Talk:Jacopo Torriti and Deep vein thrombosis: Difference between pages
(Difference between pages)
Content deleted Content added
m BOT - adding adding WPVA banner |
|||
Line 1:
{{Infobox_Disease |
Name = {{PAGENAME}} |
Image = |
Caption = |
DiseasesDB = 3498 |
ICD10 = |
ICD9 = {{ICD9|453.40}} |
ICDO = |
OMIM = |
MedlinePlus = |
eMedicineSubj = med |
eMedicineTopic = 2785 |
MeshID = D020246 |
}}
: ''This article is about Deep-vein thrombosis. For other uses of DVT, see [[DVT (disambiguation)]].''
'''Deep-vein thrombosis''' (also known as '''deep-venous thrombosis''' or '''DVT''' and colloquially as '''economy class syndrome''') is the formation of a [[blood clot]] ("thrombus") in a [[deep vein]]. It commonly affects the [[leg]] [[vein]]s, such as the [[femoral vein]] or the [[popliteal vein]] or the deep veins of the pelvis. Occasionally the veins of the [[arm]] are affected (known as ''[[Paget-Schrötter disease]]''). [[Thrombophlebitis]] is the more general class of pathologies of this kind.
==Signs and symptoms==
There may be no symptoms referrable to the ___location of the DVT, but the classical symptoms of DVT include [[Pain and nociception|pain]], [[swelling]] and redness of the [[leg]] and dilatation of the surface veins. In up to 25% of all hospitalized patients, there may be ''some'' form of DVT, which often remains clinically inapparent (unless [[pulmonary embolism]] develops).
There are several techniques during physical examination to increase the detection of DVT, such as measuring the circumference of the affected and the contralateral limb at a fixed point (to objectivate [[edema]]), and palpating the [[vein|venous]] tract, which is often tender. Physical examination is unreliable for excluding the diagnosis of deep vein thrombosis.
A careful history has to be taken considering ''risk factors'' (see below), including the use of estrogen-containing methods of [[hormonal contraception]], recent long-haul flying, and a history of [[miscarriage]] (which is a feature of several disorders that can also cause thrombosis). A family history can reveal a [[genetic disorder|hereditary]] factor in the development of DVT.
It is vital that the possibility of pulmonary embolism be included in the history, as this may warrant further investigation (''see'' [[pulmonary embolism]]).
'''''Complications ''''' As a complication, [[post-thrombotic syndrome]] can develop. Post-phlebitic syndrome occurs in 10% of patients with deep vein thrombosis (DVT). It presents with leg oedema, pain, nocturnal cramping, venous claudication, skin pigmentation, dermatitis and ulceration (usually on the medial aspect of the lower leg).
In phlegmasia alba dolens, the leg is pale and cool with a diminished arterial pulse due to spasm. It usually results from acute occlusion of the iliac and femoral veins due to DVT.
In phlegmasia cerulea dolens, there is an acute and nearly total venous occlusion of the entire extremity outflow, including the iliac and femoral veins. The leg is usually painful, cyanosed and oedematous. Venous gangrene may supervene.
==Diagnosis==
The [[gold standard (test)|gold standard]] is ''intravenous venography'', which involves injecting a peripheral [[vein]] of the affected limb with a [[contrast agent]] and taking [[X-ray]]s, to reveal whether the [[vein|venous]] supply has been obstructed. Because of its invasiveness, this test is rarely performed.
[[Impedance plethysmography]] can also be used as a non-invasive alternative.
===Probability scoring===
In [[2006]], Scarvelis and Wells overviewed a set of clinical criteria for DVT,<ref>{{cite journal | author = Scarvelis D, Wells P | title = Diagnosis and treatment of deep-vein thrombosis. | journal = CMAJ | volume = 175 | issue = 9 | pages = 1087-92 | year = 2006 | id = PMID 17060659. [http://www.cmaj.ca/cgi/content/full/175/9/1087 Free Full Text] }}</ref> on the heels of a widely adopted set of clinical criteria for pulmonary embolism.<ref>Neff MJ. ACEP releases clinical policy on evaluation and management of pulmonary embolism. ''American Family Physician''. 2003; '''68'''(4):759-?. Available at: [http://www.aafp.org/afp/20030815/practice.html http://www.aafp.org/afp/20030815/practice.html]. Accessed on: December 8, 2006.</ref><ref>{{cite journal | author = Wells P, Anderson D, Rodger M, Ginsberg J, Kearon C, Gent M, Turpie A, Bormanis J, Weitz J, Chamberlain M, Bowie D, Barnes D, Hirsh J | title = Derivation of a simple clinical model to categorize patients probability of pulmonary embolism: increasing the models utility with the SimpliRED D-dimer. | journal = Thromb Haemost | volume = 83 | issue = 3 | pages = 416-20 | year = 2000 | id = PMID 10744147}}</ref>
'''Wells score or criteria''':
(Possible score -2 to 9)
:1) Active cancer (treatment within last 6 months or palliative) -- 1 point
:2) Calf swelling >3cm compared to other calf (measured 10cm below tibial tuberosity) -- 1 point
:3) Collateral superficial veins (non-varicose) -- 1 point
:4) Pitting edema (confined to symptomatic leg) -- 1 point
:5) Swelling of entire leg - 1 point
:6) Localized pain along distribution of deep venous system -- 1 point
:7) Paralysis, paresis, or recent cast immobilization of lower extremities -- 1 point
:8) Recently bedridden > 3 days, or major surgery requiring regional or general anesthetic in past 12 weeks -- 1 point
:9) Previously documented DVT -- 1 point
:10) Alternative diagnosis at least as likely -- Subtract 2 points
'''Interpretation''':
: Score of 2 or higher - deep vein thrombosis is likely. Consider imaging the leg veins.
