Table 2.
Baseline characteristics
| Variable | Overall (n = 443) | Lower ACAG (n = 342) | Higher ACAG (n = 101) | P value |
|---|---|---|---|---|
| ACAG | 19.75 (16.75–23.50) | 18.50 (16.25–20.50) | 26.75 (25.50-30.25) | < 0.001 |
| Demographics | ||||
| Age, years | 69 (59–80) | 70 (60–81) | 67 (55–78) | 0.12 |
| Men, n (%) | 268 (60.5) | 206 (60.23) | 62 (61.39) | 0.84 |
| Ethnicity, n (%) | ||||
| Asian population | 13 (2.93) | 11 (3.22) | 2 (1.98) | 0.85 |
| White population | 296 (66.82) | 230 (67.25) | 66 (65.35) | |
| Black population | 39 (8.80) | 30 (8.77) | 9 (8.91) | |
| Others | 95 (21.44) | 71 (20.76) | 24 (23.76) | |
| Comorbidities | ||||
| Hypertension, n (%) | 182 (41.08) | 149 (43.57) | 33 (32.67) | 0.05 |
| Diabetes mellitus, n (%) | 133 (30.02) | 96 (28.07) | 37 (36.63) | 0.10 |
| Chronic obstructive pulmonary disease, n (%) | 25 (5.64) | 19 (5.56) | 6 (5.94) | 0.88 |
| Heart failure, n (%) | 166 (37.47) | 126 (36.84) | 40 (39.60) | 0.61 |
| Myocardial infarction, n (%) | 76 (17.16) | 57 (16.67) | 19 (18.81) | 0.62 |
| Malignancy, n (%) | 106 (23.93) | 82 (23.98) | 24 (23.76) | 0.96 |
| Respiratory failure, n (%) | 193 (43.57) | 139 (40.64) | 54 (53.47) | 0.02 |
| Atrial fibrillation, n (%) | 218 (49.21) | 171 (50.00) | 47 (46.53) | 0.54 |
| Septic shock, n (%) | 165 (37.25) | 120 (35.09) | 45 (44.55) | 0.08 |
| Infection positions | ||||
| Blood, n (%) | 17 (3.84) | 14 (4.09) | 3 (2.97) | 0.60 |
| Lung, n (%) | 121 (27.31) | 96 (28.07) | 25 (24.75) | 0.51 |
| Abdomen, n (%) | 110 (24.83) | 94 (27.49) | 16 (15.84) | 0.02 |
| Urinary, n (%) | 74 (16.70) | 55 (16.08) | 19 (18.81) | 0.52 |
| Skin, n (%) | 21 (4.74) | 17 (4.97) | 4 (3.96) | 0.67 |
| Microculture | ||||
| Fungal, n (%) | 73 (16.48) | 51 (14.91) | 22 (21.78) | 0.10 |
| Bacterial, n (%) | 140 (31.60) | 106 (30.99) | 34 (33.66) | 0.61 |
| Bacterial and fungal, n (%) | 52 (11.74) | 39 (11.40) | 13 (12.87) | 0.69 |
| Vital sign | ||||
| Heart rate, beats/min | 94 (81–113) | 92 (81–111) | 101 (90–117) | 0.008 |
| Systolic blood pressure, mmHg | 111 (97–128) | 111 (98–129) | 111 (94–124) | 0.15 |
| Diastolic blood pressure, mmHg | 63 (52–75) | 63 (54–75) | 62 (50–76) | 0.37 |
| Mean arterial pressure, mmHg | 78.67 (68.33–91.33) | 79.33 (68.67–92.67) | 75.33 (67–89) | 0.21 |
| Respiratory rate, times/min | 20 (16.5–25) | 20 (16–25) | 20 (18–27) | 0.22 |
| SPO2, % | 97 (94–100) | 98 (95–100) | 97 (93–99) | 0.002 |
| Temperature, ℃ | 36.72 (36.39–37.11) | 36.78 (36.39–37.17) | 36.61 (36.25-37) | 0.08 |
| Laboratory parameters | ||||
| Neutrophil cells, 109/L | 7.68 (4.69–13.04) | 7.51 (4.66–13.11) | 8.09 (4.71–12.73) | 0.96 |
| Lymphocyte cells, 109/L | 0.88 (0.5–1.43) | 0.88 (0.47–1.36) | 0.93 (0.53–1.74) | 0.47 |
| White blood cells, 109/L | 12.8 (7.6–19) | 12.45 (7.2–18.2) | 14.3 (8.6–21.1) | 0.03 |
| Red blood cells, 109/L | 3.43 (2.83-4) | 3.39 (2.79–3.94) | 3.55 (2.95–4.26) | 0.08 |
| Erythrocyte distribution width, % | 15.6 (14.2–17.8) | 15.5 (14-17.5) | 16.2 (14.5–18) | 0.07 |
