HEART AND BLOOD VESSEL DISORDERS - Medicine for Mountaineering and Other Wilderness Activities - page 218

radial pulse first appears. This pressure is 10 to 20 mm lower than the pressure determined
by a stethoscope, but the method is reliable in an emergency.
If a blood pressure cuff is not available and the individual is alert, the brain is well
perfused and an adequate blood pressure is probably present. The systolic blood pressure,
which is most significant, can be roughly estimated by the presence of palpable pulses in
various locations. If a pulse is palpable at the wrist (radial pulse), the systolic pressure is
at least 80 mm Hg. If no radial pulse can be felt but a pulse can be palpated in the groin
(femoralpulse),thesystolicpressureisapproximately70mmHg.Ifthefemoralpulsecan-
not be detected but a carotid artery pulse can be felt, the systolic pressure is approximately
60 mm Hg.
Peripheral Circulation
The lips, tongue, and fingernails (nail beds) are normally pink, but when oxygen con-
centration in blood is low, they become blue or purple. This discoloration (cyanosis) is
common at high altitude and is usually severe in high-altitude pulmonary edema. At lower
elevations cyanosis usually indicates inadequate oxygenation ofthe bloodbythe lungsand
is caused by disorders such as airway obstruction, pneumonia, or chest injuries.
Whenbloodpressureislowandbloodflowtotheextremitiesisdecreased,thenailbeds
andlipsmaybecyanoticeventhoughoxygenationofthebloodinthelungsisnormal.This
type of cyanosis is due to decreased blood flow and is commonly seen in shock. The skin
may appear mottled.
Anemia or blood loss may give the nails a pale color.
Edema is an accumulation of excess water in the tissues and is not uncommon during
the first few days at high altitude, particularly in women. It is caused by retention of salt
and water. The face may be puffy in the morning, and the feet or ankles may be mildly
swollen. More severe edema, particularly if progressive and lasting for more than a week,
suggests heart failure or kidney disease and should be investigated.
Individuals who have persistent shortness of breath with mild exertion, or who experi-
enceshortnessofbreathwhenlyingflatthatisrelieved bysittingup,usuallyhavefluidac-
cumulationsinthelungs(pulmonaryedema).Inyoungindividualsathighelevations,high-
altitude pulmonary edema should be suspected. In older individuals at lower elevations,
heart failure is a common cause. When listening to the chest of someone with pulmonary
edemafromanycause,cracklesorbubblingsoundscanbeheardwitheachbreath.(Asthma
usually produces wheezes or squeaking or groaning sounds, particularly during expiration.
Auscultation of the lungs is discussed further in Chapter 18: Respiratory Disorders . )
Writtenrecordsarevitalinthecareofanyonesuspectedofhavingheartdisease.Allob-
servations, including the time of the observations, must be recorded. Examinations should
be repeated at frequent, regular intervals, such as every two to four hours. Physicians need