Triaging the hit-by-car patient (Proceedings)
The role of the veterinary technician in traumatic emergencies is pivotal to the survival of the incoming patient. The physical exam must be quick, thorough, and concise. Utilization of all technical skills from careful visualization, palpation, and auscultation is of the utmost importance. The use of emergency equipment is also useful, but should not be a substitute for a proper physical exam. The following outline summarizes a systemic approach to the most common traumatic emergency, the hit-by-car (HBC).
The airway should always be evaluated immediately upon arrival of the HBC. As a rule of thumb, one must remove the most immediate threats of life first, the whole concept behind triage. If a patient presents breathing, note that this does not ensure a patent airway. Before any action is taken, visually watch both the respiratory effort and respiratory pattern. Are chest expansions adequate? Keep in mind that the patient just received a traumatic injury, rode in an automobile, and is now surrounded by strangers. The first evaluation of the respiratory system, therefore, although diagnostic, should be repeated after several minutes to several hours. Examples of common respiratory patterns secondary to trauma include abdominal breathing, paradoxical breathing, and shallow or poor chest expansions.
Note that these are patterns of respirations. They do not indicate a number. Tachypnea (elevation of the respiratory rate) is simply a number. It does not mark a pattern of respiration, or the effort of respiration. In traumatic injuries such as the HBC, most patients will be tachypnic from stress alone. Therefore, it is by the pattern of the respirations that can characterize the nature of the injury. For example, abdominal breathing can indicate a diaphragmatic hernia, severe pulmonary contusions, pneumothorax, hemothorax, severe pain, or may indicate a metabolic abnormality such as acidosis secondary to poor perfusion. Paradoxical breathing can indicate a diaphragmatic hernia as well as blunt chest trauma, or can suggest a more severe diagnosis such as a cervical injury. Shallow or poor chest expansion can be a sign of shock, severe pneumothorax or hemothorax, an obstructive airway, atelectasis, pain, or pulmonary parenchymal contusions. In any situation, if abnormal respiratory patterns are present, minimize the stress to the patient and administer oxygen therapy in the least stressful route. Evaluate other clinical signs of respiratory insufficiency such as mucus membrane color and pulse quality, to further assess the patient's immediate needs. Again, counting the number of respirations is important, but not as critical as characterizing the pattern. Recommended oxygen therapy is listed as follows: mask: 3-5 lpm, oxygen cage at least 40%, and intranasal catheter insufflation at 50-100ml/kg/min.A quick, simple evaluation of the mucus membranes should also be a part of the check of the respiratory system. Note that in any traumatic injury, frequent evaluation of the membrane color is indicated. If a patient presents with normal, pink membranes but abnormal respiratory rate and pattern, the patient may not be hemodynamically stable. Repeat analysis of the membranes is essential. Note that pale membranes are an indication of a variety of incidences, from anemia to pain to hypoventilation. Again, note the respiratory pattern and respiratory effort to make a proper assessment of the patient's status in a timely fashion. Similarly, white mucus membranes, although abnormal, may not necessarily indicate a problem with the airway or respiratory system. White membranes may mean severe pain, hypothermia, shock, or ongoing blood loss. However, in addition to an abnormal respiratory pattern and rate/effort, the white membranes may suggest hypoventilation and the technician must administer oxygen in the least stressful route immediately. Cyanosis, or blue mucous membranes, indicates severe decompensation and respiratory shut down. Immediate action should be taken to reoxygenate the patient in the best effective manner.
Auscultation is the next step in evaluating the respiratory system. The patient should be sternal (if possible) and elimination of environmental noise for proper evaluation. If-possible, the patient should be refrained from panting or open mouth breathing, in order to auscult lung parenchyma and not referred airway noise. Frequent findings in the HBC patient auscultation include harsh lung sounds, decreased or absence of lung sounds, or guttural sounds in the thoracic area. Harsh lung sounds can be heard either ventrally or dorsally, either on inspiration or expiration, and may be isolated to the side of impact. Observe the respiratory pattern, respiratory effort, mucous membrane color, and utilize tools such as pulse oximetry or arterial blood gas analysis only as an extension to the physical exam findings. Administer oxygen if harsh lung sounds are present despite normal pulse oximeter values if the patient has any abnormal respiratory patterns or increased effort to ensure adequate oxygen exchange. Radiograph the thorax once the patient has been thoroughly evaluated and is not appear stressed. Thoracocentesis should not be attempted initially if there is no evidence of a pneumothorax on radiographs and the patient has a normal respiratory rate and effort.