Mechanical ventilation is a medical intervention for critically ill patients who are unable to breathe on their own. While the machine itself provides ventilatory support, the use of drugs in conjunction with mechanical ventilation can greatly improve the patient’s comfort and outcome.
Some examples include sedatives, analgesics, and paralytics, each serving a unique purpose.
In this article, we will explore the different drugs used in mechanical ventilation, their mechanisms of action, and their potential side effects.
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Type of Drugs Used in Mechanical Ventilation
Drug therapy during mechanical ventilation is necessary to facilitate airway management and provide patient comfort. Some examples of the most common types include:
The use of drug therapy during mechanical ventilation is essential to achieve a desired patient outcome.
That is why respiratory therapists must fully understand these drugs to avoid complications and prolonged mechanical ventilation.
Sedatives are a class of drugs used to calm and relax the patient, reduce anxiety, and maintain the patient-ventilator interaction. The most commonly used sedatives during mechanical ventilation include:
- Benzodiazepines (e.g., diazepam, midazolam, and lorazepam)
- Neuroleptics (e.g., haloperidol)
- Anesthetic agents (e.g., propofol)
Benzodiazepines are used to treat anxiety in the intensive care unit (ICU). They work by enhancing the effects of the neurotransmitter GABA in the brain, producing a calming effect.
The types of benzodiazepines used in mechanical ventilation include:
- Diazepam (Valium)
- Midazolam (Versed)
- Lorazepam (Ativan)
Midazolam and diazepam are used for rapid sedation for mechanical ventilation in acutely agitated patients.
Lorazepam has a slower onset of action and is used for longer-acting sedation (i.e., more than 24 hours).
Neuroleptics are used during mechanical ventilation to treat patients with agitation and delirium.
An example includes haloperidol, which is a butyrophenone that works by promoting CNS depression. The drug has an onset of 3–20 minutes after a 5 mg dose is administered via IV.
Anesthetic agents are drugs used to induce and maintain general anesthesia, a state of unconsciousness and insensitivity to pain. An example includes Propofol (Diprivan), which is used to provide sedation during mechanical ventilation in critically ill patients.
Propofol has a rapid onset, but the duration of sedation only lasts for a short time once the drug is discontinued. This makes it the ideal choice for patients who require rapid awakening.
Note: Anesthetic agents do not have pain-relieving effects; therefore, they are typically used in conjunction with other drugs to provide adequate pain control.
Analgesic agents are a class of drugs used to relieve pain and prevent discomfort associated with mechanical ventilation. The most commonly used analgesic agents during mechanical ventilation include opioids, such as:
- Hydromorphone (Dilaudid)
Opioids are a class of narcotic drugs that are used to relieve pain, and they also have sedative and anxiolytic effects. The most common types that are used during mechanical ventilation include morphine and fentanyl.
Morphine has a slower onset of action, making it useful for longer-term pain management.
Fentanyl, on the other hand, is a more potent opioid with a rapid onset of action and a short duration of effect. It is often used in the ICU for short-term pain relief or as a supplement to other sedative drugs.
Hydromorphone (Dilaudid) is an opioid with a rapid onset of action and is an acceptable substitute for morphine.
Note: Opioids can cause potential side effects, such as nausea, vomiting, bradycardia, hypotension, convulsions, immunosuppression, physical dependence, and respiratory depression. A narcotic overdose can be treated and reversed with naloxone hydrochloride (Narcan).
Paralytic agents are a class of drugs used to help with intubation, provide muscle relaxation, relieve laryngeal spasm, and maintain mechanical ventilation.
Paralysis can be achieved with neuromuscular blocking agents (NMBA) that are classified as depolarizing and nondepolarizing, depending on their mode of action.
Depolarizing agents work by binding to acetylcholine receptors at the neuromuscular junction and directly stimulating the muscle fibers, causing them to contract.
This results in the complete paralysis of the muscle, which can be used to provide muscle relaxation during mechanical ventilation.
Succinylcholine chloride (Anectine) is the most commonly used depolarizing agent, which is a short-acting drug that provides rapid onset and short duration of action. It’s helpful in facilitating endotracheal intubation.
Given the availability of safer and more effective neuromuscular blocking agents, the use of depolarizing agents in mechanical ventilation is now limited, and they are only used in specific circumstances.
Nondepolarizing agents work by binding to acetylcholine receptors at the neuromuscular junction and blocking the transmission of nerve impulses to the muscles, resulting in paralysis and muscular relaxation.
These drugs are the most commonly used type of neuromuscular blocking agents and are considered to be safer and more effective than depolarizing agents.
The most common types of nondepolarizing agents include:
Pancuronium (Pavulon) has a relatively slow onset of action and a long duration of effect, making it useful for patients who need to be intubated for an extended period of time.
Vecuronium bromide (Norcuron) has a quicker onset of action and a shorter duration of effect, making it a popular choice for procedures that require rapid intubation.
