The Renal Failure Patient on Dialysis

The objective is to assess the patient, and answer certain questions:

  • Is the renal failure acute or chronic?
  • Is it pre-renal, intrarenal or post-renal failure?
  • What are the goals of dialysis?
    • What is the fluid balance?
    • What is the acid-base status?
    • What is the electrolyte picture?

Previous hot cases with this sort of theme to them can be found below.

A Structured Approach to the Renal Failure Patient

The standard introduction

  • The examiner will give you a history.

The prelude to the dance

  • Wash hands.
  • Gown and glove.
  • Ask, if relevant:
    • "Can I turn on all the lights?"
    • "Are there any movement restrictions? Can I sit them up, or roll them on their side?"
    • "Is there a language barrier?"
  • Introduce yourself: “Hi Mr or Mrs Bloggs, I’m Dr So-and-so. I’m going to examine you.”

The Monitors

  • Rhythm
  • Rate
  • Morphology: QRS width
    • Specifically, one might want to note the height of the T wave, in case the patient has a ridiculously high potassium level.
  • MAP and abnormal morphology of the arterial waveform
  • CVP and abnormal morphology of the CVP waveform
    • Though crude, the CVP may offer a vague impression of the fluid status.
  • Ancillary waveforms eg. the PA catheter waveform
  • Oxygen saturation measurement, and the quality of the waveform
  • End-tidal CO2 waveform and level

A pacing box?

  • Pacing mode
  • Set rate

Sensitivity and pacing threshold may not be relevant.

The Ventilator

One can ask the examiners the following questions:

  • How are we oxygenating this patient?
  • How are we ventilating this patient?
 

One should ask about the following parameters:

  • FIO2
  • PEEP
  • Peak pressure
  • Plateau pressure
  • Tidal volume and minute volume

One should also ask to look at the pressure-volume loops.

Urine catheter

  • Unusual colour
  • Anuria
  • Oliguria

It would be nice to ask what the urine output has been over the last 24 hours.

The urine may be coming out of a nephrostomy tube, or there may be a bladder irrigation set.

Drains (surgical, intercostal, etc)

There may be surgical drains (what is in them? How much of it?).

An abdominal catastrophe may be the cause of renal failure.

Dialysis

A CVVHDF or SLEDD process may be in progress.

The savvy candidate may wish to ask the following questions:

  • Which modality is being used?
  • What is the dose of dialysis?
  • What is the rate of fluid removal?
  • How is the circuit anticoagulated?
  • How long has this filter lasted?

It would be good to note exactly what is in the dialysate bags.

IABP / ECMO

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:

  • VA or VV?
  • Flow rate
  • Fresh gas flow
  • Any recent problems with the circuit

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.

Furthermore, the IABP- if the balloon is too low - may actually be responsible for the renal failure. One should make a mental note of this for the presentation.

Infusions

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.

Specifically in renal failure, one should take notice the following drugs:

  • N-acetylcysteine (for contrast-induced nephropathy)
  • Sodium bicarbonate (to alkalinise the urine, for rhabdomyolysis)
  • Frusemide infusion (to drive diuresis, eg. in cyclophosphamide therapy)
  • Rasburicase (to promote urate elimination in tumour lysis syndrome)

EVD

One should observe the following features of an EVD:

  • Set height
  • Whether it is open or closed
  • The CSF colour - eg. is it full of blood?

Weird machinery

A MARS system or plasmapheresis apparatus may be in the room.

The latter is more likely, and might give the candidate the impression that some sort of autoimmune catastrophe has wiped out the kidneys.


The physical examination

Expose and observe

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:

  • Skin colour, eg. jaundice or the discolouration of chronic renal failure
  • Muscle wasting, obesity
  • The evidence of trauma, wound dressings, etc
  • The pattern of breathing (eg. whether there is a characteristic chest flail)
  • The effort of breathing (eg. the laboured Kussmauling of uncorrected metabolic acidosis)

GCS

Performing the GCS should be the first step, unless you notice that a neuromuscular junction blocker is among the infusions. The level of consciousness then determines how you go about examining the rest of the patient.

A traditionalist, who is examining Mr Bloggs, would approach the GCS in the following manner:

  • Grab hold of both of the patient's hands.
  • "Mr Bloggs!" One pauses to observe for eye opening.
  • "Can you squeeze my hands?"
  • If hand squeezing and eye opening is not observed, one administers a painful nail bed stimulus to both hands, to observe the response to pain.

