Is Transcellular Potassium Shifting With Insulin, Albuterol, or Sodium Bicarbonate in Emergency Department Patients With Hyperkalemia Associated With Recurrent Hyperkalemia After Dialysis?

BACKGROUND: Emergency department (ED) treatment of hyperkalemia often involves shifting potassium into the intracellular space. There is uncertainty whether transcellular shifting causes insufficient potassium removal during hemodialysis, resulting in a subsequent need for further medical therapy or multiple sessions of hemodialysis. OBJECTIVE: We sought to determine whether transcellular potassium shifting in ED patients with hyperkalemia who undergo hemodialysis is associated with recurrent hyperkalemia with or without repeat hemodialysis within 24 h. METHODS: This was a retrospective observational study of ED patients with a potassium value > 5.3 mmol/L and ≥1 hemodialysis run. Transcellular shifting medications were defined as albuterol, insulin, and sodium bicarbonate. Primary outcomes were recurrent hyperkalemia with and without repeat hemodialysis within 24 h of the initial dialysis run. Generalized estimating equation models were created for the outcomes using administration of a shifting medication as the primary predictor. RESULTS: Four hundred seventy-nine encounters were identified. In 238 (50%) encounters, a shifting medication was administered. There were 85 outcomes of recurrent hyperkalemia and 36 outcomes of recurrent hyperkalemia with repeat hemodialysis. After adjustment, administration of shifting medications was not associated with recurrent hyperkalemia (adjusted odds ratio 1.26, 95% confidence interval 0.71-2.23) or recurrent hyperkalemia with repeat dialysis (adjusted odds ratio 1.90, 95% confidence interval 0.80-4.48). CONCLUSIONS: Administration of transcellular shifting medications for hyperkalemia in the ED was not associated with either recurrent hyperkalemia after hemodialysis or the need for a second dialysis session within 24 h. Our findings address the uncertainty regarding transcellular potassium shifting before emergent dialysis and support safe ED administration of medications that shift potassium to the intracellular space.

Flush Rate Oxygen for Emergency Airway Preoxygenation.

STUDY OBJECTIVE: Recent data suggest that emergency airway preoxygenation with a bag-valve-mask (BVM) device (held with a tight mask seal but without squeezing the bag) is superior to a nonrebreather (NRB) mask at standard oxygen flow rates. We seek to determine whether preoxygenation with an NRB mask with flush rate oxygen (>40 L/min by fully opening a standard oxygen flowmeter) is noninferior to BVM device with standard-flow oxygen (15 L/min). We also seek to compare the efficacy of preoxygenation with NRB mask at flush rate oxygen with both NRB mask with oxygen at 15 L/min and simple mask at flush rate oxygen. METHODS: We performed a crossover trial using healthy volunteers. In random sequence, subjects underwent 3-minute trials of preoxygenation with nonrebreather mask with oxygen at 15 L/min (NRB-15), nonrebreather mask with flush rate oxygen (NRB-Flush), BVM device with oxygen at 15 L/min (BVM-15), and simple mask with flush rate oxygen. The primary outcome measure was the FeO2 in a single exhaled breath. We compared the FeO2 of NRB-Flush to other study groups, using a prespecified noninferiority margin of 10%. RESULTS: We enrolled 26 subjects. Mean FeO2 values for NRB-15, NRB-Flush, BVM-15, and simple mask with flush rate oxygen were 54% (95% confidence interval [CI] 50% to 57%), 86% (95% CI 84% to 88%), 77% (95% CI 74% to 81%), and 72% (95% CI 69% to 76%), respectively. FeO2 for NRB-Flush was noninferior to BVM-15 (difference 8%; 95% CI 5% to 11%). FeO2 for NRB-Flush was higher than both NRB-15 (FeO2 difference 32%; 95% CI 29% to 35%) and simple mask with flush rate oxygen (FeO2 difference 13%; 95% CI 10% to 17%). CONCLUSION: Preoxygenation with NRB-Flush was noninferior to BVM-15. NRB with flush rate oxygen may be a reasonable preoxygenation method for spontaneously breathing patients undergoing emergency airway management.