Laparoscopy Flashcards
components lap stack
monitor gas insufflator computer light source digital camera control printer
why co2 for insufflation
non combustible
physiological
components of rigid endoscope
optical system - distal tip objective lens, relay system and a diopter lens which magnified and brings coherent image to eye piece
mechanical sheath, protection, allows sterilsation
non coherent glass fibre system to transmit light
instrument flow channel
light transmission
Light is guided to the tip of the endoscope via a noncoherent fi bre bundle
which starts in the upward projecting “light” pillar. This is attached, via a noncoherent
fi bre-optic light guide, to the external light source.
distal tip objective lens
The distal tip objective lens can be angled off the 0° to give an oblique view – the
most commonly used angles in urology are 12°, 30°, and 70°. By rotating these
scopes on their axis, a differential fi eld of view can be achieved with minimum
physical trauma to the structure being examined.
light source
Generated light typically comes from a halogen bulb, which gives a softer light, or
a xenon bulb, which gives a brighter white light
effects pneumo -5
vagal stimulation decreased venous return decreased renal function gas embolus increased airway pressure
correc site surgery -5
follow NHS NPSA guidelines
meet patient preop mark with indelible ink
ward staff review documentation and confirm marker
prior to anaesthesia review notes and mark
prior to surgery WHO checklist and review mark
ideal insufllation gas 6
physiologically inert highly soluble in blood colourless chemically stable widely available inexpensive
air as insufllant
risk combustion and air embolus
advantage no acidosis or hypercapnia
nitrogen oxide
no acidosis
high solubility
risk combustion
helium
inert non combustible
dissolve slowly risk embolism
expensive
disadvantage co2
hypercapnia
peritoneal irriation
complications co2 insufflation 5
vagal stimulation decreased venous return renal function gas embolus increased airway pressure
complications co2 insufflation 5
vagal stimulation decreased venous return renal function gas embolus increased airway pressure
metbolic consequenes of co2 4
hypercarbia
acidosis
these cause vasodilatation and decreased CO
stimulate SNS resulting in tachycardia and VC
air embolus and co2 risk vs air
risk low due to rapid absorption in blood and ability of blood to transport high levels
five times volume of co2 needed at 200mls vs air to have embolic effect
diagnosing air embolus
arrythemia
myocardial ichaemia
increased central venous pressure
pulmonary hypertension
managing air embolus
inform surgeon stop insufflation venitalte 100% oxygen left lateral decubitus position adequate hydration central venous catheter aspirate co2 resusicitate fluids vasopressors inotropes drugs dilate pulmonary circulation hyperbaric oxygen
why oxygen in co2 embolism
The patient should be ventilated with 100% oxygen in order to wash out carbon dioxide and improve ventilation perfusion mismatch and hypoxemia.
why left lateral decubitus position in air embolism
The patient should be placed in a steep-head down, left-lateral decubitus (Durant’s) position in order to allow gas bubbles to rise to the apex of the RA and to prevent entry into the pulmonary artery
advantages rod lens system
durability superior light passage and image quality reduced diameter of instrument colour reproduction
how does optic fibre work
via total internal reflection
optic fibres grouped in parallel fashion and arrnaged in external plastic sleeve
in digital system used CMOS chip with photons striking charge coupled device
