What is the antidote for Benzodiazepine overdose?
[It is a competitive inhibitor that may cause seizures or arrhythmias and is contraindicated in patients with elevated intracranial pressure or status epilepticus.]
Epidural is contraindicated in which patients?
Patients with hypertophic cardiomyopathy or cyanotic heart disease
[Spinal anesthesia is also contraindicated in these patients. Sympathetic denervation causes decreased afterload, which worsens these conditions.]
An example of a nondepolarizing agent is?
What is the most common PACU complication?
Nausea and vomiting
Why are infected tissues difficult to anesthetize with local anesthetic?
[Inflammation causes metabolic acidosis which lowers the pH of affected tissues. Such inflammatory conditions alter the pharmacokinetics and pharmacodynamics of local anesthetics by reducing their interactivities with lipid bilayers and/or membrane lipids.]
In which patients is Ketamine contraindicated as an induction agent?
Patients with head injuries
[Ketamine causes increased cerebral blood flow]
Which inhalation induction agent can cause seizures?
Which inhalation induction agent is characterized by slow onset and offset, highest degree of cardiac depression and arrhythmias, and is the least pungent (good for children)?
[Halothane hepatitis = fever, eosinophilia, jaundice, increased LFTs]
What are contraindications to administering epinephrine with a local anesthetic?
- Unstable angina
- Uncontrolled hypertension
- Tissues with poor collaterals (I.E. Penis or ears)
- Uteroplacental insufficiency
What dose of Lidocaine can be used as a local anesthetic?
0.5 cc/kg of 1% lidocaine
Which 2 drugs can be used to reverse nondepolarizing agents?
Neostigmine or Edrophonium
[They block acetylcholinesterase, thus increasing acetylcholine. Atropine or glycopyrrolate should be given with Neostigmine or Edrophonium to counteract effects of generalized acetylcholine overdose]
What is the most potent narcotic?
[Sufentanil and remifentanil are very fast acting narcotics with short half lives.]
What are the contraindications to using Succinylcholine as a paralytic?
- Severe burns
- Neurologic injury
- Neuromuscular disorders
- Spinal cord injury
- Massive trauma
- Acute renal failure
[These are contraindications because of the hyperkalemia caused by Succinylcholine depolarization]
Which intravenous induction agent is fast acting but causes decreases in cerebral blood flow, metabolic rate, and blood pressure?
Sodium thiopental (Barbiturate)
Where are opioids metabolized and excreted?
- Metabolized in the liver
- Excreted in the urine via the kidneys
Which inhalation induction agent lowers brain O2 consumption with no increase in intracranial pressure, thus making it good for use in neurosurgery?
What are the relative lengths of action of lidocaine, procaine, and bupivacaine?
Bupivacaine > Lidocaine > Procaine
Which inhalation induction agent is characterized by fast onset, less laryngospasm, and is less pungent (good for mask induction)?
What are 3 potential side effects of Succinylcholine?
- Malignant hyperthermia
- Open-angle glaucoma
How might a postop myocardial infarction present?
- No pain or ECG changes
- Increased filling pressures
Where is spinal anesthesia injected?
Into the subarachnoid space
By what mechanism of action do local anesthetics work?
They increase action potential threshold, preventing Na influx
[Side effects include tremors, seizures, tinnitus, and arrhythmias. CNS symptoms occur before cardiac symptoms.]
Malignant hyperthermia is caused by a defect in what?
[Calcium released from the sarcoplasmic reticulum causes muscle excitation-contraction syndrome.]
What can be added to epidural anesthesia to cause decreased heart rate and blood pressure?
Which surgical procedures are considered low risk (Less than 1% cardiac risk)?
- Endoscopic procedures
- Superficial procedures
- Cataract surgery
What is the most likely cause of a sudden transient drop in end-tidal CO2 in an intubated patient undergoing surgery?
Likely became disconnected from the vent
[Could also be due to pulmonary embolism, but the patient would have hypotension.]
Which surgical procedures are considered high risk (greater than 5% cardiac risk)?
- Any emergent operation (especially in the elderly)
- Most aortic, major vascular, and peripheral vascular surgeries
[Carotid endarterectomy is considered moderate risk surgery]
Which inhalation induction agent is characterized by fast onset, minimal myocardial depression, and tremors at induction?
Nitrous oxide (NO2)
Higher volume hospitals are associated with lower mortality for which 2 procedures?
- Abdominal aortic aneurysm repair
- Pancreatic resection
Where should the endotracheal tube be placed with respect to the carina?
2 cm above the carina
What are 5 potential complications of epidural and spinal anesthesias?
- Urinary retention (need urinary catheter)
- Abscess/hematoma formation
- Respiratory depression (with high spinal)
Which muscle(s) is/are the first to be paralyzed and the last to recover?
Neck and face muscles
Which 3 local anesthetics are esters?
[Higher risk of allergic reactions due to PABA analogue]
What is the first sign of malignant hyperthermia?
Increased end-tidal CO2
[Followed by fever, tachycardia, rigidity, acidosis, and hyperkalemia.]
What are the appropriate steps to take if a patient develops acute hypotension and bradycardia while receiving epidural anesthesia?
- Turn epidural down
- Give fluids
- Administer Phenylephrine
- Administer Atropine
[T-5 epidural can affect cardiac accelerator nerves]
Which 3 local anesthetics are amides?
[All have an "I" in the first part of the name. Rarely cause allergic reactions.]
