Clinical variables predicting the risk of a hospital stay for longer than 7 days in patients with severe acute exacerbations of chronic obstructive pulmonary disease: a prospective study

Table 3 Microbiological variables

	Sputum sample collected in the previous year the hospitalisation				Sputum sample collectedduring the hospitalisation
	Number of cases	Normal LHS^a (≤ 7 days)	Prolonged LHS^a (> 7 days)	p value	Number of cases	Normal LHS^a (≤ 7 days)	Prolonged LHS^a (> 7 days)	p value
Patients with positive cultures	63	33	67	0.008	91	35	43	0.179
Number of pathogens: 0	373	51	49	0.031	346	51	49	0.138
1	43	33	67		89	39	61
≥ 2	20	35	65		2	50	50
Pseudomonas aeruginosa	16	13	87	0.041	25	12	88	0.001
Pseudomonas aeruginosa colonisation^c	–	–	–	–	9	0	100	0.002
Haemophilus influenzae	5	60	40	0.323	16	31	69	0.454
Streptococcus pneumoniae	7	43	57	0.677	18	61	39	0.037
Streptococcus spp.	5	20	80	0.657	–	–	–	–
Staphylococcus spp.	4	50	50	0.595	7	29	71	0.699
Pasteurella	–	–	–	–	2	50	50	> 0.999
Moraxella catarrhalis	3	67	33	0.256	3	100	0	0.059
Candida spp.	–	–	–	–	2	50	50	> 0.999
Aspergillus	–	–	–	–	2	50	50	> 0.999
Serratia	–	–	–	–	1	0	100	> 0.999
Escherichia coli	1	0	100	> 0.999	–	–	–	–
Mycobacterium no-TBC	–	–	–	–	1	100	0	0.396
Polymicrobial	20	35	65	0.848	8	50	50	0.708
Classification according to the conventional treatment^b: MSCT	31	45	55	0.026	51	51	49	0.014
MRCT	20	15	85		30	23	77
MRCT colonisation^c	–	–	–	–	10	10	90	0.009
Influenza B virus	–	–	–	–	2	50	50	> 0.999
Respiratory syncytial virus	–	–	–	–	7	43	57	> 0.999
Rhinovirus	–	–	–	–	7	29	71	0.450
Parainfluenza virus type 1	–	–	–	–	3	67	33	0.615
Parainfluenza virus type 3	–	–	–	–	3	0	100	0.499
Parainfluenza virus type 4	–	–	–	–	1	100	0	0.487

^aData reported as percentage related to number of cases for each of sputum sample. ^bPatients considered MSCT (for aminopenicillin with clavulanic acid, a macrolide or a tetracycline) or MRCT (Pseudomonas aeruginosa, MRSA, Stenotrophomonas maltophilia, Enterobacteriaceae producer of extended spectrum of beta lactamase and Acinetobacter baumannii) [2]. ^cColonisation was defined for a positive culture for the same microorganism in the sputum sample collected in the previous year and during hospitalisation. p value was calculated versus patients with a negative sample
Abbreviations: LHS, length hospital stay; MRSA, methicillin-resistant Staphylococcus aureus; MSCT and MRCT, microorganisms sensible and resistant to conventional treatment

ISSN: 1465-993X