ICU drugs, IMV

Question 1

What do vasopressors do?

Answer 1

-Increase blood pressure

Question 2

What do inotropes do?

Answer 2

-Increase contractility of the heart

Question 3

What components of the cardiac cycle are linked in Frank-Starling law and how are they influenced by heart contractility?

Answer 3

-End-diastolic volume
-Pre-load
-Stroke volume
-Increased contractility –> increased SV and decreased EDV
-Increased EDV –> increased pre-load

Question 4

Why are inotropes and vasopressors only administered on ICU?

Answer 4

-Short half-life so must be given via infusion
-Given via central line
-Monitored using arterial line

Question 5

What are some examples of inotropes and what is their main serious risk / side effect?

Answer 5

-Dobutamine
-Dopamine
-Adrenaline
-Increased contractility = increased oxygen demand –> myocardial ischaemia –> MI

Question 6

What are some examples of vasopressors and what is the main serious risk / side effect?

Answer 6

-Noradrenaline
-Metaraminol
-Phenylephrine
-Adrenaline
-Work by causing smooth muscle contraction in the arteries –> arterial constriction –> increased after load –> increased work on heart + hypertensive episodes

Question 7

What 4 things can be manipulated in IMV to improve a patient’s ventilation?

Answer 7

CO2 removal - RR, tidal volume
O2 delivery - FiO2, PEEP (peak end expiratory pressure, prevents alveoli from collapsing)

Question 8

What complications can arise from IMV?

Answer 8

-Volutrauma / barotrauma
-Ventilator associated pneumonia
-Vocal cord trauma
-Tracheal stenosis
-Haemodynamic instability
-Delirium

Question 9

What are the functions of the kidney?

Answer 9

-Waste excretion
-Conversion of essential nutrients - amino acids, glucose
-Regulation of extracellular fluid - h2o, electrolytes, pH
-BP control - RAAS
-EPO production
-Drug metabolism + excretion

Question 10

What are pre-renal causes of AKI?

Answer 10

-Hypovolaemia / hypotension
-Abdominal compartment syndrome
-Renovascular disease

Question 11

What are some renal causes of AKI?

Answer 11

-Nephrotoxicity (drugs)
-Glomerular disease
-Haemolytic uraemia syndrome
-Hepato-renal syndrome
-Rhabdomyolysis

Question 12

What are some post-renal causes of AKI?

Answer 12

-Obstruction (stones)

Question 13

What 2 components are used to stage an AKI?

Answer 13

1. Serum creatinine
2. Urine output

Question 14

What are the diagnostic criteria for the different stages of AKI?

Answer 14

Stage I
-Cr = 1.5-1.9 x baseline OR >26.5mmol/l increase
-UO = <0.5ml/kg/h for 6-12h
Stage 2
-Cr = 2.0-2.9 x baseline
-UO = <0.5ml/kg/h for >12h
Stage 3
-Cr = >3.0 x baseline OR > 353.6mmol/l increase
-UO = <0.3ml/kg/h for >24h OR anuria for >12h

Question 15

How should AKI be managed?

Answer 15

1. Treat obstruction (diagnose on USS / CT KUB)
2. Treat hypovolaemia (fluids)
3. Optimize BP
4. Stop nephrotoxic drugs
5. Investigate and treat any underlying cause eg vasculitis

Question 16

What are the main indications for RRT?

Answer 16

AEIOU
-Acidosis
-Electrolyte imbalance eg persistent hyperkalaemia
-Ingestion of toxins (alcohol, lithium)
-Overload of fluid
-Uraemic symptoms (encephalopathy, pericarditis)

Question 17

What are some complications of RRT?

Answer 17

LINE-RELATED
-Vascular injury / thrombosis
-Infection
ANTICOAGULANT RELATED
-Hypocalcaemia
-Bleeding
-Thrombocytopenia
CIRCUIT RELATED
-Air embolism
-Clotting
-Anaemia
-Thrombocytopenia
-Hypothermia
-Hypovolaemia
-Electrolyte imbalance