Table 1 Summary of demography and baseline characteristics
| Â | Before propensity score (PS) | After propensity score (PS) | ||||||
|---|---|---|---|---|---|---|---|---|
Overall (N = 815) | Control (N = 739) | iNO (N = 76) | p-value | Overall (210) | Control (N = 140) | iNO (N = 70) | p-value | |
Age (years), mean (SD) | 62.5 (14.27) | 62.7 (14.33) | 61.0 (13.69) | 0.2474^ | 60.1 (14.40) | 60.2 (14.93) | 60.0 (13.38) | 0.9327* |
Gender – male, n (%) | 488 (60.2) | 447 (60.7) | 41 (54.7) | 0.3066^^ | 120 (57.1) | 80 (57.1) | 40 (57.1) |  > 0.9999^^ |
Weight (kg), mean (SD) | 82.0 (19.04) | 81.4 (18.05) | 88.2 (26.28) | 0.0604^ | 87.2 (22.86) | 86.0 (20.92) | 89.7 (26.41) | 0.5159^ |
Body mass index (BMI), mean (SD) | 31.5 (9.02) | 31.3 (8.88) | 33.7 (10.03) | 0.0427^ | 33.6 (9.20) | 33.5 (8.65) | 33.9 (10.26) | 0.8059^ |
APACHE II score, median (Q1,Q3) | 15.0 (10.00, 22.00) | 15.0 (10.00, 22.00) | 15.0 (9.50, 21.00) | 0.8583^ | 14.0 (10.00, 21.00) | 14.0 (10.00, 21.00) | 15.0 (9.00, 21.00) | 0.9681^ |
SOFA score, median (Q1,Q3) | 5.0 (3.00, 7.00) | 5.0 (3.00, 7.00) | 5.0 (4.00, 7.50) | 0.2367^ | 5.0 (4.00, 8.00) | 5.0 (4.00, 8.00) | 5.0 (4.00, 8.00) | 0.6282^ |
Multiple organ dysfunction (MOD)Â score at admission, median (Q1,Q3) | 5.0 (4.00, 7.00) | 5.0 (4.00, 7.00) | 6.0 (5.00, 8.00) | 0.3732^ | 6.0 (5.00, 8.00) | 6.0 (5.00, 7.00) | 6.0 (5.00, 8.50) | 0.8699^ |
Early use of dexamethasone within 24Â h, n (%) | 539 (66.1) | 482 (65.2) | 57 (75.0) | 0.0864^^ | 156 (74.3) | 102 (72.9) | 54 (77.1) | 0.5029^^ |
Early use of tocilizumab within 24Â h, n (%) | 174 (21.3) | 150 (20.3) | 24 (31.6) | 0.0223^^ | 76 (36.2) | 54 (38.6) | 22 (31.4) | 0.3099^^ |
Serum creatinine (mmol/L) at admission, median (Q1,Q3) | 86.0 (67.00, 116.00) | 86.0 (67.00, 115.00) | 87.5 (67.00, 127.50) | 0.3247^ | 87.5 (67.00, 134.00) | 87.0 (66.50, 134.00) | 91.5 (68.00, 133.00) | 0.6028^ |
Blood urea nitrogen (BUN) at admission (mmol/l), median (Q1,Q3) | 6.8 (4.80, 10.00) | 6.8 (4.80, 10.10) | 6.0 (4.80, 9.30) | 0.2394^ | 6.5 (4.70, 10.30) | 6.8 (4.35, 10.70) | 6.0 (4.90, 9.30) | 0.3616^ |
Acute Kidney Injury (AKI) within 24Â h of ICU admission, n (%) | 229 (28.3) | 204 (27.8) | 25 (32.9) | 0.3509^^ | 64 (30.6) | 40 (28.8) | 24 (34.3) | 0.4148^^ |
