Preparation for surgery Flashcards
What is the definition and examples of ASA Grade I?
- Normal healthy patient
- Healthy, non-smoking, no or minimal alcohol use
What is the definition and examples of ASA Grade II?
- A patient with mild systemic disease
- Mild diseases without substantive functional limitations, e.g. smoker, social alcohol drinker, pregnancy, obesity (BMI 30-40), well-controlled diabetes mellitus/ HTN, mild lung disease
What is the definition and examples of ASA Grade III?
- Patient with severe systemic disease
- Substantive functional limitations; one or more moderate to severe diseases e.g. poorly controlled DM/HTN, COPD, BMI>40, active hepatitis, alcohol dependence or abuse, implanted pacemaker, moderate reduction of ejection fraction, end-stage renal disease undergoing regular dialysis, >3 months of MI history, CVAs
What is the definition and examples of ASA Grade IV?
- A patient with severe systemic disease that is a constant threat to life
- e.g. recent (<3 mth) MI, CVAs, ongoing cardiac ischaemia or severe valve dysfunction, severe reduction of ejection fraction, sepsis, DIC, ARD or ESRD not undergoing regularly scheduled dialysis
What is the definition and examples of ASA Grade V?
- A moribund patient who is not expected to survive without the operation
- e.g. ruptured abdominal/ thoracic aneurysm, massive trauma, intra-cranial bleed with mass effect, ischaemic bowel in face of significant cardiac pathology or multiple organ/ system dysfunction
What is the definition and examples of ASA Grade VI?
- A declared brain-dead patient whose organs are being removed for donor purposes
What are 5 available routes for establishing intravenous accessing during/before surgery?
- Peripheral venous cannula
- Central lines
- Intraosseous access
- Tunneled lines
- Peripherally inserted central cannula
What are 3 advantages of peripheral venous cannulae?
- easy to insert
- minimal morbidity
- when properly managed, infections may be promptly identified and cannula easily re-sited
What is the benefit of wide-lumen cannulae?
Can provide rapid fluid infusions
What are 2 problems with peripheral venous cannulae?
- Problems relating to peripheral sites
- Unsuitable for administering vaso-active drugs such as inotropes, and irritant drugs such as TPN
What are 3 key disadvantages of central lines?
- Insertion more difficult that peripheral venous cannulae
- Coagulopathies may lead to haemorrhage following iatrogenic arterial injury
- The multiple lumens are relatively narrow and don’t allow rapid rate of infusion
What is normally done to aid the insertion of central lines?
most operators and NICE advocate use of ultra-sound
What are 2 sites for central lines?
- Internal jugular
- Femoral lines
What are 2 advantages and 1 disadvantage of femoral lines over internal jugular lines?
Pros: easier to insert, iatrogenic injuries easier to manage
Cons: Prone to high infection rates
What is the preferred route for a central line?
Internal juugular route
What is a key advantage of central lines?
They have multiple lumens allowing for administration of multiple infusions
Where is intraosseous access usually performed?
At the anteromedial aspect of the proximal tibia
What does intraosseous access provide access to?
The marrow cavity and circulatory system
Traditionally which patients is intraosseous access performed in, and who else can it be used for?
Traditionally paediatrics; can also be used in adults and wide range of fluids infused
What are 2 examples of tunneled lines for intravenous access?
- Hickman
- Groshong
Among which patients are tunnelled lines popular?
Patients with long term therapeutic requirements
How and where are tunnelled lines usually inserted?
Using ultrasound guidance, into internal jugular vein then tunnelled under the skin. Cuff of woven material sited near end, anchors device into tissues
How can tunnelled line devices be removed?
Cuffs at the end require formal dissection to allow device to be removed
What can tunneled lines for intravenous access be linked to?
Injection ports located under the skin
In which paient population are tunnelled lines particularly popular?
Paediatrics
What is a peripherally inserted central cannula (aka PICC line) popularly used for?
Establishing central venous access
What is the advantage of a PICC line to obtain central venous access?
They are inserted peripherally so less prone to major complications relating to device insertion than conventional central lines
What are the 5 cannula colours and sizes, and the maximal flow rates of each?
- Orange 14g - 270ml/min
- Grey 16g - 180ml/min
- Green 18g - 80ml/min
- Pink 20g - 54ml/min
- Blue 22g - 33ml/min
What are 6 types of nutrition options in surgical patients?
- Oral intake
- Nasogastric feeding
- Naso-jejunal feeding
- Feeding jejunostomy
- Percutaneous endoscopic gastrostomy (PEG)
- Total parenteral nutrition
How can oral intake for surgical patients be supplemented?
Calorie-rich dietary supplements
How is naso-gastric feeding usually administered?
Via fine bore naso-gastric feeding tube
What are 2 key things that complications of nasogastric tubes relate to?
- Aspiration of feed
- Misplaced tube
In what group of patients may naso-gastric feeding be safe to use?
Patients with impaired swallow
When is naso-gastric feeding often contra-indicated and why?
Following head injury due to risks associated with tube insertion
What are 2 key advantages of naso-jejunal feeding?
- Avoids problems of feed pooling in stomach (and risk of aspiration)
- Safe to use following oesophagogastric surgery
What is the safest way to insert a naso-jejunal feeding tube and why?
Easiest if done intra-operatively, as more technically complicated than NG tube
What is a feeding jejunostomy?
Surgically sited feeding tube - from skin to jejunum
What are 2 key advantages of feeding jejunostomies?
- May be used for long-term feeding
- Low risk of aspiration and thus safe for long term feeding following upper GI feeding
What are 2 risks of feeding jejunostomies?
- Tube displacement
- Peritubal leakage immediately following insertion, which carries a risk of peritonitis
How are percutaneous endoscopic gastrostomies (PEGs) inserted?
Combined endoscopic and percutaneous tube insertion
In which patients may it not be possible ot insert a PEG?
Those who cannot undergo successful endoscopy
What are 2 risks of PEGs for feeding?
- Aspiration
- Leakage at the insertion site