Publication date: Jun 10, 2026
To investigate factors associated with mortality in critically ill COVID-19 patients at 3640 m above sea level (m. a.s. l.), focusing on the interaction between altitude-induced secondary erythrocytosis and virus-induced hyperviscosity. We conducted a retrospective cohort study of 59 adult patients with severe ARDS admitted to the ICU in La Paz, Bolivia. Severe ARDS was defined using altitude-adapted criteria. Non-survivors exhibited significantly higher median hematocrit (53. 4% vs 49. 7%; p = 0. 0001) and D-dimer (29,729 vs 16,521 ng/mL; p = 0. 0001) compared to survivors. An “APACHE II paradox” was observed, as survivors had significantly higher admission scores than non-survivors (24 vs 17; p = 0. 01). While initial ventilatory mechanics were comparable (14. 3 vs 14. 1 cm H₂O; p = 0. 81), non-survivors experienced exclusive complications, including pneumothorax (24. 2%) and pulmonary embolism (18. 2%). Hyperviscosity, exacerbated by altitude-induced erythrocytosis, is a primary factor associated with mortality in this environment. Traditional severity scores may not adequately stratify risk in high-altitude contexts, highlighting the need for altitude-specific protocols focusing on rheological control.
| Concepts | Keywords |
|---|---|
| 16521ng | ARDS |
| 3640m | COVID-19 |
| Bolivia | High altitude |
| Erythrocytosis | Hyperviscosity |
| High | Mortality |
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | critically ill |
| disease | MESH | COVID-19 |
| disease | MESH | erythrocytosis |
| disease | MESH | pneumothorax |
| disease | MESH | pulmonary embolism |