Pharm/ Malignat hyperthermia

Malignant Hyperthermia

  • Definition: A severe reaction to certain general anesthetics and muscle relaxants (namely, inhaled gases and succinylcholine).

  • Causes:

    • Primarily linked to anesthetic agents: inhaled anesthetics and succinylcholine.

  • Genetic Link:

    • Not genetically linked but screening is essential before surgeries.

    • Screening Question: "Do you have any blood relatives who have experienced malignant hyperthermia?"

    • Reason: To prevent potential complications during anesthesia.

  • Signs and Symptoms:

    • Rise in body temperature (hyperthermia).

    • Tachycardia (rapid heartbeat).

    • Tachypnea (rapid breathing).

    • Muscle rigidity.

  • Treatment:

    • Medication: Dantrolene is administered in high doses.

    • Cooling Measures: Essential to manage hyperthermia.

    • Pathophysiology: Results in a calcium 'dump' in the body, leading to a hyper metabolic state.

    • Dantrolene prevents muscle contractions caused by this state.

Balanced Anesthesia

  • Definition: A technique in anesthesia to maximize efficacy and minimize dosage by using multiple agents.

  • Goal: To achieve synergistic effects, meaning that each drug contributes to different aspects of anesthesia, leading to a more effective overall outcome with less dosage.

  • Components:

    • Administration of minimal doses of multiple anesthetic drugs (Option A is correct).

    • Inhaled anesthetics (Option B) and IV anesthetics (Option C) can also be part of the regimen but are not the defining characteristic.

  • Clinical Implications: Balancing effectiveness vs. side effects while optimizing patient safety.

Moderate Sedation & Monitored Anesthesia Care (MAC)

  • Overview: Typically involves a state of sedation where the patient does not fully lose consciousness.

  • Characteristics:

    • Patients can retain some cognitive functions (e.g., responding to questions) but do not remember the procedure due to medication effects.

  • Common Drugs Used:

    • Midazolam: A benzodiazepine causing sedation and amnesia.

    • Fentanyl: Commonly used opioid for pain management.

    • Propofol: Can be used for conscious sedation leading to a deeper state of sedation but still often does not require mechanical ventilation.

  • Setting: Usually performed in outpatient settings or surgical centers with brief recovery periods after sedation (around 1 hour).

  • Examples of Procedures: Often used in situations like colonoscopies or carpal tunnel surgeries.

Local Anesthetics

  • Definition: Medications that provide localized pain relief without loss of consciousness.

  • Administration Routes:

    • IV Injection: Used for pain control or arrhythmias.

    • Infiltration: Injection around a targeted area for surgeries, such as suturing a laceration.

    • Topicals: Surface application for superficial numbing effects.

    • Regional and Nerve Blocks: Injecting around specific nerves to block sensations in targeted areas (e.g., knee surgeries).

    • Spinal and Epidural: Utilized for major surgeries and labor pain management.

  • Example Medications:

    • Lidocaine: Common local anesthetic for infiltration.

    • Novocaine: Often used in dental procedures.

    • Bupivacaine and Ropivacaine: Longer-lasting anesthetics for nerve blocks.

  • Risks: Potential for systemic toxicity which can lead to cardiovascular and respiratory dysfunction.

  • Preventative Measures:

    • Administering local anesthetics with epinephrine to limit spread and prevent systemic absorption.

    • Maximum drug dosing charts to avoid dosage errors.

  • Safety Concerns: Epinephrine should not be used in areas like fingers, toes, or nose due to risk of necrosis from vasoconstriction.

Neuromuscular Blocking Drugs

  • Function: Paralyze skeletal muscle, which does not provide analgesia or sedation alone.

  • Clinical Considerations: Must be accompanied by sedation (e.g., using benzodiazepines or opioids) since patients remain conscious but unable to move.

  • Patient Monitoring: Requires mechanical ventilation as patients will not be able to breathe on their own without assisted ventilation.

Upcoming Topics: Antilipemic and Diuretic Drugs

  • Learning Objectives:

    • Discuss hyperlipidemia and its implications.

    • Describe the anatomy and function of the renal system.

    • Understand lipoproteins and their cardiovascular effects.

    • Learn the classifications of antilipemic medications.

    • Explore the relationship between the renal system and blood pressure regulation.

  • Core Lipids:

    • Triglycerides: Primary energy source stored in adipose tissues.

    • Cholesterol: Essential for cellular structures and function, but elevated levels pose health risks.