In this follow up to CritCases 13, Shock and Hypoxia in Blunt Chest Trauma, a collaboration between STARS Air Ambulance Service, Mike Betzner and EM Cases, Mike Misch guides us through the challenging management of bronchopleural fistula …

Written by Michael Misch. Edited by Anton Helman. January 2020.

Start with Part 1 of this case Crit Cases 13 – Shock and Hypoxia in Blunt Chest Trauma

A 26-year old male is involved in a high-speed, single vehicle MVC. He required extrication by paramedics who reported significant damage to the vehicle. Initial vitals on scene were T 37.0, HR 130 bpm, BP 90/40, RR 38, O2 Sat 78%, up to 88% with a non-rebreather. GCS is 12. A bolus of crystalloid is started and the patient is brought into your emergency department. You work in a regional centre with general and thoracic surgery. But you are not a trauma center, nearest trauma center is 50 mins by flight.

Primary survey reveals a patent airway without stridor or signs of blunt or penetrating injury. Patient is in a C-collar. There is vomitus on the patient’s face and chest. There is significant ecchymosis of the chest bilaterally and subcutaneous emphysema on the left. Abdomen is soft without ecchymosis.

You perform 2 finger thoracostomies in the 4th intercostal space. A gush of air is returned. You insert a 32 F chest tube. Chest X-Ray confirms chest tube placement – 2 on the left in good position; chest tube on the right position not ideal but is acceptable. You call your regional trauma team for transfer, but it is determined that the patient is “too sick” for transport at this time.

The patient then returns to DI to complete the pan-scan. Shortly after returning from the scanner, the radiologist calls you. CT shows no intra-abdominal or intracranial injury. There are multiple rib fractures with extensive pulmonary contusions bilaterally, more so on the left, with bilateral hemopneumothoraces. The radiologist tells you there’s still deviation of the mediastinum to the right. Looking back at the Chest X-Ray obtained post second chest tube insertion, you realize this also showed over-inflation of the left lung with shift of the mediastinum.

Repeat vitals: HR 110, systolic BP 80-90, Oxygen Sat 85%. You note that there is still continuous bubbling at the water seal, which again stops with clamping of the chest tube at the patient.

You call your thoracic surgeon on call who happens to be in hospital. He recommends a third chest tube on the left side as a temporizing measure as this patient will likely require an emergency thoracotomy to repair the fistula if his hemodynamics do not improve. He also suggests this patient may need ECMO. In the meantime, you place a third chest tube on the left side in the 5th intercostal space.  You call the transport team and tertiary center, but there is ongoing concern about the patient’s stability for transport. You call your anesthesiologist to help with managing the patient on the ventilator and in case the patient might need to go to the OR for a thoracotomy.


How can you optimize mechanical ventilation for this patient with a presumed bronchopleural fistula?

“Patient is too sick to fly right now. I would want to know the vent settings. Could you lower the volumes and increase the rate to reduce the air leak. This patient needs ECMO. I would consider ground transport with a doc/vent and accept sats of 85% for transport.”

-Arun Abbi MD FRCPA, Transport Physician STARS


“Tension physiology will worsen in rotary environments for sure due to lack of pressurization, and may worsen in fixed wing pressurized aircraft as well, due to inconsistent pressurization and or the inability to pressurize to the same level the patient is coming from for the entire flight.”

-Michael Betzner, Emergency Physician CHR


Positive pressure ventilation of patients with bronchopleural fistula poses significant challenges, as ventilations delivered to the lung pass directly to the pleural space causing loss of tidal volumes and atelectasis.

The goal of mechanical ventilation is to minimize flow across the fistula by keeping airway pressure below the critical opening pressure of the fistula.

  • Minimize PEEP
  • Short inspiratory time
  • Low tidal volumes
  • Ideally spontaneous breathing (likely not feasible in this case)
  • Permissive hypercapnia

Peak airway pressures over 30 cm H20 are associated with increased air leaks. Also, negative suction on chest tubes can perpetuate flow through the fistula and should be avoided.


