Table 2.

Univariate analysis: procedure-related risk factors for postoperative hypothermia after brachial plexus block

Variable	Normothermia (n = 392)	Hypothermia (n = 268)	P
Approach of block			0.510
Interscalene	308 (78.6%)	221 (82.5%)
Supraclavicular	18 (4.6%)	12 (4.5%)
Infraclavicular	9 (2.3%)	3 (1.1%)
Axillary	57 (14.5%)	32 (11.9%)
BPB on left/right side	162/230	112/156	0.905
Type of surgery			< 0.001
Non-arthroscopic surgery	193 (49.2%)	91 (34.0%)
Arthroscopic shoulder surgery	199 (50.8%)	177 (66.0%)
Forced-air warmer	322 (82.1 %)	229 (85.4%)	0.261
Vasopressors
Phenylephrine	9 (2.3%)	13 (4.9%)	0.073
Ephedrine	37 (9.4%)	36 (13.4%)	0.108
Hypotensive agent (nicardipine)	34 (8.7%)	18 (6.7%)	0.359
Anticholinergics
Atropine	2 (0.5%)	3 (1.1%)	0.401
Glycopyrrolate	0 (0%)	1 (0.4%)	0.406
Analgesics
Fentanyl	211 (53.8%)	167 (62.3%)	0.030
Morphine	4 (1.0%)	4 (1.5%)	0.721
Pethidine	0 (0%)	2 (0.7%)	0.165
Fentanyl + morphine	1 (0.3%)	1 (0.4%)	> 0.999
Sedatives
Midazolam	115 (29.3%)	73 (27.2%)	0.558
Dexmedetomidine	80 (20.5%)	47 (17.5%)	0.350
Propofol	27 (6.9%)	17 (6.3%)	0.783
Midazolam + dexmedetomidine	94 (24.0%)	101 (37.7%)	< 0.001
Fluids, mL	300 [200-400]	300 [200-450]	0.001
Transfusion	0 (0%)	0 (0%)	NA
Estimated blood loss, mL	10 [5-15]	10 [5-15]	0.807
Duration of surgery, min	60 [45-85]	75 [55-95]	< 0.001

Values are presented as numbers, number (%), or median [interquartile ranges]. BPB, brachial plexus block; NA, not applicable.