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: 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

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 1 st group appendicitis, empyema, gas gangrene, and most abscess. Examples of 2 nd 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 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

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 A) Exogenous source 3.Patient ----------- 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 10 9 or < 4 x 10 9

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. 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.