Impact of restriction of cefepime use on the antimicrobial susceptibility of Gram-negative bacilli related to healthcare-associated infections in an orthopedic hospital

Figures & data

Table 1 Comparison between the patients’ mean length of hospital stay, and the mean hospital mortality rates, (defined as the mean HAI rates and the numbers of GNB isolates relating to HAI), between the periods before and after restriction on cefepime use

	24-month period preceding restriction on cefepime use	24-month period subsequent to restriction on cefepime use	Pvalue
Mean length of hospital stay	7.05 days	6.88 days	0.145
Mean hospital mortality rate	0.78%	0.70%	0.509
Mean general HAI rate	3.78%	3.73%	0.984
Number of GNB isolates causing HAI	229 (50.7%)	224 (54.8%)	0.228

Abbreviations: HAI, healthcare-associated infections; GNB, Gram-negative bacilli.

Table 2 Comparison of the antimicrobial susceptibilities among the main GNB species involved in nosocomial infections, between the periods preceding and subsequent to restriction on cefepime use

Pathogen/Antibiotic (number of isolates tested before/after restriction on cefepime use)	Susceptibility (%) in 24-month period preceding restriction on cefepime use	Susceptibility (%) in 24-month period subsequent to restriction on cefepime use	Pvalue
A. baumanii
Amikacin (58/35)	13.8	14.3	>0.999
Ampicillin/Sulbactam (11/37)	90.9	78.4	0.662
Cefepime (50/35)	6	8.6	0.687
Ceftazidime (58/29)	8.6	6.9	>0.999
Ceftriaxone (48/37)	4.2	2.7	<0.999
Ciprofloxacin (48/30)	12.5	6.7	0.704
Gentamicin (57/37)	22.8	56.8	0.001
Imipenem (47/37)	95.7	56.8	<0.001
Trimethoprim-sulfamethoxazole (48/35)	18.8	14.3	0.592
P. aeruginosa
Amikacin (44/42)	75	66.7	0.395
Cefepime (30/41)	80	63.4	0.130
Ceftazidime (44/41)	61.4	65.9	0.667
Ciprofloxacin (31/40)	64.5	57.5	0.549
Gentamicin (43/41)	74.4	63.4	0.276
Imipenem (30/42)	83.3	66.7	0.114
Piperacillin/Tazobactam (7/36)	57.1	66.7	0.680
K. pneumoniae
Amikacin (39/29)	84.6	86.2	>0.999
Cefepime (20/29)	25	31	0.646
Ceftazidime (22/20)	18.2	25	0.714
Cefotaxime (20/15)	15	33.3	0.246
Ceftriaxone (19/14)	15.8	21.4	>0.999
Ciprofloxacin (36/29)	27.8	51.7	0.049
Gentamicin (39/29)	23.1	34.5	0.300
Imipenem (22/29)	100	100	*
Piperacillin/Tazobactam (3/20)	33.3	20	>0.999
Trimethoprim-sulfamethoxazole (39/29)	46.2	62.1	0.193
Enterobacterspp
Amikacin (32/37)	78.1	86.5	0.361
Cefepime (22/37)	72.7	75.7	0.801
Ceftazidime (26/32)	69.2	78.1	0.442
Cefotaxime (21/23)	47.6	69.6	0.139
Ceftriaxone (10/14)	50	48.1	0.421
Ciprofloxacin (27/37)	48.1	73	<0.043
Gentamicin (31/37)	83.9	83.8	0.992
Imipenem (27/37)	100	100	*
Trimethoprim-sulfamethoxazole (32/37)	32	37	0.227

Note:

* P values not able to be calculated because there were no cases of resistance.

Abbreviation: GNB, Gram-negative bacilli.

Table 3 Comparison of mean monthly consumption, in DDD/1000 patient-days, of antimicrobials with a spectrum of action directed against GNB, between the periods preceding and subsequent to restriction of cefepime use

Antimicrobial	Mean monthly consumption in the 24-month period preceding restriction on cefepime use	Mean monthly consumption in the 24-hour period subsequent to restriction on cefepime use	Pvalue
Amikacin	13.03	93.79	<0.001
Ampicillin/Sulbactam	76.62	66.64	0.156
Aztreonam	0.44	0.78	0.005
Cefepime	159.57	13.45	<0.001
Ceftriaxone	57.86	50.47	0.119
Ceftazidime	28.59	25.90	0.968
Ciprofloxacin	38.61	50.89	0.075
Colistin	0.86	0.01	<0.001
Ertapenem	10.05	20.50	0.003
Gentamicin	68.24	61.38	0.298
Imipenem	36.53	15.02	<0.001
Levofloxacin	1.29	2.73	0.020
Meropenem	14.76	17.56	0.589
Piperacillin/Tazobactam	1.46	2.15	0.136
Polymyxin B	0.07	0.03	0.555

Abbreviations: GNB, Gram-negative bacilli; DDD/1000, defined daily dose per thousand.