Microvascular response to transfusion in elective spine surgery

Table 1 Patient demographics

	Age (yr)	Height (cm)	Weight (kg)	BMI	Sex (m/f)
Mean (SD)	59.80 (10.96)	165.99 (9.83)	75.84 (15.75)	27.58 (5.45)	5/15

Table 2 Correlations with SmO₂

Variable	ρ(correlation)	No. of observations1
ScvO2	0.40704	92
SV	0.30967	8490
PvO2	0.20475	92
HCT	0.19402	89
CO	0.06498	8490
Lactate	0.0609	61
CI	0.05839	8490
pH A	0.0578	92
SVV	-0.10652	8490
RBC	-0.25085	18
Cell saver	-0.37471	37
Albumin	-0.42714	29

¹Eight thousand four hundred and ninety total observations within 20 patients (not all hemodynamic parameters were examined at each observation).

Table 3 SmO₂ statistics for individual patients and overall

Patient	No. of observations (time counts)	SmO2 statistics
		Mean	Std Dev	Minimum	Maximum
1	1609	47.30205	4.231185	39.24457	59.81775
2	261	54.48111	4.559080	41.36314	60.91571
3	110	58.08155	3.474810	49.92571	63.56974
4	1061	59.45269	5.814339	42.39521	67.48903
5	333	59.86487	6.765487	43.87553	70.40168
6	284	60.44015	2.490064	53.33939	68.04648
7	486	60.78656	13.90398	30.77515	75.79442
8	1440	60.95438	4.090378	48.86891	73.39652
9	420	61.17271	2.276567	54.89989	65.64407
10	1470	61.18899	2.880967	52.65419	69.78379
11	203	61.95770	3.067270	47.69575	71.06789
Total	7677	57.63074	7.677996	30.77515	75.79442

Sorted by mean SmO₂.