Causes of hyponatraemia, by initial and retrospective diagnosis
| Cause | Hospital diagnosis n (%) | Retrospective diagnosis n (%) | Odds ratio | p Value |
|---|---|---|---|---|
| SIAD syndrome of inappropriate antidiuresis; TURP, trans-urethral prostatectomy; *Spurious result secondary to taking blood proximal to an intravenous infusion site. †When values of “0” are present 0.5 is added to all of the figures so as to allow an odds ratio and p value to be calculated. | ||||
| No cause found | 51 (49) | 28 (27) | 2.61 | <0.001 |
| Thiazide diuretics | 14 (13) | 19 (18) | 0.70 | 0.15 |
| Other diuretics | 8 (8) | 8 (8) | 1.00 | 1.00 |
| Alcohol related | 6 (6) | 12 (11) | 0.47 | 0.01 |
| SIAD | 21 (20) | 34 (32) | 0.52 | 0.001 |
| Primary polydipsia | 1 (1) | 0 (0) | 3.02 | 0.41 |
| “Drip arm”* | 1 (1) | 1 (1) | 1.00 | 1.00 |
| Dextrose infusion | 1 (1) | 3 (3) | 0.33 | 0.04 |
| Addison’s disease | 0 (0) † | 1 (1) | 0.3 | 0.16 |
| Renal failure | 2 (2) | 1 (1) | 2.02 | 0.48 |
| Heart failure | 0 (0) | 1 (1) | 0.3 | 0.16 |
| Post-TURP | 0 (0) | 1 (1) | 0.3 | 0.16 |
| Hypothyroidism | 1(1) | 1(1) | 1.00 | 1.00 |