There is sufficient data for thromboprophylaxis

Abstraction: There is sufficient informations for thromboprophylaxis in surgical patients. If we follow these guidelines for medically sick patients it would ensue in giving decoagulants to a big figure of patients. The guidelines are based upon bar of symptomless DVT as an end point. The figure of such patients who develop diagnostic DVT is really little. It would be worthwhile analyzing the hazard factors for DVT in those with diagnostic DVT. We could so aim thromboprophylaxis at a selected group of acutely sick medical patients who would profit most by this intercession.

The ACCP guidelines for thromboprophylaxis have been presented in 2004 and revised in 20081. These guidelines are based on an extended organic structure of literature which has studied the issue of thromboprophylaxis in surgical patients. Therefore the guidelines give really clear and extended recommendations for surgical patients.The ACCP guidelines point out that 70-80 % of fatal PEs really occur in the non surgical scene. Hospitalization for an acute medical unwellness is associated with an eight fold addition in venous thromboembolism. However the guidelines in regard to the patients with general medical upsets are in the chief derived from experience from their surgical opposite numbers. The experience in surgical patients has been sought to be extrapolated to make similar guidelines for the medical patient. These guidelines form the footing for assorted other national guidelines and recommendations.

The ACCP guidelines have been farther simplified from its 2004 guideline to split the patients into three wide groups ( table 1 )

As seen above the guidelines have done off with the descriptive nature of the old hazard group recommendations. The current guidelines have simplified the determination procedure whereby the patients are loosely classified into wide hazard groups based upon their ground for admittance. The guidelines do non urge an individualised marking system as for other conditions such as disseminated intravascular curdling. Such hiting systems for VTE have non been validated and do non adequately identify patients who would non develop VTE.

The absolute Numberss of patients who develop DVT/VTE after admittance for an acute medical status are still little despite the increased hazard of thrombosis as compared to the general population. Diagnostic DVT is seen in & lt ; 1 % of medical patients1. Therefore all medical patients are included in the low and moderate hazard groups of the ACCP guidelines ( table 1 ) . The guidelines estimate that low hazard patients have a less than 10 % hazard of DVT without thromboprophylaxis. The corresponding figure for the moderate hazard patients is 10-40 % 1. This hazard has been arrived at from surveies which have included symptomless DVT ( diagnosed utilizing venography or Doppler ultrasound ) as an end point. This end point is based on the premise that there is a harmony between assymtomatic DVT and clinically of import VTE.

The ACCP 2008 guidelines for medically sick patients are as follows ( presented here verbatim from the published guidelines ) :

“ For acutely sick medical patients admitted to hospital with congestive bosom failure or terrible respiratory disease, or who are confined to bed and have one or more extra hazard factors, including active malignant neoplastic disease, old VTE, sepsis, acute neurologic disease, or inflammatory intestine disease, we recommend thromboprophylaxis with LMWH ( Grade 1A ) , LDUH ( Grade 1A ) , or fondaparinux ( Grade 1A ) . For medical patients with hazard factors for VTE, and for whom there is a contraindication to anticoagulant thromboprophylaxis, we recommend the optimum usage of mechanical thromboprophylaxis with GCS or IPC ( Grade 1A ) . ”

The grounds for usage of LMWH in medical patients are derived mostly from the MEDENOX ( enoxaparin ) , PREVENT ( dalteparin ) and ARTEMIS ( fondaparinux ) tests ( table 2 ) 2

There was no statistically important difference in result among patients having LMWH or LDUH. There was a statistically undistinguished tendency towards better result among patients having LMWH and statistically important 72 % hazard decrease in major hemorrhage when LMWH was used. Heparin causes a important sum of both major and minor bleed ( 0.5 % and 3.7 % ) compared to the placebo group ( 0.2 and 2 % major and minor bleed severally ) . Use of LMWH reduced the hazard of major bleed to 0.3 % .There are no caput to caput tests comparing the assorted LMWH and it is recommended to utilize maker prescribed doses.

The continuance of prophylaxis is still controversial. The consequences of the EXCLAIM test are still awaited. Interim consequences presented as abstracts appear to propose that a longer continuance of prophylaxis would be good in cut downing the hazard of VTE. The ACCP guidelines for thromboprophylaxis continuance are mostly confined to orthopedic patients and urge utilizing prophylaxis for 10-35 days1. In other surgical patients where thromboprophylaxis is recommended, this should be continued till patient is fit to be discharged. This should be true of medical patients as good.

