Methylene blue in patients with severe pulmonary hypertension

Clostridium perfringens sepsis complicated by right ventricular cardiogenic shock

Clostridium perfringens sepsis has been ascribed a dismal prognosis when associated with massive intravascular haemolysis. We present a 71-year-old woman's fatal case which was compounded by isolated right ventricular cardiogenic shock. In this context, combined use of transthoracic echocardiography and pulmonary artery catheter monitoring is able to yield an individualized hemodynamic resuscitation. We discuss key aspects related to right and left heart mechanical efficiency, hypothesize as to the pulmonary hypertension mechanism of our case and set to emphasize a physiologically based framework for right ventricular failure hemodynamic management.

[Not Available]

BACKGROUND

Methylene blue is used in medical practice for various reasons. Recent findings point to a potential interaction with serotonin reuptake inhibitors (SRIs) that could lead to serotonergic toxicity.

OBJECTIVE

To describe the risk of serotonergic toxicity associated with the interaction between methylene blue and SRIs.

DATA SOURCES

Relevant publications were searched systematically via MEDLINE (1946 to March 21, 2013) and Embase (1974 to 2013, week 11) with the following search terms: "methylene blue", "methylthioninium", "monoamine oxidase inhibitors", "serotonin reup-take inhibitors", and "serotonin syndrome". No restrictions were applied in relation to the indication for methylene blue or the language of publication. The reference lists of identified articles were also searched.

STUDY SELECTION AND DATA EXTRACTION

Eighteen case reports and 2 case series were identified for inclusion. To date, no randomized controlled trials have been published.

DATA SYNTHESIS

The first case report indicating suspicion of an interaction between methylene blue and SRIs was published in 2003. Seventeen other case reports describing the same type of interaction have been published since then. The 2 case series provided data from about 325 parathyroidectomies in which methylene blue was used for staining. The 17 patients who experienced central nervous system toxicity were all taking SRIs in the preoperative period.

CONCLUSION

When administered in combination with SRIs, methylene blue may lead to serotonergic toxicity at doses as low as 0.7 mg/kg. Methylene blue would seem to have monoamine oxidase A inhibitory properties. Precautions should be taken to avoid this interaction. [Publisher's translation].

Accidental injection of patent blue dye during gynaecological surgery: Lack of knowledge constitutes a system error

The authors report a case in which an intravenous injection of Patent Blue V dye instead of Indigo Carmine was given during routine gynaecological surgery. The patient presented with temporary arterial (spurious) desaturation and skin discoloration over a 48-hour period. Pharmacological differences between these dyes are described. Root cause analysis based on the ALARM (Association of Litigation and Risk Management) model is presented. The authors emphasise that use of this model should not be limited solely to describing and correcting well known systems errors such as working conditions or teamwork and communication. Furthermore, they conclude that insufficient knowledge must also be recognised as a systems error and as such should be sought out and corrected using similar strategies to those used to discover other contributory factors, without allocation of blame to any individual.