Surg 102 Chapter 24 (B&K)--Part 2 Flashcards
Apply pressure to the _____ to occlude the esophagus and immobilize the trachea.
cricoid cartilage
Applying pressure to the cricoid cartilage is also called the _____.
Sellick’s maneuver
The Sellick’s maneuver prevents _____ and _____ of stomach contents.
regurgitation and aspiration
Compression of the cricoid cartilage must continue until the _____ is inflated and the anesthesia provider states that it is safe to release pressure.
endotracheal tube cuff
An _____ is performed before the induction of general anesthesia.
awake intubation
What are the most common indications for awake intubation?
acromegaly, anterior larynx, an enlarged tongue, a limited oral cavity, jaw fixation, a short neck, and limited cervical range of motion
The conditions that lead to an awake intubation may inhibit visualization of the vocal cords by direct laryngoscopy and thus increase the potential risk of _____.
airway obstruction
Awake intubation can be performed with a _____ or _____ for direct visualization of vocal cords.
fiberoptic or rigid laryngoscope
What are the five objectives of general anesthesia?
- oxygenation
- unconsciousness
- analgesia
- muscle relaxation
- control of autonomic reflexes
Oxygenation (as an objective of general anesthesia):
tissues, especially the brain, must be continuously perfused with oxygenated blood
Unconsciousness (as an objective of general anesthesia):
the patient remains asleep and unaware of the environment during the surgical procedure
Analgesia (as an objective of general anesthesia):
the patient must be free of pain during the surgical procedure
Muscle relaxation (as an objective of general anesthesia):
must be constantly assessed to provide necessary amounts of drugs that cause skeletal muscles to relax
Control of autonomic reflexes (as an objective of general anesthesia):
anesthetic agents affect cardiovascular and respiratory systems; tissue manipulations and systemic reactions to them may be altered by drugs that control the autonomic nervous system
All anesthesia machines have the following features:
- sources of oxygen and compressed gases
- means for measuring (flowmeters) and controlling (reservoir bag) delivery of gases
- means to volatilize liquid (vaporizer) and deliver (breathing tubes) anesthetic vapor or gas
- device for disposal of carbon dioxide
- safety devices
Safety devices on an anesthesia machine include the following:
- oxygen analyzers
- oxygen pressure interlock system (to shut off the flow)
- end-tidal carbon dioxide monitor
- pressure and disconnect alarms
- gas scavenger system
The method for administration of inhalation anesthetics through the anesthesia machine can be classified as _____, _____, _____, or _____.
semi-closed, closed, semi-open, or open
As it pertains to administration of inhalation anesthesia, describe a semi-closed system.
- most widely used
- permits exhaled gases to pass into the atmosphere so that they will not mix with fresh gasses and be re-breathed
- induction is slower but with less loss of heat ans water vapor that with open methods
As it pertains to administration of inhalation anesthesia, describe a closed system.
- allows complete re-breathing of expired gas
- exhaled CO2 is absorbed by soda lime or a mixture of barium and calcium hydroxide (Baralyme) in the absorber of the machine
- provides maximal conservation of heat
- reduces the amount and therefore cost of agents
- reduces environmental contamination
As it pertains to administration of inhalation anesthesia, describe a semi-open system.
- some exhaled gas can pass into surrounding air but some returns to the inspiratory part of the circuit for re-breathing
- degree of re-breathing is determined by the volume of flow of fresh gas
As it pertains to administration of inhalation anesthesia, describe an open system.
- valves direct expired gases into the lower portion of the canister, where they are removed by vacuum
- patient inhales only the anesthetic mixture delivered by the anesthesia machine
Anesthetic gas or vapor of a volatile liquid is inhaled through a _____ attached to the anesthesia machine by breathing tubes.
face mask
An airway can be maintained by inserting a _____ into the larynx.
laryngeal mask airway (LMA)
A laryngeal mask airway is a flexible tube that has an _____ silicone ring and cuff.
inflatable
When the cuff of the laryngeal mask airway (LMA) is inflated, the mask fills the space around and behind the _____ to form a seal between the tube and the _____.
