Anesthesia Anesthesia is the state of narcosis, analgesia, relaxation and loss of reflex the client is not arousable even to painful stimuli DEFINITION OF TERMS physician ANESTHESIOLOGISTtraine trained d to delive deliverr anesth anesthesi esia a and to monitor patient during surgery health care ANESTHETISTprofessional, such as a nurse anesth anestheti etist, st, who is traine trained d to delive deliverr anesthesia and to monitor the patients condition during surgery ANESTHETIC- the substance such as a chemical gas, used to induced anesthesia Effects of Anesthesia 1. To produc produce e muscle muscle relaxati relaxation on 2. Anal Analge gesi sia a 3. Loss Loss of of memo memory ry 4. Artificia Artificiall sleep (uncon (unconscio sciousnes usness) s) 5. Relieves Relieves fear and anxiety anxiety Factors considered in choice of Anesthesia Physical condition Age Presence of co-existing disease Type, site, duration of surgery Anesthesiologist’s preference Anesthesiologist’s Patient’s preference Stages of Anesthesia 1. Begi Beginn nnin ing g 2. Exci Excite teme ment nt 3. Su ical ical
4. Medu Medull llar ary y
1. BEGINNING (ONSET/INDUCTION) from anesthetic administration to loss of consciousness consciousness Assessment: Drowsy or dizzy Experie erien nce audit udito ory/vi y/visu sual al Exp hallucination Intervention: Close OR doors Keep room quiet Standby ndby pers erson to assist sist if Sta necessary 2. EXCITEMENT (DELIRIUM) consciousnes sness s to loss of Loss of consciou eyelid reflexes ASSESSMENT Increase in ANS activity Irregula larr breat breathin hing, g, shouti shouting, ng, Irregu struggling PR is rapid; RR irregular PUPILS LS:: dila dilate te and and cons constr tric ictt if PUPI exposed to light INTERVENTIONS: Strap the thighs. Secure hand on armboard not apply restraint on Do operative site
3. SURGICAL Loss of eyelid reflexes to loss of most reflexes Depression of vital function Surgical procedure is started ASSESSMENT: Unconscious Muscles are relaxed VS normal
PUPILS: Small but contract when exposed to light. INTERVENTIONS: Assist in positioning the patient. Begin prep long upon the signal of the anesthesiologist anesthesiologist
4. MEDULLARY (DANGER) Vital function too depressed until respiratory and circulatory failure Due to overdose of anesthesia Resuscitation must be done. Resuscitation ASSESSMENT: Not breathing May or may not have a heartbeat RR- Shallow Weak pulse and thready PUPILS LS:: wide widely ly dila dilate ted d and and no PUPI longer contract when exposed to light Cyanotic death INTERVENTION: Establish an airway emergency Provide equipment/material Assist in CPR
Types of anesthesia General anesthesia Loss Loss of all all sensat sensation ion and consciousness Regional or Local anesthesia Loss Loss of sensa sensatio tion n in ONE area area with with consc consciou iousne sness ss present
Type of Sedation 1. Minimal sedation anxiolysis drug induced state in which a patient can respond normally in verbal commands function and cognitive coordination may be impaired 2.Moderate sedation
sedation
conscious
depressed level of consciousness that does not impair ability to maintain a patent airway Pt. respond purposefully to verbal commands alone or accompanied by light tactile stimulation. Midazolam/Diazepam
3. Deep Sedation analgesia a drug induced state in which a patient cannot be easily aroused but can respond purposefully after repeated painful stimulation inhaled or intravenous anesthetic (halothane, Volatile Isoflurane) Gas anesthetic (Nitrous oxide)
GENERAL ANESTHESIA Blocks the pain stimulus at the cortex Total loss of consciousness and sensation amnesia, analgesia, Produces hypnosis and relaxation ADVANTAGES: Respiration and cardiac function are readily regulated since client is unconscious.
Anesthesia is adjusted to the length of the operation and the client’s age and physical status DISADVANTAGE: the respiratory and Depresses circulatory system Administered by: 1. IV INFUSION 2. INHALATION Mask Nasal Oral Tracheal IV (INTRAVENOUS) Commonly used as an induction agent before a more patent type is given Unconsciousness occurs about 30 seconds after initial IV administration 3. Brief duration of action
INTRAVENOUS ANESTHETIC AGENTS: 1. TRANQUILIZERS AND SEDATIVE HYPNOTICS (Benzodiazepines) a. Midazolam (Dormicum) b. Diazepam (Valium) c. Chlordiazepoxide (Librium) d. Droperidol (Inapsine) e. Lorazepam (Ativan ) 2. OPIOIDS (Narcotics) a. Morphine b. Meperidine HCl (Demerol) 3. NEUROLEPANALGESICS a. Fentanyl (Sublimaze) b. Sufentanil 4. DISSOCIATIVE AGENTS a. Ketamine (Ketaralac; Ketajact) 5. BARBITURATES
a. Thiopental Na (Pentothal) b. Methohexital Na (Brevital) 6. NONBARBITURATES HYPNOTICS a. Etomidate (Amidate) b. Propofol (Diprivan)
Inhalation A mixture of anesthetic liquid in volatized form or gases with oxygen BY MASK or ENDOTRACHEAL TUBE
GA Induction procedure 1. 2. 3. 4. 5.
