assessing fluid status

1. central venous pressure
2. capillary refill time
3. pulse rate
4. blood pressure
5. urine output
6. skin turgor
7. mucous membrane
8. sunken eyes
9. decreased GCS

hypoxia – where is the underlying problem

1. respiratory centres – brainstem, cerebral lesions
2. phrenic nerve – diaphragm muscles
3. spinal nerve – intercostal muscles
4. ventilation
5. perfusion – PE, pneumonia (vasoconstriction in response to hypoxia)
6. diffusion – 1. surface area (emphysema); 2. nature of membrane (pulmonary oedema, fibrosis, atelectasis); 3. diffusion gradient
7. intrapleural – inflammatory, infective

post extubation x-ray

rationale

• collapse of lung
• consolidation
• sputum

post-extubation, ventilation is dependent on patient’s respiratory abilities. respiratory exchange problems can be masked by intubation and manifest post-extubation (if lesions not resolved)

central line – why is it bad to have it put right into RA

• irritation of RA –> AF
• erosion of RA
• tricuspid valve damage
• endocarditis (if unsterile)

central line – where should the tip be?

T4

halfway between aortic knuckle

causes of pulseless electrical activity (PEA) / electrical-mechanical dissociation (EMD)

Pulseless electrical activity (PEA) / electrical-mechanical dissociation (EMD) = presence of ecg trace but no cardiac output (hence pulseless)

Causes – 5H, 4T

• Hypokalaemia
• Hypovolaemia
• Hypoglycaemia
• Hypoxia
• Hypothermia

• Tamponade
• Tension pneumothorax
• Thromboembolism
• Toxins

complications of blood transfusion

• bacteria infection
• viral infection (hep C 1in400; HIV 1in1million)
• prion disease
• malaria

• transfusion related acute lung injury
• transfusion related immune modulation (cytokines released by white cells)
• blood group mismatch (ABO incompatibility)
• anaphylaxis

• hypercalcaemia (citrate binds to Ca++)
• hyperkalaemia (transfusion of loads of old blood)
• preservatives (leading to acidosis)
• hyperthermia (?)

• Hb can poison kidneys
• coagulopathy
• fluid overload

what’s leaking from the nose? differentiating between CSF from other secretions

1. double ring sign – place 1ml of fluid on absorbent filter paper; if csf = central circle of blood and outer clear ring of csf
2. dipstick – absence of glucose excludes csf (presence of glucose is not diagnostic since nasal secretion and tear contain glucose as well). presence of protein

note:

csf -

• protein 20-40mg/dL; glucose 50-100mg/dL

base of skull fracture

clinical features

1. periorbital bruising (racoon’s eyes)
2. haemotympanum (blood leaking from ear) or otorrhoea (CSF leaking from ear)
3. mastoid bruising (battle’s sign)
4. rhinorrhoea (CSF from nose)

positive end-expiratory pressure

Good/importance

• decreases preload (if hypervolaemic)
• prevent alveolar collapse
• decreases work of inspiration (since alveolar is opened)
• prolong alveolar opening time (hence increase time for gaseous exchange)

Bad

• decreases venous return (nil PEEP if hypovolaemic)
• high PEEP associated with barotrauma

ventilation without PEEP is bad

ventilation with high PEEP is bad