Atracurium besylate (Tracrium) and cisatracurium besylate (Nimbex) are nondepolarizing muscle relaxants with an intermediate duration of effect. They’re advantageous in some cases because they do not have hemodynamic side effects.
Note: Neuromuscular blocking agents do not have sedative or analgesic effects. In other words, they do not reduce anxiety or provide pain relief. This means that they must be used in conjunction with sedatives and analgesic agents to ensure patient comfort.
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1. What are the three most common types of drugs used during ventilation?
Neuromuscular blocking agents, sedatives, and analgesics
2. What are some examples of neuromuscular blocking agents?
Succinylcholine chloride, vecuronium, pavulon, rocuronium, atracurium, and cisatracurium
3. What is the action of succinylcholine chloride?
It is an ultrashort-acting depolarizing agent.
4. What are some examples of drugs used for sedation and analgesia?
Lorazepam (Ativan), midazolam (Versed), morphine, Dilaudid, fentanyl, and propofol
5. What are metaproterenol (Alupent) and albuterol (Ventolin)?
They are short-acting bronchodilators used to reverse acute bronchospasm and are given in 15–30 minute intervals until effective.
6. What is Methylprednisone (Solu-Medrol)?
It is a corticosteroid used along with bronchodilators to decrease inflammation and acute respiratory failure.
7. What is dexmedetomidine (Precedex)?
It is a sedative, amnesic, and analgesic drug indicated for short-term sedation during mechanical ventilation. Its side effects include nausea, bradycardia, and hypotension.
8. What are opioids?
They are used to decrease pain in patients with acute respiratory failure who are on the mechanical ventilator. They are administered along with sedatives and paralytics.
9. What is acetylcholine?
It is an ester that plays a role in transmitting nerve impulses at synapses and neuromuscular junctions. It is metabolized by the enzyme cholinesterase. Too much or too little acetylcholine at the motor endplates may lead to muscle blockade.
10. What are barbiturates?
Barbiturates are a group of drugs that depress the central nervous system.
11. What are benzodiazepines?
Benzodiazepines are a group of drugs with strong hypnotic and sedative actions that are used to reduce anxiety and induce sleep.
12. What are depolarizing agents?
They are drugs that prolong the depolarization phase of muscle contraction, thus rendering the repolarization/depolarization sequence impossible, causing muscle blockade.
13. What is gamma-aminobutyric acid (GABA)?
A major central nervous system inhibitory transmitter that regulates the chloride ion channel and hyperpolarizes the neurons. Once the neurons are hyperpolarized and become resistant to repeated depolarization, sedation occurs.
14. What is haloperidol (Haldol)?
A drug used to control delirium in mechanically ventilated patients.
15. What are some examples of nondepolarizing agents?
Vecuronium bromide (Norcuron) and pancuronium bromide (Pavulon)
16. What is propofol (Diprivan)?
An intravenous drug that provides a spectrum of CNS effects ranging from light sedation to deep anesthesia.
17. What is the Ramsay Scale?
A scoring system with a scale ranging from level I to VI that is used to assess a patient’s degree of sedation.
18. What is the generic name of Xanax, and what type of drug is it?
19. What is the generic name of Valium, and what type of drug is it?
20. What is the generic name of Versed, and what type of drug is it?
21. What is the generic name of Ativan, and what type of drug is it?
22. What is a common brand name of Alprazolam, and what type of drug is it?
23. What is a common brand name of Diazepam, and what type of drug is it?
24. What is a common brand name of Midazolam, and what type of drug is it?
25. What is a common brand name of Lorazepam, and what type of drug is it?
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26. What are the four most common types of sedatives?
Alprazolam (Xanax), diazepam (Valium), midazolam (Versed), and lorazepam (Ativan)
27. What do sedative drugs do?
They help to decrease anxiety and promote relaxation.
28. What are the three most common types of anesthetic drugs?
Propofol (Diprivan), ketamine (Ketalar), and etomidate (Amidate)
29. What do anesthetic drugs do?
They decrease the patient’s ability to perceive sensation.
30. What is the generic name for Diprivan, and what type of drug is it?
31. What is the generic name for Ketalar, and what type of drug is it?
32. What is a generic name for Amidate, and what type of drug is it?
33. What are the most common types of analgesics?
Morphine, codeine, meperidine (Demerol), fentanyl, hydromorphone (Dilaudid), oxycodone (Oxycontin), and hydrocodone.
34. What is the generic name for Demerol, and what type of drug is it?
35. What is the generic name for Sublimaze, and what type of drug is it?
36. What is the generic name for Dilaudid, and what type of drug is it?
37. What is the generic name for Oxycontin, and what type of drug is it?
38. What is a brand name for Meperidine, and what type of drug is it?
39. What is a brand name for Fentalyn, and what type of drug is it?
40. What is a brand name for Hydromorphone, and what type of drug is it?
41. What is a brand name for Oxycodone, and what type of drug is it?
42. What do analgesic drugs do?
They help to decrease the sensation of pain without the loss of consciousness.
