1. Surgical Anesthesia

2. History of Anesthesia
Derived from the Greek word ‘Anaisthesis’ meaning “lack of sensation”.
Defined today as the process used to relieve pain and suffering during surgical intervention.

3. History of Anesthesia
Early use of anesthetic substances included coca leaves and opium.
Ether was used extensively throughout the 1800’s with much success.
These practices set the groundwork for the science of anesthesia leading to newer, safer, and better agents used today.

4. History of Anesthesia

5. Anesthesia Techniques
Optimal anesthesia addresses the following areas:
Hypnosis
Anesthesia
Amnesia
Muscle relaxation
Patient positioning
Homeostasis of vital functions

6. Anesthesia Techniques
Anesthetic agents can be administered in two ways:
General anesthesia
Altering the patients level of consciousness.
Nerve conduction blockage
Preventing sensory nerve conduction

7. Anesthesia Techniques
Choice of the type of anesthesia used varies from case to case, keeping the patients safety in mind.

8. Anesthesia Techniques
ASA risk classifications:
Class 1
No organic, physical, biochemical, or psychological disturbance.
Class 2
Mild to moderate systemic disturbance.
Smokers, controlled hypertension, diabetes, mild obesity.

9. Anesthesia Techniques
ASA risk classifications:
Class 3
Severe systemic disturbance or disease.
Angina, post MI, massive obesity.
Class 4
Severe systemic disturbance that are life threatening.
Congestive heart failure, respiratory disease.

10. Anesthesia Techniques
ASA risk classifications:
Class 5
Patient has little chance for survival.
Class 6
Brain dead, organ procurement.
Emergency modifier
Applied for emergency surgery.

11. General Anesthesia
Involves an alteration in the patients perception of his environment by alterations in the level of consciousness.
Agent inhalation
Agent injection
Agent instillation

12. General Anesthesia Stages of general anesthesia: Stage I
Amnesia stage beginning with initial administration of agent until loss of consciousness.

13. General Anesthesia Stages of general anesthesia: Stage II
Excitement stage from loss of consciousness to return of regular breathing and loss of eyelid reflex.
Vomiting and laryngospasm may be seen.
May be passed through rapidly by IV induction agent.

14. General Anesthesia Stages of general anesthesia: Stage III
Surgical anesthesia stage.
Patient is unresponsive to pain and sensation. Hearing is the last sense lost.
Optimum for surgical intervention.

15. General Anesthesia Stages of general anesthesia: Stage IV
Overdose stage.
Dilated, non-reactive pupils.
If untreated, may lead to circulatory failure or death.

16. General Anesthesia Phases of general anesthesia: Induction phase
Alteration from a conscious to unconscious state.
Use of IV or inhaled agent.
Airway must be managed.
Hearing is the last sense obtunded, keep the room quiet.

17. General Anesthesia Phases of general anesthesia: Maintenance phase
Surgical intervention phase
Anesthesia provider must closely monitor all vital functions and adjust anesthetic levels as needed.

18. General Anesthesia Phases of general anesthesia: Emergence phase
Goal is to have the patient as awake as possible at the end of surgery.
Reversal agents may be needed.
Patients may be extubated when respiratory rate and gag reflex return.
Monitor for hypothermia.

19. General Anesthesia Phases of general anesthesia: Recovery phase
Patient returns to optimum level of consciousness and well being.
PACU

20. General Anesthesia Advantages
Patient is unaware of activities and noises during surgery.
Respiration rate and aspiration risks are controlled.
Muscle relaxation is easily achieved.

21. General Anesthesia Risks and complications
Aspiration of gastric contents could occur during the induction or emergence phase causing aspiration pneumonia.
Patients must be NPO for adequate number of hours prior to surgery.
Cricoid pressure (Sellick’s maneuver)

22. General Anesthesia
Cricoid pressure (Sellick’s maneuver)

23. General Anesthesia Risks and complications
Laryngospasms and bronchospasms cause rigidity in the upper respiratory tract resulting in the patient’s inability to move air in and out of the lungs.
Caused by trigger of gag reflex.
Treated with positive pressure or succinylcholine. (neuromuscular blocker)

24. General Anesthesia Risks and complications
Malignant Hyperthermia a potentially fatal hyper metabolic state of muscles.
Calcium deficiency causes skeletal muscles to contract and become rigid.
Heat, CO2, and lactic acid buildup causes a rapid increase in body temperature.