Particular considerations:

The vitamin K adversaries are non recommended on history of a variable pharmacokinetic profile. Medically sick patients have variable nutrient consumption and other accompaniment medicine which would interfere with equal anticoagulation with the unwritten decoagulants. Oral decoagulants have a really narrow curative scope below which they are uneffective and above which there is increased hazard of shed blooding. Similarly acetylsalicylic acid and other antiplatelet agents were used antecedently and still recommended in some guidelines for thromboprophylaxis in surgical patients. However randomized tests have shown them to be inferior to the anticoagulant therapy. They besides increase the hazard of bleed when used in combination with the unwritten decoagulants. Therefore the ACCP guidelines do non urge their usage as thromboprophylaxis. Several patients would hold a compromised nephritic map. Low molecular weight Lipo-Hepins and fondaparinux are excreted through the kidneys and they are expected to bio accumulate in instance of hapless nephritic clearance. This bioaccumulation varies among the assorted low molecular weight Lipo-Hepins and is least with standard contraceptive doses of dalteparin. It is hence recommended to utilize the LMWH with least bioaccumulation or utilize such agents when supervising for their effects is available. In our establishment we recommend LDUH with aPTT monitoring in such patients1.

The ACCP guidelines do non urge everyday thromboprophylaxis in malignant neoplastic disease patients undergoing chemotherapy as there is no grounds that such intercession improves survival. The rates of both symptomless DVT and diagnostic VTE scope from 2-4 % in malignant neoplastic disease patients with indwelling venous catheters1. Larger surveies did non happen any difference in result among those malignant neoplastic disease patients having thromboprophylaxis and those non having thromboprophylaxis. Thus the usage of thromboprophylaxis in patients who have indwelling catheters is non recommended. Use of thromboprophylaxis in those malignant neoplastic disease patients who require surgery or are acutely sick are governed by the general guidelines for perioperative patients and acutely ill medically patients.

Mechanical steps of anticoagulation are an attractive construct as they can be used without fright of bleed. These devices are available as calibrated compaction stockings, intermittent pneumatic pumps or the venous pes pump. These have been found to be effectual in several surveies are a utile adjunct to the anticoagulant therapy. However they have several restrictions to widespread usage. In peculiar, they do non hold any individual criterion for industry or rating of effectivity nor have they been specifically studied in any blinded test. More frequently than non they are used in suitably. Their consequence on pneumonic intercalation and mortality is non known. Therefore their usage is presently recommended1 provided attention givers choose right sizes and educate their patients as respects correct application and attention. Attachment to fabricate guidelines sing usage of single mechanical thromboprophylaxis devices is besides advised.1

What are the deductions of the current ACCP guidelines in attention of medically sick patients?

The medical wards are by and large populated by acutely sick persons who would hold atleast 1 hazard factor as enumerated in the current guidelines. A reasonably increasing proportion of aged patients with indwelling catheters and changing grades of stationariness render most of the patients in medical wards eligible for thromboprophylaxis. Approximately 40 % of medically sick patients have three or more hazard factors for thrombosis2. Data utilizing symptomless DVT as an end point have shown that thromboprophylaxis is a cost effectual and economical intercession to avoid the awful complication of pneumonic intercalation. Therefore the guidelines recommend that medically sick patients at hazard of VTE should have thromboprophylaxis. In malice of presence of guidelines and extended grounds for benefits of thromboprophylaxis the existent usage of thromboprophylaxis in medically sick patients is really low ( table 3 ) .

As seen from the surveies summarised in table 3, big Numberss of patients eligible for thromboprophylaxis based upon eligibility standards in the ACCP guidelines did non have the same. Measures to increase conformity with these guidelines including the usage of audit and feedback, automated computerized reminders to the handling doctor have been suggested1.

So why are we hesitant to utilize thromboprophylaxis in our general medical patients?

Not defying that the guidelines appear to be chiefly directed towards surgical patients, in existent life pattern doctors do non meet many diagnostic DVTs and PEs among admitted patients. The ACCP guidelines are built on the premiss that there is a relationship between symptomless DVTs detected by traditional methods and subsequent diagnostic DVT and PE. The footing of this premiss is based upon surveies in surgical patients and the guidelines acknowledge at the really beginning that farther surveies would be required to prove this hypothesis. It would possibly be unsound to establish the guidelines on an result which might non be clinically relevant.

