In-Hospital Postoperative Pneumonia Following Geriatric Intertrochanteric Fracture Surgery: Incidence and Risk Factors

Figures & data

Figure 1 The flow chart for the selection of study participants.

Figure 2 The diagnosis time of IHPOP in patients.

Table 1 Optimum Cutoff Value of Continuous Variables Detected by the ROC Analysis

Variables	Cutoff Value	Area Under the ROC Curve (AUC)	P value	95% CI
Age (years)	82	0.673	0.000	0.588–0.758
BNP (ng/L)	75	0.676	0.000	0.602–0.750
LYM (%)	5.2	0.383	0.013	0.302–0.465
D-Dimer(mg/L)	2.26	0.626	0.000	0.537–0.714

Abbreviations: ROC, receiver-operating characteristic; CI, confidence interval; BNP, brain natriuretic peptide; LYM, lymphocyte.

Table 2 Comparison of Demographics and Fracture Characteristics Between the Two Groups

Variables	Overall (N=1495)	Without POP (N=1442)	With POP (N=53)	P value
Age (>82, years), n (%)	511(34.2)	480(33.3)	31(58.5)	<0.001
Sex (male), n (%)	547(36.6)	483 (33.5)	28 (52.8)	0.004
Residential location(urban), n (%)	689(46.1)	662 (45.9)	27 (50.9)	0.470
Hypertension, n (%)	724(48.8)	716 (49.7)	8 (45.3)	0.532
Diabetes, n (%)	328(21.9)	319 (22.1)	9 (17.0)	0.374
Cerebrovascular disease, n (%)	518(34.6)	492 (34.1)	26 (49.1)	0.025
Cardiovascular disease, n (%)	601(40.2)	565 (39.2)	36 (67.9)	<0.001
Chronic respiratory disease, n (%)	81(5.4)	69 (4.8)	12 (22.6)	<0.001
Smoking history, n (%)	70(4.7)	69 (4.8)	1 (1.9)	0.327
Tumors, n (%)	36(2.4)	36 (2.5)	0 (0.0)	0.244
Traumatic brain injury, n (%)	17(1.1)	17 (1.2)	0 (0.0)	0.427
Liver disease, n (%)	33(2.2)	28 (1.9)	5 (9.4)	<0.001
Renal disease, n (%)	49(3.2)	46 (3.2)	3 (5.7)	0.321
Urinary tract infection, n (%)	12(0.8)	9 (0.6)	3 (5.7)	<0.001
Rheumatoid diseases, n (%)	19(1.3)	19 (1.3)	0 (0.0)	0.400
Previous surgical history	235(15.7)	227 (15.7)	8 (15.1)	0.899
Comorbidities(no.), n (%)				<0.001
0	197(13.2)	197 (13.7)	0 (0.0)
1	340(22.7)	338 (23.4)	2 (3.8)
≥2	958(64.1)	907 (62.9)	51 (96.2)
ASA3-4, n (%)	802(53.6)	765 (53.1)	37 (69.8)	0.016
BMI, n (%)				0.011
<18.5	100(6.7)	91 (6.3)	9 (17.0)
18.5–24.9	860(57.5)	831 (57.6)	29 (54.7)
25–29.9	483(32.3)	471 (32.7)	12 (22.6)
≥30	52(3.5)	49 (3.4)	3 (5.7)
Injury mechanism (high energy), n (%)	80(5.4)	79 (5.5)	1 (1.9)	0.503
Side (left), n (%)	777(52.0)	747 (51.8)	30 (56.6)	0.492
Transfer to ICU (yes), n (%)	43(1495)	36(2.5)	7(13.2)	<0.001

Abbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index; ICU, intensive care unit.

