Intraoperative dexmedetomidine use is associated with lower incidence of acute kidney injury after non-cardiac surgery

Figures & data

Figure 1. Inclusion of study patients. Dex: Dexmedetomidine, 1:2 matching: propensity score matching.

Table 1. Baseline characteristics.

	Before matching			After matching
Variable	Control (n = 24317)	Dexmedetomidine (n = 2849)	p value	Control (n = 4552)	Dexmedetomidine (n = 2391)	p value
Demographics
Age, year	53.37 ± 14.43	53.72 ± 14.67	.217	53.23 ± 13.78	53.24 ± 14.17	.846
Male, %	47.1	52.5	<.001	47.2	46.8	.707
BMI (kg/m^2)	22.92 ± 3.58	23.31 ± 3.59	<.001	22.78 ± 2.98	22.98 ± 3.07	.078
Alcohol, %	5.2	2.5	<.001	5.8	2.7	<.001
Smoking, %	8.0	3.3	<.001	7.2	4.6	.006
Hypertension, %	21.3	20.5	.286	18.7	17.5	.231
Diabetes, %	12.4	11.3	.11	7.6	6.5	.13
Diuretics, %	2.1	0.7	<.001	1.8	0.8	<.001
ACEI/ARB, %	1.1	0.5	.002	0.6	0.5	.411
CCB, %	0.13	0.04	.283	0.1	0.5	.691
Pre-operative conditions
Hemoglobin, g/L	122.64 ± 22.69	125.23 ± 22.31	<.001	124.12 ± 22.33	125.01 ± 20.01	.021
Serum albumin, g/L	39.73 ± 5.53	39.90 ± 5.08	.121	39.88 ± 5.20	40.04 ± 5.00	.797
Pre-operation eGFR (mL/min)	97.62 ± 23.59	99.74 ± 20.85	<.001	97.55 ± 22.79	100.44 ± 20.79	<.001
Surgical data
ASA grade, %			<.001			<.001
1	5.7	5		6.02	5.47
2	55.3	54.9		57.14	57.34
3	33.8	37		32.27	34.63
4	5.2	3.2		4.57	2.55
Anesthesia method, %
General anesthesia, %	89.4	78.4	<.001	90.05	78.21	<.001
Non-general anesthesia, %	10.6	21.6	<.001	9.95	21.29	<.001
Amount of fluid infusion, (mL/24 hours)	2100 (1500–3100)	2100 (1500–3100)	.685	2100 (1500–3100)	2100 (1500–3100)	.352
Amount of fluid out (mL/24 hours)	500 (300–900)	600 (300–1000)	<.001	550 (300–909)	600 (300–1000)	<.001
Amount of blood loss, mL	150 (50–400)	200 (50–400)	.013	200 (50–400)	200 (50–400)	.984
Operative time, min	151 (103–220)	175 (120–253)	<.001	158 (105–224)	175 (120–250)	<.001
Lowest MAP, mmHg	61.29 ± 14.64	58.87 ± 17.03	<.001	61.42 ± 14.77	58.86 ± 16.82	<.001
Duration of hypotension, min	15 (10, 22)	17 (12, 25)	.442	15 (10, 21)	15 (11, 22)	.591
Vasoactive drugs, %	8.5	8.4	.729	7.7	7.9	.725
NSAIDS, %	24.1	18.8	<.001	25.13	19.41	<.001

Baseline characteristics of the patients who received Dexmedetomidine versus who did not before and after propensity score matching. ACEI: ACE inhibitors; AKI: acute kidney injury; ARB: angiotensin receptor blockers; ASA: American Society of Anesthesiologist; BMI: body mass index; CCB: calcium-channel blockers; eGFR: estimated glomerular filtration rate: MAP: mean arterial pressure. Vasoactive drugs include ephedrine and metaraminol: NSAIDs: Non-steroidal anti-inflammatory drugs; Parecoxib (40–80mg) or Flurbiprofen (50–100mg).

Table 2. Univariable analysis.

Variable	Statistics	Univariable OR (95% CI)	p value
Dexmedetomidine, %	2391 (34.44%)	0.60 (0.59, 0.81)	<0.001
Male, %	3268 (47.07%)	0.71 (0.55, 0.92)	0.010
Age, year	53.22 ± 13.91	1.02 (1.01, 1.03)	<0.001
BMI (kg/m^2)	22.99 ± 2.85	0.97 (0.92, 1.01)	0.1167
Alcohol, %	326 (4.70%)	0.89 (0.53, 1.48)	0.640
Smoking, %	487 (7.01%)	1.22 (0.77, 1.92)	0.394
Hypertension, %	1267 (18.25%)	1.74 (1.31, 2.31)	<0.001
Diabetes, %	501 (7.22)	2.11 (1.60, 2.77)	<0.001
Vasoactive drugs, %	538 (7.75%)	3.55 (2.73, 4.61)	<0.001
Diuretics, %	97 (1.40%)	5.56 (3.20, 9.65)	<0.001
ACEI, %	39 (0.56%)	1.44 (0.35, 6.03)	0.614
CCB, %	4 (0.06%)	0.00 (0.00, inf.)	0.969
Hb (g/L)	124.60 ± 22.27	0.98 (0.97, 0.98)	<0.001
Alb (g/L)	40.04 ± 5.13	0.89 (0.88, 0.92)	<0.001
Preoperation eGFR (mL/min)	98.55 ± 21.92	0.98 (0.97, 0.98)	<0.001
ASA, %
1	405 (5.83%)	1
2	3972 (57.21%)	1.62 (0.65, 4.03)	0.297
3	2297 (33.08%)	4.49 (1.82, 11.04)	<0.001
4	269 (3.87%)	16.07 (6.29, 41.07)	<0.001
General anesthesia, %	5981 (86.14%)	1.03 (0.71, 1.48)	0.885
Amount of fluid infusion (mL/24 h)	2100 (1500–3100)	1.00 (1.00, 1.00)	0.019
Amount of fluid out, mL	600 (300–900)	1.00 (1.00, 1.00)	0.180
Amount of blood loss (mL/24 h)	200 (50–400)	1.00 (1.00, 1.00)	<0.001
Operative time, min	165 (110–234)	1.00 (1.00, 1.00)	0.059
Lowest MAP, mmHg	60.54 ± 15.55	0.99 (0.98, 1.00)	0.067
Duration of hypotension, min	15 (10, 22)	0.99 (0.98, 1.00)	0.073
NSAIDs, %	1608 (23.16%)	0.64 (0.45, 0.90)	<0.001

