Techniques of Vital SignsTechniques of Vital Signs

John Gazewood, MD, MSPHJohn Gazewood, MD, MSPH

Department of Family MedicineDepartment of Family Medicine

ObjectivesObjectives

Define “normal” in several ways.Define “normal” in several ways.

Describe correct technique of measuring Describe correct technique of measuring vital signs. vital signs.

Describe correct technique for evaluating Describe correct technique for evaluating pulses.pulses.

Know that different populations may have Know that different populations may have different normal values.different normal values.

What Does “Normal” Mean?What Does “Normal” Mean?

AverageAverage•• Population (sample) meanPopulation (sample) mean

“Healthy” “Healthy” -- appropriate physiologic appropriate physiologic functionfunction

These two definitions can be incompatibleThese two definitions can be incompatible

What Does “Normal” Mean?What Does “Normal” Mean?

Average Blood Pressure, by AgeAverage Blood Pressure, by AgeAverage Blood Pressure, by Age

60708090

100110120130140150160170

36 41 46 51 56 61 66 71 76

SPBDBP

AgeAge

Bloo

d Pr

essu

re,

mm

Hg

Bloo

d Pr

essu

re,

mm

Hg

Kannel, Bull NY Acad Kannel, Bull NY Acad Med, 54(6), 1978Med, 54(6), 1978

Risk of CV Disease Increases With SBPRisk of CV Disease Increases Risk of CV Disease Increases With SBPWith SBP

0102030405060708090

74-119 120-139 140-159 160-179 >180Systolic Blood Pressure, mm Hg

Age

adus

ted

annu

al ra

te p

er

1000

Age: 65-94Age: 35-64

Framingham study

TemperatureTemperature

OralOral

RectalRectal•• Often used in infants, continuous monitoring for Often used in infants, continuous monitoring for

severe hypothermia/hyperthermiasevere hypothermia/hyperthermia

AxillaryAxillary•• Poor correlation with rectal temperaturePoor correlation with rectal temperature

•• Don’t use if accurate temperature importantDon’t use if accurate temperature important–– neonates may be exceptionneonates may be exception

BMJ 320(29), April 2000BMJ 320(29), April 2000

Tympanic TemperatureTympanic Temperature

Measures core Measures core temperature temperature

Caution pointCaution point•• Point at TMPoint at TM

•• No waxNo wax

Temperature Temperature -- Normal ValuesNormal Values

Oral Oral -- 373700C C (98.6(98.60 0 F)F), Fever > 38 °C , Fever > 38 °C (100.4°F)(100.4°F)((wunderlichwunderlich))

Oral Oral -- 36.836.800C C (98.2(98.20 0 F)F), Fever > 37.3 °C , Fever > 37.3 °C (99.9(99.900F)F) (JAMA, 269:1578(JAMA, 269:1578--80)80)

Rectal 0.4Rectal 0.400C to 0.5C to 0.500C C (0.7(0.700F to 0.8F to 0.800F)F) higher higher than oralthan oral

Tympanic 0.8Tympanic 0.800C C (1.4(1.400F)F) higher than oralhigher than oral

Respiratory RateRespiratory Rate

Respiratory cycles per minuteRespiratory cycles per minute

Observe rise and fall of chestObserve rise and fall of chest

Depth, effort of breathing, rhythmDepth, effort of breathing, rhythm•• Accessory muscle use, retractions, nasal Accessory muscle use, retractions, nasal

flaringflaring

For infantsFor infants•• observe abdomen observe abdomen

•• count for 60 seconds, or two thirty second count for 60 seconds, or two thirty second intervalsintervals

PulsePulse

Number of cardiac cycles per minuteNumber of cardiac cycles per minute

Pulse affected by:Pulse affected by:•• Volume of blood ejected (stroke volume)Volume of blood ejected (stroke volume)

•• Distensibility of aorta and large arteriesDistensibility of aorta and large arteries

•• Viscosity of bloodViscosity of blood

•• Rate of cardiac emptyingRate of cardiac emptying

•• Peripheral arteriolar resistancePeripheral arteriolar resistance

Palpation of PulsesPalpation of Pulses

Pads of second and third fingersPads of second and third fingers•• Gentle pressureGentle pressure

Assess:Assess:•• Rate (15 or 30 seconds, multiply by 4 or 2Rate (15 or 30 seconds, multiply by 4 or 2

•• Rhythm (regular, irregular, irregularly Rhythm (regular, irregular, irregularly irregular)irregular)

•• AmplitudeAmplitude

•• Contour (upstroke, peak, descending)Contour (upstroke, peak, descending)

Radial Pulse

Brachial Pulse

Carotid PulseCarotid Pulse

Femoral PulseFemoral Pulse

Popliteal Pulse

Dorsalis Pedis (DP) PulseDorsalis Pedis (DP) Pulse

Posterior Tibialis (PT) PulsePosterior Tibialis (PT) Pulse

Describing PulsesDescribing Pulses

Rate and rhythmRate and rhythm

AmplitudeAmplitude•• 0 0 -- absentabsent

•• 1+ 1+ -- decreaseddecreased

•• 2+ 2+ -- normalnormal

•• 3+ 3+ -- increasedincreased

•• 4+ 4+ -- boundingbounding

ContourContour

Abnormal PulsesAbnormal Pulses

Measurement of Blood PressureMeasurement of Blood Pressure

Choose correct size cuffChoose correct size cuff

Place cuff on limb (usually arm)Place cuff on limb (usually arm)

