Fundamentals of anaesthetics Flashcards
What do the pre-operative investigations that are done depend on
Patient co-morbidities & medication
Type of surgery : minor/intermediate/ complex (including haemorrhage risk)
Setting: elective OR emergency
Which score is used to as a common peri-operative risk system
ASA and POSSUM
Outline ASA
ASA 1: Healthy patient
ASA 2: Mild systemic disease. No functional limitation
ASA 3: Moderate systemic disease. Have functional limitation
ASA 4: Severe systemic disease that is a constant threat to life
ASA 5: Moribund patient. Unlikely to survive 24 hours, with or without treatment
What is POSSUM
Can be used to explain to patient if risk is high or not
-Mortality & morbidity risk
Pre-operative: risk discussion
Peri-operative: Need for Invasive monitoring?
Postoperative: Over 5% mortality risk should -> HDU/ITU post operative
How do you optimise and what is the perioperative control for: Diabetes
Optimise: Glycosylated Hb
Perio-operative control: When to use Insulin Sliding scales?
How do you optimise and what is the perioperative control for: HTN
Optimise: When to treat? (BP>160/80)
Perio-operative control: Maintain 20% of normal BP
How do you optimise and what is the perioperative control for: IDH
Optimise: Symptomatic (or major procedure) /ECG anomaly
Perio-operative control: BP & HR control. Consider post operative HDU
How do you optimise and what is the perioperative control for: asthma/COPD
Optimise: Symptomatic? Signs?
Perio-operative control: Medication according to BTS
How do you optimise and what is the perioperative control for: anticoagulants
Optimise: Why? Stop or not?
Peri-op: INR/APTR <1.5
Anti-platelets/LMWH resumption?
How do you optimise and what is the perioperative control for: sickle cell
Optimise: Haem review
Peri-op: Good care- warm, hydrated, analgesia, infection free
Who and what surgery is suitable for day surgery
Social: Patient consent, carer, home setup
Medical: Fitness, stable chronic, obesity not preclude
Surgical: Complication risks, controllable post op symptoms, mobile
When should you consider investigations for surgery: blood test anomalies
: anaemia, renal dysfunction
When should you consider investigations for surgery: lung function tests
Baseline ABG’s, FEV1<40% (predictor for postoperative ventilation)
When should you consider investigations for surgery: cardiac
ECG – ischaemia, arrhythmias, baseline
Echo – LV function & valves
Stress echo – low/int/high risk of ischaemia
Mallampati score, neck movement
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Why are patients starved before surgery
Reduce aspiration risk
What is the usual starve guidance
Food : 6 hours
Water: 2 hours
Which patients are at increased risk of aspiration during surgery
Bowel obstruction, reflux disease, trauma (causing slow gastric transit, opioids
What do you need to include to prescribe opioids
The dose The form The strength (where appropriate) The total quantity or dosage units of the preparation in both words and figures For instalment prescriptions, specify the instalment amount AND instalment interval
You must write how often to take in numbers and words
USE THE ANAESTHETIC SLIDE FOR PRESCRIPTION
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How is the oropharyngeal tube sized up
Compare the oropharyngeal tube from the corener of the mouth to the angle of the mandible
When is oropharyngeal tube used
To help to bag a patient
When do you use the bag-mask-valve
What oxygen can it deliver
When somebody is apnoiec only (not when a patient is trying to breathe because of the valve)
Can deliver up to 100% o2
What is a definitve airway
a tube placed in the trachea with cuff inflated below the vocal cords
Is an endotracheal tube a definitive airway
Yes it is
Is a supraglottic device a definiive airway
No
5 steps to safer surgery
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What does one need to consider for VTE
Mobility
Risk factors
Bleeding risk
How is dalteparin usually given
Sub cut
What is the MOA, SE and dose/route of the following antiemetics; Ondansetron
5HT3R-antagonist
Bradycardia
Long QT syndrome
4-8mg TDS
PO/IV
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What temperature do you want to keep people at
Keep temp>360 C
How do you maintain temperature dor someone with a procedule longer than 30 minutes?
What about longer procedure?
