Reduction of Risk PotentialLesson 7.1
Vital Signs: Changes, Trends, and Abnormalities
Measure it right, know what abnormal means, and catch the trend before the client crashes.
By the end you can
- Measure each vital sign with the technique that makes the number true
- Link an abnormal vital sign to its cause, including shock and Cushing's triad
- Spot a deteriorating trend early and escalate with SBAR
Your case
Med-surg · 6 hours after a bowel resection
Ms. K, 58. Her 1400 BP still reads normal. It was taken with a standard adult cuff on her large upper arm.
She was chatting at 1000. Now she is restless and keeps asking for water.
HR 84 to 108BP 134/80 to 118/72RR 16 to 22SpO2 95%
Hold that thought
- Can you trust the 118/72?
- Which vital sign changed first, and what does the trend suggest?
- Do you need a provider order to call for help?
You will answer all three at the end of the lesson.
Concept 1 · Normal ranges
Know the numbers, then compare to her baseline
- Temperature
- 97.8 to 99.1 F (36.5 to 37.3 C)
- Pulse
- 60 to 100 per minute
- Respirations
- 12 to 20 per minute
- Blood pressure
- Under 120 systolic and under 80 diastolic
- SpO2
- 95 to 100%
- Pain
- Whatever the client says it is. Reassess after every intervention
Match the temperature route to its note
Concept 2 · Pulse, respirations, SpO2
Count it right or the number means nothing
Pulse
- Radial for routine checks
- Apical (5th intercostal space, left midclavicular line): irregular rhythm, before digoxin, infants
- Irregular? Count a full 60 seconds
- Document rate, rhythm, and quality: bounding, thready, weak
Respirations
- Don't tell the client you are counting: they will change the pattern
- Assess rate, depth, rhythm, effort
- Look for accessory muscles, nasal flaring, retractions
- Irregular? Count a full 60 seconds
Pulse oximetry
- Under 90%: hypoxemia. Intervene now
- Falsely high in carbon monoxide poisoning
- Unreliable with nail polish (remove it), cold fingers (warm them), poor perfusion, motion
Pick the pain scale
- Adult who can rate it:
- Child:
- Infant or nonverbal client:
- Client with dementia:
Concept 3 · Blood pressure technique
The cuff decides the number
Set it up right
- Cuff width: 40% of the arm circumference. The bladder encircles at least 80%
- Seated 5 minutes: back supported, feet flat, arm supported at heart level
- On bare skin, never over clothing. No talking
Falsely high or falsely low?
Tap an error, then tap the box it belongs in.
Quick check 1 of 4
A client with a large upper arm reads 156/94 with a standard adult cuff. What does the nurse do first?
A cuff too small for the arm reads falsely high. Correct the technique before you document or report, or the client may be treated for a number that isn't real. Switching arms with the same cuff repeats the error.
Concept 4 · Both arms and orthostatics
Both arms first, then stand them up
First visit
- Measure both arms
- Over 20 mmHg apart: think coarctation or subclavian stenosis. Notify the provider
- Use the higher arm from then on
Orthostatic vitals
- Supine, sitting, standing. Wait 1 to 3 minutes between
- Positive: systolic drops 20 or more, or diastolic drops 10 or more
- HR often climbs 20 or more to compensate
- Causes: dehydration, bleeding, bed rest, antihypertensives, diuretics
In practice now: for arm-to-arm BP, many texts call a difference over 10 to 15 mmHg abnormal.
Work it out
Supine: 128/76, HR 80. Standing: 104/70, HR 106. How many mmHg did the systolic drop?
mmHg
Worked answer: 128 minus 104 = 24 mmHg, past the 20 mmHg cutoff, and the HR rose 26. That is orthostatic hypotension: hydrate, dangle before standing, review the meds, and start fall precautions.