Table 3 Comparison of Preoperative Laboratory Indicators Between the Two Groups

Variables	Without POP (N=1945)	With POP (N=53)	P value
TP <65 g/L, n (%)	1185(82.2)	47(88.7)	0.222
ALB<35g/L, n (%)	975(67.6)	37 (69.8)	0.737
GLOB (references 20–40 g/L), n (%)			0.693
<20	228(15.8)	7(13.2)
>40	12 (0.8)	0(0.0)
A/G (references 1.2–2.4), n (%)			0.676
<1.2	314(21.8)	13(24.5)
>2.4	16(1.1)	0(0.0)
ALT (references 9–50 U/L), n (%)			0.431
<9	162(11.2)	8(15.1)
>50	72(5.0)	1(1.9)
AST (references 15–40 U/L), n (%)			0.807
<15	269(18.7)	9(17.0)
>40	140(9.7)	4(7.5)
TBIL (>26), n (%)	192 (13.3)	9(17.0)	0.442
DBIL (>6), n (%)	648(44.9)	30(56.6)	0.145
IBIL (>14), n (%)	242(16.8)	10(18.9)	0.061
ALP (references 45–125 U/L), n (%)			0.720
<45	169(11.7)	7(13.2)
>125	92(6.4)	2(3.8)
GGT (references 10–60 U/L), n (%)			0.936
<10	83(5.8)	3(5.7)
>60	116(8.0)	5(9.4)
CHE (references 5–12 U/L), n (%)			0.254
<2	627(43.5)	29(54.7)
>12	5(0.3)	0(0.0)
TBA (references 1–10 umol/L), n (%)			0.411
<1	91(6.3)	3(5.7)
>10	164(11.4)	3(5.7)
HCRP (>8mg/L), n (%)	1210(83.9)	45(84.9)	0.846
CK (>310U/L), n (%)	297(20.6)	11(20.8)	0.978
CKMB (>20U/L), n (%)	219(15.2)	14(26.4)	0.027
LDH (>250U/L), n (%)	461(32.0)	16(30.2)	0.785
TC (>5.2 umol/L), n (%)	95(6.6)	2(3.8)	0.414
TG (>1.7 umol/L), n (%)	99(6.9)	4(7.5)	0.847
Na (references 137–147 mmol/L), n (%)			0.471
<137	663(46.0)	26(49.1)
>147	9(0.6)	1(1.9)
K (references 3.5–5.3 mmol/L), n (%)			0.610
<3.5	205 (14.2)	6(11.3)
>5.3	16(1.1)	0(0.0)
CL (references 99–110 mmol/L), n (%)			0.050
<99	225(15.6)	65(4.5)
>110	65(4.5)	6(11.3)
TCO2(references 20–30 mmol/L), n (%)			0.889
<20	69(4.8	3(5.7)
>30	721(5.0)	2(3.8)
GLU (>6.1), n (%)	868(60.2)	34(64.2)	0.761
UREA (>8), n (%)	327(22.8)	15(28.3)	0.320
CREA (references 57–97 mmol/L), n (%)			0.563
<57	623(43.2)	20(37.7)
>97	92(6.4)	5(9.4)
UA (references 208–428 mmol/L), n (%)			0.302
<208	729(40.6)	22(41.5)
>428	44(3.1)	3(5.7)
CA (references 2.11–2.52 mmol/L), n (%)			0.600
<2.11	761(52.8)	31(58.5)
>2.52	12(0.8)	0(0.0)
P (references 0.85–1.51 mmol/L), n (%)			0.579
<0.85	185(12.8)	9(17.0)
>1.51	50(3.5)	1(1.9)
Mg (references 0.75–1.02 mmol/L), n (%)			0.671
<0.75	167(11.6)	44(3.1)
>1.02	8(15.1)	1(1.9)
BNP (ng/L), n (%)			<0.001
<75	558(38.7)	9(17.0)
>75	416(28.8)	30(56.6)
Unknown	468(32.5)	14(26.4)
WBC (references 3.5–9.5*10^9/L), n (%)			0.307
<3.5	10(0.7)	0(0.0)
>9.5	513(35.6)	24(45.3)
NEU (references 2.8–6.3*10^9/L), n (%)			0.071
<1.8	3(0.3)	0(0.0)
>6.3	749(51.9)	36(67.9)
LYM (references 1.1–3.2*10^9/L), n (%)			0.818
<1.1	752(52.1)	29(54.7)
>3.2	8(0.6)	0(0)
MON (references 0.1–0.6*10^9/L), n (%)			0.520
<0. 1	3(0.2)	0(0)
>0.6	870(60.3)	36(67.9)
EOS (references 0.02–0.05*10^9/L), n (%)			0.052
<0.02	373(25.9)	9(17.0)
>0.52	4(0.3)	1(1.9)
BAS (>0.06), n (%)	83(5.8)	3(5.7)	0.977
RBC (>5.8), n (%)	94(6.5)	4(7.5)	0.766
NEU% (references 45–75%), n (%)			0.650
<45	3(0.2)	0(0.0)
>75	865(60.0)	35(66.0)
LYM% (>5.2), n (%)	1378(95.6)	50(94.3)	0.673
MON% (references 3–10%), n (%)			0.638
<3	24(1.7)	0(0.0)
>10	343(23.8)	13(24.5)
BAS% (>1%), n (%)	10(0.7)	11(0.7)	0.318
HGB (<110/120 g/L), n (%)	1334(92.5)	50(94.3)	0.618
MCV (references 82–100 fL), n (%)			0.086
<82	31(2.1)	0(0.0)
>100	110(7.6)	8(15.1)
MCH (references 27–34 pg), n (%)			0.189
<27	38(2.6)	0(0.0)
>34	92(6.4)	6(11.3)
MCHC (references 316–354 g/L), n (%)			0.074
<316	38(2.6)	3(5.7)
>354	61(4.2)	5(9.4)
RDW (references 11.6–16.5%), n (%)			0.912
<11.6	5(0.3)	0(0.0)
>16.5	136(9.4)	5(9.4)
PLT (references125–350 *10^9/L), n (%)			0.996
<125	135(9.4)	5(9.4)
>250	86(6.0)	3(5.7)
MPV (references7.4–11.0 fL), n (%)			0.246
<7.4	227(15.7)	12(22.6)
>11.0	49(3.4)	3(5.7)
PCT (references0.16–0.43%), n (%)			0.010
<0.16	937(65.0)	34(64.2)
>0.43	7(0.5)	2(3.8)
PDW (references12.0–18.1%), n (%)			0.934
<7.4	130(9.0)	4(7.5)
>11.0	26(1.8)	1(1.9)
PT (>12.5 S), n (%)	333(23.1)	10(18.9)	0.246
PTA (<80%), n (%)	175(12.1)	7(13.2)	0.873
INR (>1.4%), n (%)	11(0.8)	1(1.9)	0.368
APTT (references28–42 S), n (%)			0.934
<28	500(34.7)	24(45.3)
>42	20(1.4)	0(0.0)
APTT-R (references0.7–1.3), n (%)			0.528
<0.7	18(1.2)	0(0.0)
>1.3	16(1.1)	0(0.0)
TT (references14–21 S), n (%)			0.696
<14	1026(71.2)	35(66.0)
>21	151(10.5)	6(11.3)
FIB (reference2.0–4.4 mg/L), n (%)			0.708
<2.0	16(1.1)	0(0.0)
>4.4	350(24.3)	14(26.4)
AT III (reference80–120%), n (%)			0.916
<80	295(20.5)	12(22.6)
>120	33(2.3)	1(1.9)
D-Dimer (>2.26 mg/L), n (%)	571(39.6)	34(64.2)	<0.001

