Intravenous mannitol is being considered to break an attack of acute primary angle closure in a 70-year-old woman. Which comorbidity is the MOST important contraindication to its use?

• A Controlled type 2 diabetes mellitus
• B Previous uncomplicated cataract surgery in the fellow eye
• C Chronic stable angina
• D Congestive cardiac failure ✓

Explanation

Mannitol acts as an osmotic agent, drawing water from the vitreous into the intravascular compartment and rapidly expanding circulating volume before diuresis begins. This sudden volume load can precipitate pulmonary edema in patients with cardiac failure. Diabetes is a relative concern only with glucose-containing hyperosmotics such as glycerol given orally, and angina or a previous cataract extraction do not preclude osmotic therapy.

Reference: Parsons' Diseases of the Eye, 23rd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.