CASE REPORT - Tension pneumothorax caused by ventilating rigid bronchoscopy for removal of foreign body

Safdar Hussain, MCPS*, Riaz Ahmed Khan, MCPS, FCPS**,
Muhammad Iqbal, FCPS***

*Consultant, **Associate Professor and Head, ***Assistant Professor

Department of Anaesthesia, Pain and Intensive Care, Rehman Medical Institute, Hayatabad, Peshawar (Pakistan).

Correspondence: Col (R) Riaz Ahmed Khan, Head, Department of Anaesthesia, Pain and Intensive Care, Rehman Medical Institute, Hayatabad, Peshawar (Pakistan); e-mail: riaz_kmc75@yahoo.com

ABSTRACT

Tension pneumothorax during ventilating bronchoscopy for foreign body removal is a rare but life threatening complication, which if not promptly diagnosed and treated can prove fatal. We present a case of tension pneumothorax, due to a laceration in the right main bronchus caused by bronchoscope, in a one year old child, who underwent bronchoscopy for removal of foreign body (bead). The child was successfully treated and managed by immediate insertion of 14 gauge IV cannula in the pleural cavity followed by chest tube insertion. The laceration was subsequently repaired and foreign body removed by thoracotomy.

Key Words: Ventilating bronchoscopy; Tension pneumothorax

Citation: Hussain S, Khan RA, Iqbal M. Tension pneumothorax caused by ventilating rigid bronchoscopy for removal of foreign body. Anaesth Pain & Intensive Care 2011;15(1):57-59.

INTRODUCTION
Ventilating rigid bronchoscopy is commonly used for removing foreign bodies from the tracheo-bronchial tree. Foreign body impaction in the airway is a common cause of death in children1. Haemorrhage, post-procedure laryngeal oedema and tracheo-bronchial lacerations can occur during ventilating bronchoscopy2. Tension pneumothorax is the most serious consequence of rigid bronchoscopy3,4. This occurs when a one way valve mechanism develops because of tracheo-bronchial instrumentation leading to a rent allowing the air to enter the pleural cavity during positive pressure ventilation but not allowing it to leave during expiratory phase. As the air builds up in the pleural space, ipsilateral lung is compressed followed by mediastinal shift and compression of contralateral lung and intrathoracic vasculature. This leads to severe hypoxemia and cardiovascular compromise. Tension pneumothorax should be suspected in mechanically ventilated patients who suddenly decompensate5. Early diagnosis and prompt management are essential for an optimum outcome. Therefore, this complication must be kept in mind and should be ruled out whenever ventilation is impaired and there is sudden cardiovascular compromise during anaesthetic management for ventilating bronchoscopy 6.

CASE REPORT
A one year old female child, weighing 11 kg, was admitted through ER department with a one day history of foreign body inhalation followed by severe bouts of cough and dyspnea. Pre-operative examination showed a healthy female child with symmetrical chest expansion, reduced air entry on the right side and SpO2 of 100%. She was not dyspneic and was normothermic at the time of inspection, without any other medical problem. Pre-op chest x-ray showed a foreign body in the right main bronchus (Fig1).

Fig 1: Pre-operative chest x-ray showing a foreign body in the right main bronchus (arrows)
Without any premedication, anaesthesia was induced intravenously with inj. propofol 2mg/kg IV and supplemented by sevoflurane 3-4 MAC with 100% oxygen. Inj. atropine 0.2mg was given IV and muscle relaxation was obtained with a small 5-10mg dose of suxamethonium. Rigid bronchoscope was inserted by otolaryngologist and attempts were made to get hold the foreign body with the forceps. 30 minutes after starting the procedure patient’s SpO2 started falling down to 40%, with cyanosis. Heart rate went upto 200 beats/minute. Child’s abdomen was distended and on auscultation no breath sounds could be heard over the right hemithorax. The surgeon was asked to stop the procedure and an uncuffed endotracheal tube (size 4.0 ID Endosoft) was put in the trachea under direct laryngoscopy and the patient was manually ventilated with 100% oxygen. High airway resistance was encountered with only a slight improvement in SpO2, upto 80%. Still no breath sounds were audible on the right side on auscultation. Immediate portable chest x-ray was requested, which showed a massive right sided pneumothorax with depression of right hemidiaphragm and shifting of trachea and mediastinum to the left with compression of the left lung (Fig 2).

Fig 2: Chest x-ray showing a massive right sided pneumothorax with depression of right hemidiaphragm and shifting of trachea and mediastinum to the left with compression of the left lung
A 14 gauge IV cannula was immediately inserted in the 2nd intercostal space in the midclavicular line. A gush of air leaked out through the cannula and ventilation became easier. Within a few minutes SpO2 rose to 100%. Subsequently, another size-14 cannula was passed in the midaxillary line in the 5th intercostal space and connected by an IV infusion set to a temporary under-water seal after removing the 1st cannula. Repeat chest x-ray showed marked improvement with re-expansion of the right lung and mediastinal shift back to its position. (Fig 3)

Fig 3: Post-op chest x-ray showing re-expansion of the right lung
A chest tube was placed in the right pleural cavity by the thoracic surgeon followed after a day by right thoracotomy which showed a small 0.7mm rent in the right main bronchus through which foreign body was removed and the rent was sutured. Child showed uneventful recovery and was discharged after a few days.

DISCUSSION
Ventilating rigid bronchoscopy has inherent risks and complications such as bleeding, laryngeal trauma, laryngeal oedema, laryngospasm, bronchospasm, infection, hypoxemia, tracheobronchial lacerations and tears leading to pneumothorax2, pneumomediastinum and surgical emphysema of the chest wall and neck.

Tension pneumothorax is a rare but life threatening complication3,4. Rothmana and Boeckman7 reported that the probability of developing pneumothorax during rigid bronchoscopy for the removal of foreign body is approximately 1 in 100 cases. It usually results from direct trauma to tracheobroncaheal tree. Therefore, the possibility of pneumothorax should always be kept in mind when ventilation worsens during ventilating bronchoscopy8. An early diagnosis of pneumothorax during anaesthesia, however, is not so easy as the symptoms may be masked by anaesthesia6. Full monitoring is essential to alert the anesthesiologist of a worsening situation. Tension pneumothorax during surgery may manifest itself by a fall in oxygen saturation, a rapid increase in airway pressure, hypotension and tachycardia9. In our case, bronchial laceration caused by rigid bronchoscope was responsible for tension pneumothorax. Immediate intervention to release the built up pressure in the pleural cavity can be achieved by a large bore IV cannula and is life saving, to be followed by chest tube insertion. Vigilance is the price of safety.

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