Principles of Anesthesia

1. Principles of Anesthesia ST210 Concorde Career College

2. Objectives • Assess the action, uses, and modes of administration of drugs and anesthetic agents used in the care of the surgical patient • Recognize general terminology and abbreviations associated with anesthesia • Recognize the side effects and contraindications for the use of various anesthetic drugs

3. Objectives • Interpret factors that influence anesthesia selection for individual patients • List the equipment used during anesthesia administration • Analyze how sterile technique is used in relation to anesthesia procedures • Compare and contrast the roles of the surgical technologist and circulator during the administration of anesthesia

4. Definitions Anesthesia - From the Greek meaning lack of sensation; particularly during surgical intervention.

5. Definitions • Review • HYPNOSIS • ANESTHESIA • AMNESIA • MUSCLE RELAXATION • POSITIONING • HOMEOSTASIS

6. Anesthesia History Timeline • 1500s: Coca leaves used as local anesthetic during trephination of the skull • 1725: Ether was discovered by Spanish chemist Raymundus Lillius • 1800s: Social use of ether - “ether frolics” • 1842: Crawford W. Long may have been the first to use ether for surgical pain control, but did not publish his findings until 1848

7. Anesthesia History Timeline • 1846: William T.G. Morton performed surgery at Mass General Hospital in front of an audience • First Surgical Use of Anesthetics – Click Here • Ether Dome: Mass General Hospital • 1905: Long Island Society Anesthetists (LISA) formed • 1936: LISA changed name to ASA (American Society of Anesthesiologists)

8. Anesthesia History Timeline

9. Anesthesia History Timeline

10. Anesthesia History Timeline

11. Anesthesia Administration Two primary methods of anesthesia administration: • Inhalation Agents • Typically for General Anesthesia • Injectable Agents • Typically for Nerve Conduction Blockade, or • Regional Anesthesia

12. General Anesthesia Alteration in the patient’s level of consciousness (patient is “asleep”) Accomplished by: • Agent inhalation • Agent injection • Agent instillation

13. Nerve Conduction Blockade Prevent initiation of conduction of nerve impulses along a nerve pathway (patient is “awake”)

14. Anesthesia Selection Factors that affect selection of the type of anesthesia: • Planned procedure and estimated duration • Patient position • Age, size, and weight of the patient • Patient status (emotional, mental, and physical) • General health of the patient (comorbid conditions)

15. Anesthesia Selection Factors that affect selection of the type of anesthesia: (continued) • Medication status • Allergy status • History of substance abuse • Emergency conditions • Preference (surgeon, anesthesia provider, patient)

16. ASA Risk Classification System • Class 1 – No organic, physiological, biochemical, or psychiatric disturbance • Class 2 – Mild to moderate systemic disease or disturbance (e.g., controlled hypertension or diabetes, asthma, anemia, smoking, mild obesity, age – less than 1 or greater than 70)

17. ASA Risk Classification System • Class 3 – Severe systemic disease or disturbance (e.g., stable angina, previous MI, poorly controlled hypertension or diabetes, symptomatic respiratory disease, massive obesity) • Class 4 – Severe (life threatening) systemic disease or disturbance (e.g., unstable angina, CHF, debilitating respiratory disease, hepatorenal failure)

18. ASA Risk Classification System Class 5 – Moribund Class 6 – Brain dead E – Emergency modifier

19. Roles of the Surgical Team Members (refer to the tables on pp. 257-261) • Preoperative case management duties • Intraoperative case management duties • Postoperative case management duties

20. Anesthesia Evaluation & Preparation Preanesthetic evaluation and preparation processes • Preoperative routine • Preoperative education • Patient possessions • Preoperative procedures

21. Preoperative Routine • Enema • Nail polish and makeup • Hygiene (shower and shave) • Attire • Sedation • Call to the OR • Family visit • Identification, chart, consent, transportation, transfer...