larynx
trachea
Advantages of endotracheal administration of anesthetic vapor or gas are:
- ensures a patent airway and control of respiration
- secretions are easily removed from the trachea by suctioning
- protects the lungs from aspiration of blood, vomitus of gastric contents, or foreign material
- preserves the airway regardless of the patient’s position during the surgical procedure
- interferes minimally with the surgical fields during head and neck procedures
- helps minimize the escape of vapors or gases into the room atmosphere
Potential complications of endotracheal administration of anesthetic vapor or gas are:
- trauma to teeth, pharynx, vocal cords, or trachea
- cardiac dysrhythmias
- hypoxia and hypoxemia
- accidental esophageal or endobronchial intubation
- aspiration of gastrointestinal contents
Controlled respirations can be defined as the _____.
completely controlled rate and volume of respirations
Assisted respiration implies that the patient’s own _____ effort initiates the cycle.
respiratory
When is controlled aspiration is initiated?
after the anesthesia provider has produced apnea by hyperventilation or administration of respiratory depressant drugs or a neuromuscular blocker
Advantages or controlled respiration are:
- provides for optimal ventilation
- allows for selective lung deflation for thoracic procedures
- provides access to deep regions of the thorax and upper abdomen
- permits deliberate production of apnea to facilitate surgical manipulation below the diaphragm, ligation of deep vessels, or obtaining radiographic films
Nitrous oxide (N20)–Inhalation agent
Advantages
1. nonvolatile
2. rapid induction
3. pleasant, fruit-like odor
4. incidence of nausea and vomiting minimal
Disadvantages
1. can cause bowel distension and increased volume in other air pockets
2. can cause displacement of tympanoplasty grafts or increased intercranial pressure
Halothane (Fluothane)–Inhalation agent
Advantages 1. rapid with smooth induction Disadvantages 1. potentially toxic to the liver 2. has profound effect on body temperature control (may cause hypothermia)
Enflurane (Ethrane)–Inhalation agent
halogenated ether
Advantages
1. rapid induction and recovery with minimal aftereffects
Isoflurane (Forane)–Inhalation agent
- most commonly used
- nonflammable
- more potent muscle relaxant
- protects the heart against catecholamine-induced dysrhythmias
Desflurane (Suprane)–Inhalation agent
-nonflammable,volatile liquid Advantages --rapid emergence and recovery Disadvantages 1. pungent odor 2. may lower blood pressure 3. elevated heart rate
Sevoflurane (Ultane)–Inhalation agent
-volatile liquid, nonflammable Advantages --rapidly eliminated by lungs Disadvantages --may cause glycosuria
Thiopental (Pentothal)–intravenous agent
Advantages
- -onset of action within 30 seconds
- -short acting duration is 5 to 30 minutes depending on body mass
- -can be used as anticonvulsant
Propofol (Diprivan)–intravenous agent
-used for rapid induction
-can be used in combination with inhalation agents or opioids for prolonged anesthesia
Advantages
–rapidly distributed, metabolized, and eliminated
–emergence is very rapid, with few postoperative side effects
–can be used for postoperative nausea and vomiting
Disadvantages
–produces dose-related cardio-respiratory depression
–decreases blood pressure
Ketamine (Ketalar, Ketaject)–intravenous agent
Advantages
–rapid induction
–respirations not depressed unless drug is administered too rapidly or in too large a dose
Disadvantages
–psychological manifestations (delirium, vivid imagery, hallucinations, unpleasant dreams) may occur during emergence; these can be reduced by giving preanesthetic diazepam and allowing patient to lie quietly and undisturbed
Natural opiates and synthetic opioids have been given to produce _____ and _____ preoperatively and postoperatively.
analgesia and sedation
Narcotics are used in combination with _____ for complete anesthesia for short procedures.
oxygen
The most popular narcotics for general anesthesia are the opioids…
- fentanyl (Sublimaze)
- sufentanil (Sufenta)
- altentanil (Alfenta)
- meperidine (Demerol)
- morphine sulfate (opiate)
Narcotics may be given in _____ or _____ via IV infusion.
bolus or continuous
Narcotics produce a dose-related _____.
respiratory depression
The respiratory effects of narcotics are:
- reduction of responsiveness of CNS respiratory centers to CO2
- impairment of respiratory reflexes and alteration of rythmicity (prolonged aspiration, delayed expiration)
- reduction in the respiratory rate before reduction in the tidal volume
- production of bronchoconstriction or rigidity of chest wall
- impairment of ciliary motion
Factors that influence narcotic respiratory actions include:
- age
- pain
- sleep
- urinary output
- other drugs
- intestinal resorption
- disease
A narcotic _____ neutralizes or impedes the action of another drug.
antagonist (reversal)
What are two narcotic antagonists?