: Score of less than 2 - deep vein thrombosis is unlikely. Consider blood test such as [[d-dimer]] test to further rule out deep vein thrombosis.
===Imaging the leg veins===
Compression [[medical ultrasonography|ultrasound]] scanning of the leg veins, combined with duplex measurements (to determine blood flow), can reveal a [[blood clot]] and its extent (i.e. whether it is below or above the [[knee]]).
===Blood tests===
In a low-probability situation, current practice is to commence investigations by testing for [[D-dimer]] levels. This cross-linked [[fibrin degradation product]] is an indication that [[thrombosis]] is occurring, and that the [[blood clot]] is being dissolved by [[plasmin]]. A low D dimer level should prompt other possible diagnoses (such as a ruptured [[Baker's cyst]], if this has not been considered as part of the history).
Other blood tests usually performed at this point are:
* [[complete blood count]]
* Primary [[coagulation]] studies: [[prothrombin time|PT]], [[APTT]], [[Fibrinogen]]
* [[liver enzyme]]s
* [[renal function]] and [[electrolyte]]s
==Therapy==
* [[Thrombolysis]] is generally reserved for extensive clot, e.g. an iliofemoral thrombosis. Although a [[meta-analysis]] of [[randomized controlled trials]] by the [[Cochrane Collaboration]] shows improved outcomes with [[thrombolysis]],<ref name="pmid15495034">{{cite journal |author=Watson L, Armon M |title=Thrombolysis for acute deep vein thrombosis |journal=Cochrane Database Syst Rev |volume= |issue= |pages=CD002783 |year= |id=PMID 15495034}}</ref> there may be an increase in serious bleeding complications.
* [[Anticoagulation]] is the usual treatment for DVT. In general, patients are initiated on a brief course (i.e., less than a week) of [[heparin]] treatment while they start on a 3- to 6-month course of [[warfarin]] (or related [[vitamin K]] inhibitors). [[Low molecular weight heparin]] (LMWH) is preferred,<ref name="pmid0000">{{cite journal |author=Snow V et al |title=Management of Venous Thromboembolism: A Clinical Practice Guideline from the American College of Physicians and the American Academy of Family Physicians |journal=Ann Intern Med |volume= 146 |issue= 3|pages= |year= 2007 | url = http://www.annals.org/cgi/content/full/0000605-200702060-00149v1}}</ref> though unfractionated [[heparin]] is given in patients who have a contraindication to LMWH (e.g., renal failure or imminent need for invasive procedure). In patients who have had ''recurrent DVTs'' (two or more), anticoagulation is generally "life-long." The [[Cochrane Collaboration]] has meta-analyzed the risk and benefits of prolonged anti-coagulation.<ref name="pmid16437432">{{cite journal |author=Hutten B, Prins M |title=Duration of treatment with vitamin K antagonists in symptomatic venous thromboembolism |journal=Cochrane Database Syst Rev |volume= |issue= |pages=CD001367 |year= |id=PMID 16437432}}</ref>
* Elastic compression stockings should be routinely applied.<ref name="pmid0000">.</ref> The stockings in almost all trials were ''stronger than routine anti-embolism stockings'' and created either 20-30 mm Hg or 30-40 mm Hg. Most trials used knee-high stockings. A [[meta-analysis]] of [[randomized controlled trials]] by the [[Cochrane Collaboration]] showed reduced incidence of post-phlebitic syndrome.<ref name="pmid14974060">{{cite journal |author=Kolbach D, Sandbrink M, Hamulyak K, Neumann H, Prins M |title=Non-pharmaceutical measures for prevention of post-thrombotic syndrome |journal=Cochrane Database Syst Rev |volume= |issue= |pages=CD004174 |year= |id=PMID 14974060 | doi = 10.1002/14651858.CD004174.pub2}}</ref> The [[number needed to treat]] is quite potent at 4 to 5 patients need to prevent one case of post-phlebitic syndrome.<ref name="pmid17003920">{{cite journal |author=Kakkos S, Daskalopoulou S, Daskalopoulos M, Nicolaides A, Geroulakos G |title=Review on the value of graduated elastic compression stockings after deep vein thrombosis |journal=Thromb Haemost |volume=96 |issue=4 |pages=441-5 |year=2006 |id=PMID 17003920}}</ref>
