Erroneous Creation of a Surgical Airway Through the Thyrohyoid Membrane Kenneth N. Hiller, MD, and Carin A. Hagberg, MD This case report illustrates the importance of proper assessment, management, and creation of an emergent surgical airway. Assessment after the establishment of surgical airways should include confirmation of correct surgical site and appropriate location and depth of tracheostomy, tracheal tube, or catheter placement within the trachea. Supraglottic surgical airway access, as occurred in this case, can lead to laryngotracheal and esophageal injury. Early recognition and appropriate management of this complication can increase the likelihood of preservation of voice and airway function and minimize the extent of esophageal injury. (A&A Case Reports. 2014;3:88–90.)
I
nvasive surgical airway procedures are included in difficult airway algorithms as a method to secure the airway in either nonemergent or emergent situations. Fortunately, in the hospital setting, the incidence of “cannot intubate, cannot ventilate” scenarios that progress to the need to create an invasive surgical airway is low.1,2 This case report describes erroneous creation of a surgical airway through the cricothyroid membrane (CTM) in a patient after a blast injury affecting the face and airway and in whom bag and mask ventilation became difficult after multiple attempts to intubate the trachea. The clinical implications and significance of erroneous supraglottic surgical airway access are discussed. The patient gave permission for the authors to publish the report.
On arrival to the emergency department, a chest radiograph demonstrated endobronchial intubation with left lung collapse. The ETT was withdrawn an appropriate distance and bilateral lung ventilation was confirmed. The patient was taken to the operating room for creation of a formal tracheostomy. Initial surgical dissection (Fig. 1) revealed the ETT inserted through the thyrohyoid membrane. During creation of the open surgical tracheostomy, the ETT was removed, revealing airway trauma. A posterior view of the thyrohyoid membrane (Fig. 2) demonstrated injury at multiple supraglottic locations. Chest tomography revealed radiographic abnormalities on the left side of the hyoid bone (Fig. 3).
CASE DESCRIPTION
DISCUSSION
A 34-year-old previously healthy man exhibited altered consciousness after a methane explosion in an enclosed space resulted in 12% total body surface area burns to his face, shoulders, posterior arms, and back. Despite prehospital evaluation acknowledging several difficult airway predictors, including a small mouth opening, Mallampati III Class airway, 2-cm thyromental distance, and large neck circumference, the emergency flight team at the scene decided to secure the airway using rapid sequence induction, followed by direct laryngoscopy. Although ventilation via facemask was initially adequate, multiple attempts at direct laryngoscopy were subsequently performed, and tracheal intubation was unsuccessful. The airway became bloodied, and ventilation was inadequate via both facemask and supraglottic airway (King LT-D™). An emergent surgical airway was subsequently created, and tracheal placement of the endotracheal tube (ETT) was confirmed by capnography. From the Department of Anesthesiology, The University of Texas Medical School at Houston, Houston, Texas. Accepted for publication March 26, 2014. Funding: Work attributed to and financial support provided by the Department of Anesthesiology, The University of Texas Medical School at Houston. The authors declare no conflicts of interest. Address correspondence to Kenneth N. Hiller, MD, Department of Anes thesiology, The University of Texas Medical School at Houston, 6431 Fannin St., MSB 5.020, Houston, TX 77030. Address e-mail to Kenneth.N.Hiller@uth. tmc.edu. Copyright © 2014 International Anesthesia Research Society DOI: 10.1213/XAA.0000000000000091
88 cases-anesthesia-analgesia.org
The airway options described in the American Society of Anesthesiologists Guidelines on the Management of the Difficult Airway include surgical or percutaneous airway, jet ventilation, and retrograde intubation as invasive airway access procedures.3 If creation of an emergency surgical airway is necessary, anesthesiologists are more likely to perform a cricothyrotomy than a tracheostomy.4 To avoid injury to the vocal apparatus, each of the above techniques is usually performed at the level of the CTM, which is located below the laryngeal inlet and vocal cords (Fig. 4). Once completed, assessment of the result should include ensuring accurate CTM puncture, as well as appropriate location and depth of the tube or catheter within the trachea. The situation described in this case report is more likely to occur in the prehospital or combat setting, where there are fewer available resources including trained personnel, sufficient lighting, and appropriate equipment. These limitations have led the military to instruct field medics in emergency cricothyrotomy rather than tracheal intubation.a A review of retrospective military trauma registry data from a combined 21-month period found all 5 attempted prehospital cricothyrotomies were unsuccessful and resulted in airway-related deaths despite otherwise potentially survivable injuries.5 These outcomes, combined with dynamic, unpredictable prehospital environments, underscore the United States Marine Corps, training and education command, field medical service technician student manual, revised June 2013, 3–25 to 3–33. Available at: http://www.tecom.marines.mil/Portals/131/Docs/fmsthand.pdf. Accessed March 11, 2014.
a
October 1, 2014 • Volume 3 • Number 7
Figure 1. Endotracheal tube inserted through the thyrohyoid membrane. A = thyrohyoid membrane; B = thyroid cartilage; C = sternal notch. Figure 3. Radiographic abnormalities on the left side of the hyoid bone indicating trauma that occurred during prehospital surgical airway access.
