You are about to start a busy Monday afternoon shift when you hear a radio call from EMS for a high-speed motor vehicle crash. The dispatcher tells you that the patients are 5 minutes away. The first patient that arrives is an unrestrained 23-year-old male driver. The patient has severe right-sided chest pain with moderate respiratory distress. His blood pressure is 102/54 mm Hg, his heart rate is 112 beats/min, and the pulse oximeter reads 92% on room air. You are concerned for a pneumothorax but wonder what else could explain his abnormal vital signs...
The second patient is the unrestrained 27-year-old female passenger from the same accident, with a chief complaint of chest pain, difficulty breathing, and shortness of breath. Her blood pressure is 120/70 mm Hg, her heart rate is 85 beats/min, and the pulse oximeter reads 97% on room air. On exam, the patient has decreased breath sounds on the right side. Again, pneumothorax sounds likely as you wait for the portable x-ray; you wonder if a bedside ultrasound could facilitate making the diagnosis...
A third patient then walks into triage. He is a 79-year-old man who has come in after a fall from standing and is complaining of rib pain. He is in moderate distress. His blood pressure is 140/90 mm Hg, his pulse is 90 beats/min, and his oxygen saturation is 97% on room air. His only complaint is extreme pain to his left chest. He tells you that his medical history is positive for type 2 diabetes mellitus, hypertension, and chronic obstructive pulmonary disease. He takes metformin, metoprolol, and inhaled tiotropium bromide. On physical exam, you see bruises to the left chest wall and can feel crepitus; you suspect multiple rib fractures and get ready to treat a third pneumothorax...
Traumatic injuries continue to be a major health concern in the United States. Unintentional injuries have become the fourth leading cause of death, now exceeding stroke.1 Trauma is also the leading cause of death, morbidity, hospitalization, and disability in Americans aged 1 year to 45 years. Blunt chest injuries are a particular concern, occurring in 12 persons per 1 million per day, with approximately one-third requiring hospital admission. Blunt thoracic traumatic injuries are responsible for 20% to 25% of all blunt trauma deaths.2
Motor vehicle crashes account for 70% to 80% of blunt chest trauma cases.3,4 Motor vehicle crashes can cause injury both by direct forces of impact as well as rapid deceleration from high speed. Other common causative mechanisms of blunt chest injuries include falls, blast injuries, barotrauma, and physical assault. In a review of 1696 patients with blunt chest trauma, injuries were considered to be minor in 710 patients (42%), intermediate in 740 (44%), and severe in 246 (15%).3 Global in-hospital mortality was low (5%), but increased to 37% when only patients with multiple severe injuries were considered. Thoracic skeletal fractures were present in 84% of these patients, while flail chest was diagnosed in 8%. Pulmonary contusion was diagnosed in 16% of the patients, diaphragmatic rupture was present in 2%, and tracheobronchial injury in 0.4%.3
Rib fractures are identified in up to two-thirds of chest trauma patients who receive radiographic imaging.4-6 Rib fractures are some of the most common injuries in the elderly, accounting for approximately 12% of all fractures, with increasing incidence as this population gets older.7 Emergency clinicians must have a low threshold of suspicion for rib fractures and bony skeletal injury in patients with blunt thoracic trauma, as up to 50% of fractures may be undetected radiographically.6 This is important, as morbidity and mortality can be significant from chest wall injuries alone. One review of 77 elderly patients reported a 38% rate of respiratory complication, with 8% mortality, associated with isolated rib fractures.8 Mortality associated with a flail chest is as high as 16%.9
Sternal fractures occur in approximately 8% of severe blunt chest trauma patients,10,11 90% of which are secondary to motor vehicle crashes.11,12 One study of 200 patients with sternal fracture reported an estimated 30% incidence of concomitant chest injuries.12 The significance of associated intrathoracic injury associated with sternal fractures is underscored by the fact that fractures of the sternum have been associated with cardiac contusion in 20% to 40% of cases.13
Pulmonary contusions, pneumothorax, and hemothorax occur in 30% to 50% of patients with severe blunt chest trauma managed in trauma centers. 4,11,13-17 Diaphragmatic tears secondary to blunt trauma are uncommon, but they have potential for delayed complications (eg, diaphragmatic hernia) if not identified. Up to 6% of patients with blunt abdominal trauma have had traumatic diaphragmatic rupture diagnosed during exploratory laparotomy.18 Clinically significant tracheobronchial injuries are rarely identified in blunt chest trauma, and are reported in < 1% of cases.19
This issue of Emergency Medicine Practice provides an evidence-based review of blunt chest trauma with a focus on injuries involving the chest wall, lungs, and pleura. Best-practice recommendations are made to facilitate clinical decision-making and appropriate resource utilization.
