[Clinical assessment of colistin in treating infections caused by multidrug-resistant gram-negative bacillus in patients with severe burn].
OBJECTIVE
To investigate the therapeutic effect and side effects of colistin in treating infections caused by multidrug-resistant (MDR) gram-negative bacillus in patients with severe burn in order to provide the basis for reasonable application of this antibiotic in clinic.


METHODS
Nine burn patients suffered from infections caused by MDR gram-negative bacillus admitted to our institute from August 2005 to January 2009 were involved in this study. On the premises that isolated bacteria were only sensitive to colistin or not sensitive to other antibiotics, patients were treated with intravenous drip of colistin (100 x 10(4) - 150 x 10(4) U/d), or intravenous drip combined with administration of the drug into respiratory tract by atomization or instillation (50 x 10(4) - 100 x 10(4) U/d). The bacteriologic and therapeutic effects and side effects (including neurotoxicity and nephrotoxicity, rise in serum levels of creatinine, urea nitrogen and cystatin C were detected and compared before and after administration) of colistin were observed.


RESULTS
Out of 9 patients, 7 patients were with bloodstream and pulmonary infections, 1 patient was with bloodstream, pulmonary, and invasive wound infections, and 1 patient was with bloodstream and urinary tract infections. The pathogenic bacteria were proved to be Pseudomonas aeruginosa, Acinetobacter baumannii and Pseudomonas maltophilia. After the administration of colistin, bacteria clearance rate of blood reached 92.3% in 9 patients; isolation rate of MDR gram-negative bacillus of sputum was significantly decreased in 7 patients with pulmonary infection (before treatment 58.2% v.s. after treatment 14.6%, P < 0.01); a complete MDR gram-negative bacillus clearance of urine was observed in 1 patient with urinary tract infection. Colistin was clinically effective in 8 patients but ineffective in 1 patient (effective rate 88.9%). Compared with those before administration, serum levels of creatinine and urea nitrogen were decreased after administration in all patients; no significant difference in serum level of cystatin C among 8 patients was detected, except an obvious elevation in serum level of cystatin C in 1 patient after colistin therapy, and it lowered 1 month after discontinuation. No neurotoxicity or other side effect was observed during medication and 5 days after discontinuation in all patients.


CONCLUSIONS
Reasonable application of colistin is a good option for treating infections caused by MDR gram-negative bacillus in patients with severe burn, as no other more effective drug is found.
Zhang
Jia-ping
JP
Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns and Combined Injury, the Third Military Medical University, Chongqing 400038, China.
Yang
Xiao-shun
XS
Chen
Jian
J
Peng
Yi-zhi
YZ
Huang
Yue-sheng
YS
D000328:Adult; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000627:therapeutic use*; D002056:Burns / Q000188:drug therapy* / Q000382:microbiology; D003091:Colistin / Q000009:adverse effects / Q000627:therapeutic use*; D024901:Drug Resistance, Multiple, Bacterial; D006090:Gram-Negative Bacteria / Q000187:drug effects; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D003091:Colistin