Sterilization

By:Dr. Yasser El Basatiny

Prof. of Laparoscopic Surgery

Antisepsis

• Definitions:Antisepsis = against putrefactionTo eliminate or reduce the germs • Antisepsis: use of antimicrobial chemicals on

human tissue• Disinfection: use of antimicrobial chemicals on

inanimate objects

Historical background

• In 18th and 19th century , serious infections among hospitalized patients, morbidity and mortality was very high nearly all trauma and surgical wound got infected and suppuration

• Hand wash and clothing change policy reduced maternal mortality from 11.4% in 1846 to 1.3% in 1848

• Pasteur’s discovered bacterium and it’s role in wound infection.

• Lister published 1st antiseptic principle in 1867• Kocher reported 2.3% infection rate in clean wound by

1899.

Aseptic technique

• Hygienic hand wash• Preoperative preparation of patient’s skin• Gloving• Sterile draping• Isolation precaution• Autoclaving of instruments• Proper waste disposal

Principles of sterilization Operating room:• Minimum size is 5x5 meter• Appropriate ventilation, changing room air 20 to 25

times per hour.• Passing inflow air through “high efficiency particulate

air” HEPA filter• All doors of OR. should be closed• Air pressure should be positive

The primary source of perioperative infection is the patient and the secondary source are the OR team

A CFD simulation of a Cleansuite installation in an operating room shows laminar air flowing from diffusers in the ceiling, down and away from the patient, and out vents near the floor

Patient as a source of infection

Wounds: • Clean wounds• Clean contaminated• Contaminated• Dirty

Intrinsic resistance to contamination• Age, obesity, diabetes, cirrhosis, uremia and

immunodeficiency.

Methods of sterilization

• Iodophors (Betadine) broad spectrum antimicrobial against fungi, viruses, gram positive and gram negative.

Operative team

• Scrub the hands and arms with antiseptic solution like iodophors and chlorhexidine

• Face mask over the mouth and nose, head cover and shoe covers

• Disposable sterile gloves• Sterile gown: impermeability to moisture.• Sterile drapes impermeable to bacteria

Methods of sterilization

• Steam heat (Autoclave)• Chemical solution: used for instruments

tolerate moisture but not heat. 2% glutaraldehyde

• Dry heat: for items can tolerate heat and not penetrated well by steam

• Gas sterilization: for delicate instruments

Autoclave sterilizer

Surgical technique Gentle handling of tissues, careful hemostasis

and appropriate irrigation.• Incisions: along normal skin line, adequate

exposure, same incision in reoperation• Atraumatic handling: minimize necrosis of skin

margin• Dissection: least amount of trauma in

dissecting in natural tissue planes• Debridement: the most important single factor

in management of contaminated wounds

Surgical technique

• Hemostasis: to minimize blood loss and prevent hematoma formation

• Wound closure: primary closure for clean wounds, delayed primary closure should be considered on or after 4th day in contaminated wound

• Suturing: simple interrupted sutures, mattress suture, subcuticular suture

Surgical technique • Dressing: protect the wound from mechanical trauma

and bacterial invasion, sterile dressing applied before removal of drapes, moist dressing speed up epithelization 10 folds, infected wounds needs dressing that absorb exudates.

• Immobilization: it reduce lymphatic flow and minimizing the spread of wound flora, more resistance to bacterial growth, elevation reduces interstitial edema.

