Impact of practice change in reducing venous thromboembolism in neurocritical overweight patients: 2008-2014

Analysis of venous thromboembolism in neurosurgical patients undergoing standard versus routine ultrasonography

Routine screening of high-risk asymptomatic trauma or surgical patients for venous thromboembolism (VTE) is controversial. Studies suggest against screening while others recognize that some patients at high risk may benefit. The purpose of this pilot study is to evaluate the benefit of routine screening using doppler ultrasonography for the early detection of deep venous thrombosis (DVT) in post-operative neurosurgical patients. This was a quasi-experimental study at a major academic tertiary care medical center. A total of 157 adults underwent cranial or spinal surgical interventions from March through August 2017 and received either standard screening (n = 104) versus routine ultrasonography screening (n = 53). There was no significant difference in incidence of DVT between the two groups: 11 (11%) in the standard screening group versus 5 (9%) in the routine screening group, p = 0.823. Upper and lower extremity ultrasonography was performed in 43 (41%) of the standard screening group versus 53 (100%) in the routine screening group, p < 0.001. DVT was identified in nearly one of every 6 ultrasonography screenings in the standard screening group versus 27 ultrasonography screenings required to identify one DVT in the routine screening group. There were the same number of screenings for upper extremity ultrasonography, but they did not yield or detect DVT; instead only superficial, untreatable, DVTs were reported. Total cost to diagnose one DVT, including screening and labor, averaged $13,664 in the standard group versus $56,525 in the routine group. Routine screening in neurosurgical patients who received VTE prophylaxis was not associated with lower incidence of VTE and mortality attributed to PE. Thus, routine screening may not be cost effective to prevent complications from DVT incidence.

Assessment of the Relationship between Body Mass Index and Incidence of Venous Thromboembolism in Hospitalized Overweight and Obese Patients

STUDY OBJECTIVE

To assess whether a positive linear association exists between body mass index (BMI) and incidence of venous thromboembolism (VTE) in overweight and obese hospitalized patients.

DESIGN

Single-center retrospective observational cohort study.

SETTING

Large academic tertiary care medical center.

PATIENTS

A total of 1452 adults hospitalized between January 1, 2013, and December 31, 2014, who weighed more than 100 kg and had a BMI of 25 kg/m² or greater on admission, and received heparin subcutaneously for VTE prophylaxis. Patients were categorized into four subgroups based on World Health Organization BMI classification: overweight (141 patients), obese class I (305 patients), obese class II (324 patients), and obese class III (682 patients).

MEASUREMENTS AND MAIN RESULTS

The primary outcome was occurrence of VTE in each subgroup; all-cause mortality and length of hospital stay were secondary outcomes. A linear trend test did not show an association between occurrence of VTE and BMI of 25 kg/m² or greater. VTE occurred in 7 (5%) of 141 patients in the overweight group, 5 (2%) of 305 in the obese class I group, 8 (3%) of 324 in the class II group, and 18 (3%) of 682 in the class III group (p=0.573). In addition, no linear association was noted between all-cause mortality or length of hospital stay and BMI of 25 kg/m² or greater. Overall mortality was 10% (146/1452 patients). Ten deaths (7%) occurred in the overweight group, 45 (15%) in the obese class I group, 38 (12%) in the obese class II group, and 53 (8%) in the obese class III group (p=0.067). The median length of hospital stay was 5 days (interquartile range 3-9, p=0.122) for all patients.

CONCLUSION

In overweight and obese hospitalized patients who weighed more than 100 kg and had a BMI of 25 kg/m² or greater, the incidence of VTE did not increase incrementally with increasing severity of obesity.