Concept 5 · Children and pregnancy
Kids and pregnancy change the rules
Infants and children
- HR: newborn 120 to 160. Apical, a full 60 seconds
- RR: newborn 30 to 60. Watch the belly: infants breathe with the diaphragm
- Nose breathers: nasal congestion alone can cause distress
- BP: hypotension is a LATE sign of shock. Tachycardia comes first
- Temp: rectal is most accurate under 3 months, when any fever is an emergency
- No tympanic under 6 months: the canal is too small
Pregnancy
- HR: up 15 to 20 by the third trimester. Blood volume rises 40 to 50%
- BP: dips in the first and second trimesters, back to baseline by the third
- 140/90 or higher after 20 weeks: preeclampsia until proven otherwise. Report it
- RR: about the same. Tidal volume rises. Late dyspnea from a high diaphragm
- Temp: slightly up early. Fever of 100.4 F (38 C) or higher: investigate
Pearl: a child holds a normal BP until late. By the time it drops, the child is severely decompensated, so treat a rising HR as the warning.
Concept 6 · Abnormal temperature and heart rate
Hot, cold, fast, slow: find the cause
| Finding | Cutoff | Think |
|---|---|---|
| Fever | 100.4 F (38 C) or higher | Infection, inflammation. Raises O2 demand, HR, RR |
| Hypothermia | Under 95 F (35 C) | Exposure, late sepsis, hypothyroid. Slow HR, low LOC, bleeding risk |
| Tachycardia | Over 100 | Fever, bleeding, pain, anxiety, hypoxia, HF, anemia, drugs |
| Bradycardia | Under 60 | Athletes, digoxin, beta-blockers, high ICP, inferior MI, vagal |
Pyrogens raise the hypothalamic set point, so the body shivers and vasoconstricts to build heat. Metabolic rate climbs about 7% for each 1 F. Children 6 months to 5 years: febrile seizure risk.
Under 86 F (30 C): cardiac arrest risk. Rewarm slowly, because rapid rewarming triggers dysrhythmias. A client is not dead until warm and dead.
Dizziness, syncope, hypotension. Atropine is first line. Other causes: hypothyroidism, hypothermia, and vagal triggers such as bearing down or suctioning.
In practice now: the AHA treats bradycardia that is typically under 50 when it causes symptoms.
Pearl: HR 55 in a marathon runner is normal. On digoxin, it is a toxicity flag. With a widening pulse pressure and irregular breathing, it is Cushing's triad.
Concept 7 · Abnormal blood pressure
High, low, and the crisis line
Hypertension
- 130/80 or higher (ACC/AHA) or 140/90 or higher (JNC 8)
- Essential: no clear cause, 90 to 95% of cases
- Secondary: renal disease, pheochromocytoma, Cushing syndrome, coarctation
- Crisis: over 180/120 with organ damage. IV antihypertensives
Hypotension
- Systolic under 90, or a drop of more than 30 from baseline
- Top cause: hypovolemia (bleeding, dehydration)
- Also: sepsis, pump failure, anaphylaxis, antihypertensives, opioids
- End result: poor tissue perfusion
Fill in the numbers
In a hypertensive crisis, lower the MAP by no more than in the first hour.
Hypotension is a systolic BP under mmHg.
Concept 8 · Respirations
Count the rate, then name the pattern
Fast or slow?
Tap a cause, then tap the box it belongs in.
- Kussmaul
- Deep and rapid: metabolic acidosis, DKA
- Cheyne-Stokes
- Builds, fades, then apnea: brainstem damage, HF, near death
- Biot's
- Irregular with apnea: high ICP, meningitis
Quick check 2 of 4
A client has a morphine PCA after abdominal surgery. Which finding needs the most urgent action?
Slow breathing plus sedation is opioid toxicity until proven otherwise. Stop the PCA, stimulate the client, give naloxone per protocol (keep it at the bedside for every PCA), apply oxygen, and notify the provider. HR 62 and BP 108/66 are acceptable after surgery.
Concept 9 · Cushing's triad
Wide, slow, irregular: the brainstem is in trouble
The triad
- Hypertension, widening pulse pressure: systolic climbs, diastolic holds or drops
- Bradycardia: the Cushing reflex as the brainstem is compressed
- Irregular respirations: the pattern breaks down toward apnea
- A LATE sign of rising ICP: herniation is imminent
Act now: HOB 30 degrees, head midline, notify neurosurgery STAT. Anticipate mannitol or hypertonic saline. Brief hyperventilation (PaCO2 30 to 35) is only a bridge, per order.
