Pre-op Flashcards
Describe the ASA classification to stratify the pre operative physical status (7 )
I: healthy patient
II: mild systemic disease eg obesity, treated ht, controlled dm 2, smoker (no functional limitation )
III: severe systemic disease, not incapacitating eg mild cardiac failure, distant prev mi (some), diabetes, poorly controlled HT
IV: severe systemic disease, constant threat to life eg exsanguinated with ruptured ectopic pregnancy, severe renal failure, recent MI, EF <25% (functionally incapacitated)
V: moribund, not expected to survive 24h irrespective of operation eg ruptured aneurysm
VI: brain dead presenting for organ donation
E: Emergency
Describe and interpret the METS (metabolic equivalents) scores (4)
1: can read, watch TV, eat, get dressed, walk 100m on level ground- poor candidate for anaesthesia
2-3: can walk on level ground 3-4 km/h , light housework
4-10: can climb few stairs, walk on level ground 6 km/h, run short distances, heavy household chores, moderately strenuous sports eg golf, dancing. - Can handle anaesthesia
>10: highly strenuous sports eg soccer - excellent candidates
Name 4 risk factors post op pulmonary complications
•age > 60
• severe COPD
• reduced exercise tolerance
• Heart failure
• surgery > 3h
What must hba1c be before elective surgery?
<9
Describe the NPO guidelines pre-op
2,4,6,8 rule
8 hours before surgery: no meat or fried, fatty food.
6 hours: no milk or solid food
4 hours: no breast mik
2 hours(new guide line 1h for Paeds ): NPO, no clear fluids
Which medications should be discontinued pre-op in hypertensive patients?
• ace-i and arb morning of surgery (10 hours pre-op) to prevent acute hypotension
• continue beta blocker and diuretics
Which medications should be discontinued pre-op in diabetic patients?
Stop oral hypoglycaemic (metformin because risk intra-op lactic acidosis, sulfonylureas because risk hypoglycaemia) 1-2 days before surgery and convert to insulin sliding scale if necessary
Which premedication can be given to anxious adults?
Midazolam
Which pre-op special investigations should be performed in asymptomatic patients in which major blood loss is expected? (5)
• FBC
• clotting
• UCE
• ECG
• Blood typing
Which pre-op special investigations should be performed in asymptomatic neonates? (2)
• FBC
• UCE
Which pre-op special investigations should be performed in asymptomatic males aged 40-49? (1)
ECG
Which pre-op special investigations should be performed in asymptomatic patients aged 50-64? (1)
ECG
Which pre-op special investigations should be performed in asymptomatic patients aged 65 or more? (5)
•Fbc
• UCE
• blood glucose
• ECG
.Cxr
Which pre-op special investigations should be performed in asymptomatic cardiovascular disease? (4)
• FBC
• UCE
• ECG
• CXR
Which pre-op special investigations should be performed in asymptomatic lung disease? (3)
FBC
CXR
ECG
Which pre-op special investigations should be performed in asymptomatic bronchial hyperreactivity? (1)
Lung functions - must be able to hold breath at least 15 seconds (sabrazes test - measure FRC)
Which pre-op special investigations should be performed in asymptomatic smoking 20 pack years or more? (2)
ECG
CXR
Which pre-op special investigations should be performed in lung resection? (6)
FBC
UCE
BGA
ECG
CXR
lung function test
Which pre-op special investigations should be performed in asymptomatic kidney disease or diuretic use? (4)
FBC
UCE
ECG
CXR
Which pre-op special investigations should be performed in asymptomatic hepatobiliary disease? (5)
FBC
UCE
clotting (APTT, PT, INR)
blood glucose
LFT
Which pre-op special investigations should be performed in asymptomatic DM? (5)
FBC
UCE
blood glucose
ECG (silent MI)
CXR
Which pre-op special investigations should be performed in asymptomatic CNS disease? (2)
FBC
UCE
Which pre-op special investigations should be performed in malignancy/oncotherapy? (5)
FBC
UCE
LFT
ECG
CXR
Which pre-op special investigations should be performed in asymptomatic abnormal clotting? (2)
FBC
clotting (APTT, PT, INR)
Which pre-op special investigations should be performed in CV medication use? (2)
ECG
UCE
Which pre-op special investigations should be performed in corticosteroid use? (2)
UCE
blood glucose
Which pre-op special investigations should be performed in anticoagulant use? (2)
FBC
clotting (APTT, PT, INR)
Which pre-op special investigations should be performed in planned induced hypotension? (3)
FBC
UCE
LFT
Which pre-op special investigations should be performed in patients that need post op intensive care? (1)
BGA
Name 3 Resp conditions that justify cancellation elective surgery
Bronchospasm
Upper airway infection within last 2 weeks
Productive cough or pneumonia previous 6 weeks
Minimum haematocrit in anaemia and polycythaemia to proceed with elective surgery?
> 25%
Minimum haematocrit in healthy patients to proceed with elective surgery?
> 21%
Minimum haematocrit in paediatric patients to proceed with elective surgery?
Younger than 3 months: >30% (high O2 consumption)
Older babies: >27%
Minimum haematocrit in patients with hypoxic hypoxia to proceed with elective surgery?
30%
4 steps of the pre-op evaluation?
- Optimise: chronic disease/rx stop/add, clinical findings eg wheeze, special investigs eg Hb
- Risk stratify: (ASA I-IV), MET’S
- Anaesthetic plan: premed, GA, regional, airway, monitoring, post op care
- Informed consent
Name 5 contraindications pre-op sedatives
- if it will aggravate hypoxia eg lung disease, cyanosis heart disease
- any airway pathology: decreased muscle tone can cause obstruction
- increased sensitivity to sedatives: sleep apnea
- decreased level of conciousness
- babies younger than 1 or below 10kg (unless constant observation)
Name 3 classes of sedatives with examples that can be used pre-op
- benzodiazepines: midazolam, temazepam, oxazepam
- opioids: morphine, tilidine. Especially good for pre-op pain
- antihistamines: promethazine, trimeprazine (antisialogogue and antiemetic, but no longer widely used due to extrapyramidal effects, prolonged sedation, hypotension)
What is kefzol?
Cephazolin: first generation cephalosporin
What does kefzol cover?
Broad spectrum, mainly skin flora
Gram positive staph and strep
Some gram negative: e coli, moraxhella catarrhalis, klebsiella pneumonia, proteus mirabilis
