Perioperative Care & Patient Monitoring Flashcards

Near-infrared spectroscopy (NIRS) used as cerebral oximetry during anesthesia measures:

Answer: Regional cerebral oxygen saturation (rSO2) noninvasively

Cerebral NIRS measures regional cerebral oxygen saturation by detecting reflected near-infrared light absorbed by oxygenated and deoxygenated hemoglobin in underlying brain tissue.

The primary purpose of preoperative fasting (NPO) guidelines before elective surgery is to:

Answer: Reduce the risk of pulmonary aspiration of gastric contents

Preoperative fasting reduces gastric volume and acidity to minimize the risk of regurgitation and aspiration of gastric contents during anesthesia induction, which can cause severe pulmonary injury.

According to current ASA preoperative fasting guidelines, clear liquids (water, clear juice, black coffee) may be consumed up to how many hours before elective surgery in healthy adults?

Answer: 2 hours

The ASA recommends a minimum 2-hour fast for clear liquids, as they empty rapidly from the stomach and pose minimal aspiration risk when consumed up to 2 hours before induction.

Capnography is sometimes referred to as the 'fifth vital sign' in anesthesia because it simultaneously provides information about:

Answer: Ventilation, circulation, and metabolic state

Capnography reflects ventilation (CO2 elimination), circulation (CO2 delivery to lungs), and metabolism (CO2 production), making it uniquely informative across multiple physiologic domains.

Postoperative cognitive dysfunction (POCD), characterized by memory impairment and reduced cognitive function persisting after surgery, is most prevalent in which patient population?

Answer: Elderly patients older than 65 years

POCD is significantly more prevalent in elderly patients (>65 years) due to reduced cognitive reserve, pre-existing neurodegenerative changes, and increased neuroinflammatory response to anesthesia and surgery.

Which pharmacologic agent is used in the PACU to reverse opioid-induced respiratory depression while preserving some degree of analgesia at low doses?

Answer: Naloxone (opioid receptor antagonist) titrated in small IV doses

Naloxone titrated in small IV increments (40–80 mcg) reverses opioid-induced respiratory depression while minimizing complete reversal of analgesia and preventing acute pain crisis.

Which pain assessment scale is most commonly used to evaluate postoperative pain intensity in conscious, communicative adult patients?

Answer: Numerical Rating Scale (NRS) scored 0–10

The NRS 0–10, where 0 = no pain and 10 = worst imaginable pain, is the standard validated tool for self-reported pain intensity assessment in conscious adult surgical patients.