Quick check 3 of 4
A client with a traumatic brain injury has BP 178/62, HR 48, and irregular, labored breathing. The best interpretation is:
178 minus 62 is a pulse pressure of 116, far wider than the normal of about 40. With bradycardia and irregular breathing, that is Cushing's triad: brainstem compression and impending herniation. Hypovolemic shock is the opposite pattern: fast HR and low BP.
Concept 10 · Shock
Every shock is fast, except one
Match the shock to its signature
Hypovolemic: IV fluids, blood, stop the bleeding. Cardiogenic: dobutamine, vasopressors, cautious diuretics, IABP. Septic: aggressive fluids and antibiotics within 1 hour; late septic shock turns cool and mottled. Anaphylactic: epinephrine IM in the anterolateral thigh first, then fluids, antihistamines, steroids, airway. Neurogenic: fluids, vasopressors (phenylephrine), atropine for the slow HR.
Pearl: tachycardia is the body's first response to almost every crisis: bleeding, infection, pain, hypoxia, fever. Never dismiss an unexplained rise, even with a normal BP.
Concept 11 · Trends
The heart talks first, the brain talks last
Put the deterioration cascade in order
Pearl: RR is the most undervalued vital sign. A change in rate is the best single predictor of cardiac arrest on a med-surg unit.
Quick check 4 of 4
Over 3 hours after surgery: HR 82, 96, 114. BP 128/76, 122/70, 110/64. RR 16, 20, 24. What is the best action?
Rising HR, falling BP, and climbing RR is an early hemorrhage pattern, even with a BP that looks acceptable. The trend is the alarm. Pain medicine can mask the tachycardia, opioids can drop the BP, and another hour is more blood lost.
Concept 12 · Rapid response and SBAR
No order needed to call for help
Common rapid response triggers
- HR under 40 or over 130. RR under 8 or over 28
- Systolic under 90. SpO2 under 90% despite oxygen
- Acute change in mental status, chest pain, seizure
- Nurse concern: enough on its own
- Early warning scores (MEWS): points for HR, RR, BP, temp, LOC. Higher score, higher acuity. Cutoffs vary by facility
Match each SBAR part to the line
Concept 13 · Escalation and frequency
Some numbers can't wait, and checks can go up anytime
- Temperature
- Over 104 F (40 C) or under 95 F (35 C)
- Blood pressure
- Systolic over 200, diastolic over 120, or a sudden change over 30
- Rhythm
- Any new dysrhythmia
- LOC
- Any acute change: new confusion, unresponsive
Vital sign frequency
- Stable: every 4 to 8 hours med-surg, every 1 to 2 hours step-down, continuous in ICU
- Post-op: every 15 min x4, every 30 min x2, every hour x4, then every 4 hours
- Blood transfusion: every 15 minutes for the first 15 minutes, then per policy
- Increase anytime: a trend, a new VS-altering drug, new symptoms. Document why
Pearl: no order needed to start oxygen per protocol, call a rapid response, take orthostatic vitals, or check vitals more often.
Decide it
The quiet bleed
Back to Ms. K · 1400 · restless
You are at the bedside. She is pale, her skin is cool, and she wants another cup of water.
The 118/72 came from a standard cuff on a large arm. What first?
Right. A small cuff reads falsely high. With the right cuff: 102/64.
The reading isn't trustworthy, and the trend matters more than any single number.
Same wrong cuff, same falsely high number.
BP 102/64, HR 108, RR 22, restless, cool skin. What now?
Pain medicine can mask the tachycardia, opioids drop the BP further, and an hour of bleeding is too long.
Right. Rising HR and RR, a falling BP, and a change in LOC after surgery is bleeding until proven otherwise. No order is needed to call.
Checking more often is a nursing judgment call. So is a rapid response.
The surgeon calls back. How do you open?
That buries the trend, and the surgeon may not come.
No data and no recommendation. Lead with the numbers and say what you need.
Right. Situation, background, assessment, recommendation: the surgeon hears the trend and what you need.
How it ends
- Stat CBC shows a falling hemoglobin. Oxygen on, fluids through a large-bore IV, type and crossmatch sent
- Back to the OR for a bleeding vessel
- Alert and stable by evening. The early call made the difference
Lock it in
Three hooks to carry into the exam
Two more
- Small cuff, big number: a too-small cuff, or an arm below the heart, reads falsely high
- Wide, slow, irregular: widening pulse pressure, bradycardia, and odd breathing is Cushing's triad
Rapid fire
A BP cuff that is too large gives a falsely high reading.