Hands, nail signs, pulse and the arterial line.

  • Characteristic deformities, eg. assymetrical wasting of the small muscles, or the joint changes of rheumatoid arthritis.
  • Radial pulse

Arms

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.

Asterixis

In the conscious patient, it may be possible to assess asterixis by asking the patient to hold both their arms up with the wrists dorsiflexed.

Palpate the arms:

  • Examine the cubital fossa for
    • Peripheral lines
    • Evidence of multiple venepunctures
    • Lymph nodes
    • Brachial pulse
    • The presence of an obvious AV fistula

One should then palpate the axillary lymph nodes.

The Neck

  • Inspect any central lines
  • Look again at the CVP

Palpate the neck:

  • Trachea: is it midline? Is there a new tracheostomy there?
  • Thyroid gland
  • Cervical lymph nodes
  • Carotid pulse - one side at a time!
  • Submandibular lymph nodes
  • Pre- and post-auricular lymph nodes

Pupils and the higher cranial nerves

The renal failure patient's cranial nerve examination may be irrelevant.

In the unconscious patient, one might wish to limit oneself to the examination of the pupillary light reflex.

Light reflex

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).

Airway and the lower cranial nerves

The airway is also of peripheral interest in the examination of the renal failure patient.

Gag reflex

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.

The purpose of doing the gag reflex in a renal failure hot case is actualy to look at the posterior pharynx. One might discover the red raw tonsils of a streptococcal pharyngitis, which will change the tone of one's discussion of possible aetiologies.

Cough reflex

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. A patient with severe pneumonia may develop renal failure as a consequence of sepsis. A patient with pulmonary haemorrhage and bloody tracheal aspirates may have Goodpasture's syndrome, or some other sort of vasculitis.

Chest palpation, percussion and auscultation

Palpation:

One puts both their hands on the chest to assess the symmetry of chest expansion.

Percussion:

One might wish to percuss the chest.

Changes in percussion resonance may be worth commenting on.

Large pleural effusions may be present, and this adds to the fluid balance asssessment, but they would not be obvious unless the patient is well enough to sit up.

Auscultation:

One may begin by auscultating the apices anteriorly. Then, one should auscultate as posteriorly as possible. The money is in the bases. During the discussion of fluid management, one needs to be armed with the presence or absence of pulmonary oedema as one of the findings.

Palpation and auscultation of the praecordium

Cardiac failure may be a major contributor to the renal failure.

Palpation:

The clever candidate will make a big show of palpating both the apex and the right sternal edge.

Auscultation:

One should auscultate in the following sequence:

  • Apex
  • Left sternal edge, lower
  • Left sternal edge, upper
  • Right sternal edge, lower
  • Left sternal edge, upper
  • Both carotids

The various clicks and murmurs one encounters are discussed elsewhere.

One should make a point of looking for a pericardial rub, and for pericardial effusion.

Abdominal palpation, percussion and auscultation

For this, one should ask to lay the patient flat.

Abdominal observation

  • Take a moment to behold the abdomen. One may ask the examiners to look under any surgical dressings; one is likely to be denied this part of the examination (they will tell you the wound looks clean and dry).

Abdominal palpation

  • All quadrants should be palpated.
  • Then, feel for the liver edge; observe respiratory excursion
  • Then, feel for the spleen.
  • Then, try to ballot the kidneys. Enquire about renal tenderness.
  • Palpate for aortic aneurysm. One must keep it in mind as a cause of renal failure; however, more often it is the attempted repair which is responsible.

Abdominal percussion

  • This can double as a test for peritonism.
  • If there is some suspicion of ascites, one may ask to roll the patient, so shifting dullness can be better appreciated. The examiners may not permit this test.

Abdominal auscultation

  • One should spend a good length of time on this, if one suspects bowel obstruction or ileus.
  • In the renal failure hot case, a good place to listen is a few centimetres above the umbilicus, pressing firmly, where one can sometimes detect a renal artery bruit.

If the abdomen is distended or there is obvious evidence of surgical invasion, one may wish to ask about the intra-abdominal pressure, or more directly about the renal perfusion pressure.

Examination of the pelvis and groins

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:

  • There may be a rash of thrush, or a groin haematoma, or an external fixation device.
  • The posterior pelvis and sacrum should ideally be palpated for pitting oedema.

Examination of the lines

  • One should take notice of anything going into or coming out of the femoral vessels.
  • There may be a vascath, a PiCCO catheter or some sort of angiography sheath. These are important clues. Why did this patient get an angiogram? What is the PiCCO for?

