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PTP 546 Module 15 Pharmacology of Anesthetics. Jayne Hansche Lobert, MS, RN, ACNS-BC, NP. Pharmacology of Anesthetics. Anesthetic Agents Characteristics Produce loss of consciousness and sensation Provide amnesia Relax skeletal muscles Inhibit sensory and autonomic reflexes
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PTP 546Module 15Pharmacology of Anesthetics Jayne Hansche Lobert, MS, RN, ACNS-BC, NP Lobert
Pharmacology of Anesthetics • Anesthetic Agents • Characteristics • Produce loss of consciousness and sensation • Provide amnesia • Relax skeletal muscles • Inhibit sensory and autonomic reflexes • Possess minimal side effects • Rapid onset of anesthesia Lobert
Pharmacology of Anesthetics • Stages of Anesthesia • Stage I: Analgesia • Somewhat aware but begins to lose somatic sensation • Stage II: Excitement/Delirium • Appearance of agitation and restlessness • Stage III: Surgical Anesthesia • Overall goal is to reach this stage quickly and maintain this stage for the duration of the surgery • Stage IV: Medullary Paralysis • Reduction of Vitals: cessation of spontaneous respirations; BP issues cardiopulmonary collapse • Would require intensive support Lobert
Pharmacology of Anesthetics • General Anesthetics • Inhaled Anesthetics • Volatile Liquids: Desflurane; Isoflurane • Gas: Nitrous Oxide • Intravenous Anesthetics • Barbiturates • Benzodiazepines • Opioids • Ketamine • Propofol Lobert
Pharmacology of Anesthetics • Pharmacokinetics of General Anesthesia • Route: • IV or Inhaled • Distribution: • Widely distributed throughout body • Highly lipid soluble deposits in adipose tissues • Metabolism & Excretion: • Via Liver and Lungs Lobert
Pharmacology of Anesthetics • General Anesthetics • Action: inhibit neuronal activity throughout the CNS unconsciousness and amnesia; produces immobility and inhibits motor responses to painful stimuli • Therapeutic Effect: anesthesia allows for surgical intervention • Side Effects: residual effects may be associated with length of anesthesia, dose, age, adipose tissues Lobert
Pharmacology of Anesthetics • Local Anesthetics • Ex: Bupivacaine (Marcaine); Lidocaine (Xylocaine) • Action: drug produces a loss of sensation in the specific body part or region • Therapeutic Effect and Clinical Use: • Topical Administration & Transdermal administration • Infiltration anesthesia: injection into local tissues to be numbed • Peripheral nerve block: brachial plexus catheters with ropivacaine during and following shoulder arthroplasty • Central neural blockade: injectio into epidural/intrathecal/ spinal sac • Sympathetic block • Intravenous regional anesthesia/block: ex: veins drained and filled with anesthetic: numbing distal to extermity, example hand surgery. Lobert
Pharmacology of Anesthetics • Adjuvants in General Anesthesia • Preop Medications • Barbiturates: decreases level of consciousness very quickly • Benzodiazepines: decrease anxiety • Opioids • Antihistamines • Antacids: position in surgery, no acid refulx. • Anticholinergics- decrease secretions to keep from aspirating on own spit. Lobert
Pharmacology of Anesthetics • Adjuvants in General Anesthesia • Neuromuscular Blockers (paralyzing agents) • Nondepolarizing Blockers • Pancuronium (Pavulon); Vecuronium (Norcuron) • Depolarizing Blockers • Succinylcholine (Anectine) • Action: complete muscle paralysis; no analgesia; noanesthesia. • Side Effects: residual paralysis Lobert
Pharmacology of Anesthetics • Local Anesthetics • Side Effects: • Extension of loss of motor function • Potential for systemic effect • CNS symptoms somnolence, confusion, agitation and excitation • CV symptoms Lobert