Nursing College

1. Anesthesia and Medication
Safety 1
Dr. marwan

2. Overview
Little more than 100 years ago, anesthesia for surgical procedures was
limited to administration of ether.
Depth of anesthesia and physiologic response were inconsistent and poorly
controlled.
The risk of complication was high.
Before the 1970s, the death rate associated with complications from
anesthesia was approximately 357 per 1 million.
By the early 2000s, the rate had dropped to 34 per 1 million

3. Factors responsible for improving anesthesia
• Development of sophisticated anesthesia and airway management techniques
• Anesthetic agents
• Improved preanesthesia assessment
• Technologically advanced monitoring Devices
Although the death rate associated with anesthesia is extremely low,
the risk of complications related to compromised ventilation, perfusion, and cardiac
output, and altered hypothalamic thermoregulation persists.

4. Desired outcomes
- successful recovery
return to the preanesthesia physiologic state, including
normothermia, adequate ventilation, maintenance of cardiac output ,
electrolyte and fluid balance.
- absence of allergic reaction, or drug complications.

5. Preanesthesia assessment
The patient’s physical status is classified according
to the ASA’s classification system. (PS):
• PS 1: a normal healthy patient. Example: healthy, nonsmoking,
• PS 2: mild systemic disease. Example: current smoker, social alcohol drinker, pregnancy, well
controlled diabetes or hypertension, mild lung disease
• PS 3: severe systemic disease. Example: one or more moderate to severe diseases: poorly controlled
diabetes, hypertension, chronic obstructive pulmonary disease (COPD), morbid obesity (BMI ≥40),
active hepatitis, alcohol dependence or abuse
• PS 4: severe systemic disease that is a constant threat to life. Example: recent (within 3 months)
myocardial infarction (MI),ongoing cardiac ischemia or severe valve dysfunction, or end-stage renal
disease (ESRD) not undergoing regularly scheduled dialysis
• PS 5: moribund and not expected to survive without the operation. Example: ruptured
abdominal/thoracic aneurysm, massive trauma, intracranial bleed with mass effect.
PS 6: declared brain-dead patient whose organs are being removed for donor purposes

6. The ASA classification system is useful in determining the anesthesia
technique to be used.
For example:
• Some centers do not permit PS 3 patients to undergo surgery under
general anesthesia as an ambulatory surgery patient.
• PS 3 and higher patients must have an anesthesiologist, a CRNA, or
an AA present during surgery even when the anesthesia technique is
limited to moderate sedation/ analgesia.

7. Fasting befor anesthesia
• Clear liquids: 2 hours
• Human milk: 4 hours
• Infant formula: 6 hours
• Nonhuman milk: 6 hours
• Light meal: 6 hours
• Fatty foods: 8 hours

8. These guidelines do not apply to the following Patients.
• when no anesthesia or only local anesthesia
• Women in labor
• Patients with diseases or conditions affect gastric emptying (e.g.,
pregnancy, obesity, diabetes, hiatal hernia, bowel obstruction,
emergency care.)
• Patients in whom airway management might be difficult

9. Preparation/Premedication
Goals of preoperative medication may include one or more of the
following:
• Reduction of anxiety
• Sedation
• Analgesia
• Amnesia
• Prevention of nausea and vomiting
• Reduction in gastric volume and acidity
• Facilitation of induction
• Reduction of risk of allergic reaction
• Decrease of secretions
• Prevention of infection

10. Oral medications are usually given 60 to 90 minutes prior to surgery, IV agents 30
to 60 minutes prior to surgery.
Some agents—such as metoclopramide which is used to promote gastric emptying
and lower stomach pH—are given 15 to 30 minutes.
Conditions that suggest high risk for aspiration include the following:
• Morbid obesity
• Old age
• Pregnancy
• Hiatal hernia with reflux
• Uncertain NPO status coupled with the need for emergency surgery
• History of diabetes with gastroparesis
• History of partial bowel obstruction
• History of peptic ulcer disease

11. Anesthesia Techniques
Anesthesia may administered by general, regional, local, or moderate
sedation/conscious sedation techniques.
General anesthesia depresses the central nervous system.
The patient is unconscious and reflexes are obtunded.
The patient’s physiologic status is controlled by the anesthesia provider.
The effects of regional anesthesia are limited to a region of the body, such as a
limb or the lower half of the body.