Notes: RBC, red blood cell, reference range: female, 3.5–5.0*1012/L; males, 4.0–5.5*1012/L; HGB, hemoglobin, reference range: females, 110–150g/L; males, 120–160g/L; HCT, haematocrit, 40–50%; PLT, platelet, 100–300*109/L.

Abbreviations: ASA, American Society of Anesthesiologists; BMI, body mass index; TP, total protein; ALB, albumin; GLOB, globulin; A/G values, albumin/globulin; ALT, alanine transaminase; AST, aspartate aminotransferase; TBIL, total bilirubin; DBIL, direct bilirubin; IBIL, indirect bilirubin; ALP, alkaline phosphatase; GGT, γ-glutamyl transpeptidase; CHE, cholinesterase; TBA, total bile acid; HCRP, hypersensitive c-reactive protein; LDH, lactate dehydrogenase; CREA, creatinine; UA, uric acid; CA, calcium; P, phosphorus; Mg, magnesium; BNP, brain natriuretic peptide; WBC, white blood cell; NEUT, neutrophile; LYM, lymphocyte, MON, mononuclear cell; EOS, eosinophilic granulocyte; BAS, basophilic granulocyte; MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; RDW, red blood cell distribution width; MPV, mean platelet volume; PCT, procalcitonin; pdw, platelet distribution width; PT, Prothrombin time; PTA, prothrombin activity; INR, international normalized ratio; APTT, activated partial thromboplastin time; APTT-R, activated partial thromboplastin time ratio; TT, thrombin time; TT-R, thrombin ratio; FIB, fibrinogen; AT III, antithrombin III.

