Discuss the principles of Antibiotics use in surgical practice

byDr Kabiru Salisu

NOHD

Outline INTRODUCTION GENERAL PRINCIPLES OF ANTIBIOTICS

USE ANTIBIOTIC PROPHYLAXIS THERAPEUTIC ANTIBIOTIC USEINDISCRIMINATE USE OF ANTIBIOTICSTOXICITY OF ANTIBIOTICS CONCLUSIONS

IntroductionDefinition Antibiotics; Are products of various species

of micro-organisms including bacteria, fungi and actinomycetes that suppress growth or kill other micro-organisms

Antimicrobial (antibacterial) is a term use to including purely synthetic agents such as:SulphonamidesQuinolones

Historical Background - Louis Pasteur and Robert Koch 1877- In 1928, Alexander Fleming - Selman Waksman, in 1942- 1960’s MILES AND BURKE

Classification of antibiotics

Group/mechanism of Action1- Cell wall synthesis inhibitors(inh. Peptidoglycan synthesis)

B-lactem- Penicillins/cephalosporins others- vancomycin/ bacitracin

2- Protein synthesis inhibitors (interfere with 50s or 30s of

rRNA)

Tetracyclines , Aminoglycoside , Macrolytes,chloramphenicolclindamycin

3- Folate Antagonists (Sulphonamides) Inhibitor folate synthesis or reduction

eg sulfamethoxazole, Trimethoprim

4- QuinolonesDNA gyrase inhibitors

eg ciprofloxacin, levofloxacin

5- Nitroimidazole Eg metronidazole

6-RNA polymerase inhibitor eg Rifampicin

Mode of actionbacteriostatic bactericidalChloramphenicoltetracyclines

macrolidesSulphonamideclindamycin

penicillins,AminoglycosideCephalosporinMetronidazolequinolones

Base on Spectrum of activity- Narrow spectrum - Extended spectrum- Broad spectrum

General principles of Antibiotic use

 JUSTIFICATION : Treatment and prevention of infection is a

cardinal responsibility of the surgical team.Favorable outcome of surgeries were

recorded with appropriate use of antibioticsSSI increase mortality, morbidity, hospital

stay and cost of treatment

Selection of antibiotics Requires knowledge of - The organism's identity and its sensitivity to a

particular agent- The site of the infection (CNS, bone, GI, UT )

- The safety of the agent

- patient factors (age, preg., lactation, sys. illnesses,

hypersensitivity) - Availability, Accessibility, Affordability of the

Drug

Antibiotic prophylaxisis the use of antibiotic to prevent anticipated

infection.

Indications for prophylaxis in surgery Wounds - Clean contaminated and contaminated wound- Clean wound in which implants or prosthesis are inserted- Animal or Human bite- Open fracture- Delay to cleaning > 6hrs- Foot/ Hand wounds - Wound length > 5cm- Crush- Wound involving body cavity/ perineum- Immuno-suppressed patient - Burns

General considerations Not a substitute or alternative to aseptic

practice and good surgical technique.Necessary only in high-risk cases of bacterial

contaminationPreop selection of antibiotic should consider

the normal flora in clean cases and the likely contaminant in dirty cases

Adoption of Policy on type antibiotics to use is infortant

Anatomical site Normal floraSkin Staphylococcus, streptococcus

propionibacteria Oral cavity Above, anaerobes & gram negative

rodsNasopharynx Staph., strept., H. influenzae and

anaerobesThorax Staph, strept, and propionibacteria

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 sterileLimbs Staph, strept, propionibacteria

Recommended drugs for some procedures

periop - It should start with premedication- Should be administer 30min- 1hr before the

surgery- Should be intravenous- Aiming at a saturated tissue concentration above

MIC at the time of surgery or manipulation.- Re-administer at 1-2 t½ of the antibiotics for

prolonged surgery- 24-48 hr is as effective as administration for 7days

therapeutic antibiotic useTherapeutic antibiotics is given to fight

infection that is already established.

1. Establish a Clinical Diagnosis and the need for Antibiotics base on history and physical examination

2 - Determine the Urgency of the situationNon-urgent situation: mild infection or

chronic infectionUrgent situation:- Suspected severe infection

3. Obtain an appropriate clinical specimens for examination, culture and sensitivity

4. Remove barrier to cure by - Debridement - sequstrectomy - I & D - Good wound care

5. Determine the most likely organism causing the infection

Focus of infection AgeEpidemiologic featuresPrior culture data

6. If multiple antibiotics are available to treat pathogen, choose the best agent

Prior antibiotic allergies Antibiotic penetrationPotential side effectsMedical condition of the patient

7- Antibiotic combination can be considered to achieve Synergism

8. Assess effectiveness of antibiotic therapy - Clinical assessment – ↓ temperature - 48 hrs 4BC antibiotics

3 - 4days 4BS drugs - Inflammatory markers – signif. ↓CRP < 25 %

from the baseline within 24 hrs. - Contagiousness of patient – BC 24 hrs. BS 5 days

9. Initial therapy may need modification after culture results are available

Modification not necessary if there is significant Relief of symptoms

Narrow spectrum of antibiotics should be used (to decrease the risk of colonization)

Negative cultures

Dangers of Indiscriminate Use - Widespread sensitization of populace- Changes of normal flora of body --> overgrowth of

resistant organisms - Masking serious infection without eradicating it (e.g.

abscess)- Direct Drug Toxicity- Development of drug resistance  - Alteration of individual and hospital bacterial ecology- Possibility of antagonism (ie. penicillin and tetracyclin) - Higher cost of treatment - False sense of security

Toxicity of commonly use AntibioticsDrugs Common occasional

Penicillin Allergic reaction/diarrhoa

Anaphylaxis

Cephalosporins Thrombophlebitis/ GI symp

Aminoglycosides Nephro/ototoxicity

Erythromycin GI irritation/ stomatitis

Clindamycin Diarrhoa/ rash

levofloxacin headache, dizziness or lightheadedness.

Nephrotoxicity, phototoxiciy

ConclusionSignificant current achievements in medicine

are attributed to good use of antibioticsSound knowledge and application of principle

of antibiotic use will prevent dangers associated with indiscriminate use of antibiotics

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References

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