Objective To review, systematically, the physical diagnosis of
hypovolemia in adults.
Methods We searched MEDLINE (January 1966-November 1997), personal
files, and bibliographies of textbooks on physical diagnosis and
identified 10 studies investigating postural vital signs or the
capillary refill time of healthy volunteers, some of whom underwent
phlebotomy of up to 1150 mL of blood, and 4 studies of patients
presenting to emergency departments with suspected hypovolemia, usually
due to vomiting, diarrhea, or decreased oral intake.
Results When clinicians evaluate adults with suspected blood loss,
the most helpful physical findings are either severe postural dizziness
(preventing measurement of upright vital signs) or a postural pulse
increment of 30 beats/min or more. The presence of either finding has a
sensitivity for moderate blood loss of only 22% (95% confidence
interval [CI], 6%-48%) but a much greater sensitivity for large
blood loss of 97% (95% CI, 91%-100%); the corresponding specificity
is 98% (95% CI, 97%-99%). Supine hypotension and tachycardia are
frequently absent, even after up to 1150 mL of blood loss (sensitivity,
33%; 95% CI, 21%-47%, for supine hypotension). The finding of mild
postural dizziness has no proven value. In patients with vomiting,
diarrhea, or decreased oral intake, the presence of a dry axilla
supports the diagnosis of hypovolemia (positive likelihood ratio, 2.8;
95% CI, 1.4-5.4), and moist mucous membranes and a tongue without
furrows argue against it (negative likelihood ratio, 0.3; 95% CI,
0.1-0.6 for both findings). In adults, the capillary refill time and
poor skin turgor have no proven diagnostic value.
Conclusions A large postural pulse change (≥30 beats/min) or
severe postural dizziness is required to clinically diagnose
hypovolemia due to blood loss, although these findings are often absent
after moderate amounts of blood loss. In patients with vomiting,
diarrhea, or decreased oral intake, few findings have proven utility,
and clinicians should measure serum electrolytes, serum blood urea
nitrogen, and creatinine levels when diagnostic certainty is
required.