Vital Signs – Pulse, Respiration & Oxygen Saturation

Recommendations for Assessing Vital Signs

• Purpose of baseline collection:

  • Establish comparison data on admission.

  • Detect changes in health status.

• Frequency/Indications:

  • As per health-practitioner orders.

  • Episode-specific changes (loss of consciousness, ↑ pain, patient-reported distress).

  • Pre-/intra-/post- events:

  • Blood product transfusion.

  • Surgical or invasive diagnostics.

  • Medication administration.

• Link to clinical governance: Early recognition of deterioration aligns with National Safety & Quality Health Service Standards.

Acceptable Vital-Sign Parameters & Reportable Limits

• Respiratory Rate: Normal $12\text{–}20\;\text{bpm}$ | Tachypnoea >20 | Bradypnoea <12

• Oxygen Saturation (SpO$_2$): Normal $95\%\text{–}100\%$ | Desaturation <95\% (clinical concern when <90\%).

• Pulse: Normal $60\text{–}100\;\text{bpm}$ | Tachycardia >100 | Bradycardia <60.

• Blood Pressure (Adults):

  • Optimal: Systolic $100\text{–}120\;\text{mmHg}$, Diastolic $60\text{–}80\;\text{mmHg}$.

  • Hypertension: >140/90\;\text{mmHg}.

  • Hypotension: <100/60\;\text{mmHg}.

• Temperature: Normal $36^{\circ}\text{C}\text{–}37.5^{\circ}\text{C}$ | Hyperthermia >37.5^{\circ}\text{C} | Hypothermia <35^{\circ}\text{C}.

• Pain (0–10 scale):

  • $1\text{–}3$ mild, $4\text{–}6$ moderate, $7\text{–}10$ severe.

Pulse Rate: Definition & Equipment

• Pulse = count of arterial expansions per minute produced by cardiac systole (Johns Hopkins, 2024).

• Radial artery preferred: superficial, accessible, reliable.

• Required items:

  • Watch with second hand (or electronic timer).

  • Pen & observation chart.

  • Alcohol swabs (infection prevention).

  • Stethoscope for apical pulse when indicated.

• Patient safety: verify correct identity & explain procedure to uphold informed consent principles.

Factors Increasing Pulse (Tachycardia)

• Pathophysiology: ↓ filling time → ↓ stroke volume (SV) → ↓ cardiac output (CO).

• Contributing factors:

  • ↓ Blood pressure (compensatory mechanism).

  • Pyrexia/↑ body temperature.

  • Hypoxaemia / poor oxygenation.

  • Exercise, pain.

  • Strong emotions: fear, anger, anxiety, surprise (sympathetic surge).

  • Medications e.g., adrenaline/epinephrine.

• Clinical manifestations:

  • Shortness of breath (SOB), palpitations, chest pain.

  • Light-headedness, dizziness, fainting, sudden weakness.

Factors Decreasing Pulse (Bradycardia) & Associated Symptoms

• Definition: Pulse <60\;\text{bpm} (athletes may physiologically be $\approx40$).

• Causes:

  • Ageing: natural decline of SA-node automaticity.

  • Sleep (esp. males lower than females).

  • Hypothermia.

  • Medications: beta-blockers, digoxin.

  • Severe pain (vaso-vagal response).

  • ↑ Intracranial pressure (Cushing reflex).

  • Myocardial infarction (inferior-wall).

• Symptoms needing escalation:

  • Chest pain, confusion, excessive fatigue, near-syncope.

  • SOB, exercise intolerance.

Acceptable Pulse Rates by Age

• Newborn: $80\text{–}180\;\text{bpm}$.

• 1 y: $80\text{–}140$.

• 5–8 y: $75\text{–}120$.

• 10 y / Teen: $50\text{–}90$.

• Adult & older adult: $60\text{–}100$.

Pulse Characteristics

• Rate: numeric beats/min.

• Rhythm:

  • Regular.

  • Irregular (arrhythmia); document pattern (regularly irregular vs irregularly irregular → may indicate A-fib).

• Strength (Amplitude):

  • 0 Absent.

  • 1+ Thready.

  • 2+ Weak.

  • 3+ Normal.

  • 4+ Bounding.

• Clinical significance: Amplitude reflects SV & peripheral resistance.

Pulse Amplitude & Quality Scale

• 0 Absent – vascular occlusion/critical perfusion.

• 1+ Thready – shock/dehydration.

• 2+ Weak – decreased CO.

• 3+ Normal – expected.

• 4+ Bounding – hyperdynamic states (fever, anaemia, sepsis).

Pulse Assessment Sites (Table Summary)

• Temporal, Carotid, Apical (4th–5th ICS at LMCL), Brachial, Radial, Ulnar.

• Lower extremity: Femoral, Popliteal, Dorsalis pedis, Posterior tibial.

• Clinical selection:

  • Carotid for CPR confirmation.

  • Apical when irregular or before cardioactive drugs (e.g. digoxin).

  • Peripheral distal pulses for vascular assessment.

Pre-Assessment Considerations for Pulse

• Assess within 20 min of:

  • Environmental temperature exposure.

  • Medication intake.

  • Smoking.

  • Physical activity.

• Ensures data validity; reduces confounding sympathetic influence.

Manual Pulse Assessment Technique

• Sit/lie patient comfortably; arm supported at heart level.

• Palpate radial artery with pads of index & middle fingers; avoid thumb.

• Light pressure—avoid occlusion.

• Count beats for full $60\;\text{s}$ (or $30\;\text{s}\times2$ if regular). Irregular → always full minute & verify with apical.

