TABLE 2.
Baseline Characteristics Categorized by First Serum Sodium Measurement at ICU Admission
| Severe Hyponatremia [Na]first < 125 mmol/L, N = 497 (1.4%) | Mild Hyponatremia [Na]first 125–135 mmol/L, N = 8,068 (22.0%) | Normonatremia [Na]first 135–145 mmol/L, N = 25,965 (70.8%) | Hypernatremia [Na]first > 145 mmol/L, N = 2,130 (5.8%) | |||||
|---|---|---|---|---|---|---|---|---|
| Survivors | Non-survivors | Survivors | Non-survivors | Survivors | Non-survivors | Survivors | Non-survivors | |
| Number of patients | 348 | 149 | 6,190 | 1,878 | 20,926 | 5,039 | 1,411 | 719 |
| Age, mean (sd), yr | 58.9 (15.6) | 60.6 (14.9) | 61.5 (15.2) | 64.6 (13.8) | 60.0 (15.8) | 64.3 (14.5) | 55.5 (17.2) | 60.5 (15.9) |
| Sex, n (%) (female) | 159 (45.7) | 69 (46.3) | 2,372 (38.3) | 695 (37) | 7,577 (36.2) | 1,944 (38.6) | 541 (38.4) | 264 (36.8) |
| Admission type, n (%) | ||||||||
| Pneumonia | 51 (14.7) | 10 (6.7) | 623 (10.1) | 223 (11.9) | 1,456 (7.0) | 485 (9.6) | 186 (13.2) | 95 (13.2) |
| Trauma | 10 (2.9) | 3 (2.0) | 198 (3.2) | 37 (2.0) | 1,635 (7.8) | 240 (4.8) | 201 (14.3) | 77 (10.7) |
| Cardiac arrest | 10 (2.9) | 17 (11.4) | 282 (4.6) | 259 (13.8) | 1,543 (7.4) | 974 (19.3) | 41 (2.9) | 62 (8.6) |
| Sepsis | 35 (10.1) | 18 (12.1) | 560 (9.1) | 257 (13.7) | 884 (4.2) | 387 (7.7) | 129 (9.1) | 85 (11.8) |
| Intracerebral pathology | 24 (6.9) | 11 (7.4) | 379 (24.6) | 179 (9.5) | 2,024 (9.7) | 810 (16.1) | 190 (13.5) | 116 (16.1) |
| Other urgent surgery | 31 (8.9) | 9 (6.0) | 942 (15.2) | 167 (8.9) | 2,557 (12.2) | 512 (10.2) | 131 (9.3) | 53 (7.4) |
| Other elective surgery | 12 (3.4) | 2 (1.3) | 1,622 (26.2) | 164 (8.7) | 6,614 (31.6) | 471 (9.4) | 106 (7.5) | 25 (3.5) |
| Other medical | 174 (50.0) | 78 (52.3) | 1,557 (25.2) | 584 (31.1) | 4,117 (19.7) | 1,140 (22.6) | 420 (29.8) | 198 (27.5) |
| Other | 1 (0.3) | 1 (0.7) | 27 (0.4) | 8 (0.4) | 96 (0.5) | 20 (0.4) | 7 (0.5) | 8 (1.1) |
| Severity of illness | ||||||||
| Acute Physiology and Chronic Health Evaluation-III score, median (IQR) | 74 (58–91.3) | 99 (82–126) | 69 (53–86) | 96 (76–120) | 60 (46–79) | 93 (73–116) | 71 (54–90) | 99 (81–124) |
| Mechanical ventilation at ICU admission, n (%) | 194 (55.7) | 102 (68.5) | 4,599 (74.3) | 1,484 (79.0) | 17,346 (82.9) | 4,399 (87.3) | 1,155 (81.9) | 614 (85.4) |
| Confirmed infection, n (%) | 98 (28.2) | 44 (29.5) | 1,521 (24.6) | 621 (33.1) | 3,030 (14.5) | 1,198 (23.8) | 380 (26.9) | 237 (33.0) |
| Vasoactive drugs at ICU admission, n (%) | 174 (50.0) | 108 (72.5) | 4,071 (65.8) | 1,386 (73.8) | 13,800 (65.9) | 3,768 (74.8) | 810 (57.4) | 517 (71.9) |
| Plasma chloride concentration at ICU admission, mean (sd), mmol/L | 90.5 (8.0) | 94.1 (7.7) | 103.5 (5.7) | 102.4 (5.8) | 107.6 (4.8) | 107.2 (5.5) | 112.6 (7.0) | 113.5 (7.4) |
| Arterial pH at admission, mean (sd) | 7.4 (0.1) | 7.3 (0.1) | 7.4 (0.1) | 7.3 (0.1) | 7.4 (0.1) | 7.3 (0.1) | 7.4 (0.1) | 7.3 (0.1) |
| Comorbidities, n (%) | ||||||||
| Renal insufficiency or dialysis | 30 (8.6) | 22 (14.8) | 613 (9.9) | 244 (13) | 1,161 (5.5) | 476 (9.4) | 77 (5.5) | 43 (6.0) |
| Cirrhosis | 21 (6.0) | 27 (18.1) | 184 (3.0) | 130 (6.9) | 440 (2.1) | 149 (3.0) | 41 (2.9) | 40 (5.6) |
| Cardiovascular disease | 21 (6.0) | 15 (10.1) | 488 (7.9) | 197 (10.5) | 1,459 (7.0) | 427 (8.5) | 55 (3.9) | 39 (5.4) |
| Malignancy (metastasized) | 24 (6.9) | 22 (14.8) | 458 (7.4) | 312 (16.6) | 1,064 (5.1) | 504 (10.0) | 85 (6.0) | 120 (16.7) |
| Length of stay ICU, median (IQR), hr | 78.9 (49.7–168.5) | 97.9 (60.4–217.8) | 88.7 (49.2–167.4) | 123.3 (61.1–253.2) | 86.5 (47.8–170.8) | 126.2 (66.1–264.3) | 148.4 (70.3–336.8) | 129.3 (64.6– 285.7) |
IQR = interquartile range, [Na]first = first serum sodium measurement at ICU admission.