Treatment • The Blood Project

The patient had worsening mental status in the Emergency Department. She was intubated for airway protection and admitted to the medical intensive care unit. She did not require pressor support. Her urine output, urea and creatinine improved with fluids.

What are treatment options for her hematological status when first admitted?

a

Red cell transfusion

She was transfused with 4 units of packed red blood cells. Her Hb increased from 2.0 to 7.0 g/dL.

b

Intravenous iron

c

DDAVP

d

Tranexamic acid

Not unreasonable if she is believed to be actively bleeding.

Let’s return to the concept of critical oxygen delivery. Recall the plot of oxygen delivery against oxygen consumption. Our patient, even with the most efficient of cardiovascular adaptations, will be squarely on the supply-dependent part of the curve. This means that any further reduction in oxygen delivery will lead to anaerobic metabolism and increased lactic acid production.

When DO2 is higher than a threshold value, VO₂ remains stable (O₂ supply independency) because the O₂ extraction rate of oxygen (EO2=VO2/DO2) changes proportionally. When DO₂ falls below this threshold, a proportional increase in VO₂ cannot be maintained, and the VO₂ linearly drops to zero (O₂ supply dependency). The inflection point between the two slopes is accepted as indicating the critical level of DO2. The O2 supply dependency is associated with an increase in blood lactate concentration denoting possible activation of the anaerobic pathway. The anaerobic threshold and associated DO2 (crit) values will vary substantially with metabolic rate, some disease states and perhaps such complex factors as a patient’s age or genetic make-up. The curve is shifted to the right in patients with critical illness because of impaired oxygen extraction.

The surest way to offset this risk is to transfuse the patient. However, some patients, such as Jehovah Witnesses, do not accept blood transfusions. How would you manage a case such as this without transfusion support (see next slide for answer)?

There are several possible non-transfusion interventions:

Use sedation and/or neuromuscular block to minimize oxygen demand.
Administer hematinic agents, for example IV iron in a case of iron deficiency.
Administer erythropoietin.
Deliver high oxygen concentration or use hyperbaric oxygen therapy to increase the level of plasma-dissolved oxygen.
Investigational therapeutics such as artificial oxygen carriers.

Additional history from the patient’s family confirmed that the patient had experienced years long history of chronic abnormal uterine bleeding. A CTAP showed massively enlarged uterus measuring 17.8 x 12.0 x 15.4 cm, which was hyperenhancing and concerning for malignancy:

She ultimately had a EXPLORATORY LAPAROTOMY, TOTAL ABOMINAL HYSTERECTOMY, BILATERAL SALPINGO-OOPHORECTOMY, LYMPH NODE BIOPSY, which showed the following:

Thus, the diagnosis was fibroids.