If a patient is felt to be inadequately oxygenating or ventilating or is unable to appropriately protect their airway, rapid assessment of the patient’s airway must occur with a proper plan to establish a controlled and definitive airway. Benumof describes an 11-step examination of the airway to help determine the possibility of difficult intubation. Many of the steps can be performed in the trauma patient.

The length of the upper incisors, presence of an overbite, ability to prognath the jaw, inter-incisor distance, visibility of the uvula, shape of the palate, mandibular space compliance, thyromental distance, and the length and thickness of the neck may be assessed in many trauma patients. The range of motion of the head and neck are usually unable to be evaluated due to cervical spine immobilization.

The American Society of Anesthesiology has modified the 2003 difficult airway algorithm to account for trauma patients. A stable patient with a recognized difficult airway would likely require an awake, fiber-optic intubation. Topicalization of the oropharynx and laryngopharynx with a local anesthetic should be considered as time permits to aid the intubation process, provide patient comfort, and decrease likelihood of coughing and “bucking” after intubation, which risks inadvertent extubation, undesired cervical spine movement, and potentially dangerous hemodynamic swings. The deviation from the traditional difficult airway algorithm is that if the patient is unable to be intubated in this manner, it is unlikely that their surgical procedure can be cancelled or postponed, and surgical acquisition of an airway (awake tracheostomy) would most likely be necessary. Likewise, if the patient is uncooperative, unstable, or unconscious, the ability to awaken them in the event of an unanticipated difficult airway is diminished and the likelihood of requiring a surgical airway is increased.

In the patient without a suspected difficult intubation, there is no evidence that any technique is better than anesthetized intubation with direct laryngoscopy and manual axial inline stabilization (MAIS). Stabilization of the cervical spine is part of the standard of care for trauma patients as approximately 2 % of all blunt trauma patients have a cervical spine injury. The risk of cervical spine injury is increased in patients with a Glascow Coma Score of <8 (Table 46.2). When the decision to intubate a trauma patient has been made, the procedure should be performed with MAIS and concurrent cricoid pressure. An assistant maintains the head and neck in a neutral position while the trachea is intubated to limit the degree of cervical spine motion. Also, trauma patients are treated as full-stomachs because they typically have an unknown last oral intake status, necessitating cricoid pressure and rapid sequence induction. Both MAIS and cricoid pressure have been shown to worsen glottic views with direct laryngoscopy. External laryngeal manipulation, in particular backwards, upwards, and rightwards pressure (BURP) of the thyroid cartilage, was found to improve glottic views. Once intubated, pressure control (PC) ventilation is most often utilized with inspiratory pressures adjusted to maintain tidal volumes of 5–10 cm³/kg with positive end-expiratory pressure (PEEP) of 5–10 cm H₂O. Caution must be exercised upon initiation of positive pressure ventilation. In an under-resuscitated patient, hemodynamic collapse may occur as the positive ventilation pressures decrease venous return.

In addition to fiber-optic intubation, one has a number of options to facilitate intubation. Devices include Glidescope^®, AirTraq^® laryngoscope, Bullard, and/or a lighted stylette. Blind nasal intubation can also be performed but is often avoided if there is any suspicion of nasal, nasopharyngeal, or skull base trauma because of the possibility of inadvertent insertion of the tube into the cranial vault via a fractured cribriform plate. A study performed using fluoroscopic imaging showed decreased cervical motion when the AirTraq^® was used as the intubating device when compared to a standard Macintosh blade, which could be beneficial for patients with suspected cervical spine pathology. If blood or excess secretions are present around the glottic opening, visualization with fiber-optic devices such as a fiber-optic bronchoscope or Glidescope^® could be greatly reduced. With the presence of blood in the laryngopharynx and the inability to insert a laryngoscope blade or blindly pass a nasotracheal tube due to maxillofacial and nasal trauma, a retrograde wire technique is a possible alternative in a stable patient.

When only partial glottic views are obtained with laryngoscopy, a gum elastic bougie can be used to assist tracheal intubation. Several studies have shown a high success rate when utilizing the gum elastic bougie in cases of difficult intubation. Also, supraglottic devices such as the laryngeal mask airway (LMA), King LT™, and combitube may be considered in the difficult intubation scenario. While not providing a “definitive” airway, they enable ventilation and oxygenation until a definitive airway is obtained. The intubating LMA allows for ventilation of the patient as well as facilitating blind or fiber-optically assisted passage of an endotracheal tube or bougie.

Should insertion of an endotracheal tube, either via laryngoscopy, blind nasal passage, or passage through a supraglottic device not be possible, acquisition of a surgical airway may be indicated prior to aspiration, hypoxemia, or significant hypoventilation. If intubation is unsuccessful and tracheostomy or cricothyrotomy cannot be immediately performed, the availability of a jet ventilator and transtracheal jet ventilation can provide life-sustaining oxygenation until a surgical airway can be obtained. Assurance of intratracheal catheter placement is imperative when performing transtracheal jet ventilation because the massive subcutaneous emphysema that could result from jet ventilation of subcutaneous tissues will only further impair attempts at surgical airway acquisition. One medical provider should be assigned the sole task maintaining the intratracheal position of the transtracheal catheter. Additionally, caution must be undertaken to ensure that there is not an obstruction upstream from the transtracheal catheter such that exhalation is impaired or impossible. Pulmonary hyperdistension can result in pulmonary volutrauma, tracheal injury, or hemodynamic collapse by dynamic hyperdistension.