PubMed was searched using the following terms: blunt chest trauma, blunt chest injury, traumatic pneumothorax, traumatic hemothorax, pulmonary contusion, rib fractures, flail chest, clavicle fracture, scapula fracture, sternoclavicular dislocation, and sternum fracture. Articles were selected if they were relevant to emergency care and focused on adult patients. References from the papers were also utilized. Guidelines from the Eastern Association for the Surgery of Trauma (EAST) and the American College of Radiology (ACR) Appropriateness Criteria® were included as found on the National Guideline Clearinghouse site at www.guideline.gov.
Review of the literature clearly demonstrated that there is a paucity of well-designed prospective studies; much of the evidence is based on retrospective analysis of databases and cohort studies. Consequently, much of the literature suffers from selection bias and from being underpowered.
Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.
To help the reader judge the strength of each reference, pertinent information about the study is included in bold type following the reference, where available. In addition, the most informative references cited in this paper, as determined by the authors, are noted by an asterisk (*) next to the number of the reference.
|Table of Contents|
Why to Use
Placing the ETT too deep may cause right mainstem intubation, hypoxemia, and pneumothorax. However, placing the ETT too shallow may risk injury to the vocal cords and accidental extubation. Standard approaches to verify ETT depth (eg, bilateral auscultation) are insensitive. Use of lower tidal volumes appears to prevent the development of acute respiratory distress syndrome, even in patients who do not have lung injury.
When to Use
Use in adult patients (aged > 20 years) requiring orotracheal intubation.
Chula formula: ETT depth = 0.1 * [height (cm)] + 4
Joshua Farkas, MD
Obtain chest radiograph and measurement of CO2 level (eg, end-tidal CO2 or blood gas analysis) to confirm ETT position and adequacy of ventilation.
The Chula formula was developed and validated by Techanivate et al (2005) at King Chulalongkorn Memorial Hospital in Thailand. The authors prospectively validated the use of this formula among 100 patients in Thailand. Patients were intubated and the ETT placed according to the formula. Subsequently, a bronchoscope was used to determine the relationship among the ETT, carina, and vocal cords. The distance between the ETT and carina ranged between 1.9-7.5 cm. No patient was at immediate risk of endobronchial intubation. The upper border of the ETT cuff was always > 1.9 cm below the vocal cords, avoiding risk of laryngeal trauma or inadvertent extubation.
Pak et al in 2010 and Hunyady et al in 2008 developed similar assessments of optimal ETT placement. The average of the 3 scores (Pak, Hunyady, and Chula) is nearly identical to the Chula formula.
Anchalee Techanivate, MD
The Blast Lung Injury Severity Score stratifies primary blast lung injuries into 3 categories to guide ventilator treatment.
Why to Use
The Blast Lung Injury (BLI) Severity Score is useful in guiding triage decisions in the setting of mass casualties, determining ventilation treatment, and predicting outcomes. BLI severity correlates with the likelihood of developing acute respiratory distress syndrome (ARDS), and can be helpful to delineate patients who will require more aggressive and potentially unconventional respiratory care (eg, nitric oxide, high-frequency jet ventilation, independent lung ventilation, or extracorporeal membrane oxygenation).
When to Use
Use the BLI Severity Score in patients who have sustained blast injury and have respiratory symptoms (eg, cough, cyanosis, dyspnea, hemoptysis).
Intubated patients require the following ventilation management:
Jennie Kim, MD
Travis Polk, MD
The original BLI Severity Score was proposed in 1999 by Pizov et al. The study evaluated 15 patients with primary BLI after explosions on 2 civilian buses. BLI Severity scores were compared to Murray scores for acute lung injury at 6 and 24 hours after injury; at 24 hours, there was good correlation between the proposed BLI score and the modified Murray score.
Three of the 3 patients (100%) with severe BLI who were still alive after 24 hours (1 patient died within 24 hours from intrapulmonary hemorrhage after being placed on extracorporeal membrane oxygenation) and 2 of 6 patients (33%) with moderate BLI developed acute respiratory distress syndrome (ARDS) (Murray score > 2.5). None of the 5 patients with mild BLI developed ARDS. Other unconventional respiratory therapies such as independent lung ventilation, high-frequency jet ventilation, and nitric oxide were used in patients with severe BLI with improvements in their PaO2 levels. When comparing mortality rates, 4 patients with severe BLI died, all 6 patients with moderate BLI survived, and 1 of the 5 patients with mild BLI subsequently died from a traumatic head injury.
