title: High altitude-related hypertensive crisis and acute kidney injury in an asymptomatic healthy individual.
abstract: BACKGROUND
  High-altitude exposure causes a mild to moderate rise in systolic and diastolic blood pressure. This case report describes the first documented case of a hypertensive crisis at altitude, as well as the first report of the occurrence of acute kidney injury in the context of altitude-related hypertension.
  
  
  METHODS
  A healthy, previously normotensive 30-year old, embarked on a trek to Everest Base Camp (5300 m). During his 11-day ascent the subject developed increasingly worsening hypertension. In the absence of symptoms, the individual initially elected to remain at altitude as had previously been the plan. However, an increase in the severity of his hypertension to a peak of 223/119 mmHg resulted in a decision to descend. On descent he was found to have an acute kidney injury that subsequently resolved spontaneously. His blood pressure reverted to normal at sea level and subsequent investigations including a transthoracic echocardiogram, cardiac magnetic resonance imaging, renal ultrasound, and urinary catecholamines were normal.
  
  
  CONCLUSIONS
  This report challenges the view that transient rises in blood pressure at altitude are without immediate risk. We review the evidence that altitude induces hypertension and discuss the implications for the management of hypertension at altitude.
authors.affiliation: Centre for Altitude Space and Extreme Environment Medicine, University College London, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London, W1T 7HA UK.
authors.forename: Edward
authors.initials: E
authors.lastname: Gilbert-Kawai
authors.affiliation: Centre for Altitude Space and Extreme Environment Medicine, University College London, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London, W1T 7HA UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Martin
authors.affiliation: Centre for Altitude Space and Extreme Environment Medicine, University College London, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London, W1T 7HA UK ; Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, University of Southampton, Southampton, SO16 6YD UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Grocott
authors.affiliation: Centre for Altitude Space and Extreme Environment Medicine, University College London, UCLH NIHR Biomedical Research Centre, Institute of Sport and Exercise Health, 170 Tottenham Court Road, London, W1T 7HA UK ; Integrative Physiology and Critical Illness Group, Clinical and Experimental Sciences, University of Southampton, Southampton, SO16 6YD UK.
authors.forename: Denny
authors.initials: D
authors.lastname: Levett
keywords: Acute kidney injury; High altitude; Hypertension