title: Transient distal renal tubular acidosis following hump nosed viper bite: Two cases from Sri Lanka.
abstract: Hump-nosed viper (Hypnale hypnale; HNV) is one of the six major snake species in Sri Lanka that cause envenomation. Nephrotoxicity, coagulopathy, and neurotoxicity are wellrecognized features of its envenomation. Type 4 renal tubular acidosis (RTA4) has only once been described previously in this condition, and we report two further cases. Two patients aged 53 and 51 presented following HNV bites with acute kidney injury and microangiopathic hemolytic anemia. Both underwent multiple cycles of hemodialysis until the polyuric phase was reached. Despite polyuria, both patients developed resistant hyperkalemia that needed further hemodialysis. The urinary pH, arterial pH, delta ratio, and transtubular potassium gradient confirmed RTA4. HNV venom has been shown to damage the proximal convoluted tubules in animal studies, but not the distal convoluted tubule, and hence the mechanism of our observation in these two patients is unclear. Unexplained hyperkalemia in recovery phase of HNV bite should raise suspicions of RTA4.
authors.affiliation: Renal Services, University Medical Unit, National Hospital of Sri Lanka, Colombo, Sri Lanka.
authors.forename: Ranga M
authors.initials: RM
authors.lastname: Weerakkody
authors.affiliation: Department of Anesthesiology, National Hospital of Sri Lanka, Colombo, Sri Lanka.
authors.forename: Pushpa N
authors.initials: PN
authors.lastname: Lokuliyana
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka.
authors.forename: Ruchika D
authors.initials: RD
authors.lastname: Lanerolle
mesh_terms: D000141:Acidosis, Renal Tubular; D000818:Animals; D001778:Blood Coagulation Disorders; D006801:Humans; D008875:Middle Aged; D017840:Daboia; D012909:Snake Bites; D013188:Sri Lanka; D014757:Viper Venoms; D017819:Viperidae
chemical_list: D014757:Viper Venoms