Airway Strategies in Nail Gun Injuries to the Mouth
Airway Strategies in Nail Gun Injuries to the Mouth
The airway considerations for accommodating the surgical requirement for lung separation and cardiopulmonary bypass in a patient with iatrogenically limited mouth opening are challenging. Our patient, who remained cooperative and haemodynamically stable, had a three-inch nail pinning his mouth shut, preventing conventional intubation via the orotracheal route. The potential for rapid haemodynamic deterioration due to the intrathoracic penetrating injury required urgent surgical exploration. The uncertainty in the location of the intrathoracic nails meant the exact nature of the surgical repair was not defined and provision for lung separation needed to be planned for. In this case, the chest X-ray failed to allow an adequate appreciation of the nail within the thorax. This occurred because the nail was imaged in short axis resulting in its appearance as a dot, which rendered it difficult to see. There was also a loss of the characteristic nail shape, which would have facilitated detection. A lateral chest X-ray would have been useful in this scenario but this, unfortunately, had not been ordered. Although transthoracic echocardiography suggested the nail had penetrated the right ventricle, the exact location of the nail was not visualized.
The decision between performing more advanced imaging such as computed tomography or proceeding straight to the theatre has been historically biased towards the latter by the threat of patient deterioration during the workup process. Multidetector computed tomography can generate high-resolution multiplanar and volumetric images that allow rapid localization of bleeding and assessment of intrathoracic structures and has been shown to improve the outcome of patients with penetrating cardiac injuries.
The standard approaches to achieve lung isolation for penetrating intrathoracic trauma are well described and include: selective single-lumen endobronchial tubes, double-lumen tubes (DLTs), and endotracheal tubes with bronchial blockers. The requirement for heparin to enable the safe conduct of cardiopulmonary bypass necessitates selecting a minimally traumatic airway technique and one where bleeding can be controlled should it occur. The use of the Fogarty® embolectomy or bladder catheter as a bronchial blocker is mainly of historical interest and these devices have no role in lung separation strategies in the context of modern thoracic anaesthesia. The minimum safe tube length for endobronchial intubation via the nasal route is 40cm. Single-lumen endobronchial tubes compatible with nasal intubation measuring 45 and 47cm in length are commercially available for both right- and left-sided endobronchial intubation (for example RĂ¼schâ„¢, Teleflex Medical), however double-lumen tubes cannot be inserted nasally, or used in patients with abnormal upper or lower airway anatomy, or fixed and/or limited mouth opening. A double-lumen tube was therefore not considered suitable for lung separation in this case.
The Univent™ bronchial blocker is a single-lumen endotracheal tube with an enclosed bronchial blocker. Whilst nasotracheal intubation and lung separation using a Univent™ tube has been previously reported, the large outer diameter makes nasal intubation difficult and traumatic, particularly in small patients, and its use in this setting is not advocated. As described in this case, when lung separation is critical and the orotracheal route is unsuccessful or not possible, we advocate nasotracheal intubation using a standard nasal endotracheal tube and deploying an independent bronchial blocker such as the wire-guided Arndt endobronchial blocker, Cohen™ endobronchial blocker or Fuji™ endobronchial blocker. The Arndt® blocker for nasotracheal intubation and lung isolation has been reported but not in the context of penetrating chest trauma. A common problem for the thoracic anaesthetist is determining bronchoscope-endotracheal tube-blocker compatibility; therefore, a list of compatible endotracheal tubes, bronchoscopes and bronchial blockers is presented in Table 1.
Importantly, when there is a need for rapid lung isolation where conventional orotracheal or nasal intubation is not possible, a surgical tracheostomy can be performed under direct vision, and with minimal haemodynamic disturbance under local anaesthetic. Double-lumen tubes and endobronchial blockers can be inserted via the tracheostomy to achieve lung separation, in addition to commercially available lung isolation tracheostomy tubes (Tracheopartâ„¢). An algorithm for emergency lung separation when orotracheal airway instrumentation is not possible is presented in Figure 4.
(Enlarge Image)
Figure 4.
An algorithm for emergency lung separation when orotracheal airway management is not possible. DLT, double-lumen tube; ETT, endotracheal tube.
