Soft Tissue Surgery: Haemostasis and Asepsis Flashcards
What are the different basic haemostatic techniques?
Pressure- arrest low-pressure haemorrhage from small vessels by applying pressure with a swab
Haemostatic forceps- use the smallest suitable straight or curved haemostats to crush the vessel- physically occlude
Tip clamping- apply the tip of smaller haemostats with transverse jaw serrations ay 90d
Jaw clamping- larger haemostats with longitudinal jaw serrations at 90d to larger vessels or tissue pedicles
What are radiofrequency instruments?
What are the different types of cautery?
Radiofrequency instruments- damped radiofrequency, alternating current to coagulate tissue and cause vessel thrombosis. Use the lowest current intensity and duration
Monopolar cautery- current from a single hand electrode to a ground plate under patient- resistive heating can cut and cauterise
Bipolar cautery- current flows between the two sides of a hand-held forceps- more precise, required less current and better in wet
What are examples of vessel sealing devices?
Electrothermal bipolar vessel sealers-
use a radiofrequency current and pressure to denature and seal collagen and elastin in the vessel walls and surrounding tissues and ‘weld’ them together
Harmonic scalpels-
Use ultrasonic vibrations of the instrument tip to cause heating and coagulation of the tissue. Can also cut tissues if the appropriate setting is selected
What are the different ligatures?
Simple circumferential ligatures-
apply a ligature a few mm from the cut and of the vessel to avoid slippage, using a square knot and three flows
Transfixing-
penetrated and encloses the vessel/pedicle
Halstead transfixing ligature has single know in the larger suture loop, while the modified transfixing ligature has a know in the loop also
What are vascular clips?
What needs to bedone to ensure the clips permanently occlude the vessel?
Metal or absorbable polymer vascular clips mounted on single or multiple sure applicators are rapid, convenient but more expensive
Ensure clips permanently occlude the vessel:
Remove as much surrounding tissue as possible before application
The vessel diameter should be greater then 1/3 and less than 2/3 length
Apply the clip several mm from the end of the vessel
Clip arteries and veins separately
Use multiple clips on arteries and larger veins
What are topical haemostatic agents?
Granules, powder or sheets of collagen, fibrin or more exotic materials like shellfish chitin
Acts as a scaffold for fibrin clot formation
Mainly used for control of persistent capillary haemorrhage
How are wounds classified based on their likely degree of contamination?
Clean- elective surgical wounds not entering the respiratory, urogenital or GI tract with no break in asepsis and primary closure
Clean- contaminated- surgical wounds involving the resp, urogen or GI, without significant contamination or minor break-in asepsis
Contaminated- fresh traumatic wounds less than 4-6 hours old, surgical wounds involving resp, uro, GI with significant contamination, surgery in the presence of inflammation, major break in asepsis
Dirty- traumatic wounds greater than 4-6 weeks old, contaminated with foreign material/devitalised tissue, perforation of hollow viscus, surgery in presence of abscessation
Why can propofol potentially break asepsis?
Why are endocrinopathy patients at higher risk?
What sex of the patient is at higher risk?
How can tissue response to infection be compromised?
Propofol- suspended lipid-based emulsion that can support bacterial growth, if contaminated and injected can cause wound infection
Endocrinopathies- patients with diabetes mellitus, hyperadrenocorticism and hypothyroidism may be at increased infection risk due to immunosuppression
Sex- males are at increased risk due to the immunomodulatory effects of androgens
Tissue response compromised due to:
trauma, foreign material, ischaemia (shock/trauma), poor nutrition, chemotherapy, systemic disease
What are the two sources of bacterial contamination?
Endogenous- originating from skin, resp and GI tract
maybe direct or via blood/lymph
Exogenous- bacterial contamination from the room air, surgical team, instruments and drapes- good aseptic technique
How can surgical infections be prevented?
Patient selection and preparation-
postpone if preexisting disease, clip the surgical site, thoroughly clean the surgical site, use surgical drapes
Preparation of the surgical team-
the surgeon and assistants pre-op hand rub, wear sterile gloves, scrub suits, head coverings, masks
Sterilisation of equipment-
familiarise yourself with the operation of the autoclave
Preparation of operating theatre- disinfect, don’t prepare, low numbers of people
Wound lavage- copious amounts at end
Post-op care- monitor signs of infection
Antibacterials
When should prophylactic antibacterials be used?
Clean surgery- only if the surgery will last more than 90 minutes
Clean-contaminated or contaminated surgeries
Dirty surgeries- wounds are already infected so give course
What are the definitions for the following terms:
Asepsis
Disinfection
Nosocomial infections
Prophylactic antibacterials
Sterilisation
Asepsis- use of germicidal substances on living tissue
Disinfection- germicides on inanimate objects
Nosocomial infections- hospital-acquired infections, often caused by resistance
Prophylactic antibacterials- before bacterial contamination has occurred
Sterilisation- the process of destroying all microorganisms
