Clinical Features and Antimicrobial Susceptibility of Pseudomonas aeruginosa and Acinetobacter baumannii Complex Isolates in Intensive Care Patients with Chronic Obstructive Pulmonary Disease and Community-Acquired Pneumonia in Taiwan

Figures & data

Table 1 Demographic and Clinical Characteristics of the Enrolled Participants

	Pseudomonas aeruginosa			Acinetobacter baumannii Complex			Pseudomonas aeruginosa and/or Acinetobacter baumannii Complex			Total
Characteristics	Positive (n=45)	Negative (n=217)	p value	Positive (n=30)	Negative (n=232)	p value	Positive (n=71)	Negative (n=191)	p value	(n=262)
Age (years)	77.8±10.2	78.9±8.6	0.445	76.8±9.2	79.0±8.8	0.208	77.5±9.9	79.2±8.4	0.182	78.7±8.9
Male gender	41(91.1%)	200(92.2%)	0.766	28(93.3%)	213(91.8%)	1.000	65(91.5%)	176(92.1%)	1.000	241(92.0%)
BMI (kg/m2)			0.046*			0.928			0.089
Available number	37(82.2%)	193(88.9%)		23(76.7%)	207(89.2%)		57(80.3%)	173(90.6%)		230(87.8%)
Mean ± SD	21.5±3.7	23.1±4.5		22.9±.2	22.8±4.4		22.0±4.0	23.1±4.5		22.8±4.4
Smoking history			0.066			0.689			0.101
Never	8(17.8%)	38(17.5%)		5(16.7%)	41(17.7%)		13(18.3%)	33(17.3%)		46(17.6%)
Ex-smoker	30(66.7%)	109(50.2%)		18(60.0%)	121(52.2%)		44(62.0%)	95(49.7%)		139(53.1%)
Current smoker	7(15.6%)	70(32.3%)		7(23.3%)	70(30.2%)		14(19.7%)	63(33.0%)		77(29.4%)
Spirometry (post-bronchodilator test)
FEV1/FVC (%)	49.6±13.2	52.2±10.8	0.210	55.3±10.5	51.3±11.3	0.071	51.8±12.7	51.8±10.7	0.995	51.8±11.2
FEV1 (L)	1.0±0.5	1.1±0.5	0.110	1.1±0.5	1.0±0.5	0.425	1.0±0.5	1.1±0.5	0.292	1.1±0.5
Positive bronchodilator test	8(17.8%)	26(12.0%)	0.418	1(3.3%)	33(14.2%)	0.145	9(12.7%)	25(13.1%)	1.000	34(13.0%)
COPD severity (GOLD spirometric classification)			0.042*			0.374			0.055
I	7(15.6%)	37(17.1%)		7(23.3%)	37(15.9%)		14(19.7%)	30(15.7%)		44(16.8%)
II	10(22.2%)	88(40.6%)		10(33.3%)	88(37.9%)		17(23.9%)	81(42.4%)		98(37.4%)
III	19(42.2%)	72(33.2%)		12(40.0%)	79(34.1%)		30(42.3%)	61(31.9%)		91(34.7%)
IV	9(20.0%)	20(9.2%)		1(3.3%)	28(12.1%)		10(14.1%)	19(9.9%)		29(11.1%)
COPD inhaled maintenance medications			0.237			0.949			0.433
ICS/LABA	4 (8.9%)	37(17.1%)		4(13.3%)	37(15.9%)		8(11.3%)	33(17.3%)		41(15.6%)
