Essay Example on Oxalic Acid or oxalate ethanedioic acid a colorless odorless and Crystalline

Oxalic Acid or oxalate ethanedioic acid a colorless odorless and crystalline powder is a toxic and dangerous substance in its concentrated and pure form It is usually used as a kitchen cleanser stain and rust remover or bleaching laundry agent In the Philippines it is readily available and can be easily bought from sidewalk vendors and sari sari stores in small retail plastic packets at 30g per pack It can be easily mistaken as sugar or salt and its availability makes it a common agent for suicide Acute oxalic acid poisoning has earned a number of deaths in the past years Two died from milk tea poisoning in 2015 which was found to contain oxalic acid In 2011 two pupils died and 44 others were hospitalized in a certain elementary school after eating an oxalic acid laced food 1 In the 2013 Annual Report of the National Poison Management and Control Center NPMCC household cleaning agents 16 was cited as the most common toxic agent involved in acute poisoning with ingestion 86 as the major route of exposure 2 NPMCC also reported 6 cases of oxalic acid ingestion in the year 2017 and 10 cases in the year 2016 mostly non accidental 

3 A review of available literature from other countries yielded few studies Only certain countries sell oxalic acid readily as it is usually used by industrial companies Oxalic acid poisoning is usually described in context with ethylene glycol poisoning since oxalic acid or oxalate is a metabolite of ethylene glycol As oxalic acid can be found in certain plants and natural sources oxalic acid toxicity in the form of oxalate nephropathy was also reported from ingestion of star fruit Averrhoa carambola 4 rhubarb5 and ascorbic acid tablets6 Oxalic Acid toxicity can involve inhalation ingestion or direct contact Chronic skin exposure to oxalic acid solution can cause localized pain cyanosis and even gangrenous changes due to localized absorption and resultant arteritis 7 Inhalation of its dust or vapor can cause irritation of the nose throat and lungs causing wheezing coughing and shortness of breath 8 Among the modes of toxicity ingestion is the most life threatening and can lead to multi organ failure such as acute kidney injury A local study by Dignadice reported an 8 18 incidence of acute kidney injury from cases of acute poisoning in the Philippine General Hospital from January 2012 to June 2014 9 Oxalic Acid is poorly absorbed with a bioavailability of 2 to 5 and is excreted unchanged in the urine The oral lethal dose of oxalic acid for adults is 15 to 30 grams although the ingestion of as little as 5g has caused death 10 In acute poisoning soluble oxalates are readily absorbed from the gastrointestinal tract and clinical onset of toxicosis often occurs as early as 1 to 2 hours after ingestion 

Once adsorbed plasma calcium reacts with oxalic acid and other soluble oxalates to form insoluble calcium oxalate and its precipitation in the proximal tubules causes tubular obstruction 11 Studies in oxalate poisoning using ethylene glycol as a model suggested that calcium oxalate monohydrate COM disrupts mitochondrial activity by inducing mitochondrial permeability changes 12 Recent studies in rat models showed that the accumulation of calcium oxalate monohydrate crystals engulfed by the proximal tubular cells produces mitochondrial damage resulting to cell death and tubular necrosis Calcium oxalate crystals may be seen in the urine of poisoned patients up to 40 hours after ingestion of ethylene glycol in the absence of kidney failure and up to 4 days in kidney failure The risk of acute kidney injury increases with the dose ingested 13 14 Acute kidney injury takes 1 to 3 days to develop after ingestion of ethylene glycol 15 A study by Wijerathna et al in Sri Lanka on acute kidney injury following ingestion of potassium permanganate and oxalic acid showed a 3 fold increase in absolute serum creatinine within 16h following ingestion 16 Dignadice found that acute kidney injury related to poisoning is more frequently seen in young adults aged 21 to 30 years old and predominantly males 83 

Urinalysis findings frequently seen in her study include microscopic hematuria and hematuria Metabolic acidosis was also noted in 39 of the acute kidney injury cases Electrolyte imbalances observed were hypokalemia hyponatremia hypocalcemia and hypomagnesemia 9 A study by Mehrotra et al also found the same abnormalities in their study being present in 39 cases out of 53 cases of acute poisoning 17 A case report by Dassanayake and Gnanathasan in Sri Lanka described a case of acute renal failure following oxalic acid poisoning

They presented a 32 year old female who had ingested approximately 12 5g of oxalic acid mixed in a glass of water in attempt at deliberate self harm There was note of leukocytosis with neutrophilic dominance hematuria and metabolic acidosis She developed acute kidney injury and underwent hemodialysis Renal biopsy done on 8th day after ingestion of oxalic acid exhibited acute tubulointerstitial nephritis with diffuse moderate acute tubular damage associated with refractile crystals noted in some proximal tubules Acute kidney injury from oxalate poisoning is usually managed supportively Based on the study by Dassanayake and Gnanathasan only a minority of cases in Sri Lanka have required dialysis 18