Practice Teaching case report pressure, blunt injury from the blast wave and burns.1 Emergency battlefield cricothyrotomy To meet these challenges, medics re- ceive training that prepares them to treat The case: A 19-year-old Afghan man was hospital 4 hours after the injury oc- common, preventable causes of death on critically injured after a blast from an im- curred, his vital signs were stable and his the battlefield, including acute airway ob- provised explosive device. A Canadian airway was secure. In the operating the- struction, tension pneumothorax and Forces medic treated him within minutes atre, we stabilized his facial wounds, exsanguination from injury to the ex- of the injury. On initial assessment in the converted his cricothyrotomy to a formal tremities, and it prioritizes these treat- field, the man was conscious and breath- , inserted a and ments based on the realities of combat ing despite extensive facial injuries in- amputated his left arm and leg. The pa- situations.2 For example, while grave volving the mouth, oral cavity and man- tient survived his injuries and was even- danger from hostile action persists, only dible. He had also lost parts of his left tually discharged from hospital. tourniquet placement is used to control forearm and lower left leg in the explo- arterial extremity hemorrhage. After pa- sion, which had caused extensive soft tis- tients are removed to a safer location, sue, neurovascular and bone injury. Be- Caring for trauma victims on the battle- acute airway and breathing issues are cause of arterial hemorrhage from his field is difficult. Medics often work under managed. extremities, the medic placed tourni- fire in blackout conditions and extreme Among other things, tactical combat quets on both injured limbs (Figure 1). temperatures, and on rugged terrain. The casualty care recommends early con- The patient was transported by land biggest challenge is that medics work in- sideration of open surgical cricothyrot- ambulance to a medical aid station lo- dependently despite a lack of trauma ex- omy because inexperienced military cated 30 minutes away. The facility con- perience before deployment. Battlefield medics are unlikely to intubate battlefield sisted of a simple resuscitation bay where injuries are challenging to manage, even trauma patients successfully.2 Emer- medics had access to supplemental oxy- for experienced clinicians. For example, gency cricothyrotomy is a dramatic, life- gen, better lighting, a warmer environ- blast trauma may include multiple in- saving procedure used to gain prompt ment and more monitoring equipment; juries, such as penetrating injuries from access to an otherwise compromised however, no physician was present. On shrapnel, hyperbaric injury from over- and inaccessible airway. Before deploy- arrival, the patient was tachypneic with a respiratory rate of 35 breaths/min, his oxygen saturation was 80%, and he was beginning to inhale blood. His blood pressure was 100/60 mm Hg, and his pulse was 130 beats/min. The medic ad- ministered supplemental oxygen, but the oxygen saturation remained under 90%. He decided to definitively control the pa- tient’s airway, but was uncomfortable in sedating and intubating the patient. In- stead, the medic performed an open sur- gical cricothyrotomy without complica- tion (Figure 1). Upon further assessment, the medic found an open chest wound and treated it with a needle thoracostomy and an occlusive dressing. The patient remained tachycardic but normoten- sive. The medic resuscitated him with a hypertonic saline solution adminis- tered intravenously. The patient also received intravenous antibiotics. Figure 1: A 19-year-old Afghan man sustained extensive facial injuries and lost parts of The patient was evacuated by heli- his left forearm and left lower leg after a blast from an improvised explosive device, copter to a field hospital at Kandahar causing extensive soft tissue, neurovascular and bone injury. A medic performed an Airfield, where we continued treating his open surgical cricothyrotomy to secure the man’s airway.