* [[Inferior vena cava filter]] reduces pulmonary embolism<ref name="pmid9459643">{{cite journal |author=Decousus H, Leizorovicz A, Parent F, Page Y, Tardy B, Girard P, Laporte S, Faivre R, Charbonnier B, Barral F, Huet Y, Simonneau G |title=A clinical trial of vena caval filters in the prevention of pulmonary embolism in patients with proximal deep-vein thrombosis. Prévention du Risque d'Embolie Pulmonaire par Interruption Cave Study Group |journal=N Engl J Med |volume=338 |issue=7 |pages=409-15 |year=1998 |id=PMID 9459643}}</ref> and is an option for patients with an absolute contraindiciation to anticoagulant treatment (e.g., cerebral hemorrhage) or those rare patients who have objectively documented recurrent PEs while on anticoagulation, an [[inferior vena cava filter]] (also referred to as a ''[[Greenfield filter]]'') may prevent pulmonary embolisation of the leg clot. However these filters are themselves potential foci of thrombosis,<ref name="pmid16009794">{{cite journal |author= |title=Eight-year follow-up of patients with permanent vena cava filters in the prevention of pulmonary embolism: the PREPIC (Prevention du Risque d'Embolie Pulmonaire par Interruption Cave) randomized study |journal=Circulation |volume=112 |issue=3 |pages=416-22 |year=2005 |id=PMID 16009794}}</ref> IVC filters are viewed as a temporizing measure for preventing life-threatening pulmonary embolism.
==Prophylaxis (Prevention)==
[[Clinical practice guidelines]] by the American College of Chest Physicians (ACCP) provide recommendations on DVT prophylaxis in hospitalized patients <ref name="pmid15383478">Geerts WH, Pineo GF, Heit JA, Bergqvist D, Lassen MR, Colwell CW, Ray JG. Prevention of venous thromboembolism: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy.
Chest. 2004 Sep;126(3 Suppl):338S-400S. http://www.chestjournal.org/cgi/content/full/126/3_suppl/338S PMID 15383478</ref>.
===General Medical Inpatients===
Regarding general medical inpatients the guidelines state, "In acutely ill medical patients who have been admitted to the hospital with congestive heart failure or severe respiratory disease, or who are confined to bed and have one or more additional risk factors, including active cancer, previous VTE, [[sepsis]], acute neurologic disease, or inflammatory bowel disease, we recommend prophylaxis with LDUH (Grade 1A) or LMWH (Grade 1A)<ref name="pmid15383478">.</ref>."
Since publication of the ACCP guidelines, an additional [[randomized controlled trial]] <ref name="pmid16431185">Lederle FA, Sacks JM, Fiore L, Landefeld CS, Steinberg N, Peters RW, Eid AA, Sebastian J, Stasek JE Jr, Fye CL. The prophylaxis of medical patients for thromboembolism pilot study. Am J Med. 2006;119:54-9. PMID 16431185</ref> and [[meta-analysis]] <ref name="pmid17310052">Dentali F, Douketis JD, Gianni M, Lim W, Crowther MA. [http://annals.org/cgi/content/full/146/4/278 Meta-analysis: anticoagulant prophylaxis to prevent symptomatic venous thromboembolism in hospitalized medical patients]. Ann Intern Med. 2007;146:278-88. PMID 17310052</ref> including the trial have been published. The [[meta-analysis]] concluded " Anticoagulant prophylaxis is effective in preventing symptomatic venous thromboembolism during anticoagulant prophylaxis in at-risk hospitalized medical patients. Additional research is needed to determine the risk for venous thromboembolism in these patients after prophylaxis has been stopped." With regards to which patients are at risk, most studies in the meta-analysis were of patients with [[New York Heart Association Functional Classification]] (NYHA) III-IV heart failure. Regarding patients at lesser risk of DVT, the trial above<ref name="pmid16431185">.</ref> and an earlier trial<ref name="pmid">Gardlund B. Randomised, controlled trial of low-dose heparin for prevention of fatal pulmonary embolism in patients with infectious diseases. The Heparin Prophylaxis Study Group. Lancet. 1996 May 18;347(9012):1357-61. PMID 8637340</ref> are relevant yet inconclusive.
===Surgery Patients===
In patients who have undergone [[surgery]], [[low molecular weight heparin]]s (LMWH) are routinely administered to prevent thrombosis. LMWH can only currently be administered subcutaneously by injection. Prophylaxis for pregnant women who have a history of thrombosis may be limited to LMWH injections or may not be necessary if their risk factors are mainly temporary.