PaO2/FiO2 ratio within 24Â h of admission, Median (Q1,Q3) | 77.6 (59.30, 109.17) | 77.7 (59.25, 110.00) | 74.4 (59.82, 98.00) | 0.4691^ | 71.1 (58.00, 99.71) | 70.7 (57.50, 101.75) | 72.9 (59.33, 95.29) | 0.9443^ |
A-A gradient, median (Q1,Q3) | 456.2 (327.06, 579.88) | 450.7 (325.57, 579.65) | 487.7 (369.68, 587.59) | 0.1639^ | 474.2 (337.09, 589.60) | 461.7 (324.66, 585.20) | 492.1 (395.67, 600.70) | 0.2523^ |
Oxygenation index (OI), median (Q1,Q3) | 19.0 (12.16, 28.72) | 18.8 (12.15, 28.41) | 22.9 (12.73, 32.63) | 0.4719^ | 22.4 (12.73, 29.51) | 20.5 (12.54, 28.91) | 23.1 (12.73, 37.04) | 0.5806^ |
Inotropes/vasopressors use within 24Â h of admission, n (%) | 228 (28.3) | 200 (27.4) | 28 (36.8) | 0.0806^^ | 69 (33.0) | 45 (32.4) | 24 (34.3) | 0.7815^^ |
Lactic acid baseline (mmol/l), median (Q1,Q3) | 1.8 (1.31, 2.50) | 1.7 (1.32, 2.46) | 1.8 (1.23, 2.75) | 0.4958^ | 2.0 (1.39, 2.67) | 2.0 (1.40, 2.60) | 1.9 (1.30, 2.75) | 0.7388^ |
Platelets count baseline (10^9/l), median (Q1,Q3) | 242.0 (187.00, 316.00) | 244.0 (187.00, 318.00) | 232.0 (178.00, 292.00) | 0.3632^ | 238.0 (182.00, 319.50) | 241.0 (184.00, 331.00) | 228.0 (175.00, 280.00) | 0.1989^ |
Total WBC baseline (10^9/l), median (Q1,Q3) | 9.6 (6.47, 12.80) | 9.7 (6.59, 12.90) | 9.0 (5.40, 12.05) | 0.1128^ | 9.1 (5.80, 12.60) | 9.3 (6.31, 12.80) | 8.7 (5.22, 11.80) | 0.1602^ |
International normalized ratio (INR), median (Q1,Q3) | 1.1 (1.00, 1.20) | 1.1 (1.01, 1.20) | 1.0 (0.99, 1.12) | 0.0050^ | 1.1 (1.00, 1.14) | 1.1 (1.00, 1.15) | 1.0 (0.98, 1.12) | 0.1956^ |
Activated partial thromboplastin time (aPTT) baseline (Seconds), median (Q1,Q3) | 30.0 (26.70, 33.90) | 30.1 (26.70, 33.90) | 29.4 (26.00, 33.80) | 0.4558^ | 29.5 (26.35, 32.90) | 29.3 (26.60, 32.60) | 29.6 (26.00, 33.80) | 0.6378^ |
Total bilirubin (umol/l), median (Q1,Q3) | 9.2 (6.70, 13.70) | 9.2 (6.70, 13.60) | 9.6 (6.90, 15.00) | 0.2665^ | 8.9 (6.80, 14.80) | 8.8 (6.65, 14.65) | 9.5 (7.00, 15.00) | 0.3082^ |
Alanine transaminase (ALT) at admission (U/L), median (Q1,Q3) | 37.0 (25.00, 58.00) | 37.0 (24.00, 57.00) | 38.0 (25.00, 62.00) | 0.7194^ | 35.0 (24.00, 60.00) | 34.5 (23.00, 53.00) | 38.0 (28.00, 62.00) | 0.1851^ |
Aspartate transaminase (AST) at admission (U/L), median (Q1,Q3) | 51.0 (34.00, 75.50) | 51.0 (34.00, 74.00) | 56.0 (36.00, 88.00) | 0.2071^ | 52.0 (35.00, 77.00) | 50.0 (34.00, 72.00) | 57.0 (40.00, 90.00) | 0.0793^ |