| Platelets, 109/L | 145 (95–207) | 145.5 (96–203) | 140 (92–208) | 0.95 |
| Hemoglobin, g/L | 10.3 (8.4–12) | 10.1 (8.4–11.9) | 11 (8.6–12.5) | 0.06 |
| Lymphocyte percentage, % | 7.5 (3.9–12) | 8 (4-12.5) | 6 (3–10) | 0.04 |
| Hematocrit, % | 31.5 (25.7–36.9) | 30.7 (25.3–36.2) | 32.9 (27.4–39.1) | 0.03 |
| Creatinine, mg/dL | 1.4 (0.9–2.2) | 1.2 (0.9–1.7) | 2.3 (1.5-4) | < 0.001 |
| Blood urea nitrogen, mg/dL | 28 (18–45) | 25 (16–37) | 48 (27–72) | < 0.001 |
| Albumin, g/dL | 2.9 (2.5–3.3) | 2.9 (2.5–3.3) | 2.7 (2.4–3.1) | 0.06 |
| Total bilirubin, mg/dL | 3.3 (2.5–4.8) | 3.3 (2.4–4.8) | 3.2 (2.6–4.9) | 0.45 |
| Direct bilirubin, mg/dL | 2.2 (0.9–4.2) | 2.05 (0.8-4) | 2.5 (1.2–4.3) | 0.14 |
| Aspartate aminotransferase, U/L | 110 (45–343) | 85 (39–211) | 350 (115–1952) | < 0.001 |
| Alanine aminotransferase, U/L | 78 (26–246) | 53 (23–182) | 189 (74-1345) | < 0.001 |
| Glucose, mg/dL | 125 (100–161) | 124 (102–158) | 131 (92–165) | 0.84 |
| Triglyceride, mg/dL | 146.5 (90.5–254) | 129.5 (89–245) | 201 (107-341.5) | 0.07 |
| Total cholesterol, mg/dL | 141 (119–184) | 142 (118–183) | 140 (124.5–191) | 0.63 |
| High density lipoprotein cholesterol, mg/dL | 39 (28.5–51) | 39 (29–51) | 39 (26–43) | 0.30 |
| Low density lipoprotein cholesterol, mg/dL | 79 (59–106) | 79 (57–106) | 79 (62–117) | 0.71 |
| Prothrombin time, s | 21.1 (18.6–27.3) | 20.7 (18.5–25.7) | 24.1 (19.1–34.7) | < 0.001 |
| International normalized ratio | 1.9 (1.7–2.5) | 1.9 (1.7–2.4) | 2.2 (1.8–3.3) | < 0.001 |
| Potassium, mmol/L | 4.1 (3.7–4.6) | 4 (3.7–4.4) | 4.6 (4-5.1) | < 0.001 |
| Sodium, mmol/L | 138 (135–141) | 138 (135–141) | 138 (133–140) | 0.12 |
| Calcium, mg/dL | 8.1 (7.6–8.6) | 8.1 (7.7–8.7) | 7.9 (7.3–8.3) | 0.003 |
| Anion gap, mmol/L | 16 (13–19) | 14 (12–17) | 23 (21–27) | < 0.001 |
| Lactate, mmol/L | 2.5 (1.6–4.3) | 2.3 (1.5–3.5) | 5 (2.2-8) | < 0.001 |
| PH | 7.36 (7.27–7.42) | 7.37 (7.3–7.43) | 7.31 (7.19–7.39) | < 0.001 |
| PCO2 | 39 (32–46) | 40 (34–47) | 33.5 (27.5–43.5) | < 0.001 |
| PaO2 | 82 (50–178) | 84 (51–202) | 78.5 (46.5-117.5) | 0.10 |
| Score | ||||
| Sequential Organ Failure Assessment | 3(1–6) | 3(1–5) | 5(1–7) | < 0.001 |
| Treatments | ||||
| Urinary catheter, n (%) | 80 (18.06) | 65 (19.01) | 15 (14.85) | 0.34 |
| Vasopressin, n (%) | 108 (24.38) | 71 (20.76) | 37 (36.63) | 0.001 |
| Ventilation, n (%) | 406 (91.65) | 309 (90.35) | 97 (96.04) | 0.07 |
| Continuous Renal Replacement Therapy, n (%) | 72 (16.25) | 37 (10.82) | 35 (34.65) | < 0.001 |
| Norepinephrine, n (%) | 207 (46.73) | 143 (41.81) | 64 (63.37) | < 0.001 |
| Clinical Outcomes | ||||
| ICU mortality, n (%) | 75 (16.93) | 41 (11.99) | 34 (33.66) | < 0.001 |
| In-hospital mortality, n (%) | 102 (23.02) | 60 (17.54) | 42 (41.58) | < 0.001 |
| 14-day mortality, n (%) | 78 (17.61) | 43 (12.57) | 35 (34.65) | < 0.001 |
| 28-day mortality, n (%) | 108 (24.38) | 63 (18.42) | 45 (44.55) | < 0.001 |
| 90-day mortality, n (%) | 151 (34.09) | 93 (27.19) | 58 (57.43) | < 0.001 |
ACAG Albumin-corrected anion gap