Figure 2. Posterior view of the thyrohyoid membrane, with arrows indicating supraglottic trauma.
importance of appropriate technique and assessment of this procedure.6 Direct laryngoscopy and rigid esophagoscopy can be performed to evaluate the possibility of mucosal/cartilaginous injury and pharyngeal/esophageal injury, respectively. Timely, proper treatment is essential to preserve voice and airway function.7 Although this patient’s emergency airway provided critical oxygenation and ventilation, the multiple intubation attempts likely provoked the need to create a surgical airway. Inserting a laryngeal mask airway or other supraglottic airway before airway soiling might have avoided laryngeal injury. The erroneous creation of a surgical airway through the thyrohyoid membrane illustrates several key educational points. Highly trained airway managers should perform and master the important skill of cricothyrotomy. The first step in the performance of this lifesaving technique is accurate
October 1, 2014 • Volume 3 • Number 7
identification of the CTM. Many variables complicate accurate location of the CTM, including a thick/obese neck, which was present in this case.6 When non-anesthesiologists are the airway managers, preoperative evaluation for possible difficulty establishing a surgical airway is likely not as commonly performed as is assessment for possible difficult mask ventilation, laryngoscopy, and tracheal intubation. In 2003, the American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway recommended that anesthesiologists assess patients for possible difficult tracheostomy.8 Interestingly, the latest guidelines advise assessing for possible difficult surgical airway.3 Predictors of difficult cricothyrotomy include difficulty identifying CTM location and accessing the trachea through the anterior neck.6 Although the literature encourages anesthesiologists to mark the CTM location whenever there is a significant possibility for encountering a failed ventilation situation,6 this is likely not common practice. If it is performed, it may not be done correctly because anesthesiologists are not adept at CTM identification.9,10 Nonpalpation techniques that rely on fixed anatomic locations, such as the sternal notch, are subjective and do not consider patient-to-patient variability and neck position. The NAP4 study conducted by the Royal Society of Anaesthetists,11,12 as well as a meta-analysis of prehospital cricothyrotomy outcomes,13 found that cricothyrotomies performed surgically were more successful than when performed by needle or Seldinger technique. Although the surgical technique should provide direct anatomic visualization, this case report demonstrates that the CTM was not correctly identified. This problem is not unique to prehospital providers; the NAP4 study revealed that trained anesthesiologists failed to successfully create a surgical airway 64% of the time.11
cases-anesthesia-analgesia.org
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appropriately, and the patient did not lose his voice or experience further complications. Perhaps education, practice, and increased use of new technology, such as ultrasonography, could improve proper establishment of surgical airway access in future cases.E
Figure 4. External neck anatomy with proper placement site for a surgical tracheostomy. A = hyoid bone; B = thyrohyoid m embrane; C = thyroid cartilage; D = cricothyroid membrane; E = cricoid cartilage; F = surgical tracheostomy site (between second and third tracheal rings).
