Association between anesthesia technique and complications after hip surgery in the elderly population

Table 1 Baseline characteristics of all patients

	Total (n = 718)		Spinal anaesthesia (n = 579)		General anaesthesia (n = 139)		Standardised difference	P value
	n/mean	%/SD	n/mean	%/SD	n/mean	%/SD
Age (yr)1	84.76	5.38	85.23	5.33	82.82	5.15	-0.529	< 0.001
Sex							-0.023	0.521
Female	532	74.1	426	73.6	106	76.3
Male	186	25.9	153	26.4	33	23.7
ASA1 classification							-0.322	< 0.001
1	0	0	0	0	0	0
2	85	11.8	56	9.7	29	20.97
3	575	80.1	473	81.7	102	73.4
4	55	7.7	47	8.1	8	5.8
5	0	0	0	0	0	0
Position type1							-0.619	< 0.001
Lateral decubitus position	282	39.3	199	34.5	83	59.7
Prone position	9	1.3	8	1.4	1	0.7
Supine position	134	18.7	106	18.4	28	20.1
Traction position	285	39.7	258	44.8	27	19.4
Others	5	0.7	5	0.9	0	0
Operation time (min)1	69.80	35.34	67.10	31.47	80.98	46.70	0.322	0.001
Anaesthesia time (min)1	117.48	45.84	113.13	42.50	135.54	54.22	0.458	< 0.001
Blood loss (mL)1	68.85	82.86	60.71	61.96	102.55	134.55	0.402	< 0.001
NNIS1							-0.292	< 0.001
0	214	29.8	155	26.8	59	42.4
1	496	69.1	420	72.5	76	54.7
2	8	1.1	4	0.7	4	2.9
CCI1	5.14	1.47	5.23	1.48	4.77	1.41	-0.368	0.001
Comorbidities
Respiratory system	88	12.3	77	13.3	11	7.9	-0.265	0.085
Circulatory system	533	74.2	429	74.1	104	74.8	0.027	0.914
Digestive system	91	12.7	72	12.4	19	13.7	0.069	0.695
Urogenital system	67	9.3	56	9.7	11	7.9	-0.008	0.627
Blood system	20	2.8	14	2.4	6	4.3	0.098	0.248
Endocrine system	207	28.8	167	28.8	40	28.8	-0.000	1.000
Autoimmune system	7	1	5	0.9	2	1.4	-0.020	0.626
Nervous system	20	2.8	14	2.4	6	4.3	0.067	0.248
Cerebrovascular system	193	26.9	162	28	31	22.3	-0.108	0.201
Facial features	8	1.1	7	1.2	1	0.7	-0.020	1.000
Mental disorders	10	1.4	9	1.6	1	0.7	-0.073	0.696
Osteoporosis	13	1.8	10	1.7	3	2.2	0.031	0.724
Tumour	62	8.6	51	8.8	11	7.9	-0.001	0.744
Operation	272	37.9	216	37.3	56	40.3	0.035	0.559
Blood transfusion	26	3.6	20	3.5	6	4.3	0.015	0.801
Laboratory examination
Urea	7.71	6.18	7.78	6.05	7.43	6.71	-0.039	0.581
Creatinine1	90.13	66.24	91.95	71.04	82.40	39.20	-0.161	0.049
e-GFR	64.82	21.16	64.07	21.36	67.96	20.07	0.194	0.075

¹P < 0.05. ASA: American Society of Anaesthesiologists; CCI: Comprehensive complication index; eGFR: Estimated glomerular filtration rate; NNIS: National nosocomial infection surveillance.

Table 2 Baseline characteristics in propensity score-matched cohorts

	Total (n = 309)		Spinal anaesthesia (n = 206)		General anaesthesia (n = 103)		Standardised difference	P value
	n/mean	%/SD	n/mean	%/SD	n/mean	%/SD
Age (yr)	84.23	5.12	84.33	5.21	84.04	4.95	-0.128	0.644
Sex							-0.021	0.401
Female	239	77.3	158	76.7	81	78.6
Male	70	22.7	48	23.3	22	21.4
ASA classification							-0.117	0.873
1	0	0	0	0	0	0
2	33	10.7	20	9.7	13	12.6
3	260	84.1	178	86.4	82	79.6
4	16	5.2	8	3.9	8	7.8
5	0	0	0	0	0	0
Position type							-0.114	0.261
Lateral decubitus position	150	48.5	95	46.1	55	53.4
Prone position	5	1.6	4	1.9	1	1.0
Supine position	56	18.1	34	16.5	22	21.4
Traction position	97	31.4	72	35	25	24.3
Others	1	0.3	1	0.5	0	0
Operation time (min)	76.10	33.1	77.23	31.90	73.81	35.50	-0.033	0.391
Anaesthesia time (min)	125.05	39.8	124.31	38.84	126.41	41.94	-0.034	0.672
Blood loss (mL)	75.71	67.0	72.48	62.96	82.18	74.22	-0.032	0.230
NNIS							0.050	0.635
0	40	12.9	6	29.6	34	33
1	213	68.9	143	69.4	67	65
2	4	1.3	2	1.0	2	1.9
CCI	5.05	1.4	5.09	1.39	4.97	1.39	0.033	0.470
Comorbidities
Respiratory system	37	12.0	28	13.6	9	8.7	0.062	0.266
Circulatory system	232	70.1	153	74.3	79	76.7	0.026	0.678
Digestive system	40	12.9	24	11.7	16	15.5	-0.046	0.370
Urogenital system	26	8.4	18	8.7	8	7.8	0.055	0.832
Blood system	10	3.2	6	2.9		3.9	-0.025	0.736
Endocrine system	83	26.9	55	26.7	28	27.2	-0.025	1.000
Autoimmune system	3	1.0	2	1.0	1	1.0	0.024	1.000
Nervous system	9	2.9	5	2.4	4	3.9	0.014	0.488
Cerebrovascular system	80	25.9	55	26.7	25	24.3	0.079	0.681
Facial features	4	1.3	3	1.5	1	1.0	0.047	1.000
Mental disorders	3	1.0	2	1.0	1	1.0	0.062	1.000
Osteoporosis	8	2.6	6	2.9	2	1.9	0.076	0.723
Tumour	23	7.4	14	6.8	9	8.7	0.008	0.646
Operation	117	37.9	77	37.4	40	38.8	0.189	0.901
Blood transfusion	14	4.5	8	3.9	6	5.8	-0.220	0.562
Laboratory examination
Urea	7.30	4.8	7.49	5.43	6.90	3.27	0.060	0.360
Creatinine	8.64	65.4	91.85	76.31	81.92	31.79	0.018	0.143
e-GFR	64.45	21.2	63.5	21.69	66.37	20.24	-0.036	0.313

