1. Anesthesia

2. Anesthesia From Greek anaisthesis means ”not sensation”
Listed in Bailey´s English Dictionary 1721.
When the effect of ether was discovered”anesthesia” used as a name for the new phenomenon.

3. Basic Principles of Anesthesia
Anesthesia defined as the abolition of sensation
Analgesia defined as the abolition of pain
“Triad of General Anesthesia”
need for unconsciousness
need for analgesia
need for muscle relaxation

4. History of Anesthesia

5. History of Anesthesia Ether synthesized in 1540 by Cordus
Ether used as anesthetic in 1842 by Dr. Crawford W. Long
Ether publicized as anesthetic in 1846 by Dr. William Morton
Chloroform used as anesthetic in 1853 by Dr. John Snow

6. History of Anesthesia Endotracheal tube discovered in 1878
Local anesthesia with cocaine in 1885
Thiopental first used in 1934
Curare first used in opened the “Age of Anesthesia”

7. Anesthesiologists care for the surgical patient in the preoperative, intraoperative, and postoperative period . Important patient care decisions reflect the preoperative evaluation, creating the anesthesia plan, preparing the operating room, and managing the intraoperative anesthetic.

9. Preoperative Evaluation
The goals of preoperative evaluation include assessing the risk of coexisting diseases, modifying risks, addressing patients' concerns, and discussing options for anesthesia care.

10. What is the indication for the proposed surgery
What is the indication for the proposed surgery? It is elective or an emergency? The indication for surgery may have particular anesthetic implications. For example, a patient requiring esophageal fundoplication will likely have severe gastroesophageal reflux disease, which may require modification of the anesthesia plan (e.g., preoperative non particulate antacid, intraoperative rapid sequence induction of anesthesia).

11. What are the inherent risk of this surgery
What are the inherent risk of this surgery? Surgical procedures have different inherent risks. For example, a patient undergoing coronary artery bypass graft has a significant risk of problems such as death, stroke, or myocardial infarction. A patient undergoing cataract extraction has a low risk of major organ damage.

12. Does the patient have coexisting medical problems
Does the patient have coexisting medical problems? Does the surgery or anesthesia care plan need to be modified because of them?

13. Has the patient had anesthesia before
Has the patient had anesthesia before? Were there Complication such as difficult airway management? Does the patient have risk factor for difficult airway management?

14. Creating the Anesthesia Plan
After the preoperative evaluation, the anesthesia plan can be completed. The plan should list drug choices and doses in detail, as well as anticipated problems .Many variations on a given plan may be acceptable, but the trainee and the supervising anesthesiologist should agree in advance on the details.

18. Preparing the Operating Room
After determining the anesthesia plan, the trainee must prepare the operating room .

22. Anesthesia Providers
Anesthesiologist ( aphysician with 4 or more yearsof speciality training in anesthesiology after medical school)
Certified registered nurse anesthetist (CRNA), working under the direction and supervision of an anesthesiologist or a physician
CRNA must have 2 years of training in anesthesia

23. Patient Safety
Patient risk and safety are concerns during surgery and anesthesia .
Data from a number of studies of death caused by anesthesia indicate a death rate ranging from 1 per 20,000-35,000.
A fourfoulded decline over the last 30 years even though surgical procedures are undertaken on increasingly sicker and much higher risk patients than in the past.
Awareness of potential problems and constant vigilance (the process of paying close and continuous attention) are crucial to good patient care.

24. Preoperative preparation patient evaluation
Anaesthesiologist:
reviews the patient´s chart,
evaluate the laboratory data and diagnostic studies such as electrocardiogram and chest x-ray,
verify the surgical procedure,
examins the patient,
discuss the options for anesthesia and the attendant risks and
ordered premedication if appropriate

25. The physical status classification
Developed by the American Society of Anesthesiologist (ASA) to provide uniform guidelines for anesthesiologists.
It is an evaluation of anesthetic morbidity and mortality related to the extent of systemic diseases, physiological dysfunction, and anatomic abnormalities.
Intraoperative difficulties occur more frequently with patients who have a poor physical status classification.

