ObjectiveTo review, systematically, the physical diagnosis of
hypovolemia in adults.MethodsWe 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.ResultsWhen 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.ConclusionsA 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.

https://jamanetwork.com/journals/JAMA/articlepdf/189113/jrc80003.pdf

Is This Patient Hypovolemic

Background and Purpose—The association between orthostatic hypotension (OH) and stroke has rarely been investigated in longitudinal studies. The purpose of the present study was to determine whether OH predicts ischemic stroke in a middle-aged, biethnic population after adjustment for known stroke risk factors. Diastolic, systolic, and consensus OH were evaluated for baseline associations and for the ability to predict stroke. Methods—In 11 707 persons from the Atherosclerosis Risk in Communities (ARIC) cohort who were free of stroke and overt heart disease at baseline, Cox proportional hazards analyses modeled the association between OH at baseline and incident ischemic stroke over 7.9 years of follow-up. OH was defined as a systolic blood pressure drop ≥20 mm Hg (systolic OH), a diastolic blood pressure drop ≥10 mm Hg (diastolic OH), or a drop in either (consensus OH) when a person changed from a supine to standing position. Results—OH was predictive of ischemic stroke, even after adjustment for numerou...

Orthostatic hypotension as a risk factor for stroke: the atherosclerosis risk in communities (ARIC) study, 1987-1996.

Aims Orthostatic hypotension (OH) has been linked to increased mortality and incidence of cardiovascular disease in various risk groups, but determinants and consequences of OH in the general population are poorly studied.

Methods and results Prospective data of the Swedish ‘Malmo Preventive Project’ ( n = 33 346, 67.3% men, mean age 45.7 ± 7.4 years, mean follow-up 22.7 ± 6.0 years) were analysed. Orthostatic hypotension was found in 6.2% of study participants and was associated with age, female gender, hypertension, antihypertensive treatment, increased heart rate, diabetes, low BMI, and current smoking. In Cox regression analysis, individuals with OH had significantly increased all-cause mortality (in particular those aged less than 42 years) and coronary event (CE) risk. Mortality and CE risk were distinctly higher in those with systolic blood pressure (BP) fall ≥30 mmHg [hazard ratio (HR): 1.6, 95% CI 1.3–1.9, P < 0.0001 and 1.6, 95% CI 1.2–2.1, P = 0.001] and diastolic BP fall ≥15 mmHg (HR: 1.4, 95% CI 1.1–1.9, P = 0.024 and 1.7, 95% CI 1.1–2.5, P = 0.01). In addition, impaired diastolic BP response had relatively greater impact (per mmHg) on CE incidence than systolic reaction.

Conclusion Orthostatic hypotension can be detected in ∼6% of middle-aged individuals and is often associated with such comorbidities as hypertension or diabetes. Presence of OH increases mortality and CE risk, independently of traditional risk factors. Although both impaired systolic and diastolic responses predict adverse events, the diastolic impairment shows stronger association with coronary disease.

Orthostatic hypotension predicts all-cause mortality and coronary events in middle-aged individuals (The Malmo Preventive Project).

Background— An association between orthostatic hypotension (OH) and mortality has been reported, but studies are limited to older adults or high-risk populations. Methods and Results— We investigated the association between OH (a decrease of 20 mm Hg in systolic blood pressure or a decrease of 10 mm Hg in diastolic blood pressure on standing) and 13-year mortality among middle-aged black and white men and women from the Atherosclerosis Risk in Communities Study (1987–1989). At baseline, 674 participants (5%) had OH. All-cause mortality was higher among those with (13.7%) than without (4.2%) OH. After we controlled for ethnicity, gender, and age, the hazard ratio (HR) for OH for all-cause mortality was 2.4 (95% confidence interval [CI], 2.1 to 2.8). Adjustment for risk factors for cardiovascular disease and mortality and selected health conditions at baseline attenuated but did not completely explain this association (HR=1.7; 95% CI, 1.4 to 2.0). This association persisted among subsets that (1) excluded t...

Orthostatic Hypotension Predicts Mortality in Middle-Aged Adults The Atherosclerosis Risk in Communities (ARIC) Study

Normative data are limited on autonomic function tests, especially beyond age 60 years. We therefore evaluated these tests in a total of 557 normal subjects evenly distributed by age and gender from 10 to 83 years. Heart rate (HR) response to deep breathing fell with increasing age. Valsalva ratio varied with both age and gender. QSART (quantitative sudomotor axon-reflex test) volume was consistently greater in men (approximately double) and progressively declined with age for all three lower extremity sites but not the forearm site. Orthostatic blood pressure reduction was greater with increasing age. HR at rest was significantly higher in women, and the increment with head-up tilt fell with increasing age. For no tests did we find a regression to zero, and some tests seem to level off with increasing age, indicating that diagnosis of autonomic failure was possible to over 80 years of age.

Effect of age and gender on sudomotor and cardiovagal function and blood pressure response to tilt in normal subjects.

The authors' objective was to review previous studies of immediate (first 30 seconds) and stabilized (30 seconds to 20 minutes) hemodynamic responses of healthy adults to the head-up posture, with particular reference to alteration of such responses in the elderly and the usefulness of such data in the diagnosis of orthostatic hypotension. The immediate response in healthy young adults is characterized by a prompt rise in heart rate, which peaks at about 8 to 15 seconds and then tapers; the arterial pressure and total vascular resistance decrease sharply at 5 to 10 seconds, followed by a rapid rebound and overshoot. Over the first 30 seconds there is a steady parallel decline of thoracic blood volume and stroke volume; there is also an initial surge of cardiac output followed by a steady decrease. During the stabilized response (30 seconds to 20 minutes), the hemodynamic variables are relatively steady, showing average increases in heart rate of about 15 to 30%, in diastolic pressure of 10 to 15%, and in total vascular resistance of 30 to 40%; during the 5th to 20th minutes there are also decreases in thoracic blood volume averaging about 25 to 30%, in cardiac output 15 to 30%, and in pulse pressure about 5 to 10%. It is evident that in normal human subjects, assumption of the upright posture results in profound hemodynamic changes, most of them occurring during the first 30 seconds. In elderly subjects (aged 60-69 years), there are, in the upright posture, lesser increments of heart rate and diastolic pressure, but no significant differences from younger age groups in the response of thoracic blood volume, cardiac output or total vascular resistance. However, beginning at about age 75, there is an increasing incidence of orthostatic hypotension, which averages about 14 to 20% at age 75 and older. The tendency toward orthostatic hypotension in the elderly is due (1) to the structural and functional changes in the circulation itself, (2) to a decline in autonomic function, and (3) to a probable functional deficiency of the skeletal muscle pump. The authors believe that closer hemodynamic monitoring of orthostatic hypotension patients would considerably increase our understanding and aid in the diagnosis of this condition.

Molly Erickson

Papers

Hemodynamic response to the upright posture.