Too large reads falsely low. Too small reads falsely high.
Neurogenic shock causes bradycardia.
Loss of sympathetic tone makes it the one slow shock, with warm, dry skin.
The nurse needs a provider order to call a rapid response.
Any nurse can call one, including for plain concern.
Hypotension is a late sign of shock in children.
Children compensate with tachycardia first. A falling BP means severe decompensation.
A tympanic temperature is fine for a 2-month-old.
Not under 6 months: the ear canal is too small. Rectal is most accurate under 3 months.
NCLEX traps
What the exam will try to trick you with
Trend it. 72 to 98 in 4 hours is a 36% rise. Compare to the client's baseline, not just the textbook range.
Too late. BP holds until compensation fails. Act on the rising HR and RR.
Wrong pattern. Neurogenic shock is slow, warm, and dry. Cool, clammy, and fast is hypovolemia: look for bleeding.
Don't. Clients change their breathing when they know. Count while you appear to take the pulse.
No. Increasing the frequency is nursing judgment. Waiting for an order while a client declines is a failure of judgment. Document why.
Cheat card
The whole lesson on one card
Normals
- Temp 97.8 to 99.1 F
- HR 60 to 100, RR 12 to 20
- BP under 120/80
- SpO2 95 to 100%
Technique
- Cuff width 40% of the arm
- Small cuff = falsely high
- Apical before digoxin, full minute
- Count RR without telling
Danger patterns
- Cushing's: wide PP, slow HR, odd RR
- Neurogenic shock: slow and warm
- Hypovolemic: fast, cool, clammy
- Orthostatic: drop of 20 systolic or 10 diastolic
Trends
- HR rises first
- RR: best predictor of arrest
- BP drops late, LOC last
- Rapid response needs no order
The printable version is in the Cheat Sheets library.
Lesson quiz · 1 of 5
Before giving digoxin 0.125 mg to an adult, which finding means the nurse holds it and notifies the provider?
Digoxin slows the heart, and an apical rate under 60 in an adult is a hold. The check before digoxin is always the apical pulse for a full minute, so a radial reading is the wrong assessment, and 64 would be above the cutoff anyway.
Lesson quiz · 2 of 5
A dizzy client measures supine BP 136/78, HR 72, and standing BP 108/60, HR 98. The best interpretation is:
Systolic fell 28 mmHg and HR rose 26, so both criteria are met. Think dehydration, bleeding, bed rest, or drugs, and teach the client to rise slowly with fall precautions. The HR rise is compensation, not an arrhythmia.
Lesson quiz · 3 of 5
After a car crash: HR 128, BP 86/54, RR 26, SpO2 96%, skin cool and clammy. Which shock does the nurse suspect first?
Fast, low, and cool and clammy after trauma is hemorrhage with compensatory vasoconstriction. Neurogenic shock would be slow with warm, dry skin, and early septic shock is warm and flushed with fever.
Lesson quiz · 4 of 5
A 4-month-old has a rectal temperature of 101.8 F. The parent says, "It's probably just teething." What is most appropriate?
Teething does not cause a true fever over 100.4 F, so this infant needs evaluation for infection such as UTI, bacteremia, or meningitis. Under 3 months any fever is an emergency. An oral reading isn't possible at this age, and rectal is the right route.
Lesson quiz · 5 of 5
A client rescued from a house fire has SpO2 98% on room air but is confused with a headache. The nurse recognizes:
Carbon monoxide poisoning makes pulse oximetry read falsely high, so a normal number can hide real hypoxia. Trust the confusion and headache over the number. Cold fingers and nail polish make readings unreliable, but they don't explain these symptoms.
Wrap-up
0 / 5
Quiz score
Back to Ms. K · 6 hours post-op
Can you trust the 118/72? No. A standard cuff on a large arm reads falsely high. With the right cuff she was 102/64, lower than it looked.
Which sign changed first? Her HR, 84 to 108, then her RR. A rising HR and RR with a falling BP and new restlessness after surgery point to bleeding.
Do you need an order to call? No. A rapid response and more frequent vitals are nursing judgment calls. Then report to the surgeon with SBAR.
Keep going