Table 1.
Baseline Demographics and Clinical Characteristics in the Modified Microbiologic Intent-to-Treat Population
| Baseline characteristic | IMI/REL (n = 21) | Colistin + IMI (n = 10) | Total (n = 31) |
|---|---|---|---|
| Sex | |||
| Male, n (%) | 13 (61.9) | 7 (70.0) | 20 (64.5) |
| Female, n (%) | 8 (38.1) | 3 (30.0) | 11 (35.5) |
| Age, y | |||
| <65, n (%) | 15 (71.4) | 5 (50.0) | 20 (64.5) |
| ≥65, n (%) | 6 (28.6) | 5 (50.0) | 11 (35.5) |
| Median (range) | 59 (19–75) | 61 (49–80) | 59 (19–80) |
| Weight, kg | |||
| Median (range) | 75 (53.0–132.3) | 75.6 (52.8–117.0) | 75 (52.8–132.3) |
| Creatinine clearance (mL/min) | |||
| ≥90, n (%) | 8 (38.1) | 3 (30.0) | 11 (35.5) |
| <90 to ≥60, n (%) | 8 (38.1) | 4 (40.0) | 12 (38.7) |
| <60 to ≥30, n (%) | 3 (14.3) | 2 (20.0) | 5 (16.1) |
| <30 to ≥15, n (%) | 1 (4.8) | 1 (10.0) | 2 (6.5) |
| Not available, n (%) | 1 (4.8) | 0 (0.0) | 1 (3.2) |
| Acute Physiology and Chronic Health Evaluation II score | |||
| ≤15, n (%) | 14 (66.7) | 8 (80.0) | 22 (71.0) |
| >15, n (%) | 7 (33.3) | 2 (20.0) | 9 (29.0) |
| Patients with HAP/VAP, median (range) | 16 (0, 26) | 22 (14, 23) | 18 (0, 26) |
| Patients with cIAI, median (range) | 18 (17, 19) | 14.5 (14, 15) | 16 (14, 19) |
| Patients with cUTI, median (range) | 5 (0, 17) | 7 (4, 15) | 5.5 (0, 17) |
| Primary diagnosis | |||
| HAP, n (%) | 1 (4.8) | 1 (10.0) | 2 (6.5) |
| VAP, n (%) | 7 (33.3) | 2 (20.0) | 9 (29.0) |
| cUTI (urinary tract abnormalities), n (%) | 5 (23.8) | 3 (30.0) | 8 (25.8) |
| cUTI (acute pyelonephritis), n (%) | 6 (28.6) | 2 (20.0) | 8 (25.8) |
| cIAI, n (%) | 2 (9.5)a | 2 (20.0)b | 4 (12.9) |
| Bacteremiac | |||
| Yes, n (%) | 1 (4.8) | 1 (10.0) | 2 (6.5) |
| No, n (%) | 5 (23.8) | 2 (20.0) | 7 (22.6) |
| Unknown, n (%)c | 15 (71.4) | 7 (70.0) | 22 (71.0) |
| Qualifying causative pathogens | |||
| Citrobacter freundii, n (%) | 1 (4.8) | 0 (0.0) | 1 (3.2) |
| Enterobacter cloacae, n (%) | 1 (4.8) | 0 (0.0) | 1 (3.2) |
| Klebsiella oxytoca, n (%) | 0 (0.0) | 1 (10.0) | 1 (3.2) |
| Klebsiella pneumoniae, n (%) | 3 (14.3) | 1 (10.0) | 4 (12.9) |
| Pseudomonas aeruginosa, n (%) | 16 (76.2) | 8 (80.0) | 24 (77.4) |
| β-lactamasesd | |||
| Class A | |||
| Older spectrum β-lactamases | |||
| SHVe | 2 (9.5) | 1 (10.0) | 3 (9.7) |
| TEM | 7 (33.3) | 3 (30.0) | 10 (32.3) |
| Extended spectrum β-lactamases | |||
| CTX-M | 7 (33.3) | 4 (40.0) | 11 (35.5) |
| SHVe | 1 (4.8) | 0 | 1 (3.2) |
| VEB | 0 | 0 | 0 |
| Serine carbapenemases | |||
| KPC | 4 (19.0) | 1 (10.0) | 5 (16.1) |
| Class C | |||
| Chromosomal AmpC | |||
| PDC | 16 (76.2) | 8 (80.0) | 24 (77.4) |
| Plasmid-mediated AmpC | |||
| ACT | 0 | 0 | 0 |
| CMY | 1 (4.8) | 0 | 1 (3.2) |
| DHA | 1 (4.8) | 0 | 1 (3.2) |
| Class D | |||
| OXA-48 | 0 | 1 (10.0) | 1 (3.2) |
Abbreviations: cIAI, complicated intraabdominal infection; cUTI, complicated urinary tract infection; HAP, hospital-acquired bacterial pneumonia; IMI, imipenem/cilastatin; IMI/REL, imipenem/cilastatin plus relebactam; KPC, Klebsiella pneumoniae carbapenemase; VAP, ventilator-associated bacterial pneumonia.
aPerforated colon (n = 1), liver abscess (n = 1).
bPerforated jejunum/ileum and colon, postsurgical peritonitis (n = 1), intraabdominal abscess (n = 1). cBaseline blood cultures were available from only 9 patients in the overall modified microbiologic intent-to-treat population.
dQualifying baseline pathogens could have had multiple β-lactamases detected. Of isolates with class A β-lactamases, all but 3 isolates carried multiple class A β-lactamases. A detailed breakdown by pathogen is provided in the Supplementary Materials.
eOlder spectrum β-lactamases were SHV-1 and SHV-11. Extended spectrum β-lactamase was SHV-28.