Pelvic fractures and long bone fractures

Damage control resuscitation

The most common manifestation of pelvic and long bone fracture in the intensive care unit (ICU) is hemorrhage. It is well established that severely injured trauma patients arrive at the hospital with coagulopathy already present, and this is an independent predictor of mortality. ^, The development of coagulopathy is a multifactorial process, theorized to stem from humoral activation of the coagulation cascade with consumption, systemic inflammation, and fibrinolysis. Acquired traumatic coagulopathy develops independent of resuscitation strategy, but it is believed that subsequent resuscitation with crystalloid or packed red cells alone further exacerbates coagulopathy. Therefore management of hemorrhagic shock from trauma has shifted from liberal administration of early crystalloid and red blood cells (RBCs) to the concept of “damage control resuscitation,” or balanced resuscitation with more plasma and platelet administration.

Early data from military and civilian trauma centers demonstrates that increased plasma:RBC ratios are associated with survival to hospital discharge. ^, Subsequent clinical trials have validated the use of balanced resuscitation strategies on mortality and hemostasis in multitrauma patients. The Prospective, Observational, Multicenter, Major Trauma Transfusion study (PROMMTT) is a landmark study that demonstrated reduced mortality with early administration of plasma and platelets and higher plasma:platelet:RBC ratios in the early resuscitation period. Further, the Pragmatic, Randomized Optimal Platelet and Plasma Ratios trial (PROPPR) assessed the efficacy of a 1:1:1 ratio of blood product administration vs. a 1:1:2 ratio; the trial found no difference in mortality between these two groups at 24 hours or 30 days, but did find increased hemostasis and less death because of hemorrhage. Importantly, there was also no difference in rates of acute respiratory distress syndrome, multiple organ failure, venous thromboembolism, sepsis, or transfusion-associated complications. Overall, damage control resuscitation with a 1:1:1 ratio of platelets:plasma:RBC administration in patients suffering hemorrhagic shock decreased mortality and overall volume of resuscitation and has become the accepted standard for the resuscitation of trauma patients. Further resuscitation in the ICU consists of correction of coagulopathy as needed, with the aid of coagulation studies or viscoelastic testing if available.

Another factor to consider during damage control resuscitation is the presence of hyperfibrinolysis. Initially, there was much excitement over the use of tranexamic acid (TXA)—an antifibrinolytic agent—because of the Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage 2 (CRASH-2) study. This study examined adult trauma patients with hemorrhagic shock and found reduced mortality with administration of TXA within 3 hours. ^, A subgroup analysis of the PROPPR trial also showed improved 6-hour mortality in patients with hyperfibrinolysis on admission who were given TXA without an increase in venous thromboembolism. However, there have been conflicting data regarding dosing TXA universally in trauma patients with hemorrhagic shock, with evidence that there may be an increase in mortality and venous thromboembolic phenomenon in a subset of patients who required operative intervention and presented early to a level 1 trauma center. ^, It also appears late administration of TXA offers no mortality benefit compared with administration within 3 hours of injury. Viscoelastic testing, such as thromboelastography if available, may help stratify hemorrhaging patients into those that do and do not have hyperfibrinolysis based on the LY30 value. LY30 greater than 3% identifies hyperfibrinolysis, and this patient population appears to benefit from TXA administration. ^, The use of TXA and thromboelastography in trauma, however, is controversial; at present both are tools available to the ICU physician and must be used based on clinical judgment while more research is performed.

Open fractures

Whether a fracture is open or closed is an important distinction and should be a component of the initial assessment of any fracture. There are significant implications on the risk of wound infections, osteomyelitis, fracture nonunion, morbidity, and mortality depending on the presence of an open fracture and the degree of contamination. An open fracture is defined as any fracture with an overlying soft tissue defect that tracks to the fracture site. Open fractures can be further subclassified into grades, with higher grades associated with increased infectious complications and mortality. Broadly, grade I and II involve simple, clean lacerations without a crushing component or degloving injury, whereas grade III fractures involve much more complex and contaminated wounds and special cases such as farming accidents or arterial injury requiring surgical intervention. Infections typically involve gram-negative rods and gram-positive cocci. Though multidrug-resistant organisms have been implicated in some outbreaks of open fracture infections in the hospital, this is relatively uncommon and not prevented by broader prophylactic antibiotic coverage. Antibiotics should be started within 3 hours of presentation. The use of a first-generation cephalosporin (e.g., cefazolin—or clindamycin if anaphylactic to penicillin) for 48–72 hours is adequate antibiotic prophylaxis for grade I–II fractures, and an aminoglycoside should be added for grade III fractures. In farm-related accidents, penicillin G or clindamycin should be added to the antibiotic regimen because of the higher risk of infection by Clostridium species. In addition to antibiotics, open fractures require early operative exploration to wash out the tissues, stabilize the fracture, and cover the fracture with soft tissue to reduce the risk of infection.

Nutrition

After severe injury, patients frequently enter a state of hypermetabolism that progresses to catabolism that progresses rapidly to malnutrition. When evaluating all geriatric patients with hip fractures, an increasingly common patient population both in and out of the ICU, there is a significant practice pattern variation with regard to nutritional supplementation. Specifically, there is a tendency to underfeed this population. Underfeeding occurs despite evidence that in that patient population, malnutrition increases mortality, whereas adequate nutrition supplementation leads to greater functional recovery. When evaluating the subset of critically ill trauma patients, inadequate nutrition has been shown to increase morbidity and mortality. Early enteral nutrition has been shown to have numerous benefits in the ICU setting. It promotes gut mucosal integrity, motility, and immunity and reduces nosocomial infections. Furthermore, in trauma patients specifically, early enteral nutrition has clearly been shown to decrease mortality. If enteral nutrition cannot be administered, parenteral nutrition should be considered. A recent meta-analysis by the Cochrane Collaboration demonstrated no difference between enteral and parenteral routes with regard to mortality, aspiration, and pneumonia, although the enteral route may be associated with decreased incidence of sepsis. ^,

The 2016 American Society for Parenteral and Enteral Nutrition Guidelines (ASPEN) and the 2019 European Society guidelines recommend early initiation of enteral feeding (i.e., within 24–48 hours), provided the patient does not have any known bowel injury and is hemodynamically stable. ^, The ASPEN guidelines recommend administration of immune-modulating formulas containing arginine and glutamine in the trauma population because of decreased infection rates. These enteral formulas can be used in patients with open abdomens as well, provided they have intestinal continuity. Protein delivery is an especially important element of nutrition supplementation in this population; multitrauma patients will be on the upper end of the 1.2–2 g/kg/day protein that is recommended in the ICU. If enteral nutrition cannot be safely provided, or if it will not be able to meet the caloric needs of the patient, then parenteral nutrition should be initiated early in this high-risk population. Current guidelines recommend hypocaloric parenteral feeding initially at 80% basal energy expenditure, or <20 kcal/kg/day, while still maintaining adequate protein feeding at 1.2–2 g/kg/day, increasing gradually to cover full basal energy expenditure with frequent clinical reassessment. A full discussion regarding nutrition for ICU and trauma patients is outside of the scope of this chapter.