From March 2019 to December 2020, eight patients were excluded during the primary screening process. A total of 214 patients with an average age of 81.07 ± 4.78 (range, 75–100) years were included for analysis. The demographic and clinical characteristics of all patients are listed in Table 1. Of all patients, 112 (52.3%) underwent spinal fusion, 54 (25.2%) had total knee replacement, and 48 (22.4%) had total hip replacement. The most common comorbidity was hypertension, which was present preoperatively in 65.4% of the patients. Other common comorbidities were diabetes (24.8%), coronary heart disease (21.5%), cerebral infarction (14.3%), arrhythmia (6.3%), renal insufficiency (3.1%), and chronic obstructive pulmonary disease (3.5%). In addition, 26.6% of the patients had one comorbidity, 23.8% had two, 21% had three, 11.7% had more than three, and 16.8% had none. The mean number of comorbidities was 2.5 per patient (SD, 1.7).
Table 1
Patient Demographic and Clinical Characteristics
|
Patients (N = 214)
|
Characteristic
|
No.
|
%
|
Age, mean ± SD, y
|
81.07 ± 4.78
|
Male sex
|
72
|
33.6
|
BMI, mean ± SD
|
25.09 ± 4.17
|
Smoking (yes/no)
|
22
|
10.3
|
Alcohol (yes/no)
|
16
|
7.5
|
Comorbidities
|
|
0
|
36
|
16.8
|
1
|
56
|
26.2
|
2
|
51
|
23.8
|
3
|
45
|
21
|
>3
|
26
|
12.1
|
ASA scale
|
|
2
|
39
|
18.2
|
3
|
163
|
76.2
|
4
|
12
|
5.6
|
Type of surgery
|
|
-Spinal fusion
|
112
|
52.3
|
-Total knee replacement
|
54
|
25.2
|
-Total hip replacement
|
48
|
22.4
|
Surgical duration, mean ± SD, min
|
151.50 ± 86.74
|
Blood loss, mean ± SD, ml
|
285.53 ± 316.34
|
Abbreviations: |
ASA, American Society of Anesthesiologists; BMI, body mass index; SD, standard deviation. |
Postoperative outcomes and complications
One patient died of myocardial infarction 7 days after surgery, resulting in a mortality rate of 0.5%. A total number of 66 (30.8%) complications were registered. Implant-related complications are not discussed in this article. The most frequent postoperative complications were hypoproteinemia (albumin ≤ 30 g/L) (9.8%), followed by wound infection (3.7%), pneumonia (2.8%), urinary tract infection (2.3%), delirium (1.9%), transient arrhythmia (1.4%), pressure sores (1.4%), cerebral infarction (1.4%), myocardial infarction (1.4%), ileus (0.9%), gastrointestinal tract bleeding (0.9%), respiratory failure (0.9%), deep vein thrombosis (0.5%), cardiac failure (0.5%), and pulmonary embolus (0.5%). The mean hospital stay was 13.45 ± 7.46 days.
Comparisons of demographic and clinical characteristics between patients with and without complications are shown in Table 2. Patients undergoing spinal fusion and those with more blood loss tended to have higher risks of postoperative complications (p ≤ 0.002).
Table 2
Comparisons of Demographic and Clinical Characteristics between Patients with and without Complications
Characteristic
|
With complications
(n = 66)
|
Without complications
(n = 148)
|
p
|
Mean age
|
80.94 ± 4.57
|
81.14 ± 5.14
|
0.741
|
Male sex (n/%)
|
18 (27.3%)
|
54 (36.5%)
|
0.188
|
BMI
|
24.83 ± 4.48
|
25.21 ± 3.97
|
0.684
|
Smoking (yes/%)
|
10 (15.2%)
|
12 (8.1%)
|
0.117
|
Alcohol (yes/%)
|
7 (10.6%)
|
9 (6.1%)
|
0.245
|
Comorbidities
|
|
|
0.360
|
no
|
10
|
26
|
1
|
13
|
43
|
2
|
15
|
36
|
3
|
17
|
28
|
>3
|
11
|
15
|
ASA scale
|
|
|
0.289
|
2
|
13
|
26
|
3
|
47
|
116
|
4
|
6
|
6
|
Type of surgery
|
|
|
< 0.001 *
|
-Spinal fusion
|
44
|
68
|
-Total knee replacement
|
5
|
49
|
-Total hip replacement
|
17
|
31
|
Surgical duration (min)
|
160.46 ± 91.62
|
147.72 ± 81.60
|
0.475
|
Blood loss (ml)
|
438.65 ± 479.14
|
217.24 ± 252.75
|
0.002 *
|
Abbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index. |
*Significant differences between groups. |
Preoperative CGA results
All patients received a thorough CGA with multidisciplinary assessment completed within 48 h. About 63.1% of all patients had moderate or severe pain before surgery, 28.5% had severe or extremely severe dysfunction and were seriously dependent before surgery, 66.4% were frail, and 14% were malnourished before surgery. Most patients had satisfactory perioperative blood glucose control (89.25%) and normal thyroid function (86.92%). Renal function was stage 3a or worse in 101 (47.2%) patients, while 93.93% had normal liver function, as determined with the modified Child–Pugh classification.