ICS/LABA + LAMA	5(11.1%)	42(19.4%)		5(16.7%)	42(18.1%)		10(14.1%)	37(19.4%)		47(17.9%)
LAMA alone	5(11.1%)	16(7.4%)		2(6.7%)	19(8.2%)		6(8.5%)	15(7.9%)		21(8.0%)
LABA alone	0(0.0%)	3(1.4%)		0(0.0%)	3(1.3%)		0(0.0%)	3(1.6%)		3(1.1%)
LABA + LAMA	1(2.2%)	1(0.5%)		0(0.0%)	2(0.9%)		1(1.4%)	1(0.5%)		2(0.8%)
None	30(66.7%)	118(54.4%)		19(63.3%)	129(55.6%)		46(64.8%)	102(53.4%)		148(56.5%)
Use of systemic steroids			0.177			0.597			0.461
Available number	44(97.7%)	215(99.0%)		30(100.0%)	229(98.7%)		70(98.5%)	189(98.9%)		259(98.9%)
Use	36(81.8%)	194(90.2%)		28(93.3%)	202(88.2%)		60(85.7%)	170(89.9%)		230(88.8%)
Use of methylxanthines	15(33.3%)	84(38.7%)	0.611	10(33.3%)	89(38.4%)	0.738	24(33.8%)	75(39.3%)	0.504	99(37.8%)
Prior antibiotic use within 3 months	18(40.0%)	63(29.0%)	0.204	10(33.3%)	71(30.6%)	0.925	28(39.4%)	53(27.7%)	0.095	81(30.9%)
Prior admission within 3 months	12(26.7%)	49(22.6%)	0.692	6(26.7%)	53(22.8%)	0.813	20(28.2%)	41(21.5%)	0.329	61(23.3%)
Co-morbidities
Cardiovascular disease‡	28(62.2%)	123(56.7%)	0.604	18(60.0%)	133(57.3%)	0.934	43(60.6%)	108(56.5%)	0.657	111(42.4%)
Cerebrovascular accident	9(20.0%)	39(18.0%)	0.914	8(26.7%)	40(17.2%)	0.315	16(22.5%)	32(16.8%)	0.370	48(18.3%)
Diabetes mellitus	10(22.2%)	36(16.6%)	0.491	2(6.7%)	44(19.0%)	0.158	12(16.9%)	34(17.8%)	1.000	46(17.6%)
Hypertension	17(37.8%)	94(43.3%)	0.604	10(33.3%)	101(43.5%)	0.386	26(36.6%)	85(44.5%)	0.314	111(42.4%)
Malignancy (except for lung cancer)	11(24.4%)	41(18.9%)	0.519	7(23.3%)	45(19.4%)	0.791	17(23.9%)	35(18.3%)	0.401	52(19.8%)
Modified GCS#	8.8±2.7	8.5±3.0	0.460	8.9±2.9	8.5±3.0	0.461	9.0±2.7	8.4±3.0	0.112	8.5±2.9
APACHE II score	21.9±6.2	21.4±5.9	0.572	21.9±7.4	21.4±5.8	0.732	21.7±6.5	21.4±5.8	0.756	21.5±6.0
Pneumonia severity index	116.2±25.5	121.4±32.6	0.320	115.9±31.0	121.1±31.6	0.399	115.5±28.1	122.4±32.6	0.114	120.5±31.5
I	1(2.2%)	0(0.0%)		0(0.0%)	1(0.4%)		1(1.4%)	0(0.0%)		1(0.4%)
II	0(0.0%)	7(3.2%)		1(3.3%)	6(2.6%)		1(1.4%)	6(3.1%)		7(2.7%)
III	6(13.3%)	34(15.7%)		5(16.7%)	35(15.1%)		11(15.5%)	29(15.2%)		40(15.3%)
IV	24(53.3%)	103(47.5%)		16(53.3%)	111(47.8%)		38(53.5%)	89(46.6%)		127(48.5%)
V	14(31.1%)	73(33.6%)		8(26.7%)	79(34.1%)		20(28.2)	67(35.1%)		87(33.2%)