- Naloxone (Narcan)
2. Flumazenil (Romazicon)
What facilitates muscle relaxation for smoother endotracheal intubation and working conditions during the medical procedure?
neuromuscular blockers (muscle relaxers)
Neuromuscular blockers are administered via IV in small amounts at intervals, they interfere with the passage of impulses from _____ to _____.
motor nerves to skeletal muscles
Neuromuscular blockers _____ all skeletal muscles including the _____ and accessory muscles of respiration
paralyze
diaphragm
Mivacurium (mivacron)–short-acting neuromuscular blocking agent
-lasts 15-20 minutes
Atracurium (Tracrium)–intermediate-acting neuromuscular blocking agent
- lasts about 30 min
- metabolizes more quickly that other blockers (may be an advantage in patients with liver or renal disease)
Cisatracurium (Nimbex)–intermediate-acting neuromuscular blocking agent
-can cause bradycardia, hypotension, and skin flushing
(**)Rocuronium (Zemuron)–intermediate-acting neuromuscular blocking agent
- rapid onset
- lasts about 30 min
- can be reversed with neostigmine (**)
Tobocurarine (Curare)–long-acting neuromuscular blocking agent
-used as pretreatment is succinylcholine is used
Gallamine (Flaxedil)–long-acting neuromuscular blocking agent
-contraindicated in patients with iodine and sulfide allergies
Metocurine (Metubine)–long-acting neuromuscular blocking agent
-produces less hypotension
Pancuronium (Pavulon)–long-acting neuromuscular blocking agent
-has a vagolytic action that may raise the blood pressure, pulse rate, and heart rate
Pipecuronium (Arduan)–long-acting neuromuscular blocking agent
-can cause decreased arterial pressure with moderate histamine release
What are depolarizing neuromuscular blockers?
they stimulate autonomic receptors; they cause muscular fasciculation (involuntary muscle contractions)
Succinylcholine (Anectine)
- onset of action in seconds
- produces paralysis for up to 20 minutes
Decamethonium (Syncurine)
- rapid onest
- short duration
- used for deep relaxation of a short duration, such as endoscopy
Neostigmine (Prostigmin)–muscle relaxant reversal agent
- used to reverse nondepolarizing neuromuscular blocking agents
- not for use in patients with peritonitis or bowel or urinary obstruction
Edophonium (Tensilon)–muscle relaxant reversal agent
-rapid onset but short duration
The _____ monitors the level of anesthesia, balancing doses of medications, throughout the surgical procedure.
anesthesia provider
The _____ is a compact system for monitoring the effects of anesthesia on the brain.
Bispectral Index (BIS)
The BIS monitor allows the anesthesia provider to accurately track the patient’s level of _____ by using an electrode applied to the patient’s forehead that sends _____-like signals to a small monitor.
consciousness
eletroencephalogram (EEG)
The anesthesia provider attempts to have the patient _____ at the end of a surgical procedure.
as nearly awake as possible
Pharyngeal and laryngeal reflexes must be recovered to prevent _____ and _____.
aspiration and respiratory obstruction
Extubation is delayed until _____ is ensured.
spontaneous respiration
When extubation is deemed safe, the _____ is carefully removed.
endotracheal tube
Patient _____ and _____ may accompany emergence.
vomiting and restlessness
Slight cyanosis, stertorous respiration, rigidity, and shivering are not uncommon as a result of a _____, thus altering circulation to the skin and muscles.
temporary disturbance of body temperature-regulating mechanisms
Balanced anesthesia is a technique used to achieve _____.
physiologic homeostasis, analgesia, amnesia, and muscle relaxation
A _____ permits control of ventilation while providing muscle relaxation during intubation.
neuromuscular blockers
A _____ reduces motor activity and anxiety.
neuroleptic
Residual effects of narcotics or muscle relaxants my require _____ by antagonists during and/or at the conclusion of the surgical procedure.
reversal
Functions controlled by homeostatic mechanisms include:
- body temperature
- heartbeat
- blood pressure
- electrolyte balance
- respiration
The parameters of homeostasis may be altered by _____ and other _____ agents.
anesthetic
pharmacologic
_____ is an artificial, deliberate lowering of body temperature below the normal limits.
induced hypothermia
_____ reduces the metabolic rate and oxygen needs of the tissues in conditions causing hypoxia or during a decrease or interruption of circulation.
hypothermia