25. General Anesthesia Risks and complications
MH can be triggered by use of succinylcholine, curare, and halogenated inhalation agents.
Staff should be familiar with signs and symptoms and know the location of supplies and treatment protocol.

26. General Anesthesia Risks and complications
Treatment includes discontinuing the anesthetic agent ASAP.
Dantrolene is given by IV.
Other treatments include cooling the body by ice or chilled lavage.
Sodium bicarbonate may be given to assist with acidosis.

27. General Anesthesia Risks and complications
Mild or severe allergic reactions.
Anaphylaxis reactions are the most serious and may lead to respiratory and vascular collapse.
Strict adherence to identified patient allergies are a must.

28. General Anesthesia Risks and complications
Patients in general anesthesia are also at risk for:
Shock
Cardiac dysrhythmias
Cardiac arrest

29. Anesthetic Agents Inhalation agents
Agents inhaled and pass to the blood stream via pulmonary function.
Oxygen
Nitrous oxide
Waste gases

30. Anesthetic Agents Inhalation agents
Volatile agents are liquids whose potent evaporative vapors produce general anesthesia.
Lowering CNS, respiratory, cardiovascular, and muscle activity.

31. Anesthetic Agents Inhalation agents Halothane Enflurane Isoflurane
Desflurane
Sevoflurane

32. Intravenous agents
Provide direct access to the bloodstream and agents act quickly and are metabolized by the liver and kidneys.
Induction agents
Dissociative agents
Opioids
Sedatives/Tranquilizers
Neuromuscular blockers
Adjunctive agents
Antimuscarinic (Anticholinergic) agents

33. Intravenous agents Induction agents
Medications used to permit rapid and pleasant transition from stage 1 to stage 3.
Produce a sedation and amnesia.
May be used to maintain general anesthesia.

34. Intravenous agents Induction agents Propofol
Nicknamed “Milk of Amnesia”, due to its milky color.
Sedative/hypnotic agent with no “hang over” affects
May produce discomfort at IV site because of its alkaline nature.
Contraindicated for patients with head trauma.

35. Intravenous agents Induction agents Etomidate (Amidate)
Post-op vomiting may occur.
Thiopental sodium (Pentothal sodium)
No anesthesia or muscle relaxation.
Leaves patient with “hang over” affect.
Methohexital sodium (Brevital)
Very quick onset

36. Intravenous agents Dissociative agents
Interrupt pathways to the brain.
Patients may appear awake, but are unaware of their surroundings.
Ketamine HCL (Ketalar)
Does not relax reflexes.
Increased salivation, Intracranial/Intraocular pressure.
May cause morbid hallucinations or “flash backs”.

37. Intravenous agents Opioids
Decrease pain impulses and a feeling of euphoria.
Schedule II narcotics
Morphine sulfate
Meperidine (Demerol)
Fentanyl citrate (Sublimaze)
Sufentanil citrate (Sufenta)
Alfentanil HCL (Alfenta)
Remifentanil HCL (Ultiva)

38. Intravenous agents Naloxone HCL (Narcan)
Reverses opioid affects or overdose.
May lead to rapid onset of pain.

39. Intravenous agents Benzodiazepines (Sedative/tranquilizers)
Reduces anxiety and apprehension preoperatively.
Produces amnesic effects.
Diazepam (Valium)
Midazolam (Versed)
Droperido (Inapsine)

40. Intravenous agents Neuromuscular blockers
Interfere with the passage of impulses from motor nerves to skeletal muscles.
Monitored by a nerve stimulator
Two major categories:
Depolarizing agents
Nondepolarizing agents

41. Intravenous agents Depolarizing agents
Mimics a release of acetylcholine across the neuromuscular junction, causing muscles to contract then followed by a period of muscle fatigue.
“Fasciculation”
Succinylcholine

42. Intravenous agents Non-depolarizing agents
Work by competing for synapse receptor sites at the neuromuscular junction, preventing acetylcholine from stimulating muscle contraction.
Short, intermediate, and long acting agents.

