This hot case is usually not about the aetiology of weakness, but rather about its influence on the overall management strategy. It may be integrated with the topic of weaning from ventilation.
If the candidate is invited to offer a diagnosis (or discuss a diagnostic strategy), they would do well to remember the general approach to the patient with weakness. Below is an abbreviated table of possible aetiologies, organised by level of dysfunction.
Previous hot cases with this sort of theme to them can be found below.
|Level of pathology||Aetiology|
|Motor neuron||Motor neuron disease (eg, amyotrophic lateral sclerosis)|
|Spinal cord||Transverse myelitis|
|Compression by tumour|
|Compression by abscess|
|Spinal cord infarction|
|Peripheral nerve||Critical Illness Neuromyopathy|
|Vitamin B12 deficiency|
|Heavy metal poisoning|
|Neuromuscular junction||Myasthenia gravis|
|Atophy due to hypercatabolic state and malnutrition|
|Critical Illness Neuromyopathy|
The standard introduction
Ask examiners about turning up the lights
The physical examination
The details of this section can be seen in the opposite column.
The obs and investigations
The Physical Examination in Brief Detail
Ask the examiners to sit the patient up
Ask the examiners about any language barriers
Ask examiners to lay the patient flat.
Sit the patient back up again
One can ask the examiners the following questions:
One should ask about the following parameters:
One should ask to look at the pressure-volume loops.
The ventilation strategy offers a clue as to the degree of weakness.
Is the patient fully supported on a mandatory mode? Are they able to trigger? Is NAVA ventilation in use?
There may be surgical drains (what is in them? How much of it?). Asking how much has been coming out may be relevant in a hot case which focuses on the diagnosis of a shock state.
The pleural catheters are also interesting. One should make a mental note of whether the ICCs are on free drainage or on suction. The content of these drains could be informative, especially if one notices blood or chyle.
A CVVHDF or SLEDD process may be in progress. The savvy candidate may wish to ask the following questions:
These questions may go unanswered.
The patient you are examining may have some sort of extra gadget hooked up. If ECMO is in progress, one may wish to ask about the following parameters:
If IABP counterpulsation is in progress, it raises additional questions. One may wish to ask the examiners whether one may be able to switch it to 1:2, to assess the efficacy of augmentation.
This stage is critically important. The drug and fluid infusions which are currently in progress give a clue as to what problem is currently being addressed. One should not neglect the labelled bags; the choice of antibiotics gives one some idea of where the source of sepsis is thought to be.
A bottle of IV immunoglobulin may be present, carelessly left to dangle where the candidate can see it. Suspicion of autoimmune demyelination develops.
One should observe the following features of an EVD:
Ideally, one should get the patient sitting up to 30-45°. This may not be possible. However, one should still ask for it.
Ideally, the patient should be exposed from the waist up. The candidate can then stand back and look for anything externally obvious:
Performing the GCS should be the first step. The patient should be reasonably conscious - otherwise the examination of their weakness would be rather pointless.
A traditionalist, who is examining Mr Bloggs, would approach the GCS in the following manner:
One has just performed a GCS assessment; one is still holding the hands.
Now, time to look at them more closely.
First, one should spent a second assessing whether they are warm or cold.
Then, one can focus on the nails. Nail signs are numerous and deserve their own page.
In brief, the nail signs one could look for are as follows:
Done with the nails, one may want to briefly consider (and maybe even comment upon) the presence of any sort of characteristic deformities, eg. assymetrical wasting of the small muscles, or the joint changes of rheumatoid arthritis.
Next comes the pulse. While one still has both of the patient's hands, one ought to try to compare the radial pulses. It would be worthwhile to look up at the arterial line trace at this stage; abnormalities such as the widened pulse pressure of aortic regurgitation may not have been noticed until this stage.
Tone of the upper limbs
Move up from the hands. While you are still holding the hands, you can perform a sort of gross examination of tone by pronating and supinating the wrists, and by flexing and extending the elbows.
It may be possible to assess asterixis by asking the patient to hold both their arms up with the wrists dorsiflexed. The weak patient may not be able to perform this trick - they cannot lift their arms.
Examine the cubital fossa for
One should then palpate the axillary lymph nodes.
Palpate the neck:
Ask the patient to lift their head off the bed.
The weakness hot case patient will likely be fully conscious. Therefore, one needs to spend a reasonable time examining their cranial nerves in satisfactory detail.
|The upper cranial nerves||The lower cranial nerves|
A Snellen chart is ideal, but probably will not be available.
The extubated patient should be able to read the time on the clock in the room.
One performs this test with each eye individually.
This tests CN II.
Ask the examiners to dim the room lights.
Open both eyes. Each eye is exposed to light. The opposite pupil should constrict consensually.
This tests CN II (afferent) and CN III (efferent).
The cornea (not the sclera) is touched lightly with a moistened corner of a piece of gauze.
A normal reflex is to blink.
This tests CN V (afferent) and CN VII (efferent)
The conscious patient will be able to follow the tip of the candidate's finger.
The pattern of movements should be tracing the six cardinal points: superior left, inferior left, superior center, inferior center, superior right, inferior right.
This tests CNs II, IV and VI.
Typically, this is performed by putting some pressure on the superior orbital notch.
The patient should either open their eyes or localise.
This tests CN V.
Again, it is important to ask for permission before doing this. Sometimes a simple light touch test would be more appropriate.
