Mr. Patel is a 68-year-old, 90-kg male who underwent an exploratory laparotomy and lysis of adhesions 6 hours ago. You are on call and a nurse informs you that Mr. Patel’s blood pressure is 92/43 and his heart rate is 102. He is completely asymptomatic and says he feels “fine except for the tube in my nose.” You notice that his IVF bag is labeled “D5 0.45 normal saline” and is infusing at a rate of 125 mL/h.
2. What is the diagnosis of exclusion for all patients with postoperative hypotension?
Hypotension in the Immediate Postoperative Period
Postoperative hypotension is common and potentially serious, with a variety of underlying causes, including hypovolemia, cardiac failure, or sepsis. Because of the possibility of serious underlying pathology, the patient with postoperative hypotension should be rapidly evaluated and a diligent search for potentially life-threatening causes of hypotension should follow.
In general, a systolic blood pressure (SBP) less than 100 mm Hg or a mean arterial pressure (MAP) less than 65 mm Hg is considered hypotensive. That said, hypotension is best thought of as a decreased blood pressure rather than a low blood pressure—the difference between the patient’s current and baseline blood pressures is the most critical factor. For example, a blood pressure measurement of 95/43 mm Hg after an uncomplicated laparoscopic appendectomy in an otherwise healthy 25-year-old female whose SBP is normally no greater than 105 mm Hg is probably not hypotension. On the other hand, a blood pressure of 125/64 mm Hg after an uncomplicated laparoscopic appendectomy in a 65-year-old, homeless male who has had many years of untreated kidney disease and whose preoperative blood pressure was 212/103 mm Hg probably is hypotension. While the blood pressure reading of 125/64 mm Hg is “normal” in the conventional sense, the male patient’s tissues and peripheral vasculature have probably compensated for a long history of hypertension and therefore this blood pressure may be too low to provide adequate oxygen delivery to his tissues.
Evaluation of the hypotensive patient starts with urgently ruling out hemorrhage as a cause of the patient’s hypotension. If hemorrhage cannot be ruled out by history and physical exam, a workup including a CBC should be initiated while empiric treatment is begun.
For those patients in whom you suspect hemorrhage, proper management includes infusion of 1 L of 0.9 NS or LR. The patient’s blood pressure should respond soon after receiving the bolus, with an adequate response defined as a return to the patient’s baseline blood pressure and/or improvement in urine output. If the patient’s response is not adequate, a second 1 L bolus should be given, but suspicion for other, more life-threatening causes for the patient’s hypotension should be high and rapid escalation of care should be initiated. This would include notifying the senior ...