Nosocomial Infections in Nonsurgical Patients Undergoing Extracorporeal Membrane Oxygenation: A Retrospective Analysis in a Chinese Hospital

Figures & data

Table 1 Demographic and Clinical Characteristics of Patients Receiving Extracorporeal Membrane Oxygenation with and without Nosocomial Infections

Patients’ and Treatment Characteristics	Total, n=79	Non-Infected Patients, n=37	Infected Patients, n=42	P value
Age(yr)	53.3 (15.2)	48.8 (15.5)	57.3 (13.9)	0.014
Gender (male), n (%)	52 (66)	24 (65)	28 (67)	0.87
Smoking habits, n (%)	26 (33)	13 (35)	13 (31)	0.69
Charlson Comorbidity Index	1.9 (1.7)	1.6 (1.9)	2.2 (1.6)	0.037
Diagnosis at admission, n (%)
Respiratory disease	60 (76)	20 (54)	40 (95)	<0.001
Viral pneumonia	28 (35)	4 (11)	24 (57)	<0.001
Bacterial pneumonia	24 (30)	11 (30)	13 (31)	0.91
Other ^a	8 (10)	5 (14)	3 (7)	0.57
Cardiac disease	12 (15)	10 (27)	2 (5)	0.006
Poisoning	4 (5)	4 (11)	0 (0)	0.09
Septic shock	1 (1)	1 (3)	0 (0)	0.47
Other ^b	2 (3)	2 (5)	0 (0)	0.22
Underlying condition, n (%)
Malignancy	6 (8)	3 (8)	3 (7)	1.0
Hypertension	25 (32)	8 (22)	17 (40)	0.07
Diabetes mellitus	12 (15)	3 (8)	9 (21)	0.10
Renal insufficiency	5 (6)	2 (5)	3 (7)	1.0
Hepatic insufficiency	4 (5)	2 (5)	2 (5)	1.0
Coronary artery disease	4 (5)	3 (8)	1 (2)	0.52
Cerebrovascular accident	2 (3)	0 (0)	2 (5)	0.5
Immunocompromised states	9 (11)	2 (5)	7 (17)	0.22
Transplantation	3 (4)	0 (0)	3 (7)	0.29
Infection at admission, n (%)	56 (71)	18 (49)	38 (90)	<0.001
APACHE II score ^c	14.2 (5.7)	15.4 (6.5)	13.1 (4.8)	0.08
SOFA score ^c	5.3 (2.4)	5.4 (2.6)	5.3 (2.3)	0.95
PaO2/FiO2 < 100 mmHg, n (%)	19 (24)	9 (24)	10 (24)	0.96
ECMO duration, (d)	15.9 (14.1)	8.9 (5.3)	22 (16.5)	<0.001
Veno-venous ECMO, n (%)	61 (77)	23 (62)	38 (90)	0.003
IMV duration, (d)	19.9 (18.3)	11.4 (10.1)	27.4 (20.5)	<0.001
IMV duration before ECMO connection, (d)	2.5 (3.9)	2.4 (4.7)	2.5 (3.2)	0.15
IMV duration after ECMO connection, (d)	17.5 (17.7)	9.0 (8.3)	24.9 (20.5)	<0.001
Central venous catheter, n (%)	73 (92.4)	34 (91.9)	39 (92.9)	1.0
RRT before ECMO connection, n (%)	13 (17)	6 (16)	7 (17)	0.96
RRT during ECMO course, n (%)	44 (56)	18 (49)	26 (62)	0.24
WBC ^d, (*10^9/L)	12.5 (7.2)	13.9 (7.3)	11.3 (6.9)	0.08
Hemoglobin ^d, (g/L)	110 (30)	111 (28)	110 (31)	0.84
PLT ^d, (*10^9/L)	145 (96)	153 (89)	137 (102)	0.31
Transfusion, n (%)	66 (84)	29 (78)	37 (88)	0.25

Notes: Data are No. (%) of patients or mean value (± standard deviation). ^aIncluding interstitial pneumonia, pulmonary embolism, and lung cancer. ^bIncluding multiple trauma and hepatic failure. ^cCalculated at ICU admission. ^dRecorded at ECMO initiation.