Univariable analysis of AKI incidence. ACEI: ACE inhibitors; AKI: acute kidney injury; ARB: angiotensin receptor blockers; BMI: body mass index; CCB: calcium-channel blockers; ASA: American Society of Anesthesiologists; eGFR: estimate glomerular filtration rate.

Table 3. Multivariable regression analysis.

	Model 1	Model 2	Model 3	Model 4
	OR/β (95% CI) p value
AKI (OR)	0.60 (0.59, 0.81) <0.001	0.66 (0.49, 0.89) <0.001	0.68 (0.51, 0.92) 0.012	0.71 (0.52, 0.97) 0.034
AKI stages (β)	–0.02 (–0.03, −0.01) <0.001	–0.02 (–0.03, −0.00) <0.001	–0.02 (–0.03, −0.00) 0.009	–0.01 (–0.02, −0.00) 0.044

Multivariable regression analysis of AKI incidence. AKI stages (outcome of postoperative AKI was divided into four groups: stage 0, no AKI; stage 1, AKI grade 1; stage 2, AKI grade 2 and stage 3, AKI grade 3).

Model 1: non-adjusted.

Model 2: adjusted for age, sex, eGFR.

Model 3: model 2 plus hypertension, diabetes, diuretics.

Model 4: model 3 plus blood lossed, vasoactive drugs, Hb, Alb, amount of fluid infusion and out, operative time, ASA, lowest MAP and NSAIDs.

Table 4. Post-operation outcomes.

	Before matching			After matching
Out come	Control (n = 24,317)	Dexmedetomid ine (n = 2849)	p value	Control (n = 4552)	Dexmedetomidine (n = 2391)	p value
Post-operation eGFR (mL/min)	92.41 ± 21.30	97.24 ± 23.63	<.001	94.84 ± 21.41	97.84 ± 23.14	<.001
AKI,%	4.4	3.3	.008	4.2	2.6	<.001
AKI stages,%			.026			.003
0	95.61	96.67		95.83	97.45
1	3.98	2.98		3.76	2.30
2	0.22	0.28		0.20	0.21
3	0.19	0.07		0.21	0.04
ICU admission,%	4.68	4.73	.845	4.45	4.63	.872
Death (in hospital), %	0.63	0.62	.865	0.60	0.63	.625

Perioperative outcomes of the patients who received Dexmedetomidine versus who did not after propensity score matching. ICU, intensive care unit.

Table 5. Subgroup analysis of the association between postoperative AKI and Dexmedetomidine.

		Model 1	Model 2	Model 3	Model 4
AKI		OR (95% CI) p value
	Non-Dex		Dex
eGFR > 90 (mL/min), n = 4908	1	0.50 (0.33, 0.75) <0.001	0.49 (0.32, 0.74) <0.001	0.49 (0.33, 0.75) <0.001	0.51 (0.37, 0.79) 0.003
Blood loss < 1000 mL, n = 6384	1	0.62 (0.45, 0.86) 0.004	0.69 (0.50, 0.96) 0.029	0.70 (0.50, 0.98) 0.038	0.70 (0.50, 0.98) 0.039
NSAIDs = 0, n = 5335	1	0.57 (0.41, 0.78) <0.001	0.65 (0.47, 0.90) <0.001	0.67 (0.49, 0.93) 0.018	0.67 (0.48, 0.95) 0.027

The association between postoperative AKI and Dexmedetomidine in different subgroups. Dex, Dexmedetomidine.

AKI stages (outcome of postoperative AKI was divided into four groups: stage 0, no AKI; stage 1, AKI grade 1; stage 2, AKI grade 2 and stage 3, AKI grade 3).

Model 1: non-adjusted.

Model 2: adjusted for age, sex, eGFR.

Model 3: model 2 plus hypertension, diabetes, diuretics.

Model 4: model 3 plus blood lossed, vasoactive drugs, Hb, Alb, amount of fluid infusion and out, operative time, ASA, lowest MAP and NSAIDs.

Data availability statement

The raw data of experiments used to support the findings of this study are available from the corresponding author upon request.