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Thursday, June 3, 2010

Jehovah Witnesses & Blood Transfusion

Jehovah's Witnesses refuse blood transfusions, including autologous transfusions in which a person has their own blood stored to be used later in a medical procedure, (though some Witnesses will accept autologous procedures such as dialysis or cell salvage in which their blood is not stored) and the use of packed RBCs (red blood cells), WBCs (white blood cells), plasma or platelets.

Accepting a blood transfusion willingly and without regret is seen as a sin. The Witness concerned would no longer be regarded as one of Jehovah's Witnesses.

This refusal to accept blood makes some operations more dangerous and causes some doctors considerable anxiety. Witnesses are willing to absolve doctors of responsibility by signing forms with appropriate wording such as:

As a member of the religious body of Jehovah's Witnesses, I categorically refuse the use of foreign blood or blood components during my surgery. I am aware that the planned and needed procedure thus has a higher risk due to bleeding complications. After receiving thorough explanation particularly about that, I request that the needed surgery be performed without using foreign blood or blood components.

Doctors generally feel that respect for the patient's autonomy requires that this wish should be obeyed. They have sound legal reasons for this too, as to administer blood in the face of refusal by a patient may be unlawful and could lead to criminal and/or civil proceedings.

Many Jehovah's Witnesses carry a signed and witnessed advance directive card absolutely refusing blood and releasing doctors from any liability arising from this refusal.

Cell-free blood products, containing haemoglobin but not red blood cells have recently become available and may be acceptable for some Jehovah's Witnesses.


How do you approach a Jehovah’s Witness patient who needs a transfusion?

  • Avoid coercion and deception that can deny patient’s autonomy and can result in charges of battery
  • While evaluating the need for transfusion in a Jehovah’s Witness, consider the following:
    • Determine whether the patient still believes in Jehovah’s Witness teachings
      • The decision is totally on the individual himself/herself
      • A Jehovah’s Witness family cannot force their religious views upon the patients
      • Check if patients have changed their mind to undergo transfusion in the absence of a church or a family member
      • Thus the discussion should take place in private
      • If the patient does change his or her mind the doctor need to assess if this change might be a consequence of illness impairing the patient’s capacity to decide
      • If patient lacks decision making capacity look to see if the patient has completed an advance directive that can guide the decision-makers
      • Most Jehovah’s Witness carry advance directive cards that explicitly document the individual’s refusal of blood transfusion under any circumstances
        • As a member of the religious body of Jehovah's Witnesses, I categorically refuse the use of foreign blood or blood components during my surgery. I am aware that the planned and needed procedure thus has a higher risk due to bleeding complications. After receiving thorough explanation particularly about that, I request that the needed surgery be performed without using foreign blood or blood components.
      • Make sure that the patient is basing their decisions on specific facts
      • The watchtower lists all unacceptable blood and blood products, and non-blood alternatives that could be used as a substitute for blood
      • Treatment even if deemed by physicians to be life saving, may not be performed on competent patients without their consent
    • Transfusing minors
      • Lifesaving transfusions can be given to minors against parental wishes
      • In such cases proceed by acknowledging the parent’s wishes and informing the parents of the doctor’s responsibility to notify the child welfare authorities (agencies are obligated to provide administrative consent for the treatment) and to transfuse the child in an emergency as required by law
      • Consultation with legal counsel is advisable in such cases

Prognosis of DVT


  • Death occurs in approximately 6% of DVT cases – crucial to detect it early : within 1 month of diagnosis.
  • Recurrence after the first event can be as high as 60% but halved by COMPRESSION STOCKINGS.
  • With anticoagulant therapy, the mortality rate is decreased 5- to 10-fold.
  • DVT recurs in 5% to 10% of patients the year after anticoagulant therapy is discontinued and in 30% of patients after 8 years.
  • Most patients with proximal vein DVT are at long-term risk of chronic venous insufficiency. (30-80%)
  • Approximately 20% of untreated proximal (above the calf) DVTs progress to pulmonary embolism.
  • 10-20% of these PE cases are fatal.

  • Post-phlebitic syndrome (chronic, potentially disabling condition) occurs in 15-50% of patients with deep vein thrombosis (DVT).
  • Within a year or after the 1st attack.
  • Recurrent attack increases the risk by 6 fold.
  • It presents with
  1. Leg oedema
  2. Pain
  3. Nocturnal cramping
  4. Venous claudication
  5. Skin pigmentation
  6. Dermatitis
  7. Ulceration (4-6% - usually on the medial aspect of the lower leg).

