Abstract
Recently, Acinetobacter baumannii (Ab) infection has emerged as a serious problem among hospitalized patients. We thought to determine the association between antibiotic administered and outcome of patients with intensive infection in medical intensive care unit (ICU). The result will help choose antibiotic with regard to treatment of intensive infection in ICU.
45 patients with Ab infection were enrolled. The most common prescribed antibiotics were imipenem (38%), sulbactam (22%) and meropenem (16%). Overall clinical response to therapy was 71% , and bacteriological response was 60% . The 30-days survival rate was 51%.
Key Words: Acinetobacter baumannii; ICU; infection; clinical response; bacteriological response
Introduction
The emergence of Acinetobacter as significant nosocomial pathogen is related to both their survival ability and their rapid development of resistance to the major groups of antibiotics, resulting in a selective advantage in environments (such as ICU) with widespread and heavy antibiotic use1. Pneumonia is the most common manifestation of nosocomial Ab infection, accounting for 6.9 percent of gram-negative pneumonias in the ICU2. Nosocomial Ab infections are often due to multidrug-resistant (MDR) strains. Such infections often emerge in the setting of prolonged stay in the ICU and protracted exposure to antibiotics . Ab infection has emerged as a serious problem among hospitalized patients, especially in ICU3.
The most important predisposing factor of Ab infection is mechanical ventilation, especially after prolonged intubation. Other risk factors include underlying pulmonary disease and systemic co-morbidities, longer length of ICU stay, neurosurgery, and prior antibiotic therapy4. And those were the common pattern of ICU critically condition.
The objective of this study was to determine the association between antibiotics administered and outcome of patients with Ab infection in a 34 -bed medical ICU in a teaching hospital. The result will help choose antibiotics with regard to treatment of Ab infection in ICU.
Methods
This retrospective study was conducted in a 34 -bed medical ICU in a teaching hospital in southern Taiwan, between February 2006 and July 2008. We design the record of Ab utilization form. (Table 1). The eligible subjects were hospitalized patients admitted in medical ICU who were infected with Ab caused from blood, sputum, central venous pressure or urine culture. We excluded patients who prescribed with oral or inhale antibiotics regimen .The outcomes were the clinical response, bacteriological response and 30-days survival rate. A good clinical response referred to a combination of clinical cure and clinical improvement. Clinical cure was defined as resolution of any one of white blood count, body temperature or C-reactive protein. Successful bacteriological response was defined as eradication of the same causative organisms.
Table 1. Record of general characteristics of Acinetobacter baumannii infection
Chart No |
Bed No |
Date |
Age |
Sex |
□Male□Female |
|||||||||||||||
Drug |
IPM＊1 |
Tigecycline |
Cefpirome |
Cefepime |
Ciprofloxacin |
|||||||||||||||
Meropenem |
Sulbactam |
Unasyn＊2 |
Tazocin＊3 |
Ceftriaxone |
||||||||||||||||
Culture site of infection |
□Sputum□Blood□Urine |
□Wound□CVP＊4□Other |
||||||||||||||||||
Clinical response (post 48hrs) |
□WBC＊5↓ □Fever↓ □CRP＊6↓ |
|||||||||||||||||||
bacteriological response |
□Success □Failure |
|||||||||||||||||||
Strains |
□Ab＊7 □MDRAb＊8 |
|||||||||||||||||||
30-days mortality |
□Success □Failure |
|||||||||||||||||||
co-morbidities |
□RFa |
□RSFb |
□UTIc |
□PUd |
□DMe |
□COPDf |
||||||||||||||
□Pg |
□HTNh |
□CVAi |
□Sepsis |
□LCj |
□CHFk |
□CADl |
||||||||||||||
＊1imipenem ＊2Ampicillin & Sulbactam ＊3Piperacillin&Tazobactam ＊4Central Venous Pressure
＊5White blood count ＊6C-reactive protein ＊7Acinetobacter baumannii ＊8multidrug-resistant Acinetobacter baumannii
aRenal impairment bRespiratory failure cUrinary tract infection dPeptic ulcer eDiabetes mellitus fChronic Obstructive Pulmonary Disease gPneumonia hHypertension icerebrovascular accident
jLiver cirrosis kCongestive heart failure lCoronary Artery Disease
Results
45 patients with Ab infection were enrolled. 26 male and 19 female. The most common prescribed antibiotics were imipenem (38%), sulbactam (22%) and meropenem (16%). The infected sites were mostly sampled from blood, sputum and urine culture. MDRAb had 27 cases, and Ab had 18 cases. Overall clinical response to therapy was 71%, and bacteriological response was 60%. The 30-days survival rate was 51%. The associated co-morbidities were renal impairment (71%), pneumonia (58%), respiratory failure (47%). (Table 2)
