surgical principles: methods of prevention of post operative infection.

1. DISCUSS THE PREVENTION OF
POST OPERATIVE INFECTION
NJOKANMA I.G.
21/03/12

2. OUTLINE
• INTRODUCTION
• HISTORICAL PERSPECTIVE
• CLASSIFICATION
• RISK FACTORS
• DIAGNOSIS
• PREVENTION
• CONCLUSION

3. INTRODUCTION
• The problem of surgical infections was almost
universal prior to the development of aseptic
surgery in the 19th century and, despite our
understanding of the nature of infections and
our ever expanding arsenal of antimicrobial
agents, post operative infection remains a
major surgical problem today.

4. INTRODUCTION
• Post-operative infections or surgical site infections
(SSIs) delay recovery, and are associated with
increased morbidity and mortality.
• They increase healthcare costs by increasing
hospital stay and the cost of therapy.

5. INTRODUCTION
• Burden-US
– ~300,000 SSIs/yr (17% of all HAI; second to UTI)
– 2%-5% of patients undergoing inpatient surgery
• Mortality
– 3 % mortality
– 2-11 times higher risk of death
– 75% of deaths among patients with SSI are directly
attributable to SSI

6. INTRODUCTION
• Length of Hospital Stay
– ~7-10 additional postoperative hospital days
• Cost
– $3000-$29,000/SSI depending on procedure &
pathogen
– Up to $10 billion annually

7. DEFINITION
• A surgical site infection is an infection that occurs
after surgery in the part of the body where the
surgery took place within 30 days of surgery or
within 1 year in the case of prosthesis.
• Infections may be
– endogenous (e.g. patient's normal flora)
– exogenous sources (e.g., personnel, the environment
or materials used for surgery).

8. Anatomical site Normal flora
Skin Staphylococcus, streptococcus
propioniobacteria
Oral cavity Above, anaerobes & gram negative rods
Nasopharynx Staph., strept., H. influenzae and anaerobes
Thorax Staph, strept, and propioniobacteria
Oesophagus
jejunum
Flora of nasopharynx + enterobacteriaecea
Large bowel Gram –ve rods, enterococci & anaerobes
Female genital
tract
Flora of large bowel, staph strept, & H.
influenzae
Urinary tract Normally sterile
Limbs Staph, strept, propioniobacteria

9. HISTORICAL PERSPECTIVE
• Hippocrates (Greek physician and surgeon, 460-
377 BC), used vinegar to irrigate open wounds
and wrapped dressings around wounds to
prevent further injury.
• Galen (Roman gladiatorial surgeon, 130-200 AD)
was first to recognize that pus from wounds
inflicted by the gladiators heralded healing (pus
bonum et laudabile ["good and commendable
pus"]).

10. HISTORICAL PERSPECTIVE
• Koch (Professor of Hygiene and Microbiology,
Berlin, 1843-1910) first recognized the role of
microbes in his 19th century postulates.
• Ignaz Sommelweis (Austrian obstetrician,
1818-1865) demonstrated a 5-fold reduction
in puerperal sepsis by hand washing.

11. HISTORICAL PERSPECTIVE
• Sterilization of instruments began in the 1880s
as did the wearing of gowns, masks, and
gloves.
• Halsted (Professor of Surgery, Johns Hopkins
University, United States, 1852-1922)
introduced rubber gloves to his scrub nurse.
• The routine use of gloves was introduces by
Halsted's student J. Bloodgood.

12. HISTORICAL PERSPECTIVE
• Penicillin first was used clinically in 1940 by
Howard Florey.

13. CLASSIFICATION
• Incisional SSIs
– Superficial
– Deep
• Organ/Space SSIs

15. Grading of Superficial SSIs
• Grade 1 induration
• Grade 2 serous discharge
• Grade 3 purulent discharge
• Grade 4 wound dehiscence

16. RISK FACTORS
• Microbial factors
– bacterial inoculums,
– virulence

18. RISK FACTORS
– Decreased host resistance can be due to systemic
factors
• Advanced age,
• malnutrition,
• obesity,
• diabetes,
• steroids,
• immunosuppressants.

19. RISK FACTORS
• Wound characteristics
– nonviable tissue in wound;
– hematoma;
– foreign material, including drains and sutures;
– dead space;
– poor skin preparation, including shaving; and
– pre-existent sepsis (local or distant).