• If irregular, two-nurse method: one counts apical (stethoscope), other radial to detect pulse deficit.

• Document rate, rhythm, strength, site, patient position, activity level.

• Infection control: Hand hygiene before/after, clean stethoscope with alcohol wipe.

Palpation & Auscultation Visuals (Relevance)

• Clinical pictures from Geeky Medics reinforce surface landmarks.

• Encourages anatomical orientation for OSCEs.

Measuring Respirations – Fundamentals

• Normal mechanics: gentle thoracic & abdominal rise/fall.

• Abnormal cues:

  • Accessory muscle use (intercostals, SCM, trapezius).

  • Asymmetrical chest wall, flaring nostrils, pursed lips.

  • Indicates ↑ work of breathing (WOB).

Respiratory Assessment Parameters

• Rate: Eupnoea $12\text{–}20\;\text{bpm}$ (adult).

  • Tachypnoea >20, Bradypnoea <12, Apnoea = cessation.

• Depth:

  • Normal = effortless, full expansion.

  • Shallow = minimal chest excursion (pain, splinting, restrictive disease).

• Rhythm/Pattern:

  • Regular vs irregular.

Key Breathing Patterns (Recognition & Causes)

• Tachypnoea – fever, sepsis, pain, anxiety.

• Bradypnoea – opioid overdose, head injury, hypothyroid.

• Apnoea – arrest, obstruction.

• Cheyne–Stokes – CHF, neurological injury.

• Biot’s – medullary damage.

• Kussmaul – metabolic acidosis (DKA).

• Paradoxical – flail chest, diaphragm impairment.

• Obstructive sleep apnoea – airway collapse during sleep.

• Hyperventilation – anxiety, salicylate toxicity.

• Hypoventilation – COPD retention, neuromuscular weakness.

• Dyspnoea – subjective breathlessness; multi-factorial.

Mode of Breathing & Audible Sounds

• Normal: nasal inhalation/exhalation, silent.

• Abnormal sounds: wheeze (bronchospasm), stridor (upper-airway obstruction), snoring (partial obstruction).

• Links to lung-sound video resources for auditory learning.

Assessing Accessory Muscle Use

• Observation point: stand anteriorly.

• Normal: no accessory engagement.

• Abnormal: SCM, scalene, shoulder elevation; signals respiratory distress.

Pre-Assessment Considerations for Respirations

• Wait 20 min post-exercise.

• Review patient age, smoking, meds, anxiety, ambient temperature.

• Evaluate ability to speak full sentences (indicator of gas exchange sufficiency).

Respiration Measurement Technique

• Do not announce; maintain natural breathing pattern.

• After pulse, keep fingers on radial site, switch to observing thorax while still appearing to count pulse.

• Arm placed across chest.

• Count inspiration–expiration cycles for $60\;\text{s}$ for accuracy.

• Document rate, rhythm, depth, ease, and any adventitious signs (dyspnoea, noisy breathing).

Oxygen Saturation (SpO$_2$): Concept & Equipment

• Definition: percentage of haemoglobin molecules bound with O$_2$.

• Normal: $95\%\text{–}100\%$; Acceptable clinical lower limit often $\geq92\%$ (disease specific).

• Hypoxia red-flag: <90\%.

• Device: Pulse oximeter (finger, toe, ear); non-invasive photoplethysmography.

• Real-world relevance: early hypoxia detection prevents respiratory failure & cardiac arrest.

Monitoring Oxygen Saturation – Systematic Procedure

• Hand hygiene; clean probe (infection control).

• Site selection: well-perfused finger/toe/earlobe.

• Check local circulation: pulse present, capillary refill <2\;\text{s}.

• Avoid BP cuff on same limb concurrently.

• Inspect skin: breaks, oedema, hypothermia.

• Remove nail polish/acrylics.

• Apply sensor per manufacturer spec; ensure correct alignment of emitters & photodetectors.

• Observe for stable waveform/reading; note perfusion index if available.

• Post-use: clean device, perform hand hygiene, document reading, patient position, supplemental O$_2$.

LOOK–LISTEN–FEEL Primary Survey Reinforcement

• LOOK: colour (cyanosis), diaphoresis, skin temp, LOC.

• LISTEN: breath sounds, patient’s complaints.

• FEEL: pulse quality, peripheral temp.

• Integrates ABC (Airway, Breathing, Circulation) principles from previous lectures.

Causes of Unreliable SpO$_2$ Readings – Clinical Emergencies

• Cardiac/Respiratory arrest → poor signal.

• Carboxyhaemoglobin (CO poisoning) → falsely high (device cannot differentiate).

• Low perfusion states (PVD, CAD, vasoconstriction, smoking) → falsely low.

• Nail clubbing (chronic hypoxic disease) → probe mal-fit.

Causes of Unreliable SpO$_2$ Readings – Environmental & Technical

• Bright ambient light → optical interference.

• Nail polish/acrylic: brown blocks light, blue/black absorb red → low reading.

• Motion artefact: shivering, tremors, rigors.

• Mechanical obstruction: BP cuff/tourniquet proximal to probe (occludes flow).

• Poor probe positioning, dirty sensor → erratic or low values.

Ethical, Philosophical & Practical Implications

• Accuracy in vital-sign measurement embodies the nursing virtues of diligence, beneficence, and non-maleficence.

• Data guides medication titration (e.g., opioids, antihypertensives) – errors can harm.

• Respecting cultural contexts (Acknowledgement of Country) reinforces holistic, person-centred care.

• Manual methods foster therapeutic rapport; technology complements but does not replace clinical judgement.