Hemophilia A

Anesthesia Implications

Anesthesia Implications

Bleeding – this is the big concern. Bleeding can be spontaneous and can persist for long periods of time, even after minor injuries. Spontaneous bleeding is most common in joint cavities. Whether the cause is spontaneous or after injury, the bleeding can be life-threatening. For that reason, surgeries on patients with this condition should take place in a center that can measure AND replace FVIII perioperatively. Arterial access and IM injections should be avoided. Succinylcholine is generally avoided to prevent fasciculations, which may worsen muscle and joint hemorrhage. NSAIDs will further predispose the patient to bleeding.

Positioning – Hematomas or hemarthrosis can be avoided by taking extra care to pad bony prominences and pressure points.

Airway – Where possible, intubation in general should be avoided. If ETT is necessary, avoid nasal intubation and make sure the ETT is lubed. Smooth induction and deep extubation to avoid coughing. Always be mindful of spontaneous or traumatic bleeding that will complicate airway management. Check for blood regularly in the airway. Use soft suction for suctioning the airway.

Factor 8 (FVIII) – This is the primary deficiency in hemophilia A. Emergency bleeding such as in cases of trauma or emergency surgery require a high dose of FVIII concentrate infusion. The amount to be given is calculated like this:

Patient’s body weight (in kg) × desired factor level (IU/dl) × 0.5. For example, if you wanted a 17kg patient to have a level of 100 IU/dL:
17 x 100 x 0.5 = 850 units.

Desired Preoperative Levels:
Major Surgery – 80-100 IU/dl
Minor Surgery – 50-80 IU/dl

Plasma FVIII level increases approximately 2 IU/dl per infused IU/kg of body weight.

Infusion Rate – no greater than 3 mL per minute in Adults, and no greater than 100 units per minute in young children.

Desmopressin (DDAVP) – A great drug for use in patients with mild-moderate hemophilia. This drug is NOT effective in patients with severe hemophilia or high FVIII antibody titers. Desmopressin promotes the release of factor VIII from the endothelium which bridges the missing gap in hemophilia A coagulopathy. Administration: 0.3 ug/kg diluted in 50–100 mL of isotonic saline and infused over 30 min. This will increase the level of FVIII 3-6 times the current level with peak effects at 90 minutes. DDAVP is not approved for use in children less than 2 yrs old or in pregnant women.

Tranexamic Acid (TXA) – useful as an adjunct to stop or prevent bleeding. It should be avoided in patients with hematuria due to obstructive uropathy.

Regional – Guidelines don’t recommend regional anesthesia in these patients. Literature review, however, has shown that neuraxial and peripheral nerve blockade has been performed safely in patients with moderate to severe hemophilia when maintenance of FVIII is within safe ranges.

Pathophysiology

Hemophilia A is a bleeding disorder that is either acquired or an inherited (X-linked recessive) lack of factor VIII. Incidence is 1:5000 male live births.

Labs – labs will typically show HIGH aPTT, normal platelet, normal bleeding times, and normal PTT

Normal plasma levels of FVIII: 50 – 100%, which is equivalent to 50-100 IU/dl
Hemophilia classification:
mild: Greater than 5% but less than 50%
moderate: 1–5%
severe: less than 1%