Critical Cases - Angioedema
- 40 yo F presents to the ED with lower lip swelling
- PMH of recurrent lip/tongue/pharyngeal swelling suspicious for acquired vs hereditary angioedema
- Has required intubation twice before.
- Today presents with swelling of her lower lip that started about 2 hours ago while she was at work.
- She took 50mg PO benadryl at work but symptoms worsened
- Denies no nausea, vomiting, diarrhea, shortness of breath, wheezing, or rashes.
- No ACEi in medication list.
- No known exposures to allergens or new foods/substances.
BP 126/70 | Pulse 77 | Temp 98 °F (36.7 °C) (Oral) | Resp 20 | SpO2 100% on room air
- Awake, alert, oriented, no distress.
- Swelling in R side of lower face. R sided tongue deviation on tongue protrusion. R sided neck fullness. Uvula and posterior pharynx not swollen. Uvula hanging midline with space on either side. No tracheal deviation present. No difficulty managing secretions.
- Effort normal and breath sounds normal. No stridor. No respiratory distress. She has no wheezes. She has no rales.
- Normal cardiac exam
- Normal abdominal exam
- Normal skin exam
- Angioedema - hereditary vs acquired; vs allergic reaction (no 2 system involvement to suggest anaphylaxis), though no known exposures to allergens.
- Given methylprednisolone, benadryl, famotidine, and C1 esterase inhibitor (human derived Berinert) to treat possible etiologies of symptoms.
- On presentation, airway was not compromised, so ED team decided to closely monitor over the next one hour rather than immediately intubate patient.
- One hour later, called to bedside fter patient had alerted RN that symptoms were progressing.
- On repeat physical exam, there was now swelling in uvula and surrounding tissue bilaterally. The rest of the exam was unchanged.
- Discussed findings with patient and decided to proceed with intubation before critical airway compromise in the setting of worsening symptoms and exam despite maximal medical management.
- Because of potential for significant swelling causing difficult intubation, the ED team decided to proceed with awake intubation with flexible intubating video scope.
- Patient was pre-treated with nebulized lidocaine, viscous lidocaine, glycopyrrolate, and zofran.
- The flexible intubating scope was inserted into patient’s mouth, and once the vocal cords were in clear view, the patient was given a dose of propofol. Once somewhat sedated, the ETT was passed through the vocal cords.
- Admitted to the ICU
- Slowly had improvement of her swelling, and was eventually extubated and discharged home.
- She is still being evaluated for the etiology of her symptoms by rheumatology and immunology
- Hereditary angioedema (HAE) is caused by a deficiency in C1 esterase inhibitor.
- Patients can have low levels of the enzyme (Type 1), or can have dysfunctional form of the enzyme (Type 2).
- Hereditary angioedema is an autosomal dominant disorder, but up to 25% of cases arise from a spontaneous new mutation
- HAE differs from an allergic reaction (mediated by histamine) in that attacks are caused by effects of bradykinin.
- C1 esterase inhibitor usually acts on complement and contact plasma cascades to reduce bradykinin release. When there is decreased or dysfunctional C1E-inhibitor, there is increased amount of bradykinin.
- Bradykinin functions to increased vascular permeability and extravasation, which causes edema.
- Patients can present with submucosal edema in the upper airway and in the bowels (can present with abdominal pain, nausea, vomiting, diarrhea!) and/or with subcutaneous edema under the skin (can be present in face or extremities).
- Treatment options include airway management if necessary and pharmacologic treatments:
C1 esterase inhibitor can be administered directly. Human and recombinant forms exist.
Icatibant is a bradykinin B2 receptor antagonist and acts to reverse effects of bradykinin
Ecallantide is a human plasma kallikrein inhibitor, which inhibits conversion of kiningen to bradykinin.
FFP can also be used, but it contains additional kinins and complement factors beyond what is needed, which creates potential risk of worsening symptoms.
Gower RG, Busse PJ, Aygören-Pürsün E, et al. Hereditary angioedema caused by c1-esterase inhibitor deficiency: a literature-based analysis and clinical commentary on prophylaxis treatment strategies. World Allergy Organ J. 2011;4(2 Suppl):S9-S21. doi:10.1097/WOX.0b013e31821359a2
Rowe, BH., Gaeta, TJ. Anaphylaxis, Allergies, and Angioedema. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide 8th edition. 74-79.