Wednesday, June 2, 2010

Differential Diagnosis

Superficial thrombophlebitis
Superficial vein thrombophlebitis is a common inflammatory-thrombotic process that may occur spontaneously or as a complication of medical or surgical interventions. Sterile thrombophlebitis limited to the superficial veins rarely is life threatening, but a thorough diagnostic evaluation is mandatory because many patients with superficial phlebitis also have occult deep vein thrombosis (DVT), which carries high rates of morbidity and mortality.
Patients with superficial thrombophlebitis often give a history of a gradual onset of localized tenderness, followed by the appearance of an area of erythema along the path of a superficial vein. A history of local trauma, prior similar episodes, varicose veins, prolonged travel, hormone use, tobacco use, family history of blood coagulopathies, or enforced stasis may be given. Asking about these risk factors for hypercoagulability should be done, but the absence of identifiable risk factors has no prognostic value.
• Traumatic thrombophlebitis: Ask about trauma, needlesticks, indwelling IV catheters, drug (eg, phenytoin) or hypertonic (10% calcium chloride) solution infusion and sclerotherapy.
• Thrombosed varicose veins: Ask about history of varicose veins


Varicose veins
Varicose veins and telangiectasia (spider veins) are the visible surface manifestations of an underlying problem with reverse venous flow, which is also termed venous insufficiency syndrome. Venous insufficiency syndromes describe venous blood deviating from a normal flow path and flow in a retrograde direction so that fluid accumulates, causing a "congested" leg.
Mild forms of venous insufficiency are merely uncomfortable, annoying, or cosmetically disfiguring, but severe venous disease can produce serious systemic consequences and can lead to loss of life or limb.
Most patients with venous insufficiency have subjective symptoms that may include pain, soreness, burning, aching, throbbing, cramping, muscle fatigue, and restless legs. Over time, chronic venous insufficiency leads to cutaneous and soft tissue breakdown that can be debilitating.


Cellulitis
The word cellulitis literally means inflammation of the cells. It generally indicates an acute spreading infection of the dermis and subcutaneous tissues resulting in pain, erythema, edema, and warmth.
Skin and subcutaneous tissues are involved when microorganisms, typically gram-positive bacteria, invade disrupted skin.

The skin disruption may be obvious, such as a laceration, fissure, or puncture wound. However, cellulitis frequently occurs in areas where no apparent injury exists. This is common in dry and irritated skin where microscopic breaks allow penetration of bacteria.

The infection triggers an inflammatory response that results in the clinically apparent pain, redness, warmth, and swelling.

Muscle Injury/Compartment Syndrome
Compartment syndrome (CS) is a condition in which the perfusion pressure falls below the tissue pressure in a closed anatomic space, with subsequent compromise of tissue circulation and function. Each muscle or muscle group is enclosed in a compartment bound by relatively rigid walls of bone and fascia. The compartments of the lower leg and the volar forearm are particularly prone to developing elevated compartment pressures.

As many as 45% of all cases of CS are caused by tibial fractures. Other causes include any long-bone fracture, vascular injury, compression in the setting of a crush injury, drug overdose, and a tight cast or dressing. Late manifestations of CS include the absence of a distal pulse, extremity paresis, and hypoesthesia. Compartment syndrome (CS) may be the result of either externally applied compressive forces or internally expanding forces. Fractures, vascular injuries, DVT, overexertion, fluid sequestration, or prolonged compression (as from a cast or other cause) may lead to CS. DVT rarely leads to CS, except in the most severe form of DVT, phlegmasia cerulea dolens.

Others:
Achilles tendonitis
Arterial insufficiency
Arthritis
Asymmetric peripheral edema secondary to CHF, liver disease, renal failure, or nephrotic syndrome
Cellulitis, lymphangitis
Extrinsic compression of iliac vein secondary to tumor, hematoma, or abscess
Hematoma
Lymphedema
Muscle or soft tissue injury
Neurogenic pain
Postphlebitic syndrome
Prolonged immobilization or limb paralysis
Ruptured Baker cyst
Stress fractures or other bony lesions
Superficial thrombophlebitis
Varicose veins

Signs and Symptoms of DVT

Signs and symptoms of deep vein thrombosis (DVT)
In about half of all cases, deep vein thrombosis occurs without any noticeable symptoms.
However, the classical symptoms of DVT include:
• Pain in your leg; this can include pain in your ankle and foot. This pain often starts in your calf and can feel like cramping or a "charley horse."
• Swelling in the affected leg, including swelling in your ankle and foot.
• Redness and warmth over the affected area.
• Pain or swelling in your arms or neck. This can occur if a blood clot forms in your arms or neck.
Not all of these symptoms have to occur; one, all, or none may be present with a deep vein thrombosis. The symptoms may mimic an infection or cellulitis (Cellulitis is a diffuse inflammation of connective tissue with severe inflammation of dermal and subcutaneous layers of the skin) of the leg.
In up to 25% of all hospitalized patients, there may be some form of DVT, which often remains clinically unapparent (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 venous tract, which is often tender. Physical examination is unreliable for excluding the diagnosis of deep vein thrombosis.
Historically, healthcare providers would try to elicit a couple of clinical findings to make a diagnosis. Dorsiflexion of the foot (pulling the toes towards the nose, or Homans' sign) and Pratt's sign (squeezing the calf to produce pain), have not been found effective in making a diagnosis.
It is vital that the possibility of pulmonary embolism be included in the history, as this may warrant further investigation (see pulmonary embolism).
If you develop signs or symptoms of a pulmonary embolism — a life-threatening complication of deep vein thrombosis — seek medical attention immediately.
The warning signs of a pulmonary embolism include:
 Unexplained sudden onset of shortness of breath
 Chest pain or discomfort that worsens when you take a deep breath or when you cough
 Feeling lightheaded or dizzy, or fainting
 Coughing up blood
 A sense of anxiety or nervousness

