Overview
This lecture covers the physical, cognitive, and psychosocial changes that occur throughout the human lifespan, with emphasis on how these developmental stages impact assessment and care in emergency medical situations.
Vital Signs & Lifespan Changes
- Younger patients have faster pulse and respiratory rates; heart rate and breathing slow with age.
- Blood pressure increases with age.
- Normal vital signs vary significantly by age group.
Neonates and Infants (Birth–1 Year)
- Neonates: Birth to 1 month; Infants: 1 month to 1 year.
- Lose 5–10% body weight in first week; regain by week 2, double by 4–6 months, triple by 1 year.
- Transition from fetal to independent circulation occurs at birth.
- Neonates are nose breathers; infants are prone to airway obstruction due to anatomical differences.
- Immature respiratory muscles and limited alveoli; fragile lungs susceptible to barotrauma.
- Key reflexes: Moro (startle), palmar grasp, rooting, sucking.
- Fontanelles (soft spots) close by 3 months (posterior) and 9–18 months (anterior); depression/bulging indicates dehydration or increased pressure.
- Communication is primarily through crying; bonding and attachment critical for trust development.
Toddlers (1–3 Years) and Preschoolers (3–6 Years)
- Cardiovascular system similar to adults; lung and immune system continue to mature.
- Loss of passive immunity; frequent viral infections promote acquired immunity.
- Neuromuscular development progresses; fine motor skills and muscle mass increase.
- Renal maturation allows for toilet training by around 28 months.
- Psychosocially, focus on autonomy vs shame/doubt; separation anxiety peaks at 10–18 months.
- Language skills and social interaction with peers advance rapidly.
School-Age Children (6–12 Years)
- Rapid physical growth; permanent teeth replace baby teeth.
- Brain activity increases; self-concept and self-esteem develop.
- Moral reasoning advances from pre-conventional (based on consequences) to potentially post-conventional (personal ethics).
Adolescents (12–18 Years)
- Adult-like vital signs; experience 2–3 year growth spurts.
- Secondary sexual characteristics develop; reproductive maturity achieved.
- Seek independence, peer relationships, and self-identity; risk-taking behavior may increase.
- Development of personal ethics and increasing emotional complexity.
Early Adults (19–40 Years)
- Reach physical peak at 19–25 years; subtle signs of aging appear later.
- Habits formed can impact long-term health.
- Psychosocial focus on career and family; period of psychological stability despite life stress.
Middle Adults (41–60 Years)
- Increased risk for chronic health issues (vision, hearing loss, cancer, menopause).
- Adjustments to life roles, including caring for aging parents and coping with empty nest syndrome.
- Health is generally stable with proper habits.
Older Adults (61+ Years)
- Life expectancy now averages 78 years.
- Cardiovascular system declines (atherosclerosis, reduced cardiac output).
- Respiratory, renal, digestive, and endocrine functions deteriorate; increased risk of infections and nutritional issues.
- Nervous system slows, leading to sensory deficits and fall risk.
- Social and psychological issues include financial concerns, isolation, and coping with mortality; many remain active and independent.
Key Terms & Definitions
- Neonate — infant from birth to 1 month.
- Fontanelle — soft spots between cranial bones in infants.
- Barotrauma — injury to the lungs from excessive pressure.
- Atherosclerosis — buildup of cholesterol and calcium in blood vessels.
- Passive Immunity — immunity acquired from mother (placenta or breast milk).
- Self-concept — perception of oneself.
- Self-esteem — feelings about oneself and social standing.
Action Items / Next Steps
- Review Table 7-1 and 7-2 for normal vital signs and psychosocial milestones by age group.
- Read Chapter 34 on Obstetrics and Neonatal Care for details on the neonatal period.
- Study developmental milestones to inform patient assessment across age groups.