An initial step toward improved outcomes for cricothyrotomy by nonsurgeons may be the formulation of a reliable, standardized technique for CTM location. Suggestions for learning, practicing, and mastering cricothyrotomy include both didactic and hands-on instruction through lectures, simulation education, including basic airway anatomy (Fig. 4), and mannequin/cadaver/pig trachea workshops. However, although training produces improved laboratory results, translation of these skills into improved clinical outcomes has not occurred.14 We have a comprehensive education program at our institution, and its clinical efficacy is undergoing study. One of the most recent techniques used to teach identification of the CTM is ultrasonography.15 Experience with this technique could prove worthwhile when encountering an inability to ventilate the lungs during attempted awake or postinduction airway management.6 In conclusion, inadvertent thyrohyoid membrane puncture occurred during the creation of an emergent surgical airway. Fortunately, it was recognized and treated
90 cases-anesthesia-analgesia.org
REFERENCES 1. Kheterpal S, Han R, Tremper KK, Shanks A, Tait AR, O’Reilly M, Ludwig TA. Incidence and predictors of difficult and impossible mask ventilation. Anesthesiology 2006;105:885–91 2. Heard AM, Green RJ, Eakins P. The formulation and introduction of a “can’t intubate, can’t ventilate” algorithm into clinical practice. Anaesthesia 2009;64:601–8 3. American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 2013;118:251–70 4. Das P, Zhu H, Shah RK, Roberson DW, Berry J, Skinner ML. Tracheotomy-related catastrophic events: results of a national survey. Laryngoscope 2012;122:30–7 5. Mabry RL, Edens JW, Pearse L, Kelly JF, Harke H. Fatal airway injuries during Operation Enduring Freedom and Operation Iraqi Freedom. Prehosp Emerg Care 2010;14:272–7 6. Law JA, Broemling N, Cooper RM, Drolet P, Duggan LV, Griesdale DE, Hung OR, Jones PM, Kovacs G, Massey S, Morris IR, Mullen T, Murphy MF, Preston R, Naik VN, Scott J, Stacey S, Turkstra TP, Wong DT; Canadian Airway Focus Group. The difficult airway with recommendations for management–part 2–the anticipated difficult airway. Can J Anaesth 2013;60:1119–38 7. Schaefer SD. Management of acute blunt and penetrating external laryngeal trauma. Laryngoscope 2014;124:233–44 8. American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 2003;98:1269–77 9. Aslani A, Ng SC, Hurley M, McCarthy KF, McNicholas M, McCaul CL. Accuracy of identification of the cricothyroid membrane in female subjects using palpation: an observational study. Anesth Analg 2012;114:987–92 10. Hung O, Scott J, Mullen T, Murphy M. Waiting to exhale! Anesth Analg 2012;114:927–8 11. Cook TM, Woodall N, Frerk C; Fourth National Audit Project. Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1: anaesthesia. Br J Anaesth 2011;106:617–31 12. Cook TM, Woodall N, Harper J, Benger J; Fourth National Audit Project. Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 2: intensive care and emergency departments. Br J Anaesth 2011;106:632–42 13. Hubble MW, Wilfong DA, Brown LH, Hertelendy A, Benner RW. A meta-analysis of prehospital airway control techniques part II: alternative airway devices and cricothyrotomy success rates. Prehosp Emerg Care 2010;14:515–30 14. Hubert V, Duwat A, Deransy R, Mahjoub Y, Dupont H. Effect of simulation training on compliance with difficult airway management algorithms, technical ability, and skills retention for emergency cricothyrotomy. Anesthesiology 2014;120:999–1008 15. Kristensen MS. Ultrasonography in the management of the airway. Acta Anaesthesiol Scand 2011;55:1155–73
A & A case reports
I
nvasive surgical airway procedures are included in difficult airway algorithms as a method to secure the airway in either nonemergent or emergent situations. Fortunately, in the hospital setting, the incidence of “cannot intubate, cannot ventilate” scenarios that progress to the need to create an invasive surgical airway is low.1,2 This case report describes erroneous creation of a surgical airway through the cricothyroid membrane (CTM) in a patient after a blast injury affecting the face and airway and in whom bag and mask ventilation became difficult after multiple attempts to intubate the trachea. The clinical implications and significance of erroneous supraglottic surgical airway access are discussed. The patient gave permission for the authors to publish the report.
On arrival to the emergency department, a chest radiograph demonstrated endobronchial intubation with left lung collapse. The ETT was withdrawn an appropriate distance and bilateral lung ventilation was confirmed. The patient was taken to the operating room for creation of a formal tracheostomy. Initial surgical dissection (Fig. 1) revealed the ETT inserted through the thyrohyoid membrane. During creation of the open surgical tracheostomy, the ETT was removed, revealing airway trauma. A posterior view of the thyrohyoid membrane (Fig. 2) demonstrated injury at multiple supraglottic locations. Chest tomography revealed radiographic abnormalities on the left side of the hyoid bone (Fig. 3).