Abbreviations: APACHE, acute physiology and chronic health evaluation; SOFA, sequential organ failure assessment; ECMO, extracorporeal membrane oxygenation; IMV, invasive mechanical ventilation; RRT, renal replacement therapy; WBC, white blood count; PLT, platelets.

Figure 1 Study flow chart.

Abbreviations: ECMO, extracorporeal membrane oxygenation; VAP, ventilator-associated pneumonia; IMV, invasive mechanical ventilation; ICU, intensive care unit; Nis, nosocomial infections; BSI, bloodstream infection; UTI, urinary tract infection.

Table 2 Microorganisms of Nosocomial Infections in 42 Patients Receiving Extracorporeal Membrane Oxygenation

VAP, n=30		BSI, n=19		UTI, n=4
Organism	No. (%)	Organism	No. (%)	Organism	No. (%)
Acinetobacter baumannii	16 (53)	Klebsiella pneumoniae	7 (37)	Candida albicans.	2 (50)
Klebsiella pneumoniae	4 (13)	Acinetobacter baumannii	4 (21)	Enterobacter faecium.	1 (25)
Polymicrobial ^a	4 (13)	S. aureus	2 (11)	Klebsiella pneumoniae	1 (25)
Pseudomonas aeruginosa	3 (10)	S. epidermidis	2 (11)
Burkholderia cepacia	2 (7)	Burkholderia cepacia	2 (11)
Stenotrophomonas maltophilia	1 (3)	Enterococcus faecium.	1 (5)
		Candida albicans.	1 (5)

Notes: ^aIncluding ≥ 2 pathogens; 2 Acinetobacter baumannii + Klebsiella pneumoniae, 1 Acinetobacter baumannii + Klebsiella pneumoniae + Aspergillus, 1 Acinetobacter baumannii + Pseudomonas aeruginosa.

Abbreviations: VAP, ventilator-associated pneumonia; BSI bloodstream infection; UTI urinary tract infection.

Table 3 Stepwise Logistic Regression Analysis of Factors Associated with Nosocomial Infections in Patients Receiving Extracorporeal Membrane Oxygenation

Factor	Univariate Analysis		Multivariate Analysis
	Odds Ratio (CI 95%)	P value	Odds Ratio (CI 95%)	P value
Age	1.040 (1.007–1.074)	0.017	–	–
Viral pnuemonia	11.000 (3.299–36.677)	<0.001	5.788 (1.551–21.596)	0.009
Cardiac disease	0.135 (0.027–0.665)	0.014	–	–
Infection at admission	10.028 (2.974–33.808)	<0.001	–	–
Veno-venous ECMO	5.783 (1.697–19.703)	0.005	–	–
ECMO duration	1.173 (1.078–1.275)	<0.001	1.141 (1.051–1.238)	0.002
IMV duration	1.090 (1.039–1.143)	<0.001	–	–

Abbreviations: ECMO, extracorporeal membrane oxygenation; IMV, invasive mechanical ventilation; CI, confidence interval.

Figure 2 Kaplan-Meier estimates of the unadjusted cumulative probability of staying free of NI.

Abbreviation: ECMO, extracorporeal membrane oxygenation.

Table 4 Stepwise Logistic Regression Analysis of Factors Associated with Mortality in the Intensive Care Unit

Factor	Univariate Analysis		Multivariate Analysis
	Odds Ratio (CI 95%)	P value	Odds Ratio (CI 95%)	P value
Charlson Comorbidity Index	1.579 (1.092–2.281)	0.015	–	–
PaO2/FiO2 < 100 mmHg	0.189 (0.040–0.896)	0.036	–	–
Hemoglobin amount ^a	0.976 (0.959–0.994)	0.009	0.968 (0.946–0.990)	0.005
PLT transfusion	8.532 (1.825–39.891)	0.006	10.433 (1.924–56.587)	0.007
BSI	5.284 (1.116–25.015)	0.036	8.106 (1.384–47.474)	0.020

Notes: ^aRecorded at ECMO initiation.

Abbreviations: PLT, platelet; BSI, bloodstream infection; CI, confidence interval.