Chapter 15: Sedatives, Analgesics, And Paralytics

Front 1

What effects do sedatives have on the body?

Back 1

1. Sedatives reduce anxiety and agitation and promote sleep and anterograde amnesia.

Front 2

Why is paralysis used during mechanical ventilation?

Back 2

2. Paralysis is used to facilitate invasive procedures, such as intubation, to ensure the stability of an airway and to decrease mean airway pressure during uncoordinated or uncontrolled mechanical ventilation.

Front 3

List the four types of pharmacological agents used for sedation in the ICU. Give at least one example of each.

Back 3

3. (a) Benzodiazepines (diazepam, midazolam, and lorazepam), (b) opioids (morphine, fentanyl), neuroleptics (haloperidol), (c) anesthetic agents (propofol), and (d) opioids (morphine, fentanyl).

Front 4

What modes of ventilation often require patients to be sedated?

Back 4

3. (a) Benzodiazepines (diazepam, midazolam, and lorazepam), (b) opioids (morphine, fentanyl), neuroleptics (haloperidol), (c) anesthetic agents (propofol), and (d) opioids (morphine, fentanyl).

Front 5

Name the four JCAHO-defined levels of sedation.

Back 5

3. (a) Benzodiazepines (diazepam, midazolam, and lorazepam), (b) opioids (morphine, fentanyl), neuroleptics (haloperidol), (c) anesthetic agents (propofol), and (d) opioids (morphine, fentanyl).

Front 6

Complete the following table using the four JCAHO-defined levels of sedation. What type of patient response and ventilatory and cardiovascular function do patients have at each level of sedation?

Back 6

6.

Sedation Level
Patient Response Ventilatory Function Cardiovascular Function
Minimal Positive to verbal commands; cognitive function may be impaired Unaffected Unaffected
Moderate Positive to verbal commands; may require tactile stimulation Maintained Maintained
Deep Not easily aroused; positive to painful stimuli Inadequate spontaneous ventilation and patent airway Maintained
Anesthesia Cannot be aroused even with painful stimuli Requires ventilatory assistance with artificial airway and PPV May be impaired

Front 7

What level of sedation may be necessary when a patient's breathing is asynchronous with the mechanical ventilatory mode?

Back 7

7. Deep sedation may be required during the initial phases of mechanical ventilation, especially when the patient is asynchronous.

Front 8

What level of sedation is necessary during weaning from mechanical ventilation?

Back 8

7. Deep sedation may be required during the initial phases of mechanical ventilation, especially when the patient is asynchronous.

Front 9

What scoring systems may be used to assess the level of sedation in adults and children?

Back 9

8. If sedation is necessary during weaning from mechanical ventilation, minimal levels of sedation should be used.

Front 10

What range of scores indicates adequate sedation?

Back 10

10. A score of 2 to 4 on the Ramsay scale indicates adequate sedation.

Front 11

What score indicates the need for sedation?

Back 11

11. A score of 1 indicates the need for sedation.

Front 12

What scores indicate oversedation of a patient?

Back 12

12. Scores of 5 to 6 indicate oversedation for a patient.

Front 13

Why are benzodiazepines the drugs of choice for the treatment of anxiety in critical care?

Back 13

13. Benzodiazepines are the drugs of choice for anxiety because of their ability to produce anxiolytic, hypnotic, muscle relaxing, anticonvulsant, and anterograde amnesic effects.

Front 14

What is the mode of action for benzodiazepines?

Back 14

14. Benzodiazepines depress the CNS by binding to receptors in the GABA receptor complex on neurons in the brain. This increases the chloride permeability of the neuron, which in turn hyperpolarizes the neuron, making it less likely to depolarize.

Front 15

What factors alter the intensity and duration of action of various benzodiazepines?

Back 15

15. Factors that influence the duration of action of benzodiazepines include age, underlying pathology, and concurrent drug therapy.

Front 16

What pathological processes prolong recovery from treatment with benzodiazepines?

Back 16

16. Hepatic and renal insufficiencies prolong the recovery from benzodiazepines.

Front 17

Why does diazepam have a rapid onset of action?

Back 17

17. Diazepam has a rapid onset of action because of its high lipid solubility and ability to traverse the blood-brain barrier relatively quickly. Onset is 3 to 5 minutes when the drug is administered IV.

Front 18

How is diazepam administered?

Back 18

18. IV bolus at the start of infusion, followed by a series of smaller boluses with close titration to produce the desired plasma concentration of the drug

Front 19

Acutely agitated patients are best treated with which benzodiazepine? Why?

Back 19

19. Acutely agitated patients are best treated with midazolam (Versed), because it has a rapid onset and a short half-life.

