List the findings, advantages and disadvantages of the following methods of assessment in a patient with right ventricular failure secondary to pulmonary hypertension: 
 
a)    Clinical bedside Assessment.                           (30% marks) 
 
b)    Transthoracic Echo.                                         (40% marks) 
 
c)    Pulmonary Artery Catheter.                             (30% marks) 

[Click here to toggle visibility of the answers]

College answer

Findings:

  • Raised JVP with prominent A wave, pulsatile liver. 
  • Loud P2, RV/parasternal heave
  • TR murmur
  • Bilateral Peripheral edema
  • Hypotension if severe 

Advantages

  • Quick
  • Simple
  • Cheap
  • Non-invasive

Disadvantages

  • Poor reproducibility
  • Often difficult in ICU – immobility of patient, equipment, dressings etc
  • May be impaired by patient habitus
  • Non-quantitative
  • Continuous monitoring impractical

Transthoracic Echo                              

  Clinical Assessment

Findings 

  • ECHO: TR, long axis cavity size, short axis septal kinetics, apex loses triangular shape, 
  • RV size compared to LV size, 
  • loss of inspiratory collapse of IVC, dilation of PA
  • RVSP > 25 for acute 
  • TAPSE <16mm

Advantages

  • Non -invasive
  • Qualitative and quantitative
  • Can give other information relevant to clinical state
  • Record and retrieve results

Disadvantages

  • Expertise required
  • Expensive equipment
  • Inter operator variability
  • Unable to perform continuous monitoring
  • Often difficult in ICU – immobility of patient, equipment, dressings etc
  • May be impaired by patient habitus

Pulmonary Artery Catheter                             

 Findings

  • Right heart failure: high CVP, low CI, high PVR
  • Elevated pulmonary artery pressures (PAPm >25mmHg)

 Advantages

  • Continuous monitoring 
  • Gold standard for pulmonary hypertension measurement
  • Quantitative measurement
  • No inter operator variability
  • Can give other information relevant to clinical state
  • Therapeutic uses – iv access, pacing
  • Record and retrieve results

 Disadvantages

  • Invasive
  • Risk of serious complications – infection, bleeding, pneumothorax, vessel rupture 
  • Drift of measurements
  • Complex, now unfamiliar in many units
  • Time limited – should not be left in for > 72 hours

Discussion

Like virtually every other question which asks people to discuss and compare the advantages and disadvantages of something, this one would benefit from a tabulated answer in point-form, as this is much easier for the examiner to mark. The worst possible thing one could do is try to answer this in a block of flowing prose. 

Thus:

Diagnostic Strategies in Right Heart Failure
Modality and findings Advantages Disadvantages

Clinical examination:

  • Raised JVP
  • Pulsatile liver. 
  • Loud P2
  • RV heave
  • TR murmur
  • Oedema 

(for more detail, see above)

  • Quick
  • Simple
  • Cheap
  • Non-invasive
  • Good specificity
  • Poor sensitivity
  • Poor reproducibility
  • Non-quantitative
  • Made complex by ICU environment
  • Difficult in cardiac surgery/open chest

Transthoracic echo

  • TR
  • Chamber size
  • Septal kinetics
  • Apex shape 
  • IVC dynamic collapse
  • Dilation of PA
  • RVSP > 25 for acute 
  • TAPSE <16mm
  • Non -invasive
  • Qualitative and quantitative
  • Can give other information relevant to clinical state
  • Record and retrieve results
  • Serial examinations possible
  • "Operator-dependent" accuracy
  • Requires an ultrasound machine
  • Unable to perform continuous monitoring
  • Impaired by ICU environment: position, drains, dressings

PA catheter

  • High CVP
  • Low cardac output
  • High PA pressure
  • High PVR
  • Gold standard for right heart assessment
  • Quantitative measurement
  • No inter-operator variability
  • Can give other information relevant to clinical state
  • Therapeutic uses – IV access, pacing
  • Record and retrieve results
  • Invasive
  • Risk of serious complications 
  • Measurement subject to assumptions and errors (particularly with TR)
  • Drift of measurements
  • Complex, now unfamiliar in many units
  • Time limited – should not be left in for > 72 hours

References