TABLE 3.
Description of Serum Sodium Over Entire ICU Stay for All Patients With Mild Hyponatremia or Normonatremia at ICU Admission and a Subgroup of Patients With an Increase of Serum Sodium During the First 48 Hours of ICU Admission (Difference Between Mean of Sodium Measurements 24–48 hr After ICU Admission and First Serum Sodium at Admission) > 5 mmol/L
| Descriptives | Mild hyponatremia [Na]first 125–135 mmol/L, N = 8,068 | p | Normonatremia [Na]first 135–145 mmol/L N = 25,965 | p | ||
|---|---|---|---|---|---|---|
| Survivors | Nonsurvivors | Survivors | Nonsurvivors | |||
| All patients | ||||||
| Number of patients | 6,190 | 1,878 | 20,926 | 5,039 | ||
| [Na]first, mean (sd), mmol/L | 131.9 (2.3) | 131.4 (2.5) | < 0.01 | 138.4 (2.4) | 138.7 (2.5) | < 0.01 |
| Δ48 hr-[Na], mean (sd), mmol/L | 2.9 (3.6) | 3.8 (4.0) | < 0.01 | 0.0 (3.4) | 1.3 (4.3) | < 0.01 |
| [Na]max, mean(sd), mmol/L | 138.5 (5.5) | 140.5 (6.8) | < 0.01 | 141.9 (4.6) | 144.7 (6) | < 0.01 |
| Time to [Na]max, median (IQR), hr | 31.9 (14.6–62.9) | 40.3 (20.8–109.0) | < 0.01 | 20.3 (6.5–48.0) | 31.4 (11.2–78.2) | < 0.01 |
| V-[Na]max, median (IQR), mmol/L/24 hr | 3.6 (1.9–6.6) | 3.5 (1.9–6.6) | 0.37 | 2.1 (0.4–5.1) | 2.8 (1.1–6.2) | < 0.01 |
| Subgroup Δ48 hr-[Na] > 5 mmol/L | ||||||
| Number of patients | 1,685 | 650 | 1,606 | 817 | ||
| [Na]first, mean (sd), mmol/L | 130.9 (2.6) | 130.6 (2.7) | 0.02 | 137.8 (2.4) | 138.4 (2.1) | < 0.01 |
| Δ48 hr-[Na], mean (sd), mmol/L | 7.5 (2.4) | 8.0 (3.4) | 0.01 | 6.8 (2.2) | 8.1 (3.8) | < 0.01 |
| [Na]max, mean (sd), mmol/L | 141.9 (5.4) | 143.4 (6.3) | < 0.01 | 147.4 (4.9) | 150.1 (5.8) | < 0.01 |
| Time to [Na]max, median (IQR), hr | 39.5 (27.6–65.5) | 41.2 (26.5–82.5) | 0.22 | 36.7 (25.6–53.9) | 37.7 (25.1–55.2) | 0.67 |
| V-[Na]max, median (IQR), mmol/L/24 hr | 5.2 (3.7–7.8) | 5.5 (3.6-9.0) | 0.09 | 5.2 (3.8–7.7) | 6.0 (4.2–10.3) | < 0.01 |
IQR = interquartile range, [Na]first = first serum sodium measurement at ICU admission, [Na]max = maximum serum sodium measurement during entire ICU admission, V-[Na]max = velocity of reaching [Na]max during entire ICU stay, Δ48 hr-[Na] = difference between mean of sodium measurements 24–48 hr after ICU admission and [Na]first.
Data are presented separately for survivors and nonsurvivors. Data are shown for all patients and separately for a subgroup of patients with a Δ48 hr-[Na] > 5 mmol/L. Continuous data are presented as mean with sd and median with interquartile range (IQR). The p values represent the difference between survivors and nonsurvivors, p < 0.05 was considered statistically significant. For patients with severe hyponatremia or hypernatremia at ICU admission, see Supplementary Table 2 (http://links.lww.com/CCM/G542).