Intensive Care

Question 1

Critical care.

a) Basic principles
b) Levels of care - 1, 2 and 3
c) Staffing
d) Surgical vs medical

Answer 1

a) Support organs to buy time for disease-modifying treatment to take effect

b) Level 1 - ward level
Level 2 - HDU - single organ support (not intubated/ ventilated)
Level 3 - ITU - multiple organ support or intubated/ventilated

c) higher ratio of medical staff
- 1: 1 nursing in ITU (2:1 in HDU)

d) - 25% post op,
- 75% criticall unwell medical pts

Question 2

Criteria for ITU admission.

Answer 2

• Critically unwell with reversible pathology
  (so not end-stage metastatic cancer)
• Frailty, ADL independence (social history is vital)
• Need for organ support - something that can be offered in ITU that can’t be provided on the wards (eg. mechanical ventilation, inotropes)
• Patient consent/ famliy discussion - inform on process and likely outcome; give probability of returning to baseline or acceptable QoL

Question 3

Organ support: airway

Answer 3

Intubation.

• initially ETT; alternative = trache
• sometimes for airway protection (eg. anaphylaxis, head injury)
• usually in conjunction with mechanical ventilation for treatment of respiratory failure
• if > 14 days, consider tracheostomy (facilitates weaning); better tolerated than ETT so require less sedation, can comply with chest physio and easier to wean

Question 4

Organ support: breathing.

Answer 4

• Oxygen
• Ventilation
• Chest physio
• Positioning
• Nursing - secretions

Question 5

Organ support: circulation.

Answer 5

• Vasopressors
• Inotropes
• Pacemakers
• Intra-aortic balloon pumps

Question 6

Disability.

Answer 6

Neuro-protective measures to avoid secondary brain injury (eg. therapeutic hypocapnia to reduce ICP)

Encephalitis - protect agitated patient through sedation, enable investigations like CT/ LP

Refractory seizures (status) - may need RSI and I+V

Question 7

Renal replacement therapy.

a) Type in ITU
b) Indications (5)

Answer 7

a) Continuous veno-venous haemodynamic filtration
(CVV HDF)

b) Indications:
- Potassium - >6.5 refractory to medical mx
- Uraemic complications
- Metabolic acidosis
- Pulmonary oedema
- Other: toxins (eg. lithium, salicylates, ethylene glycol)

Question 8

Multi-organ failure.

a) Causes
b) Iatrogenic causes
c) Prognosis
d) Measurement tool for prognostication

Answer 8

a) - Single organ failure leads to cascade effect triggering multi-organ failure via…
- Haemodynamic, neurohormonal and cell signalling feedback

b) Mechanical ventilation - increases intra-thoracic pressure, compressing thoracic vessels thereby reducing preload and cardiac output
c) More organs failed = worse prognosis
d) APACHE II score

Question 9

Invasive monitoring and lines.

Answer 9

Arterial (art) line.

• Blood samples
• BP monitoring

Central venous lines.

• CVC
• PICC - can have for longer period, easier for ward based care management; inserted under US-guidance
• For giving drugs centrally (eg. NAd, TPN feeding)
• continuous CVP reading (normal: 3 - 8 mmHg) - historically used for assessing preload; not routinely used for this now

Vas-Cath.

• Special central line used for haemofiltration
• Has 2 lumens - one goes in, one comes out

Oesophageal doppler.

• Measures velocity of blood flow in descending aorta
• Gives estimate of cardiac output
• Good assessment of fluid status
• Give fluid boluses and/or inotropes to observe for fluid responsiveness (indicates hypovolaemia)

ECHO.
- Tells you cardiac function as a ‘snapshot’, so not continuous monitoring - possibly of less use if unstable patient

Question 10

Post-cardiac arrest care.

Answer 10

• Cardiac arrest in hospital or OOHCA
• ROSC achieved
• Exclude 4 Hs and 4 Ts
• CT head (exclude massive SAH or other intracranial pathology) and urgent cardiac catheterisation/ PCI
• Targeted temperature management*: 32 - 36 degrees achieved via cool fluids into CVC for 24 - 48 hours, with sedation to control shivering
• Protective ventilation - maintain normoxia and normocapnia
• Optimise haemodynamics: MAP, U/O, lactate, aim for normoglycaemia
• Diagnose and treat seizures - EEG, anticonvulsants, sedation
• Delay prognostication for 72 hours

*You’re not dead till you’re warm and dead (if arrest and very hypothermic, warm patient and give warm fluids, etc.)

Question 11

Recognition of a deteriorating patient (ITU candidate)

Answer 11

Threatened airway.

• eg. anaphylaxis, epiglottitis, head injury
• stridor, snoring, unresponsive, GCS <8 (or tolerating Guedel)

Respiratory failure.

• escalating oxygen requirements
• Life-threatening asthma
• New need for NIV for T1RF/T2RF
• Trauma chest injury score > 31

Refractory hypotension.

• Generally ~ 3L and no fluid responsiveness (eg. in septic shock)
• Indicates need for vasopressors/ inotropes

Severe head injury.
- Control of CO2 and BP to prevent secondary brain injury

DKA.
- Ketones > 6, pH < 7.1 , GCS < 12, hypotensive after initial fluid resus, significant comorbidities

Haemofiltration.
- Indications as above

Question 12

Prone ventilation.

a) Indication
b) Mechanism
c) Risks

Answer 12

a) Refractory hypoxaemia in ARDS

b) - Improves V/Q mismatch by increasing perfusion to dependent part of lung
- Decreases physiological shunt
- Decreases intra-thoracic pressure

c) - Labour intensive
- Can dislodge lines while turning

Question 13

ECMO.

a) Indication
b) Principles

Answer 13

a) Used when mechanical ventilation not sufficient to normalise Oxygen/ CO2

b) - Remove blood via central line
- Gas exchange occurs in machine (takes over job of lungs) - oxygenates and removes CO2
- Pumps oxygenated and decarbonated blood back into body