Are there any other temporizing measures that can improve the patient’s ventilation to stabilize the patient enough for transport?

The patient requires significant ventilatory support of severe bilateral pulmonary contusions, but the large bronchopleural fistula requires lower airway pressures. When the ventilatory needs of the two lungs differ, treating them as single unit is detrimental. Differential lung ventilation is used to manage respiratory failure when there is marked difference in the pulmonary mechanics of the right and left lung due to a unilateral lung pathology, such as in severe pneumonia, massive pulmonary hemorrhage, and as in this case, a bronchopleural fistula

In this case, you need to isolate the right lung. Here are your options:

  1. Bronchial Blocker

While there are multiple brands of blockers available, all consist of a tube with an inflatable cuff that can be inserted through an endotracheal tube into the left or right bronchus. Occluding ventilation of the left lung will decrease flow across the bronchopleural fistula and allow independent ventilation of the right lung. They generally are inserted with bronchoscopic guidance, and while blind insertion is possible, you would probably want to avoid this in the case of trauma. You don’t know at what level the bronchial injury has occurred and blind insertion of the blocker could cause complete disruption of the bronchus. A primer on bronchial blocker insertion is available here:

Bronchial Blockers. Basics of Anesthesia, 2019.

2. Double Lumen Endotracheal Tube (DLTs)

  • DLTs have both a bronchial and tracheal lumen (image below). They are quite large and stiff, sometime making insertion difficult. An average size male would need a 41 F double lumen tube which is slightly larger than a size 10.0 ETT.
  • While there are both left and right sided DLT, the left DLT is more commonly used as the anatomy of the left bronchus is more predictable, allowing insertion blindly if necessary (again caution with blind insertion and converting a bronchopleural fistula to a complete bronchial disruption).

Left-sided double lumen endotracheal tube. Basics of Anesthesia, 2019.

3. Right Main Bronchus Intubation

  • Options 1 and 2 require equipment that is likely not in your ED. However, if your hospital has a thoracics service, anesthesia will likely have some expertise in both of these options. If these options are not available to you, then you can consider advancing the ETT into the right mainstem bronchus to facilitate ventilation of the right lung and minimizing airway pressures on the left side.

“The use of the blocker is possibly problematic in that you don’t know where the left airway injury has occurred. If it is at the take-off of the left mainstem, you can completely disrupt the bronchus. You ideally need to scope before inserting the blocker to locate the disruption. You can isolate the right lung with the single lumen tube, but this isn’t always a good solution as you may obstruct the right upper lobe bronchus, turning 3 lobes into 2.  The ideal is a double lumen tube, but again you need a bronchoscope to position. A guy with a potential C-spine injury like this patient has, is not someone I’d be thrilled re-intubating with a very large, stiff tube.”

-Saul Pytka MD, FRCPC, Associate Professor of Anesthesiology (Clinical), University of Calgary


“I think it is fair to consider the EZ blocker as well as moving that tube mainstem if you had to (obviously mainstem using a bronchoscope would be way smarter than blindly)…. Hail Mary because ECMO is a long time away.”

-Heather Hurdle MD FRCPC, Anesthesiology Foothills Medical Centre, Transport Physician STARS


Anesthesia places a bronchial blocker on the left side. The patient’s blood pressure improves to 100/60, HR comes down to 100, Oxygen saturation 85%. He’s no longer in tension, there is no longer an air leak on the left side. You re-initiate transport to the trauma centre, given that the patient seems to have temporarily stabilized. Given that bronchial blockers can become easily dislodged during movement of the patient, anesthesia exchanges the bronchial blocker with a 41 F DLT to facilitate transfer.


“The reasoning to change to a L double lumen tube is correct. The blocker can easily be displaced with movement, particularly into and out of aircraft/ambulance etc. Even head up or down moves the carina up or down relative to the face (fixed point) and can dislodge the blocker (By as much as 4 cm).”

-Saul Pytka MD, FRCPC, Associate Professor of Anesthesiology (Clinical), University of Calgary


How can you optimize one-lung ventilation?

