White coat hypertension: relevance to clinical and emergency medical services personnel.

Context: White-coat hypertension (WCHT) is a relatively unexplored cause of elevated blood pressure readings in the clinic and in prehospital emergency medical services (EMS) settings.

Objective: The purpose is to summarize WCHT in the clinical office setting and speculate on its relevance in the prehospital setting. This review emphasizes the etiology, diagnosis, prognosis, and application of WCHT in both the clinical and prehospital settings.

Data Sources: A systematic literature review was undertaken with the Medline PubMed database, UpToDate, and Web of Science. The following search queries were used: "prehospital WCHT, " " prehospital white coat hypertension, " "EMS WCHT, " " emergency medical services white coat hypertension, " " ambulatory WCHT, " " ambulatory white coat hypertension, " " labile HTN, " " labile hypertension, " " variable HTN, " and " variable hypertension " limited to 1980-July 2006. Only human studies published in English were included.

Study Selection: The reviews yielded 233 articles initially, which were narrowed down to those mentioned herein by direct relevance to either the observed WCHT effect in the clinic or the prehospital setting.

Data Synthesis: WCHT has not been applied or explored in the prehospital setting as of yet, and thus all data were shown to be related to clinical WCHT. It was found that WCHT may not be simply a benign entity but rather part of a continuum in the development of true essential hypertension. It was found that WCHT patients, when followed, had higher morbidity than non-WCHT patients but less morbidity than established essential hypertensive patients.

Conclusions: WCHT may be a significant step toward the evolution into full-blown hypertension. For many populations, routine access to a healthcare provider is not possible, and thus their only interaction with healthcare providers may be in the prehospital EMS setting. On the basis of findings of true organic morbidity in WCHT, it comes to reason that contact with patients in the setting should be thorough--including urging follow-up for those whose blood pressure is found to be elevated in the presence of healthcare professionals.