Zanzibar Yam Poisoning - A Rare and Debilitating Condition

Abstract

Background: Zanzibar Yam poisoning is not common worldwide, much less so in Singapore. This species of plant has been imported for experimental purposes but have since been propagated in the wild locally due to its efficient asexual reproduction. Toxins produced are highly alkaloid and was used in Africa as poison for fishing and cross bow hunting. We describe a case of intentional ingestion and poisoning of this high toxic plant. Case details: A 67-year-old male with past history of diabetes mellitus presented to the Emergency Department after ingestion of said plant which he harvested with vomiting and diarrhoea. Other than transaminitis and hyperlactataemia, his physical examination was unremarkable. ICU admission was warranted with worsening lactatemia upon further observation. A tumultuous 12 day ICU stay ensued during which he quickly developed severe rhabdomyolysis with hyperlactataemia resulting in acute kidney injury (AKI) and eventual anuria. This was initially treated with IV hydration as well as IV N-acetylcysteine, sodium thiosulphate and hydroxocobalamin but quickly progressed to Renal Replacement Therapy. Intubation was necessary on day 2 of ICU stay due to worsening acidosis and 2 further reintubation attempts were needed due to flash pulmonary oedema and hypercarbia induced loss of consciousness respectively. He also developed adjustment disorder which required psychiatric evaluation and treatment. He was eventually discharged after successful extubation and correction of underlying biochemical abnormalities to the community hospital for continuation of IV antibiotics and renal replacement. Conclusions: Zanzibar yam poisoning is a rare event and management is largely supportive from initial resuscitation to subsequent intensive care management. When severe, this can lead to significant end organ damage, be it temporary or permanent. More awareness needs to be raised to prevent further such incidents from happening.