Potassium permanganate poisoning and airway oedema

Khaja Mohideen. K. Senthil Kumar*, P. Sasikumar, S. Nirmal Kumar, Sivaagurunathan

Department of Anaesthesiology, Kauvery Hospital, Trichy

Abstract

KMnO4 is irritant to gastrointestinal (GI) system causing ulceration, rarely perforation and massive haemorrhage. Systemic complications can cause acute respiratory distress syndrome, pancreatitis, hepatic and renal damage, methemoglobinemia, disseminated intravascular coagulation and cardiovascular depression. The immediate concern after the ingestion of KMnO4 is the threat of airway oedema which necessitates early endotracheal intubation or even emergency surgical airway. We report here a case of suicidal ingestion of KMnO4 causing airway oedema which was managed conservatively.

Keywords: KMnO4 poisoning, oxidizing agent, airway oedema

Background

Potassium permanganate (KMnO4) is an odourless, crystalline substance readily available over the counter. It has antiseptic and antifungal properties [1]. It is a powerful oxidizing agent producing coagulative necrosis on tissue contact [2]. We report here a case of suicidal ingestion of KMnO4 causing airway oedema.

Case Presentation

A 50 yr old female was brought to our Emergency with history of ingestion of around 5 g of KMnO4 powder. She is a known psychiatric patient for the past 15 years on irregular medications. On arrival she was conscious, oriented and her vitals were stable. She had oedema of the lower lip, tongue and around the angle of mandible (Fig. 1a and b). There were multiple patches of blackish-brown stain on the lower lip. She was not able to vocalise and protrude the tongue out. She had drooling of saliva. Her breathing was normal and there was no stridor. She was shifted to ICU, intubation and tracheostomy sets were kept ready. She was treated with intravenous steroids, glycopyrrolate and adrenaline nebulization (5 ml, 1:1000). Her haemogram, renal function test and liver function tests were normal. Her lower lip and tongue swelling reduced gradually. On day 3 she was able to speak and started taking oral diet. Psychiatric counselling was given.

Discussion

KMnO4 is irritant to gastrointestinal (GI) system. Oxidant damage to intestinal mucosa causes ulceration and rarely perforation. GI erosions can lead to massive haemorrhage. Delayed complications like pyloric stenosis and oesophageal strictures are reported. Systemic toxicity with KMnO4 is due to oxidative injury from free radicals generated by the absorbed permanganate ion. Systemic complications can cause acute respiratory distress syndrome, pancreatitis, hepatic and renal damage, methemoglobinemia, disseminated intravascular coagulation [2-4] and cardiovascular depression [5]. The immediate concern after the ingestion of KMnO4 is the threat of airway oedema which necessitates early endotracheal intubation or even emergency surgical airway [2].

Treatment of KMnO4 poisoning is supportive. Immediate priority is to secure the airway. Steroids and adrenaline nebulisation can decrease airway oedema. In case of severe airway compromise emergency intubation is required. In failed intubation, tracheostomy or cricothyroidotomy may be required [2]. Our patient had oedema of lower lip, tongue and submandibular area. Even though she was not able to vocalise and protrude the tongue, there was no stridor. So she was managed conservatively with steroids and adrenaline nebulisation. The lethal adult dose of KMnO4 is 10 g. Our patient had taken lower dose (5 g). She did not develop any GI or systemic complications. The role of activated charcoal in KMnO4 poisoning is controversial and can be hazardous [1,2]. Hence charcoal was not administered in our patient.

Conclusion

Intravenous steroids and adrenaline nebulisation can be used to treat KMnO4 poisoning with less severe airway compromise keeping emergency intubation and tracheostomy kits ready.

References

Korkut E, et al. Suicidal ingestion of potassium permanganate. World J Emerg Med. 2013;4:73-4.
Agrawal VK, et al. Potassium permanganate toxicity: A rare case with difï¬cult airway management and hepatic damage. Indian J Crit Care Med. 2014;18:819-21.
Middleton SJ, et al. Haemorrhagic pancreatitis: A cause of death in severe potassium permanganate poisoning. Postgrad Med J. 1990;66:657-8.
Ong KL, et al. Potassium permanganate poisoning–a rare cause of fatal self poisoning. J Accid Emerg Med. 1997;14:43-5.
Johnson TB, et al. Unintentional ingestion of potassium permanganate. Pediatr Emerg Care. 2004;20:185-7.

Dr. S. Khaja Mohideen

Anaesthesiologist

Dr. P. Sasi Kumar

Anaesthesiologist

Dr. K. Senthil Kumar

Head of the Department – Anaesthesiology and Toxicology

Potassium permanganate poisoning and airway oedema