With advances in medicine, endotracheal intubation became commonplace in the mid-20th century. It became possible to visualize the internal structure of the body, which revolutionized therapy. One of these advances was the invention of the Miller laryngoscope blade, named after its inventor, Robert A. Miller. These laryngoscope blades are used to lift the epiglottis to visualize the vocal cords while conducting a medical procedure.
In this comprehensive guide, we will delve into various facets, from the anatomy of Miller blades to their distinct properties, advantages, and precautions. Embark on an exploration of their applications, including their significance in pediatric patients.
Let’s discover how these durable and cost-effective instruments are shaping the future of airway management in the realm of medical sciences.
The shape of a Miller laryngoscope blade
The Miller laryngoscope blades are longer in size with a tapered tip proceeded by a rounded bottom. The blades possess a slightly curvy surface that starts 2 inches from the end. Miller laryngoscopic instruments possess straight blades, unlike the Macintosh blades which are curvy. The rigid metal blades have a smooth surface which makes it easy to slip them into the trachea once the technician places the blade into the respiratory pipe. Miller blades possess a secure fitting with no chances of detachment while in use.
Miller laryngoscope blade
Properties of Miller laryngoscope blade
Miller blades possess the following properties:
- Miller laryngoscope blades are latex-free.
- These are single-use instruments but are also available in multiple-use forms.
- Miller laryngoscope blades have a 4 mm acrylic core with a stainless steel body making them durable and corrosion-resistant.
- Miller blades are available in different sizes ranging from 00 to 5.
- Different sizes are color-coded for easy identification.
- No touch hook is attached to avoid the transfer of microbes thus preventing infections.
- A reusable handle enables the surgeon to replace the blades after a single use.
When to use a Miller laryngoscope blade?
Miller laryngoscope blades are employed in conditions when laryngoscopy is recommended by the physician to unveil the causes of troubled breathing or difficulty in swallowing. Symptoms such as continued cough, sudden change in a voice often termed dysphonia or bad breathing might be associated with laryngitis i.e. the inflammation of the larynx which may appear due to multiple reasons including:
- Arytenoid granuloma (Localized tumor at the back of vocal cords)
- Laryngeal papillomatosis (Tumor growth in the voice box, vocal cords, or other parts of the air passageway)
- Spasmodic dysphonia (Speech changes due to the laryngeal spasm caused by neurological issues)
- Vocal cord dysplasia (Pre-cancerous surface changes in the membrane of vocal cords)
- Vocal cord paralysis
- Vocal cord cancer
- Laryngeal cancer
- Polypoid corditis or Reinke’s edema (The development of polyps in the vocal cords)
How to use the Miller laryngoscope blade?
Laryngoscopy using a Miller blade should be conducted in the following way:
- The subject should be fasted for 8 to 12 hours prior to the procedure to reduce the chances of vomiting.
- Ask the subject to lie down on their back.
- The subject must be lightly anesthetized before starting the process.
- Using a cylinder, oxygen must be administered to the patient to avoid hypoxia.
- The laryngoscope should be held by the technician using her dominant hand.
- The subject should be asked to extend his tongue to the left side.
- Now, the Miller blade can be inserted into the patient’s oral cavity from the right side. Make sure to proceed slowly and gently.
- Advance the Miller laryngoscope blade towards the back of the tongue until the epiglottis is reached.
- The tapered tip of the blade should be placed under the epiglottis in such a way that the handle achieves a 45-degree angle.
- Gentle pressure should be applied to lift the epiglottis until the vocal cords are visualized.
- Now, intubation of the endotracheal tube can be done followed by the withdrawal of the blade.
- Detach the blade from its handle and start the cleaning process.
Advantages of Miller laryngoscope blade
The use of Miller laryngoscope blades provides the following advantages:
- The instrument provides a better view of the vocal cords as well as the nearby area as compared to the one visualized by using Macintosh or other laryngoscope blades.
- Its stainless steel body provides durability resulting in long-term utility.
- Miller blades are highly economical.
- Different size ranges allow the physician to choose the most appropriate blade based on its intended use.
- Miller laryngoscope blades are the instrument of choice for conducting laryngoscopy in pediatric patients due to the broader as well as highly flexible epiglottis in infants.
Side effects of Miller laryngoscope blade
Although Miller laryngoscope blades are safe to use during a laryngoscopic process, the following side effects can occur:
- Improper use of the Miller blade can damage the soft tissues of the trachea.
- Too must pressure applied while using the Miller blade can damage the front teeth.
- Improper cleaning of the laryngoscope blades can transfer microbes into the trachea resulting in future infections.
Precautions
The following precautionary measures must be adopted while using a Miller laryngoscope blade:
- The patient’s weight must be kept in mind while selecting the size of the Miller blade to be used.
- The level of visibility achieved by laryngoscopy is dependent on the skeletal as well as soft tissue condition of the subject.
- In the case of a multiple-use laryngoscope blade, proper cleaning and disinfection with enzymatic detergents followed by sterilization are needed.
- The size of the handle which is to be attached to the blades must be evaluated accordingly.
Conclusion
Endotracheal visualization is one of the primary procedures conducted to evaluate the internal structure of the tracheal pipe. To achieve this purpose, various types of laryngoscope blades are put to use, one of which is the Miller laryngoscope blade. It is a durable as well an inexpensive instrument employed to conduct laryngoscopy in adults along with children. Its rust-proof strong structure enables the technicians to handle the instrument firmly while in use. These properties of Miller laryngoscope blades have thus rendered them an instrument of choice for laryngoscopy in medical sciences.
PhD Scholar (Pharmaceutics), MPhil (Pharmaceutics), Pharm D, B. Sc.
Uzma Zafar is a dedicated and highly motivated pharmaceutical professional currently pursuing her PhD in Pharmaceutics at the Punjab University College of Pharmacy, University of the Punjab. With a comprehensive academic and research background, Uzma has consistently excelled in her studies, securing first division throughout her educational journey.
Uzma’s passion for the pharmaceutical field is evident from her active engagement during her Doctor of Pharmacy (Pharm.D) program, where she not only mastered industrial techniques and clinical case studies but also delved into marketing strategies and management skills.
