1. Infection, Nosocomial
infection, SIRS, MODS
DR. MD. SHERAJUL ISLAM
FCPS (SURGERY)
CONSULTANT(SURGERY)
PABNA MEDICAL COLLEGE HOSPITAL

2. 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

3. 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

4. Metabolic:
Disseminated disease:
i) Malnutrition
(including obesity)
Cancer
ii) Diabetes
ii) Acquired
immunodeficiency syndrome
(AIDS)
iii)
Uraemia
Iatrogenic:
iv) Jaundice
i) Radiotherapy
Chemotherapy
i)
ii)
iii) Steroids

5. 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

6. Surgical Infections
A surgical infection is an Infection that is
unlikely to respond to nonsurgical
treatment or occurs in an operated site.
.

7. Examples of 1st group
appendicitis , empyema, gas gangrene, and
most abscess.
Examples of 2nd group
Wound infections or SSIs

8. 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.

10. Classification
1. Incisional SSI
2. Organ / Space SSI

11. 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

12. 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

13. 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

14. 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

15. 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’

16. Risk factors for increased risk of wound
infection
1. Malnutrition
3.Immunosuppression
i) obesity
weight loss
2. Metabolic disease
Diabetes
Uraemia
Jaundice
ii)
ii) AIDS
i)
ii)
iii)
i) Cancer
Steroids
iii)
iv) Chemotherapy
v) Radiotherapy
4. Colonisation and

17. 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

18. 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).

19. 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

20. Nosocomial infection (cont’)
Source of infection
1. Hospital personnel
2. Operation theatre & ward
3. Patient
A) Exogenous source
----------- B) Endogenous source

21. 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

22. 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

23. 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

24. C) Protection of susceptible patients by
isolation in a side room

25. More common in:
• Diabetics
• Immunosuppressed pt
• Patient on steroid therapy
• Patient on life supporting machine
• Instrumentation
• Pt on artificial prosthesis

26. 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

27. Management:
• Antibiotics.
• Isolation
• Blood, urine, pus for C/S
• Blood transfusion, Plasma or albumin
therapy
• Ventilator support

28. 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

29. Cause:
• Infection
• Multiple trauma
• Burn
• Pancreatitis

30. Pathogenesis:
•
Primary insult ( infection, trauma or surgery,
burn,pancreatitis)
•
Compounding insult
•
•
•
•
•
•
•
Hypoxia
Hypovolumia
Nosocomial infection
Bacterial and endotoxin leakage from GIT
Malnutrition
Hyperthermia
Hyperglycaemia

31. 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

32. Sepsis
• Sepsis is defined as the systemic manifestation of SIRS, with a
documented infection

33. 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]

34. 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.

35. Pathogenesis:
•
Primary insult
•
Compounding insult
•
SIRS
•
MODS

36. MODS
• cellular dysoxia (i.e. dysfunctional mitochodria)
• microvascular occlusion or shunting
• tissue hypoxia
• cellular dysfunction and or death .

37. Management:
• Primary insult --------------------- unavoidable
• Compounding insult ------------------- preventable or treatable.
• SIRS --------------------------------------- manageable
• MODS is fatal

38. Multiple system organ failure (MSOF)
• Multiple system organ failure (MSOF) is the end-stage of
uncontrolled MODS.