Correlation Between Anesthesia Methods and Adverse Short-Term Postoperative Outcomes Depending on Frailty: A Prospective Cohort Study

Figures & data

Figure 1 Flow chart of the selection process.

Abbreviations: GA, general anesthesia; NA, Neuraxial anesthesia.

Table 1 Patient Demographics and Clinical Characteristics by Anesthesia Type

Characteristic	General Anesthesia (n = 262)	Neuraxial Anesthesia (n = 125)	P value
Age (mean±SD)	75.1 ± 6.4	79.5 ± 7.4	< 0.001**^∮
Sex (n%)			0.072^‡
Male	33.6	43.2
Female	66.4	56.8
BMI (kg/m^2)	23.5 ± 3.6	22.5 ± 3.8	0.005*^∮
Smoking (n%)	16.4	15.2	0.76^‡
Drinking (n%)	16.0	19.2	0.438^‡
ASA Score (n%)			0.001*^‡
II	56.5	43.5
III and IV	36.8	63.2
aCCI (IQR)	3.0 (2.0, 4.0)	4.0 (3.0, 5.0)	< 0.001**^†
Hemoglobin (mean±SD)	114.1± 18.9	112.0 ± 20.4	0.001*^∮
Albumin (mean±SD)	36.4 ± 4.1	36.4 ± 4.5	< 0.001**^∮
Hypoproteinemia(n%)	36.6	39.2	0.627^‡
Type of surgery(n%)			0.184^‡
Total Hip Replacement	53.8	46.4
Total knee replacement	11.8	9.6
Hip fracture surgery	34.4	44.0
FRAIL (n%)			0.001*^‡
Non- frail	34.7	17.6
Vulnerable	29.4	9.6
Frail	35.9	52.8
Days of hospitalization before surgery (mean±SD)	4.78± 3.1	4.5 ± 2.5	0.084^∮
Intraoperative blood transfusion (n%)	39.3	41.6	0.78^‡
Surgical time (mean±SD)	76.7± 27.7	63.6 ±24.4	< 0.001**^∮

Note:*P<0.05; ** P<0.001 ^∮Two independent samples t-test ^†Mann–Whitney U ^‡X²⁶/Fisher.

Abbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index; FRAIL, Frailty predictive phenotypes; aCCI, age-adjusted Charlson Comorbidity Index.

Table 2 Patient Demographics and Clinical Characteristics by Categorized Frailty

Characteristic	Non- frail (n = 113)	Vulnerable (n = 114)	Frail (n = 160)	P value
Age (IQR)	73 (6977) a	73 (7177) a	79 (7485) b	< 0.001**^§
Sex(n%)				0.399^‡
Male	31.9	40.4	37.5
Female	68.1	59.6	52.5
BMI (mean±SD)	23.5 ± 3.8	23.5 ± 3.5	22.7 ± 3.7	0.150^∭
Smoking (n%)	14.2	13.2	19.4	0.313^‡
Drinking (n%)	14.2	13.2	21.9	0.104^‡
ASA Score (n%)				< 0.001**^‡
II	64.6 a	64.0a	31.9 b
III and IV	35.4 ^a	35.9 a	68.1 b
aCCI (IQR)	3 (3,4) a	4 (3,5) b	5 (4,6) c	< 0.001**^§
Hemoglobin (mean±SD)	115.0 ± 18.6 a	117.6 ±19.2 a	109.3 ±19.3 b	< 0.001**^∭
Albumin (mean±SD)	37.0 ± 3.8 a	37.2 ± 4.1 a	35.3 ± 4.4 b	< 0.001**^∭
Hypoproteinemia (n%)	33.6 a, b	26.3 b	48.1 a	0.001*^‡
Type of surgery (n%)				0.008*^‡
Total Hip replacement	51.3 a, b	63.2 b	43.1 a
Total knee replacement	10.6 a	12.3 a	10.6 a
Hip fracture surgery	38.1 a, b	24.7 b	46.2 a
Type of anesthetic (n%)				0.001*^‡
General anesthesia	80.5 a	67.5 a, b	58.8 b
Neuraxial anesthesia	17.7 a	32.5 a, b	41.2 b
Days of hospitalization before surgery (mean±SD)	4.3 ± 2.6 a	4.3 ± 3.1 a	5.2 ± 3.1 b	0.011*^∭
Intraoperative blood transfusion (n%)	38.1	35.9	43.8	0.39^‡
Surgical time (mean±SD)	75.3 ± 27.1 ^a	76.1 ± 26.8 a	68.0 ± 27.4 b	0.024*^∭

Note: When comparing three sets of data, variables a and b are used to indicate comparability between the two groups (eg, a vs b, a vs c, b vs c), whereas variables with the same letter indicate lack of comparability between the two groups (eg, a vs a); *P<0.05; ** P<0.001 ^‡X²⁶/Fisher ^∭One-Way analysis of Variance ^§Kruskal–Wallis.

Abbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index; FRAIL, Frailty predictive phenotypes; aCCI, age-adjusted Charlson Comorbidity Index;

Table 3 Primary Outcome and Prespecified Secondary Outcomes by Categorized Anesthesia Type

Outcome	General anesthesia (n = 262)	Neuraxial anesthesia(n = 125)	P value
Primary outcome
Death or inability to walk without human assistance at 60 days (n%/)	24.0	36.0	0.011*^‡
Secondary outcomes
Death at 60 days (n%/)	4.2	2.4	0.642^‡
Walk without human assistance at 60 days (n%/)	19.4	33.6	0.008*^‡
Death or inability to walk without human assistance at 30 days (n%/)	27.9	35.2	0.142^‡
First time out of bed after surgery (day)	2 (1,4)	3 (1,5)	0.414^§
Postoperative blood transfusion (n%)	35 (13.4)	19 (15.2)	0.625^‡
Days of hospitalization (day)	9.5 (8,13)	10 (8,12)	0.327^§
Hospital fees (RMB)	35,168 (31,064,40,564)	34,765 (30,915,39,176)	0.509^§
Surgery-related complications at 60 days
Dislocation (n%/)	0	0.8	0.327^‡
Periprosthetic fracture (n%)	0.8	0	0.452^‡
Infection (n%)	0.8	2.4	0.199^‡
Reoperation (n%)	2.3	4	0.271^‡
Wound complications/hematoma, and mortality (n%)	2.3	1.6	0.483^‡

Note: *P<0.05; **P<0.001^‡X2/Fisher ^§Kruskal–Wallis.

Table 4 Primary Outcome and Prespecified Secondary Outcomes by Categorized Frailty

Outcome	Non-frail (n=113)	Vulnerable (n=114)	Frail (n=160)	P value
Primary outcome
Death or inability to walk without human assistance at 60 days (n%/)	10.6 a	21.9 a	43.8 b	< 0.001*^‡
Secondary outcomes
Death at 60 days (n%/)	0.8 a	7.0 b	3.0 a, b	0.045*^‡
Walk without human assistance at 60 days (n%/)	9.7 a	14.9 b	40.6 c	< 0.001**^‡
Death or inability to walk without human assistance at 30 days(n%/)	11.5 a	21.9 a	46.9 b	< 0.001**^‡
First time out of bed after surgery (day)	2 (1,4)	2 (1,4)	3 (1,5)	0.263 ^§
Postoperative blood transfusion (n%/)	8.8 a	11.4 a, b	19.4 b	0.03* ^‡
Days of hospitalization (day)	9 (8,11) a	9 (8,12) a	10 (9,14) b	< 0.001**^§
Hospital fees (RMB)	33,536 (30,054,38,071) a	33,756 (30,716,39,163) a	36,715 (32,267,42,842) b	0.002* ^§
Surgery-related complications
Dislocation (n%/)	0	0	1.3	0.342 ^‡
Periprosthetic fracture (n%/)	0	0	0.6	1 ^‡
Infection (n%/)	0	1.8	1.9	0.395 ^‡
Reoperation (n%/)	0 a	1.8 a	5.6 b	0.012* ^‡
Wound complications/hematoma, and mortality (n%/)	0.9 a	0 a	4.4 b	0.038* ^‡

Notes: When comparing three sets of data, variables a and b are used to indicate comparability between the two groups (eg, a vs b, a vs c, b vs c), whereas variables with the same letter indicate lack of comparability between the two groups (eg, a vs a). *P<0.05; **P<0.001 ^‡X²⁶/Fisher ^§Kruskal–Wallis.

