Critical Care Medicine

Question 1

what reduces risk of ventilator-associated pneumonia?

Answer 1

• head of bed elevated at least 30 degrees
• daily sedation interruption and assessment of readiness to extubate
• ETT with subglottic suction
• early exercise or mobilisation
• change ventilation circuits only if malfunctioning or visibly soiled

Question 2

what reduces risk of CLABSI?

Answer 2

• hand hygiene
• maximal barrier precautions
• chlorhexidine skin antisepsis
• avoid femoral access
• daily review of line necessity

Question 3

how to calculate MAP?

Answer 3

2 x diastolic + systolic pressure

divided by 3

Question 4

How to improve oxygenation?

Answer 4

increase FiO2 or increase PEEP (to open up collapsed/flooded alveoli)

Question 6

what scoring system is used to help identify patients on high flow oxygen who are at low or high risk for intubation?

Answer 6

ROX index
- defined as the ratio of SpO2/FiO2 (%) to respiratory rate (breaths/min)

Question 7

indications for CPAP?

Answer 7

OSA
Pulmonary oedema
Excessive dynamic airway collapse
Preintubation/ postextubation

Question 8

indications for BIPAP?

Answer 8

COPD exacerbation
Obesity hypoventilation syndrome
Neuromuscular disorders

with ST mode (minimum set respiration): hypoventilation, central apnoeas

Question 9

first choice vasopressor/inotrope for cardiogenic shock without hypotension?

Answer 9

dobutamine

-> increases inotropy
- add on therapy for distributive shock with depressed cardiac function

Question 10

what inotrope is indicated for use in cases of severe bradycardia in septic shock?

Answer 10

dopamine (high dose)

Question 11

what inotrope is first choice in anaphylactic (distributive) shock?

Answer 11

adrenaline
- increases SVR, inotropy
- can be added to noradrenaline in septic distributive shock

Question 12

first choice inotrope in cariogenic, distributive and hypovolaemic shock?

Answer 12

noradrenaline

Question 13

Definition criteria of ARDS?

Answer 13

1. onset within 1 wk of known ARDS insult
2. Bilateral opacities on chest imaging consistent with pulmonary oedema
3. Respiratory failure not related to cardiac failure or volume overload
4. PF ratio <300 on at least PEEP of 5 from NIV/invasive ventilation

Question 14

severity of ARDS is based on?

Answer 14

mild: PF ratio 200-<300
Moderate: 100-200
Severe: <100

Question 15

what tx is beneficial for ARDS?

Answer 15

• Low Tidal volume
• Prone positioning 12-16h/day
• ECMO for those with severe refractory ARDS

Question 16

Strategies to prevent postoperative atelectasis?

Answer 16

pain control, early mobility, secretion management with aggressive chest PT

Question 17

when to offer ECMO for patients with acute exacerbation of idiopathic pulmonary fibrosis?

Answer 17

only offered as a bridge to lung transplant

-> outcomes after intubation and mechanical ventilation are very poor for patients with acute exacerbation of IPF, need to discuss goals of care/ palliative care strategies early

Question 18

why does hypercapnic T2RF occur?

Answer 18

Alveolar hypoventilation
due to
1) decreased respiratory drive
e.g. central apnoea, OHS, drugs, hypothermia/ hypothyroidism, stroke, meningitis
2) low tidal volume or increased dead space relative to overall tidal volume
e.g. Neuromuscular weakness, obstructive airway disease, restrictive physiology

Question 19

obesity hypoventilation syndrome is characterised by?

Answer 19

obesity + sleep disordered breathing + persistent daytime hypercapnia (pCO2 >45)

Question 20

what ix is helpful in assessing neuromuscular weakness as a cause of hypercapnic respiratory failure?

Answer 20

evaluation of maximum inspiratory and expiratory pressures (usually <50% of predicted)
+
positional changes in vital capacity (usually >20% decrease in FVC while supine)

Question 21

what are the 3 criteria of the qSOFA score?

Answer 21

1. RR >22 = 1 point
2. SBP <100 = 1 point
3. Altered mental status = 1 point

2 or more in the setting of known or suspected infection predicts increased mortality

Question 22

criteria for diagnosing septic shock?

Answer 22

• serum lactate > 2 despite adequate fluid resus

+
hypotension requiring vasopressors to maintain a mean arterial pressure of > 65 mmHg

Question 23

what is the dose of hydrocortisone recommended by 2016 surviving sepsis campaign for refractory shock?

Answer 23

200mg daily

Question 24

management options of nonexertional heat stroke?

Answer 24

evaporative cooling (water mist/ fans) with or without ice packs to lower core temp

Question 25

management of exertional heat stroke?

Answer 25

evaporative cooling
+
may require immersion in ice water

Question 26

malignant hyperthermia occurs when?

Answer 26

in people with rare, autosomal dominant derangement in intracellular calcium metabolism that causes severe hyperthermia in response to inhaled anaesthetic agents such as halothane and isoflurane or the depolarizing paralytic succinylcholine

Question 27

treatment of malignant hyperthermia?

Answer 27

discontinuation of triggering agent
active cooling
muscle relaxant dantrolene - administer every 5-10min until muscle rigidity and hyperthermia resolve

Question 28

symptoms/features of malignant hyperthermia?

Answer 28

muscle rigidity, rhabdomyolysis, cardiac arrhythmias, core body temp elevation to 45 degrees celsius or greater

Question 29

Neuroleptic malignant syndrome may be triggered by?

Answer 29

antipsychotic agents e.g. haloperidol, antiemetics
- usually Assoc w dopamine receptor blockade

Question 30

features of neuroleptic malignant syndrome?

Answer 30

tetrad of fever, mental status changes, muscle rigidity, dysautonomia

Question 31

tx of neuroleptic malignant syndrome?

Answer 31

withdrawal of triggering agent (or reinstating the withdrawn dopaminergic agent)
active cooling
rehydration with IV fluids
dantrolene/ bromocriptine

Question 32

features of serotonin syndrome?

Answer 32

mental state changes, dysautonomia, hyperthermia, hyperreflexia, other muscle abnormalities

Question 33

mx of serotonin syndrome?

Answer 33

removal of offending agent
supportive care
benzodiapines or off label cyproheptadine

Question 34

Answer 34

ECG showing Osborne waves associated with hypothermia

• best seen in the inferior and lateral chest leads.
• osbourne waves defined by the shoulder or “hump” between QRS and ST segments

Question 35

what alcohol toxicity leads to blindness?

Answer 35

methanol poisoning
- as methanol is metabolized to formic acid, which is toxic to the retina and leads to blindness

Question 36

which alcohol poisoning leads to permanent kidney damage due to metabolites?

Answer 36

ethylene glycol poisoning
- due to metabolization to oxalic acid which crystalizes in renal tubules an dcan lead to permanent renal damage