Development of Cardiovascular Indices of Acute Pain Responding in Infants: A Systematic Review

Table 7

Mean and standard deviations for low frequency/high frequency ratio in response to acute pain at less than 7 postnatal days.

Gestational age	Reference	Mean LF/HF ratio	SD
28–32 weeks	Cong et al. [39]	1.75	1.84
37–42 weeks	Oberlander et al. [57]	6.00	N/A
	Weissman et al. [71]	6.1	3.2

Note. LF = low frequency, HF = high frequency, SD = standard deviation, and denotes numbers that were extrapolated from graphs.