P063: CURRENT PERIOPERATIVE MANAGEMENT OF HEREDITARY ANGIOEDEMA
Sapna Desai, MS1, William S Turnage, Chief Anesthesiology2; 1University of Central Florida College of Medicine, 2Flagler Hospital
Case Presentation: A 53 year old Caucasian woman presented to our hospital for lumbar laminectomy and fusion to treat chronic back pain. Her history was remarkable for hereditary angioedema with several previous episodes of severe angioedema that had caused airway compromise. On examination, she was a morbidly obese female with Mallampati 3 airway score and relatively short neck. She had no other significant medical history or findings on examination. Our service was contacted by the patient’s allergist who prescribed a course of plasma derived C1 inhibitor concentrate (Berniert) by intravenous infusion immediately prior to surgery followed by the preemptive intravenous administration of Icatibant (Firazyr), a bradykinin receptor antagonist, immediately prior to tracheal extubation. The patient had been stable on a weekly intravenous course of maintenance C1 inhibitor concentrate (Cinryze), so surgery was scheduled for a day following her usual intravenous infusion of this medication to optimize the level of C1 inhibitor present in plasma.
On the day of surgery, the intravenous infusion of Berniert was administered in the preoperative holding area, then the patient was taken to the operating room where intravenous induction of anesthesia was smoothly accomplished with Propofol and rocuronium. The airway was secured with tracheal intubation facilitated by videolaryngoscopy. At the conclusion of surgery, as the volatile anesthetic was turned off, the prescribed dose of Firazyr was given by slow iv bolus injection. The patient emerged without difficulty and was transported to PACU without any complications noted.
Case Discussion: This patient encounter demonstrated the numerous advances in the care of patients with hereditary angioedema. This disorder is characterized by a genetic deficiency in the inhibitor protein for C1, a component of the complement system active in the inflammatory response that is largely responsible for a direct bactericidal effect. Inherited deficiency of the natural inhibitor protein allows indiscriminate activation of the complement system with resulting soft tissue edema, particularly in the airway. Manipulation of the airway, such as tracheal intubation or dental procedures have been know to provoke angioedema episodes. Previous treatment was predicated on the use of testosterone analogs to stimulate the production of more inhibitor protein in the liver. Fortunately, newer medicines described in this report have improved the care of patients in the perioperative period. The plasma derived C1 inhibitor protein concentrates directly increase the circulating inhibitor protein levels to prevent disinhibited activation of C1, while the bradykinin receptor antagonist directly blocks the receptor responsible for tissue edema formation caused by bradykinin released during the activation of the complement system.
Summary: Anesthesiologists should be familiar with the current treatment of hereditary angioedema as airway interventions can directly stimulate an angioedema crisis. Past prophylactic treatments were relatively ineffective and standard treatments of airway edema such as steroids and antihistamines are not effective. Consultation with a knowledgeable allergist is recommended for optimal management.