Mixed Deck — All NBCRNA Topics Flashcards

What is the hourly maintenance fluid rate for an 11-pound infant?

Answer: 20 mL/h

Explanation: The hourly maintenance fluid rate for an 11-pound infant is typically calculated using the Holliday-Segar method, which suggests a rate of approximately 4 mL/kg/hour for the first 10 kg of body weight. For an 11-pound infant (approximately 5 kg): 4 mL/kg/hour × 5 kg = 20 mL/hour

The Bain circuit (Mapleson D modification) is a co-axial design where the inner tube carries what?

Answer: Fresh gas flow to the patient end

In the Bain circuit, the inner tube delivers fresh gas to the patient end while exhaled gases travel through the outer corrugated tube to the APL valve.

The circle breathing system uses soda lime to do what?

Answer: Absorb carbon dioxide from exhaled gases

Soda lime (primarily calcium hydroxide with sodium and potassium hydroxide) absorbs exhaled CO2 through a chemical reaction, allowing low-flow rebreathing circuits.

Ketamine produces dissociative anesthesia primarily through which receptor mechanism?

Answer: NMDA receptor antagonism

Ketamine blocks NMDA (N-methyl-D-aspartate) glutamate receptors, producing dissociative anesthesia, analgesia, and amnesia.

LAST (Local Anesthetic Systemic Toxicity) initial CNS symptoms include which finding?

Answer: Perioral numbness and metallic taste, progressing to seizures

LAST typically presents with CNS excitation (perioral tingling, tinnitus, metallic taste, restlessness, seizures) before CNS depression and cardiovascular collapse.

Rapid sequence induction (RSI) is indicated in patients at risk for pulmonary aspiration and includes preoxygenation followed by what drug sequence?

Answer: Induction agent + succinylcholine (or rocuronium), no mask ventilation

Classic RSI uses an induction agent with succinylcholine (or high-dose rocuronium for a modified RSI) without positive-pressure mask ventilation to minimize aspiration risk before cuff inflation.

What does a sustained upslope (shark fin appearance) in the capnography waveform indicate?

Answer: Obstructive airway disease or bronchospasm

A prolonged, slanted upslope on capnography (shark fin) reflects uneven CO2 elimination from lung units with different time constants, characteristic of obstructive disease.

The intubating laryngeal mask airway (ILMA/Fastrach) differs from a standard LMA in that it is designed to:

Answer: Allow blind or fiberoptic-guided endotracheal tube placement through the LMA

The ILMA has a rigid curved shaft, epiglottic elevating bar, and detachable airway tube designed to guide a specially designed endotracheal tube through the LMA into the trachea.

Which anatomical feature makes nasotracheal intubation contraindicated in patients with basilar skull fractures?

Answer: Risk of intracranial placement through cribriform plate defects

Basilar skull fractures can disrupt the cribriform plate, creating a potential path for a nasal tube to enter the cranial vault rather than the trachea.

Saddle block is a form of spinal anesthesia providing perineal anesthesia; it is achieved by using which technique?

Answer: Hyperbaric solution injected with patient sitting upright for 5–10 minutes

A saddle block uses a small volume of hyperbaric local anesthetic with the patient sitting; gravity restricts spread to the sacral nerve roots (S2–S5), anesthetizing the perineal 'saddle' area.

Train-of-four (TOF) monitoring is used to assess what?

Answer: Degree of neuromuscular blockade

TOF monitoring applies four supramaximal electrical stimuli to a peripheral nerve and counts the resulting muscle twitches to quantify the degree of non-depolarizing neuromuscular blockade.

Which technique is used to minimize the risk of accidental esophageal extubation during patient positioning after intubation?

Answer: Auscultation and capnography confirmation after every position change

Repositioning the patient can cause tube migration; confirming bilateral breath sounds and continuous capnography waveform after each position change detects displacement immediately.

Which vasopressor is currently recommended as the first-line treatment for spinal hypotension during cesarean delivery?

Answer: Phenylephrine

Phenylephrine is the first-line vasopressor for spinal hypotension in obstetrics because it maintains uteroplacental blood flow better than ephedrine and is associated with less fetal acidosis.

A thoracic epidural for post-thoracotomy analgesia is most effective because it blocks which nerves?

Answer: Intercostal nerves (T4–T8) and sympathetic chain at operative levels

Thoracic epidural analgesia blocks intercostal nerves at the surgical levels, providing superior pain relief that reduces splinting, improves respiratory mechanics, and decreases pulmonary complications.

Interscalene brachial plexus block provides the best anesthesia for surgery on which area?

Answer: Shoulder and proximal humerus

The interscalene approach targets the brachial plexus at the C5–C7 roots, providing excellent coverage of the shoulder, clavicle, and proximal humerus while often missing the ulnar nerve (C8–T1).

On the anesthesia machine, the fail-safe valve is designed to prevent the delivery of hypoxic gas mixtures by doing what?

Answer: Proportionally reducing nitrous oxide flow when oxygen pressure drops

The fail-safe (oxygen failure protection device) shuts off or proportionally reduces the flow of N2O and other gases when the oxygen supply pressure falls below a threshold.

A patient with an emergent stroke comes for an embolization procedure. The patient is allergic to morphine and sulfonamides. He has a history of gout, hypertension, gastrointestinal bleeding, and reflux. Which medication should be avoided in the postoperative orders?

Answer: Ketorolac (Toradol)

Explanation: Ketorolac is a nonselective inhibitor of prostaglandin synthesis. It is contraindicated in patients with a history of peptic ulcer disease and gastrointestinal bleeding.

A patient taking clopidogrel for a coronary stent placed 4 months ago requires urgent hip fracture surgery. The recommended management is:

Answer: Proceed with surgery; withholding antiplatelet therapy risks in-stent thrombosis

For urgent surgery, the risk of delaying outweighs the bleeding risk; proceeding is recommended, and neuraxial anesthesia would be contraindicated per ASRA guidelines if clopidogrel was recently taken.

The BEST indicator for CAD in the pre-operative assessment for vascular surgery patients is:

Answer: exercise tolerance.

Explanation: Exercise tolerance, typically assessed through an exercise stress test or similar methods, is considered the best indicator for coronary artery disease (CAD) in the pre-operative assessment for vascular surgery patients. It provides valuable information about cardiovascular function and the presence of ischemic symptoms during physical exertion, which is crucial in determining the patient's risk during surgery.

Spinal headache (post-dural puncture headache) is caused by what mechanism?

Answer: CSF leakage through the dural puncture causing traction on intracranial pain-sensitive structures

CSF leak through the dural hole reduces intrathecal pressure, causing orthostatic traction on meninges and intracranial vessels, producing the characteristic positional headache.