Venous thromboembolism counseling & advice for travelers: Difference between revisions
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Both these studies were performed among populations that were younger (mean age 35–40 years) and healthier than the general population and are not, therefore, generalizable to a higher-risk population. | Both these studies were performed among populations that were younger (mean age 35–40 years) and healthier than the general population and are not, therefore, generalizable to a higher-risk population. | ||
==Treatment== | |||
==Reference== | ==Reference== | ||
{{reflist|2}} | {{reflist|2}} | ||
Revision as of 17:20, 18 April 2012
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Venous thromboembolism Microchapters |
Editors-in-Chief: C. Michael Gibson, M.S., M.D. Associate Editor-In-Chief: Ujjwal Rastogi, MBBS [1]
Overview
Venous thromboembolism (VTE) consists of 2 related conditions: 1) deep vein thrombosis (DVT) and 2) pulmonary embolism (PE). DVT occurs when a deep vein is partially or completely blocked by a blood clot, most commonly in the legs. The clot may break off and travel to the vessels in the lung, causing a life-threatening PE.
Historical Perspective
VTE associated with air travel was first described in the early 1950s.[1] Previous studies have shown a 2- to 4-fold increased risk of VTE after air travel.[2]
Risk Factors
The risk of venous thrombosis and air travel was examined in the WRIGHT (World Health Organization Research Into Global Hazards of Travel) project. Several factors have been associated with an increased risk for developing VTE:
| Risk factors for developing VTE include:[3] |
| Recent major surgery |
| Paralytic spinal cord injury |
| Multiple trauma |
| Malignancy |
| Congestive heart failure or respiratory failure |
| Hormone replacement therapy, oral contraceptive |
| Previous venous thromboembolism |
| Inherited hypercoagulable condition |
| Acquired hypercoagulable condition |
| Pregnancy |
| Age >40 years |
| Obesity |
| Immobility |
| Male gender |
A retrospective cohort study[4] shows that the risk of VTE increased with flight duration and with the number of times the employee flew during an 8-week period; the risk of VTE tripled in employees who went on 5 or more long-haul (>4 hours) flights. Each extra flight increased the risk of VTE 1.4-fold. The risk of VTE was highest in the first 2 weeks after a long-haul flight and gradually decreased to baseline after 8 weeks.
Incidence
A recent meta-analysis investigating the association between travel and VTE found a 2-fold higher risk for VTE in travelers compared with nontravelers. Significant variability was noted in the outcomes of the studies included in the review. This variability was directly related to the method used to select the comparison group in each study. When studies that used people referred for VTE evaluation as comparisons were excluded from the meta-analysis, the remaining studies showed a 3-fold higher risk of VTE associated with travel. The risk for VTE increased with travel duration. Each 2-hour increase in travel duration resulted in an 18% higher risk for VTE.
A retrospective cohort study done with 2,499 healthy Dutch commercial pilots showed the incidence of VTE to be 0.3 per 1,000 person-years.When the data were adjusted for age and sex, the rate was not different from that in the general Dutch population.
The second study was among 8,755 employees of several international companies and organizations. The overall incidence of VTE after air travel was 1.4 per 1,000 person-years.[4] The incidence of VTE within 8 weeks of a long-haul flight (>4 hours) was 3.2 per 1,000 person-years compared with an incidence of 1.0 per 1,000 person-years in employees who did not fly. The absolute risk of VTE per flight more than 4 hours was 1 per 4,656 flights. Incidence was also higher in employees with a BMI more than 25 kg/m2 and those with height less than 1.65 m (5 ft 5 in) or more than 1.85 m (6 ft 1 in).
Both these studies were performed among populations that were younger (mean age 35–40 years) and healthier than the general population and are not, therefore, generalizable to a higher-risk population.
Treatment
Reference
- ↑ WRIGHT HP, OSBORN SB (1952). "Effect of posture on venous velocity, measured with 24NaCl". Br Heart J. 14 (3): 325–30. PMC 479460. PMID 14944721. Retrieved 2012-04-18. Unknown parameter
|month=ignored (help) - ↑ HOMANS J (1954). "Thrombosis of the deep leg veins due to prolonged sitting". N. Engl. J. Med. 250 (4): 148–9. doi:10.1056/NEJM195401282500404. PMID 13119864. Retrieved 2012-04-18. Unknown parameter
|month=ignored (help) - ↑ Anderson FA, Spencer FA (2003). "Risk factors for venous thromboembolism". Circulation. 107 (23 Suppl 1): I9–16. doi:10.1161/01.CIR.0000078469.07362.E6. PMID 12814980. Retrieved 2012-04-18. Unknown parameter
|month=ignored (help) - ↑ 4.0 4.1 Kuipers S, Cannegieter SC, Middeldorp S, Robyn L, Büller HR, Rosendaal FR (2007). "The absolute risk of venous thrombosis after air travel: a cohort study of 8,755 employees of international organisations". PLoS Med. 4 (9): e290. doi:10.1371/journal.pmed.0040290. PMC 1989755. PMID 17896862. Retrieved 2012-04-18. Unknown parameter
|month=ignored (help)