Potential Impact of Local Anesthetics Inducing Granulocyte Arrest and Altering Immune Functions on Perioperative Outcome

Figures & data

Table 1 Characteristics of the Study Population

Characteristics	Value
Number of subjects	17
Gender (female/male)	8/9
Age [years]	27 [22–63]
Height [cm]	172 [161–191]
Weight [kg]	76 [37–91]
BMI [kg/m^2]	26 [21–29]

Note: Mean values and [range].

Figure 1 ROS production (T_maxROS) and NETosis (ET₅₀NET) visualized by time-related total surface areas.

Table 2 Descriptive Statistics of TL in the First 30 Minutes with Either Bupivacaine or Lidocaine Treatment

Bupivacaine [mmol/L]	Median TL [µm]	IQR	Relative Reduction to Control [%]	Lidocaine [mmol/L]	Median TL [µm]	IQR	Relative Reduction to Control [%]
Control	278	225	–	0	278	225	–
0.03	226	309	81.3 *	0.007	385	259	138 *
0.09	236	252	84.9 *	0.14	357	221	128 *
0.16	239	308	86.0 *	0.71	328	243	118 *
0.32	102	206	36.7 *	1.42	329	273	118 *
0.63	77	197	27.7 *	3.55	0	0	0 *
0.95	50	75	18.0 *	7.1	0	0	0 *
1.58	0	0	0 *	14.21	0	0	0 *
3.16	0	0	0 *

Note: Asterisks (*) mark significant changes compared to the control group (see text for further details).

Figure 2 Track Length [µm] during the first three 30-minute time periods clustered by increasing concentrations of bupivacaine. Higher concentrations resulted in complete migration arrest and are not shown in the figure. *Depicts extreme values and ^oIndicates outliers.

Figure 3 Track length [µm] during the first three 30-minute time periods clustered by increasing concentrations of lidocaine. Lidocaine concentrations above 1.42 mmol/L induced an immediate arrest of PMNs and are therefore not shown in the figure. ^oIndicates outliers.

Table 3 Summary of T_maxROS and ET₅₀NET Changes Under LA Impact

LA	LA-Concentration [mmol/L]	TmaxROS [min] Median ± SD	ET50NET [min] Median ± SD
Bupivacaine	0	115.5 ± 46.0	320.4 ± 47.5
	0.03	101.6 ± 12.2	349.7 ± 31.4
	0.09	81.47 ± 21.64	338.6 ± 35.6
	0.16	88.5 ± 34.4	296.2 ± 34.0
	0.32	164.4 ± 34.8	314.6 ± 12.4
	0.63	70.5 ± 16.9	319.3 ± 39.0
	0.95		229.8 ± 37.4
	1.58		107.3 ± 29.3
	3.2		83.0 ± 6.11
Lidocaine	0	115.5 ± 46.0
	0.007	110.5 ± 24.8	355.8 ± 10.2
	0.14	106.6 ± 6.1	356.3 ± 5.81
	0.71	102.5 ± 21.5	428.9 ± 13.8
	1.42	100.9 ± 17.2	392.0 ± 50.7
	3.55	143.7 ± 38.0	343.9 ± 26.9
	7.1	101.7 ± 35.7	240.7 ± 23.7
	14.21		49.0 ± 18.8

Figure 4 Fitted curves of the LA dependent concentrations – ET50 connection indicating the induction of NETosis of human granulocytes by bupivacaine and lidocaine.

Table 4 Results of Flow-Cytometric Detection on Cell-Surface Antigen Expression [Median Fluorescence Intensities. Ranges in Brackets]

Cell-Surface Antigen	MFI of Control Group	MFI Including All Concentrations of Bupivacaine	MFI Including All Concentrations of Lidocaine
CD11b	569(3–1244)	560(126–1147)	620(386–1020)
CD62L	118(2–328)	142(62–328)	118(81–217)
CD66b	107(2–209)	106(10–337)	140(65–233)

Table 5 Summary of LA Effects on PMNs in Our in vitro Study

Local Anesthetic	Bupivacaine		Lidocaine
Concentration Range	Low (~0.01 mM)	High (max. 15 mM)	Low (~0.02 mM)	High (max. 17 mM)
Clinical Location	Intravascular	Extravascular	Intravascular	Extravascular
Effect on PMNs
Viability	↔	↔	↔	↔
CD66b (“Activation”)	↔	↔	↔	↔
CD62L or CD11b (“Adhesion”)	↔	↔	↔	↔
Chemotactic migration	↔	↓↓↓	↑	↓↓↓
Induction period of ROS-production	↔	↓↓↓	↔	↓↓↓
Intensity of ROS-production	↔	↔	↔	↔
Duration until NETosis-Onset	↓	↓↓↓	↑	↓↓↓

Note: ↔ indicates no change, ↑/↓ indicates slight increase or decrease and ↓↓↓ indicates strong decrease.