A25-08 Not So Mg2+Nificent: A Fatal Case of Severe Hypermagnesemia

Introduction Hypermagnesemia is an electrolyte derangement which has the propensity to become life-threatening. Severe hypermagnesemia can cause stark side effects, including neuromuscular paralysis, respiratory failure and shock. This is a case of magnesium toxicity, presumably secondary to laxative misuse, leading to cardiorespiratory failure and eventually death. Case The patient is a 73-year-old female with a past medical history of hypertension, gastroesophageal reflux disease, and irritable bowel syndrome-consitpation. She had been experiencing significant constipation and abdominal pain for one week, prompting her to contact her primary physician. She was given two enemas, MiraLAX and took over-the-counter magnesium-containing laxatives. While passing a bowel movement, she had a syncopal episode, and emergency services were contacted. She was taken to an outside hospital, where she was noted to be hypotensive, refractory to IV fluids and requiring two pressors. Laboratory tests revealed a lactate level of 13 mmol/L and a magnesium level of 9.5 mg/dL. Unfortunately, her condition worsened, and due to decreased respiratory effort, she was intubated and sedated before being transferred to our facility for a higher level of care.Upon arrival, she was transferred to the ICU and required additional vasopressor support with a third pressor. Repeat laboratory tests showed a lactate level of 11.7 mmol/L, and magnesium was greater than 20 mg/dL. Repeat imaging identified concern for ischemic colitis; however, was not a surgical candidate. Despite aggressive resuscitation efforts including IV antibiotics, stress dose steroids, and calcium infusions, her condition did not improve. Repeat magnesium did not improve, and given her profound hypotension and hypoxia, she was not a candidate for dialysis.Due to hypermagnesemia from laxative overuse and the patient experienced worsening refractory shock and multiorgan failure. Given her prognosis, the family decided to pursue comfort measures, and the patient expired shortly afterward. Discussion Severe hypermagnesemia, albeit rare, has the propensity to precipitate profound cardiovascular and respiratory failure. This occurs due to calcium channel blockade in cardiac tissue and smooth muscle, resulting in decreased contractility and vascular tone, as well as interference with calcium-dependent acetylcholine release at the neuromuscular junction, which reduces respiratory effort. Treatment includes intravenous calcium and fluids, diuretics and dialysis; however, the latter becomes less feasible if hemodynamic instability arises, as in this patient. This case report identifies that clinicians must exercise caution and educate patients about the use of magnesium-containing agents in bowel dysmotility. Furthermore, it demonstrates that hypermagnesemia requires early identification and aggressive treatment. This abstract is funded by: NONE