Table 2.

Perioperative changes in sublingual total vessel density (TVD), small vessel density (SVD), and vessel density (VD) per study

Study	n	Technique	Study groups	Pre-CBP	CPB		Post-CPB
				Induction	Onset of CPB	Late phase of CPB	Post-CPB	ICU	24 h after surgery
Bienz et al. [28]	16	SDF	CABG	~ TVD	~ TVD	~ TVD	~ TVD	~ TVD	–
			CABG	~ SVD	~ SVD	↑ SVD	~ SVD	~ SVD	–
De Backer et al. [14]	9	OPS	Cardiac surgery with CPB	~ VD	~ VD	–	~ VD	~ VD	~ VD
Holmgaard et al. [21]	30	SDF	CABG with HMAP	–	~ TVD	–	~ TVD	–	–
			CABG with LMAP	–	~ TVD	–	~ TVD	–	–
Koning et al. [24]	33	SDF	CABG non pulsatile CPB	–	~ TVD	~ TVD	~ TVD	~ TVD	–
			CABG pulsatile CPB	–	~ TVD	~ TVD	~ TVD	~ TVD	–
Koning et al. [31]	13	SDF	CABG	–	↓ TVD	↓ TVD	↓ TVD	↓ TVD	–
Mohamed et al. [22]	70	SDF	CABG with regular anesthesia	–	~ TVD	–	~ TVD	–	–
			CABG dexmed anesthesia	–	~ TVD	–	↓ TVD	–	–
Özarslan et al. [20]	30	OPS	CABG sevoflurane anesthesia	~ TVD	↓ TVD	–	~ TVD	–	~ TVD
			CABG isoflurane anesthesia	~ TVD	↓ TVD	–	~ TVD	–	~ TVD
			CABG desflurane anesthesia	~ TVD	~ TVD	–	~ TVD	–	~ TVD
Prestes et al. [23]	22	SDF	CS with CPB	–	~ VD	~	~ TVD	–	–

A downward facing arrow (↓) represents a significant decrease compared to baseline measurement. An upward facing arrow (↑) represents a significant increase compare to baseline measurement. ~ represents no significant change compared to baseline value. TVD total vessel density, VD vessel density, SMD small vessel density, CPB cardiopulmonary bypass, SDF side-stream dark field imaging, OPS orthogonal polarization spectral imaging, n number of participants, h hours, CS cardiac surgery, CABG coronary artery bypass grafting, LMAP low mean arterial pressure, HMAP high mean arterial pressure