Decreased reflection coefficient as a possible cause of low blood pressure in severe septicaemia.

A 44-year-old woman developed a septicaemia with low intra-arterially recorded blood pressure values despite vasoactive medication and optimal support. Sphygmomanometer cuff measurements showed higher values than intra-arterial blood pressure records. We suggest a low reflection coefficient of the capillary bed as the cause of this phenomenon. The constant pressure of the sphygmomanometer cuff on the venous tract appeared to create an increase of the reflection coefficient in our patient, thus causing higher blood pressure readings with the sphygmomanometer cuff measurements than expected.