22. Anesthesia EquipmentEquipment and techniques used to monitor the patient • Blood pressure • O2 Sat • Temperature • I&O • Heart • BIS • Respiration • SARA • Doppler • Peripheral Nerve Stimulator • ABG

23. Anesthesia Equipment Equipment and techniques used to monitor the patient Blood Pressure Sphygmomanometer (with stethoscope)

24. Anesthesia Equipment Equipment and techniques used to monitor the patient O2 Sat Pulse Oximeter

25. Anesthesia Equipment Equipment and techniques used to monitor the patient Temperature Thermometer Esophageal Stethoscope with temperature probe

26. Anesthesia Equipment Equipment and techniques used to monitor the patient I&O Intake and Output

27. Anesthesia Equipment Equipment and techniques used to monitor the patient Heart Apical Stethoscope Earpiece

28. Anesthesia Equipment Equipment and techniques used to monitor the patient Heart Electrocardiogram Electrodes

29. Anesthesia Equipment Equipment and techniques used to monitor the patient Heart Electrocardiogram Leads

30. Anesthesia Equipment Equipment and techniques used to monitor the patient Heart Electrocardiogram (ECG)

31. Anesthesia Equipment Equipment and techniques used to monitor the patient BIS Monitor (Bispectral Index)

32. Anesthesia Equipment Equipment and techniques used to monitor the patient Respiration SARA (System for Anesthetic and Respiratory Analysis)

33. Anesthesia Equipment SARA is capable of several functions including: • Capnography • Spirometry • Oxygen analysis

34. Anesthesia Equipment Equipment and techniques used to monitor the patient Doppler

35. Anesthesia Equipment Equipment and techniques used to monitor the patient Peripheral Nerve Stimulator

36. Anesthesia Equipment Equipment and techniques used to monitor the patient ABG (Arterial Blood Gas)

37. Methods of Anesthetic Administration • General • Balanced • Neuroleptanalgesia • Nerve Conduction Blockade • Regional • Local • Topical

38. Common Anesthetic Agents • Inhalation Agents • Oxygen • Nitrous oxide • Waste gases

39. Common Anesthetic Agents Oxygen • Inhalation agent • Not anesthetic agent • Necessary for life

40. Common Anesthetic Agents Nitrous Oxide • Produces analgesia and amnesia • Produces little muscle relaxation • Decreases myocardial contractility and respiratory function

41. Common Anesthetic Agents Waste gas scavenger system

42. Common Anesthetic Agents Volatile Agents • Liquids with potent evaporative vapors • CNS depression produces general anesthesia • Myocardial and respiratory depression • Decrease muscle tone

43. Volatile Agents • Halothane (Fluothane) • Enflurane (Ethrane) • Isoflurane (Forane) • Desflurane (Suprane) • Sevoflurane (Ultane)

44. Halothane • Rapid acting • Sweet odor • Nonirritating to the respiratory tree • Used for induction and maintenance

45. Enflurane • Halogenated • Sweet odor • Rapid induction • Rapid recovery • Hypotension (when not surgically stimulated) • Potentiates nondepolarizing NMB

46. Isoflurane • Rapid induction and recovery • Musty smelling • Profound respiratory depression and hypotension • Markedly potentiates NMB • Increases ICP

47. Desflurane • Halogenated • Requires heated vaporizer • Pungent aroma • Not biotransformed in the liver

48. Sevoflurane • Odorless • No irritation to respiratory tree • Causes bradycardia, hypotension, dysrhythmias, decreases cardiac output

49. Intravenous Agents • Permit rapid pleasant transition from consciousness to unconsciousness • Produce marked sedation and amnesia • Produce hypotension and respiratory depression • Some induction agents may also be used for maintenance

50. Intravenous Agents for Induction • Propofol (Diprivan) • Etomidate (Amidate) • Thiopental sodium (Pentothal Sodium) • Methohexital sodium (Brevital)