[BostonCard]

A friend of mine, a nurse, swore early that it would basically be impossible. (They train nurses to draw blood away from the fingertip because it's much more reliable, as I understand it.) I believed her but didn't take her seriously enough to write about it. Probably should've, in retrospect. 

There are differences between capillary blood labs (as would result from a fingerstick) and venous blood labs (as would result from a traditional draw).  These differences aren't so large that you can't, for example, reliably measure glucose from a fingerstick.  

Nurses are trained to draw blood from veins.  Veins generally get larger and thus easier to cannulate as they merge and get closer to the heart.  A highly trained nurse can somehow manage to draw blood from a stone, blindfolded.  An ICU doctor like myself; we have to go after the jugular vein to get blood.

I think the challenge for Theranos wasn't physiological; it was an engineering challenge.  At low volumes, blood, which is already more viscous than water, becomes a fluid dynamics nightmare.  A friend of mine who was a chemical engineer at Stanford interviewed with them and came away thinking that their proposed solution was a dead end.  It was an approach that had been tried many times unsuccessfully in the past.  He came away thinking the company was stubborn and full of hubris, and halfway through the interview, figuring he didn't want to work there anyways, candidly told them that their approach was a dead end.

BC

[BostonCard]

A friend of mine, a nurse, swore early that it would basically be impossible. (They train nurses to draw blood away from the fingertip because it's much more reliable, as I understand it.) I believed her but didn't take her seriously enough to write about it. Probably should've, in retrospect. 

There are differences between capillary blood labs (as would result from a fingerstick) and venous blood labs (as would result from a traditional draw).  These differences aren't so large that you can't, for example, reliably measure glucose from a fingerstick.  

Nurses are trained to draw blood from veins.  Veins generally get larger and thus easier to cannulate as they merge and get closer to the heart.  A highly trained nurse can somehow manage to draw blood from a stone, blindfolded.  An ICU doctor like myself; we have to go after the jugular vein to get blood.

I think the challenge for Theranos wasn't physiological; it was an engineering challenge.  At low volumes, blood, which is already more viscous than water, becomes a fluid dynamics nightmare.  A friend of mine who was a chemical engineer at Stanford interviewed with them and came away thinking that their proposed solution was a dead end.  It was an approach that had been tried many times unsuccessfully in the past.  He came away thinking the company was stubborn and full of hubris, and halfway through the interview, figuring he didn't want to work there anyways, candidly told them that their approach was a dead end.

BC