Preprocedure oral intake

The clinician should provide the patient with preprocedure fasting guidelines. Historically, patients have been instructed to have nothing to eat or drink after midnight the night before the procedure to decrease the risk of gastric acid aspiration. However, these guidelines don’t address the:

• time of the procedure
• time the patient went to bed the night before the procedure
• variability associated with gastric emptying for solids and liquids.

Failure to address these variables can lead to dehydration, hypoglycemia, hypovolemia, increased irritability, enhanced preoperative anxiety, thirst, hunger, and headaches.

The ASA recently updated its practice guidelines for preoperative fasting based on studies that showed a reduced fasting interval did not increase the risk of pulmonary aspiration in normal, healthy individuals. (See ASA fasting guidelines.)

Pharmacologic agents

Combinations of carefully titrated sedative, analgesic, and hypnotic medications alter a patient’s level of consciousness and enhance cooperation. However, sedative and analgesic medications also may produce profound synergistic effects, which may lead to deep sedation or general anesthesia. Successfully producing a sedate, analgesic state and minimizing complications (respiratory distress, cardiovascular depression, and hypoxemia) requires an understanding of these medications as well as the reversal agents that may be needed if the level of sedation becomes deeper than intended. (See Pharmacologic agents: An overview.)

Note that benzodiazepines and narcotics are pharmacologically reversible, but propofol is not and may produce rapid, unpredictable effects, including respiratory arrest.

Propofol

Several professional organizations— including the American College of Gastroenterology, the American Society for Gastrointestinal Endoscopy, and the Society for Gastroenterology Nurses and Associates— have endorsed nonanesthesiologist or nurse-administered propofol administration. However, the Food

and Drug Administration (FDA) notes that propofol should be administered only by “persons trained in administering general anesthesia and not involved in the conduct of the surgical/diagnostic procedure.”

Here’s some background on the status of propofol administration by nonanesthesia providers:

• Reports of adverse patient events have been connected to non-anesthesia provider propofol administration. Over a decade ago, the Pennsylvania Patient Safety Reporting System received more than 100 reports in which propofol administration in untrained hands resulted in adverse patient events. Sixteen percent of those reports were classified as serious events, including four patient deaths.
• In 2009, Rex and colleagues reported that propofol is known to cause hypoventilation, hypotension, and bradycardia relatively frequently, but they posit that severe adverse events are rare.

In 2005, the American College of Gastroenterology petitioned the FDA to remove warnings about who can administer propofol from its package labeling. In a 2010 letter, the FDA denied the petition and noted that the warning “should help ensure that propofol is used safely.” Nonanesthesia providers who administer or monitor patients receiving propofol must recognize that the Institute of Patient Safety recognizes it as a high-risk medication. Propofol is not reversible and may produce rapid, unpredictable effects, including respiratory arrest. The prescribing clinician and nonanesthesia provider administering the sedation and monitoring the patient should possess advanced airway-management skills, demonstrate proficiency in managing cardiovascular complications, and recognize that propofol can induce deep sedative states and general anesthesia. Before administering this sedative, nurses should check their state board of nursing to ensure this care is within their scope of practice.