Front 20

How can prolonged sedation occur with midazolam?

Back 20

20. Prolonged sedation with midazolam can occur from accumulation of the drug and its metabolites in the peripheral tissues when it is used for longer than 48 hours.

Front 21

Which benzodiazepine is best suited for sedating mechanically ventilated patients in the ICU for longer than 24 hours?

Back 21

21. Lorazepam (Ativan) is the drug of choice for use with ventilated patients for longer than 24 hours.

Front 22

An overdose of benzodiazepines may be reversed with what drug?

Back 22

22. Flumazenil (Romazicon) reverses the effects of benzodiazepines.

Front 23

Potential side effects of continual use of lorazepam (Ativan) include:

Back 23

23. Lactic acidosis, hyperosmolar coma, and a reversible nephrotoxicity.

Front 24

What class of drugs is routinely used to treat extremely agitated and delirious patients in the ICU?

Back 24

24. neuroleptics

Front 25

The drug most often used to treat ICU delirium is

Back 25

25. haloperidol

Front 26

What are some of the side effects of the drug haloperidol?

Back 26

26. Haloperidol has antidopaminergic and anticholinergic effects. It can induce alpha blockade, lower the seizure threshold, and evoke Parkinson-like symptoms (i.e., extrapyramidal effects, such as muscle rigidity, drowsiness, and lethargy). Dose-dependent cardiac dysrhythmias, including QT prolongation and torsades de pointes, have also been reported, particularly in patients receiving high-dose bolus IV administration of haloperidol.

Front 27

The anesthetic agent that has proved useful for sedation of neurosurgical patients is

Back 27

27. propofol (Diprivan)

Front 28

What are the hemodynamic effects of the drug propofol

Back 28

28. Propofol (Diprivan) causes a reduction in systemic vascular resistance with a concomitant fall in blood pressure and bradycardia during the initial induction phase; it also reduces cerebral blood flow and ICP.

Front 29

What are the advantages and disadvantages of using haloperidol and propofol to sedate neurological patients.

Back 29

29.
Advantages Disadvantages
Rapid onset, short duration of action (makes rapid awakening possible for neurological assessment), decreased ICP, clearance unaffected by renal or hepatic dysfunction. Hypotension, dysrhythmias, bradycardia, and elevated pancreatic enzymes. Prolonged use has been associated with lactic acidosis and lipidemia in pediatric patients.

Front 30

Name the two most commonly used opioids:

Back 30

30. (a) morphine and (b) fentanyl

Front 31

List three effects that opiates have on the body.

Back 31

31. (a) Relieve pain, (b) sedate, and (c) relieve anxiety.

Front 32

How do opiates exert their effects on the body?

Back 32

32. Their effects are mediated through μ and κ receptors. μ Receptors are responsible for analgesia, and κ receptors mediate the sedative effects.

Front 33

List at least ten side effects of opioids.

Back 33

33. Side effects of opioids include (any of the following) nausea, vomiting, reduced gastrointestinal motility, respiratory depression, bradycardia, hypotension, myoclonus, convulsions, histamine release, immunosuppression, and addiction.

Front 34

What determines the severity of the side effects of opioids?

Back 34

34. The severity of these side effects depends on the dosage administered, the extent of the patient`s illness, and the integrity of organ function (i.e., renal, hepatic, and hemodynamic function).

Front 35

Which drug can reverse the respiratory depression caused by opioids?

Back 35

35. naloxone hydrochloride (Narcan)

Front 36

What effects does morphine have on the central nervous system?

Back 36

36. Morphine`s effects on the CNS also include reduction of cerebral blood flow, intracranial pressure, and cerebral metabolic activity; drowsiness and lethargy; miosis; and suppression of the cough reflex.

Front 37

How does morphine affect the gastrointestinal tract?

Back 37

37. Reduction of lower esophageal sphincter tone and propulsive peristaltic activity of the intestine, which in turn leads to constipation. Morphine can increase the tone of the pyloric sphincter and ultimately lead to nausea and vomiting by delaying the passage of contents through the GI tract.

Front 38

How does morphine affect the cardiovascular system?

Back 38

38. Morphine can alter vascular resistance by causing a decrease in sympathetic tone and an increase in vagal tone. Reduction in vascular tone can lead to significant hypotension in patients who rely on increased sympathetic tone to maintain blood pressure.

Front 39

Which opioid should be used for a patient whose hemodynamic status is unstable?

Back 39

39. Fentanyl has minimal effects on the cardiovascular system and therefore should be used for patients with an unstable hemodynamic status.
40.

Front 40

Increased intracranial pressure caused by traumatic brain injury may be controlled by a combination of which two drugs?

