Unit 10: Central Nervous System

Overview

• Focus on the Central Nervous System (CNS).
• Unit 11 will continue with the Peripheral Nervous System.
• Key topics: Sedatives and Hypnotics.

Sedatives vs. Hypnotics

• Sedatives:
  • Inhibit CNS, induce relaxation, decrease anxiety.
  • At higher doses, can cause sedation.
• Hypnotics:
  • More potent, induce sleep and coma.

Precautions for Sedatives and Hypnotics

• Monitor level of consciousness and respiratory insufficiency.
• Risk for injury due to changes in consciousness.

Nursing Actions

• Assess therapeutic and side effects.
• Monitor consciousness, respiratory function, and blood pressure.
• Ensure safety: Side rails up, call light in reach.

Patient Education

• Inform about drug information, levels, and potential issues.
• Opioids can cause low BP, respiratory depression, and altered consciousness.
• Risks of physical and psychological dependence and withdrawal symptoms.

Classes of CNS Depressants

Barbiturates

• Effects: Decrease nerve transmission, increase seizure threshold.
• Dose-dependent actions:
  • Low doses: Anti-anxiety, sedation.
  • Moderate: Anti-seizure.
  • High: Anesthesia, induce coma.
• Not for sleep induction: Deprives REM sleep, can cause psychosis.
• Side Effects: Decreased respiratory rate, blood pressure, lethargy.
• Nursing Actions:
  • Know narrow therapeutic range.
  • Monitor drug levels.
• Example: Phenobarbital (Therapeutic level: 10-40 µg/mL).

Benzodiazepines

• Effects: CNS depressants, treat anxiety, insomnia, muscle relaxation.
• Side Effects: Headache, drowsiness, hangover effect, paradoxical excitement.
• Nursing Actions:
  • Assess use, educate on safety.
  • Reversal agent: Flumazenil.
• Examples:
  • Lorazepam: For panic attacks, anxiety, seizures.
  • Midazolam: Amnesiac effect, used in outpatient procedures.

Non-Benzodiazepines

• Similarities to Benzos: Less disruption of sleep, lack sedative and dependency potential.
• Effects: Anxiolytic, treat insomnia.
• Side Effects: Vary by medication.
• Nursing Actions:
  • Safety with Zolpidem (Ambien).
  • Dietary guidelines with Buspirone (Buspar).
• Examples:
  • Zolpidem: Aids in sleep induction.
  • Buspirone: Decreases anxiety with less drowsiness.