Table 5 Binary Logistic Regression Analysis of Outcome Risk Factors for Death or a New Inability to Walk 60 Days Postoperatively

	Univariate analysis		Multivariate analysis
Variables	OR (95% CI)	P value	OR (95% CI)	P value
Age	1.04(1.01–1.07)	0.016*	1.05(1.00–1.10)	0.017*
Sex	0.73(0.46–1.15)	0.177
BMI	1.02(0.96–1.08)	0.538
Smoking	1.19(0.66–2.15)	0.565
Drinking	1.78(1.02–3.10)	0.043*	1.62(0.85–3.07)	0.141
FRAIL Scale
Non- frail*		< 0.001**		0.001*
Vulnerable	2.36(1.12–4.98)	0.024*	2.17(1.0–4.74)	0.050*
Frail	6.54(3.33–12.86)	< 0.001**	4.04(1.04–8.57)	< 0.001**
ASA
II*		< 0.001**
III and IV	2.67(1.68–4.25)	< 0.001**	1.59(0.90–2.78)	0.108
aCCI	1.51(1.30–1.76)	< 0.001**	1.36(1.12–1.66)	0.002*
Hemoglobin	0.99(0.94–0.99)	0.011*	0.99(0.98–1.01)	0.351
Albumin	0.95(0.90–1.00)	0.083
Hypoproteinemia	1.54(0.98–2.42)	0.064
Type of surgery
Total Hip Replacement		0.017*		0.533
Total knee replacement	0.74(0.32–1.70)	0.478	0.75(0.30–1.87)	0.543
Hip fracture surgery	1.81(1.13–2.90)	0.014*	1.30(0.70–2.40)	0.409
Type of anesthetic
General anesthesia*
Neuraxial anesthesia	1.82(1.14–2.88)	0.012*	1.42(0.83–2.42)	0.199
Days of hospitalization	1.11(1.02–1.19)	0.006*	1.04(0.96–1.13)	0.338
Intraoperative blood transfusion	1.20(0.76–1.88)	0.427
Surgical time	0.99(0.98–1.0)	0.356

Note:*P<0.05; **P<0.001.

Abbreviations: ASA, American Society of Anesthesiologists; aCCI, age-corrected Charlson comorbidity index.

Table 6 Preoperative Debilitating Status, Age, and aCCI Score Predicted Death or Impaired Ambulation at 60d Postoperatively

Characteristic	AUC	Sensitivity	Specificity	Youden index	Optimal thresholds
Year	0.581	0.579	0.564	0.144	76.0
aCCI	0.684	0.617	0.639	0.256	5.0
FRAIL Scale	0.691	0.654	0.679	0.333	3.0

Abbreviation: ASA, American Society of Anesthesiologists; aCCI age-corrected Charlson -comorbidity index.

Figure 2 ROC curves for age, preoperative frailty and aCCI predicting death or a new inability to walk 60 days.

Table 7 Patient Stratification of Debilitation and Anesthesia Methods by Type of Surgery

Characteristic	Total Hip replacement (n = 199)	Total knee replacement (n = 43)	Hip fracture surgery (n = 145)	P value
FRAIL				0.008^‡*
Non-frail	29.1	27.9	29.7
Vulnerable	36.2	32.6	19.3
Frailty	34.7	39.5	51.0
Type of anesthetic (n%)				0.184^‡
General anesthesia	70.9	72.1	62.1
Neuraxial anesthesia	29.1	29.9	39.9

Note:*P<0.05; **P<0.001 ^‡X²⁶/Fisher ^§Kruskal–Wallis.

Abbreviation: FRAIL, Frailty predictive phenotypes.

Table 8 Multivariate stratified regression models predicting death or impaired ambulation within 60 days after surgery

Variables	B	SE	β	t	R	R^2	▲R^2
Block 1					0.187	0.035	0.018*
					F (2,383) =3.604*
General anesthesia	0.111	0.048	0.116	2.310*
Neuraxial anesthesia (Ref.)
Total knee replacement	-0.049	0.074	-0.034	-0.656
Hip fracture surgery	0.113	0.048	0.122	2.327*
Total Hip Replacement (Ref.)
Block 2					0.344	0.118	0.083**
					F (4,381) =17.980**
General anesthesia	0.061	0.047	0.064	1.293
Neuraxial anesthesia (Ref.)
Total knee replacement	-0.060	0.071	-0.042	-0.846
Hip fracture surgery	0.086	0.047	0.093	1.824
Total Hip Replacement (Ref.)
Vulnerable	0.118	0.057	0.120	2.070*
Frailty	0.311	0.053	0.342	5.857**
Non-frail (Ref.)

Notes: Dependent variable was Y. *P<0.05; **P<0.001.

Figure 3 OR regression model for neuraxial anesthesia versus general anesthesia based on categorical frailty index using multivariate proportional hazards regression model.

Jiang L, Chou ACC, Nadkarni N, et al. Charlson comorbidity index predicts 5-year survivorship of surgically treated hip fracture patients. Geriatr Orthop Surg Rehabil. 2018;9:2151459318806442. doi:10.1177/2151459318806442

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