Abstract
BACKGROUND: Vasoconstrictors and local anesthetics are commonly administered using a squeeze bottle atomizer to the nasal mucosa to reduce edema, limit bleeding, and provide analgesia. Despite widespread use, there are few clinical guidelines that address technical details related to safe administration. The purpose of this study was to quantify, via simulation, the amount of liquid delivered to the nasal mucosa when patients are in the supine and upright positions and administration parameters that would reliably provide the desired amount of medication per spray.
METHODS: A convenience sample of 10 anesthesia residents was studied. Providers were instructed to use a 25-mL dip and tube nasal squeeze bottle to administer the test solution (sterile water) to a mannequin in the upright (90 degrees elevation) and supine (0 degrees elevation) position. After mannequin testing, additional testing was completed with the spray bottles at 0 degrees, 15 degrees, 30 degrees, 45 degrees, and 90 degrees to determine the relationship between the angles of administration and the amount of liquid dispensed.
RESULTS: The mean volume delivered per spray was substantially greater when administered in the supine position (0.56 +/- 0.22 mL) compared with the upright position (0.041 +/- 0.02 mL, difference = 0.52 mL, 95% confidence interval [CI], 0.37-0.67 mL, P < .001). Converting the administered volume to the dose of phenylephrine that would be administered using our standard 0.25% solution, an estimated additional 1300 mcg is delivered per spray in the supine position compared with the upright position (95% CI, 925-1675 mcg, P < .001). Administration with a delivery angle of = 30 degrees resulted in significantly more volume than when the bottle was oriented at a 90 degrees angle. The volume dispensed at 45 degrees was not different from the volume delivered at 90 degrees (0.032 +/- 0.006 mL vs 0.030 +/- 0.005 mL, P = .34).
CONCLUSIONS: We found a 14-fold increase in the volume (ie, dose) delivered per spray when a nasal squeeze bottle was used with a mannequin in the supine position compared with the upright position. Given the reported toxicity from the use of intranasal medication and the inadvertent overdosing that occurs when squeeze bottle atomizers are used in clinical practice, our data suggest that all intranasal drugs should be administered with a precise, metered-dose device. If a metered-dose device is unavailable, the medication should be delivered at an angle of = 45 degrees; however, we recommend administering the drug with the patient in the sitting position and the bottle at 90 degrees because only a small change in angle below 45 degrees will result in a substantial increase in medication delivered.