Procedure>30mins –> Bair hugger
Longer procedures –> consider fluid warming
How do you manage an acute asthmatic (severe bronchospasm outside of theatre)
A,B,C
O2 -Start high flow oxygen and gain IV access
Salbutamol nebulised 2.5-5mg
Hydrocortisone 100 mg IV 6 hourly or prednisolone orally 40–50 mg/day.
Ipatropium nebulised 0.5 mg (4–6 hrly) • IV salbutamol if not responding (250 mcg slow bolus then 5–20 mcg/min).
Theophylline/Aminophylline
Magnesium 2g IV over 20 minutes
When might adrenaline be used in severe bronchospasm
NB- In extremis (decreasing conscious level or exhaustion) adrenaline may be used: nebuliser 5 ml of 1 in 1,000;
Senior clinician only: IV 10 mcg (0.1 ml 1 : 10,000) increasing to 100 mcg (1 ml 1 : 10,000) depending on response.
Learn the table of drugs slide 38
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How do you treat a severe tension pneumothorax
You can put a large bore cannula in the 2nd ICS
Chest drain might take too long in this situation
Triggers for anaphylaxis
Stinhgs, nuts, food, Abx, anaesthetic drugs, contrast media
How might you recognise anaphylaxis
Airway problems:
Airway swelling, e.g., throat and tongue swelling (pharyngeal/laryngeal oedema). The patient has difficulty in breathing and swallowing and feels that the throat is closing up.
Hoarse voice.
Stridor – this is a high-pitched inspiratory noise caused by upper airway obstruction.
Breathing problems:
• Shortness of breath – increased respiratory rate.
• Wheeze
• Patient becoming tired.
• Confusion caused by hypoxia.
• Cyanosis (appears blue) – this is usually a late sign.
• Respiratory arrest.
Anaphyaxis treatment
Legs up, adrenaline, IV fluids, chlorphenamine and hydrocortisone???
When to transfuse generally
if fit and well, then when Hb <70
If they have acute conroanary syndrome, sepsis, neuro injusty, is when Hb is <90
What is the early warning scores
, based on simple scoring system in which a score is allocated to physiological measurements already undertaken when patients present to, or are being monitored in hospital
What are the paramteres used for NEWS score
1 respiratory rate 2 oxygen saturations 3 temperature 4 systolic blood pressure 5 pulse rate 6 level of consciousness.
What score is low medium and high
0 or 1-4 is low
5-8 (or individual parameter scoring 3)= medium
Aggregate 7 or more= high
What is sepsis
Infection + systemic inflammatory response syndrome
What is SIRS
Systemic inflammatory response syndrome
Two or more of Temp >38 or <36
heart rate>90bmp
Resp rate >20/min
White cell count
What to do if recognise sepsis within 3 hrs
1) Measure lactate level
2) Obtain blood cultures prior to administration of antibiotics
3) Administer broad spectrum antibiotics
4) Administer 30 ml/kg crystalloid for hypotension or lactate ≥4mmol/L “Time of presentation” is defined as the time of triage in the emergency department
What to do if recognise sepsis within 6hrs
5) Apply vasopressors (for hypotension that does not respond to initial fluid resuscitation) ; maintain a mean arterial pressure (MAP) ≥65 mm Hg
6) In the event of persistent hypotension after initial fluid administration (MAP < 65 mm Hg) or if initial lactate was ≥4 mmol/L, re-assess volume status and tissue perfusion.
7. Re-measure lactate if initial lactate elevated.
Indications for ABG
To obtain & interpret oxygenation levels
To assess for potential respiratory derangements
To assess for potential metabolic derangements
To monitor acid-base status
To assess carboxyhaemoglobin in CO poisoning
To assess lactate
To gain preliminary results for electrolytes and Haemoglobin
Can be conducted as a one off sample or repeated sampling to determine response to interventions
Contraindications for ABG
Local infection
Distorted anatomy
Presence of arterio-venous fistulas
Peripheral vascular disease of the limb to be sampled
Severe coagulopathy or recent thrombolysis
Sampling error for ABG
Presence of air in the sample
collection of venous rather than arterial blood
an improper quantity of heparin in the syringe, or improper mixing after blood is drawn
delay in specimen transportation
Complications related to ABG
Haematoma Nerve damage Arteriospasm or involuntary contraction of the artery Aneurysm of artery Fainting or a vasovagal response
