ICU

Question 1

Define head injury

severity and %

Answer 1

trauma to the head other than superficial injuries to the face

Mild head injury makes up around 90% (GCS 13-15),

moderate 5% (GCS 9-12)

severe head injury 5% (GCS ≤8).

Question 2

Head injury how is autoregulation affected

Answer 2

head injury the normal autoregulation of cerebral blood flow (CBF) is lost

and

CBF becomes proportional to
cerebral perfusion pressure (CPP),

which in turn is directly determined by

both the mean arterial pressure (MAP) and the intracranial pressure (ICP):

CPP = MAP − ICP

Question 3

Target MAP in head injury

Answer 3

greater than 80-90 mmHg

until ICP monitoring is established,

and assumes that the ICP is 20 mmHg and

therefore ensures a CPP of at least 60-70 mmHg.

Question 4

Gold standard for ICP

Answer 4

An external ventricular drain (EVD) is perhaps the gold standard method of measuring ICP via an intraventricular catheter.

Question 5

Name some indications for CTB

Answer 5

The following indications for performing a head scan in head-injured patients are provided by the National Institute for Clinical Excellence (NICE) in the UK:

GCS less than 13 at any point since injury
GCS equal to 13 or 14 at two hours after injury
Suspected open or depressed skull fracture
Any sign of basal skull fracture
Post-traumatic seizure
Focal neurological deficit
More than one episode of vomiting, and
Amnesia of events, for greater than 30 minutes before impact.

Question 6

TPN

What is required

How is the nitrogen component given

Answer 6

The principles of total parenteral nutrition (TPN)

involve calculating 
nitrogen balance,
 energy, 
fluid and 
electrolyte requirements.

Question 7

TPN

what electrolytes should be given with tpn and how much per gram N

Answer 7

The nitrogen component should be given as mixtures of both essential and non-essential amino acids. 5-6 mmol of potassium and 1-2 mmol of magnesium (not calcium) are required per gram of nitrogen.

Question 8

TPN

how is carb given

How is fat given

Answer 8

Carbohydrate is usually given as glucose (10 to 50%), but other energy sources e.g. ethanol, xylitol and sorbitol have been used.

Fat is usually administered as 10 or 20% soya bean oil emulsion.

Trace elements and minerals must also be added.

Question 9

Metabolic complications of TPN include: x4

Answer 9

hypophosphataemia
hypernatraemia
hyperglycaemia, and
lipaemia.

Question 10

NIV and aerosol

is ppe required?

how can aerosols be reduced at commencement

where should patient be nursed

Answer 10

Whilst there is no evidence that NIV prevents invasive ventilation in H1N1 patients, it is commonly used as bridging therapy. It is important to remember that these are open circuits and still require personal protection for staff.

Ensuring that a well fitting mask is in place before airflow starts can reduce the amount of aerosol production. Similarly, avoiding water humidification and use of a closed hood is also advised.

Ideally patients should be nursed in a negative pressure room.

Question 11

HypoMagnesimia ECG changes

Answer 11

ECG changes of hypomagnesaemia are almost the same as those of hypokalaemia:

Flattening of T waves
ST segment depression
Prominent U waves
Prolonged PR interval, and
Prolonged QT interval

Question 12

Hypo Mg risks

Answer 12

Atrial and ventricular arrhythmia

Question 13

Affect of chronic hypomagnesaemia,

how may hypoMg occur

Answer 13

there is impaired synthesis and
release of parathyroid hormone (PTH),

and target organ response to PTH is impaired.

This produces secondary hypocalcaemia.

Hypomagnesaemia may result (like hypokalaemia) from the use of potassium ‘wasting’ diuretics (loop diuretics and thiazides, for example, furosemide).

Question 14

Diagnostic “ Berlin” criteria of ARDS include:

Answer 14

1) acute onset, meaning onset over 1 week or less

2)

bilateral opacities consistent with pulmonary edema must be present and may be detected on CT or chest radiograph

3)
PF ratio <300mmHg with a minimum of 5 cmH20 PEEP (or CPAP)

4)
“must not be fully explained by cardiac failure or fluid overload,” in the physician’s best estimation using available information - an “objective assessment” (e.g. echocardiogram) should be performed in most cases if there is no clear cause such as trauma or sepsis.

Question 15

The ARDSnet criteria recommend (vent parameters)

Answer 15

The ARDSnet criteria recommend

using tidal volumes of 6 ml/kg ideal body weight,

keeping plateau pressures <30 cmH2O,

using PEEP to optimise oxygenation

keeping the PaO2 above 8 kPa.

Question 16

Common criteria

Answer 16

Caused by 
sepsis, 
trauma, 
direct lung injury 
and pancreatitis.

Question 17

ARDS ddx and how it differs

x 3

Answer 17

Aspiration pneumonitis often preferentially affects dependent lung segments. Global, disseminated CXR changes are less likely than with ARDS.

Although basal atelectasis may account for some hypoxaemia it would not account for global CXR changes in middle and upper lung fields.

