Download Comparison of Peri-Operative Antimicrobial Prophylaxis Regimens

Contact Information:
Minkey Wungwattana, PharmD
Maine Medical Center – Department of Pharmacy
22 Bramhall Portland, ME 04102
Tel: (207) 662-1008 | Fax: (207) 662-6619
[email protected]
Comparison of Peri-Operative Antimicrobial Prophylaxis Regimens in Patients Receiving
Ventricular Assist Devices
I-wen Wang, MD, PhD
IU Health Methodist Hospital – Department of
Cardiothoracic Transplantation
1801 N. Senate Blvd, MPC2 Suite 3300
Indianapolis, IN 46202
Tel: (317) 963-1010 | Fax: (317) 962-2659
[email protected]
Minkey Wungwattana, PharmD1, Thomas C. Wozniak, MD2, Matthew F. Wack, MD2, David W. Smith, PharmD, BCPS AQ-ID3, Michael J. Latran, PharmD3, Kevin
Chen, BS2, Elizabeth M. Amerman, BSN, RN2, Tracie L. Layne, MSN, RN, CCRN2, Courtney A. Sheehan, PharmD3, BCPS, I-wen Wang, MD, PhD2
1Department
of Pharmacy, Maine Medical Center, Portland, ME; 2Department of Cardiothoracic Transplantation, IU Health, Indianapolis, IN; 3Department of Pharmacy, IU Health, Indianapolis, IN
Background




Ventricular assist device (VAD)-associated infections significantly increase morbidity and mortality, having been
identified as the primary cause of death in 16% of left ventricular assist device recipients from 2006 to 2009.1
Despite recognizing the need to prevent post-implantation infectious complications, there remains a lack of
consensus for the recommended peri-operative antimicrobial prophylaxis for VAD recipients.2,3,4
Various antimicrobial prophylaxis regimens have been described among many VAD implantation centers,
varying from single-agent regimens (9.5%) to four-agent regimens (42.9%).1
Table 1. Patient Demographics
Basic Demographics
Type of Implantation
With concerns of multi-drug resistant organisms on the rise, high importance continues to be placed on
providing adequate peri-operative antimicrobial prophylaxis while balancing the risk of resistance development.
Objective