• Suture removal: proper timing for suture removal• Prophylactic antibiotics: before skin incision

Operative equipments

Electrocautery: • High frequency alternating

current• For hemostasis and incise

tissue • Unipolar, rapid dehydration

of the cell and the blood vessels within the tissue coagulate

• Bipolar, more precise and confines the damage to the tissue between the tips of forceps

Operative equipments Argon beam coagulator (ABC):• For parenchymatous organs, unipolar coagulation non touch

technique. Less depth of penetration 2-3 mmSurgical lasers:• Argon Laser, ophtalmogic tratment and vascular anastomosis.• CO2 Laser, to cut tissue• Nd:YAG Laser, flexible quartz fiber can be used for paranasal

sinus and tracheobronchial tree• Er:YAG Laser, very strongly absorbed by the water of tissue

can vaporize cartilage, fibrous tissue and boneHarmonic scalpel• Use of ultrasonic power for cutting and coagulation

Sutures and needles

Needles• Open French eye needle• Swaged on needle (eye less)• Straight or curved• Cross section: can be round triangular or

flattened• Needle point: cutting, tapered or blunt

Sutures and needlesAbsorbable sutures• Absorption and disappearance of the suture from the tissue

implantation site• Catgut: made from the intestine of cattle or sheep, absorption of

plain catgut is about 10 days. Chromic catgut (treated by chromium salt) its absorption is delayed up to 20 days.

• Polyglycolic acid (Dexon): absorbable braided, synthetic suture, higher tensile strenght, reabsorption by hydrolysis at 60 to 90 days.

• Polyglyconate ( Maxon): synththetic monofilament.• Polyglactic acid (Vicryl): braided synthetic suture, very high

tensile stenght, absorbed in 60 days• Polydioxanone (PDS): monofilament absorbable

Sutures and needles

Non absorbable sutures• Silk: protein filament from the silkworm larva, dyed,

treated by polybutilate and braided. Good tensile strength

• polyester (Dacron): superior strength and durability• Nylon: synthetic polyamide polymer, monofilament and

multifilament.• Polyprolene (Prolene): monofilament, minimal tissue

reaction• Stainless Steel: low carbon iron alloy, monofilament or

multifilament. Used for bone suturing

Sutures and needles

Staplers• TA Instruments: linear everting double line,

length 30, 55, 90 mm. staple size 3.5 and 4.8 mm. 3.2 mm for vessel closure.

• GIA Instruments: two double rows of staples and divide the tissues in between.

• EEA Instruments: end to end or end to side circular staplers

• Skin staples: speed of skin closure and efficacy.

DrainsHistorical aspects• Dates back to Hippocrates• Metal tubes, glass tubes, bone, gauze and

combination of gauze and rubber• Tapered lead and bronze tubes to drain

abdominal cavity by Celsus in 1st century• Penrose drain 1890, cigarette drain 1897• Air vent suction by Heaton 1889

Principles of wound drainage

• To drain cavity or soft tissue to prevent collection of serum or blood

• It is not a substitute for hemostasis or meticulous technique

• Either passive or active, prophylactic or therapeutic.

• It should be soft, nonirritating, firm, smooth and resistant to decomposition.

Types of drains

Penrose drain (obsolete) • Efficient but there is significant risk of secondary

infection.• Soft, flexible latex rubber wick• To drain purulent material, blood or serum from

body cavity• Brought out through a separate stab at dependant

area• Anchored to the skin with a non absorbable suture

Types of drains

Closed suction drain• Lower infection rate, might clog and cease

function• Firm multi-holed catheters made of polyvinyl

chloride or silicone.• Effective to drain soft tissue under large skin

flaps

Types of drains

Sump drain• Large and bulky• Double or triple lumen allow irrigation and

aspiration• Rely on continuous flow of air from outside

predisposes to secondary infection.• Less likely tissue occlusion• For high volume enteric fistula

Types of drains

Closed suction Penrose drain• Combination of closed suction drain and Penrose

drain which uses capillary action• Low secondary infection, effective in abdominal

cavity• Ideal drainage systemPercutaneous catheters• Inserted by radiologists CT or US guided to drain

accessible localized collection

Minimal invasive surgery

• Laparoscopic surgery• Thoracoscopic surgery• NOTS “natural orifice transluminal surgery• Single port laparoscopic surgery

Minimal invasive surgery

• To reduce tissue injury, fast post operative recovery, short hospital stay

• Pneumo-peritonium to create room to work

Thank you