A case report of topical local anaesthetic cream inducing methaemoglobinaemia with an over-the-counter medication.

What Is Known And Objective: Methaemoglobinaemia is an altered state of haemoglobin caused by a variety of therapeutics which impairs tissue oxygenation. There are numerous cases in the literature of methaemoglobinaemia induced iatrogenically in a hospital environment. This is a case of methaemoglobinaemia induced by an over-the-counter topical local anaesthetic in a patient with widespread skin lesions.

Agreement between bicarbonate measured on arterial and venous blood gases.

Objective: This study aims to determine the extent of agreement between venous and arterial bicarbonate for a group of emergency department patients with respiratory or metabolic illness requiring blood gas analysis as part of their evaluation.

Methods: This prospective study of patients who were deemed by their treating doctor to require an arterial blood gas analysis to determine their ventilatory or acid-base status, compared bicarbonate on an arterial and a venous sample taken as close to simultaneously as possible. Data were analysed using bias (Bland-Altman) methods.

Venous pCO(2) and pH can be used to screen for significant hypercarbia in emergency patients with acute respiratory disease.

This prospective study of patients with acute respiratory illness or potential ventilatory compromise compared pCO(2) and pH on an arterial and a venous blood sample with the aims of determining whether venous pH and pCO(2) can replace arterial values in the management of patients with acute respiratory disease and to determine whether there is a cut-off level of venous pCO(2) that can accurately screen for significant hypercarbia (pCO(2) > 50 mm Hg). Data were analyzed using bias plot and receiver operator characteristic (ROC) curve methods. There were 196 sample-pairs analyzed; 56 (29%) had significant hypercarbia.