Muscle Relaxants
This muscle relaxant causes histamine release.
What is atracurium, mivacurium, succinylcholine or D-tubocurarine? The cardiovascular effects of neuromuscular blocking drugs occurs by three main mechanisms: (1) drug-induced histamine release; (2) effects at cardiac muscarinic receptors; or (3) effects on nicotinic receptors at autonomic ganglia.
This drug exerts its main CNS action by inhibiting the NMDA receptors.
What is ketamine? Whereas propofol, barbiturates, etomidate, and benzodiazepines exert much, if not all, of their pharmacologic effects via the GABA receptors, ketamine has only weak activity on the GABA receptors. Ketamine's mechanism of action is complex, with most of the effects due to interaction with NMDA receptors. Ketamine also interacts with MAOi, muscarinic, and opioids receptors, as well as voltage-sensitive calcium ion channels.
This opioid is metabolized by nonspecific esterases.
What is remifentanil? The short duration of action of remifentanil is due to its ester structure, which is metabolized by blood and tissue nonspecific esterases. Because of its nonspecific metabolism, its duration of action is not prolonged in patients with pseudocholinesterase deficiency.
This anticholinergic medication is given inhaled due to its bronchodilating properties.
What is ipratropium? Medications effective in the management of acute exacerbations of bronchial asthma include the rapid-onset inhaled β2-adrenergic receptor agonists (e.g., albuterol, pirbuterol, terbutaline), anticholinergic drugs (e.g., inhaled ipratropium), and IV corticosteroids. In an acute attack, ipratropium (slower in onset than β2-adrenergic receptor agonists) can be effective when used in combination with the rapid-onset β2 agonists.
After a 2-hour vertical gastric banding procedure under desflurane, oxygen, and remifentail anesthesia, the trocar is removed and the wound is closed. Upon emergence the most likely scenerio is this.
What is pain? Although it effectively suppresses autonomic and hemodynamic responses to painful stimuli and decreases respirations as well, its rapid dissipation of opioid effect produces rapid onset of postoperative pain (in painful surgical operations), unless other analgesics are administered for postoperative pain before stopping the infusion
This dibucaine number will result in a block duration of 1-3 hours.
What is dibucaine number of 20-30? People with a normal dibucaine number of 70 to 80 are homozygous for the normal typical plasma cholinesterase and have the normal 5- to 10-minute neuromuscular blockade. People who are heterozygous (incidence of 1/480) for the atypical plasma cholinesterase have a dibucaine number of 50 to 60 and a block duration of 20 minutes. Patients who are homozygous for the atypical plasma cholinesterase (incidence 1/3200) have a dibucaine number of 20 to 30 and a block duration from 1 to 3 hours.
This is the most common reason for patients to rate anesthesia with etomidate as unsatisfactory.
What is PONV? Etomidate is associated with a high incidence of nausea and vomiting (greater than after thiopental), pain on injection, thrombophlebitis, myoclonic movements, and sometimes hiccups. Nausea and vomiting is the most common reason patients rate anesthesia with etomidate as unsatisfactory.
This opioid has been associated with delirium and seizures.
What is meperidine? Normeperidine, a metabolite of meperidine with some CNS-stimulating properties, may cause delirium and seizures if the level is high enough. This is more likely in patients with renal impairment and are receiving meperidine over several days.
This medication binds to organophosphates and breaks alkyl phosphate-cholinesterase bond to restore the activity of acetylcholinesterase.
What is pralidoxime?
This is the maximum single recommended dose of lidocaine without epinephrine given by infiltration.
What is 300mg?
This antibiotic potentiates neuromuscular blockade.
What is aminoglycoside (neomycin, streptomycin, gentamicin, tobramycin, amikacin) and the lincosamides (clindamycin and lincomycin)? Macrolides (erythromycin and azithromycin), tetracyclines, penicillins, and cephalosporins do not affect neuromuscular blockade.
Sedation with this drug is most likely to resemble normal sleep.
What is dexmedetomidine? Dexmedetomidine has several desirable effects, especially in the neurosurgical ICU, including sedation, analgesia, and little effect on respiratory drive. Its sedative properties resemble normal sleep in that the sedated patient can be easily aroused with stimulation and then rapidly fall back to sleep after stimulation ends.
This opioid reaches steady state in less than 1 hour of continuous infusion.
What is remifentanil? Approximately 8 hours are required to reach the steady state with alfentanil and sufentanil, whereas fentanyl and morphine have not achieved the steady state concentration even after 10 hours of continuous infusion.