ASA: American Society of Anaesthesiologists; CCI: Comprehensive complication index; e-GFR: Estimated glomerular filtration rate. NNIS: National nosocomial infection surveillance.

Table 3 Types of complications

	Spinal anaesthesia (n = 206)		General anaesthesia (n = 103)		P value
	n	%	n	%
Hip joint dysfunction	14	6.8	3	2.9	0.159
Deep vein thrombosis	3	1.5	0	0.0	0.219
Delirium	9	4.4	3	2.9	0.532
Pneumonia	25	12.1	7	6.8	0.147
Shock	2	1.0	1	1.0	1.000

Table 4 Primary and secondary outcomes

	Spinal anaesthesia (n = 206)		General anaesthesia (n = 103)		P value
	n/mean	%/SD	n/mean	%/SD
Length of hospital stay (d)	12.54	4.58	13.31	5.05	0.212
90-d readmission	20	9.7	11	10.7	0.789
Clavien-Dindo score					0.583
1	126	61.2	65	63.1
2	69	33.5	30	29.1
3	1	0.5	0	0
4	10	4.9	8	7.8
5	0	0	0	0
Renal function
GLU (mmoL l-1)1	8.06	2.77	7.40	2.36	0.006
Urea (mmoL l-1)	7.34	3.27	7.46	3.73	0.943
Cr (μmoL l-1)	92.43	59.39	83.47	36.25	0.822
eGFR (mL min-1/1.73 m2)	63.87	21.54	65.67	20.54	0.656
ALB (g)	31.28	3.28	32.01	3.92	0.148
Routine blood
WBC (109 l-1)1	10.76	3.16	10.00	2.77	0.033
NEUT (%)	82.41	6.08	81.38	6.16	0.170
RBC (1012 l-1)	3.31	0.55	3.84	5.57	0.753
Hb (g l-1)	95.07	15.17	95.98	15.41	0.624
HCT (%)	29.15	4.84	29.60	4.71	0.437
PLT (109 l-1)	234.14	110.26	225.33	88.61	0.486
PCT (%)	0.33	0.40	0.19	0.15	0.187
Coagulation
PT (s)	14.02	1.20	14.48	1.99	0.233
PT% (%)	88.54	11.54	85.59	16.74	0.170
INR (R)	1.09	0.09	1.13	0.20	0.420
FIB (g l-1)1	5.10	1.11	4.70	1.26	0.029
APTT (s)	40.04	5.34	40.04	5.86	0.925
DDi (ng l-1 FEU)1	5.9	4.07	4.25	3.98	0.003
Others
TnT (μg l-1)	28.08	280.69	2.54	2.94	0.521
BNP (pg m l-1)1	187.98	286.26	340.96	457.10	0.009
NTProBNP (pg m l-1)	1250.66	1361.23	1067.31	1920.33	0.233
hsCRP (mg l-1)1	84.71	46.71	60.39	40.72	0.002
ERS (mm h-1)	52.78	29.49	51.21	69.59	0.214

¹P < 0.05. GLU: Glucose; CRE: Creatinine; eGFR: Estimated glomerular filtration rate; ALB: Albumin; WBC: White blood cell; NEUT: Neutrophil; RBC: Red blood cell; Hb: Haemoglobin; HCT: Haematocrit; PLT: Platelet; PT: Prothrombin time; INR: International Normalised Ratio; FIB: Fibrinogen; APTT: Activated partial thromboplastin time; DDi: D-Dimer; TnT: Troponin T; BNP: Brain natriuretic peptide; NTProBNP: N-terminal pro brain natriuretic peptide; hsCRP: Highly sensitive C-reactive protein; ESR: Erythrocyte sedimentation rate; PCT: Procalcitonin.