27. Choice of anesthesia
The patient´s understanding and wishes regarding the type of anesthesia that could be used
The type and duration of the surgical procedure
The patients´s physiologic status and stability
The presence and severity of coexisting disease
The patient´s mental and psychologic status
The postoperative recovery from various kinds of anesthesia
Options for management of postoperative pain
Any particular requiremets of the surgeon
There is major and minor surgery but only major anesthesia

28. Types of anesthesia care General Anesthesia
Reversible, unconscious state is characterised by amnesia (sleep, hypnosis or basal narcosis), analgesia (freedom from pain) depression of reflexes, muscle relaxation
Put to sleep

29. Types of anesthesia care Regional Anesthesia
A local anethetic is injected to block or ansthetize a nerve or nerve fibers
Implies a major nerve block administered by an anesthesiologist (such as spinal, epidural, caudal, or major peripheral block)

30. Types of anesthesia care monitered anesthesia care
Infiltration of the surgical site with a local anesthesia is performed by the surgeon
The anasthesiologist may supplement the local anesthesia with intravenous drugs that provide systemic analgesia and sedation and depress the response of the patient´s autonomic nervous system

31. Types of anesthesia care local anesthesia
Employed for minor procedures in which the surgical site is infiltrated with a local anesthetic such as lidocaine or bupivacaine
A perioperative nurse usually monitors the patient´s vital signs
May inject intravenous sedatives or analgesic drugs

32. Premedication Purpose: to sedate the patient and reduce anxiety
Classified as sedatives and hypnotics, tranquilizers, analgesic or narcotics and anticholinergics
Antiacid or an H2receptor-blockingdrug such as cimitidine (tagamet) or ranitidine (Zantac) to decrease gastric acid production and make the gastric contents less acidic
If aspiration occur this premedication decreases the resultant pulmonary damage
Given minutes before surgery, or may be given i.v. After the pat. arrives in the surgical suite
NPO for a minimum of 6 hours before elective surgery
Not given to elderly people or ambulatory patients because residual effects of the drugs are present long after the pat. have been discharged and gone home

33. Perioperative monitoring
Undergeneral anesthesia: monitoring
Inspired oxygen analyzer(FiO2) which calibrated to room air and 100% oxygen on a daily basis
Low pressure disconnect alarm, which senses pressure in the expiratory limb of the patient circuit
Inspiratory pressure
Respirometer (these four devices are an integral part of most modern anesthesia machine
ECG
BP-automated unit
Heart rate
Precordial or esophagel stethoscope
Temp

34. Perioperative monitoring
Pulse oximeters
End tidal carbon dioxide (ECO2)
Peripheral nerve stimulator if muscle relaxants are used
Foly catheter
For selected patint with a potential risk of venous air embolism a doppler probe may placed over the right atrium
Invasive: arterial pressure mesurements, central venous pressure
Pulmonary artery catheter and continous mixed venous oxygen saturation measured

35. Perioperative monitoring
For special conditions other monitors as transesophageal echocardiography
Electroencephalogram
Cereral or neurological may be used

36. Inhalational Anesthetic Agents
Inhalational anesthesia refers to the delivery of gases or vapors from the respiratory system to produce anesthesia
Pharmacokinetics--uptake, distribution, and elimination from the body
Pharmacodyamics-- MAC value

37. Regional Anesthesia
Defined as “a reversible loss of sensation in a specific area of the body”
Spinal anesthesia
Epidural anesthesia
IV Regional Blocks
Peripheral Nerve Blocks

38. Spinal Anesthesia
A local anesthetic agent (lidocaine, tetracaine or bupivacaine) is injected into the subarachnoid space
Spinal anesthesia is also known as a subarachnoid block
Blocks sensory and motor nerves, producing loss of sensation and temporary paralysis

39. Possible Complications of Spinal Anesthesia
Hypotension
Post-dural puncture headache (“Spinal headache”) caused by leakage of spinal fluid through the puncture hole in the dura-can be treated by blood patch
“High Spinal”- can cause temporary paralysis of respiratory muscles. Patient will need ventilator support until block wears off