Early and regular ambulation (walking) is a treatment that predates anticoagulants and is still recognized and used today. Walking activates the body's muscle pumps, increasing venous velocity and preventing [[stasis]]. [[Intermittent pneumatic compression]] (IPC) machines have proven protective in bed- or chair-ridden patients at very high risk or with contraindications to heparins. IPC machines use air bladders that are wrapped around the thigh and/or calf. The bladders alternately inflate and deflate, squeezing the muscles and increasing blood velocity by as much as 500%. IPC machines have been proven effective on knee and hip surgery patients (a population with a risk as high as 80% with no prophylactic treatment) of developing DVT and PE.
Alternatively, between 150-300mg of aspirin can be taken.
There is clinical evidence to suggest that wearing compression socks while travelling also reduces the incidence of thrombosis in people on long haul flights. A randomised study in 2001 compared two sets of long haul airline passengers, one set wore travel compression hosiery the others did not. The passengers were all scanned and blood tested to check for the incidence of DVT. The results showed that asymptomatic DVT occurred in 10% of the passengers who did not wear compression socks. The group wearing compression had no DVTs. The authors concluded that wearing elastic compression hosiery reduces the incidence of DVT in long haul airline passengers. J Scurr et. al. 2001 Lancet.<ref>Scurr JH, Machin SJ, Bailey-King S, Mackie IJ, McDonald S, Smith PD. Frequency and prevention of symptomless deep-vein thrombosis in long-haul flights: a randomised trial. ''[[The Lancet|Lancet]] 2001;12(9267):1485-9. PMID 11377600.</ref>.See also [[Economy class syndrome]]
==Pathogenesis==
{{main|Thrombosis}}
Many factors are involved in the formation of a thrombus (clot). [[Virchow's triad]] is a group of 3 factors known to affect clot formation: rate of flow, the consistency (thickness) of the blood, and qualities of the vessel wall. Among the risk factors are advanced age, obesity, infection, immobilization, female sex, use of [[oral contraceptive]]s, tobacco usage and [[air travel]] ("[[economy class syndrome]]", a combination of immobility and relative dehydration) are some of the better-known causes.<ref>{{cite journal | author = Tsai A, Cushman M, Rosamond W, Heckbert S, Polak J, Folsom A | title = Cardiovascular risk factors and venous thromboembolism incidence: the longitudinal investigation of thromboembolism etiology. | journal = Arch Intern Med | volume = 162 | issue = 10 | pages = 1182-9 | year = 2002 | id = PMID 12020191}}</ref> [[Thrombophilia]] (tendency to develop thrombosis) often expresses itself with recurrent thromboses.
It is recognised that thrombi usually develop first in the calf veins, "growing" in the direction of flow of the vein. DVTs are distinguished as being above or below the [[popliteal]] vein. Very extensive DVTs can extend into the [[iliac vein]]s or the [[inferior vena cava]]. The risk of pulmonary embolism is higher in the presence of more extensive clots.
==Epidemiology==
DVTs occur in about 1 per 1000 persons per year. About 1-5% will die from the complications (i.e. [[pulmonary embolism]]).
DVT is much less common in the pediatric population. About 1 in 100,000 people under the age of 18 experiences deep vein thrombosis, possibly due to a child's high rate of heartbeats per minute, relatively active lifestyle when compared with adults, and fewer comorbodities (e.g. malignancy).
==See also==
*[[Venogram (medical)]]
==References==
<references/>
==External links==
*[http://www.clotcare.com/clotcare/dvt.aspx Deep Vein Thrombosis (DVT) Prevention, Treatment, Diagnosis, & Related Issues] - ClotCare.com
*[http://www.dvt.net/ Deep Vein Thrombosis (DVT) Blood Clot Prevention, Treatment, and More] - DVT.net
*[http://www.whonamedit.com/synd.cfm/1924.html Paget-von Schrötter disease] - whonamedit.com
*[http://www.emedicine.com/emerg/topic122.htm DVT] - emedicine.com
*[http://www.anticoagulationeurope.org/welcome.html AntiCoagulation Europe] - AntiCoagulation Europe is a charity providing information and advice to people on oral anticoagulation therapy
*[http://www.preventdvt.org/ Prevent DVT Coalition ]
*[http://www.jscurr.com/StudySummary.htm J Scurr Lancet study summary]
*[http://www.mediuk-travel.co.uk/clinical_evidence.html mediUK DVT prevention during travel, the clinical evidence]
{{Hematology}}
[[Category:Hematology]]
[[Category:Angiology]]
[[Category:Vascular surgery]]
[[nl:Diep-veneuze trombose]]
[[pt:Trombose venosa profunda]]
| |||