The absolute figure of patients who develop diagnostic VTE in medically sick patients is really little ( & lt ; 1 % ) 1. Therefore any decrease in VTE even if statistically important is really a really little figure. The figure needed to handle ( NNT ) to forestall one PE is 345 with no consequence on all cause mortality1. Tests measuring cost effectivity of thromboprophylaxis are based upon symptomless DVT results. Therefore there is a demand to critically measure the guidelines for thromboprophylaxis in medically sick patients.6

Which general medical patients should have thromboprophylaxis?

The Sirius trial4 tried to place hazard factors for VTE in the general medical population seen in an outpatient scene. In this population ( defined as patients who had non undergone surgery or application of a plaster dramatis personae to the lower appendages within the 3 hebdomads predating inclusion in survey ) intrinsic factors such as history of VTE, venous inadequacy, chronic bosom failure, fleshiness, immobile standing place, history of more than 3 gestations, and triping factors such as gestation, violent attempt, or muscular injury, impairment of general status, immobilisation, long-distance travel, and infective disease were significantly more frequent in the patients with thrombosis ( odds ratio, & gt ; 1 ; P & lt ; .05 & gt ;

The landmark MEDENOX test was further analysed to place those patients admitted to the wards who would be at an increased hazard of VTE5. In univariate analysis, they were able to place 4 hazard factors, viz. age & gt ; 75years, anterior history of VTE, malignant neoplastic disease and acute infection. Among the acute medical unwellnesss necessitating admittance, respiratory failure, both ague and chronic had the least hazard. Factors such as bosom failure, hormonal therapy, varicose venas, and fleshiness were non associated with an increased hazard of VTE. Age & gt ; 75 old ages was associated with 1.3 times greater hazard of VTE than a 60 twelvemonth old. However on multivariate analysis, the hazard factor with the greatest hazard for VTE was anterior history of VTE and hazard factor with lowest hazard was age & gt ; 75 ( in relation to each other among the 4 hazard factors identified ) . Another interesting determination was that the figure of hazard factors in a given patient did non affair either. Cancer is a hazard factor for thrombosis. As pointed out earlier nevertheless patients with malignant neoplastic disease having chemotherapy and hormonal therapy do non necessitate thromboprophylaxis. Those patients with malignant neoplastic disease confined to bed would necessitate thromboprophylaxis.

Decision

The current ACCP guidelines for thromboprophylaxis in medically sick patients are slightly all encompassing in nature. It recommends the usage of thromboprophylaxis in these patients based on informations derived from surgical patients. These recommendations are based on the premiss that symptomless DVT translates to clinically relevant VTE which as yet remains to be proven in the general medical patient. Thus we may rede thromboprophylaxis in acutely sick medical patients confined to bed based upon current guidelines. The grounds for the same is slightly weaker compared to the robust informations in surgical patients. As seen from analyses of the MEDENOX patients there might be a much more selected group of acutely sick medical patients who would profit most from thromboprophylaxis.

Mentions:

  1. Geerts WH, Bergqvist D, Pineo GF, Heit JA, Samama CM, Lassen MR, Colwell CW. American College of Chest Physicians. Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines ( 8th Edition ) . Chest. 2008 Jun ; 133 ( 6 Suppl ) :381S-453S
  2. Stashenko GJ, Tapson VF. Prevention of venous thromboembolism in medical patients and outpatients. Nat Rev Cardiol. 2009 May ; 6 ( 5 ) :356-63.
  3. Alikhan R, Cohen AT. Heparin for the bar of venous thromboembolism in general medical patients ( excepting shot and myocardial infarction ) . Cochrane Database of Systematic Reviews 2009, Issue 3. Art. No. : CD003747. DOI:10.1002/14651858.CD003747
  4. Samama MM. An epidemiologic survey of hazard factors for deep vena thrombosis in medical outpatients: the Sirius survey. Arch Intern Med. 2000 Dec 11-5 ; 160 ( 22 ) :3415-20.
  5. Alikhan R, Cohen AT, Combe S, Samama MM, Desjardins L, Eldor A, Janbon C, Leizorovicz A, Olsson CG, Turpie AG. MEDENOX Study. Risk factors for venous thromboembolism in hospitalized patients with acute medical unwellness: analysis of the MEDENOX Study. Arch Intern Med. 2004 May 10 ; 164 ( 9 ) :963-8
  6. Miller JA. Rational thromboprophylaxis in medical inmates: non rather at that place yet. MJA 2008 ; 189: 504-506