43. Intravenous agents Non-depolarizing agents
Mivacurium chloride (Mivacron)
Vecuronium bromide (Norcuron)
Rocuronium bromide (Zemuron)
Atracurium besylate (Tracrium)
Cisatracurium besylate (Nimbex)
Tubocurarine chloride (Curare)
Pancuronium bromide (Pavulon)

44. Intravenous agents Antimuscarinic agents
Used to limit undesirable parasympathetic nervous system responses.
Salivation
Bradycardia
Atropine sulfate
Glycopyrrolate (Robinul)

45. Intravenous agents Nonsteroidal Anti-Inflammatory agents
Ketorolac (Toradol)
Given IM for moderate pain control.
Gastric Acid Management
Bicitra, Tagamet, Zantac, Reglan
Alter PH and reduce gastric volume.
Antiemetic
Reglan, Zofran, or Inapsine
Prevent or treat nausea and vomiting.

46. Adjunctive Treatments
Induced Hypothermia
Deliberate lowering of the body’s core temperature to reduce oxygen demand and waste product formation.
Light Hypothermia = 98.6oF- 89.6oF
Moderate Hypothermia = 89.6oF- 78.8oF
Deep Hypothermia = 78.8oF- 68oF
Profound Hypothermia = 68oF- below

47. Anesthesia Equipment
The primary goal during anesthesia is to keep the patient as safe as possible throughout the procedure.
The anesthesia machine and other equipment allow the surgical team to promote homeostasis, identify and physical changes, and provide early intervention, before it can become life threatening.

48. Anesthesia Equipment Anesthesia machine
Inhalation agent delivery system
Vaporizers
Respiratory support equipment
Monitoring devices
Anesthesia circuit
Tubing system providing inhalation of anesthetic agents.

49. Anesthesia Equipment Airway Delivery/Maintenance Devices
Endotracheal (ET) tubes
Provides patient’s airway.
Placed through the patients nose or mouth, between the vocal cords, and into the trachea.
May have ballooned cuff.
Place with the assistance of a stylet.

50. Anesthesia Equipment Airway Delivery/Maintenance Devices
McGill forceps
Aid in placement of nasogastric/ nasotracheal tubes.
Laryngoscope
Lighted device to expose the glottis and assist in ET tube placement.

51. Anesthesia Equipment

52. Anesthesia Equipment Airway Delivery/Maintenance Devices
Laryngeal Mask Airway (LMA)
Provides simple effective airway forming a low pressure seal around the laryngeal inlet.
Oropharyngeal and Nasal Airways
Provides unobstructed airway around a relaxed tongue.

53. Anesthesia Equipment
LMA
Oral Airway
Nasal Airway

54. Anesthesia Equipment Hypothermia/Hyperthermia Devices Bair Hugger
Warming device that uses warm air blown into a special blanket placed over the patient.
Secured with adhesive strips.
Various sizes and shapes.

55. Anesthesia Equipment

56. Anesthesia Equipment Hypothermia/Hyperthermia Devices
Warming/Cooling Blankets
Fluid Warming Devices
Rapid Infusion Pump
Infusion Control Devices

57. Anesthesia Equipment Monitoring Devices Electrocardiogram (EKG)
Noninvasive method to monitor the rate, rhythm, and electrical conduction of the heart.
Placement of electrodes
BP Monitor
Arterial/Venous Catheterization

58. Anesthesia Equipment Monitoring Devices Temperature Monitors
Skin surface monitor
Invasive monitoring
Esophageal, bladder, rectal probes.

59. Anesthesia Equipment Monitoring Devices Pulse Oximeter
Noninvasive assessment of the hemoglobin saturation levels.
Uses a pulsing absorption of light.
Placed on the fingertip, toes, earlobe, or bridge of the nose.
No nail polish.