Chest X-ray findings			0.125			0.790			0.197
Unilateral	42(93.3%)	180(82.9%)		25(83.3%)	197(84.9%)		64(90.1%)	158(82.7%)		222(84.7%)
Bilateral	3(6.7%)	37(17.1%)		5(16.7%)	35(15.1%)		7(9.9%)	33(17.3%)		40(15.3%)
Laboratory findings
WBC (x1000)/μL	10.0±3.7	11.0±5.0	0.201	10.5±6.5	10.9±4.5	0.791	10.4±5.0	11.0±4.7	0.382	10.8±4.8
Blood eosinophil percentage > 2%	9(20.0%)	23(10.6%)	0.133	4(13.3%)	28(12.1%)	0.771	11(15.5%)	21(11.0%)	0.438	32(12.2%)
Blood absolute eosinophil count > 300 cells/μL	32(71.1%)	137(63.1%)	0.397	22(73.3%)	147(63.4%)	0.384	51(71.8%)	118(61.8%)	0.172	169(64.5%)
Hemoglobin (g/dL)	11.6±2.2	11.9±2.3	0.326	11.4±2.2	11.9±2.3	0.254	11.6±2.2	12.0±2.4	0.307	11.9±2.3
High-sensitive CRP (mg/dL)			0.805			0.193			0.447
Available number	42(93.3%)	213(98.2%)		30(100%)	225(97.0%)		68(95.8%)	187(97.9%)		255(97.3%)
Mean±SD	8.4±8.8	8.1±8.5		10.0±8.4	7.9±8.5		8.8±8.0	7.9±8.7		8.1±8.5
Albumin (g/dL)			0.497			0.000*			0.021*
Available number	39(86.7%)	197(90.8%)		29(96.7%)	207(89.2%)		64(90.1%)	172(90.1%)		236(90.1%)
Mean±SD	3.0±0.8	3.1±0.6		2.7±0.4	3.1±0.7		2.9±0.7	3.1±0.6		3.0±0.7
BUN (mg/dL)			0.902			0.766			0.992
Available number	44(97.8%)	216(99.5%)		30(100%)	230(99.1%)		70(98.6%)	190(99.5%)		260(99.2%)
Mean±SD	28.7±18.8	28.4±15.9		29.3±15.5	28.3±16.5		28.4±17.0	28.4±16.2		28.4±16.4
Creatinine (mg/dL)	1.5±1.7	1.4±1.3	0.819	1.3±0.7	1.5±1.4	0.586	1.4±1.4	1.5±1.3	0.692	1.4±1.3
pH	7.4±0.1	7.4±0.1	0.751	7.4±0.1	7.4±0.1	0.170	7.4±0.1	7.4±0.1	0.945	7.4±0.1
PaCO2 (mmHg)	41.7±10.3	40.7±10.1	0.545	39.6±9.3	41.0±10.2	0.460	41.1±10.0	40.8±10.1	0.804	40.9±10.1
PaO2/FiO2 ratio			0.519			0.734			0.664
Available number	42(93.3%)	201(92.6%)		27(90.0%)	216(93.1%)		65(91.5%)	178(93.2%)		243(92.7%)
Mean±SD	226.7±124.9	214.4±110.0		209.6±101.7	217.4±114.0		221.7±117.4	214.6±111.0		216.5±112.5
Lactate (mg/dL)			0.995			0.401			0.755
Available number	34(75.6%)	177(81.6%)		25(83.3%)	186(80.2%)		55(77.5%)	156(81.7%)		211(80.5%)
Mean±SD	19.7±15.4	19.7±13.2		17.6±8.4	20.0±14.1		19.2±13.1	19.9±13.7		19.7±13.5
Use of antibiotics while microbiological sampling	25(55.6%)	91(41.9%)	0.131	17(56.7%)	99(42.7%)	0.209	39(54.9%)	77(40.3%)	0.051	116(44.3%)

