From the Guidelines
The risk of pulmonary aspiration with midazolam is low when used at standard sedative doses, typically 1-5 mg intravenously, and in the absence of other risk factors [ 1 ].
Key Considerations
- The major side effect of midazolam is respiratory depression, which can increase the risk of aspiration [ 1 ].
- Midazolam-induced respiratory depression may be an administration-related phenomenon, with more rapid administration resulting in a greater number of apneic episodes [ 1 ].
- Patients should be closely monitored for signs of respiratory depression and aspiration, especially when midazolam is used in combination with other sedatives or in patients with a history of gastroesophageal reflux disease or other conditions that increase the risk of aspiration [ 1 ].
- It is recommended to use midazolam in a controlled setting with adequate suction equipment and personnel trained in airway management [ 1 ].
Patient-Specific Factors
- Patients older than 60 and those with ASA physical status III or greater require a dose reduction of 20% or more [ 1 ].
- Patients with a history of benzodiazepine tolerance may require larger doses [ 1 ].
- Patients with hepatic or renal impairment may have reduced midazolam clearance [ 1 ].
From the Research
Aspiration Risk with Midazolam
The aspiration risk with midazolam is a significant concern, as it can cause respiratory depression and impair airway protection.
- Studies have shown that midazolam can increase the risk of pharyngeal dysfunction, misdirected or incomplete swallowing, and penetration of bolus to the airway 2.
- Midazolam has been found to prolong apnea before swallowing and increase the number of swallows followed by inspiration, which can impair airway protection and increase the risk for pulmonary aspirations 2.
- The use of midazolam for sedation before procedures has been associated with an increased risk of respiratory depression, as mirrored by hypercapnia and acidosis 3.
- The effects of midazolam on respiratory muscles in humans have been found to increase total pulmonary resistance and elicit a compensatory load response characterized by an increase in inspiratory intercostal and expiratory abdominal muscle activities, whereas diaphragmatic contribution is reduced 4.
Factors Influencing Aspiration Risk
Several factors can influence the aspiration risk with midazolam, including:
- Dose and route of administration: Higher doses of midazolam may increase the risk of respiratory depression and aspiration 2, 5.
- Combination with other sedatives: The use of midazolam in combination with other sedatives, such as morphine, may increase the risk of pharyngeal dysfunction and aspiration 2.
- Patient characteristics: Patients with pre-existing respiratory or gastrointestinal conditions may be at increased risk of aspiration with midazolam 3, 6.