Local and General Anesthesia: Pharmacology Guide

1. Introduction to Clinical Pharmacology Chapter 17Anesthetic Drugs

2. Introduction to Anesthesia and Types of Anesthesia • Induced by various drugs to bring about partial or complete loss of sensation • Types of anesthesia: • Local anesthesia • Regional Anesthesia • Spinal Anesthesia • General anesthesia • Anesthesiologist • Trained physician to administer anesthesia

3. Local Anesthesia and Types #1 • Local anesthesia: • Topical anesthesia: application of the anesthesia to surface of skin, open area, mucous membrane • Local infiltration anesthesia: injection of anesthesia into tissue • Epinephrine might be used for vasoconstriction but not used on extremities • Dental procedures, suturing of small wounds, making an incision into a small area

4. Local Anesthesia and Types #2 • Local anesthesia (cont.): • Regional anesthesia: injection of anesthesia around nerves to prevent sending pain signals • Spinal anesthesia: injection of anesthesia into the subarachnoid space of the spinal cord-loss of sensation in lower abdomen and lower extremities • Conduction blocks: injection of anesthesia into or near a nerve trunk include epidural and transsacral blocks

5. Preparing Patient for Local Anesthesia • Take patient’s allergy history • Explain how anesthetic will be given and how it works • Prepare the area to be anesthetized: • Cleaning the area with antiseptic, shaving the area • Requires fasting • May administer intravenous sedative

6. Administering Local Anesthesia • Mixed with epinephrine to cause local vasoconstriction • Be aware of when to and when not to use epinephrine • Epinephrine contraindicated when used on an extremity

7. Nursing Responsibilities When Caring for Patient Receiving Local Anesthesia • Applying dressing to the appropriate surgical area • Observe area for bleeding, oozing, other problems after administration

8. Preanesthetic Drugs • Given before administration of anesthesia • May consist of one drug or a combination of drugs

9. Preanesthetic Drugs: Uses • Used to decrease anxiety and apprehension immediately before surgery • Used to decrease secretions of the upper respiratory tract • Used to lessen the incidence of nausea and vomiting during the immediate postoperative recovery period

10. Selection of Preanesthetic Drugs • May consist of one or more drugs • Opioid agonists or barbiturate/antianxiety agents may be given to relax the patient-by depressing CNS • Antiemetics given to prevent vomiting when coming out of sedation • Cholinergic blocking drug such as atropine is given to dry secretions in the upper respiratory tract • Drug diazepam (valium) used for preoperative sedation

11. Nursing Responsibilities #1 • Assess the physical status of the client-check the chart for lab values to ensure provider is aware of any abnormal values • Describe or explain the preparations for surgery ordered by the physician • Describe or explain immediate postoperative care • Demonstrate, describe, and explain postoperative patient activities • Emphasize the importance of pain control using PCA pump and demonstrate use of pump

12. General Anesthesia • The choice of anesthetic drug depends on: • General physical condition of the patient • Area, organ, system being operated on • Anticipated length of surgical procedure

13. Drugs Used for General Anesthesia #1 • Barbiturates and similar agents: • Methohexital; etomidate; propofol • Benzodiazepines: midazolam- • a short-acting benzodiazepine CNS depressant, is used as a preanesthetic drug to relieve anxiety (not prevent vomiting); for induction of anesthesia; for conscious sedation before minor procedures, such as endoscopy; and to supplement nitrous oxide and oxygen for short surgical procedures • Ketamine- • rapid-acting general anesthetic ketamine will exhibit profound analgesia, cardiovascular stimulation, respiratory stimulation, and enhanced skeletal muscle tone • Gases and volatile liquids: • Nitrous oxide; sevoflurane (Ultane); isoflurane (Forane); desflurane (Suprane)

14. Drugs used for General Anesthesia #2 • Opioids • Analgesic fentanyl; droperidol; remifentanil; neuroleptic drug • Skeletal muscle relaxants-help produce relaxation of skeletal muscles during certain types of surgeries involving the chest or abdomen and are used to facilitate the insertion of an endotracheal tube • Anectine; Nimbex

15. Stages of General Anesthesia • Stage I: Analgesia; Anesthesia • Stage II: Delirium and excitement • Stage III: Surgical analgesia • Stage IV: Respiratory paralysis

16. Nursing Responsibilities #2 • Preanesthesia • Performing the required tasks and procedures as prescribed • Checking the chart for any recent, abnormal laboratory tests • Placing a list of known or suspected drug allergies • Administering the preanesthetic drug

17. Nursing Responsibilities #3 • Postanesthesia • Admitting the patient to the unit according to hospital procedure or policy • Positioning the patientto prevent aspiration of vomitus and secretions • Checking the airway for patency, assessing the respiratory status, respiratory tract for irritation, and giving oxygen as needed

18. Nursing Responsibilities #4 • Postanesthesia (cont.) • Check blood pressure and pulse, IV lines, catheters, drainage tubes, surgical dressings, and casts • Review the patient’s surgical and anesthesia records • Monitor the blood pressure, pulse, and respiratory rate every 5 to 15 minutes until the patientis discharged from the area

19. Nursing Responsibilities #5 • Postanesthesia (cont.) • Check the patient every 5 to 15 minutes for emergence from anesthesia. Suctioning is provided as needed • Exercise caution in administering opioids • Discharge the patientfrom the area to his or her room or other specified area

20. Question #1 • Is the following statement true or false? • Anesthesia is the loss of feeling or sensation.

21. Answer to Question #1 • True • Anesthesia is the loss of feeling or sensation. Local and general anesthesia are provided for pain relief and to perform otherwise painful procedures.

22. Question #2 • Is the following statement true or false? • General anesthesia includes topical, local infiltration, and regional pain relief and is used when dealing with a specific area of the body and the patient can remain conscious.

23. Answer to Question #2 • False • Local anesthesia includes topical, local infiltration, and regional pain relief and is used when dealing with a specific area of the body and the patient can remain conscious. General anesthesia requires multiple drugs and stages to achieve a state where surgical procedures can be performed without pain, movement, or memory.

24. Question #3 • Is the following statement true or false? • Nursing responsibilities include tasks to assist, maintain, and recover a patient who has been given an anesthetic.

25. Answer to Question #3 • True • Nursing responsibilities includes tasks to assist, maintain, and recover a patient who has been given an anesthetic.