We also compared the carbapenem spectrum antibiotic imipenem and meropenem, The imipenem group had better clinical response rate (76% vs. 57%) and bacteriological response rate (65% vs. 43%) than meropenem group. (Table 3)
Table 2. Baseline characteristics of the patients
Sexual |
patients |
% |
Male |
26 |
58 |
Female |
19 |
42 |
Age |
||
≤60 y/o |
13 |
29 |
61-80 y/o |
2 |
49 |
≥81y/o |
10 |
22 |
Medication |
||
Imipenem |
17＊1 |
38 |
Sulbactam |
10＊2 |
22 |
Meropenem |
7＊3 |
16 |
Unasyn |
6 |
13 |
Ciprofloxacin |
4 |
9 |
Cefepime |
2 |
4 |
Tazocin |
2 |
4 |
Ceftriaxone |
1 |
2 |
Cefpirome |
1 |
2 |
No antibiotics |
2 |
4 |
Culture site of infection |
||
Blood |
18＊4 |
40 |
Sputum |
9 |
20 |
Urine |
7 |
16 |
CVPa |
5＊5 |
12 |
Others |
6 |
13 |
Strains |
||
Multiple drug resistant Abb |
27 |
60 |
Ab |
18 |
40 |
Clinical response |
||
Improved |
32 |
71 |
No improced |
13 |
29 |
Bacteriological response |
||
Improved |
27 |
60 |
No improved |
18 |
40 |
30-days survival |
||
Survial |
23 |
51 |
Mortality |
22 |
49 |
Underlying condition |
||
Renal impairment |
32 |
71 |
Pneumonia |
26 |
58 |
Respiratory failure |
21 |
47 |
Diabetes mellitus |
18 |
40 |
Sepsis |
18 |
40 |
Urinary tract infection |
11 |
24 |
Peptic ulcer |
10 |
22 |
CHFc |
9 |
20 |
Hypertension |
9 |
20 |
Liver cirrosis |
8 |
18 |
COPDd |
8 |
18 |
CVAe |
5 |
11 |
CADf |
2 |
4 |
aCentral Venous Pressure bAcinetobacter baumannii ccongestive heart failure dChronic Obstructive Pulmonary Disease ecerebrovascular accident fCoronary Artery Disease
＊16 cases combinated with sulbactam ＊26 cases combines with imepenem,2 cases combined with meropenem ＊32 cases combined with sulbactam ＊41case the same culture result of blood and CVP ＊51case the same culture result of blood and CVP
Table 3. Compare imipenem and meropenem
Medication |
Imipenem (N=17) |
Meropenem (N=7) |
Monotherapy |
11 (65%) |
5 (71%) |
Combination |
6 (35%) |
2 (29%) |
Clinical response |
13 (76%) |
4 (57%) |
Bacteriological response |
11 (64%) |
3 (43%) |
30-days survival |
10 (59%) |
3 (43%) |
Conclusion
Nosocomial Acinetobacter pneumonia is associated with high mortality rates that range from 35 to 70 percent in different series and if positive blood cultures and signs of sepsis usually portend a bad prognosis5. Ab infection has emerged as a serious problem among hospitalized critically ill patients in ICU setting. Ab can develop resistance rapidly to different classes of antibiotics, including beta-lactams, aminoglycosides, fluoroquinolones, and tetracyclines. MDR strains have become progressively more common causes of nosocomial infections since the 1980s. Our observation suggested carbapenem antibiotics including imipenem and meropenem can be used to treat Ab infection with clinical or bacteriological response around 50%. Renal impairment and pneumonia could predispose to Ab infection.
The limitation of this research, we did not consider ventilator intubation, pre-antibiotic treatment, antibiotic regimen include dosage and duration and Acute Physiology and Chronic Health Evaluation (APACHII) severity score. The further study may be ruling out multiple factors that influent Ab infection, the result will help choose antibiotic with regard to treatment of Ab infection in ICU.
References:
1. Towner, KJ. Acinetobacter: an old friend, but a new enemy. J Hosp Infect 2009; 73:355-63.
2. Gaynes R, Edwards JR. Overview of nosocomial infections caused by gram-negative bacilli. Clin Infect Dis 2005; 41:848-54.
3. Sunenshine RH, Wright MO, Maragakis LL, et al: Multidrug-resistant Acinetobacter infection mortality rate and length of hospitalization. Emerg Infect Dis 2007; 13:97-103.
4. Baraibar, J, Correa, H, Mariscal, D, et al: Risk factors for infection by Acinetobacter baumannii in intubated patients with nosocomial pneumonia. Chest 1997; 112:1050-4.
5. Leung, WS, Chu, CM, Tsang, KY, et al: Fulminant community-acquired Acinetobacter baumannii pneumonia as a distinct clinical syndrome. Chest 2006; 129:102-9.
抗生素用於內科加護病房治療鮑式不動桿菌
摘要
鮑式不動桿菌 (Acinetobacter baumannii) 目前已經成為住院病患中一種非常嚴重的感染問題。本研究目的評估與分析在內科加護病房中，針對鮑式不動桿菌感染後，使用抗生素的治療結果。研究出來的結果有助於在加護病房中鮑式不動桿菌感染藥物的選擇。
報告指出共45位內科加護病房病患因鮑式不動桿菌感染而納入研究，使用藥品最多為imipenem (38%)，其次為sulbactam (22%) 與meropenem (16%)。藥物治療後臨床反應中有改善者有71%，微生物學反應中有改善者有60%。在使用藥物治療後30天仍存活有51%。
作者
高雄長庚紀念醫院藥劑部藥師 項怡平、
李炳鈺
高雄長庚紀念醫院醫師 方文豐
