Fig. 1.
Clinical outcomes in patients treated with intravenous and aerosolized polymyxin B or colistin
| Parameters | PMB group (N=106) | CLN group (N=116) | P value |
|---|---|---|---|
| Microbial eradication, n (%) | 88 (83) | 79 (68.1) | 0.001 |
| 21-day secondary bacterial infection, n (%) | 24 (22.64) | 28 (27.58) | 0.013 |
| Length-of-intubation (day), median (IQR) | 10 (9-12.25) | 14 (11-19) | 0.001 |
| Length-of-ICU stay (day), median (IQR) | 12 (10-14) | 15 (9-18.5) | 0.072 |
| Adverse drug event, n (%) | |||
| Bronchospasm | 39 (36.79) | 8 (6.89) | 0.001 |
| Nephrotoxicity | 12 (11.32) | 33 (28.44) | 0.002 |
Susceptibility of Klebsiella pneumoniae to all available antibiotics according to the CLSIa and EUCASTb guideline_
| Antibiotics | Clinical breakpoints (μg/mL) | MIC (μg/mL) | Interpretation | Comment: Type of resistance |
|---|---|---|---|---|
| Amikacin | ≤ 16, 32, ≥ 64 | > 16 | Resistant | Pandrug-resistant |
| Cefepime | ≤ 2, 4-8, ≥ 16 | > 16 | Resistant | |
| Cefixime | ≤ 1, 2, ≥ 4 | > 2 | Resistant | |
| Ceftazidime/Avibactam | ≤ 8/4, ≥ 16/4 | > 8/4 | Resistant | |
| Ceftriaxone | ≤ 1, 2, ≥ 4 | > 4 | Resistant | |
| Cefuroxime | ≤ 4, 8-16, ≥ 32 | > 8 | Resistant | |
| Ciprofloxacin | ≤ 1, 2, ≥ 4 | > 1 | Resistant | |
| Colistin | ≤ 2, ≥ 4 | > 2 | Resistant | |
| Gentamicin | ≤ 4, 8, ≥ 16 | > 4 | Resistant | |
| Imipenem | ≤ 1, 2, ≥ 4 | > 4 | Resistant | |
| Levofloxacin | ≤ 2, 4, ≥ 8 | > 2 | Resistant | |
| Meropenem | ≤ 1, 2, ≥ 4 | > 8 | Resistant | |
| Piperacillin/Tazobactam | ≤ 16/4, ≥ 28/4 | > 64/4 | Resistant | |
| Polymyxin B | ≤ 2, ≥ 4 | > 2 | Resistant | |
| Tigecycline | ≤ 1, 2, ≥ 2 | > 2 | Resistant |
Results from the Cox Proportional Hazard model_ GROUP=main variable (polymyxin B versus colistin)_
| Variable | HR | 95% CI | P value | |
|---|---|---|---|---|
| Lower | Upper | |||
| Group | 0.035 | 0.007 | 0.168 | <0.001 |
| Age | 1.028 | 1.001 | 1.055 | 0.045 |
| PaO2/FiO2 ratio | 1.005 | 0.994 | 1.015 | 0.379 |
| APACHE II | 0.958 | 0.862 | 1.063 | 0.415 |
| Microbial non-eradication | 1.148 | 0.484 | 2.721 | 0.038 |
| Length of intubation | 0.965 | 0.882 | 1.057 | 0.044 |
| Length of ICU stay | 1.043 | 0.99 | 1.099 | 0.117 |
Baseline demographic information, comorbidity and laboratory findings in patients_
| Variable | PMB group (N=106) | CLN group (N=116) | P value |
|---|---|---|---|
| Male/female, n (%) | 78/28 (74/26) | 62/54 (53/47) | |
| Age (year), median (IQR) | 56 (44.5-68) | 55 (46-65) | 0.091 |
| Fever (°F), median (IQR) | 100.5 (100-101) | 101 (100-101) | 0.559 |
| Diabetes, n (%) | 89 (83.95) | 97 (83.62) | 0.022 |
| Hypertension, n (%) | 72 (67.93) | 80 (68.96) | 0.421 |
| CVD, n (%) | 61 (57.52) | 53 (45.68) | 0.542 |
| Bronchial asthma, n (%) | 27 (25.51) | 30 (25.86) | 0.031 |
| CKD, n (%) | 25 (23.63) | 31 (26.72) | 0.011 |
| COPD, n (%) | 25 (23.6) | 27 (23.27) | 0.058 |
| Obesity, n (%) | 22 (20.82) | 18 (15.51) | 0.316 |
| PUD, n (%) | 19 (17.94) | 8 (6.89) | 0.644 |
| CLD, n (%) | 9 (8.55) | 12 (10.34) | 0.021 |
| PD, n (%) | 4 (3.86) | 9 (7.75) | 0.465 |
| SpO2 (%), median (IQR) | 96 (93-98) | 96 (94-98) | 0.249 |
| FiO2, median (IQR) | 50 (40-65) | 45 (40-65) | 0.939 |
| Respiratory rate, (breaths/min), median (IQR) | 19 (16-24) | 21 (18.29-24.7) | 0.487 |
| Heart rate (beat/min), median (IQR) | 87 (83-97.37) | 85 (78-90) | 0.487 |
| PaO2/FiO2 (mmHg) , median (IQR) | 240 (193-255) | 243 (206.72-256) | 0.517 |
| CRP (mg/L), median (IQR) | 158 (136-268.3) | 152.5 (125-243.81) | 0.282 |
| Procalcitonin (ng/mL), median (IQR) | 5 (3.35-8) | 6 (4.81-9) | 0.114 |
| WBC (K/μL), median (IQR) | 18 (16.52-21) | 16.46 (13.2-24) | 0.001 |
| Neutrophils (%), median (IQR) | 65 (55.77-75) | 75 (65-85) | 0.454 |
| Platelet (K/μL), median (IQR) | 186 (151-263) | 162 (125-242.5) | 0.132 |
| D-dimer (mg /L FEU), median (IQR) | 0.96 (0.36-1.74) | 0.57 (0.35-1.4) | 0.005 |
| LDH ((U/L), median (IQR) | 419 (314-522) | 425 (356.5-500.25) | 0.117 |
| Serum creatinine (mg/dL), median (IQR) | 0.9 (0.7-1.2) | 1 (0.8-1.6) | 0.097 |
| ALT (U/L), median (IQR) | 56 (45-76) | 57 (45-75) | 0.597 |
| AST (U/L), median (IQR) | 48 (39-58) | 46 (34-59) | 0.813 |
| Bilirubin (mg/dL), median (IQR) | 0.8 (0.47-0.9) | 0.8 (0.6-0.92) | 0.737 |
| MEWS, median (IQR) | 4 (3-4) | 4 (3-4) | 0.032 |
| APACHE II (score range: 0-71) , median (IQR) | 20 (20-24) | 20 (18-24) | 0.171 |