Notes: *p<0.05. ^‡ Cardiovascular disease included ischemic heart disease, heart failure, and atrial fibrillation. ^# Modified GCS with verbal score as one.

Abbreviations: APACHE II score, Acute Physiology and Chronic Health Evaluation II score; BMI, body mass index; BUN, blood urea nitrogen; COPD, chronic obstructive pulmonary disease; CRP, C-reactive protein; FEV1, forced expiratory volume in one second; FiO2, fractional inspired oxygen; FVC, forced vital capacity; GCS, Glasgow Coma Scale; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid; LABA, long-acting beta-agonist; LAMA, long-acting muscarinic antagonist; PaCO2, partial pressure of carbon dioxide; PaO2, arterial oxygen partial pressure; SD, standard deviation; WBC, white blood count.

Figure 1 Independent factors associated with the presence of Pseudomonas aeruginosa and Acinetobacter baumannii complex discovered from endotracheal aspirate cultures. *p<0.05.

Abbreviations: CI, confidence interval; also see Table 1.

Table 2 Clinical Outcomes in the Respiratory Intensive Care Unit for the Enrolled Patients by Study Group

Outcomes	Pseudomonas aeruginosa			Acinetobacter baumannii Complex			Pseudomonas aeruginosa and/or Acinetobacter baumannii Complex			Total
	Positive (n=45)	Negative (n=217)	p value	Positive (n=30)	Negative (n=232)	p value	Positive (n=71)	Negative (n=191)	p value	(n=262)
RICU length of stay			0.223			0.871			0.510
≦14 days	23 (51.1%)	134 (61.8%)		19 (63.3%)	138 (59.5%)		40 (56.3%)	117 (61.3%)		157 (59.9%)
>14 days	22 (48.9%)	83 (38.2%)		11 (36.7%)	94 (40.5%)		31 (43.7%)	74 (38.7%)		105 (40.1%)
Weaning^‡			0.048*			1.000			0.117
Failure	28 (62.2%)	97 (44.7%)		14 (46.7%)	111 (47.8%)		40 (56.3%)	85 (44.5%)		125 (47.7%)
Success	17 (37.8%)	120 (55.3%)		16 (53.3%)	121 (52.2%)		31 (43.7%)	106 (55.5%)		137 (52.3%)
Death			0.010*			0.560			0.304
Yes	13 (28.9%)	27 (12.4%)		3 (10.0%)	37 (15.9%)		14 (19.7%)	26 (13.6%)		40 (15.3%)
No	32 (71.1%)	190 (87.6%)		27 (90.0%)	195 (84.1%)		57 (80.3%)	165 (86.4%)		222 (84.7%)

Notes: *p<0.05. ^‡The patients with a treatment outcome of death were considered as failed weaning.

Abbreviation: RICU, respiratory intensive care unit.

Table 3 Antimicrobial Susceptibility of 45 Endotracheal Aspirate Isolates of Pseudomonas aeruginosa

Antimicrobial Agent	All Isolates (n=45)
	Susceptible	Intermediate	Resistant
Gentamicin	43 (95.6%)	0 (0.0%)	2 (4.4%)
Amikacin	44 (97.8%)	1 (2.2%)	0 (0.0%)
Imipenem/Cilastatin	44 (97.8%)	0 (0.0%)	1 (2.2%)
Ceftazidime	43 (95.6%)	0 (0.0%)	2 (4.4%)
Cefepime	40 (88.9%)	2 (4.4%)	3 (6.7%)
Ciprofloxacin	43 (95.6%)	0 (0.0%)	2 (4.4%)
Piperacillin/Tazobactam	39 (86.7%)	0 (0.0%)	6 (13.3%)
Levofloxacin	42 (93.3%)	1 (2.2%)	2 (4.4%)
Meropenem	44 (97.8%)	0 (0.0%)	1 (2.2%)

Table 4 Antimicrobial Susceptibility of 30 Endotracheal Aspirate Isolates of Acinetobacter baumannii Complex

Antimicrobial Agent	All Isolates (n=30)
	Susceptible	Intermediate	Resistant
Gentamicin	7 (23.3%)	1 (3.3%)	22 (73.3%)
Ampicillin/Sulbactam	12 (40.0%)	1 (3.3%)	17 (56.7%)
Sulfamethoxazole/Trimethoprim	7 (23.3%)	0 (0.0%)	23 (76.7%)
Imipenem/Cilastatin	9 (30.0%)	1 (3.3%)	20 (66.7%)
Ceftazidime	8 (26.7%)	2 (6.7%)	22 (73.3%)
Cefepime	8 (26.7%)	1 (3.3%)	21 (70.0%)
Ciprofloxacin	8 (26.7%)	0 (0.0%)	22 (73.3%)
Piperacillin/Tazobactam	8 (26.7%)	1 (3.3%)	22 (73.3%)
Tigecycline	28 (93.3%)	2 (6.7%)	0 (0.0%)