Intensive Care

Question 1

What is the incidence of erosive oesophagitis in mechanically ventilated patients?

Answer 1

48%

due to:
NG tube
GI reflux
Bile reflux

Question 2

What is the incidence of diarrhoea in mechanically ventilated patients?

Answer 2

Approximately 50%

due to:
NG feeding at high rates
Hyperosmotic feed
Small bowel bacterial growth

Question 3

What are the risk factors for acute acalculous cholecytitis in ITU patients?

Answer 3

Dehydration
Sepsis
Shock
Blood transfusion
Extended fasting
TPN

Question 4

What are the Berlin criteria for ARDS?

Answer 4

• Acute onset (less than a week)
• Bilateral infiltrates suggestive of pulmonary oedema
• PF ratio of less than 40kPa or 300mmHg with at least 5cmH2O PEEP
• Not explained by cardiac failure or fluid overload

Mild = P/F ratio (using mmHg) of 200-300
Moderate = P/F ratio 100-200
Severe = <100

Question 5

What do the ARDSnet criteria recommend for ventilating ARDS?

Answer 5

Tidal volumes 6ml/kg using ideal body weight
Plateau pressures less than 30cmH2O
PaO2 >8kPa but avoid hyperoxia
Use PEEP to optimise oxygenation
Recruitment manoevures
Permissive hypercapnoea aiming for pH greater than 7.2

Question 6

What are the functions of the pancreas?

Answer 6

Exocrine
- 1500ml Pancreatic digestive fluid per day
- Bicarbonate
- Electrolytes
- Proteolytic enzymes

Endocrine
- Insulin
- Glucagon
- Somatostatin

Question 7

What are the signs and symptoms of acute pancreatitis?

Answer 7

Epigastric pain
Vomiting
Fever
Abdominal distension
Peritonism
Grey-Turner’s sign (Flank discolouration)
Cullen’s sign (Umbilical discolouration)
Fox’s sign (Inguinal ligament discolouration)

Question 8

What are the common causes of acute pancreatitis?

Answer 8

Idiopathic

Obstructive
- Gallstones
- Neoplasm
- Chronic alcohol use
- Cystic fibrosis

Parenchymal
- Trauma
- ERCP

Systemic
- Hypoxia
- Sepsis

Toxic
- Acute alcohol use
- NSAIDs
- Hypothermia
- Hypercalcaemia

Question 9

What are the strong indicators for intensive care admission for acute pancreatitis?

Answer 9

Age >70
BMI >30
Three or more Ranson’s criteria
30% necrosis of the pancreas
Not responding to fluid resuscitation
Pleural effusions

Question 10

How does proning help in management of ARDS?

Answer 10

Improved ventilation perfusion matching
Aids in recruitment of collapsed lung units, particularly by reducing compression of lung tissue by the heart
Increased functional residual capacity
May also help to drain secretions

Question 11

What are the Murray criteria for referral for ECMO?

Answer 11

P/F ratio on 100% oxygen
PEEP
Number of Quadrants with consolidation
Lung compliance

MDCalc also has an option for whether patient is COVID-19 positive

Question 12

What are the contraindications to ECMO?

Answer 12

High peak airway pressures over 30cmH2O for more than a week
FiO2 greater than 80% for more than a week
Intracranial bleed
Other contraindication to anticoagulation

Question 13

What type of ECMO circuit is usually used for respiratory disease with preserved cardiac function?

Answer 13

Veno-Venous ECMO

Question 14

What are the parameters measured by the APACHE II score?

Answer 14

GCS
Haematocrit
Temperature
Mean arterial pressure
Heart rate
Respiratory rate
Arterial pH
PaO2
Sodium
Potassium
Creatinine
White cell count

Question 15

What are the metabolic complications of TPN?

Answer 15

• Hypernatraemia
  
  • Hyperglycaemia
  • Lipaemia
  • Hypophosphataemia

Question 16

How much potassium and magnesium is required per gram of nitrogen in TPN?

Answer 16

• 5-6 mmol potassium and 1-2 mmol magnesium are required per gram of nitrogen

Question 17

What are the steps of hyperoxic lung damage?

Answer 17

Initiation phase - reactive oxygen species production

Inflammatory phase - surfactant disruption, epithelial and endothelial damage, pulmonary oedema, increased cytokine production and activation of the immune system

Proliferative phase - activation of the clotting cascade

Fibrotic phase - permanent lung damage

Question 18

Why is hyperoxia of use in carbon monoxide poisoning?

Answer 18

In CO poisoning you can have a normal PaO2, but very little oxygen bound to haemoglobin as it has all been displaced by CO

The half life of CO-haemoglobin is 5 hours in room air
This drops to 90 minutes when high FiO2 oxygen is applied

This drops further to 20minutes in a hyperbaric chamber at 3 atm*

*The current evidence can’t determine whether this is a good idea, or whether we should just stick to high concentrations at normal pressures, because adverse neurological outcomes means there isn’t an obvious benefit to hyperbaric therapy.

Question 19

What adverse effects can hyperoxia have in neonates?

Answer 19

Retinopathy
Bronchopulmonary dysplasia

Question 20

What are the risk factors of hyperoxia in each age category?

Answer 20

Neonates and Infants

Risk of bronchopulmonary dysplasia
Reduced patency of ductus arteriosus
Increases systemic vascular resistance
Increased atelectasis and reduced FRC
Increased cerebral vascular ischaemia
Reduced cerebral blood flow
Increased oligodendrocyte apoptosis

Adults

Reduced coronary artery flow
Increased ischaemic injury
Reduced sensitivity of carotid body chemoreceptors

Elderly

Worsening of neurodegenerative disorders
Worsening of stroke
Increased airway inflammation in COPD
Diaphragmatic dysfunction