Overview of Anesthesia

The Four Stages of Anesthesia Stage I: Relaxation Biologic Response: Amnesia, Analgesia Pt Reaction: Feels drowsy and dizzy. Exaggerated hearing. Decreased sensation of pain. May appear inebriated. Nsg Actions: Close OR doors. Check for proper positioning of safety devices. Have suction available and working. Keep noise in room at a minimum. Provide emotional support for the pt by remaining at his side.

The Four Stages of Anesthesia Stage II: Excitement Biologic Response: Delirium Pt Reaction: Irregular breathing. Increased muscle tone and involuntary motor activity; may move all extremities. May vomit, hold breath, struggle (pt very susceptible to external stimuli such as a loud noise or being touched) Nsg Actions: Avoid stimulating the patient. Be available to protect extremities or to restrain the pt. Be available to assist anesthesiologist with suctioning.

The Four Stages of Anesthesia Stage III: Operative or surgical anesthesia Biologic Response: Partial to complete sensory loss. Progression to complete intercostal paralysis. Pt Reaction: Quiet. Regular thoraco-abdominal breathing. Jaw relaxed. Auditory and pain sensation lost. Moderate to maximum decrease in muscle tone. Eyelid reflex is absent. Nsg Actions: Be available to assist anesthesiologist with intubation. Validate with anesthesiologist appro. Time for skin scrub and positioning of pt. Check position of pt’s feet to ascertain they are not crossed.

The Four Stages of Anesthesia Stage IV: Danger Biologic Response: Medullary paralysis and respiratory distress. Pt Reaction: Resp. muscles paralyzed. Pupils fixed and dilated. Pulse rapid and thready. Respirations cease. Nsg Actions: Be available to assist in tx. Of cardiac or respiratory arrest. Provide emergency rug box and defibrillation. Document administration of drugs.

Common Inhalation Agents Forane : Advantage: lowers resp., good muscle relaxation, low incidence of renal or hepatic damage. Offers good cardiovascular stability. May be given to pt’s with minimal renal failure.

Common Inhalation Agents Forane : Disadvantage: Pungent odor Produces more coughing expensive

Common Inhalation Agents Halothane : Advantage: Rarely irritates the brynx Does not increase respiratory secretions

Common Inhalation Agents Halothane : Disadvantage: Cases of hepatitis have been reported after administration Should not be administered to patients with abnormal liver fx.

Common Inhalation Agents Ethrane : Advantage: Rapid induction Rapid recovery with minimal after effects

Common Inhalation Agents Ethrane : Disadvantage: Respiration and blood pressure are progressively depressed with deepening anesthesia Severe renal failure is a contraindication to use. Seizure activity asso. with use. Not to be administered to pt with history of seizures.

Common Inhalation Agents Desflurane : Advantage: Allows much faster induction and emergence Offers good cardiovascular stability

Common Inhalation Agents Desflurane : Disadvantage: Strong odor

Common Inhalation Agents N2O Inorganic gas of slight potency, supports combustions when combined with oxygen. Only gas still in use for anesthesia

Common Inhalation Agents N2O Advantage: rapid uptake and elimination

Common Inhalation Agents N2O Disadvantage: no muscle relaxation, possible excitement or laryngospasm, hypoxia a hazard

Common Inhalation Agents N2O Use: because it lacks potency, N2O is rarely used alone, but as an adjunct to barbiturates, narcotics, and other drugs.

Intravenous Anesthetic Agents Because removal of drug from circulation is impossible, safety in use is related to metabolism.

Intravenous Anesthetic Agents Barbituates: Sodium Pentothal, Brevital Important Facts: Do not produce relief from pain, only marked sedation, amnesia, hypnosis. Repeated administration has accumulative, prolonged effect. Extravasation can cause thrombophlebitis, nerve injury, tissue necrosis.

Intravenous Anesthetic Agents Diprivan: Sedative, hypnotic Important Facts: Used for rapid induction and maintenance of anesthesia for short periods of time. Used for general anesthesia for ambulatory surgery patients.

Intravenous Anesthetic Agents High Dose Narcotics: Following high dose narcotic anesthesia patients are: –awake, –pain free, –with adequate, though not good ventilation

Intravenous Anesthetic Agents High Dose Narcotics: Opiods: Fentanyl (Sublimase): 70 times more potent than Morphine. Sufenta: 5 times more potent than Fentanyl, 625 times more potent than Morphine. Demerol: causes myocardial depression and tachycardia, 1000 times less potent than Fentanyl.

Intravenous Anesthetic Agents High Dose Narcotics: Clinical signs of narcotic toxicity: Pinpoint pupils Depressed respirations Reduced consciousness

Intravenous Anesthetic Agents High Dose Narcotics: Narcotic antagonist given to reverse narcotic-induced hypoventilation. Narcan

Intravenous Anesthetic Agents Nondepolarizing Neuromuscular blockers: Act on enzymes to prevent muscle contraction.

Intravenous Anesthetic Agents Nondepolarizing Neuromuscular blockers: 1.Curare: poison arrows made by South American Indians. Caused respiratory paralysis. 2.Pavulon: 5 times more potent than Curare. 3.Norcuron: shorter duration of action, more potent than Pavulon. 4.Tracrium: intermediate action about 30 minutes. Advantage to liver and renal disease pt because metabolizes more quickly.

Regional Anesthesia Spinal Anesthesia Agent is injected into the cerebrospinal fluid (CSF) in the subarachnoid space using a lumbar interspace in the vertebral column.

Regional Anesthesia Spinal Anesthesia Level of anesthesia depends on: Position during and immediately after injection Cerebrospinal fluid measure Site and rate of injection Volume, dosage, specific gravity of solution Inclusion of vasoconstrictor will prolong effects Spinal curvature Interspace chosen Coughing and straining

Regional Anesthesia Epidural Agent is injected into the space between the ligamenta flava and the dura. Anesthesia is prolonged while drug is absorbed from CSF into the blood stream.

Regional Anesthesia Peripheral Block Bier Block or Intravenous Regional Block Document: Tourniquet application Pressure setting Inflation time Deflation time Surgeon should be notified of tourniquet time every 30 min. Deflation done intermittent to avoid toxic blood level and seizures.

Regional Anesthesia Monitored Anesthesia Care Physician administers local anesthesia Anesthesia personnel monitor pt If nursing personnel monitor pt, must be RN other than circulating nurse. Abnormalities reported to surgeon. Documentation: 1.monitoring of medications and their dose, route, time of administration, effects 2.pt’s LOC should be monitored and recorded.