This temperature derangement can occur with atropine administration.
What is fever?
This alpha-antagonist produces an irreversible blockade.
What is phenoxybenzamine? Phenoxybenzamine produces an irreversible α-adrenergic blockade. Once phenoxybenzamine’s α blockade develops, even massive doses of sympathomimetics are ineffective until phenoxybenzamine’s action is terminated by metabolism.
This muscle relaxant is eliminated the most by renal excretion.
Immediately after injection of dexmedetomidine, this occurs to the blood pressure.
What is BP initially increases? After an IV injection, the BP initially increases (due to peripheral α stimulation), then within 15 minutes returns to normal and is followed by an approximately 15% decrease in BP within an hour. This is related to its CNS α-adrenergic stimulation overriding the peripheral effects.
This opioid has anticholinergic properties including tachycardia (not bradycardia typically seen with opioids).
What is meperidine? Meperidine is structurally similar to atropine and possesses mild anticholinergic properties. In contrast to other opioid-receptor agonists, meperidine rarely causes bradycardia but causes tachycardia.
These three medications are used to treat organophosphate poisoning.
What is atropine, pralidoxime, and benzodiazepines?Atropine is administered in doses of 2 to 6 mg and is repeated every 5 to 10 minutes until secretions begin to decrease. In most cases, 2 mg every 8 hours is needed. However, doses of 15 to 20 mg are not uncommon, and occasionally doses over 1000 mg have been needed. Pralidoxime 600 mg removes the organophosphate compounds from acetylcholinesterase and is often used in conjunction with atropine. Benzodiazepines are often administered to counter the effects of the nerve gases on the GABA system. Pyridostigmine is an appropriate medication for prophylaxis against possible nerve agent exposure but not used for treatment.
What is diuresis? Dantrolene is a skeletal muscle relaxant that is effective in the treatment of malignant hyperthermia. Dantrolene is formulated with mannitol (300 mg mannitol/20 mg dantrolene) so that diuresis is promoted during dantrolene therapy. Myoglobinuria from malignant hyperthermia–associated muscle breakdown accumulates in the renal tubules and can cause kidney failure if urine output is not maintained. Dantrolene works within the muscle cell to reduce intracellular levels of calcium.
This muscle relaxant should be administered with caution to patients on echothiophate.
What is succinylcholine or mivacurium? Echothiophate is an organophosphate that inhibits acetylcholinesterase as well as pseudocholinesterase, which is responsible for the metabolism of succinylcholine and ester-type local anesthetics. It does this by forming a phosphorylated complex with acetylcholinesterase. The topical solution is instilled in the eye for treatment of refractory open-angle glaucoma. The amount of drug absorbed may be sufficient to inhibit acetylcholinesterase and cause prolongation in the duration of action of succinylcholine or mivacurium, so it is recommended to wait at least 3 weeks after the stoppage of echothiophate before administration.
This intravenous anesthetic can trigger acute intermittent porphyria.
What is etomidate? An acute intermittent porphyria attack can be triggered by a variety of conditions, including starvation, dehydration, stress, sepsis, and some drugs, such as etomidate and barbiturates.
Methadone-induced constipation could be reversed without loss of analgesic effect with this opioid antagonist.
What is methylnaltrexone? Naloxone, naltrexone, and nalmefene are opioid receptor antagonists that can reverse the central and peripheral effects of opioids (ie. methadone). Methylnaltrexone is a quaternary ammonium opioid receptor antagonist that does not penetrate the CNS (ie does not reverse analgesia) but does antagonize peripheral opioid receptors (ie blocks the GI tracts opioid receptors and can treat opioid-induced constipation). Because of its structure, it is not absorbed after oral administration, so it is administered by injection.
This anticholinergic does not produce central anticholinergic syndrome.
What is glycopyrrolate? The toxic state known as central anticholinergic syndrome requires passage of the drug across the BBB and therefore precludes glycopyrrolate from causation.
Aprepitant is an antagonist of this receptor.
What is NK1? Aprepitant is an NK1 antagonist (substance P antagonist) with a long half-life of 9-13 hours. It is orally administered for the prevention and treatment of PONV, although it seems better in preventing vomiting. NK1 antagonists may act synergistically with 5HT-3 antagonists and/or dexamethasone. Aprepitant is not associated with QTc prolongation. Although marked for its antiemetic effects, it has some anxiolytic and mild antidepressant effects as well.