One-lung ventilation poses some unique challenges. When you selectively ventilate only one lung, there is a large shunt on the non-ventilated lung. Pulmonary vasoconstriction that occurs on the left side in response to hypoxia (hypoxic pulmonary vasoconstriction) reduces left lung perfusion from 50% of cardiac output to about 30% in an attempt to correct the resulting V/Q mismatch. Positioning the patient with the ventilated lung down (in this case, right semi-lateral or right lateral decubitus) also helps to redirect pulmonary blood flow to the ventilated lung. However, despite this, there is still large volume of blood perfusing the left lung that is not being ventilated (ie: large shunt), perpetuating hypoxia.

Optimal one-lung ventilation would include:

  • Lower tidal volume: 4 to 6 mL/kg
  • Adjust Respiratory Rate to target patient’s normal PaC02 at EtCO2
  • PEEP 5-10 cm H20 (0 to 5 cm H20 if COPD)
  • Plateau pressure < 30 cm H20
  • Minimal FiO2 to maintain Sp02 > 90%

These goals assume that the one lung you are ventilating is healthy – however, we are relying on the single ventilation of a severely injured lung. As such, we will likely require high FiO2 (as demonstrated by the fact that the patient has needed 100% Fi02 so far. Also, permissive hypercapnia can be advantageous in one-lung ventilation as it potentiates hypoxic pulmonary vasoconstriction, which helps to reduce shunt and improve perfusion of the ventilated lung.


The transport paramedic, RN and physician arrives. Transport is 50 minutes by plane. With the patient ventilated on the right lung only the vitals are:

  • Sat 85% on 100%FiO2, PEEP10 cm H20
  • HR 100 bpm, BP 110/70 mmHg
  • EtCO2 45, Vent rate 40, Vt ~280 cc, Plateau Pressure 30 cm H20
  • pH 7.19 / PaCO2 68 / PaO2 58 / HCO3 24 / Lac 1.6


Thoughts on his blood gas prior to transfer of this patient with bronchopleural fistula?

“Hypercarbia on one lung wouldn’t bother me…losing the lung isolation during any type of transport would be my biggest worry if the patient is otherwise stable.”

-Heather Hurdle MD FRCPC, Anesthesiology Foothills Medical Centre, Transport Physician STARS

You are appropriately targeting low tidal volumes with a PEEP 10. The patient is quite hypercapneic, which can be tolerated in this circumstance and again can help to reduce shunt during one-lung ventilation. Despite 100% Fi02 and a PEEP at upper limit of your target, the patient remains hypoxemic. Reassuringly, the patient’s lactate is 1.6, suggesting the patient is tolerating this.


You decide you have optimized the patient the best you can and send the patient for transport. The patient will be kept on the ventilator during flight. Unfortunately, you don’t have a bronchoscopy to take with you. While en-route, the patient has a progressive desaturation from 88% down to 73% over 10 minutes.

As the transport doc, what is your approach to the patient who is desatting on a ventilator?

As in any crashing intubated patient, you can use the DOPES mnemonic:

  • Displacement of the tube
    • Check tube has not been displaced – ideally you would have a bronchoscope to ensure position of the DLT in the left bronchus
  • Oxygen
    • Check O2 source
  • Pneumothorax
    • Is there an air leak again? Any signs of tension?
  • Equipment
    • Check your connections on the ventilator as well at the water seal
  • Stacking of breaths
    • Consider in asthmatics especially, disconnect the patient from the vent, decompress the chest by slowly deflating the patient with a gentle squeeze on both sides of the chest, and then manually bag the patient (Ideally with a PEEP valve)

Some authors would suggest that an “R” should be added DOPES to make DOPERS to account for chest wall rigidity, secondary to fentanyl (an uncommon but deadly complication of common medication used in ventilated patients). If this were the case, the antidote would be naloxone.


You go through the DOPERS mnemonic, including taking the patient off the ventilator and manually bagging the patient without improvement.


What else could be going on in this patient with bronchopleural fistula who is desatting?