CASE DESCRIPTION
DISCUSSION
A 34-year-old previously healthy man exhibited altered consciousness after a methane explosion in an enclosed space resulted in 12% total body surface area burns to his face, shoulders, posterior arms, and back. Despite prehospital evaluation acknowledging several difficult airway predictors, including a small mouth opening, Mallampati III Class airway, 2-cm thyromental distance, and large neck circumference, the emergency flight team at the scene decided to secure the airway using rapid sequence induction, followed by direct laryngoscopy. Although ventilation via facemask was initially adequate, multiple attempts at direct laryngoscopy were subsequently performed, and tracheal intubation was unsuccessful. The airway became bloodied, and ventilation was inadequate via both facemask and supraglottic airway (King LT-D™). An emergent surgical airway was subsequently created, and tracheal placement of the endotracheal tube (ETT) was confirmed by capnography. From the Department of Anesthesiology, The University of Texas Medical School at Houston, Houston, Texas. Accepted for publication March 26, 2014. Funding: Work attributed to and financial support provided by the Department of Anesthesiology, The University of Texas Medical School at Houston. The authors declare no conflicts of interest. Address correspondence to Kenneth N. Hiller, MD, Department of Anes thesiology, The University of Texas Medical School at Houston, 6431 Fannin St., MSB 5.020, Houston, TX 77030. Address e-mail to Kenneth.N.Hiller@uth. tmc.edu. Copyright © 2014 International Anesthesia Research Society DOI: 10.1213/XAA.0000000000000091
88 cases-anesthesia-analgesia.org
The airway options described in the American Society of Anesthesiologists Guidelines on the Management of the Difficult Airway include surgical or percutaneous airway, jet ventilation, and retrograde intubation as invasive airway access procedures.3 If creation of an emergency surgical airway is necessary, anesthesiologists are more likely to perform a cricothyrotomy than a tracheostomy.4 To avoid injury to the vocal apparatus, each of the above techniques is usually performed at the level of the CTM, which is located below the laryngeal inlet and vocal cords (Fig. 4). Once completed, assessment of the result should include ensuring accurate CTM puncture, as well as appropriate location and depth of the tube or catheter within the trachea. The situation described in this case report is more likely to occur in the prehospital or combat setting, where there are fewer available resources including trained personnel, sufficient lighting, and appropriate equipment. These limitations have led the military to instruct field medics in emergency cricothyrotomy rather than tracheal intubation.a A review of retrospective military trauma registry data from a combined 21-month period found all 5 attempted prehospital cricothyrotomies were unsuccessful and resulted in airway-related deaths despite otherwise potentially survivable injuries.5 These outcomes, combined with dynamic, unpredictable prehospital environments, underscore the United States Marine Corps, training and education command, field medical service technician student manual, revised June 2013, 3–25 to 3–33. Available at: http://www.tecom.marines.mil/Portals/131/Docs/fmsthand.pdf. Accessed March 11, 2014.
a
October 1, 2014 • Volume 3 • Number 7
Figure 1. Endotracheal tube inserted through the thyrohyoid membrane. A = thyrohyoid membrane; B = thyroid cartilage; C = sternal notch. Figure 3. Radiographic abnormalities on the left side of the hyoid bone indicating trauma that occurred during prehospital surgical airway access.
Figure 2. Posterior view of the thyrohyoid membrane, with arrows indicating supraglottic trauma.
importance of appropriate technique and assessment of this procedure.6 Direct laryngoscopy and rigid esophagoscopy can be performed to evaluate the possibility of mucosal/cartilaginous injury and pharyngeal/esophageal injury, respectively. Timely, proper treatment is essential to preserve voice and airway function.7 Although this patient’s emergency airway provided critical oxygenation and ventilation, the multiple intubation attempts likely provoked the need to create a surgical airway. Inserting a laryngeal mask airway or other supraglottic airway before airway soiling might have avoided laryngeal injury. The erroneous creation of a surgical airway through the thyrohyoid membrane illustrates several key educational points. Highly trained airway managers should perform and master the important skill of cricothyrotomy. The first step in the performance of this lifesaving technique is accurate
October 1, 2014 • Volume 3 • Number 7
identification of the CTM. Many variables complicate accurate location of the CTM, including a thick/obese neck, which was present in this case.6 When non-anesthesiologists are the airway managers, preoperative evaluation for possible difficulty establishing a surgical airway is likely not as commonly performed as is assessment for possible difficult mask ventilation, laryngoscopy, and tracheal intubation. In 2003, the American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway recommended that anesthesiologists assess patients for possible difficult tracheostomy.8 Interestingly, the latest guidelines advise assessing for possible difficult surgical airway.3 Predictors of difficult cricothyrotomy include difficulty identifying CTM location and accessing the trachea through the anterior neck.6 Although the literature encourages anesthesiologists to mark the CTM location whenever there is a significant possibility for encountering a failed ventilation situation,6 this is likely not common practice. If it is performed, it may not be done correctly because anesthesiologists are not adept at CTM identification.9,10 Nonpalpation techniques that rely on fixed anatomic locations, such as the sternal notch, are subjective and do not consider patient-to-patient variability and neck position. The NAP4 study conducted by the Royal Society of Anaesthetists,11,12 as well as a meta-analysis of prehospital cricothyrotomy outcomes,13 found that cricothyrotomies performed surgically were more successful than when performed by needle or Seldinger technique. Although the surgical technique should provide direct anatomic visualization, this case report demonstrates that the CTM was not correctly identified. This problem is not unique to prehospital providers; the NAP4 study revealed that trained anesthesiologists failed to successfully create a surgical airway 64% of the time.11
cases-anesthesia-analgesia.org
89
appropriately, and the patient did not lose his voice or experience further complications. Perhaps education, practice, and increased use of new technology, such as ultrasonography, could improve proper establishment of surgical airway access in future cases.E
Figure 4. External neck anatomy with proper placement site for a surgical tracheostomy. A = hyoid bone; B = thyrohyoid m embrane; C = thyroid cartilage; D = cricothyroid membrane; E = cricoid cartilage; F = surgical tracheostomy site (between second and third tracheal rings).