Discussion
The airway considerations for accommodating the surgical requirement for lung separation and cardiopulmonary bypass in a patient with iatrogenically limited mouth opening are challenging. Our patient, who remained cooperative and haemodynamically stable, had a three-inch nail pinning his mouth shut, preventing conventional intubation via the orotracheal route. The potential for rapid haemodynamic deterioration due to the intrathoracic penetrating injury required urgent surgical exploration. The uncertainty in the location of the intrathoracic nails meant the exact nature of the surgical repair was not defined and provision for lung separation needed to be planned for. In this case, the chest X-ray failed to allow an adequate appreciation of the nail within the thorax. This occurred because the nail was imaged in short axis resulting in its appearance as a dot, which rendered it difficult to see. There was also a loss of the characteristic nail shape, which would have facilitated detection. A lateral chest X-ray would have been useful in this scenario but this, unfortunately, had not been ordered. Although transthoracic echocardiography suggested the nail had penetrated the right ventricle, the exact location of the nail was not visualized.
The decision between performing more advanced imaging such as computed tomography or proceeding straight to the theatre has been historically biased towards the latter by the threat of patient deterioration during the workup process. Multidetector computed tomography can generate high-resolution multiplanar and volumetric images that allow rapid localization of bleeding and assessment of intrathoracic structures and has been shown to improve the outcome of patients with penetrating cardiac injuries.
The standard approaches to achieve lung isolation for penetrating intrathoracic trauma are well described and include: selective single-lumen endobronchial tubes, double-lumen tubes (DLTs), and endotracheal tubes with bronchial blockers. The requirement for heparin to enable the safe conduct of cardiopulmonary bypass necessitates selecting a minimally traumatic airway technique and one where bleeding can be controlled should it occur. The use of the Fogarty® embolectomy or bladder catheter as a bronchial blocker is mainly of historical interest and these devices have no role in lung separation strategies in the context of modern thoracic anaesthesia. The minimum safe tube length for endobronchial intubation via the nasal route is 40cm. Single-lumen endobronchial tubes compatible with nasal intubation measuring 45 and 47cm in length are commercially available for both right- and left-sided endobronchial intubation (for example RĂ¼schâ„¢, Teleflex Medical), however double-lumen tubes cannot be inserted nasally, or used in patients with abnormal upper or lower airway anatomy, or fixed and/or limited mouth opening. A double-lumen tube was therefore not considered suitable for lung separation in this case.
The Univent™ bronchial blocker is a single-lumen endotracheal tube with an enclosed bronchial blocker. Whilst nasotracheal intubation and lung separation using a Univent™ tube has been previously reported, the large outer diameter makes nasal intubation difficult and traumatic, particularly in small patients, and its use in this setting is not advocated. As described in this case, when lung separation is critical and the orotracheal route is unsuccessful or not possible, we advocate nasotracheal intubation using a standard nasal endotracheal tube and deploying an independent bronchial blocker such as the wire-guided Arndt endobronchial blocker, Cohen™ endobronchial blocker or Fuji™ endobronchial blocker. The Arndt® blocker for nasotracheal intubation and lung isolation has been reported but not in the context of penetrating chest trauma. A common problem for the thoracic anaesthetist is determining bronchoscope-endotracheal tube-blocker compatibility; therefore, a list of compatible endotracheal tubes, bronchoscopes and bronchial blockers is presented in Table 1.
Importantly, when there is a need for rapid lung isolation where conventional orotracheal or nasal intubation is not possible, a surgical tracheostomy can be performed under direct vision, and with minimal haemodynamic disturbance under local anaesthetic. Double-lumen tubes and endobronchial blockers can be inserted via the tracheostomy to achieve lung separation, in addition to commercially available lung isolation tracheostomy tubes (Tracheopartâ„¢). An algorithm for emergency lung separation when orotracheal airway instrumentation is not possible is presented in Figure 4.
(Enlarge Image)
Figure 4.
An algorithm for emergency lung separation when orotracheal airway management is not possible. DLT, double-lumen tube; ETT, endotracheal tube.
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