ICM - Equipment OSCE

Question 1

Arterial line pressure transducer

Answer 1

• Transducer - transforms energy from one form to another- Catheter in direct continuation with column of fluid under pressure in rigid/stiff tubing- Sensitive diaphragm attached to strain gauge - Wheatstone bridge set of resistors- Fourier analysis to construct wave form Dampening - reduces amplitude of oscillations - bubbles, kinks, long compliant tubingOptimal dampening = 0.7

Question 2

LP

Answer 2

MC&SViral PCRBiochem - protein, glucose, LDHXanth/bilirubinCytology

Question 3

PAC

Answer 3

2 lumens for fluids/drugs1 lumen for balloonMixed venous sats monitor - SvO2Thermistor and thermal filamentCm markings

CO by thermal dilution

Question 4

Three compartment chest drain set

Answer 4

Issue with single chest bottle is that as more fluid fills a single chamber more positive pressure is required to expel further fluid or air.Two chamber system has a drainage collection bottle first, an underwater seal in the second bottle with a constant 2cm below the water line seal.Three chamber design adds a suction pressure regulator in the third bottle which regulates the suction using an underwater tube open to the air. Main disadvantage is that if the suction tube blocks then pressure will rise in the chambers and cause the pneumothorax to re-expand.

Question 5

Sengstaken-Blakemore tube

Answer 5

Gastric and oesophageal balloonCan not be used with known oesophageal stricture or recent surgeryHow to use:Most patients I&VLocal anaesthetic and lubricateInsert via nose or mouth to at least 50cmConfirm with CXRInflate gastric balloon with 50ml aliquots up to 250-300mlsPull ballon up to fundus and tape in place

Complications:PainHaemorrhageOesophagael rupture Pressure necrosis - limit time inflated, only use for 24 hrs