Autonomic nervous system activity and the risk of nosocomial infection in critically ill patients with brain injury

Intensive Care Medicine Experimental

Table 3 Admission HRV parameters

HRV parameter	Infected (n = 9)	Not infected (n = 19)	p-value
LF (msec², median, IQR)	53 (5–121)	117 (58–339)	0.029
HF (msec², median, IQR)	72 (27–90)	72 (22–177)	0.572
TP (msec², median, IQR)	349 (97–750)	353 (247–1218)	0.446
LF:HF ratio (median, IQR)	0.93 (0.43–2.45)	1.82 (1.33–4.36)	0.065
LFnu (mean, SD)	0.46 (0.24)	0.64 (0.18)	0.033
HFnu (mean, SD)	0.54 (0.24)	0.36 (0.18)	0.033

Data are presented as mean and SD or as median and IQR
LF low frequency, HF high frequency, TP total power, LF:HF ratio ratio between low and high frequency, LFnu normalized units of low-frequency power, HFnu normalized units of high-frequency power