Use of sterile saline as a conduction agent for ultrasound visualization of central venous structures

Evaluation of saline versus gel as contact medium for ultrasonographic image quality

OBJECTIVES

Evaluate the time taken to visualize the internal jugular vein and carotid arteries, and subjective image quality assessed on a 0-100 visual analogic scale, on an ultrasound model using either traditional ultrasound gel or normal saline.

METHODS

Twenty-two anesthesiology residents and twenty anesthesiology faculty were blinded and randomized into four separate groups using gel and saline as a conduction medium, in different sequences.

RESULTS

Subjective image quality was 12.2 ± 4.2 better with gel than with saline (P < 0.01). Image acquisition time did not differ significantly between the two mediums. There was no significant difference in subjective image quality or time to image acquisition between faculty and residents.

CONCLUSIONS

Internal jugular vein and carotid artery identification time using ultrasonography were similar between gel and saline as conduction mediums. The difference in subjective image quality did not appear clinically relevant. Better image quality resulted in less time taken to identify the structures, as expected. We conclude that saline may be an effective alternative medium to gel for vessel imaging and access guidance. Further study in a clinical setting is warranted.

[Hygiene aspects in ultrasound-guided regional anesthesia]

BACKGROUND

Sterile and clean working conditions are one of the keystones of medical practice and this is also true for ultrasound-guided regional anesthesia. The routine clinical practice in ultrasound-guided regional anesthesia does not always comply with the principles of sterile and clean working conditions in medicine: therefore, patients are exposed to potential hazards regarding the transmission of pathogens via the ultrasound equipment.

OBJECTIVE

This article deals with the question of whether sterile working conditions in ultrasound-guided regional anesthesia are a relevant topic with medical and economic implications. Is it possible to implement the general recommendations for sterile working conditions in ultrasonography for the specific application of ultrasound-guided regional anesthesia?

MATERIAL AND METHODS

A search of the available literature and published guidelines in the field of sterile working conditions with ultrasound was carried out.

RESULTS

The association between cross-infections and ultrasound equipment is undeniable. Many methods for cleansing and disinfection of ultrasound equipment have been published. All these methods are associated with advantages and disadvantages. The direct sterilization of ultrasound probes with high-percentage alcohol can damage ultrasound probes (especially linear). The use of self-adhesive sterile ultrasound probe covers is a practical method to achieve sterile working conditions in ultrasound-guided regional anesthesia.

CONCLUSION

The use of sterile ultrasound probe covers and sterile ultrasound contact media is an important prerequisite to avoid cross-infection between patients. An appropriate scientific evaluation should serve as evidence in this field.