Introduction

Silver nitrate is commonly used to chemically cauterize a wound for hemostasis after debridement or treatment of hypergranulation tissue. It is an inorganic and radiodense material with antimicrobial properties that can be used as a solution or an applicator stick.¹ As a cauterizing agent, silver nitrate delivers free silver ions that can bind to the tissue and form an eschar and obstructing vessels.¹ On an applicator stick, silver nitrate is a small, dark tip. When exposed to water, the chemical activates, catalyzing a chemical reaction.² When applied to the site of the wound, this reaction seals the capillaries.

Indications for Use of Chemical Cauterization

Chemical cauterization through the use of silver nitrate can help accelerate the clotting process and achieve hemostasis on a variety of different wounds. Some of the common ones encountered include:

• Nosebleeds or anterior epistaxis: The application of silver nitrate to the mucous membrane or blood vessels in the nostril can control bleeding of the nose. It controls the bleeding associated with small vessels and ulceration of the nasal mucosa.³ When compared with other treatment modalities, silver nitrate has the highest success rate (80%) for controlling bleeding.⁴ Silver nitrate can also be used for vasomotor rhinitis when applied to the nasal mucosa.⁵
• Skin tag or wart removal: Silver nitrate can be used to eliminate unwanted skin tags and warts.⁶
• Hypergranulation tissue: Chemical cauterization with silver nitrate can remove hypergranulation tissues in stomas and wounds.⁴
• Wound epibole: Applied to epibole, silver nitrate may restart the healing process.⁷
• Aphthous stomatitis: Silver nitrate cautery can be an effective and rapid treatment option for pain relief in aphthous stomatitis.⁸
• Ulcerations: Application of silver nitrate can shorten the healing time of ulcers.⁸
• Neonatal umbilical granuloma: Silver nitrate chemical cauterization can be applied to address umbilical granuloma, the most common umbilical abnormality in neonates.⁹
• Cervical ectropion: Silver nitrate chemical cauterization can be used on glandular cells that develop outside of the cervix.¹⁰
• Bartholin abscesses or cysts: Silver nitrate stick insertion can be effective in many patients with Bartholin abscesses or cysts.¹¹

Chemical Cauterization's Application in Wound Care

Silver nitrate for chemical cauterization is indicated for short-term topical use only. It can injure or irritate healthy skin and damage fabric, so it should be handled with care.¹² Those handling silver nitrate should wear protective equipment, as needed. Careful assessment of the wound is essential before treatment to determine whether one treatment is sufficient or whether additional applications will be necessary, although it is not recommended for long-term use. Treatment with silver nitrate can be painful, requiring the preparation of a suitable barrier using petroleum jelly or soft white paraffin as necessary.¹³ Chemical cauterization treatment using silver nitrate frequently requires the following steps⁷:

• Assess the wound and periwound area. Consider whether there may be a need for medication, such as topical anesthesia, before the procedure, to reduce patient discomfort.
• Wash hands thoroughly and put on gloves. If the wound is dressed, remove the dressings following standard removal procedures and wash hands again, and put on new gloves.
• Clean the wound with sterile saline solution following proper wound cleansing procedures. Remove gloves, wash hands again, and put on new gloves.
• Confine the area to be treated by encircling it with a barrier, such as petroleum jelly or an equivalent barrier cream or ointment.
• Cover the wound base tissue with moistened normal saline gauze to protect from spillage. Silver nitrate will stain or burn anything it comes into contact with, thus making it important not to allow drips on any surface.
• Slightly moisten the caustic tip of the silver nitrate applicator stick by dipping the tip into distilled or deionized water.
• Rub and rotate the tip of the applicator along the tissue to be cauterized. Do not touch any other part of the body with the tip. Two minutes of contact time is generally sufficient; monitor patient pain and discomfort throughout the application. Stop if it becomes too painful.
• Use damp saline gauze to clean the treated area after application and pat dry gently. Do not rub or apply friction to the treated area.
• Remove gloves and put on new ones. Apply any other prescribed treatment to the wound base, as necessary.
• After application, follow up with the patient, as necessary. If additional treatments are required, follow the same procedure until the problem has resolved.⁷

References

1. Ho C, Argaez C. Topical Silver Nitrate for the Management of Hemostasis: A Review of Clinical Effectiveness, Cost-Effectiveness, and Guidelines. Ottawa, Canada: Canadian Agency for Drugs and Technologies in Health; 2018. https://www.ncbi.nlm.nih.gov/books/NBK537873/. Accessed December 18, 2020.
2. Staughton J. How does silver nitrate (AgNO3) work on human wounds? Science ABC. 2019. https://www.scienceabc.com/humans/how-does-silver-nitrate-work-on-human…. Accessed December 18, 2020.
3. Lou Z. Hemostasis of idiopathic recurrent epistaxis in children with microwave ablation: a prospective pilot case series. J Otolaryngol Head Neck Surg. 2019;48(1):72. https://doi.org/10.1186/s40463-019-0393-0.
4. Newton E, Lasso A, Petrcich W, Kilty SJ. An outcomes analysis of anterior epistaxis management in the emergency department. J Otolaryngol Head Neck Surg. 2016;45:24. https://doi.org/10.1186/s40463-016-0138-2.
5. WoundSource Editors. What are silver nitrate sticks? WoundSource.com. 2020. https://www.woundsource.com/blog/what-are-silver-nitrate-sticks. Accessed December 18, 2020.
6. Vu P, Faraday R, Vu D, Kim J. Silver nitrate masquerading as a heterotropic ossification. Radiol Case Rep. 2020;15(5):450-453.
7. Morgan N. How to apply silver nitrate. Wound Care Advisor. 2016. http://old.woundcareadvisor.com/how-to-apply-silver-nitrate/#:~:text=To…. Accessed December 19, 2020.
8. Ozler GS. Silver nitrate cauterization: a treatment option for aphthous stomatitis. J Craniomaxillofac9. Ogawa C, Satao Y, Suzuki C, et al. Treatment with silver nitrate versus topical steroid treatment for umbilical granuloma: a non-inferiority randomized control trial. PlosOne. 2018;13(2):e0192688. doi: 10.1371/journal.pone.0192688.
9. Medical News Today. What to know about cervical ectropion. 2019. https://www.medicalnewstoday.com/articles/320298. Accessed December 18, 2020.
10. Yüce K, Zeyneloglu HB, Bükülmez O, Kisnisci HA.. Outpatient management of Bartholin gland abscesses and cysts with silver nitrate. Aust N Z J Obstet Gynaecol. 2008;34(1):93-96.
11. University of Michigan, Michigan Medicine. Silver nitrate topical. https://www.uofmhealth.org/health-library/d04208a1. Accessed December 19, 2020.
12. Clinical pharmacist. Q&A: silver nitrate sticks for treating tissue hypergranulation. Pharm J. 2010;2:231.