Back 40

41. Morphine and propofol

Front 41

What type of drug is used to reduce oxygen consumption and carbon dioxide production?

Back 41

42. NMBAs

Front 42

What is the difference between depolarizing and nondepolarizing agents?

Back 42

43. Depolarizing NMBAs bind to acetylcholine receptors, causing prolonged depolarization of the motor end plate. Nondepolarizing NMBAs cause paralysis by competitively inhibiting the action of acetylcholine at the neuromuscular junction.

Front 43

Why are NMBAs used while a patient is being mechanically ventilated?

Back 43

44. NMBAs are used (1) when patient-ventilator dyssynchrony cannot be corrected by adjusting ventilator settings; (2) to facilitate less conventional mechanical ventilation strategies (e.g., inverse I:E ratios, high-frequency ventilation, permissive hypercapnia); (3) when dynamic hyperinflation cannot be corrected; and (4) to reduce oxygen consumption and carbon dioxide production.

Front 44

What is the pupose of train-of-four monitoring (TOF)?

Back 44

45. To assess a patient’s depth of paralysis.

Front 45

How does TOF operate?

Back 45

46. Two electrodes are placed on the skin along a nerve path, near a hand, foot, or facial nerve. An electrical current consisting of four impulses is applied to the peripheral nerve over 2 seconds; the muscle contractions (twitches) produced provide information about the level of paralysis.

Front 46

According to the Society for Critical Care Medicine, what indicates that an adequate amount of NMBA is being administered when TOF is used?

Back 46

47. One or two twitches when the train-of-four test is performed indicate that an adequate amount of NMBA is being used.

Front 47

What other medication is necessary when a paralytic agent is used?

Back 47

48. Patients receiving an NMBA must also be given sedation, because NMBAs do not sedate the individual.

Front 48

What other medication is necessary when a paralytic agent is used?

Back 48

. Patients receiving an NMBA must also be given sedation, because NMBAs do not sedate the individual.

Front 49

The most widely used depolarizing NMBA is:

Back 49

. succinylcholine (Anectine)

Front 50

What are the onset of action and duration of action for the drug referred to in succinylcholine.

Back 50

. Succinylcholine’s onset is approximately 1 minute, and its duration of action is 5 to 10 minutes.

Front 51

For what purpose is the drug referred to in succinylcholine used?

Back 51

. Succinylcholine is used most often to facilitate endotracheal intubation.
52.

Front 52

Which nonelpolarizing NMBAs are used for intermediate duration?

Back 52

. Vecuronium bromide (Norcuron), atracurium besylate (Tracrium), and cisatracurium besylate (Nimbex) are intermediate-duration, nondepolarizing NMBAs.

Front 53

What type of patient could experience prolonged paralysis after discontinuation of pancuronium? Why?

Back 53

. Prolonged paralysis after discontinuation of pancuronium can occur in patients with renal and hepatic failure. The prolonged duration of action may be partially explained by the fact that it is metabolized in the liver to an active 3-hydroxy metabolite that retains up to 50% of the activity of the parent compound

Front 54

Seizures have been associated with which nondepolarizing NMBA?

Back 54

. Atracurium besylate (Tracrium)

Front 55

Mast cell degranulation and histamine release, which may lead to peripheral vasodilation and hypotension, are associated with which nondepolarizing NMBA?

Back 55

. Atracurium besylate (Tracrium)

Front 56

Which nondepolarizing NMBAs are ideal for patients with renal and hepatic insufficiency?

Back 56

. Atracurium besylate (Tracrium) and cisatracurium besylate (Nimbex)

Front 57

Which nondepolarizing NMBA of choice for patients who are hemodynamically unstable, have cardiac disease, or are at risk of histamine release is:

Back 57

. Cisatracurium besylate (Nimbex)

Front 58

Give two side effects of the long-term use of neuromuscular blocking agents.

Back 58

. (a) Tolerance, which may necessitate increasing the dosage, and (b) muscle weakness.

Front 59

When a neuromuscular blocking agent is administered to a patient receiving ventilatory care, what ventilator alarms should be activated?

Back 59

. When an NMBA is used in a mechanically ventilated patient, the apnea alarm, low inspiratory pressure alarm, low exhaled VT alarm, and low exhaled minute volume alarm should be set and active. If a pulse oximeter is used continually, the low SpO2 alarm should be used.

Front 60

Which type of opioid is best suited to a patient who has asthma? Why?

Back 60

Fentanyl (Sublimaze), a synthetic opioid, is the best choice for patients with asthma, because it does not cause histamine release, as morphine does. Morphine is not recommended in patients with asthma, because its mast cell–mediated histamine release may worsen bronchoconstriction.