overview of anesthesia. the four stages of anesthesia stage i: relaxation biologic response:...

Overview of Overview of AnesthesiaAnesthesia

The Four Stages of The Four Stages of AnesthesiaAnesthesia

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.


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.


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.


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 AgentsCommon 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.


Forane:

Disadvantage: • Pungent odor• Produces more coughing• expensive


Halothane:

Advantage: • Rarely irritates the brynx• Does not increase respiratory secretions


Halothane:

Disadvantage: • Cases of hepatitis have been reported

after administration• Should not be administered to patients

with abnormal liver fx.


Ethrane:

Advantage: • Rapid induction• Rapid recovery with minimal after effects


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.


Desflurane:

Advantage: • Allows much faster induction and

emergence• Offers good cardiovascular stability


Desflurane:

Disadvantage: • Strong odor


N2O • Inorganic gas of slight potency,• supports combustions when

combined with oxygen. • Only gas still in use for

anesthesia


N2O Advantage: rapid uptake and elimination


N2O Disadvantage: • no muscle relaxation, • possible excitement or

laryngospasm, • hypoxia a hazard


N2O Use: because it lacks potency, N2O is

rarely used alone, but as an adjunct to barbiturates, narcotics, and other drugs.

Intravenous Anesthetic Intravenous Anesthetic AgentsAgents

Because removal of drug from

circulation is impossible, safety in use is related to

metabolism.


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.


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.


High Dose Narcotics:

Following high dose narcotic anesthesia patients are:– awake, – pain free, – with adequate, though not good

ventilation


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.


High Dose Narcotics:Clinical signs of narcotic toxicity:• Pinpoint pupils• Depressed respirations• Reduced consciousness


High Dose Narcotics:Narcotic antagonist given to reverse

narcotic-induced hypoventilation.

Narcan


Nondepolarizing Neuromuscular blockers:

Act on enzymes to prevent muscle contraction.


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 AnesthesiaRegional Anesthesia

Spinal AnesthesiaAgent is injected into the cerebrospinal fluid

(CSF) in the subarachnoid space using a lumbar interspace in the vertebral column.


Spinal AnesthesiaLevel 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


EpiduralAgent 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.


Peripheral BlockBier 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.


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.

overview of anesthesia. the four stages of anesthesia stage i: relaxation biologic response:...

Documents

common inhalation agentsforane

stages of anesthesiastage

struggle pt

good muscle relaxation

dangerbiologic response

excitementbiologic response

relaxationbiologic response

analgesiapt reaction