The endoluminal repair of an aortic aneurysm typically leaves behind an angio sheath or at least a big hole. Enquire about anything which has recently been removed from the femoral vessels.

Examination of the genitals and rectum

  • A complete examination would call for the palpation of the testes, and a comment on their size. However, this may not be practical.
  • One should take note of any sort of waste management devices, eg. rectal tube, SPC or IDC.
  • One should definitely ask about performing a PR.
  • If one is forbidden from performing the PR, one should ask about the following features:
    • Anal sphincter tone
    • Size and quality of the prostate
    • Presence of melaena or hard stool

Once one is finished with the pelvis, one should cover it again, so that only the legs are sticking out.

Examination of the lower limbs

One should ask to remove TEDs and compression stockings.

  • One should observe whether the lower limbs are mottled, and whether they are of the same size (assymetrical swelling leads one to suspect lymphoedema or DVT)
  • One should palpate the larger muscles.
  • One should assess the temperature difference between the limbs, which could be important in the assessment of peripheral vascular disease, or of the embolic complications of -AAA repair.
  • Pitting oedema should be palpated.
  • Long bone injuries in a trauma patient may be obscured by casts and splints; if these are present, one should ask what lies beneath - compartment syndrome with rhabdomyolysis may be an important feature.
  • Test leg muscle tone
  • Look for calf tenderness

Feet and the Babinsky reflex

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.

Babinsky reflex

One should test the Babinsky bilaterally.

Clonus

One should attempt to assess clonus in both feet.

Power in the lower limbs

If one has ample time, one can conclude the examination by performing a brief neurological exam.

Power of the muscle groups may be tested in the following sequence:

  • Ankle dorsi and plantarflexion
  • Knee flexion and extension
  • Hip flexion, extension, adduction and abduction.

Sit the patient back up again.

  • Hand grip
  • Wrist dorsiflexion/palmarflexion
  • Elbow flexion/extension
  • Shoulder adduction / abduction

The measured observations

Ask to see the obs chart. If it is not allowed, ask for the following:

  • Trends of blood pressure and heart rate
  • Temperature
  • Drain output
  • Urine output

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

The laboratory investigations

One needs to show an interest in the following labs:

  • ABG
  • Routine bloods
  • Urinalysis
  • Sediment microscopy - casts and RBC fragments
  • Urinary albumin/creatinine ratio
  • Culture results
  • CK
  • inflammatory markers

Imaging and other investigations

One should always ask for the following:

  • ECG
  • CXR
  • Renal tract ultrasound

You sometimes want to see the following:

  • CSF analysis
  • CT or MRI results

 

Case presentation and discussion: when you have a good idea of what is going on

"Mr Bloggs' renal failure is likely caused by [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]"

"My approach to dialysis in this scenario would consist of the following strategies: [discuss modality, dose, anticoagulation, frequency]"

Case presentation and discussion: when you don't have a clue

"Mr Bloggs' renal failure is likely multifactorial; at this stage I am unable to commit to a single diagnosis."

"Contributing factors may include [list of potential contributing aetiologies]."

"I have identified clinical findings which support this hypothesis: namely, [insert list of findings]."

"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]"

"My approach to dialysis in this scenario would consist of the following strategies: [discuss modality, dose, anticoagulation, frequency]"

Number of previous hot cases in this topic: 3

2014, paper 2

Unspecified hospital in Sydney

  • 48-year-old man, day 7 ICU following repair of mycotic coronary artery aneurysms. Background of diabetes, and dialysis-dependent renal failure. Shocked, on adrenaline and noradrenaline infusions and VA ECMO. Clinical findings included fluid overload, AV fistula, poor circulation to the right leg, and oozing from the sternal wound.
  • Candidates were asked to assess with regard to the cause of the renal failure.
2014, Paper 1

Royal Brisbane and Women’s Hospital

  • 48-year-old man, day 7 ICU following repair of mycotic coronary artery aneurysms. Background of diabetes, and dialysis-dependent renal failure. Shocked, on adrenaline and noradrenaline infusions and VA ECMO. Clinical findings included fluid overload, AV fistula, poor circulation to the right leg, and oozing from the sternal wound.
  • Candidates were asked to assess with regard to the cause of the renal failure.
2007, Paper 2

Unspecified hospital

  • 60 year old male admitted with uraemia and sepsis. Discussion: Candidates asked to examine and determine a plan for his renal replacement therapy.