Chapter 19-1: Approach to the Patient with GI Bleeding - Case 1

CHIEF COMPLAINT

CONSTRUCTING A DIFFERENTIAL DIAGNOSIS

The approach to GI bleeding is similar to the approach to other potentially life-threatening illnesses. Patient stabilization, specifically, hemodynamic stabilization is the first step in management. In a patient with significant GI bleeding, management precedes diagnosis, usually made by colonoscopy or esophagogastroduodenoscopy (EGD). The pivotal point in the differential, post stabilization, is distinguishing between an upper or lower GI source for blood loss. From there, by using severity of the bleed, patient demographics and assessing risk factors for bleeding sources, one can narrow down the differential further.

Initial management follows a regimented course. First, the patient must have a risk assessment for the severity of bleeding and preparation must be made for resuscitation if further bleeding occurs. This is followed by hemodynamic stabilization and completion of initial diagnostic and therapeutic testing.

1. Risk assessment

   1. The best risk assessment tool for upper GI bleed is the Glasgow-Blatchford Score.

      1. The score includes variables such as blood urea nitrogen (BUN), hemoglobin, blood pressure, heart rate.

      2. Low scores identify low-risk patients who potentially can be treated as an outpatient.

      3. A score of 0 has LR– of 0.02 for need for urgent endoscopic intervention equating to a very low-risk patient.

   2. For lower GI bleeding, the following patient factors predict poor outcomes (increased risk of mortality, adverse outcomes or re-bleeding):

      1. Initial hematocrit < 35%; OR 6.3

      2. Age > 60; OR 4.2

      3. Gross blood on rectal exam; OR 3.9

      4. Heart rate > 100 bpm; OR 3.7

      5. Systolic pressure blood pressure < 100 mm Hg; OR 3.0

2. Preparation for hemodynamic stabilization, resuscitation, and further bleeding

   1. All patients should have their blood typed and be cross-matched for at least 2 units of packed red blood cells.

   2. Two large bore IVs

      1. IVs should be ≤ 16 gauge.

      2. Because flow = ΔP (πr⁴/8μL) (where ΔP is the pressure differential, r is the radius of the IV, μ is the viscosity of the fluid, and L is the length of the IV), flow can be maximized by

         1. Increasing the pressure behind the fluid being infused (squeezing the bag).

         2. Decreasing the length of the IV.

         3. Increasing the gauge of the IV (the most effective as the flow goes up by the fourth power of any increase).

      3. Large gauge IVs (16 and larger) are much more effective than central lines for volume resuscitation.

         Always make sure your patient has 2 usable large bore IVs, so you do not have to worry about IV access should life-threatening bleeding develop.

      4. In the setting of severe hemorrhage, a urinary catheter, with regular monitoring of urinary output, helps monitor the adequacy of volume resuscitation.

3. Hemodynamic stabilization

   1. Clinically assess volume status.

      1. Signs of shock ...