Measure palpable systolic blood pressureMeasure palpable systolic blood pressure

Measure blood pressureMeasure blood pressure

Record the blood pressureRecord the blood pressure

Choose an Appropriately Sized Choose an Appropriately Sized Blood Pressure CuffBlood Pressure Cuff

Bladder width ˜ 40% of limb circumference, Bladder width ˜ 40% of limb circumference, length ˜ 80% of limb circumference. length ˜ 80% of limb circumference.

Too large cuff underestimates blood Too large cuff underestimates blood pressure.pressure.

Too small cuff overestimates blood Too small cuff overestimates blood pressure.pressure.

Place the Blood Pressure Cuff on Place the Blood Pressure Cuff on the Limbthe Limb

Don’t use arm with arteriovenous fistula or Don’t use arm with arteriovenous fistula or on side of radical mastectomyon side of radical mastectomyNo clothing on upper arm, or very light No clothing on upper arm, or very light sleeve.sleeve.On arm, lower edge of cuff 2 to 3 cm above On arm, lower edge of cuff 2 to 3 cm above antecubital fossaantecubital fossaPlace cuff snugly about the limb. Place cuff snugly about the limb. Center bladder over brachial arteryCenter bladder over brachial artery

Measure the Palpable Systolic Measure the Palpable Systolic Blood PressureBlood Pressure

Support patient’s arm, at heart level.Support patient’s arm, at heart level.

Palpate radial artery, rapidly pump up cuff Palpate radial artery, rapidly pump up cuff until pulse no longer palpable.until pulse no longer palpable.

Pump up cuff another 20 mm hg.Pump up cuff another 20 mm hg.

Release pressure at 2 to 3 mm hg per Release pressure at 2 to 3 mm hg per second, until pulse is felt. second, until pulse is felt.

Rapidly release pressure from cuff.Rapidly release pressure from cuff.•• Wait 30 secondsWait 30 seconds

Measure the Blood PressureMeasure the Blood Pressure

Bell of stethoscope over arteryBell of stethoscope over arteryRapidly pump up cuff to 20 Rapidly pump up cuff to 20 -- 30 mm hg over 30 mm hg over palpable systolic blood pressure.palpable systolic blood pressure.Release pressure in cuff at 2 to 3 mm hg Release pressure in cuff at 2 to 3 mm hg per second, listen forper second, listen for korotkoffkorotkoff sounds.sounds.Record BP as systolic/diastolic (120/80)Record BP as systolic/diastolic (120/80)Repeat in other arm. Take higher reading as Repeat in other arm. Take higher reading as patient’s blood pressure.patient’s blood pressure.

Korotkoff Phases of BPKorotkoff Phases of BP

Important Considerations in BP Important Considerations in BP MeasurementMeasurement

Sphygmomanometer dial/column should Sphygmomanometer dial/column should be at eye level.be at eye level.

Patient seated, back supported and feet on Patient seated, back supported and feet on the floorthe floor

Patient at rest for 5 minutes Patient at rest for 5 minutes

Pt. Refrain from caffeine or nicotine Pt. Refrain from caffeine or nicotine •• JAMA, 273; pp 1211JAMA, 273; pp 1211--1218, 19951218, 1995

Pitfalls in blood pressure Pitfalls in blood pressure measurementmeasurement

ArrhythmiasArrhythmias

Venous congestionVenous congestion

Korotkoff sounds do not disappearKorotkoff sounds do not disappear

Does This Patient Have Does This Patient Have Hypertension?Hypertension?

Diagnosis should be based on average of Diagnosis should be based on average of two or three readingstwo or three readings•• Individual variation in blood pressureIndividual variation in blood pressure

•• Regression to the meanRegression to the mean

•• Especially in patients near diagnostic cut pointEspecially in patients near diagnostic cut point

JNC VI BP ClassificationJNC VI BP Classification

Category Systolic Diastolic Follow-upOptimal <120 and <80 2 yearsNormal <130 and <85 2 yearsHighNormal

130-139 or 85-89 1 year

Stage 1 140-159 or 90-99 2 monthsStage 2 160-179 or 100-109 1 monthStage 3 ≥180 or ≥110 1 wk

Does the patient have Does the patient have hypovolemia?hypovolemia?

Measure pulse and blood pressure in Measure pulse and blood pressure in supine and standing positionsupine and standing position•• Supine Supine -- wait 1 minutewait 1 minute

•• Standing Standing -- wait 2 minuteswait 2 minutes

Pulse increase Pulse increase ≥≥ 30 bpm30 bpm

Unable to stand for VS measurementUnable to stand for VS measurementJAMA, 281 (11); 1022JAMA, 281 (11); 1022--10291029