Troponin I, median (Q1,Q3) | 32.3 (15.00, 99.05) | 30.0 (14.80, 98.10) | 55.1 (22.00, 113.70) | 0.1550^ | 46.4 (20.40, 148.20) | 31.4 (14.76, 151.00) | 55.8 (26.40, 113.70) | 0.1916^ |
Albumin baseline (gm/l), median (Q1,Q3) | 33.0 (29.00, 36.00) | 33.0 (29.00, 36.00) | 33.0 (31.00, 35.00) | 0.8017^ | 33.0 (30.00, 35.00) | 32.5 (30.00, 35.00) | 33.0 (31.00, 35.00) | 0.3480* |
Hematocrit at admission (L/L),  median (Q1,Q3) | 0.4 (0.35, 0.43) | 0.4 (0.35, 0.43) | 0.4 (0.35, 0.43) | 0.8675^ | 0.4 (0.35, 0.43) | 0.4 (0.36, 0.43) | 0.4 (0.35, 0.43) | 0.9211* |
Creatine phosphokinase (CPK) baseline (U/l), median (Q1,Q3) | 159.5 (65.00, 401.50) | 151.0 (63.00, 402.00) | 197.0 (74.00, 398.00) | 0.2345^ | 197.0 (74.00, 477.00) | 174.5 (63.00, 494.00) | 215.0 (102.00, 398.00) | 0.5771^ |
C-reactive protein (CRP) baseline (mg/l), median (Q1,Q3) | 131.0 (73.80, 202.00) | 133.0 (74.00, 203.00) | 119.5 (66.50, 174.50) | 0.3260^ | 148.0 (83.00, 256.00) | 161.0 (94.00, 275.00) | 121.0 (67.00, 179.00) | 0.0093^ |
ESR at admission (mm/hr), median (Q1,Q3) | 77.5 (51.00, 99.00) | 79.0 (51.00, 99.00) | 68.0 (50.00, 105.00) | 0.5353^ | 71.0 (49.50, 90.50) | 75.5 (49.00, 92.00) | 66.5 (50.00, 89.00) | 0.7781* |
Procalcitonin (ng/ml), median (Q1,Q3) | 0.4 (0.15, 1.12) | 0.4 (0.14, 1.14) | 0.3 (0.19, 1.09) | 0.4899^ | 0.4 (0.18, 1.37) | 0.6 (0.14, 1.39) | 0.3 (0.19, 1.09) | 0.9696^ |
Fibrinogen level baseline (gm/l), median (Q1,Q3) | 5.4 (3.96, 7.00) | 5.5 (3.89, 7.02) | 5.0 (4.21, 6.46) | 0.5645^ | 5.4 (3.91, 6.91) | 5.9 (3.73, 7.02) | 4.8 (4.08, 6.46) | 0.3245^ |
D-dimer level baseline (mg/l), median (Q1,Q3) | 1.2 (0.68, 3.10) | 1.3 (0.69, 3.10) | 1.1 (0.58, 2.48) | 0.2365^ | 1.4 (0.70, 3.29) | 1.5 (0.77, 3.48) | 1.1 (0.58, 3.27) | 0.1428^ |
Ferritin level baseline (ug/l), median (Q1,Q3) | 658.4 (338.15, 1480.40) | 651.0 (335.30, 1448.40) | 878.6 (400.00, 2179.30) | 0.1683^ | 780.6 (359.00, 2106.00) | 757.0 (352.80, 1763.00) | 966.3 (400.00, 2241.50) | 0.5919^ |
Blood glucose level baseline (mmol/l), median (Q1,Q3) | 11.3 (7.90, 16.20) | 11.1 (7.85, 16.10) | 12.5 (8.00, 17.30) | 0.2740^ | 12.3 (8.50, 17.25) | 12.2 (8.50, 17.20) | 12.5 (8.40, 17.30) | 0.9007^ |