While this could certainly just be progressive decline secondary to his severe bilateral pulmonary contusions, you created a large shunt when deciding to perform one-lung ventilation, which can worsen hypoxemia when relying on a severely injured lung. There a few steps to consider:

  • Increase Fi02
    • We are already maxed out here
  • Provide a fluid bolus
    • May optimize cardiac output and pulmonary perfusion
  • A best PEEP trial on the ventilated lung
    • Ideal PEEP is usually 5-10 cm H20, but you can try to adjust this to see if saturations improve
    • Too little PEEP causes atelectasis of the dependent ventilated lung, worsening shunt and hypoxia
    • Too much PEEP increases pulmonary vascular resistance on the dependent lung and redirects pulmonary blood flow to the non-ventilated lung
  • Add 5-10 cm H20 of CPAP to the non-ventilated lung
    • This can decrease the shunt fraction by providing oxygen to the circulating blood in the non-ventilated lung. This will have to be done carefully given the concern regarding increasing flow through the BPF


“One strategy during one lung ventilation is to actually leave some oxygen in the “collapsed”, non-ventilated lung (ie left lung) so that the shunted blood can pick up some O2. What I have done in the past was to slightly inflate the non-ventilated lung, then clamp that side shut, leaving residual oxygen on that side. As it absorbs, the O2 sat will drop, and you simply repeat the process. Another maneuver is to run low pressure O2 into that side so you get diffusion of O2 into the collapsed lung, but that can lead to barotrauma if you aren’t careful.”

-Saul Pytka MD, FRCPC, Associate Professor of Anesthesiology (Clinical), University of Calgary


You place a BVM with a PEEP valve set to 10 cm H20 on the left bronchial lumen, while continuing to ventilate the right lung with the ventilator on the tracheal lumen. O2 sat increases to 90-92 % and the patient remains stable for the rest of transport.


“This is an excellent maneuver in a supine one lung ventilated patient that can be used when you need to stay on one lung but your hypoxic vasoconstriction isn’t working well enough(to overcome shunt from not ventilating the left lung).”

-Heather Hurdle MD FRCPC, Anesthesiology Foothills Medical Centre, Transport Physician STARS


Case Resolution

The patient arrives at the tertiary hospital and admitted to the ICU, a left sided bronchopleural fistula was subsequently identified on bronchoscopy and was repaired endoscopically. He is eventually transferred to the trauma ward and recovers neurologically intact.


Take-Home Points for management of bronchopleural fistula

  1. Continuous air leaks post chest tube insertion suggests either circuit malfunction or massive air leak from bronchopleural fistula or severe lung laceration and require immediate intervention
  2. Bronchopleural fistulas often require multiple chest tubes. Avoiding suction on chest tubes, permissive hypercapnia while minimizing tidal volumes and PEEP can minimize flow through BPF and aide in mechanical ventilation. If this is not sufficient, insertion of bronchial blocker, DLT may be necessary
  3. One-lung ventilation is a technique to manage respiratory failure in the context of unilateral lung pathology such as bronchopleural fistula, severe pneumonia or massive pulmonary hemorrhage. This requires expertise in ventilator management with titration of PEEP, FiO2, and occasionally ventilation of the downed lung to overcome the resultant shunt physiology.


References for management of bronchopleural fistula

  1. Cheatham ML, Promes JT. Independent lung ventilation in the management of traumatic bronchopleural fistula. Am Surg. 2006;72(6):530-3.
  2. Karzai W, Schwarzkopf K. Hypoxemia during one-lung ventilation: prediction, prevention, and treatment. Anesthesiology. 2009;110(6):1402-11.
  3. Lois M, Noppen M. Bronchopleural fistulas: an overview of the problem with special focus on endoscopic management. Chest. 2005;128(6):3955-65.
  4. Martin M, Slinger P. One Lung Ventilation: General Principles. In:Uptodate, Hine, R(Ed), UpToDate, Waltham, MA, 2019.
  5. Shekar K, Foot C, Fraser J, Ziegenfuss M, Hopkins P, Windsor M. Bronchopleural fistula: an update for intensivists. J Crit Care. 2010;25(1):47-55.