NOSOCOMIAL INFECTIONS

BHUTH S1 LECTURE

Dr. WINA FM

NOSOCOMIAL INFECTIONS

​

• INTRODUCTION
• CLINICAL TYPES
• SOURCES
• MICROBIOLOGY
• DIAGNOSIS
• INVESTIGATION OF OUTBREAK
• TREATMENT
• PREVENTION
• CONCLUSION

​

DEFINITION

• Hospital Acquired Infection.

​

• The transfer of pathogens to an ordinarily uninfected patient with the source coming from the hospital.

STATEMENT OF SURGICAL IMPORTANCE

• Surgical wound infections and nosocomial infections in the surgical patient affects management adversely:
• Patients morbidity & delays recovery;
• Hospital stay;
• Increased Cost;
• Development of resistant strains;
• Surgical mortality
• Drain hospital resources
• Surgeon Embarrassment, fatigue

​

CLINICAL TYPES

• Wound infection (45%)
• RTI (20%)
• UTI (15%)
• Blood Infection (HIV, Hepatitis.)
• G.I infection (Diarrhoeal diseases)

​

SOURCES

1. Endogenous (Auto) Infection - (Skin, Droplet, Feco-oral).

​

• Exogenous (Cross) Pathogens - (Ward, Theatre, Personnel).

MICROBIOLOGY�

1. G +ves -a. Staph aureus (Nares, Hand, Perineum).

-b. Strept pyogenes (mainly throat)

2. G –ve -a. E.Coli (Gut)

-b. Proteus (Gut)

-c. Pseudomonas (Gut; Ant. Urethra).

-d. Klebs (Gut).

​

3. Anaerobes - Clostridia spp. (C. tetani; C. perfringes) mainly large gut.

​

​

DIAGNOSIS OF N.S WOUND INFECTION�

1. Wound infection
2. Place of contamination
3. Source

1. Wound infection
1. Symptoms -i. General (malaise, fever ±rigors; vomiting; headache; loss of appetite; etc).

​

-ii. Local (pain; swelling; wound discharge; limitation of movement).

2. Signs -i. Early (Hyperaemia; warmth;

wound swelling; pink sign; frank pus).

​

-ii. Late (Cellulitis; lymphadenitis;

wound discharge; wound gangrene).

​

3. Ancillary investigation -i. Aspirate m/c/s

​

-ii. Wound swab m/c/s

​

-iii. Wound edge biopsy.

2. Place of contamination

1. Theatre
2. Ward

3. Source of infection

1. Theatre -i. Personnel (Surgeons; Theatre Nurses, Anaesthetists, Observers.).

​

-ii. Breach in Aseptic Technique (Torn gloves; improper sterilization; prolonged surgery; droplet infection; sweat drops; contaminated antiseptic solution, etc).

​

-iii. Air Borne (Indiscriminate traffic; poor air conditioning & exhaust systems; dusty environment).

2. Ward -i. Patients (Self; patient to patient contact).

-ii. Staff

​

-iii. Formites (Sharing common baths; sink; beddings; dressings & instruments).

​

-iv. IV line / canula

​

-v. Drains / Catheter.

INVESTIGATION OF OUTBREAK

• Principles

​

1. Identify the organism & subtype;

​

• Determine the source (Endogenous or Exogenous).

​

a. If Auto infection, take swabs (Nares, throat, urethra, rectum).

​

b. If Cross infection, identify place (ward or theatre).

​

27. If ward, determine origin (staff, other patients; equipment / instruments). eg:

​

• Open all wounds & take swabs;

​

• Take swabs from Nares, hand, throat, rectum of patients and staff.

​

• Take swabs from suspected equipments, antiseptic solutions, sterilization system, ventilation units (dust or bacterial filters).

​

• Observe technique of wound dressing.

bb. If Theatre:

​

• Take swabs from surgeons, theatre / anaesthetists.

​

• Take swabs from theatre equipment, ventilation units, sterilization system, antiseptic solution.

​

• Observe scrubbing procedure & aseptic conduct in theatre operation.

TREATMENT

• Principles:
• Open & drain all suspected wounds
• Obtain specimen for antibiogram studies
• Commence appropriate antibiotics (initially from previous experience, later from sensitivity).
• Identify, remove and treat causes (patients, staff, equipment).
• Report cases to Surveillance Team comprising A Surgeon, A member of Theatre staff, A Senior Microbiologist and an Administrative staff.
• Alerts hospital community;
• Offers advice (e.g. closure of theatre; evacuation of ward; discontinuation of a particular antibiotic etc).

PREVENTION: SEVERAL LEVELS

i. THEATRE:

a. Design: Location & Architecture

​

b. Conduct of staff & observers:

- Bar people with overt infection or open wounds.

​

- reduce movement intra-op

​

- Proper scrubbing, gowning, mask & boots, gloves, preferably doubled.

​

- Minimize duration of operation.

3. Adequate patient preparation:

- No personnel effects;

- Shave patient in theatre;

- Proper skin prep

- Prophylactic perioperative antibiotics.

​

4. Care of theatre & equipment:

- Regular theatre fumigation (formalin)

- Proper instrument sterilization / implants (prosthesis).

ii. WARD:

a. Design: Avoid overcrowding

: Cubicles > Open

​

b. Dressing method: Pack system > Drum method.

- Better done in Special Dressing Room > Open Ward.

- No touch technique: Sterile instruments only.

​

c. Care of Ward:

- Proper ventilation

- Prompt disposal of contaminated material and wound dressings;

- Change bed sheet daily or PRN;

- Change blankets x 1/52

- Change window blinds x 1/12

4. Conduct of staff:

- Exclude staff with open wounds or overt infection.

- Change gloves and wash hands in between patients.

​

5. Isolation & reverse isolation

- Isolate contagious cases (TB, Measles, Smallpox, Chicken pox)

- Reverse isolation for immuno compromised patients; (Transplant patients; prolonged steroid therapy; agranulocytosis; leucopenia; agamma -, hypogamma -, dsygamma – globulinaemia) severe burns, debilitating illness.

6. Prevention of Nosocomial Pneumonia (RTI):

- Early ambulation

- Adequate pre- & post-op chest physio.

​

7. Prevention of Nosocomial UTI:

- Clean catch urine specimen (MSU)

- Safe catheterization

- Closed method of drainage > spigot drainage.

CONCLUSION

​

• N.I continues to increase the morbidity and mortality of surgical patients.

​

• Identification and controlled of the causative factors is the most effective and preventive measure that can be successfully implemented.