Traumatic Diaphragmatic Hernia

• Resuscitation and trauma management
• Emergency thoracic and abdominal surgery
• Airway management with aspiration risk
• Complex respiratory mechanics
• Potentially catastrophic haemodynamic compromise
• Double lumen tubes
• Postoperative pain management

• High speed road traffic collisions
• Penetrating thoracic or abdominal trauma
• Falls from significant height
• Crush injuries

Usually they're asking this to see if you can appreciate the difference between acute and delayed presentations of this condition.

Acute

• Polytrauma or major trauma patient
• Respiratory distress
• Chest and abdominal pain
• Haemodynamic instability
• Hypoxia

Delayed

• Reduced exercise tolerance
• Recurrent aspiration or chest infections
• Dyspnoea
• Bowel obstruction
• Acute abdomen
• Sepsis from strangulated bowel

• Sudden increase in transdiaphragmatic pressure gradient
• Radial tear of diaphragm
• Progressive enlargement over time (hence the delayed presentation)
• Negative intrathoracic pressure gradually pulls abdominal organs into chest
• Usually it's stomach, colon or small bowel
• It's more common on the left because the liver provides some protection to the right side

Although using your liver as a crumple zone to protect your diaphragm seems slightly counterproductive.

• Hypoxia
• V/Q mismatch - enormous shunt in area of compressed lung
• Restrictive respiratory deficit
• Reduced FRC

Standard stuff you'd expect from the lung having an unwanted gastric room mate.

• Reduced venous return
• Reduced cardiac output
• Mediastinal shift
• Direct cardiac compression

In severe cases the haemodynamic compromise can mimic that of a tension pneumothorax.

• Vomiting
• Bowel obstruction
• Gastric volvulus
• Strangulation

Clearly this patient is going to be high risk for aspiration.

This is an acutely unwell patient presenting for emergency surgery, with:

• Respiratory and haemodynamic compromise
• High risk of aspiration
• Potential bowel obstruction
• Other possibly life threatening injuries

On top of a full anaesthetic history and examination, you want to pay particular attention to:

• Other injuries including c-spine
• Oxygen requirement
• Evidence of respiratory compromise
• Evidence of haemodynamic compromise
• Exercise tolerance
• Comorbidities

Is there anything else that's going to make this even trickier?

• Bloods - bleeding, infection
• CXR - stomach in chest, mediastinal shift, lung volume reduction
• CT - identification of abdominal organs in thorax, evidence of ischaemia and obstruction
• ECG - and echocardiogram if significant haemodynamic compromise

• Large bore IV access and fluid resuscitation
• Analgesia
• Antiemetics
• NG tube - to empty stomach and improve respiratory mechanics
• Crossmatch and blood if bleeding

• Monitoring - full AoA monitoring, arterial line, consider CVC if unstable
• Positioning and preoxygenation - head up, consider HFNO
• Rapid sequence induction and endotracheal intubation
• Double lumen tube or bronchial blocker if one lung ventilation required*

*Not all repairs require lung isolation, it will depend on the surgical approach (laparotomy, thoracotomy, thoracoscopy).

The examiner may then dive off down the rabbit hole of double lumen tubes, which we've covered in this post.

• Loss of sympathetic tone
• Reduced preload due to intrathoracic compression and hypovolaemia*
• Hypovolaemia due to vomiting, poor intake and bleeding

*Made worse by positive pressure ventilation.

As always, gas or TIVA depending on your institution and what is safer in your hands.

• Expect high airway pressures and reduced lung compliance
• Oxygenation may be difficult if significant shunt
• Lung protective ventilation is usually a good idea
• Catheter to monitor urine output
• Close temperature and blood glucose control
• Replacement of blood products where necessary

It's a good idea to explicitly mention that you'd avoid excessive airway pressures and PEEP in a patient with raised intrathoracic pressure.

This could be multifactorial, and you need to address each in turn:

• Reduced venous return
• Tension physiology
• Bleeding
• Septic shower
• Vagal stimulation from pleura or peritoneum - especially if suddenly bradycardic

The key here is this is most likely due to shunt, so just increasing the FiO2 probably isn't going to achieve a whole lot.

• Increase FiO2
• Call for skilled assistance
• Check the tube position
• PEEP to dependent lung
• Consider CPAP to non-dependent lung

• Viscera are returned to the abdominal cavity
• Abdominal pressure increases
• Reduced diaphragmatic excursion
• Reduced compliance
• Increased airway pressure

You first need to decide whether they're safe to extubate.

• Ongoing shunt and high oxygen requirement
• Ongoing respiratory compromise from diaphragmatic splinting
• Cardiovascular instability

There may be many reasons to keep them asleep on intensive care for a while.

If you do decide to extubate, aspirate the NG tube and do it the same way you would for an emergency bowel obstruction laparotomy - wide awake.

• Destination is usually HDU or ICU after major emergency thoracic surgery - may require ongoing ventilatory support*
• Analgesia - multimodal, opioid sparing, epidural may be appropriate
• Antiemetics - multimodal and generous

*Need to watch out for re-expansion pulmonary oedema as well as postoperative ileus and sepsis from strangulated bowel.

• Thoracic epidural
• Paravertebral block
• Erector spinae plane block
• Serratus anterior plane block
• Intercostal block
• Interpleural block