The metabolic stress response to trauma has been described as a progression through three phases: the ebb phase, the flow phase, and finally the recovery or resolution

Question

Define each of these and determine how they may correspond to this patient's hospital course.

Answer 1

Due to this patient's recent traumatic event, his metabolism was greatly affected. Not only was he experiencing a local stress due to the gunshot wound and various injuries, but he was also experiencing a systemic metabolic response. Critical illness, serious infection, severe injury, burns, or severe psychological stress can initiate this metabolic response. Metabolic stress encompasses three phases: the ebb phase, acute flow phase, and recovery phase or adaptive flow phase. The ebb phase occurs within the first 24-48 hours and is characterized by hemodynamic instability. There is a period of severe shock with depression of enzymatic activity and oxygen consumption, resulting in decreased cardiac output, decreased core temperature, and increased lactic acidosis. It is critical during this time to conduct fluid resuscitation and oxygen delivery. Thus, feeding this patient while he is still hemodynamically unstable is not a top priority for this stage. During the acute flow phase, which occurs from 3 to 10 days after initial stress event, the body is hypermetabolic with increased cardiac rate and oxygen consumption. There is also an increase in glucose production via gluconeogenesis (with resulting hyperglycemia), variable lipolysis, and increased protein breakdown for a gluconeogenic substrate. The body uses more amino acids from this muscle breakdown to create precursors for acute-phase proteins and glutamine for gut metabolism. This causes an increase in protein mobilization, increased urinary nitrogen excretion, and lean body mass wasting. During this acute flow phase, the body is activating its survival mechanisms to maintain organ systems and promote healing. Unfortunately, this also increases the risk for malnutrition and further complications including loss of lean body mass . The goal of this stage is to minimize catabolism. During the last stage of recovery/adaptive flow phase, the acute flow phase subsides and the initiation of recovery and repair processes begins. This results in a decrease in energy and protein needs due to the decrease in inflammation and catabolism, while anabolism begins to occur. This third phase can last up to one year after initial injury.
Based on the information we have about this patient, he was admitted with symptoms of shock and was hemorrhaging and then progressed into the flow phase, as indicated by his high metabolic needs of 3657 kcal/day. Also, we can see that the metabolic stress continued for at least 7 days as indicated by his labs. The labs that indicate inflammation—elevated WBC, elevated CRP, and low albumin. The results of his urinalysis also indicate a catabolic state as well as uncontrolled hyperglycemia as he was spilling ketones and glucose into his urine. The presence of edema is due to third spacing of intravascular fluids and due to severe hypoalbuminemia.