60. Anesthesia Equipment

61. Anesthesia Equipment Monitoring Devices Bispectral Index Monitor
Capnography
Provides breath by breath analysis of expired CO2 (end tidal CO2)
Spirometry
Oxygen Analyzer

62. Anesthesia Equipment Monitoring Devices Stethoscope
Placement of ET tube.
Doppler
Uses ultrasound to assess vessels.
Peripheral Nerve Stimulator
Assess level of neuromuscular blocker.
Arterial Blood Gas (ABG)

63. Nerve Conduction Blockade
Used to prevent initiation or transmission of impulses along a nerve pathway.
Provides lack of sensation distal to, or adjacent to the injection site.
Local and Regional anesthetics
Amino Amides
Amino Esters

64. Nerve Conduction Blockade
Amino Amide
Lidocaine HCL (Xylocaine)
Most widely used. Rapid onset.
Mepivacaine HCL (Carbocaine)
Bupivacaine HCL (Marcaine)
4x as strong as Lidocaine.
Long onset, but long acting.
Etidocaine HCL (Duranest)

65. Nerve Conduction Blockade
Amino Ester
Cocaine HCL
Topical anesthetic of the upper aerodigestive tract mucosa.
Procaine HCL (Novocaine)
Tetracaine HCL (Pontocaine)

66. Nerve Conduction Blockade
Adjunctive agents
Hyaluronidase (Wydase)
Added to assist local anesthetic to distribute to the subcutaneous tissues.
Retrobulbar
Epinephrine (Adrenalin)
Vasoconstrictor
Not to be used on digits or penis.

67. Nerve Conduction Blockade
Topical Anesthesia
Provides anesthesia on mucous membranes of the upper aerodigestive tract, urethra, vagina, rectum and skin.
Cryoanesthesia
Ethyl chloride
Lidocaine
Cocaine

68. Nerve Conduction Blockade
Local Anesthesia
Injection of a nerve conduction blocking agent into surrounding tissues.
Onset and duration depend on medication used.
Epinephrine
Re-administration of addition medication may be necessary.

69. Nerve Conduction Blockade
Regional Anesthesia
Administration of anesthetic along a major nerve pathway.
Nerve plexus block
Bier block
Spinal
Epidural
Caudal

70. Nerve Conduction Blockade
Nerve Plexus Block
Injection of an anesthetic solution in an area of a major nerve plexus.
Brachial plexus
Used with IV sedation, it permits use of a lower dose.

71. Nerve Conduction Blockade
Bier block
Used on procedures of the arm of 1-hour duration or less.
Double cuffed tourniquet is applied to the arm and anesthetic is injected into a vein below the tourniquet.
Arm is exsanguinated and tourniquet is inflated, containing the anesthetic and making for a “bloodless” surgery.

72. Nerve Conduction Blockade

73. Nerve Conduction Blockade
Spinal (Intrathecal block)
Injection of anesthetic agent into the subarachnoid space.
Produces a loss of sensation below the diaphragm.
Most commonly used agent is tetracaine HCL.
Lidocaine HCL
Procaine HCL

74. Nerve Conduction Blockade
Spinal (Intrathecal block)
Circulator assists placing patient in desired position and stands by to help maintain it.
Lower lumbar area is cleansed and draped.
Local anesthetic is injection to provide comfort.
Spinal needle is placed into the subarachnoid space.
Agent is injection and patient is positioned for surgery.

75. Nerve Conduction Blockade
Factors affecting spinal anesthesia:
Patient cooperation
Position
Exposure to the intervertebral spaces.
“Mad cat” position
Agent baricity
Specific gravity
Hyperbaric = toward gravity
Isobaric = move away from gravity

76. Nerve Conduction Blockade
Advantages of Spinal Anesthesia
Patient remains conscious and in control of their own airway.
No irritation to the upper respiratory tract.
Bowel contraction.
Excellent muscle relaxant.

77. Nerve Conduction Blockade
Disadvantages of Spinal Anesthesia
Lowering of blood pressure.
Treated by large dose of IV fluids.
Spinal headache
Meningeal layer irritation due to a drop in CSF pressure.
Patient may require a blood patch.

78. Nerve Conduction Blockade
Epidural Anesthesia
Administration of an anesthetic agent via an indwelling catheter above the dura mater and is absorbed into the CSF.
Permits re-administration of additional agent as needed.
Patient position and baricity have little affect.

79. Nerve Conduction Blockade

80. Non-Traditional Anesthesia
Hypoanesthesia
Using hypnotherapy to alter the patients level of consciousness.
Acupuncture
Intense electrical stimulation in specific body areas to alter the perception of pain.
Body’s use of endorphins.

81. Team Member Roles During Anesthesia
Preoperative
Induction and Maintenance
Spinal anesthesia
Post anesthesia
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