Tests For DVT

Physical examination
• Homans' test: Dorsiflexion of foot elicits pain in posterior calf. Warning: it must be noted that it is of little diagnostic value and is theoretically dangerous because of the possibility of dislodgement of loose clot.
• Pratt's sign: Squeezing of posterior calf elicits pain.
D-dimer testing
• The D-dimer test has an important role in the diagnostic approach to deep venous thrombosis (DVT). D-dimer fibrin fragments are present in fresh fibrin clot and in fibrin degradation products of cross-linked fibrin. Monoclonal antibodies specific for the D-dimer fragment are used to differentiate fibrin-specific clot from non–cross-linked fibrin and from fibrinogen. These specific attributes of the D-dimer antibodies account for their high sensitivity for venous thromboembolism.
• D-dimer level may be elevated in any medical condition where clots form. D-dimer level is elevated in trauma, recent surgery, hemorrhage, cancer, and sepsis. Many of these conditions are associated with higher risk for DVT. The D-dimer assays have low specificity for DVT; therefore, they should only be used to rule out DVT, not to confirm the diagnosis of DVT.
• D-dimer levels remain elevated in DVT for about 7 days. Patients presenting late in the course, after clot organization and adherence have occurred, may have low levels of D-dimer. Similarly, patients with isolated calf vein DVT may have a small clot burden and low levels of D-dimer that are below the analytic cut-off value of the assay. This accounts for the reduced sensitivity of the D-dimer assay in the setting of confirmed DVT.
• Many different D-dimer assays are available, with varying sensitivities and specificities. The assays are not standardized. They incorporate different monoclonal antibodies to the D-dimer fragment. Results may be reported quantitatively or qualitatively. Different units may be used; some assay results are reported as fibrinogen equivalent units (FEU) and others in nanograms per milliliter (ng/mL). The results of one assay cannot be extrapolated to another.
• Most studies have confirmed the clinical utility of D-dimer testing, and most clinical algorithms incorporate their use. Physicians should know their hospital's D-dimer assay.
• All D-dimer assays have been evaluated in various validation studies that determine the assay's sensitivity, specificity, and negative predictive value (NPV). Unfortunately, fewer management studies have been conducted to determine the safety of withholding anticoagulant therapy on the basis of a negative test result. Furthermore, the NPV of a specific assay falls as the pretest probability of the study population at risk for DVT increases. An assay with a sensitivity of 80% has an NPV of 97.6% in a low-risk patient. However, the NPV of the same assay is only 33% in high-risk patients with a pretest probability of 90% for DVT.
• Traditional enzyme-linked immunosorbent assays (ELISAs), although accurate, are time-consuming and not practical for use in the ED. A rapid ELISA assay (VIDAS) with high sensitivity was validated in a large European trial. In that study a negative VIDAS D-dimer assay essentially ruled out DVT. All patients with a negative D-dimer result did not require further diagnostic testing with ultrasonography.
• The older qualitative latex agglutination assay is not accurate and should not be used for making treatment decisions in patients with suspected DVT. Newer latex-enhanced immunoturbidimetric and immunofiltration assays have high sensitivity and are available.
• A rapid qualitative RBC agglutination assay (SimpliRED) is available. It is sensitive for proximal vein DVT but less so for calf vein DVT. A large study confirmed that, in low-risk patients with low pretest probability for DVT, a negative SimpliRED D-dimer result rules out DVT. Ultrasonography was not required in these patients.
• Current evidence strongly supports the use of a D-dimer assay in the clinical algorithm of suspected DVT. A negative D-dimer assay result rules out DVT in patients with low-to-moderate risk (Wells DVT score <2). A negative result also obviates surveillance and serial testing in patients with moderate-to-high risk and negative ultrasonographic findings.
Results
• A negative D-dimer assay result rules out DVT in patients with low-to-moderate risk and a Wells DVT score less than 2.
• All patients with a positive D-dimer assay result and all patients with a moderate-to-high risk of DVT (Wells DVT score >2) require a diagnostic study (duplex ultrasonography).
Other blood tests
• Protein S, protein C, antithrombin III, factor V Leiden, prothrombin 20210A mutation, antiphospholipid antibodies, and homocysteine levels can be measured.
• Deficiencies of these factors or the presence of these abnormalities all produce a hypercoagulable state. These are rare causes of DVT.
• Laboratory investigations for these abnormalities are primarily indicated when DVT is diagnosed in patients younger than 50 years, when there is a confirmed family history of a hypercoagulable state or a familial deficiency, when venous thrombosis is detected in unusual sites, and in the clinical setting of warfarin-induced skin necrosis.