DOI:10.1503/cmaj.080036 injuries. When the patient arrived at the

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tion and oxygenation are impaired. Emergency cricothyrotomy is recom- mended when definitive control of the airway is required and other options have been exhausted (Box 1). Although many advanced methods of securing airways are available to anesthesiologists, military medics have limited options because of inexperience. Canadian Forces medics are taught to consider early surgical crico- after 2 failed attempts to se- cure the airway by other means, or after 1 failed attempt in the presence of uncor- rectable hypoxia and impaired ventila- tion. Cricothyrotomy should be immedi- ately considered in the presence of mechanical airway obstruction. For Figure 2: Surface landmarks for performing cricothyrotomy. medics working on the battlefield, im- mediate cricothyrotomy is often required because mechanical airway obstruction ing to Afghanistan, military medics par- skin edges apart after the cut is made. A commonly occurs from penetrating or ticipate in a Canadian Forces trauma- number 15 scalpel is used to make a blast injury to the face and neck. management course, using simulators longitudinal midline incision, about and animal models to practise cricothy- 1.5 cm in length, from the thyroid carti- Conclusion rotomy and other skills. lage to the (Figure 2). A DiGiacomo and colleagues de- longitudinal incision is preferred to Although there are differences between scribed the technique of surgical avoid bleeding complications from an- managing trauma on a battlefield and cricothyrotomy in detail.3 To perform a terior neck veins. The incision should managing trauma in civilian settings, cricothryotomy, an endotracheal or tra- cut through the skin and subcutaneous there are also similarities, particularly in cheotomy tube of appropriate size is tissues down to the thyroid and cricoid remote, rural areas where trauma practi- prepared. A surgeon, if he or she is cartilages, exposing the cricothyroid tioners must deal with critical injuries re- right-handed, then stands on the pa- membrane (Figure 3). The scalpel is lated to farming, forestry and mining, tient’s right side and stabilizes the then used to make a transverse stab in- often without access to specialists and cricoid with the thumb and index finger cision through the membrane into the with enormous distances to travel in of his or her left hand, applying a slight airway. The handle of the scalpel (or a harsh climates. There is a need to en- downward pressure to help draw the hemostat) is then used to dilate the hance trauma-management skills in rural opening in the membrane. Laying the areas,5 and a number of courses have scalpel aside, the previously prepared been developed including courses offered tube is inserted into the , the cuff is inflated, and the tube is secured to the patient’s neck. A stitch can be used to Box 1: Circumstances in which to secure the tube, but medics are taught consider cricothyrotomy to use a safety pin. Clinical examination Cricothyrotomy is recommended if and other adjunct tests, such as capnog- • there is a need for a definitive air- raphy if available, are performed to way, and 2 attempts* to secure the confirm tube placement in the trachea. airway using other means have failed; or Many physicians and medics may hesitate to perform emergency cricothy- • the patient has impaired venti- lation and uncorrectable hypoxia, rotomy because of inexperience or anx- and 1 attempt to secure the airway iety, thereby potentially increasing air- using other means has failed; or way trauma from further intubation • the patient has mechanical airway attempts and increasing the risk of poor obstruction (e.g., facial fractures, outcomes caused by hypoxia. To reduce direct airway injury, blood, broken

delays and minimize improvization, teeth, vomit). Figure 3: Surgical anatomy for cricothy- “difficult airway” guidelines have been *The threshold of 2 attempts should be in- rotomy. Reproduced with permission creased if the clinician is familiar with other developed to help physicians manage advanced methods to secure the patient’s from Lippincott Williams & Wilkins these stressful situations.4 Prompt ac- airway. (Walls RM et al.6) © 2000. tion is recommended whenever ventila-

1134 CMAJ • April 22, 2008 • 178(9) Practice

by the American College of Surgeons, in- LCdr John C. Macdonald MD Competing interests: None declared. cluding advanced trauma life support and Department of Critical Care Medicine rural trauma team development. University of Ottawa The Canadian Forces Health Ser- Ottawa, Ont. REFERENCES vices developed its tactical combat ca- Canadian Field Hospital 1. DePalma RG, Burris DG, Champion HR, et al. Canadian Forces Base Petawawa Blast injuries. N Engl J Med 2005;352:1335-42. sualty care course for its military 2. Butler FK Jr, Hagmann J, Butler EG. Tactical com- medics to prepare them to treat battle- Canadian Forces Health Services bat casualty care in special operations. Mil Med field injuries. This course provides re- Petawawa, Ont. 1996;161(Suppl):3-16. Maj Homer C.N. Tien MD MSc 3. DiGiacomo C, Neshat KK, Angus LD, et al. Emer- alistic treatment algorithms for gency cricothyrotomy. Mil Med 2003;168:541-4. Department of Surgery medics, taking into account their rela- 4. American Society of Anesthesiologists Task Force. Sunnybrook Health Sciences Centre Practice guidelines for the management of the diffi- tive clinical inexperience. In addition, University of Toronto cult airway. An update report by the American Society it uses simulators and animal models of Anesthesiologists task force on management of Toronto, Ont. the difficult airway. Anesthesiology 2003;98:1269-77. to teach procedural skills, concentrat- Canadian Field Hospital 5. Rowe BH, Therrien S, Johnson C. Regional varia- ing on open surgical cricothyrotomy tions of northern health. The epidemic of fatal Canadian Forces Base Petawawa trauma in northeastern Ontario. Can J Public for managing difficult airway situa- Canadian Forces Health Services Health 1995;86:249-54. tions. This approach to airway man- Petawawa, Ont. 6. Walls RM, Murphy MF, Luten RC, et al, editors. Manual of emergency , 2nd agement may also benefit trauma vic- edition. Philadelphia: Lippincott, Williams & tims beyond the battlefield. This article has been peer reviewed. Wilkins; 2004. p.162.

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