Results
Compare clinical outcomes measured by infection rates between a two-drug (TDR) vs. a multi-drug (MDR)
(consisting of 3 or 4 agents) antimicrobial prophylaxis regimen among ventricular assist device patients at
Methodist Hospital (MH) in Indianapolis, IN.
Methods
Study Design
Inclusion Criteria
• Retrospective, non-randomized, single center analysis of VAD recipients at Methodist
Hospital in Indianapolis, IN from May 2008 to June 2012.
• Age ≥18 years
• Implantation of LVAD, RVAD, or BiVAD at MH
Exclusion Criteria
• Incomplete electronic medical records (with administered peri-operative medications)
Primary Endpoint
• Surgical site infections rates
• Bloodstream, respiratory, urinary, gastrointestinal, cardiovascular, and skin/soft tissue
infection rates
Secondary Endpoint(s)
• Cumulative infection events per patient
• Mortality at 1- and 6- months post-op
Statistical Analysis
• Descriptive statistics for baseline demographics
• Student’s t-test for continuous variables, Chi-squared (χ2) for categorical variables
• Kaplan-Meier analysis to assess time to first surgical site infection event
Multi-Drug Regimen, n = 31
Two-Drug Regimen, n = 56
p
Sex: male, frequency (%)
30 (96.8%)
40 (71.4%)
0.004
Age: mean years ± SD
53.4 ± 12.6
53.6 ± 12.4
0.943
BMI: mean ± SD
28.2 ± 4.6
28.7 ± 5.4
Destination Therapy (DT)
9 (29.0%)
Bridge to Transplant (BTT)
Bridge to Decision (BTD)
Device Type
Indication for VAD
Results (cont.)
Figure 3. Time To First Surgical Site Infection
Table 3. Isolated Microorganisms
MDR, n = 53
TDR, n = 71
p
Coagulase-neg staph.
4
6
0.855
0.665
Staphylococcus aureus
14
5
0.003
33 (58.9%)
0.008
Enterococcus spp.
0
10
0.004
20 (64.5%)
20 (35.7%)
0.009
Clostridium difficile
5
1
0.039
2 (6.5%)
2 (3.6%)
0.515
Corynebacterium spp.
1
0
0.245
Streptococci spp.
0
1
0.385
24 (45.3%)
23 (32.4%)
--
Gram Positive
Open
0 (0%)
1 (1.7%)
0.453
RVAD
0 (0%)
2 (3.6%)
0.293
BiVAD
2 (6.5%)
1 (1.7%)
0.262
Pseudomonas aeruginosa
5
12
0.232
LVAD
29 (93.5%)
53 (94.6%)
0.960
Serratia marcescens
6
4
0.250
Ischemic Heart Disease
14 (45.2%)
27 (48.2%)
0.843
Klebsiella spp.
6
16
0.106
Enterobacter spp.
3
8
0.277
Non-Ischemic Heart Disease
17 (54.8%)
29 (51.8%)
0.851
Escherichia coli
1
2
0.738
Citrobacter spp.
2
1
0.397
Proteus mirabilis
3
3
0.713
Moraxella catarrhalis
1
0
0.245
27 (50.9%)
46 (64.8%)
--
2 (3.8%)
2 (2.8%)
0.766
RVAD = right ventricular assist device, Bi-VAD = bi-ventricular assist device, LVAD = left ventricular assist device
Table 2. Types of Infections
Multi-Drug Regimen, n = 59
Two-Drug Regimen, n = 71
p
11 (18.6%)
6 (8.5%)
0.085
Surgical Site Infections (SSI)
Total
Freedom from Surgical Site Infection
Gram Negative
Total
Fungus
Blood Stream Infections (BSI)
9 (15.3%)
16 (22.5%)
0.294
Respiratory Tract Infections (RTI) / Pneumonia
16 (27.1%)
20 (28.2%)
0.897
Urinary Tract Infections (UTI)
12 (20.3%)
27 (38.0%)
0.029
Gastrointestinal Tract Infections (GI)
7 (11.9%)
1 (1.4%)
0.014
Cardiovascular System Infections (CVI)
2 (3.57%)
0 (0%)
0.119
Skin and Soft Tissue Infections (SSTI)
2 (3.57%)
1 (1.4%)
0.453
Candida spp.
Discussion

Overall, we did not detect a significant statistical difference in surgical site infection rates between a multi-drug
prophylaxis regimen and a two-drug prophylaxis regimen.

Despite a large decrease in fluconazole use prophylactically, there was no difference detected in the rate of
fungal infections in VAD recipients.

The shift from a MDR to a TDR resulted in a statistically significant increase in UTIs. Nevertheless, we also
detected a significant decrease in GI tract infections, the majority of which being Clostridium difficile colitis (75%
of all GI infections).

While there remains a lack of consensus for ventricular assist device implantation prophylaxis, our study shows
that a two-drug regimen may be effective in preventing surgical site infections while limiting exposure to
additional antimicrobial agents.
Figure 2. Antimicrobial Selection Distribution
Figure 1. Patient Allocation
References
1.
2.
3.
4.
**Note: Second agent in MDR cumulative > 100% due to two patients receiving
5 agents (β-lactam + FQ, as second agent)
Walker PC, et al. Surgical infection prophylaxis for left ventricular assist device implantation. J Card Surg 2011 Jul;26(4):440-3.
Engleman R, et al. The Society of Thoracic Surgeons Practice Guideline Series: Antibiotic Prophylaxis in Cardiac Surgery, Part II: Antibiotic
Choice. Ann Thorac Surg 2007 Apr;83(4):1569-76.
Acharya MN, et al. What is the optimum antibiotic prophylaxis in patients undergoing implantation of a left ventricular assist device? Interact
Cardiovasc Thorac Surg 2012 Feb;14(2):209-14.
Holman WL, et al. Infection in permanent circulatory support: experience from the REMATCH trial. J Heart Lung Transplant 2004 Dec;23(12):135965.
The authors do not have any financial disclosures or conflicts of interest.