2.4 Tamponade Flashcards
You are asked to review a 65-year-old man on the cardiac intensive care unit who underwent coronary
artery bypass surgery earlier in the day.
a) Which clinical signs suggest the development of acute cardiac tamponade? (40%)
> > Classically, Beck’s triad:
hypotension,
raised jugular venous pressure,
muffled heart sounds.
> > Shock
(hypotension, tachycardia, clammy, cool peripheries, poor capillary refill, reduced cerebration, cardiac arrest) resistant to fluids and inotropes.
> > Pericardial rub.
> > Pulsus paradoxus:
abnormally large reduction in
systolic pressure during inspiration.*
> > Kussmaul’s sign: rise/lack of
fall of JVP with inspiration.**
- During spontaneous inspiration, the full right heart encroaches on the left and blood pools in the pulmonary vasculature, both of which reduce left
heart filling, thus causing a decrease in systolic pressure. In tamponade, the effect is exacerbated and the difference in pressure between the right and
left heart is lost. Positive pressure ventilation results in a reversal of timings.
**Due to failure of the constricted right heart to accommodate the increase
in venous return that occurs with the drop in intrathoracic pressure that
accompanies spontaneous inspiration.
b) List the investigations and their associated derangements that could confirm the diagnosis of acute cardiac tamponade. (15%)
Transoesophageal or transthoracic echo:
> > Pericardial separation of more than 1 cm
(however, pericardial collections may be atypical in appearance following cardiac surgery yet still cause
significant haemodynamic compromise).
> > Sequentially, with worsening tamponade,
right atrial free wall collapse in systole,
right ventricular free wall collapse in diastole,
left atrial free wall collapse in systole.
> > Exaggerated respiratory variation in
trans-tricuspid and trans-mitral flow.
> > Left shift of the interventricular septum.
> > Inferior vena cava dilatation
without respiratory variation in size.
> > ‘Swinging heart.’
> > Chest radiograph: enlarged cardiac silhouette (‘flask shaped’).
ECG: small complexes, electrical alternans.*
* Varying waveform size due to movement of the heart within the pericardial
sac from beat-to-beat.
Other diagnostic investigations are unlikely to be useful given the time frame of acute tamponade:
> > Ultrasound-guided pericardiocentesis:
aspiration of free-flowing blood –
relatively contraindicated in patients with ongoing anticoagulation.
Neither cardiac catheter studies
(equalisation of chamber pressures)
nor CT scan
(presence of blood or clot in pericardial space)
should be considered in
an acute, decompensated setting.
c) What is the management of acute cardiac tamponade in this patient? (45%)
> > Cardiac tamponade following cardiac surgery
is likely to be due to failed haemostasis and,
therefore, rapidly progressive
with risk of cardiac arrest and high mortality.
I would plan for decompressive sternotomy on
the intensive care unit as no time permitted
for transfer to the operating theatre.
Opening the sternum usually reverses the life-threatening haemodynamic compromise.
I would follow an ABC approach, assessing
and managing the patient simultaneously.
> > Fast-bleep team and call for resternotomy trolley:
• The surgical team should be ready before induction.
• Anaesthetic and ODP support
should be requested but may need to
proceed without their assistance
if the patient is rapidly deteriorating.
• Perfusionist to be contacted –
may need to go back on bypass.
• Major haemorrhage protocol to be activated.
Patient management:
- A: 100% oxygen reduces cardiac workload.
- B: Intubate (if not still intubated from earlier surgery). Positive pressure ventilation will have deleterious effect on cardiac filling, and PEEP and high airway pressures should be avoided.
Do not induce until surgeons are poised ready to go. Maintain oxygenation with minimal ventilation.
• C: Large-bore intravenous access should be secured (if not already present from theatre).
Intravenous filling to attempt to maximise
effective venous return.
Use of vasopressor if necessary.
• D: If the patient is sufficiently stable for induction drugs to be used, consider use of opiates, ketamine, benzodiazepines.
Avoid causing myocardial depression. If the patient is periarrest, it may be inappropriate to use any induction drugs.
• H: Massive haemorrhage protocol should be activated.
However, tamponade is not always associated with large blood loss.
The patient may already be coagulopathic from recent bypass surgery or may develop coagulopathy with blood loss.
Haemoglobin and coagulation should be monitored with near patient testing,
with blood administration,
reversal of heparin and
administration of other clotting
products as indicated.
Alternatively, management of
anticoagulation to
go back on bypass may be needed.
a) What clinical features might
suggest the development of
cardiac tamponade? (9 marks)
Symptoms:
» Shortness of breath.
> > Sharp chest pain radiating to the shoulder, neck, back, abdomen; may be pleuritic.
> > Anxiety, restlessness, dizziness, drowsiness.
Monitoring:
> > Increasing CVP.
> > Progressive hypotension or increasing dose of vasopressor required to maintain blood pressure.
> > Reduction or sudden loss of chest drain output.
> > Equalisation of atrial and LVEDP if in pulmonary artery catheter in situ.
> > Oliguria – although rapid timeframe may mean that this is not observed before the patient is periarrest.