Table 4 Comparison of Surgical Data Between the Two Groups

Variables	Without HPPOP (N=1442)	With HPPOP (N=53)	P value
Intraoperative blood loss (mL), n (%)	263.19(298.50)	265.09(204.65)	0.963
Intraoperative blood transfusion (mL),mean(SD)	133.67(318.19)	105.19(229.72)	0.519
Reduction methods (open reduction, n (%)	152 (10.5)	7 (13.2)	0.536
Surgeon (Deputy Chief Physician, n (%)	178 (12.3)	5 (9.4)	0.526
Time to surgery(days), mean (SD)	5.19 (3.93)	6.15 (4.92)	0.083
Type of anesthesia (general, n (%)	591 (41.1)	18 (34.0)	0.307
Implant, n (%)			0.169
Intramedullary devices	1351 (93.7)	53 (100.0)
Extramedullary devices	91 (6.3)	0 (0.0)
Duration of surgery(mins), mean (SD)	106.03(41.00)	100.19 (33.18)	0.306

Table 5 OR, 95% CI, and P value for Independent Risk Factors in the Multivariable Logistic Regression Analysis of IHPOP

Variables	OR	95% CI	P value
Age (>82 years)	2.54	1.354–4.760	0.004
Gender(female)	2.15	1.149–4.017	0.017
Chronic respiratory disease	5.02	2.283–11.043	0.000
Liver disease	3.39	1.074–10.675	0.037
Urinary tract infection	8.46	1.922–37.193	0.005
CKMB(>20U/L)	2.31	1.141–4.760	0.020
BNP			0.003
≥75 ng/L	4.02	1.795–9.010	0.001
Unknown	2.98	1.199–7.384	0.019
D-Dimer (>2.26 mg/L)	2.69	1.440–5.006	0.002

Abbreviations: OR, odds radio; CI, confidence interval; CKMB, creatine phosphokinase isoenzyme; BNP, brain natriuretic peptide.

Table 6 All Parameters in This Study

Clinical Data	Parameters
Demographics and fracture characteristics	Age, gender, residential location, hypertension, diabetes, cerebrovascular disease, cardiovascular disease, chronic respiratory disease, smoking history, tumors, traumatic brain injury, liver disease, renal disease, urinary tract infection, rheumatoid diseases, previous surgical history, the number of Comorbidities, ASA score, BMI, injury mechanism, side and transfer to ICU.
Preoperative laboratory indicators	TP, ALB, GLOB, A/G values, ALT, AST, TBIL, DBIL, IBIL, ALP, GGT, CHE, TBA, HCRP, LDH, CK, CKMB, TC, Na, K, CL, TCO2, GLU, urea, CREA, UA, CA, P, Mg, BNP, WBC, NEUT, LYM, MON, EOS, BAS, RBC, NEU%, LYM%, MON%, BAS%, HGB, HCT, MCV, MCH, MCHC, RDW, PLT, MPV, PCT, PDW, PT, PTA, INR, APTT, APTT-R, TT, TT-R, FIB, AT III and D-Dimer.
Surgical data	Intraoperative blood loss, intraoperative blood transfusion, reduction methods, surgeon, time to surgery, type of anesthesia, implant (intramedullary or extramedullary devices), and duration of surgery

Abbreviations: ASA, American Society of Anesthesiologists score; BMI, body mass index; ICU, intensive care unit; TP, total protein; ALB, albumin; GLOB, globulin; A/G, albumin/globulin; ALT, alanine transaminase; AST, aspartate aminotransferase; TBIL, total bilirubin; DBIL, direct bilirubin; IBIL, indirect bilirubin; ALP, alkaline phosphatase; GGT, γ-glutamyl transpeptidase; CHE,cholinesterase; TBA, total bile acid; HCRP, hypersensitive c-reactive protein; LDH, lactate dehydrogenase; CK, creatine kinase; CKMB, creatine kinase myoglobin; TC, total cholesterol; Na, sodium; K, kalium; CL, chlorin; TCO₂, Total carbon dioxide; GLU, glucose; CREA, urea, creatinine; UA, uric acid; CA, calcium; P, phosphorus; Mg, magnesium; BNP, brain natriuretic peptide; WBC, white blood cell; NEUT, neutrophile; LYM, lymphocyte; MON, mononuclear cell; EOS, eosinophilic granulocyte; BAS, basophilic granulocyte; RBC, red blood cell; HGB, hemoglobin; HCT, haematocrit; MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; RDW, red blood cell distribution width; PLT, platelet; MPV, mean platelet volume; PCT, procalcitonin; PDW, platelet distribution width; PT, prothrombin time; PTA, prothrombin activity; INR, international normalized ratio; APTT, activated partial thromboplastin time; APTT-R, activated partial thromboplastin time ratio; TT, thrombin time; TT-R, thrombin ratio; FIB, fibrinogen; AT III, antithrombin III.