Anaesthesiology: Recognising The Critically Ill Patient

Question 1

Top 5 early and late signs of physiological deterioration

Answer 1

Early signs:

1. Partial airway obstruction
2. Poor peripheral circulation
3. pH <7.3 but >7.2
4. Base deficit -5 to -8
5. Drain fluid loss > expected

Late signs:

1. Unresponsive to voice
2. pH <7.2
3. Base deficit

Question 2

MEWS score (Modified Early Warning Score)

Answer 2

1. SBP
2. HR
3. RR
4. Temp
5. AVPU (Alert, Verbal, Pain, Unresponsive)

Question 3

Airway obstruction

Answer 3

Complete airway obstruction

• silent but exaggerated respiratory effort
• “See-saw” breathing in complete / near complete obstruction

Partial airway obstruction

• commonly a result of reduced consciousness
• noisy breathing / stridor (large airway obstruction)

Assessment:
Ask patient name + place

Clear, coherent answer imply:

• Patent airway
• Sufficient respiratory capacity to permit speech
• Adequate cerebral perfusion for cognitive processing

Management:

1. Call senior for help
2. Do not lay flat as may precipitate complete obstruction (patient will adopt best position i.e. sitting upright + lean forward)
3. Ensure no cervical spine injury
4. Manual in-line stabilisation if indicated
5. Oxygen
   - titrated to achieve SpO2 94-98% (avoid hyperoxaemia)
6. Airway maneuvers
   - Head tilt, Chin lift, Jaw thrust
7. Airway adjunct
   - Oropharyngeal / Nasopharyngeal airway

Question 4

Breathing

Answer 4

Adequate breathing requires:

1. Intact central respiratory drive
2. Respiratory muscle activity
3. Sufficient surface area for alveolar gas exchange
4. Adequate pulmonary circulation

Assessment

1. Tachypnea
2. Inability to complete sentences
3. Accessory muscles
   - inspiratory contraction of SCM + Scalene
4. Cyanosis
5. Paradoxical breathing
   - chest trauma
   - diaphragmatic dysfunction (e.g. neurological problem, fatigue)
   - upper airway blockage (e.g. sleep apnea)
   - severe electrolyte imbalances (e.g. severe malnutrition, vomiting, diarrhoea)

Question 5

Circulation

Answer 5

Shock:

• Oxygen supply to organs / tissues is ***inadequate to meet metabolic demand
• Pump failure vs Peripheral circulatory failure

Pump failure:
- Cardiogenic shock

Peripheral circulatory failure:

• Hypovolaemic shock (Absolute hypovolaemia)
• -> Haemorrhage
• -> Burns
• -> Excess GI loss
• Distributive shock (Relative hypovolaemia: Vasodilatation)
• Sepsis
• Anaphylaxis
• Neurogenic shock

CAN be mixed in complex situation e.g. Septic cardiomyopathy (vasodilatation + pump failure)

Normal BP =/= No shock
- e.g. Hypertensive patients

Low BP =/= Shock
- e.g. Young fit females

Hypotension often late + worrying sign

Signs of shock often masked in certain patient groups:

• Young fit adults
• Pregnant women
• Patients on beta-blockers

Signs of end organ hypoperfusion:

1. Delayed capillary refill
2. Tachypnea
3. Confusion, Agitation
4. Oliguria (check by foley)
   (5. Hyperlactaemia)

Question 6

Disability

Answer 6

1. GCS scale
2. AVPU scale

Factors affecting consciousness:

1. Hypoxia, Hypercarbia
2. Hypothermia
3. Hypoglycaemia
4. Electrolyte imbalance
5. Sepsis
6. Metabolic derangement
7. Alcohol, drugs, toxins
8. Primary neurological conditions (e.g. intracranial haemorrhage, ischaemia, infection)

Question 7

Exposure

Answer 7

Expose patient to examine throughly

Question 8

SOFA score (Sequential Organ Failure Assessment)

Answer 8

1. Respiration (PaO2)
2. Coagulation (Plt)
3. Liver (Bilirubin)
4. Cardiovascular (MAP)
5. CNS (GCS)
6. Renal (Creatinine, urine output)

qSOFA (each score 1, max score 3):

1. ***Low BP (SBP <=100)
2. ***High RR (>=22)
3. ***Altered mentation (GCS <=14)