Recommendations for venesection in adults with cyanotic congenital heart disease
| Symptom | Action |
|---|---|
| No symptoms of hyperviscosity | Venesection not indicated |
| Symptoms of hyperviscosity | |
| Haematocrit > 65, no dehydration | Isovolumic venesection (400–500 ml) |
| Haematocrit 60–65, iron replete | Isovolumic venesection (400–500 ml) |
| Haematocrit < 65, iron deficient | Low dose iron treatment; closely monitoring haematocrit |