Surgical Antibiotic Prophylaxis 20112012

UNIVERSITI KEBANGSAAN MALAYSIA

SEM II 2011/2012

NF4045 FARMASI KLINIKAL & TERAPEUTIK II

SURGICAL ANTIBIOTIC PROPHYLAXIS

ASSOC. PROF. DR AHMAD FUAD SHAMSUDDIN

23 FEB 2012

LECTURE OBJECTIVES

After the lecture, students are expected to understand the following;

The importance of antibiotic prophylaxis in surgery

The pathogenesis of complications due to surgical infection

Risk factors for surgical infection

Types of surgical site bacteria

Classification of surgical procedures

Approach to the use of antibiotics in surgery

Pharmacy-managed Antibiotics Programme

ACT III Scene I

Pharmacy-managed Antibiotics Programme

Questions to ask;

1. How do we start the programme?

- Study current practice- Retrospective - Prospective- Identify the wards or the

group of patients- Be aware of your strength and

weaknessesa.Knowledgeb.Skillsc. Staff

2. Can we make a difference to the current practice?

- Incidence of post-surgical infections

- Cost-benefit- Overall cost

3. Is it beneficial to the patient?- Overall clinical outcome

Introduction to Surgical Site Infection

- Surgical site infection, SSI (surgical wound infection) is the most common surgical complication

- Rate of infection due to surgical site complication is 6% while post-discharge data shows infection rate due to surgical site complication 50% (Weigelt et al 1992)

- SSI is the third most common nosocomial infection after UTI, and pneumonia (Bergogne-Berezin 1999)

- SSI increases 2x doctor’s time, and 5x nursing time in treatment of patient (Noel et al 1997)

- SSI hospital stay

- Study in Canada revealed increase in length of hospital stay by 19.5 days compared to uninfected patients (Taylor et al 1995)

- SSI cost

- Antibiotic use involving surgery amounts to 30% of antibiotic use in hospitals

- In the US the cost of treating an infection amounted to RM1520 – 28500

(Sands et al 1999)

- In Canada treatment of each SSI amounted to RM14960 (Zoutman et al 1998)

- Generally hospital treatment cost by 50% (McGowan 1991)

- SSI causes discomfort and morbidity

- 0.62 – 1.9% of SSI patients die (Roy & Perl 1997)

What about the general Malaysian practice?

The Pathogenesis Of Complications Due To Surgical Infection

Epithelial surface of the body separates the body’s sterile contents from the outside environment which is inundated with bacteria

Outside environment includes the luminal contents and so forth.

Epithelial layer includes the skin,

conjunctiva, tymphanic membrane, mucosal layers of the respiratory, gastrointestinal, and genitourinary tract

Penetration of bacteria across the border due to trauma or surgery may cause infection.

The occurrence of infection depends on the ability of the body’s defence system to annihilate the elements that managed to bypass this border.

The defence mechanisms include the antibodies, phagocytic (neutrophils, monocytes, and macrophages), and complementary cells

Both the antibiotics and the body’s immune system can sterilise the contamination of the internal system by the external elements

Bacteria need to exist at the wound site before any infection could occur

The statement should read;

- the type of microorganism, and the magnitude of inoculum have a bearing on the occurrence of infection

- magnitude of inoculum for infection to occur is 105 organisme at the surgical site

The condition surrounding the wound will influence the minimal infecting dose

- presence of foreign bodies,

trauma, haematoma inoculum

Risk Factors for SSI

1. Age > 60 years

2. Prematurity

3. Obesity

4. Malnutrition

5. Underlying diseases

6. Shock

7. Diabetes mellitus

8. Leukaemia

9. Immunocompromised patients

10. Hepatic failure

11. Renal failure

12. Use of steroids, antimetabolites and other anticancer drugs

13. Blood transfusion

14. Personal net skills

15. Long surgery

16. Prolonged hospital stay

Types of Pathogens Found in Various Parts of the Body

Skin : S. aureus, S. epidermidis

Nose : S. aureus, Pneumococcus sp., Meningococcus sp.

Mouth /pharynx : Streptococci (, ),

Pneumococcus sp. E.coli,(oral)Bacteroides sp., Fusobacterium sp. , Peptostreptococci sp.

Upper Respiratory : Pneumococcus sp.tract H. influenzae

Biliary tract : E. coli, Klesiella sp., Proteus sp., Clostridia sp.

Urinary tract : E. coli, Klesiella sp., Proteus

sp., Enterobacter sp.

Colon : E.coli, Klebsiella sp., Enterobacter sp., Clostridia

sp., Bacteroides spp., Peptostreptococci sp.

Vagina : Streptococci sp., Staphylococci sp., E. coli, Bacteroides spp., Gonococcus sp., Peptostreptococci sp.