43. What are the most common neuromuscular blocking sgents?
Pancuronium (Pavulon), vecuronium (Norcuron), rocuronium (Zemuron), cisatracurium (Nimbex), atracurium (Tracrium), and auccinylcholine (Anectine)
44. What is a generic name of Pavulon, and what type of drug is it?
Pancuronium; neuromuscular blocking agent.
45. What is a generic name of Norcuron, and what type of drug is it?
Vecuronium; neuromuscular blocking agent.
46. What is a generic name of Zemuron, and what type of drug is it?
Rocuronium; neuromuscular blocking agent.
47. What is a generic name of Nimbex, and what type of drug is it?
Cisatracurium; neuromuscular blocking agent.
48. What is a generic name of Tracrium, and what type of drug is it?
Atracurium; neuromuscular blocking agent.
49. What do neuromuscular blocking agents do?
They cause skeletal muscle relaxation and paralysis.
50. Why do we administer sedatives, anesthetics, analgesics, and neuromuscular blocking agents to mechanically ventilated patients?
To help achieve patient-ventilator synchrony.
51. What is the most commonly administered anesthetic agent that is dissolved in a lipid emulsion for intravenous delivery?
52. When giving a patient a neuromuscular blocking agent, what two other types of drugs must be given?
Sedatives and analgesics
53. What is another common name for sedatives?
54. What is the most common use of Succinylcholine?
It is used to help with endotracheal intubation.
55. The physician is preparing to perform a bronchoscopy on a patient with suspected lung cancer. Which of the following would you recommend for conscious sedation?
56. What can be given to reverse the paralyzing effects of nondepolarizing agents?
Edrophonium (Tensolin) and neostigmine (Prostigmin)
57. What is a common side effect of narcotic analgesic agents?
58. What are the indications for administering sedatives?
To decrease anxiety, decrease agitation, minimize sleep deprivation, and minimize patient-ventilator dyssynchrony in non-conventional modes of ventilation.
59. What are the side effects of benzodiazepine tranquilizers?
Hypotension, hypoventilation, and lactic acidosis
60. What are narcotic opiate analgesics primarily used for?
They are used primarily for pain relief, and their secondary use is for sedation and anxiety relief.
61. What are the adverse reactions of narcotic opiate analgesics?
Nausea and vomiting, respiratory depression, bradycardia, hypotension, muscle twitching/convulsions, histamine release, immune suppression, and addiction.
62. What can be given for the immediate reversal of narcotic agents?
63. What are the four levels of sedation?
Minimal, moderate, deep, and anesthesia
64. What are the indications for paralytic agents?
The indications include patient-ventilator dyssynchrony, dynamic hyperinflation, ICP management, facilitating intubation, and reducing O2 consumption and CO2 production.
65. What is the most common depolarizing agent?
66. What agent is used for sedation in mechanically ventilated patients?
67. What agent is used for the dilation of pulmonary vessels?
68. What is a depolarizing agent that is metabolized by plasma cholinesterase?
69. What is the most immediate and life-threatening adverse effect associated with both depolarizing and non-depolarizing agents?
70. Which of the following are given to patients to reduce anxiety, provide amnesia, and improve tolerance to mechanical ventilation?
71. Which of the following barbiturates has a long-acting duration of action and a hypnotic effect of 4–12 hours?
72. What agent is used during mechanical ventilation for sedation and maintenance of anesthesia?
73. Benzodiazepines are normally well absorbed in what?
The gastrointestinal (GI) tract
74. Benzodiazepines can decrease what?
The mean arterial pressure, stroke volume, cardiac output, and systemic vascular resistance.
75. The Ramsay Scale is not suitable for what types of patients?
Paralyzed patients, since they cannot perform required commands.
The use of drugs during mechanical ventilation plays a crucial role in providing comfort and safety to patients in the ICU. Sedatives, including benzodiazepines, neuroleptics, anesthetic agents, and opioids, help to relieve anxiety, manage pain, and induce sleep.
Paralytic agents, such as depolarizing and nondepolarizing agents, are used to provide deep muscle relaxation and maintain mechanical ventilation. The careful selection and administration of these drugs is essential for effective ventilatory support and ensuring positive patient outcomes.
Check out our full guide on ventilator management if you want to learn more. Thanks for reading, and, as always, breathe easy, my friend.
John Landry is a registered respiratory therapist from Memphis, TN, and has a bachelor's degree in kinesiology. He enjoys using evidence-based research to help others breathe easier and live a healthier life.
- Clinical Application of Mechanical Ventilation. 4th ed., Cengage Learning, 2013.
- Pilbeam’s Mechanical Ventilation: Physiological and Clinical Applications. 6th ed., Mosby, 2015.
- Egan’s Fundamentals of Respiratory Care. 12th ed., Mosby, 2020.
- Rau’s Respiratory Care Pharmacology. 10th ed., Mosby, 2019.