An initial step toward improved outcomes for cricothyrotomy by nonsurgeons may be the formulation of a reliable, standardized technique for CTM location. Suggestions for learning, practicing, and mastering cricothyrotomy include both didactic and hands-on instruction through lectures, simulation education, including basic airway anatomy (Fig. 4), and mannequin/cadaver/pig trachea workshops. However, although training produces improved laboratory results, translation of these skills into improved clinical outcomes has not occurred.14 We have a comprehensive education program at our institution, and its clinical efficacy is undergoing study. One of the most recent techniques used to teach identification of the CTM is ultrasonography.15 Experience with this technique could prove worthwhile when encountering an inability to ventilate the lungs during attempted awake or postinduction airway management.6 In conclusion, inadvertent thyrohyoid membrane puncture occurred during the creation of an emergent surgical airway. Fortunately, it was recognized and treated
90 cases-anesthesia-analgesia.org
REFERENCES 1. Kheterpal S, Han R, Tremper KK, Shanks A, Tait AR, O’Reilly M, Ludwig TA. Incidence and predictors of difficult and impossible mask ventilation. Anesthesiology 2006;105:885–91 2. Heard AM, Green RJ, Eakins P. The formulation and introduction of a “can’t intubate, can’t ventilate” algorithm into clinical practice. Anaesthesia 2009;64:601–8 3. American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 2013;118:251–70 4. Das P, Zhu H, Shah RK, Roberson DW, Berry J, Skinner ML. Tracheotomy-related catastrophic events: results of a national survey. Laryngoscope 2012;122:30–7 5. Mabry RL, Edens JW, Pearse L, Kelly JF, Harke H. Fatal airway injuries during Operation Enduring Freedom and Operation Iraqi Freedom. Prehosp Emerg Care 2010;14:272–7 6. Law JA, Broemling N, Cooper RM, Drolet P, Duggan LV, Griesdale DE, Hung OR, Jones PM, Kovacs G, Massey S, Morris IR, Mullen T, Murphy MF, Preston R, Naik VN, Scott J, Stacey S, Turkstra TP, Wong DT; Canadian Airway Focus Group. The difficult airway with recommendations for management–part 2–the anticipated difficult airway. Can J Anaesth 2013;60:1119–38 7. Schaefer SD. Management of acute blunt and penetrating external laryngeal trauma. Laryngoscope 2014;124:233–44 8. American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 2003;98:1269–77 9. Aslani A, Ng SC, Hurley M, McCarthy KF, McNicholas M, McCaul CL. Accuracy of identification of the cricothyroid membrane in female subjects using palpation: an observational study. Anesth Analg 2012;114:987–92 10. Hung O, Scott J, Mullen T, Murphy M. Waiting to exhale! Anesth Analg 2012;114:927–8 11. Cook TM, Woodall N, Frerk C; Fourth National Audit Project. Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1: anaesthesia. Br J Anaesth 2011;106:617–31 12. Cook TM, Woodall N, Harper J, Benger J; Fourth National Audit Project. Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 2: intensive care and emergency departments. Br J Anaesth 2011;106:632–42 13. Hubble MW, Wilfong DA, Brown LH, Hertelendy A, Benner RW. A meta-analysis of prehospital airway control techniques part II: alternative airway devices and cricothyrotomy success rates. Prehosp Emerg Care 2010;14:515–30 14. Hubert V, Duwat A, Deransy R, Mahjoub Y, Dupont H. Effect of simulation training on compliance with difficult airway management algorithms, technical ability, and skills retention for emergency cricothyrotomy. Anesthesiology 2014;120:999–1008 15. Kristensen MS. Ultrasonography in the management of the airway. Acta Anaesthesiol Scand 2011;55:1155–73
A & A case reports
