Cardiac index

A co-worker has a patient who needs home inotropic therapy.  Based on her paperwork and in speaking to her physician, the patient has a cardiac index of 0.36.  Is this possible?  Can a person survive with an index this low?  The patient is currently on a Dobutamine gtt at 5mcg/kg/min continuously.  What is the lowest cardiac index sustainable for life?  The lowest I have personally seen is 1.2.  I know the normal range is 2.4-4.2 or so.

I would appreciate your input because I have been unable to find anything online regarding the lowest CI possible.

Thanks.

[Dr_Veena]

Hi,
      Cardiac index is a measure of cardiac output in relation to the body surface area. This gives a idea of the performance of the heart in relation to the size of the individual. Normal value lies between 2.6 - 4.2 L/min per square meter. A value of less than 1.8L/min/m2 suggests of cardiogenic shock. As, you mentioned that the patient is on inotropic support, the need for this should be known to assess the status of the patient. 0.36 is a very low value of cardiac index, but not equal to zero. Hence, some amount of cardiac activity is present, which with inotropic support and other measures is to be improved. Hope this helps. Best.