Multidrug sedation as a risk factor for deep vein thrombosis in the intensive care unit

Introduction

Critically ill patients are at high risk for deep vein thrombosis (DVT). Among ICU DVT risk factors, the role of muscle relaxant (MR) has been clearly shown [1] but the possible influence of sedative medications (SM) is still under debate. This study was aimed at investigating whether the use of different SM may affect DVT incidence in ICU patients.

Methods

We retrospectively enrolled all patients admitted to a mixed medical-surgical trauma ICU from January 2007 to August 2008 who showed a >72 hours length of stay and were >18 years old; exclusion criteria were DVT at admission and/or within the previous 6 months, thrombophilic profile, high haemorrhagic risk, admission from another ICU. For studying ICU lower limb DVT incidence, compressive ultrasonography (CUS) was performed by three trained ultrasonographers twice a week until discharge. SM and MR administration was registered daily: the drugs considered are presented in Figure 1. MR-treated patients were excluded from statistical analysis; the difference in SM administration in the No DVT group vs the DVT-positive group was assayed by chi-squared test.

Figure 1

Statistical analysis.

Results

Over the period of study, 380 patients were enrolled. Lower limb DVT was diagnosed in 23 of 380 patients, with a DVT incidence of 6.05%. MRs were administered in 121 patients and they were associated with DVT incidence (P < 0.001). Statistical analysis results performed on 259 patients are shown in Figure 1: none of the considered SM resulted to be associated with DVT incidence, nor sedation as a whole or the number of SM administered.

Conclusions

Our study confirms prior findings [1] on the MR role as a DVT risk factor. Nevertheless, SM administration in patients not treated with MR is not associated with increased DVT risk.