Classification of Surgical Wound and its Risk of Infection

Wound Rate CriteriaTypes of SSI

Clean < 2% Non-traumatic; Respiratory, alimentary, biliary, and genitourinary tracts not operated; No inflammation; No break in technique*; elective case*

Clean- <10% Surgery on the respiratory, Contaminated alimentary, biliary, and genitourinary tracts without significant spillage & without infected bile or urine ; Minor break in technique

Contaminated 20% Major spillage* from alimentary tract, entry into biliary or genitourinary

Tracts with in the presence of bile or contaminated urine, presence of

Non-purulent inflammation

Dirty 40% Faecal contamination; presence of pus and necrotic tissue ; presence of

known infection

[NATIONAL RESEARCH COUNCIL Classification (Page et al 1993);[Jenkins & Pedlar 1999 in Clinical Pharmacy & Therapeutics]

* Definitions

Spillage

- Spread or spillage of organ contents (e.g. intenstine), cysts, abcess in surgical sites

Break in Technique

- Technical disturbances or breakdown during surgical procedure

- Personnel fault e.g. touching part of colleague’s body (e.g. hand); or parts of surgical table cloth;

- Surgical procedure continued without disinfection

Elective Surgery

- Non-emergency surgery

- OT date given e.g. surgery to thyroid gland

Approach to Antibiotic Use in Surgery

Prophylaxis

Administration of antibiotic(s) in the absence of infection but the chances of infection occurring is high e.g. in certain surgical procedures

Therapeutic Use

Antibiotic(s) administered in the presence of infection

In surgery;

Administration of antibiotic(s) when contamination during surgical procedure happens e.g. spillage of organ contents

Importance of Surgical Antibiotic Prophylaxis

SSI

SSI complications

chances of nosocomial infections

Hospital stay

CostWhen is Surgical Antibiotic Prophylaxis necessary?

i. surgical procedures with high risk of infection occurring;

ii. presence of infection will worsen patient’s condition;

iii. immunocompromised patients

Principles in the Prophylactic Use of Antibiotics in Surgery

Administration of antibiotics at the right time during the surgical procedure can prevent or reduce the magnitude of an infection which can lead to other surgical complications

The factors listed are considered in surgical antibiotic prophylaxis

i. Risk of infectionii. Choice of antibiotic regimeniii. Determination of time of administration

(wrt surgical procedure)iv. Route of administration

i. Risk of Infection in Surgery

Risk of infection dependable on;

a. Host Factor

(Refer above notes)

b. Pathogen

- Types of microorganisms at surgical site

- Presence of underlying infection

c. Technique and skills of personnel

- dependable on surgical skills of personnel and surgical procedure

- it is found that high incidence of infection in hospital with less surgery performed

- long surgery increases risk of infection

ii.Choice of antibiotic regimen

- Based on type of pathogens present

- Based on antibiotic’s spectrum of reaction

Broad vs narrow spectrum

- Antibiotic’s toxicity

- Antibiotic’s ability to penetrate tissue

- Half-life of antibiotics

- Cost-effectiveness

The choice of antibiotics or antibiotic regimen should be based on proven clinical effectiveness

iii.Determination of time of administration

- Too early administration of antibiotics can lead to

tissue [ ] during surgical procedure

- Prophylaxis should not be given > 24 hours before procedure

- The best time would be immediately before

- One dose sufficient

iv.Route of Administration

a. IV Administration

Antibiotic given during induction of anaesthesia

b. IM administration

Antibiotic given together with premedication~ 1-2 hours before procedure

c. Rectal administration

Suppository inserted 2-4 hours before procedure

d. Topical administration

Not recommended except in ophthalmic operation & burn wounds

Route & time of antibiotic administration should be planned so that tissue antibiotic [ ] is at maximum during and after surgery

Antibiotic prophylaxis is useful in the following procedures:

1. Gynaecology

a. Emergency Caesarean section

b. Hysterectomy

2. Orthopaedic surgery

a. Major Art0hroplasty of joints

b. Open reduction of fracture

c.Lower limb amputation

3. General surgery

a. Gastro-oesophageal

e.g. bleeding gastric/duodenal, gastric resection/bypass, benign/malignantstricture

b. Biliary

Cholecystectomy

- age > 60 years - hx cholecystitis

Exploration of bile duct

- occlusion/stricture

Pancreaticoduodenectomy

- carsinoma

c. Colorectal Surgery

- resection/anastomosis of colon for benign or malignant

- Abdominoperineal resection for rectal carsinoma

d. Appendicectomy

4. Urology

- Prostatectomy with presence contaminated urine Urin (presurgery)

- PCNL Percutaneous nephrolithotomy The removal or treatment of a kidney stones by inserting a tube through the skin and into the kidney, under a general anaesthetic.

5. ENT surgery

- surgery involving the head, neck, & oral (throat) region

Antibiotic prophylaxis not indicated in the following:

Thyroid & parathyroid surgery

Mastectomy

Laparatomy for adhesiolysis

Herniorraphy/hernioplasty/hernia repair - procedure for correcting hernias

Minor wounds & lacerations

Lumpectomy

Risk in Antibiotic Prohylaxis in Surgery

ii. Direct effect to patients

For patients who do not require prophylaxis;

- exposure to dose-related toxicity

- drug interaction

- idiosyncratic reaction

ii. Effects to Hospital Bacterial Ecology

Extensive use of antibiotics will result in the ecological pressure – production of resistant strains

Will worsen therapeutic use of antibiotics

Benefits

i. The right patients will be safe from infection

ii. For others, transfer of bacteria will be prevented