12. Regional anesthesia can be divided into central and peripheral techniques:
• Central techniques include neuraxial blocks (epidural anesthesia, spinal
anesthesia).
• Peripheral techniques include plexus blocks (e.g., brachial plexus blocks) and
single
nerve blocks.
Regional anesthesia may be administered as a single injection or by inserting a
catheter through which medication is administered over a prolonged period (e.g.,
epidural, continuous peripheral nerve block).
An intravenous regional block (Bier block) involves isolating the vasculature of a limb
with a double tourniquet and injecting a local anesthetic such as lidocaine into the
vein.
The patient is awake but does not feel pain over the anesthetized region.
Additional medications may be administered to reduce anxiety and provide sedation.

13. Local anesthesia is actually a form of regional anesthesia; however,
only a small, localized area is infiltrated using an anesthetic such as
lidocaine or bupivacaine .
This infiltration is often performed by the surgeon on the field rather than
by the anesthesia provider.

14. General Anesthesia
Effects of general anesthesia include
Amnesia (loss of memory),
Hypnosis (loss of consciousness),
Analgesia (absence of the sense of pain),
and skeletal muscle Relaxation.
General anesthesia is delivered with inhalation agents and
intravenous medications.

15. The initial practice of anesthesiology used single drugs such as ether or chloroform to
abolish consciousness, prevent movement during surgery, ensure amnesia, and
provide analgesia.
current anesthesia practice combines multiple agents, to achieve specific end points.
Inhalational agents remain the core of modern anesthetic combinations, most
anesthesiologists initiate anesthesia with intravenous (IV) induction agents and
maintain anesthesia with inhalational agents supplemented by IV opioids and muscle
relaxants.
Benzodiazepines are often added to induce anxiolysis and amnesia.
In many cases, total intravenous anesthesia (TIVA) is desirable such as propofol in
combination with opioids and other adjuncts.

16. Inhalational Agents
The original inhalational anesthetics—ether, nitrous oxide, and chloroform—had
important limitations.
Ether ….. Has slow induction and delayed emergence but produce
unconsciousness, amnesia, analgesia, and lack of movement without the addition
of other agents.
In contrast, induction and emergence were rapid with nitrous oxide, but the agent
lacked sufficient potency to be used alone.
Nevertheless,
nitrous oxide is still used in combination with other agents in modern practice.
Chloroform … hepatic toxicity and occasionally fatal cardiac arrhythmias.

17. New inhalational agents
facilitate rapid induction and emergence and are nontoxic;
These agents include isoflurane, sevoflurane, and desflurane.
Although halothane also commonly used in the past, the use of this
agent has decreased more recently.
Inhalation agents, can be easily removed from the body by ventilating
the lungs

18. Intravenous Agents
Since the introduction of thiopental, IV agents have become a component of
modern anesthetic practice.
IV agents are used primarily for induction of anesthesia and as part of a multidrug
combination to produce TIVA.
most intravenous agents must be metabolized by the liver or kidneys to be
eliminated from the body
Induction Agents
Most adult patients and many older children prefer IV induction.
IV induction is rapid, pleasant, and safe for most patients,
propofol is the most widely used agent.

19. Important IV agents
Barbiturates introduced in 1935 with thiopental sodium.
short-acting agents that result in a rapid progression from sedation
to loss of consciousness.
Barbiturates do not provide analgesia.
They are also potent respiratory depressants; induction followed by
transient apnea, which requires oxygen to support the patient’s
ventilation.

20. The nonbarbiturate drug
propofol
a hypnotic-sedative agent, the most popular medication for producing a rapid
induction.
Propofol is also used for sedation for short procedures such as colonoscopy,
esophagogastroduodenoscopy (EGD), and pain therapies.
Propofol is delivered in a milky-white, emulsion.
support microbial growth; therefore, handling of propofol requires strict aseptic
technique.
Administration should be completed within 6 hours after opening .
After 6 hours, the product should be discarded, and the lines should be flushed or
discarded

21. propofol is a potent vein irritant can cause pain.
Discomfort can be reduced by prior injection of 1–2 mL of lidocaine, or 20 mg of
lidocaine can be mixed in 200 mg propofol .
Recovery from propofol is more rabid than barbiturates.
This drug has fewer incidences of postoperative nausea and vomiting.
It is often used in ambulatory surgery settings.
Etomidate
is a nonbarbiturate induction agent .
has minimal effects on myocardial function, cardiac output, and peripheral or
pulmonary circulation.
It is a short-acting agent and is generally utilized for patients with a positive cardiac
history and patients who cannot tolerate dramatic changes in blood pressure.