40. Epidural Anesthesia
Local anesthetic agent is injected through an intervertebral space into the epidural space.
May be administered as a one-time dose, or as a continuous epidural, with a catheter inserted into the epidural space to administer anesthetic drug

41. Dr. Aidah Abu Elsoud Alkaissi Division of Intensive Care and Anaesthesiology University of Linköping Sweden

42. Complications of Epidural Anesthesia
Hypotension
Inadvertent dural puncture
Inadvertent injection of anesthetic into the subarachnoid space

43. IV Regional Blocks Also known as a Bier Block
Used on surgery of the upper extremities
Patient must have an IV inserted in the operative extremity

44. IV Regional Block
After a pneumatic tourniquet is applied to extremity, Lidocaine is injected through the IV.
Anesthesia lasts until the tourniquet is deflated at the end of the case.

45. IV Regional Blocks
IMPORTANT- to prevent an overdose of lidocaine it is important not to deflate the tourniquet quickly at the end of the procedure.

46. Peripheral Nerve Blocks
Injection of local anesthetic around a peripheral nerve
Can be used for anesthesia during surgery or for post-op pain relief
Examples: ankle block for foot surgery, supraclavicular block for post-op pain control after shoulder surgery

47. Monitored Anesthesia Care (MAC)
Generally used for short, minor procedures done under local anesthesia
Anesthesia provider monitors the patient and may provide supplemental IV sedation if indicated

48. Conscious Sedation Used for short, minor procedures
Used in the OR and outlying areas
(ER, GI Lab, etc)
Patient is monitored by a nurse and receives sedation sufficient to cause a depressed level of consciousness, but not enough to interfere with patient’s ability to maintain their airway

49. Inhalation Anesthetics
Nitrous Oxide- can cause expansion of other gases- use of N20 contraindicated in patients who have had medical gas instilled in their eye(s) during retinal detachment repair surgery

50. Inhalation Anesthetics
Cause cerebrovascular dilation and increased cerebral blood flow
Cause systemic vasodilation and decreased blood pressure
Post-op N&V
All inhalation anesthetics, except N20, can trigger malignant hyperthermia in susceptible patients

51. Intravenous Induction/Maintenance Agents
Propofol (Diprivan)- pain/burning on injection, can cause bizarre dreams
Pentothal (Sodium Thiopental)- can cause laryngospasm

52. General Anesthesia
During induction the room should be as quiet as possible
The circulator should be available to assist anesthesia provider during induction & emergence
Never move/reposition an intubated patient without coordinating the move with anesthesia first

53. General Anesthesia
Laryngospasm may happen in a patient having a procedure with general anesthesia
When laryngospasm occurs, it is usually during intubation or emergency
Assist anesthesia provider as needed- call for anesthesia back-up if necessary

54. Difficult Airway Cart
Anesthesia maintains a “Difficult Airway Cart” containing equipment & supplies for difficult intubations
This cart is stored in one of the anesthesia supply rooms
Page anesthesia tech if the cart is needed for your room

55. Cricoid Pressure or Sellick Maneuver
Used for patients at risk for aspiration during induction, due to a full stomach or other factors such as a history of reflux
Pressure on the cricoid cartilage compresses the esophagus against the cervical vertebrae and prevents reflux

56. Sellick Maneuver
Cricoid pressure is maintained, as directed by anesthesia provider, until the ETT cuff is inflated:

57. Regional Anesthesia
Circulator may need to assist anesthesia provider with positioning for spinal or epidural anesthesia.
Patient usually is positioned laterally for placement of regional anesthesia, but may be positioned sitting upright.

58. The Awake Patient
Patients undergoing surgery with regional or local anesthesia, even if sedated, may be aware of conversation and activity in room
Post sign on door to OR, “Patient is Awake” so that staff entering room will be aware that patient is conscious

59. When Patient is Awake
Limit any discussion of patient’s medical condition and prognosis
Avoid discussion of other patients & limit unnecessary conversation-- a sedated patient can easily misinterpret conversation they overhear