One year after the study by Pizov et al, Hirshberg et al conducted a follow-up study of the 11 surviving original patients. None of the 11 survivors had pulmonary-related complaints, and lung physical examinations were normal with complete resolution of chest radiograph findings.
In comparison, Avidan et al, in 2005, evaluated 29 patients with primary BLI, and only 1 patient had died (death occurred 24 days after admission from sepsis and multiple organ failure). The authors concluded that death because of BLI in patients who survived the explosion is unusual. Although these 29 patients were not categorized by BLI severity scores, there were 7 patients with PaO2 / FiO2 ratios < 60, 4 patients requiring positive end-expiratory pressure (PEEP) > 10 cm H2O, and 3 patients requiring unconventional therapies such as high-frequency ventilation or nitric oxide inhalations. The decreased mortality rate compared to Pizov et al, despite the presence of patients with characteristics of severe BLI, may be attributed to improvements in critical care and respiratory management.
The study also assessed long-term outcomes by contacting 21 of 28 survivors (75%) from 6 months to 21 years after discharge. Sixteen patients (76%) were free of respiratory symptoms and did not require respiratory therapy. Five patients (24%) reported respiratory symptoms but 2 of the 5 had a past medical history of asthma and another 2 of the 5 were contacted less than 1 year after injury.
Reuven Pizov, MD
Copyright © MDCalc • Reprinted with permission.
Eric J. Morley, MD, MS ; Scott Johnson, MD; Evan Leibner, MD, PhD; Jawad Shahid, MD
June 1, 2016
July 1, 2019
Upon completion of this article, you should be able to:
Physician CME Information
Date of Original Release: June 1, 2016. Date of most recent review: May 10, 2016. Termination date: June 1, 2019.
Accreditation: EB Medicine is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians. This activity has been planned and implemented in accordance with the Essential Areas and Policies of the ACCME.
Credit Designation: EB Medicine designates this enduring material for a maximum of 4 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
ACEP Accreditation: Emergency Medicine Practice is approved by the American College of Emergency Physicians for 48 hours of ACEP Category I credit per annual subscription.
AAFP Accreditation: This Medical Journal activity, Emergency Medicine Practice, has been reviewed and is acceptable for up to 48 Prescribed credits by the American Academy of Family Physicians per year. AAFP accreditation begins July 1, 2015. Term of approval is for one year from this date. Each issue is approved for 4 Prescribed credits. Credit may be claimed for one year from the date of each issue. Physicians should claim only the credit commensurate with the extent of their participation in the activity.
AOA Accreditation: Emergency Medicine Practice is eligible for up to 48 American Osteopathic Association Category 2-A or 2-B credit hours per year.
ABIM Accreditation: Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to 4 MOC points in the American Board of Internal Medicine’s (ABIM) Maintenance of Certification (MOC) program. Participants will earn MOC points equivalent to the amount of CME credits claimed for the activity. It is the CME activity provider’s responsibility to submit participant completion information to ACCME for the purpose of granting ABIM MOC credit.
Specialty CME: Included as part of the 4 credits, this CME activity is eligible for 4 Trauma CME credits, subject to your state and institutional approval.
Needs Assessment: The need for this educational activity was determined by a survey of medical staff, including the editorial board of this publication; review of morbidity and mortality data from the CDC, AHA, NCHS, and ACEP; and evaluation of prior activities for emergency physicians.
Target Audience: This enduring material is designed for emergency medicine physicians, physician assistants, nurse practitioners, and residents.
Goals: Upon completion of this activity, you should be able to: (1) demonstrate medical decision-making based on the strongest clinical evidence; (2) cost-effectively diagnose and treat the most critical presentations; and (3) describe the most common medicolegal pitfalls for each topic covered.
Objectives: Upon completion of this article, you should be able to: (1) summarize the work-up, disposition, and immediate treatment of blunt thoracic trauma patients; (2) assess the benefits and pitfalls of different imaging modalities; and (3) describe different methods of thoracic decompression of pneumothorax and hemothorax and select patients who require admission.
Discussion of Investigational Information: As part of the journal, faculty may be presenting investigational information about pharmaceutical products that is outside Food and Drug Administration–approved labeling. Information presented as part of this activity is intended solely as continuing medical education and is not intended to promote off-label use of any pharmaceutical product.
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Commercial Support: This issue of Emergency Medicine Practice did not receive any commercial support.
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