After the establishment of a secure airway and the confirmation of adequate oxygenation and ventilation, attention then turns to circulation. Second only to unsurvivable neurologic injury, exsanguination is a leading cause of death and is responsible for most trauma-related mortality in the early hours after presenting to the trauma bay. Mortality rates were >90 % in the 1970s when massive transfusions were necessitated. With advances in trauma care and transfusion medicine, mortality rates are now between 30 and 70 %.

Adequate venous access is vital to the resuscitation of a trauma patient. According to Poiseuille’s Law, venous cannulas that are shorter in length and wider in diameter will allow higher flow rates. Two large bore peripheral intravenous catheters are preferable over smaller diameter access. The location of venous access should be supradiagphragmatic if at all possible so that if there is a need for caval clamping in the event of intra-abdominal trauma, one will still have venous access. Large bore central access, such as 7–9 French catheters allow for the administration of large volumes at high flow rates. If only smaller gauge (that is, 20 gauge) peripheral access can be obtained, a Rapid Infusion Catheter (RIC™) of 6–8.5 French may be considered and can be inserted via Seldinger technique. This is accomplished by inserting a guide-wire through the existing angiocatheter, removing the catheter, cutting the skin to allow passage of the sheath and the dilator, and then removing the dilator leaving only the sheath in the vein. Another option to consider is central venous access with the best option often being the subclavian vein. The subclavian vein is effectively stented open with fibrous interconnective tissue and may be accessed even when markedly hypovolemic. When selecting which side to obtain subclavian venous access, the best choice is to select whichever side might already have a chest tube in place. By doing so, if there is an inadvertent pleural puncture, there will not be the risk for a tension pneumothorax and the need for another chest tube.

If venous access cannot be obtained in a timely fashion, intraosseous (IO) access is another option. There are specific IO kits, but should they not be available, one can use a Tuohy needle. When in the IO space one should be able to withdraw marrow, which can be sent for all venous labs desired. If marrow is unable to be withdrawn, the IO access should be considered malpositioned. Additionally, in a fashion similar to that described with transtracheal catheter ventilation, the IO catheter must be securely fastened. Should it become malpositioned while providing large volumes of fluid, the patient is at significant risk of developing compartment syndrome.

Fluid resuscitation of trauma patients has long been debated. No absolute conclusions have yet been made as to what is the best resuscitative fluid therapy. Ringer’s lactate solution (LR) had been the most widely studied isotonic fluid. Isotonic sodium chloride solution (NS) may also be used, but when given in large volumes it can cause hyperchloremic acidosis in patients already predisposed to acidosis. Recent interest in hypertonic saline (HTS) and hypertonic saline with dextrose (HTS-D) has led to several studies. The military utilizes hypertonic saline in the field largely for its ability to expand intravascular volume significantly more than the equivalent volumes of isotonic saline, thus allowing more effect with less cost in weight carried by medics. Albumin and hydroxyethyl starch at several different concentrations has also been studied. No one fluid has proven to be superior; however, according to one large retrospective study, resuscitation with L-isomer LR may be the least detrimental in terms of invoking less immune dysfunction and electrolyte abnormalities.

Large volume resuscitation has been associated with abdominal compartment syndrome, extremity compartment syndrome, pulmonary edema, and immune system dysfunction as well as other adverse outcomes. Therefore, goal-directed therapy, including fluid resuscitation and vasopressin (4 units IV), has been described to limit these effects. Hypotensive resuscitation by attempting to achieve mean arterial blood pressures between 40 and 60 mmHg has been associated with less blood loss, improved tissue oxygenation, and less acidemia and coagulopathy in patients able to be rapidly transported to Level 1 Trauma Centers to receive definitive care. However, prolonged hypotension (more than 90 min) was associated with increased organ damage. Additionally, all fluids should be warmed as they are infused to prevent hypothermia and worsening of coagulopathy. Significant hypothermia is an independent predictor of morbidity and mortality in trauma patients.

Traditionally, blood product transfusion is started if 2 l of LR or NS is insufficient to reverse the signs of shock. The Assessment of Blood Consumption (ABC) score has been developed and validated by a multicenter study as a predictor of massive transfusion. Massive transfusion has typically been described as transfusing ≥10 units of packed red blood cells (PRBC) within a 24-h period. The ABC score is based on four parameters, each receiving a score of either 0 (absent) or 1 (present). A score of ≥2 is considered positive for predicting massive transfusion. The parameters include a penetrating mechanism of injury, positive focused assessment with sonography for trauma (FAST) exam, heart rate ≥120, and systolic blood pressure ≤90 mmHg. Most trauma centers have developed their own massive transfusion protocol, which should be implemented immediately when massive transfusion is anticipated. This usually involves communicating with the laboratory and the transfusion service, as well as the immediate assessment of the prothrombin time (PT), partial thromboplastin time (PTT), platelets, fibrinogen, and hemoglobin levels. Thromboelastography also offers the ability for relatively rapid assessment of coagulation parameters when compared to the time required for traditional coagulation studies.