Newsletter
Welcome to the latest edition of The Art of Urgent Care newsletter dedicated to accelerated learning via case-based discussion. Have a great weekend.
Severe Angioedema
A 67 year old man who presented to an Urgent Care clinic with significant tongue swelling which had developed overnight. He had no history of allergies and no history of previous episodes. He had no other symptoms, was undistressed and vitals were stable. Review of medications revealed that he had been on lisinopril for over 10 years. I diagnosed ACEI related angioedema. I have seen this many times and in my experience more commonly affects the lips rather than the tongue. With isolated lip swelling I would usually discharge home and just stop the ACEI. I managed several cases like this as a GP without referral. During my ED experience though I found that there was a lack of familiarity with this situation. This was however the most severe case of isolated tongue swelling that I have seen in my career.
Although skeptical of any benefit I suggested an initial trial of antihistamine and prednisone. This was clearly not anaphylaxis and adrenaline was not inidicated. He was quite dismissive of his symptoms and wanted to go home. He lived alone. I persuaded him to stay in the clinic for an hour for observation since his trajectory was not clear. On review the tongue had become significantly more swollen. He still remained well and undistressed and most importantly he had no signs of airway obstruction. My concern was that he could develop an airway problem and so I insisted on referral to the local ED with an ambulance transfer. His tongue swelling was not quite as bad as that shown in the photo below but it was definitely becoming worrying.
Courtesy of AFP1
Learning Nuggets
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Angioedema may be divided into histamine-mediated(allergic) and bradykinin-mediated (non-allergic) etiologies. This is an essential differentiation, because the treatment for these two entities is entirely different.
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Histamine-mediated angioedema is essentially the same as anaphylaxis and should be treated with adrenaline.
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Bradykinin-mediated angioedema is usually slower in onset but lasts longer. There is usually no urticaria, flushing or pruritus. It does not usually involve other organ systems so does not cause hypotension or wheeze. Laryngeal oedema though is more common than with histamine-mediated angioedema.
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Bradykinin-mediated angioedema involves a viscious spiral due to imbalances between kallekrines and kallekrine inhibitors. This helps to explain why patients with hereditary angioedema or those on ACE inhibitors can be free of symptoms for years.
Courtesy of Internet Book of Critical Care/EMCrit2
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Bradykinin mediated Angioedema causes: medication (ACEI,oestrogens, tPA,tacrolimus,gliptins), hereditary (C1 esterase deficiency), acquired(associated with lymphoproliferative disorders and lupus).
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Risk factors for angioedema:1 African American, smoking, ACEI cough
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A suggested approach to angioedema:2
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Key question: is there stridor? If so there could be laryngeal oedema.
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An Open Evidence search suggests first-line treatment should be on-demand C1-inhibitor concentrate, ecallanitide(kallikrein inhibitor) or icatibant(bradykinin B2 receptor antagnonist). The most evidence supported second-line therapies for refractory cases are fresh frozen plasma, tranexamic acid and recombinant C1-inhibitor.
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In Urgent Care, tranexamic acid is likley to be the only option. It has a good safety profile. Dose = 1g slow IV over 10 mins.
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Airway management with severe angioedema can be very difficut. Laryngeal oedema can prevent use of a SGD and any airway interventions may make the oedema worse. Standard intubation could be technically very difficult/impossible and an RSI with paralytic drugs could induce a CICO (cant intubate, cant oxygenate). If needing intubation: (1) Crashing= ketamine dissociated surgical cricothryotomy(scalpel finger bougie). (2) Non crashing= Awake fiberoptic intubation with second operator ready to do cric.
References
- The Royal Australian College of General Practitioners. ACE inhibitor angioedema [Internet]. Aust Fam Physician. 2013 Dec. Available from: https://www.racgp.org.au/afp/2013/december/ace-inhibitor-angioedema
- Marik PE, Irwin RS. Angioedema [Internet]. EMCrit Project; Available from: https://emcrit.org/ibcc/angioedema/
If you have an interesting case and would like to publish it on this site drop me an email at:
theartofurgentcare@gmail.com
Nuggets of Interest
Mike Cadogan
A favourite question of mine during teaching on Lisfranc injuries is to ask who was Lisfranc. This is Lisfranc the man! An interesting read.
Marco Propersi
This reminded me of a toddler that I saw in my first ED job(some years ago!). The child was brought in by his nanny with a story of falling off a wooden horse. He had a large boggy haematoma over one side of his head. He was well and had a normal GCS. In those days we did a skull XR as an initial investigation and this showed a large parietal skull fracture. PECARN and the Infant Scalp Score are useful tools but I would suggest that from an urgent care perspective any child with a large scalp haematoma should be referred to ED.