Which nondepolarizing muscle relaxant is metabolized by the kidneys, acts slowly, and is long-lasting?
[Most common side-effect is tachycardia]
What can be administered with local anesthetics to allow higher doses of anesthetic to be used?
[Causes local anesthetic to remain local]
Which surgical procedures are considered intermediate risk (Less than 5% cardiac risk)?
- Carotid endarterectomy
- Head and neck surgery
- Intraperitoneal and intrathoracic surgery
- Orthopedic surgery
- Prostate surgery
Which Benzodiazepine is contrandicated in pregnancy because it crosses the placenta?
What is the relative length of action of Ativan (Lorazepam), Valium (Diazepam), and Versed (Midazolam)?
- Short acting - Versed (Midazolam)
- Intermediate acting - Valium (Diazepam)
- Long acting - Ativan (Lorazepam)
Which nondepolarizing muscle relaxant undergoes Hofman degradation and can cause Histamine release?
[Hofmann degradation is the organic reaction of a primary amide to a primary amine (one fewer carbon), releasing CO2.]
Which intravenous induction agent causes fewer hemodynamic changes, is fast acting and can lead to adrenocortical suppression with continuous infusion?
What is the antidote for opioid overdose?
Which narcotic causes histamine release, leading to hypotension?
[Demerol and Fentanyl do not cause histamine release.]
Which two pre-operative conditions are associated with the most postop hospital mortality?
- Renal failure
What is the typical sequence in rapid sequence intubation?
What are 5 indications for rapid sequence intubation?
- Recent oral intake
- Delayed gastric emptying
- Bowel obstruction
[UpToDate: Rapid sequence intubation (RSI) is the virtually simultaneous administration of a sedative and a neuromuscular blocking (paralytic) agent to render a patient rapidly unconscious and flaccid in order to facilitate emergent endotracheal intubation and to minimize the risk of aspiration. Preoxygenation is required to permit a longer period of apnea without clinically significant oxygen desaturation. Bag-mask ventilation is avoided during the interval between drug administration and endotracheal tube placement, thereby minimizing gastric insufflation and reducing the risk of aspiration.
Indications — RSI is the standard of care in emergency airway management for intubations not anticipated to be difficult. Multiple large prospective observational studies confirm that the implementation of RSI has led to improved success and decreased complication rates for emergency intubations.
Contraindications — Contraindications to RSI are relative. Circumstances exist where neuromuscular blockade is undesirable due to the high likelihood of intubation or mechanical ventilation failure. Depending on clinical circumstances, particular sedative or neuromuscular blocking agents may be relatively contraindicated, due to the risk of potential side effects.]
Which receptors do narcotics (opioids) act on?
[Opioids = Morphine, Fentanyl, Demerol, Codeine]
What is the treatment for malignant hyperthermia?
Dantrolene (10mg/kg) = it inhibits Ca release and decouples excitation complex
[Other treatment includes cooling blankets, HCO3, glucose, and supportive care.]
Epidural anesthesia causes analgesia by what mechanism?
What can be added to epidural anesthesia to cause respiratory depression?
What is the definition of minimum alveolar concentration (MAC)?
The smallest concentration of inhalational agent at which 50% of patients will not move with incision
[An agent with a small MAC is more lipid soluble meaning it is more potent but slower to take effect]
What is the best determinant of esophageal vs tracheal intubation?
Which muscle(s) is/are the last to be paralyzed and the first to recover?
How much stronger is Fentanyl than Morphine?
Fentanyl is 80x stronger than Morphine
[It does not cross-react in patients with morphine allergy.]
Which narcotic can cause seizures?
[Seizures can result due to a buildup of normeperidine analogues. This is particularly the case in patients with renal failure.]
An example of a depolarizing agent is?
[The only one. It depolarizes the neuromuscular junction.]
Which intravenous induction agent is characterized by a very rapid distribution and onset/offset, amnesia, and sedation, but is not an analgesic, cannot be used in patients with egg allergies, and causes side effects such as hypotension and respiratory depression?
[Metabolized in the liver and by plasma cholinesterases]
Why should opioids be avoided in patients taking Monoamine Oxidase Inhibitors (MAOIs)?
The combination can cause hyperpyrexic Coma
Why do some Asians have prolonged paralysis following administration of Succinylcholine?
Higher incidence of atypical pseudocholinesterases in Asian population
What is the most likely cause of a sudden transient rise in end-tidal CO2 in an intubated patient undergoing surgery?
[Treat by increasing tidal volume or respiratory rate]
Which intravenous induction agent causes dissociation of thalamic and limbic systems, placing patients in a cataleptic state of amnesia and analgesia, and is associated with hallucinations, catecholamine release (increased CO2, tachycardia), increased airway secretions, and increased cerebral blood flow?
[Contraindicated in patients with head injury due to increased cerebral blood flow. Good for use in children]
How do nondepolarizing muscle relaxants work?
They inhibit the neuromuscular junction by competing with acetylcholine
[Patients with Myasthenia Gravis can have prolongation of the effects of these agents]
Which nondepolarizing muscle relaxant is metabolized by the liver and works fast and for an intermediate duration?
Which nondepolarizing muscle relaxant can be used in patients with liver and renal failure?
[It is not metabolized by the liver or kidneys but rather it undergoes Hofmann degradation]
In which situations is a caudal block particularly useful?
- Pediatric hernias
- Perianal surgery
[Administered through the sacrum]