The current guideline of asymptomatic severe hypertension (ASH) treatment in emergency department (ED) recommends through low level of evidence that the patients should not be rapidly decreased their BP in ED but instead receive oral antihypertensive treatment and close outpatient follow-up is needed. Unfortunately, there was some ambiguity in the time point of BP measurement in ED described in the past literature because high BP on ED admission may significantly decrease within hours without any medications. The importance of pre-ED discharge BP, which can still be critically high, that may affect the follow-up outcome has never been investigated. The study aim of this study is to evaluate the physicians' treatment strategies as well as immediate clinical outcomes between patients with severely- and moderately-elevated pre-discharge BP after management of ASH its in ED during the recent recommendation. The secondary outcome is to compare the BP at follow-up in these two groups.

The investigators will follow the patients with asymptomatic severe hypertension who attend ED of King Chulalongkorn Memorial Hospital (KCMH), an urban, 1,500-bed, university-affiliated, tertiary care hospital as well as treatment strategies. A management strategy whether to start the drugs in ED with or without a period of observation or immediately after discharge without any observation depends on the treating physicians' judgment. The investigators predefined the pre-discharge BP at ED into two groups; high BP (pre-discharge SBP < 180 mmHg) and severely high BP (pre-discharge SBP >= 180mmHg) groups. Every eligible patient was scheduled for the internal medicine clinic for continuous care of the high blood pressure within 3-7 days after discharge. Medical records were retrieved for the follow-up BP, compliance and associated adverse events at the clinic. The investigators will make telephone follow-ups to the participants or their contact personnel in every case at 10 days after ED presentation to identify the deceased cases or those with major morbidity as well as the compliance to their medications.

Inclusion Criteria:

• Adult patients ≥18 years old
• Systolic BP (SBP) greater or equal to 180 mmHg
• Diastolic BP (DBP) ≥ 100 mmHg

Exclusion Criteria:

• Acute end-organ damage related to severe hypertension that required rapid intravenous antihypertensive drugs for acute treatment involving cardiovascular (acute chest pain, heart failure, acute coronary syndromes, acute aortic syndromes), renal (acute kidney injury), ocular (retinal hemorrhage or hypertensive retinopathy) and central nervous system (seizure, acute cerebrovascular diseases, hypertensive encephalopathy)
• Hypertension caused by medical toxicology (e.g. use of sympathomimetic drugs (amphetamine and its derivatives), alcohol withdrawal syndrome
• Significantly decreased renal function (serum creatinine ≥ 1.5 mg/dL or creatinine clearance ≤ 30 ml/min)
• Pregnant women
• Moderate to severe pain (pain score on visual analog scale ≥ 5 centimeters out of 10)
• BP decrease to less than 180 mmHg after 10-minute bed rest without any medical treatment
• Having concurrent medical conditions that needed hospitalization.

Adult patients (≥18 years old) who presented in our ED with systolic BP (SBP) greater or equal to 180 mmHg and diastolic BP (DBP) ≥ 100 mmHg were consecutively enrolled in this study.

7 days

The results may not be generalizable to other centers with different treatment practices. We still had a considerable percentage of patients who were lost-to-follow-up that may have affected the results. The size of population was relatively small.