Overall, 75 patients (35.05%) were at high risk for cardiac complications, 196 (91.59%) were at extremely high risk for thrombus, 176 patients (82.24%) had a high risk of massive hemorrhage. Respiration risk distributions were 0.5% (49 patients, 22.89%), 1.8% (88 patients, 41.12%), 4.2% (68 patients, 31.78%), and 10.1% (9 patients, 4.21%). In addition, the risk of stroke was high in 42 patients (19.63%), delirium in 16 (7.48%), falling in 11 (5.14%), and polypharmacy in 160 (74.77%).
Mild cognitive impairment was identified in 113 patients (52.8%). Five patients (2.34%) had anxiety and 5 (2.34%) had depression before surgery. The distribution of perioperative ASA scale was: grade II (42 patients, 19.63%), grade III (156 patients, 72.9%), and grade IV (16 patients, 7.47%).
Spearman correlation analysis was used to analyze the association among different evaluation items. Poor ADL and IADL were accompanied by frailty and worse ASA, VAS, and nutritional status. Poor ADL was also associated with higher risks of falling, polypharmacy, cardiac complications, and respiration complications. Poor IADL was associated with higher risks of cardiac and respiration complications. Higher stroke risk was accompanied with higher risks of cardiac complications, delirium, and hemorrhage. A poor ASA score was associated with worse ADL, IADL, frailty, and higher delirium risk. Other associations of CGA results are shown in a correlation matrix presented in Table 3.
Univariate Analysis of Potential Risk Factors Related to Complications
The associations between postoperative complications and domains of the CGA are listed in Table 4 (other domains are listed in supplementary file). Univariate analysis showed that six domains were significantly associated with postoperative complications. Patients with dependent ADL, dependent IADL, worse renal function, worse nutritional status, cognitive impairment, and low ASA scores tended to have higher risk of postoperative complications (p ≤ 0.0442).
Table 4
Univariate Analysis of Preoperative CGA Related to Postoperative Complications
|
Number (with any complication, %)
|
pa
|
ADL
|
|
0.0296 b
|
independent
|
21(19.0%)
|
mild dysfunction
|
58(23.7%)
|
moderate dysfunction
|
75(28.4%)
|
severe dysfunction
|
45(39.5%)
|
extremely severe dysfunction
|
15(58.8%)
|
IADL
|
|
0.0354 b
|
normal
|
34(17.6%)
|
mild dependence
|
39(25.6%)
|
moderate dependence
|
80(28.8%)
|
serious dependence
|
61(44.3%)
|
Nutrition (MNA)
|
|
0.0442 b
|
normal
|
114(23.7%)
|
at risk of malnutrition
|
70(37.1%)
|
malnourished
|
30(43.3%)
|
Cognitive impairment
|
|
0.0052 b
|
no impairment
|
101(19.8%)
|
mild impairment
|
113(40.7%)
|
Renal function
|
|
0.0134 b
|
normal
|
7(0%)
|
stage 1
|
22(22.7%)
|
stage 2
|
84(23.8%)
|
stage 3a
|
69(44.9%)
|
stage 3b
|
26(38.5%)
|
stage 4
|
4(0%)
|
stage 5
|
2(0%)
|
ASA score
|
|
0.0376 b
|
grade II
|
39(16.7%)
|
grade III
|
163(35.3%)
|
grade IV
|
12(25.0%)
|
Abbreviations: ADL, Activities of Daily Living; ASA, American Society of Anesthesiologists; IADL, Instrumental Activities of Daily Living; MNA, Mini nutritional assessment; VAS, visual analogue scale; . |
aKruskal–Wallis test. |
bSignificant differences among groups. |
Multivariate Analysis of Significant Univariate Factors
Eight potential risk factors (i.e., type of surgery, blood loss, ADL, IADL, nutritional status, renal function, ASA score, and cognitive impairment) were included for logistic regression analysis. Multivariate analysis showed that spinal fusion (odds ratio [OR], 0.73; 95% confidence interval [CI], 0.65 to 0.83; p = 0.0214), blood loss (OR, 1.68; 95% CI, 1.31 to 2.01; p = 0.0168), ADL (severe dysfunction or worse) (OR, 1.45; 95% CI, 1.16 to 1.81; p = 0.0413), IADL (serious dependence) (OR, 1.08; 95% CI, 1.33 to 1.63; p = 0.0436), renal function (CKD ≥ stage 3a) (OR, 2.01; 95% CI, 1.54 to 2.55; p = 0.0133), and malnutrition (MNA) (OR, 2.11; 95% CI, 1.74 to 2.56; p = 0.0101) were independent risk factors for postoperative complications (Fig. 1).