20. RISK FACTORS
• Operation related factors
– poor surgical technique
– Antimicrobial prophylaxis
• Inappropriate choice (procedure specific)
• Improper timing (pre-incision dose)
• Inadequate dose
– lengthy operation (>2 h)

21. RISK FACTORS
– intraoperative contamination,
– infected theatre staff and instruments
– inadequate theatre ventilation;
– prolonged preoperative stay in the hospital; and
– hypothermia.

22. RISK FACTORS
• Type of procedure
Clean
Clean contaminated
Contaminated
Dirty

25. DIAGNOSIS
• HISTORY & PHYSICAL EXAMINATION
– Signs of inflammation
– Exudates
– Tacchycardia, tachypnoea
• INVESTIGATIONS
– Lab: leucocytosis, left shift, wound swabs
MCS,aspirates MCS
– Radiological: USS, CT scan, Radiographs

26. PREVENTION
• The measures are aimed at
– Removal of the sources and reservoirs of infection,
– Blocking the routes of transfer to the patients,
– Increasing the patients resistance.

27. Theatre design
• Should be on its own, a cul de sac and not a
through fare.
• Sterilization should be on its own
• Tiled from floor to ceiling
• Windows must not be opened
• Ventilation unit
• Dressings should be supplied in single packs.
• Discourage Nightingale system of nursing in the
wards.

28. PREVENTION
• Pre Operative
• Peri Operative
• Post Operative
• Surveillance

29. Pre Operative
• Correct malnutrition
• Systemic disease such as DM, kidney, liver and
congestive heart failure would need due
consideration and management.

30. Pre Operative
• Colorectal surgery patients.
– Mechanically prepare the colon (Enemas,
cathartic agents)
– Administer non-absorbable oral antimicrobial
agents in divided doses on the day before the
operation

31. Pre Operative
• Do not remove hair at the operative site unless it will interfere
with the operation; do not use razors If necessary, remove by
clipping or by use of a depilatory agent.
• Skin Prep Use appropriate antiseptic agent and technique for
skin preparation.
• Strict Asepsis.
• Maintain immediate postoperative normothermia.

32. Pre Operative
• Nasal screening and exclusion of carriers of
organisms.
• Screen preoperative blood glucose levels and
maintain tight glucose control patients undergoing
select elective procedures (e.g., arthroplasties, spinal
fusions).
• Carefully Structured theatre list.

33. Peri Operative
• Administer antimicrobial prophylaxis in
accordance with evidence based standards
and guidelines
– Administer within 30mins to 1 hour prior to
incision
– Select appropriate agents on basis of Surgical
procedure
– Most common SSI pathogens for the procedure

34. Peri Operative
• Re-dose antibiotic at the 3 hr interval in procedures
with duration >3hrs.
• Adjust antimicrobial prophylaxis dose for obese
patients.
• Use at least 50% fraction of inspired oxygen
intraoperatively and immediately postoperatively in
selected procedure(s).

36. Peri Operative
• Operating Room (OR) Traffic: Keep OR doors
closed during surgery except as needed for
passage of equipment, personnel, and the
patient.
• Meticulous surgery:
– Reduce tissue desiccation
– Pin point electrocautery

37. Peri Operative
• Clean air systems in theatres. E.g. plenum and turbulent
systems.
– 15 air changes per hour
• Use of impermeable drapes
• Change of face masks during long procedures
• Use of wound drains
– Preferably closed vacuum drain
– Not a substitute for proper haemostasis.

38. Post Operative
• Highly infectious patients can be isolated.
• Surgical Wound Dressing: Protect primary closure
incisions with sterile dressing for 24-48 hrs post-
op.
• Control blood glucose level during the immediate
post-operative period.
– Maintain post-op blood glucose level at <200mg/dL

39. PREVENTION Contd
• Policies should be established concerning patient care
responsibilities for personnel with potentially
transmissible infective illnesses.
• This should include aspects of work restrictions,
• personnel responsibility in utilizing health services, and
declaring illness.
• Policies also should direct the responsible person to
remove personnel from duty, and policy should be
established for clearance to resume work.

40. SURVEILLANCE
• Infection surveillance committee
• Feedback of surgeon specific infection rates.
• SSI Rate
– Crude, unadjusted rate
– Can lead to erroneous conclusions regarding SSI risk
by institution and/or surgeon
– NOT for reporting or inter-hospital comparisons

41. SURVEILLANCE
• NNIS(National Nosocomial Infection Study)
Risk Index Score to predict risk of acquiring
SSI
– Widely used for surveillance
– Operation-specific
– Allows monitoring of trends
– Facilitates comparison e.g. facility vs. national

42. CONCLUSION