This is a real page turner and it's easy to see why it's the book that properly launched Crichton's career: it's full of detailed information about contemporary medicine but Crichton uses that detail to drive the plot, not to overwhelm the reader in minutiae (as some "techno thriller" writers do). Though this type of thriller has become a cilche now, I bet that it was rather refreshing at the time. Crichton's protagonist is a bit like the Dashiell Hammett version of a doctor. Yes, that's implausible, but Crichton makes it work well enough.
The biggest issue with the novel is how awfully dated it is in its attitude towards women: there are numerous lines that imply women are inferior to men both intellectually and morally - the worst of which, for me, is from a doctor character who believes that 90% of his female patients are imagining their conditions, which is about the most old man doctor thing to say ever. However, it's worth remembering that, given that this novel is in the first person, it would be inauthentic if the narrator wasn't a misogynist (and he's only relatively misogynist given everyone else's rampant misogyny).
If you can put aside the misogyny - or accept it as an accurate description of its time - this is an enjoyable read that I couldn't put down.