Pulmonary edema and prolonged awakening after nasal naphazoline application in a transspenoidal hypophysectomy patient

[Neuroanesthesia]

Anesthesiological challenges during craniotomy result from the anatomically related low compensatory capacity of the intracranial space in response to increased volume and the low ischemic tolerance of brain tissue. The anesthetic agents used should therefore not increase the intracranial volume and improve the ischemic tolerance. An acute life-threatening increase of intracranial pressure can be temporarily treated by hyperventilation until measures, such as osmotherapy and infusion of intravenous anesthetics become effective. During an operation the homeostatic parameters including blood volume, blood pressure, partial pressure of carbon dioxide and oxygen in blood, plasma glucose concentration and core body temperature have to be closely monitored and kept normal (6 Ns). Optimal implementation of anesthesia necessitates a detailed knowledge of the surgical approach and potential complications. Postoperatively, patients should be extubated as soon as possible to closely monitor cognitive function so that potential deterioration can be detected.

Oxymetazoline Metered Dose Spray: Factors Affecting Delivery Volume

OBJECTIVES

The current study compared the amount of oxymetazoline delivered by various anesthesia providers when holding the bottle in the upright and inverted position. Additionally, the amount delivered from a full bottle and a half-full bottle was also investigated.

METHODS

Using an analytical balance that was calibrated to zero, we evaluated the impact the position of the bottle and the volume of oxymetazoline in the bottle had on the amount being delivered by both anesthesia staff and trainees.

RESULTS

When using both filled and half-filled bottles, the amount delivered increased significantly when comparing the upright versus inverted position. With a full bottle, the amount delivered when the bottle was inverted increased almost 10-fold from 62 ± 80 to 606 ± 366 μL (p < 0.0001). Similarly, even with a half-filled bottle, the amount delivered increased in the inverted positions from 41 ± 48 to 645 ± 393 μL. Regardless of the scenario, we also noted significant variation from provider to provider.

CONCLUSIONS

Our results demonstrate that several factors may affect the amount of oxymetazoline delivered for metered dose bottles. Given the potential for severe end-organ effects with excessive dosage, alternative means of delivery are needed for its perioperative use.

Oxymetazoline and hypertensive crisis in a child: can we prevent it?

BACKGROUND

Oxymetazoline nasal spray is not FDA approved for use in children less than 6 years; however, its safety and efficacy are widely accepted, and it is in widespread use in children prior to procedures that may lead to epistaxis. We report a case of intraoperative oxymetazoline toxicity in a 4-year-old boy that led to a hypertensive crisis. While examining the possible causes for this problem, we became aware that the method of drug delivery led to an unanticipated overdose. The position in which the bottle is held causes pronounced variation in the quantity of oxymetazoline dispensed.

METHODS

To examine the impact that bottle position has on the volume delivered, we measured the volume of oxymetazoline dispensed with the bottle in the upright and inverted position. We also measured the volume of a drop of oxymetazoline dispensed from the bottle. Because an additional source of oxymetazoline exposure is from packing the nares with surgical pledgets, we analyzed the volume of oxymetazoline absorbed by each pledget.

RESULTS

Squeezing the bottle in the upright position results in a fine spray of fluid that averaged 28.9 ± 6.8 μl and was largely independent of effort. This volume is nearly identical to the measured volume of a drop of oxymetazoline, which was 30 μl. However, squeezing the bottle in the inverted position resulted in a steady stream of fluid, and the volume administered was completely effort dependent. Multiple tests in the inverted position demonstrated an average volume of 1037 ± 527 μl, with a range of 473-2196 μl. Lastly, the volume of oxymetazoline absorbed by each surgical pledget was 1511 ± 184 μl.

DISCUSSION

Our testing indicates that bottle position during oxymetazoline administration can cause up to a 75-fold increase in intended drug administration.