# Associations of RBC counts and incidence of DVT in patients with spinal cord injury: a five year observational retrospective study

## TL;DR

This study found that red blood cell counts in spinal cord injury patients are linked to deep vein thrombosis risk, with a protective effect below a certain threshold and increased risk above it.

## Contribution

The study identifies a U-shaped relationship between RBC counts and DVT incidence in SCI patients, offering new insights for prevention strategies.

## Key findings

- RBC counts below 4.56 × 10^12/L are protective against DVT in SCI patients.
- A 1.00 × 10^12/L increase in RBC counts correlates with a 45% decrease in DVT incidence.
- RBC counts above 4.56 × 10^12/L increase DVT risk in this population.

## Abstract

The role of red blood cell (RBC) counts as potential independent risk factors for deep vein thrombosis (DVT) in patients with spinal cord injury (SCI) remains uncertain. This study aims to clarify the associations between RBC counts and DVT incidence among this population.

A retrospective analysis was performed on 576 patients with SCI admitted to the rehabilitation medicine department from January 1, 2017 to December 31, 2021. After exclusions, 319 patients were analyzed, among which 94 cases of DVT were identified.

Mode of injury, D-dimer and anticoagulant therapy were significant covariates (P < 0.05). Age, fibrinogen, D-dimer, anticoagulant therapy and American Spinal Cord Injury Association impairment scale (AIS) grades were associated with RBC counts and DVT incidence (P < 0.05). Adjusting for these factors, a 1.00 × 10^12/L increase in RBC counts correlated with a 45% decrease in DVT incidence (P = 0.042), revealing a “U” shaped relationship with a pivot at 4.56 × 10^12/L (P < 0.05).

RBC counts below 4.56 × 10^12/L serve as a protective factor against DVT, while counts above this threshold pose a risk. These findings could inform the development of DVT prevention strategies for patients with SCI, emphasizing the need for targeted monitoring and management of RBC counts.

The online version contains supplementary material available at 10.1186/s13018-024-04838-1.