Table 1.
Characteristics of patients.
| Severe hypoNa Na < 125 |
Moderate hypoNa 125 ≤ Na < 130 |
Mild hypoNa 130 ≤ Na < 135 |
Borderline hypoNa 135 ≤ Na < 138 |
No dysnatremia 138-142 |
Borderline hyperNa 142 > Na ≥ 145 |
Mild hyperNa 145 > Na ≥ 150 |
Moderate hyperNa 150 > Na ≥ 155 |
Severe hyperNa Na > 155 |
P value* | |
|---|---|---|---|---|---|---|---|---|---|---|
| N = 349 | N = 693 | N = 2005 | N = 2258 | N = 3865 | N = 1078 | N = 633 | N = 143 | N = 101 | ||
| Patient characteristics | ||||||||||
| Male gender | 197 (56.4%) | 392 (56.6%) | 1211 (60.4%) | 1381 (61.2%) | 2391 (61.9%) | 649 (60.2%) | 380 (60%) | 81 (56.6%) | 60 (59.4%) | 0.1846 |
| Age (yrs) | 62 (51-75) | 63 (49.5-75.5) | 63 (51-76) | 62 (49-75) | 63 (49-76) | 62 (48-75) | 65 (53-76) | 67 (46-77) | 64 (57-77) | 0.0358 |
| Weight (kg) | 67 (56-80) | 69 (58-81) | 68 (58.4-80) | 71 (60-83) | 70.3 (60-83) | 70 (60-82) | 70 (59.7-81) | 65 (59.7-80) | 69 (55-80) | < .0001 |
| SOFA score [13] | 6 (3-8) | 6 (4-9) | 5 (3-8) | 5 (3-7) | 5 (2-7) | 5 (3-9) | 7 (4-10) | 8 (5-11) | 8 (6-12) | < .0001 |
| SAPS II score [14] | 56 (45-66) | 57 (47-66) | 55 (44-65) | 51 (41-61) | 50 (39-60) | 53 (43-65) | 57 (47-69) | 63 (52-73) | 66 (54-78) | < .0001 |
| Underlying condition | ||||||||||
| Chronic kidney disease | 20 (5.7%) | 50 (7.2%) | 142 (7.1%) | 121 (5.4%) | 225 (5.8%) | 61 (5.7%) | 30 (4.7%) | 7 (4.9%) | 4 (4%) | 0.2031 |
| Immunocompromised | 55 (15.8%) | 143 (20.6%) | 366 (18.3%) | 343 (15.2%) | 458 (11.8%) | 128 (11.9%) | 93 (14.7%) | 12 (8.4%) | 12 (11.9%) | < .0001 |
| Main symptom at admission | ||||||||||
| Acute respiratory failure | 65 (18.6%) | 189 (27.3%) | 529 (26.4%) | 580 (25.7%) | 893 (23.1%) | 244 (22.6%) | 151 (23.9%) | 21 (14.7%) | 20 (19.8%) | 0.0003 |
| Coma | 68 (19.5%) | 74 (10.7%) | 216 (10.8%) | 296 (13.1%) | 661 (17.1%) | 236 (21.9%) | 138 (21.8%) | 51 (35.7%) | 28 (27.7%) | < .0001 |
| Septic shock | 33 (9.5%) | 98 (14.1%) | 294 (14.7%) | 225 (10%) | 343 (8.9%) | 107 (9.9%) | 76 (12%) | 18 (12.6%) | 9 (8.9%) | < .0001 |
| Shock (other) | 42 (12%) | 86 (12.4%) | 226 (11.3%) | 218 (9.7%) | 327 (8.5%) | 122 (11.3%) | 84 (13.3%) | 16 (11.2%) | 16 (15.8%) | < .0001 |
| Acute renal failure | 47 (13.5%) | 78 (11.3%) | 128 (6.4%) | 101 (4.5%) | 108 (2.8%) | 39 (3.6%) | 25 (3.9%) | 7 (4.9%) | 7 (6.9%) | < .0001 |
| Trauma | 0 | 1 (0.1%) | 13 (0.6%) | 19 (0.8%) | 66 (1.7%) | 11 (1%) | 6 (0.9%) | 5 (3.5%) | 1 (1%) | < .0001 |
| Treatments at ICU admission | ||||||||||
| Antibiotics | 190 (54.4%) | 446 (64.4%) | 1278 (63.7%) | 1236 (54.7%) | 1903 (49.2%) | 567 (52.6%) | 387 (61.1%) | 90 (62.9%) | 75 (74.3%) | < .0001 |
| Central venous catheter | 125 (35.8%) | 312 (45%) | 824 (41.1%) | 867 (38.4%) | 1446 (37.4%) | 459 (42.6%) | 342 (54%) | 79 (55.2%) | 60 (59.4%) | < .0001 |
| Vasoactive drugs | 107 (30.7%) | 259 (37.4%) | 671 (33.5%) | 650 (28.8%) | 1041 (26.9%) | 350 (32.5%) | 277 (43.8%) | 65 (45.5%) | 49 (48.5%) | < .0001 |
| Mechanical ventilation | 124 (35.5%) | 253 (36.5%) | 840 (41.9%) | 1026 (45.4%) | 1846 (47.8%) | 605 (56.1%) | 363 (57.3%) | 93 (65%) | 62 (61.4%) | < .0001 |
| Renal replacement therapy | 53 (15.2%) | 113 (16.3%) | 212 (10.6%) | 217 (9.6%) | 307 (7.9%) | 96 (8.9%) | 83 (13.1%) | 11 (7.7%) | 19 (18.8%) | < .0001 |
| Outcome | ||||||||||
| DFLST | 16 (4.6%) | 49 (7.1%) | 108 (5.4%) | 93 (4.1%) | 171 (4.4%) | 78 (7.2%) | 51 (8.1%) | 11 (7.7%) | 7 (6.9%) | < .0001 |
| ICU mortality | 66 (18.9%) | 160 (23.1%) | 381 (19%) | 360 (15.9%) | 551 (14.3%) | 220 (20.4%) | 176 (27.8%) | 48 (33.6%) | 49 (48.5%) | < .0001 |
| Day-30 mortality | 83 (23.8%) | 183 (26.4%) | 446 (22.2%) | 430 (19.0%) | 642 (16.6%) | 242 (22.5%) | 203 (32.1%) | 57 (39.9%) | 55 (54.5%) | < 0.001 |
| Hospital mortality | 89 (25.5%) | 201 (29.0%) | 483 (24.1%) | 458 (20.3%) | 693 (17.9%) | 264 (24.5%) | 215 (34.0%) | 58 (40.6%) | 57 (56.4%) | < .0001 |
*Comparison across different subclasses of serum sodium concentration at ICU admission. The data are reported as medians (IQR). SOFA, Sequential Organ Failure Assessment, which can range from 0 to 24; SAPS II, Simplified Acute Physiology Score version II, which can range from 0 to 155; DFLST, decision to forgo life-sustaining treatments.