections may discharge pus
or infected serous fluid but should not be
associated with excessive discomfort,
systemic signs or delay in return home
Factors that determine whether
a wound will become
infected or not
1. Host response
2. Virulence and inoculum of infective agent
3. Vascularity and health of tissue being
invaded (local ischaemia as well as systemic
shock)
4. Presence of dead or foreign tissue
5. Presence of antibiotics during the ‘decisive
period’
Risk factors for increased risk of wound infection
1. Malnutrition
i) obesity
ii) weight loss
2. Metabolic disease
i) Diabetes
ii) Uraemia
iii) Jaundice
3.Immunosuppression
i) Cancer
ii) AIDS
iii) Steroids
iv) Chemotherapy
v) Radiotherapy
4. Colonisation and
translocation in the
gastrointestinal tract
Risk factors for increased risk of wound infection
(Cont’)
5. Poor perfusion
i) Systemic shock
ii) Local ischaemia
6. Foreign body /material
7. Poor surgical technique
8. i) Dead space
ii) Haematoma
Nosocomial infection
•Acquired infection originating in a
patient while in a hospital or other
health care facility is known as
nosocomial infection. Also known as
health care-associated infection (HAI) or
Hospital Acquired Infection (HAI).
Nosocomial infection (Cont’)
There are four main groups:
•Respiratory infections (including
ventilator-associated pneumonia)
•Urinary tract infections (mostly related
to urinary catheters)
•Bacteraemia (mostly related to
indwelling vascular catheters)
•SSIs
Nosocomial infection (cont’)
Source of infection
1. Hospital personnel
2. Operation theatre & ward
3. Patient
A) Exogenous source
----------- B) Endogenous source
Prevention of Nosocomial infection
A) Reducing the sources of pathogens:
B) Restricting the transmission:
C) Protection of susceptible patients by
isolation in a side room
A) Reducing the sources of pathogens:
1. Detection of carriers, their isolation and treatment.
2. Hospital staff those who are suffering from skin
disease/sore throat/diarrhoea/dysentery should be
kept away from work until completely cured.
3. Barrier nursing
4. Task nursinng
B) Restricting the transmission:
1. Hand washing
2. Adoption of effective aseptic techniques
3. Adoption of proper sterilization and
disinfection procedures
4. Droplet infection control by use of face
masks, spacing, prevention of overcrowding
,ensuring ventilation etc.
5. Dust control
C) Protection of susceptible patients by
isolation in a side room
More common in:
•Diabetics
•Immunosuppressed pt
•Patient on steroid therapy
•Patient on life supporting machine
•Instrumentation
•Pt on artificial prosthesis
Organisms:
• Hospital acquired wound infection: S. Aureus is the
commonest
Others-Pseudomonas, Klebsiella, E. coli, Proteus.
• Hospital acquired respiratory tract infection: S.
Pneumoniae, Haemophilus, Herpes, Varicella,
Aspergillus, Pneumocystis carini
• Hospital acquired urinary tract infection: Klebsiella
is the commonest
Management:
•Antibiotics.
•Isolation
•Blood, urine, pus for C/S
•Blood transfusion, Plasma or albumin
therapy
•Ventilator support
SIRS:
• Systemic inflammatory response syndrome is the
body’s systemic response to infection or
inflammation characterized by any two of :
• Hyperthermia (> 38°C) or hypothermia (< 36°C)
• Tachycardia (> 90/ min, no β-blockers) or tachypnoea (> 20/
min)
• White cell count > 12 x 109 or < 4 x 109
Cause:
• Infection
• Multiple trauma
• Burn
• Pancreatitis
Pathogenesis:
•
Primary insult ( infection, trauma or surgery,
burn,pancreatitis)
•
Compounding insult
•
•
•
•
•
•
•
Hypoxia
Hypovolumia
Nosocomial infection
Bacterial and endotoxin leakage from GIT
Malnutrition
Hyperthermia
Hyperglycaemia
SIRS
• Increased cytokine production
• Failure to localize cytokines
• Abnormal NO production
• Contact, coagulation and complement activation
• Abnormal arachidonic acid metabolism
• Neutrophil sequestration and degranulation
• Free radical production
Sepsis
• Sepsis is defined as the systemic manifestation of SIRS, with a
documented infection
Severe sepsis or sepsis syndrome
• is sepsis with evidence of one or more organ failures
• [Respiratory (acute respiratory distress syndrome),
• Cardiovascular (septic shock follows compromise of cardiac function and fall in
peripheral vascular resistance),
• Renal (usually acute tubular necrosis),
• Hepatic,
• blood coagulation systems or central nervous system]
MODS :
Multiple organ dysfunction syndrome is defined as tissue damage in organs distal
to the origin of original injury, is the clinical manifestation of systemic inflammatory
response syndrome.
Pathogenesis:
•
Primary insult
•
Compounding insult
•
SIRS
•
MODS
MODS
• cellular dysoxia (i.e. dysfunctional mitochodria)
• microvascular occlusion or shunting
• tissue hypoxia
• cellular dysfunction and or death .
Management:
• Primary insult --------------------- unavoidable
• Compounding insult ------------------- preventable or treatable.
• SIRS --------------------------------------- manageable
• MODS is fatal
Multiple system organ failure (MSOF)
• Multiple system organ failure (MSOF) is the end-stage of
uncontrolled MODS.