Respiratory rate (breath per minute) at admission, median (Q1,Q3) | 28.0 (24.00, 34.00) | 28.0 (24.00, 34.00) | 30.0 (25.00, 35.00) | 0.1598^ | 30.0 (25.00, 35.00) | 30.0 (25.50, 36.00) | 30.0 (25.00, 35.00) | 0.5234* |
Highest heart rate (HR) at admission (BPM), median (Q1,Q3) | 103.0 (91.00, 115.00) | 103.0 (91.00, 115.00) | 101.0 (93.00, 114.00) | 0.9751^ | 105.0 (93.00, 120.00) | 105.0 (91.50, 121.00) | 102.5 (93.00, 114.00) | 0.7523^ |
Pharmacological DVT prophylaxis use during ICU stay, n (%) | 746 (91.9) | 672 (91.3) | 74 (97.4) | 0.0655^^ | 205 (97.6) | 137 (97.9) | 68 (97.1) | 0.7489** |
Patient received nephrotoxic drugs/material during ICU stay, n (%)*$ | 731 (90.5) | 657 (89.8) | 74 (97.4) | 0.0314^^ | 197 (95.2) | 129 (94.2) | 68 (97.1) | 0.3438** |
Comorbidity, n (%) | ||||||||
Atrial fibrillation (A Fib) | 30 (3.7) | 26 (3.5) | 4 (5.3) | 0.4417** | 8 (3.8) | 5 (3.6) | 3 (4.3) | 0.7988** |
Left heart failure | 60 (7.4) | 55 (7.4) | 5 (6.6) | 0.7837^^ | 18 (8.6) | 14 (10.0) | 4 (5.7) | 0.2956^^ |
Right heart failure | 60 (9.6) | 49 (8.9) | 11 (14.5) | 0.1253^^ | 23 (11.0) | 16 (11.4) | 7 (10.0) | 0.7547^^ |
Pulmonary HTN | 122 (19.3) | 100 (18.0) | 22 (28.9) | 0.0231^^ | 59 (28.1) | 41 (29.3) | 18 (25.7) | 0.5873^^ |
Hypertension (HTN) | 452 (55.5) | 411 (55.6) | 41 (53.9) | 0.7805^^ | 111 (52.9) | 76 (54.3) | 35 (50.0) | 0.5575^^ |
Diabetes mellitus (DM) | 474 (58.2) | 427 (57.8) | 47 (61.8) | 0.4943^^ | 114 (54.3) | 72 (51.4) | 42 (60.0) | 0.2398^^ |
Dyslipidemia (DLP) | 179 (22.0) | 157 (21.2) | 22 (28.9) | 0.1225^^ | 51 (24.3) | 30 (21.4) | 21 (30.0) | 0.1721^^ |
Ischemic heart disease (IHD) | 72 (8.8) | 67 (9.1) | 5 (6.6) | 0.4669^^ | 12 (5.7) | 7 (5.0) | 5 (7.1) | 0.5283** |
Chronic kidney disease (CKD) | 53 (6.5) | 48 (6.5) | 5 (6.6) | 0.9775** | 12 (5.7) | 8 (5.7) | 4 (5.7) |  > 0.9999** |
Cancer | 48 (5.9) | 45 (6.1) | 3 (3.9) | 0.4501** | 8 (3.8) | 5 (3.6) | 3 (4.3) | 0.7988** |
Deep vein thrombosis (DVT) | 9 (1.1) | 6 (0.8) | 3 (3.9) | 0.0127** | 3 (1.4) | 1 (0.7) | 2 (2.9) | 0.2174** |
Pulmonary embolism (PE) | 10 (1.2) | 10 (1.4) | 0 (0.0) | 0.3075** | 4 (1.9) | 4 (2.9) | 0 (0.0) | 0.1533** |
Liver disease (any type) | 19 (2.3) | 14 (1.9) | 5 (6.6) | 0.0100** | 7 (3.3) | 2 (1.4) | 5 (7.1) | 0.0297** |
Stroke | 46 (5.6) | 41 (5.5) | 5 (6.6) | 0.7108** | 11 (5.2) | 7 (5.0) | 4 (5.7) | 0.8266** |