22. Ketamine is rapidly metabolized, and patients emerge quickly from its effects.
Ketamine may be given either intravenously (IV) or intramuscularly (IM).
Ketamine is useful for diagnostic procedures and procedures where it is desirable to have the patient
breathe unassisted.
sometimes used for children who undergo short procedures that do not require muscle relaxation.
produces a dramatic increase in oral secretions.
Because ketamine is a dissociative agent, patients may experience hallucinations postoperatively.
This after effect is more common in adults and may be minimized when diazepam or midazolam is
given.
The patient should recover in a quiet, darkened area.

23. Narcotics
* used preoperatively as a premedication or intraoperatively during induction .
* Include fentanyl , sufentanil, morphine, hydromorphone .
* Fentanyl is 100 times more potent than morphine, and sufentanil is 5–10 times. more potent than
fentanyl.
* Small doses used intraoperatively as adjuncts to other drugs and to provide pain relief in the early
postoperative Period.
* Narcotics provide profound analgesia and can be particularly valuable in cardiac surgery, because
sternotomy is especially painful/ stimulating.
* Narcotics are respiratory depressants, and patients who have received high doses of narcotics
intraoperatively must be monitored closely to ensure that they are breathing adequately.
* A patient who has received a high dose of narcotic intraoperatively may appear
to be awake and alert postoperatively but may suddenly begin to hypoventilate and lose
consciousness.

24. Naloxone
is an opiate antagonist binds to the opioid receptors.
If the patient is apneic, it is recommended that 0.4 mg or 1 ampule of naloxone
be administered IV or IM with careful monitoring.
If the patient is not apneic but has a falling O2 saturation, it is recommended
that naloxone be titrated into effect.

25. Tranquilizers/Benzodiazepines
Tranquilizers used for induction and as adjuncts to other anesthetic agents;
lower doses of other agents can be administered.
Tranquilizers used intraoperatively include diazepam and midazolam.
Diazepam produces amnesia and reduces anxiety.
Midazolam is an excellent amnestic and also provides significant anxiolysis.
Flumazenil is used to reverse the effects of benzodiazepines.
It reverses sedation and respiratory depression without producing cardiovascular
effects.
flumazenil may lose its effect sooner than the underlying benzodiazepine, and
hypoventilation can recur so require close observation .

26. Neuromuscular Blockers (Muscle Relaxants)
Muscle relaxants commonly used intraoperatively include succinylcholine
cisatracurium and vecuronium bromide.
The two primary indications for neuromuscular blockers are:
• To relax the jaw and larynx to facilitate controlled breathing and tracheal
intubation
• To increase muscle relaxation to permit ease of tissue handling during surgery
Muscle relaxants vary in their onset and duration.
Neuromuscular blockers paralyze the neuromuscular junction and block impulses
from motor nerves to skeletal muscle. The patient becomes paralyzed.

27. Anesthesia Machine
Today’s anesthesia machines provide accurate concentrations of volatile anesthetic agents and
oxygen, provide mechanical ventilator, suction,
and monitoring for blood pressure, ECG, inspired oxygen, and carbon dioxide.
The vaporizer transforms volatile anesthetic agents from liquid into gas for delivery to the patient.
The anesthesia provider selects the ratio of gases to deliver to the patient.
Expired gases from the patient pass through an absorber that removes the carbon dioxide.
The machine has a shutoff device that prevents nitrous oxide from being delivered if oxygen is not
also delivered at a concentration of at least 21%.
There is an oxygen flush valve that delivers 100% oxygen to the patient.
The machine has an alarm system that indicates when the patient has apnea or the breathing circuit
has become detached from the machine.