Cardiogenic pulmonary oedema is a key differential and can be diagnostically difficult to differentiate from ARDS as pulmonary artery catheters are rarely inserted. However, in this patient there is no history of acute cardiac disease and there is a good history of a common trigger for ARDS. Therefore ARDS is more likely than cardiogenic pulmonary oedema in this case

Question 18

The initiation of emergency renal replacement therapy is usually required for:

Answer 18

Acute life threatening hyperkalaemia which is resistant to treatment. In this example the potassium is within normal limits.

Development of metabolic acidosis which is non-responsive to fluid. In this instance the pH is within normal limits.

Development of fluid overload, which may manifest itself as pulmonary oedema.

Development of uraemia which may manifest itself as pericarditis (not pancreatitis), neuropathy and confusional state.

Question 19

Serotonin syndrome is characterised

Answer 19

Serotonin syndrome is characterised
by the triad of

1] altered mental status
(agitation, anxiety, restlessness and anxiety),

2] neuromuscular abnormalities
(tremors, clonus, muscle rigidity, akithisia and hyperreflexia)

3] Autonomic hyperactivity
(tachycardia, hypertension, sweating, hyperpyrexia, vomiting and diarrhoea).

It is most likely to develop within 24-hours of initiation of treatment.

Question 20

Serotonin syndrome is characterised

Answer 20

Serotonin syndrome is characterised
by the triad of

1] altered mental status
(agitation, anxiety, restlessness and anxiety),

2] neuromuscular abnormalities
(tremors, clonus, muscle rigidity, akithisia and hyperreflexia)

3] Autonomic hyperactivity
(tachycardia, hypertension, sweating, hyperpyrexia, vomiting and diarrhoea).

It is most likely to develop within 24-hours of initiation of treatment.

Question 21

Serotonin syndrome

Answer 21

Serotonin syndrome is a potentially life threatening adverse drug reaction that is a predictable consequence of excess serotonergic receptor agonism.

It produces a wide spectrum of clinical findings and commonly occurs within five weeks of commencing the drug

Patients with anticholinergic poisoning have normal reflexes, mydriasis, agitated delirium, urinary retention and hot, dry, erythematous skin

Question 22

Neuroleptic malignant syndrome

Answer 22

Neuroleptic malignant syndrome is an idiopathic reaction to dopamine antagonists and is defined by slow onset developing over a period of days to weeks. It is characterised by neuromuscular hypoactivity (rigidity and hyporeflexia).

Question 23

The RIFLE criteria uses changes in serum creatinine,

Answer 23

The RIFLE criteria uses changes in serum creatinine, GFR or urine output to categorise acute kidney injury into risk, injury and failure followed by loss and end stage categories for outcomes.

Risk correlates to:

creatinine increase of ×1.5
GFR decrease >25%, or
urine output <0.5 ml/kg/hr for six hours.

Injury correlates to:

creatinine increase of ×2
GFR fall of >50%, or
urine output <0.5 ml/kg/hr for 12 hours.

Failure correlates to:

creatinine increase of ×3
GFR fall of >75%
urine output <0.3 ml/kg/hr for 24 hours, or
12 hours of anuria.

Loss is complete loss of renal function for >4 weeks.

End stage is complete loss of renal function for >3 months.

Question 24

OD TCA

Answer 24

In overdose tricyclic antidepressants cause central nervous system and cardiovascular effects and should be suspected in the presence of a prolonged QRS. The combination of seizures, altered level of consciousness and cardiac toxicity is classical. These features are caused mainly by a combination of anticholinergic effects and the inhibition of re-uptake of norepinephrine and serotonin.

Alcohol intoxication can cause a metabolic acidosis and seizures but ECG changes are unlikely.

Seizures and altered level of consciousness may be a feature of opioid poisoning but pupils are more likely to be constricted and cardiac toxicity is not usually seen.

Diabetic ketoacidosis can cause a metabolic acidosis with elevated anion gap. It would be unusual for pupils and ECG to be affected.

Lithium toxicity is incorrect as a decreased anion gap is usually seen.

Question 25

The UK Resuscitation Council’s guidelines on the management of cardiac arrest in hypothermic patients differ slightly from the standard algorithm.

Answer 25

The UK Resuscitation Council’s guidelines on the management of cardiac arrest in hypothermic patients differ slightly from the standard algorithm.

In a patient with a core temperature below 30°C:

A total of 3 × DC shocks should be administered if on the shockable side of the algorithm (VF/VT)
Further shocks are not recommended until the patient is rewarmed to more that 30°C as the rhythm is refractory and so is unlikely to change
No drugs should be given as they will be ineffective.
In a patient with a core temperature between 30°C and 35°C:

DC shocks can be continued as normal
The time taken between drug doses should be doubled as they are metabolised much more slowly.
The patient should be actively rewarmed and protected against hyperthermia.

There is not enough information to know whether the resuscitation should be stopped so option e is false.