HYPONATREMIA - SWIMMING

Abstract

HISTORY: A 33-year old sports medicine physician developed sudden onset of nausea, vomitting, shortness of breath, and near syncope on the fifth and final day of the national swimming championships for which he was the covering physician. He had been previously feeling well with a good appetite and had swum daily between sessions. The daily high temperature ranged from 105–110 degrees at this outdoor national championships. The patient had been drinking plenty of fluids and staying out of the sun. He had no prior history of asthma or heart disease and no recent illness. When he felt pre-syncopal, he reported to the other covering physician at the medical tent. The patient was described as pale and diaphoretic. He vomitted copious amounts of clear liquid. Initial pulse and blood pressure supine and standing were normal. The patient was instructed to drink two bottles of water which he vomitted immediately. The patient then felt some better and drank a sports drink which he kept down. Urine output was normal and described as clear. He felt well enough to go back to his hotel, but the symptoms returned within two hours. The patient then drove himself to the emergency room. PHYSICAL EXAM: Examination at the event revealed a pale, diaphoretic otherwise healthy appearing male who was in mild distress and somewhat confused. Pulse was variable between 70–90. Blood Pressure was 132/80 standing and 124/78 supine. Mucous membranes were slightly dry and eyes were sunken. Cardiovascular exam revealed a normal rhythm with a variable rate. Pulses were strong and symmetrical in all extremities. There was no lower extremity edema or cyanosis or skin tenting. The lung were clear and the respiratory rate was 16–20 and unlabored. Abdominal exam was unremarkable and screening neuro exam was normal. At the ER, the patient was more anxious but not confused. The blood pressure was 156/100 with a pulse of 100. The exam was otherwise unchanged. DIFFERNTIAL DIAGNOSIS: Myocardial Infarction Pulmonary Embolus Dehydration Hyponatremia ER TESTS: EKG, CXR, Troponin, CK-MB, D-Dimer all negative. Na 125 K 3.4 Cl 92 Glc 121 BUN 10 Creat 1.0 Osm 254 Hgb 13.1 Hct 36.8 WBC 7.4 UA Sp Gr 1.001 Urine Osm not done WORKING DIAGNOSIS AND PLAN: Dehydration/Hyponatremia One liter of LR given in ER and patient released with instructions to push sports drink and rest. Patient decides to fluid restrict and eat potato chips for two days then recheck labs. FOLLOW-UP: The patient felt better and continued to produce copious amounts of dilute urine for 48 hours while fluid resticting and increasing sodium intake. REPEAT LABS(at 72 hours): Na 139 K 4.2 Cl 100 Glc 69 BUN 14 Creat 0.3 Osm 276 Hgb 13.9 Hct 39.8 WBC 6.8 UA Sp Gr 1.005 Urine Osm 195 FINAL DIAGNOSIS: Dilutional Hyponatremia secondary to salt losses and overhydration.