Monitoring of the Surgical Patient Flashcards
Why do we do hemodynamic monitoring on a surgical pt?
- provides info as to the CP status of pt
- traditional clinical assessments are usually unreliable
- major changes in CV status may not be clinically obvious
- invasive techniquies must be utilized
Indications for arterial catheterization? (ART line)
A. need for continuous BP monitoring
- shock states
- hypertensive crisis
- surgery in high risk pts
- use of potent vasoactiv or inotropic drugs
- controlled hypotensive anesthesia
- situations that may lead to rapid changes in cardiac fxn
B. need for frequent arterial blood sampling
CI of Art lines?
No absolute CI relative CI: - bleeding problems (hemophilia) - anticoag therapy - presence of vascular prosthesis - local infection
Sites for art lines?
- radial artery
- axillary artery
- femoral artery
- dorsalis pedis
- superficial femoral
- brachial
Why is radial artery firstline choice for art lines?
- dual blood supply
- MC used site
- simple canulation
- low complication rate
- can perform modified allen’s test to assess ulnar artery, also doppler, plethysmography, pulse oximetry
Use of axillary artery for art line?
- for long term monitoring
- large size
- close proximity to aorta
- deep location
- technical difficulty in insertion
- located near neurovascular structures
Pros and cons for using femoral artery as art line?
- large size and superficial location
- but prone to atherosclerosis
- difficult to keep clean
Why is the superficial temporal artery not used often for art lines?
- surgical exposure is reqd (cut down)
- neuro complications observed
Use of brachial artery for art line?
- only for short term use
- risk of median nerve contracture (volkman’s contracture)
Complications of art catheterization?
- failure to cannulate
- hematoma
- disconnection from monitoring system
- infection: catheters placed for more than4 days, surgical insertion, local inflammation
- retrograde cerebral embolization
- A-V fistula/pseudoaneurysm
- severe pain, distal necrosis
What is central venous pressure monitoring? How is this done?
- this is a direct measurement of BP in the right atrium and vena cava
- it is acquired by threading a central venous catheter (subclavian double lumen central line) into any of the several large veins)
- threaded so that the tip of the catheter rests in lower 1/3 of SVC, pressure monitoring assembly is attached to distal port of multilumen central vein catheter
Why use CVP for monitoring?
- in seriously ill pts the vital problem is determination of proper amt of fluids and blood requirements necessary to maintain an optimal blood volume in the:
preop
operative
postop - it is a reliable procedure to eval properly and promptly optimal fluid and blood requirement for these pts
- the procedure removes much of the guess work in rapid restoration and maintenance of adequate circulation w/o fear of overloading the heart
Sites of CVP monitoring caths?
- subclavian vein:
easiest to cannulate, pneumothorax MC complication, difficult to control bleeding - internal jugular vein: lower risk of pneumothorax, arterial puncture MC complication
- external jugular vein
- basilic vein
CVP is determined by what?
- it is measured anywhere in SVC or IVC or immediate tributaries
- it is determined by complex interaction of:
blood volume
cardiac pump action
vascular tone - serves as an index of circulating blood volume relative to cardiac pump action
- it will reflect ability of cardiac pump action to handle returning blood at particular time
Indications for CVP?
- when massive blood replacement is instituted rapidly in rapid exsanguinating type of bleeding
- in acute blood vol deficit in cases operated for strangulating type of intestinal obstruction where rapid fluid replacement is indicated
- in obscure cases of shock immediately post-op whether hypovolemic due to internal bleeding or nonhypovolemic from MI
- in elderly pts w/ limited cardiac reserve undergoing difficult, time consuming operations
- in surgical pts w/ anuria due to possible renal shutdown