Table 2.

Intraoperative invasive Hb results

	SpHb monitoring group	Standard care group	p
PPV of a decrease in CoOxHb > 1 g/dl	93.3%	54.5%	0.002
PPV of CoOxHb falling to 10 g/dl	86.7%	50.0%	0.015
CoOxHb < 7 g/dl, n	0	1

Data are expressed as percentages or numbers of patients. PPVs were compared using Fisher’s exact test. PPV positive predictive value