A Surgical Emergency in Disguise

Author: Omar Mohamed, Rania Radwan / Editor: Stephen Sheridan / Codes: DC6, SLO3 / Published: 10/07/2026

A 75-year-old patient presents to the Emergency Department (ED) with a one-day history of progressively worsening pain and swelling of the left lower limb. The pain is severe and disproportionate to the initial visible skin changes. There is no reported history of trauma. The patient describes feeling generally unwell but has not recorded a fever at home.

The past medical history includes atrioventricular (AV) block and hypertension. There is no documented history of diabetes mellitus or peripheral vascular disease.

On arrival, observations demonstrate a heart rate of 101 beats per minute, blood pressure of 108/69 mmHg, temperature of 37.2°C, respiratory rate of 19 breaths per minute, and oxygen saturation (SpO₂) of 95% on room air.

Examination of the left lower limb reveals diffuse swelling and marked tenderness. The skin appears erythematous with areas of violaceous discolouration. Tense bullae are present, with serous fluid oozing from ruptured lesions. Palpation reveals crepitus within the soft tissues. The affected area appears to be extending beyond the margins initially marked on arrival to monitor progression.

Laboratory investigations demonstrate hyponatraemia (serum sodium 127 mmol/ L), elevated lactate of 5.1 mmol/L, markedly raised C-reactive protein (CRP) at 312 mg/L, mild leukocytosis with neutrophilia, and impaired renal function. Plain radiography of the limb reveals gas within the soft tissues.