The conscious patient will be able to perform a series of grimaces to assess the bilateral motor control of facial muscles:
Now that one has finished with the upper cranial nerves, one can move on to the mouth, airway, and swallowing apparatus.
The Yankeur sucker is used to probe the posterior pharynx, on both sides. A gag reaction should result from this.
This collectively tests CN X and IX.
While on the subject of CN X, one may test the cough reflex by suctioning the trachea.
This tests CN X.
This is also a convenient time to ask about the volume and character of the secretions.
The conscious patient is asked to protrude their tongue, and move it from side to side.
This tests CN XII.
The uvula deviates away from the lesion.
This tests CN X and IX.
The conscious patient is asked to shrug their shoulders against resistance.
This tests CN XI.
During the cranial nerve examination, one will inevitably end up tripping over the endotracheal tube. One should note whether there is anything unusual there; for instance, is there a dual-lumen tube, or a bronchial blocker?
The tracheostomy should not be neglected, with particular attention being paid to the cuff (is it deflated?)
One puts both their hands on the chest to assess the symmetry of chest expansion. A unilateral phrenic nerve paralysis may be a clue to an intrathoracic malignancy, as a cause of a paraneoplastic weakness syndrome.
One might wish to percuss the chest.
Changes in percussion resonance may be worth commenting on.
One may begin by auscultating the apices anteriorly. Then, one should auscultate as posteriorly as possible. The money is in the bases.
The clever candidate will make a big show of palpating both the apex and the right sternal edge.
One should auscultate in the following sequence:
The various clicks and murmurs one encounters are discussed elsewhere.
For this, one should ask to lay the patient flat.
The pelvic content would have been palpated during the abdominal examination.
The more important part of this examination is the groin.
At this stage, the patient should be re-draped - cover them from the waist up, and uncover their legs.
Observation and palpation of the pelvis:
Examination of the lines
Examination of the genitals and rectum
Once one is finished with the pelvis, one should cover it again, so that only the legs are sticking out.
One should ask to remove TEDs and compression stockings.
Leg muscle tone
The best way to test muscle tone is by holding the knee. Roll the knee gently to distract the patient; then try to lift it off the bed. In the presence of increased tone, the leg will remain straight and the whole thing will lift up; with normal or decreased tone, only the knee will bend
In the conscious patient, one might be able to assess whether a gentle calf squeeze produces the characteristic pain which suggests a DVT may be present.
This brings one to the feet, and to the beginning of the neurological examination.
The feet would have already been palpated to assess their temperature, and to look for pitting oedema.
Observation of the feet
One should look specifically for changes suggestive of chronic diabetic foot disease, or chronically poor vascular supply.
Palpation of the feet
This should consist of palpating the dorsalis pedis and posterior tibial pulse.
One should test the Babinsky bilaterally.
One should attempt to assess clonus in both feet.
Now is the time to properly start the neurological examination of this patient.
Power of the muscle groups may be tested in the following sequence:
The patient has spent most of this time flat and supine. Time to sit them back up again.
Power of the upper muscle groups may be tested in the following sequence:
Now that one is back to the upper limb, one may as well start their reflex tests there.
The reflexes may be tested in the following order:
After testing the ankle jerk reflex, one is again back to the feet.
At this stage, with a conscious patient, one may wish to test light touch sensation.
The following order (with corresponding dermatomes) is suggested:
Now, usually, the cerebellum requires all sorts of dynamic manoeuvres- one should assess the gait, balance, speech, and so forth. The intubated ICU patient does not permit the majority of these. They are so entangled in tubes they may not be able to perform dysdiadochokinesis.
The following is a list of cerebellar tests one may be able to perform with an intubated ICU patient.
Many of these findings would have been discovered during earlier stages of the examination.
The weakness hot case patient may not be able to perform many of these tests. However, cerebellar dysfunction and incoordination may form a part of their stroke syndrome, and thus it would be unwise to omit this part of the examination.
This would have become apparent during the testing of the eye movements.
This would have become apparent during the test for nystagmus
This is an assessment of coordination. The patient is asked to alternate between touching their nose and touching the finger of the candidate, who keeps changing its position.
The patient is asked to run the heel of one foot along the shin of the opposite leg.
Ask to see the obs chart. If it is not allowed, ask for the following:
One may also wish do demonstrate an interest in the trends of any sort of advanced haemodynamic monitoring, eg. cardiac index as measured by PAC or PiCCO
One needs to show an interest in the following labs:
Also, one might wish to show some interest in the routine investigations:
One should always ask for the following:
"Mr Bloggs' weakness is likely due to [insert clever diagnosis here]."
"I have come to this conclusion on the basis of the following findings: [insert clinical findings here]"
"I would like to confirm my diagnosis with the following investigations: [insert appropriate investigations]"
"The current management issues are as follows: [a brief list of management priorities]"
"I would approach the management of these issues in the following manner: [list of management strategies; it helps to organise this into an A,B,C,D,E approach if one has a complex multisystem problem to manage]"
”Mr Bloggs' weakness is likely multifactorial."
"During my examination, I noted the following clinical signs [list of features]."
"On the basis of these, I have arrived at the following list of differentials: [insert list of differentials]."
"In order to discriminate between these differentials, I would like to perform the following investigations: [list of investigations]"
"Furthermore, I would like to enlist the help of the following specialties [insert list of consults], for whom I will have the following specific requests/questions: [what questions will you ask these specialist teams]"
"While working on a diagnosis, I will offer the following supportive management [blah]"