Positioning IV line Monitoring Strap Rapid acting drugs Thiopental (Pentothal) Propofol (Diprovan) Methohexital (Brevital) 6. O2 and Gas via mask 7. Muscle relaxant ADULT: Succiniylcholine chloride (Anectine) PEDIA: Rocuronium (Zemuron) Atracurium (Tracrium) Vecuronium (Norcuron) 8. INTUBATION ▪
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KEY POINTS DURING INDUCTION! 1. Circulator should remain 2. Gentle and rapid approach 3. Avoid stimulation of the patient (mandatory) “noise avoidance”
4. Do not touch patient until anesthesiologist says it is safe to do so 5. Precaution: ECG, defib, chest stet, BP 6. Positioning: if obese elevate head to avoid pressure (protect diaphragm) 7. If hypotensive- flat 8. Children: circulator- to be less frightening stay close to the child
INHALATION AGENTS:
ANESTHETIC
1. VOLATILE LIQUIDS: a. Halothane (Fluothane) b. Methoxyflurane (Penthrane) c. Enflutane (Ethrane) d. Isoflurane (Forane) e. Sevoflurane (Ultrane) f. Desflurane (Suprane ) 2. GASES: a. Nitrous oxide
1. FIELD BLOCK – areas proximal to the incision site is injected and infiltrated a barrier (“WALL IN”) 2. PERIPHERAL NERVE BLOCK – anesthetizes individual nerves or nerve plexuses rather than all the nerves anesthetized by a field block ALONG SPINAL CORD: Blocks impulses along the spinal cord and nerve roots and may occur either in the subarachnoid or epidural space 1. SPINAL – produces a nerve block in the subarachnoid space 2. EPIDURAL – injection of local anesthetic into the spinal canal in the space surrounding the dura mater 3. CAUDAL (TRANS-SACRAL) – produces anesthesia of the perineum and occasionally, the lower abdomen
REGIONAL ANESTHESIA Produces loss of sensation in only one region of the body and does not cause loss of consciousness Blocks pain stimulus at its : 1. Origin 2. Along afferent neurons 3. Along the spinal cord Block pain stimulus at its ORIGIN 1. TOPICAL – directly applied into the area to be desensitized with the use of a solution 2. LOCAL INFILTRATION BLOCK – blocks only peripheral nerves around the area of incision ALONG AFFERENT NEURONS
LOCAL ANESTHETIC AGENTS: 1. Lidocaine (Xylocaine) Mepivacaine (Carbocaine) 2. Bupivacaine (Marcaine) 3. Etidocaine (Duranest) 4. Procaine (Novocaine)
and
5. Tetracaine (Pontocaine) REGIONAL ANESTHETIC AGENTS: 1. Procaine (Novocaine) 2. Tetracaine (Pontocaine) 3. Lidocaine (Xylocaine) 4. Bupivacaine (Marcaine)
Major Complications of General Anesthesia: 1. CARDIAC ARREST 2. RESPIRATORY DEPRESSION a. Excessive mucus b. CNS depression c. Bronchospasm/ laryngospasm 3. HYPOTENSION AND SHOCK 4. LOSS OF PROTECTIVE RESPONSE TO PAIN 5. VOMITING AND ASPIRATIONS Discomforts of Complications/ Regional Anesthesia: HYPOTENSION PREVENTION: Infuse 500-800 mL of IV if not prone to CHF INTERVENTION: Oxygen administration Vasoconstrictive drugs position 10-20 Trendelenburg mins after induction NAUSEA AND VOMITING INTERVENTION: Oxygen administration Give ephedrine, anti-emetics IVF Discomforts of Complications/ Regional Anesthesia: HEADACHE – excessive loss of CSF due to: a. Loss of large spinal fluid b. Poor hydration PREVENTION: Use of small needle
Administer IV before and after induction Flat on bed for 6 to 8 hours INTERVENTION: Apply tight abdominal binder IV administration Analgesic
RESPIRATORY PARALYSIS – happens when drug reaches upper thoracic and cervical cord in large amount or in heavy doses PREVENTION: extreme trendelenburg Avoid position before level of anesthesia sets INTERVENTION: Artificial airway
Potential adverse effects of anesthesia
NEUROLOGIC COMPLICATIONS – post operative paralysis due to: a. Unsterile needles, syringes and anesthetic medications b. Pre-existing disease of the CNS which cause the paralysis rather than the anesthesia itself PREVENTION: aseptic technique and Strict careful neurologic examination to ascertain existing neurologic diseases
Intraoperative Complications: 1. 2. 3. 4. 5. 6. 7.
(ANESTHESIA)
Hypoventilation Oral trauma Hypotension Cardiac dysrhythmia Hypothermia Peripheral nerve damage Malignant hyperpyrexia
Myocardial depression, bradycardia Nausea and vomiting anaphylaxis CNS agitation, seizures, respiratory arrest Oversedation or under sedation Agitation and disorientation Hypothermia Hypotension Malignant hyperthermia Allergic reactions and drug toxicity or reactions Cardiac dysrhythmias Trauma: laryngeal, oral, nerve, and skin, including burns Thrombosis