* hypotension (sap \< 100 mmhg or dap \< 50 mmhg or map \< 65 mmhg) * hyperkalemia (\> 5.5 mmol/l) * acute kidney injury (urine output \< 0.5 ml/kg/hr and new creatinine \> 200 mmol/l, or increase \> 100 mmol/l, or gfr \< 30 ml/min) * use of aliskiren in patients with diabetes mellitus (type 1 or type 2) or moderate-severe renal impairment (gfr less than 60ml/min) * use of arb/acei within 7 days of presentation * pregnant or breastfeeding * have a known allergy to arbs or any component of the drug product * have written legal document to withhold life-sustaining (patients not wishing to receive cardiopulmonary resuscitation (cpr) can participate if other medical treatments will be given) * have signed a do no resuscitate (dnr) form

* hypotension (sap \< 100 mmhg or dap \< 50 mmhg or map \< 65 mmhg) * hyperkalemia (\> 5.5 mmol/l) * acute kidney injury (urine output \< 0.5 ml/kg/hr and new creatinine \> 200 mmol/l, or increase \> 100 mmol/l, or gfr \< 30 ml/min) * use of aliskiren in patients with diabetes mellitus (type 1 or type 2) or moderate-severe renal impairment (gfr less than 60ml/min) * use of arb/acei within 7 days of presentation * pregnant or breastfeeding * have a known allergy to arbs or any component of the drug product * have written legal document to withhold life-sustaining (patients not wishing to receive cardiopulmonary resuscitation (cpr) can participate if other medical treatments will be given) * have signed a do no resuscitate (dnr) form

hypotension (sap < 100 mmhg or dap < 50 mmhg or map < 65 mmhg) hyperkalemia (> 5.5 mmol/l) acute kidney injury (urine output < 0.5 ml/kg/hr and new creatinine > 200 mmol/l, or increase > 100 mmol/l, or gfr < 30 ml/min) use of aliskiren in patients with diabetes mellitus (type 1 or type 2) or moderate-severe renal impairment (gfr less than 60ml/min) use of arb/acei within 7 days of presentation pregnant or breastfeeding have a known allergy to arbs or any component of the drug product have written legal document to withhold life-sustaining (patients not wishing to receive cardiopulmonary resuscitation (cpr) can participate if other medical treatments will be given) have signed a do no resuscitate (dnr) form

hypotension (sap < 100 mmhg or dap < 50 mmhg or map < 65 mmhg) hyperkalemia (> 5.5 mmol/l) acute kidney injury (urine output < 0.5 ml/kg/hr and new creatinine > 200 mmol/l, or increase > 100 mmol/l, or gfr < 30 ml/min) use of aliskiren in patients with diabetes mellitus (type 1 or type 2) or moderate-severe renal impairment (gfr less than 60ml/min) use of arb/acei within 7 days of presentation pregnant or breastfeeding have a known allergy to arbs or any component of the drug product have written legal document to withhold life-sustaining (patients not wishing to receive cardiopulmonary resuscitation (cpr) can participate if other medical treatments will be given) have signed a do no resuscitate (dnr) form

- hypotension (sap < 100 mmhg or dap < 50 mmhg or map < 65 mmhg) - hyperkalemia (> 5.5 mmol/l) - acute kidney injury (urine output < 0.5 ml/kg/hr and new creatinine > 200 mmol/l, or increase > 100 mmol/l, or gfr < 30 ml/min) - use of arb/acei within 7 days of presentation - pregnant or breastfeeding - have a known allergy to losartan or any component of the drug product - have written legal document to withhold life-sustaining (patients not wishing to receive cardiopulmonary resuscitation (cpr) can participate if other medical treatments will be given) - have signed a do no resuscitate (dnr) form

- hypotension (sap < 100 mmhg or dap < 50 mmhg or map < 65 mmhg) - hyperkalemia (> 5.5 mmol/l) - acute kidney injury (urine output < 0.5 ml/kg/hr and new creatinine > 200 mmol/l, or increase > 100 mmol/l, or gfr < 30 ml/min) - use of arb/acei within 7 days of presentation - pregnant or breastfeeding - have a known allergy to losartan or any component of the drug product - have written legal document to withhold life-sustaining (patients not wishing to receive cardiopulmonary resuscitation (cpr) can participate if other medical treatments will be given) - have signed a do no resuscitate (dnr) form